Xen project Mailing List

On Wed, Mar 28, 2018 at 09:47:41AM +0300, Oleksandr Andrushchenko wrote: > From: Oleksandr Andrushchenko <oleksandr_andrushchenko@xxxxxxxx> > > Add support for Xen para-virtualized frontend display driver. > Accompanying backend [1] is implemented as a user-space application > and its helper library [2], capable of running as a Weston client > or DRM master. > Configuration of both backend and frontend is done via > Xen guest domain configuration options [3]. > > Driver limitations: > 1. Only primary plane without additional properties is supported. > 2. Only one video mode supported which resolution is configured via XenStore. > 3. All CRTCs operate at fixed frequency of 60Hz. > > 1. Implement Xen bus state machine for the frontend driver according to > the state diagram and recovery flow from display para-virtualized > protocol: xen/interface/io/displif.h. > > 2. Read configuration values from Xen store according > to xen/interface/io/displif.h protocol: > - read connector(s) configuration > - read buffer allocation mode (backend/frontend) > > 3. Handle Xen event channels: > - create for all configured connectors and publish > corresponding ring references and event channels in Xen store, > so backend can connect > - implement event channels interrupt handlers > - create and destroy event channels with respect to Xen bus state > > 4. Implement shared buffer handling according to the > para-virtualized display device protocol at xen/interface/io/displif.h: > - handle page directories according to displif protocol: > - allocate and share page directories > - grant references to the required set of pages for the > page directory > - allocate xen balllooned pages via Xen balloon driver > with alloc_xenballooned_pages/free_xenballooned_pages > - grant references to the required set of pages for the > shared buffer itself > - implement pages map/unmap for the buffers allocated by the > backend (gnttab_map_refs/gnttab_unmap_refs) > > 5. Implement kernel modesetiing/connector handling using > DRM simple KMS helper pipeline: > > - implement KMS part of the driver with the help of DRM > simple pipepline helper which is possible due to the fact > that the para-virtualized driver only supports a single > (primary) plane: > - initialize connectors according to XenStore configuration > - handle frame done events from the backend > - create and destroy frame buffers and propagate those > to the backend > - propagate set/reset mode configuration to the backend on display > enable/disable callbacks > - send page flip request to the backend and implement logic for > reporting backend IO errors on prepare fb callback > > - implement virtual connector handling: > - support only pixel formats suitable for single plane modes > - make sure the connector is always connected > - support a single video mode as per para-virtualized driver > configuration > > 6. Implement GEM handling depending on driver mode of operation: > depending on the requirements for the para-virtualized environment, namely > requirements dictated by the accompanying DRM/(v)GPU drivers running in both > host and guest environments, number of operating modes of para-virtualized > display driver are supported: > - display buffers can be allocated by either frontend driver or backend > - display buffers can be allocated to be contiguous in memory or not > > Note! Frontend driver itself has no dependency on contiguous memory for > its operation. > > 6.1. Buffers allocated by the frontend driver. > > The below modes of operation are configured at compile-time via > frontend driver's kernel configuration. > > 6.1.1. Front driver configured to use GEM CMA helpers > This use-case is useful when used with accompanying DRM/vGPU driver in > guest domain which was designed to only work with contiguous buffers, > e.g. DRM driver based on GEM CMA helpers: such drivers can only import > contiguous PRIME buffers, thus requiring frontend driver to provide > such. In order to implement this mode of operation para-virtualized > frontend driver can be configured to use GEM CMA helpers. > > 6.1.2. Front driver doesn't use GEM CMA > If accompanying drivers can cope with non-contiguous memory then, to > lower pressure on CMA subsystem of the kernel, driver can allocate > buffers from system memory. > > Note! If used with accompanying DRM/(v)GPU drivers this mode of operation > may require IOMMU support on the platform, so accompanying DRM/vGPU > hardware can still reach display buffer memory while importing PRIME > buffers from the frontend driver. > > 6.2. Buffers allocated by the backend > > This mode of operation is run-time configured via guest domain configuration > through XenStore entries. > > For systems which do not provide IOMMU support, but having specific > requirements for display buffers it is possible to allocate such buffers > at backend side and share those with the frontend. > For example, if host domain is 1:1 mapped and has DRM/GPU hardware expecting > physically contiguous memory, this allows implementing zero-copying > use-cases. > > Note, while using this scenario the following should be considered: > a) If guest domain dies then pages/grants received from the backend > cannot be claimed back > b) Misbehaving guest may send too many requests to the > backend exhausting its grant references and memory > (consider this from security POV). > > Note! Configuration options 1.1 (contiguous display buffers) and 2 (backend > allocated buffers) are not supported at the same time. > > 7. Handle communication with the backend: > - send requests and wait for the responses according > to the displif protocol > - serialize access to the communication channel > - time-out used for backend communication is set to 3000 ms > - manage display buffers shared with the backend > > [1] https://github.com/xen-troops/displ_be > [2] https://github.com/xen-troops/libxenbe > [3] > https://xenbits.xen.org/gitweb/?p=xen.git;a=blob;f=docs/man/xl.cfg.pod.5.in;h=a699367779e2ae1212ff8f638eff0206ec1a1cc9;hb=refs/heads/master#l1257 > > Signed-off-by: Oleksandr Andrushchenko <oleksandr_andrushchenko@xxxxxxxx> > Reviewed-by: Boris Ostrovsky <boris.ostrovsky@xxxxxxxxxx> kms side looks good now too. Reviewed-by: Daniel Vetter <daniel.vetter@xxxxxxxx> > --- > Documentation/gpu/drivers.rst | 1 + > Documentation/gpu/xen-front.rst | 43 ++ > drivers/gpu/drm/Kconfig | 2 + > drivers/gpu/drm/Makefile | 1 + > drivers/gpu/drm/xen/Kconfig | 30 + > drivers/gpu/drm/xen/Makefile | 16 + > drivers/gpu/drm/xen/xen_drm_front.c | 880 > ++++++++++++++++++++++++++++ > drivers/gpu/drm/xen/xen_drm_front.h | 189 ++++++ > drivers/gpu/drm/xen/xen_drm_front_cfg.c | 77 +++ > drivers/gpu/drm/xen/xen_drm_front_cfg.h | 37 ++ > drivers/gpu/drm/xen/xen_drm_front_conn.c | 115 ++++ > drivers/gpu/drm/xen/xen_drm_front_conn.h | 27 + > drivers/gpu/drm/xen/xen_drm_front_evtchnl.c | 382 ++++++++++++ > drivers/gpu/drm/xen/xen_drm_front_evtchnl.h | 81 +++ > drivers/gpu/drm/xen/xen_drm_front_gem.c | 309 ++++++++++ > drivers/gpu/drm/xen/xen_drm_front_gem.h | 41 ++ > drivers/gpu/drm/xen/xen_drm_front_gem_cma.c | 78 +++ > drivers/gpu/drm/xen/xen_drm_front_kms.c | 371 ++++++++++++ > drivers/gpu/drm/xen/xen_drm_front_kms.h | 27 + > drivers/gpu/drm/xen/xen_drm_front_shbuf.c | 432 ++++++++++++++ > drivers/gpu/drm/xen/xen_drm_front_shbuf.h | 72 +++ > 21 files changed, 3211 insertions(+) > create mode 100644 Documentation/gpu/xen-front.rst > create mode 100644 drivers/gpu/drm/xen/Kconfig > create mode 100644 drivers/gpu/drm/xen/Makefile > create mode 100644 drivers/gpu/drm/xen/xen_drm_front.c > create mode 100644 drivers/gpu/drm/xen/xen_drm_front.h > create mode 100644 drivers/gpu/drm/xen/xen_drm_front_cfg.c > create mode 100644 drivers/gpu/drm/xen/xen_drm_front_cfg.h > create mode 100644 drivers/gpu/drm/xen/xen_drm_front_conn.c > create mode 100644 drivers/gpu/drm/xen/xen_drm_front_conn.h > create mode 100644 drivers/gpu/drm/xen/xen_drm_front_evtchnl.c > create mode 100644 drivers/gpu/drm/xen/xen_drm_front_evtchnl.h > create mode 100644 drivers/gpu/drm/xen/xen_drm_front_gem.c > create mode 100644 drivers/gpu/drm/xen/xen_drm_front_gem.h > create mode 100644 drivers/gpu/drm/xen/xen_drm_front_gem_cma.c > create mode 100644 drivers/gpu/drm/xen/xen_drm_front_kms.c > create mode 100644 drivers/gpu/drm/xen/xen_drm_front_kms.h > create mode 100644 drivers/gpu/drm/xen/xen_drm_front_shbuf.c > create mode 100644 drivers/gpu/drm/xen/xen_drm_front_shbuf.h > > diff --git a/Documentation/gpu/drivers.rst b/Documentation/gpu/drivers.rst > index e8c84419a2a1..d3ab6abae838 100644 > --- a/Documentation/gpu/drivers.rst > +++ b/Documentation/gpu/drivers.rst > @@ -12,6 +12,7 @@ GPU Driver Documentation > tve200 > vc4 > bridge/dw-hdmi > + xen-front > > .. only:: subproject and html > > diff --git a/Documentation/gpu/xen-front.rst b/Documentation/gpu/xen-front.rst > new file mode 100644 > index 000000000000..8188e03c9d23 > --- /dev/null > +++ b/Documentation/gpu/xen-front.rst > @@ -0,0 +1,43 @@ > +==================================== > +Xen para-virtualized frontend driver > +==================================== > + > +This frontend driver implements Xen para-virtualized display > +according to the display protocol described at > +include/xen/interface/io/displif.h > + > +Driver modes of operation in terms of display buffers used > +========================================================== > + > +.. kernel-doc:: drivers/gpu/drm/xen/xen_drm_front.h > + :doc: Driver modes of operation in terms of display buffers used > + > +Buffers allocated by the frontend driver > +---------------------------------------- > + > +.. kernel-doc:: drivers/gpu/drm/xen/xen_drm_front.h > + :doc: Buffers allocated by the frontend driver > + > +With GEM CMA helpers > +~~~~~~~~~~~~~~~~~~~~ > + > +.. kernel-doc:: drivers/gpu/drm/xen/xen_drm_front.h > + :doc: With GEM CMA helpers > + > +Without GEM CMA helpers > +~~~~~~~~~~~~~~~~~~~~~~~ > + > +.. kernel-doc:: drivers/gpu/drm/xen/xen_drm_front.h > + :doc: Without GEM CMA helpers > + > +Buffers allocated by the backend > +-------------------------------- > + > +.. kernel-doc:: drivers/gpu/drm/xen/xen_drm_front.h > + :doc: Buffers allocated by the backend > + > +Driver limitations > +================== > + > +.. kernel-doc:: drivers/gpu/drm/xen/xen_drm_front.h > + :doc: Driver limitations > diff --git a/drivers/gpu/drm/Kconfig b/drivers/gpu/drm/Kconfig > index deeefa7a1773..757825ac60df 100644 > --- a/drivers/gpu/drm/Kconfig > +++ b/drivers/gpu/drm/Kconfig > @@ -289,6 +289,8 @@ source "drivers/gpu/drm/pl111/Kconfig" > > source "drivers/gpu/drm/tve200/Kconfig" > > +source "drivers/gpu/drm/xen/Kconfig" > + > # Keep legacy drivers last > > menuconfig DRM_LEGACY > diff --git a/drivers/gpu/drm/Makefile b/drivers/gpu/drm/Makefile > index 50093ff4479b..9d66657ea117 100644 > --- a/drivers/gpu/drm/Makefile > +++ b/drivers/gpu/drm/Makefile > @@ -103,3 +103,4 @@ obj-$(CONFIG_DRM_MXSFB) += mxsfb/ > obj-$(CONFIG_DRM_TINYDRM) += tinydrm/ > obj-$(CONFIG_DRM_PL111) += pl111/ > obj-$(CONFIG_DRM_TVE200) += tve200/ > +obj-$(CONFIG_DRM_XEN) += xen/ > diff --git a/drivers/gpu/drm/xen/Kconfig b/drivers/gpu/drm/xen/Kconfig > new file mode 100644 > index 000000000000..4f4abc91f3b6 > --- /dev/null > +++ b/drivers/gpu/drm/xen/Kconfig > @@ -0,0 +1,30 @@ > +config DRM_XEN > + bool "DRM Support for Xen guest OS" > + depends on XEN > + help > + Choose this option if you want to enable DRM support > + for Xen. > + > +config DRM_XEN_FRONTEND > + tristate "Para-virtualized frontend driver for Xen guest OS" > + depends on DRM_XEN > + depends on DRM > + select DRM_KMS_HELPER > + select VIDEOMODE_HELPERS > + select XEN_XENBUS_FRONTEND > + help > + Choose this option if you want to enable a para-virtualized > + frontend DRM/KMS driver for Xen guest OSes. > + > +config DRM_XEN_FRONTEND_CMA > + bool "Use DRM CMA to allocate dumb buffers" > + depends on DRM_XEN_FRONTEND > + select DRM_KMS_CMA_HELPER > + select DRM_GEM_CMA_HELPER > + help > + Use DRM CMA helpers to allocate display buffers. > + This is useful for the use-cases when guest driver needs to > + share or export buffers to other drivers which only expect > + contiguous buffers. > + Note: in this mode driver cannot use buffers allocated > + by the backend. > diff --git a/drivers/gpu/drm/xen/Makefile b/drivers/gpu/drm/xen/Makefile > new file mode 100644 > index 000000000000..352730dc6c13 > --- /dev/null > +++ b/drivers/gpu/drm/xen/Makefile > @@ -0,0 +1,16 @@ > +# SPDX-License-Identifier: GPL-2.0 OR MIT > + > +drm_xen_front-objs := xen_drm_front.o \ > + xen_drm_front_kms.o \ > + xen_drm_front_conn.o \ > + xen_drm_front_evtchnl.o \ > + xen_drm_front_shbuf.o \ > + xen_drm_front_cfg.o > + > +ifeq ($(CONFIG_DRM_XEN_FRONTEND_CMA),y) > + drm_xen_front-objs += xen_drm_front_gem_cma.o > +else > + drm_xen_front-objs += xen_drm_front_gem.o > +endif > + > +obj-$(CONFIG_DRM_XEN_FRONTEND) += drm_xen_front.o > diff --git a/drivers/gpu/drm/xen/xen_drm_front.c > b/drivers/gpu/drm/xen/xen_drm_front.c > new file mode 100644 > index 000000000000..b08817e5e35c > --- /dev/null > +++ b/drivers/gpu/drm/xen/xen_drm_front.c > @@ -0,0 +1,880 @@ > +// SPDX-License-Identifier: GPL-2.0 OR MIT > + > +/* > + * Xen para-virtual DRM device > + * > + * Copyright (C) 2016-2018 EPAM Systems Inc. > + * > + * Author: Oleksandr Andrushchenko <oleksandr_andrushchenko@xxxxxxxx> > + */ > + > +#include <drm/drmP.h> > +#include <drm/drm_atomic_helper.h> > +#include <drm/drm_crtc_helper.h> > +#include <drm/drm_gem.h> > +#include <drm/drm_gem_cma_helper.h> > + > +#include <linux/of_device.h> > + > +#include <xen/platform_pci.h> > +#include <xen/xen.h> > +#include <xen/xenbus.h> > + > +#include <xen/interface/io/displif.h> > + > +#include "xen_drm_front.h" > +#include "xen_drm_front_cfg.h" > +#include "xen_drm_front_evtchnl.h" > +#include "xen_drm_front_gem.h" > +#include "xen_drm_front_kms.h" > +#include "xen_drm_front_shbuf.h" > + > +struct xen_drm_front_dbuf { > + struct list_head list; > + uint64_t dbuf_cookie; > + uint64_t fb_cookie; > + struct xen_drm_front_shbuf *shbuf; > +}; > + > +static int dbuf_add_to_list(struct xen_drm_front_info *front_info, > + struct xen_drm_front_shbuf *shbuf, uint64_t dbuf_cookie) > +{ > + struct xen_drm_front_dbuf *dbuf; > + > + dbuf = kzalloc(sizeof(*dbuf), GFP_KERNEL); > + if (!dbuf) > + return -ENOMEM; > + > + dbuf->dbuf_cookie = dbuf_cookie; > + dbuf->shbuf = shbuf; > + list_add(&dbuf->list, &front_info->dbuf_list); > + return 0; > +} > + > +static struct xen_drm_front_dbuf *dbuf_get(struct list_head *dbuf_list, > + uint64_t dbuf_cookie) > +{ > + struct xen_drm_front_dbuf *buf, *q; > + > + list_for_each_entry_safe(buf, q, dbuf_list, list) > + if (buf->dbuf_cookie == dbuf_cookie) > + return buf; > + > + return NULL; > +} > + > +static void dbuf_flush_fb(struct list_head *dbuf_list, uint64_t fb_cookie) > +{ > + struct xen_drm_front_dbuf *buf, *q; > + > + list_for_each_entry_safe(buf, q, dbuf_list, list) > + if (buf->fb_cookie == fb_cookie) > + xen_drm_front_shbuf_flush(buf->shbuf); > +} > + > +static void dbuf_free(struct list_head *dbuf_list, uint64_t dbuf_cookie) > +{ > + struct xen_drm_front_dbuf *buf, *q; > + > + list_for_each_entry_safe(buf, q, dbuf_list, list) > + if (buf->dbuf_cookie == dbuf_cookie) { > + list_del(&buf->list); > + xen_drm_front_shbuf_unmap(buf->shbuf); > + xen_drm_front_shbuf_free(buf->shbuf); > + kfree(buf); > + break; > + } > +} > + > +static void dbuf_free_all(struct list_head *dbuf_list) > +{ > + struct xen_drm_front_dbuf *buf, *q; > + > + list_for_each_entry_safe(buf, q, dbuf_list, list) { > + list_del(&buf->list); > + xen_drm_front_shbuf_unmap(buf->shbuf); > + xen_drm_front_shbuf_free(buf->shbuf); > + kfree(buf); > + } > +} > + > +static struct xendispl_req *be_prepare_req( > + struct xen_drm_front_evtchnl *evtchnl, uint8_t operation) > +{ > + struct xendispl_req *req; > + > + req = RING_GET_REQUEST(&evtchnl->u.req.ring, > + evtchnl->u.req.ring.req_prod_pvt); > + req->operation = operation; > + req->id = evtchnl->evt_next_id++; > + evtchnl->evt_id = req->id; > + return req; > +} > + > +static int be_stream_do_io(struct xen_drm_front_evtchnl *evtchnl, > + struct xendispl_req *req) > +{ > + reinit_completion(&evtchnl->u.req.completion); > + if (unlikely(evtchnl->state != EVTCHNL_STATE_CONNECTED)) > + return -EIO; > + > + xen_drm_front_evtchnl_flush(evtchnl); > + return 0; > +} > + > +static int be_stream_wait_io(struct xen_drm_front_evtchnl *evtchnl) > +{ > + if (wait_for_completion_timeout(&evtchnl->u.req.completion, > + msecs_to_jiffies(XEN_DRM_FRONT_WAIT_BACK_MS)) <= 0) > + return -ETIMEDOUT; > + > + return evtchnl->u.req.resp_status; > +} > + > +int xen_drm_front_mode_set(struct xen_drm_front_drm_pipeline *pipeline, > + uint32_t x, uint32_t y, uint32_t width, uint32_t height, > + uint32_t bpp, uint64_t fb_cookie) > +{ > + struct xen_drm_front_evtchnl *evtchnl; > + struct xen_drm_front_info *front_info; > + struct xendispl_req *req; > + unsigned long flags; > + int ret; > + > + front_info = pipeline->drm_info->front_info; > + evtchnl = &front_info->evt_pairs[pipeline->index].req; > + if (unlikely(!evtchnl)) > + return -EIO; > + > + mutex_lock(&evtchnl->u.req.req_io_lock); > + > + spin_lock_irqsave(&front_info->io_lock, flags); > + req = be_prepare_req(evtchnl, XENDISPL_OP_SET_CONFIG); > + req->op.set_config.x = x; > + req->op.set_config.y = y; > + req->op.set_config.width = width; > + req->op.set_config.height = height; > + req->op.set_config.bpp = bpp; > + req->op.set_config.fb_cookie = fb_cookie; > + > + ret = be_stream_do_io(evtchnl, req); > + spin_unlock_irqrestore(&front_info->io_lock, flags); > + > + if (ret == 0) > + ret = be_stream_wait_io(evtchnl); > + > + mutex_unlock(&evtchnl->u.req.req_io_lock); > + return ret; > +} > + > +static int be_dbuf_create_int(struct xen_drm_front_info *front_info, > + uint64_t dbuf_cookie, uint32_t width, uint32_t height, > + uint32_t bpp, uint64_t size, struct page **pages, > + struct sg_table *sgt) > +{ > + struct xen_drm_front_evtchnl *evtchnl; > + struct xen_drm_front_shbuf *shbuf; > + struct xendispl_req *req; > + struct xen_drm_front_shbuf_cfg buf_cfg; > + unsigned long flags; > + int ret; > + > + evtchnl = &front_info->evt_pairs[GENERIC_OP_EVT_CHNL].req; > + if (unlikely(!evtchnl)) > + return -EIO; > + > + memset(&buf_cfg, 0, sizeof(buf_cfg)); > + buf_cfg.xb_dev = front_info->xb_dev; > + buf_cfg.pages = pages; > + buf_cfg.size = size; > + buf_cfg.sgt = sgt; > + buf_cfg.be_alloc = front_info->cfg.be_alloc; > + > + shbuf = xen_drm_front_shbuf_alloc(&buf_cfg); > + if (!shbuf) > + return -ENOMEM; > + > + ret = dbuf_add_to_list(front_info, shbuf, dbuf_cookie); > + if (ret < 0) { > + xen_drm_front_shbuf_free(shbuf); > + return ret; > + } > + > + mutex_lock(&evtchnl->u.req.req_io_lock); > + > + spin_lock_irqsave(&front_info->io_lock, flags); > + req = be_prepare_req(evtchnl, XENDISPL_OP_DBUF_CREATE); > + req->op.dbuf_create.gref_directory = > + xen_drm_front_shbuf_get_dir_start(shbuf); > + req->op.dbuf_create.buffer_sz = size; > + req->op.dbuf_create.dbuf_cookie = dbuf_cookie; > + req->op.dbuf_create.width = width; > + req->op.dbuf_create.height = height; > + req->op.dbuf_create.bpp = bpp; > + if (buf_cfg.be_alloc) > + req->op.dbuf_create.flags |= XENDISPL_DBUF_FLG_REQ_ALLOC; > + > + ret = be_stream_do_io(evtchnl, req); > + spin_unlock_irqrestore(&front_info->io_lock, flags); > + > + if (ret < 0) > + goto fail; > + > + ret = be_stream_wait_io(evtchnl); > + if (ret < 0) > + goto fail; > + > + ret = xen_drm_front_shbuf_map(shbuf); > + if (ret < 0) > + goto fail; > + > + mutex_unlock(&evtchnl->u.req.req_io_lock); > + return 0; > + > +fail: > + mutex_unlock(&evtchnl->u.req.req_io_lock); > + dbuf_free(&front_info->dbuf_list, dbuf_cookie); > + return ret; > +} > + > +int xen_drm_front_dbuf_create_from_sgt(struct xen_drm_front_info *front_info, > + uint64_t dbuf_cookie, uint32_t width, uint32_t height, > + uint32_t bpp, uint64_t size, struct sg_table *sgt) > +{ > + return be_dbuf_create_int(front_info, dbuf_cookie, width, height, > + bpp, size, NULL, sgt); > +} > + > +int xen_drm_front_dbuf_create_from_pages(struct xen_drm_front_info > *front_info, > + uint64_t dbuf_cookie, uint32_t width, uint32_t height, > + uint32_t bpp, uint64_t size, struct page **pages) > +{ > + return be_dbuf_create_int(front_info, dbuf_cookie, width, height, > + bpp, size, pages, NULL); > +} > + > +static int xen_drm_front_dbuf_destroy(struct xen_drm_front_info *front_info, > + uint64_t dbuf_cookie) > +{ > + struct xen_drm_front_evtchnl *evtchnl; > + struct xendispl_req *req; > + unsigned long flags; > + bool be_alloc; > + int ret; > + > + evtchnl = &front_info->evt_pairs[GENERIC_OP_EVT_CHNL].req; > + if (unlikely(!evtchnl)) > + return -EIO; > + > + be_alloc = front_info->cfg.be_alloc; > + > + /* > + * For the backend allocated buffer release references now, so backend > + * can free the buffer. > + */ > + if (be_alloc) > + dbuf_free(&front_info->dbuf_list, dbuf_cookie); > + > + mutex_lock(&evtchnl->u.req.req_io_lock); > + > + spin_lock_irqsave(&front_info->io_lock, flags); > + req = be_prepare_req(evtchnl, XENDISPL_OP_DBUF_DESTROY); > + req->op.dbuf_destroy.dbuf_cookie = dbuf_cookie; > + > + ret = be_stream_do_io(evtchnl, req); > + spin_unlock_irqrestore(&front_info->io_lock, flags); > + > + if (ret == 0) > + ret = be_stream_wait_io(evtchnl); > + > + /* > + * Do this regardless of communication status with the backend: > + * if we cannot remove remote resources remove what we can locally. > + */ > + if (!be_alloc) > + dbuf_free(&front_info->dbuf_list, dbuf_cookie); > + > + mutex_unlock(&evtchnl->u.req.req_io_lock); > + return ret; > +} > + > +int xen_drm_front_fb_attach(struct xen_drm_front_info *front_info, > + uint64_t dbuf_cookie, uint64_t fb_cookie, uint32_t width, > + uint32_t height, uint32_t pixel_format) > +{ > + struct xen_drm_front_evtchnl *evtchnl; > + struct xen_drm_front_dbuf *buf; > + struct xendispl_req *req; > + unsigned long flags; > + int ret; > + > + evtchnl = &front_info->evt_pairs[GENERIC_OP_EVT_CHNL].req; > + if (unlikely(!evtchnl)) > + return -EIO; > + > + buf = dbuf_get(&front_info->dbuf_list, dbuf_cookie); > + if (!buf) > + return -EINVAL; > + > + buf->fb_cookie = fb_cookie; > + > + mutex_lock(&evtchnl->u.req.req_io_lock); > + > + spin_lock_irqsave(&front_info->io_lock, flags); > + req = be_prepare_req(evtchnl, XENDISPL_OP_FB_ATTACH); > + req->op.fb_attach.dbuf_cookie = dbuf_cookie; > + req->op.fb_attach.fb_cookie = fb_cookie; > + req->op.fb_attach.width = width; > + req->op.fb_attach.height = height; > + req->op.fb_attach.pixel_format = pixel_format; > + > + ret = be_stream_do_io(evtchnl, req); > + spin_unlock_irqrestore(&front_info->io_lock, flags); > + > + if (ret == 0) > + ret = be_stream_wait_io(evtchnl); > + > + mutex_unlock(&evtchnl->u.req.req_io_lock); > + return ret; > +} > + > +int xen_drm_front_fb_detach(struct xen_drm_front_info *front_info, > + uint64_t fb_cookie) > +{ > + struct xen_drm_front_evtchnl *evtchnl; > + struct xendispl_req *req; > + unsigned long flags; > + int ret; > + > + evtchnl = &front_info->evt_pairs[GENERIC_OP_EVT_CHNL].req; > + if (unlikely(!evtchnl)) > + return -EIO; > + > + mutex_lock(&evtchnl->u.req.req_io_lock); > + > + spin_lock_irqsave(&front_info->io_lock, flags); > + req = be_prepare_req(evtchnl, XENDISPL_OP_FB_DETACH); > + req->op.fb_detach.fb_cookie = fb_cookie; > + > + ret = be_stream_do_io(evtchnl, req); > + spin_unlock_irqrestore(&front_info->io_lock, flags); > + > + if (ret == 0) > + ret = be_stream_wait_io(evtchnl); > + > + mutex_unlock(&evtchnl->u.req.req_io_lock); > + return ret; > +} > + > +int xen_drm_front_page_flip(struct xen_drm_front_info *front_info, > + int conn_idx, uint64_t fb_cookie) > +{ > + struct xen_drm_front_evtchnl *evtchnl; > + struct xendispl_req *req; > + unsigned long flags; > + int ret; > + > + if (unlikely(conn_idx >= front_info->num_evt_pairs)) > + return -EINVAL; > + > + dbuf_flush_fb(&front_info->dbuf_list, fb_cookie); > + evtchnl = &front_info->evt_pairs[conn_idx].req; > + > + mutex_lock(&evtchnl->u.req.req_io_lock); > + > + spin_lock_irqsave(&front_info->io_lock, flags); > + req = be_prepare_req(evtchnl, XENDISPL_OP_PG_FLIP); > + req->op.pg_flip.fb_cookie = fb_cookie; > + > + ret = be_stream_do_io(evtchnl, req); > + spin_unlock_irqrestore(&front_info->io_lock, flags); > + > + if (ret == 0) > + ret = be_stream_wait_io(evtchnl); > + > + mutex_unlock(&evtchnl->u.req.req_io_lock); > + return ret; > +} > + > +void xen_drm_front_on_frame_done(struct xen_drm_front_info *front_info, > + int conn_idx, uint64_t fb_cookie) > +{ > + struct xen_drm_front_drm_info *drm_info = front_info->drm_info; > + > + if (unlikely(conn_idx >= front_info->cfg.num_connectors)) > + return; > + > + xen_drm_front_kms_on_frame_done(&drm_info->pipeline[conn_idx], > + fb_cookie); > +} > + > +static int xen_drm_drv_dumb_create(struct drm_file *filp, > + struct drm_device *dev, struct drm_mode_create_dumb *args) > +{ > + struct xen_drm_front_drm_info *drm_info = dev->dev_private; > + struct drm_gem_object *obj; > + int ret; > + > + /* > + * Dumb creation is a two stage process: first we create a fully > + * constructed GEM object which is communicated to the backend, and > + * only after that we can create GEM's handle. This is done so, > + * because of the possible races: once you create a handle it becomes > + * immediately visible to user-space, so the latter can try accessing > + * object without pages etc. > + * For details also see drm_gem_handle_create > + */ > + args->pitch = DIV_ROUND_UP(args->width * args->bpp, 8); > + args->size = args->pitch * args->height; > + > + obj = xen_drm_front_gem_create(dev, args->size); > + if (IS_ERR_OR_NULL(obj)) { > + ret = PTR_ERR(obj); > + goto fail; > + } > + > + /* > + * In case of CONFIG_DRM_XEN_FRONTEND_CMA gem_obj is constructed > + * via DRM CMA helpers and doesn't have ->pages allocated > + * (xendrm_gem_get_pages will return NULL), but instead can provide > + * sg table > + */ > + if (xen_drm_front_gem_get_pages(obj)) > + ret = xen_drm_front_dbuf_create_from_pages( > + drm_info->front_info, > + xen_drm_front_dbuf_to_cookie(obj), > + args->width, args->height, args->bpp, > + args->size, > + xen_drm_front_gem_get_pages(obj)); > + else > + ret = xen_drm_front_dbuf_create_from_sgt( > + drm_info->front_info, > + xen_drm_front_dbuf_to_cookie(obj), > + args->width, args->height, args->bpp, > + args->size, > + xen_drm_front_gem_get_sg_table(obj)); > + if (ret) > + goto fail_backend; > + > + /* This is the tail of GEM object creation */ > + ret = drm_gem_handle_create(filp, obj, &args->handle); > + if (ret) > + goto fail_handle; > + > + /* Drop reference from allocate - handle holds it now */ > + drm_gem_object_put_unlocked(obj); > + return 0; > + > +fail_handle: > + xen_drm_front_dbuf_destroy(drm_info->front_info, > + xen_drm_front_dbuf_to_cookie(obj)); > +fail_backend: > + /* drop reference from allocate */ > + drm_gem_object_put_unlocked(obj); > +fail: > + DRM_ERROR("Failed to create dumb buffer: %d\n", ret); > + return ret; > +} > + > +static void xen_drm_drv_free_object_unlocked(struct drm_gem_object *obj) > +{ > + struct xen_drm_front_drm_info *drm_info = obj->dev->dev_private; > + int idx; > + > + if (drm_dev_enter(obj->dev, &idx)) { > + xen_drm_front_dbuf_destroy(drm_info->front_info, > + xen_drm_front_dbuf_to_cookie(obj)); > + drm_dev_exit(idx); > + } else > + dbuf_free(&drm_info->front_info->dbuf_list, > + xen_drm_front_dbuf_to_cookie(obj)); > + > + xen_drm_front_gem_free_object_unlocked(obj); > +} > + > +static void xen_drm_drv_release(struct drm_device *dev) > +{ > + struct xen_drm_front_drm_info *drm_info = dev->dev_private; > + struct xen_drm_front_info *front_info = drm_info->front_info; > + > + xen_drm_front_kms_fini(drm_info); > + > + drm_atomic_helper_shutdown(dev); > + drm_mode_config_cleanup(dev); > + > + drm_dev_fini(dev); > + kfree(dev); > + > + if (front_info->cfg.be_alloc) > + xenbus_switch_state(front_info->xb_dev, > + XenbusStateInitialising); > + > + kfree(drm_info); > +} > + > +static const struct file_operations xen_drm_dev_fops = { > + .owner = THIS_MODULE, > + .open = drm_open, > + .release = drm_release, > + .unlocked_ioctl = drm_ioctl, > +#ifdef CONFIG_COMPAT > + .compat_ioctl = drm_compat_ioctl, > +#endif > + .poll = drm_poll, > + .read = drm_read, > + .llseek = no_llseek, > +#ifdef CONFIG_DRM_XEN_FRONTEND_CMA > + .mmap = drm_gem_cma_mmap, > +#else > + .mmap = xen_drm_front_gem_mmap, > +#endif > +}; > + > +static const struct vm_operations_struct xen_drm_drv_vm_ops = { > + .open = drm_gem_vm_open, > + .close = drm_gem_vm_close, > +}; > + > +static struct drm_driver xen_drm_driver = { > + .driver_features = DRIVER_GEM | DRIVER_MODESET | > + DRIVER_PRIME | DRIVER_ATOMIC, > + .release = xen_drm_drv_release, > + .gem_vm_ops = &xen_drm_drv_vm_ops, > + .gem_free_object_unlocked = xen_drm_drv_free_object_unlocked, > + .prime_handle_to_fd = drm_gem_prime_handle_to_fd, > + .prime_fd_to_handle = drm_gem_prime_fd_to_handle, > + .gem_prime_import = drm_gem_prime_import, > + .gem_prime_export = drm_gem_prime_export, > + .gem_prime_import_sg_table = xen_drm_front_gem_import_sg_table, > + .gem_prime_get_sg_table = xen_drm_front_gem_get_sg_table, > + .dumb_create = xen_drm_drv_dumb_create, > + .fops = &xen_drm_dev_fops, > + .name = "xendrm-du", > + .desc = "Xen PV DRM Display Unit", > + .date = "20180221", > + .major = 1, > + .minor = 0, > + > +#ifdef CONFIG_DRM_XEN_FRONTEND_CMA > + .gem_prime_vmap = drm_gem_cma_prime_vmap, > + .gem_prime_vunmap = drm_gem_cma_prime_vunmap, > + .gem_prime_mmap = drm_gem_cma_prime_mmap, > +#else > + .gem_prime_vmap = xen_drm_front_gem_prime_vmap, > + .gem_prime_vunmap = xen_drm_front_gem_prime_vunmap, > + .gem_prime_mmap = xen_drm_front_gem_prime_mmap, > +#endif > +}; > + > +static int xen_drm_drv_init(struct xen_drm_front_info *front_info) > +{ > + struct device *dev = &front_info->xb_dev->dev; > + struct xen_drm_front_drm_info *drm_info; > + struct drm_device *drm_dev; > + int ret; > + > + DRM_INFO("Creating %s\n", xen_drm_driver.desc); > + > + drm_info = kzalloc(sizeof(*drm_info), GFP_KERNEL); > + if (!drm_info) { > + ret = -ENOMEM; > + goto fail; > + } > + > + drm_info->front_info = front_info; > + front_info->drm_info = drm_info; > + > + drm_dev = drm_dev_alloc(&xen_drm_driver, dev); > + if (!drm_dev) { > + ret = -ENOMEM; > + goto fail; > + } > + > + drm_info->drm_dev = drm_dev; > + > + drm_dev->dev_private = drm_info; > + > + ret = xen_drm_front_kms_init(drm_info); > + if (ret) { > + DRM_ERROR("Failed to initialize DRM/KMS, ret %d\n", ret); > + goto fail_modeset; > + } > + > + ret = drm_dev_register(drm_dev, 0); > + if (ret) > + goto fail_register; > + > + DRM_INFO("Initialized %s %d.%d.%d %s on minor %d\n", > + xen_drm_driver.name, xen_drm_driver.major, > + xen_drm_driver.minor, xen_drm_driver.patchlevel, > + xen_drm_driver.date, drm_dev->primary->index); > + > + return 0; > + > +fail_register: > + drm_dev_unregister(drm_dev); > +fail_modeset: > + drm_kms_helper_poll_fini(drm_dev); > + drm_mode_config_cleanup(drm_dev); > +fail: > + kfree(drm_info); > + return ret; > +} > + > +static void xen_drm_drv_fini(struct xen_drm_front_info *front_info) > +{ > + struct xen_drm_front_drm_info *drm_info = front_info->drm_info; > + struct drm_device *dev; > + > + if (!drm_info) > + return; > + > + dev = drm_info->drm_dev; > + if (!dev) > + return; > + > + /* Nothing to do if device is already unplugged */ > + if (drm_dev_is_unplugged(dev)) > + return; > + > + drm_kms_helper_poll_fini(dev); > + drm_dev_unplug(dev); > + > + front_info->drm_info = NULL; > + > + xen_drm_front_evtchnl_free_all(front_info); > + dbuf_free_all(&front_info->dbuf_list); > + > + /* > + * If we are not using backend allocated buffers, then tell the > + * backend we are ready to (re)initialize. Otherwise, wait for > + * drm_driver.release. > + */ > + if (!front_info->cfg.be_alloc) > + xenbus_switch_state(front_info->xb_dev, > + XenbusStateInitialising); > +} > + > +static int displback_initwait(struct xen_drm_front_info *front_info) > +{ > + struct xen_drm_front_cfg *cfg = &front_info->cfg; > + int ret; > + > + cfg->front_info = front_info; > + ret = xen_drm_front_cfg_card(front_info, cfg); > + if (ret < 0) > + return ret; > + > + DRM_INFO("Have %d conector(s)\n", cfg->num_connectors); > + /* Create event channels for all connectors and publish */ > + ret = xen_drm_front_evtchnl_create_all(front_info); > + if (ret < 0) > + return ret; > + > + return xen_drm_front_evtchnl_publish_all(front_info); > +} > + > +static int displback_connect(struct xen_drm_front_info *front_info) > +{ > + xen_drm_front_evtchnl_set_state(front_info, EVTCHNL_STATE_CONNECTED); > + return xen_drm_drv_init(front_info); > +} > + > +static void displback_disconnect(struct xen_drm_front_info *front_info) > +{ > + if (!front_info->drm_info) > + return; > + > + /* Tell the backend to wait until we release the DRM driver. */ > + xenbus_switch_state(front_info->xb_dev, XenbusStateReconfiguring); > + > + xen_drm_drv_fini(front_info); > +} > + > +static void displback_changed(struct xenbus_device *xb_dev, > + enum xenbus_state backend_state) > +{ > + struct xen_drm_front_info *front_info = dev_get_drvdata(&xb_dev->dev); > + int ret; > + > + DRM_DEBUG("Backend state is %s, front is %s\n", > + xenbus_strstate(backend_state), > + xenbus_strstate(xb_dev->state)); > + > + switch (backend_state) { > + case XenbusStateReconfiguring: > + /* fall through */ > + case XenbusStateReconfigured: > + /* fall through */ > + case XenbusStateInitialised: > + break; > + > + case XenbusStateInitialising: > + if (xb_dev->state == XenbusStateReconfiguring) > + break; > + > + /* recovering after backend unexpected closure */ > + displback_disconnect(front_info); > + break; > + > + case XenbusStateInitWait: > + if (xb_dev->state == XenbusStateReconfiguring) > + break; > + > + /* recovering after backend unexpected closure */ > + displback_disconnect(front_info); > + if (xb_dev->state != XenbusStateInitialising) > + break; > + > + ret = displback_initwait(front_info); > + if (ret < 0) > + xenbus_dev_fatal(xb_dev, ret, > + "initializing frontend"); > + else > + xenbus_switch_state(xb_dev, XenbusStateInitialised); > + break; > + > + case XenbusStateConnected: > + if (xb_dev->state != XenbusStateInitialised) > + break; > + > + ret = displback_connect(front_info); > + if (ret < 0) { > + displback_disconnect(front_info); > + xenbus_dev_fatal(xb_dev, ret, > + "initializing DRM driver"); > + } else > + xenbus_switch_state(xb_dev, XenbusStateConnected); > + break; > + > + case XenbusStateClosing: > + /* > + * in this state backend starts freeing resources, > + * so let it go into closed state, so we can also > + * remove ours > + */ > + break; > + > + case XenbusStateUnknown: > + /* fall through */ > + case XenbusStateClosed: > + if (xb_dev->state == XenbusStateClosed) > + break; > + > + displback_disconnect(front_info); > + break; > + } > +} > + > +static int xen_drv_probe(struct xenbus_device *xb_dev, > + const struct xenbus_device_id *id) > +{ > + struct xen_drm_front_info *front_info; > + struct device *dev = &xb_dev->dev; > + int ret; > + > + /* > + * The device is not spawn from a device tree, so arch_setup_dma_ops > + * is not called, thus leaving the device with dummy DMA ops. > + * This makes the device return error on PRIME buffer import, which > + * is not correct: to fix this call of_dma_configure() with a NULL > + * node to set default DMA ops. > + */ > + dev->bus->force_dma = true; > + dev->coherent_dma_mask = DMA_BIT_MASK(32); > + ret = of_dma_configure(dev, NULL); > + if (ret < 0) { > + DRM_ERROR("Cannot setup DMA ops, ret %d", ret); > + return ret; > + } > + > + front_info = devm_kzalloc(&xb_dev->dev, > + sizeof(*front_info), GFP_KERNEL); > + if (!front_info) > + return -ENOMEM; > + > + front_info->xb_dev = xb_dev; > + spin_lock_init(&front_info->io_lock); > + INIT_LIST_HEAD(&front_info->dbuf_list); > + dev_set_drvdata(&xb_dev->dev, front_info); > + > + return xenbus_switch_state(xb_dev, XenbusStateInitialising); > +} > + > +static int xen_drv_remove(struct xenbus_device *dev) > +{ > + struct xen_drm_front_info *front_info = dev_get_drvdata(&dev->dev); > + int to = 100; > + > + xenbus_switch_state(dev, XenbusStateClosing); > + > + /* > + * On driver removal it is disconnected from XenBus, > + * so no backend state change events come via .otherend_changed > + * callback. This prevents us from exiting gracefully, e.g. > + * signaling the backend to free event channels, waiting for its > + * state to change to XenbusStateClosed and cleaning at our end. > + * Normally when front driver removed backend will finally go into > + * XenbusStateInitWait state. > + * > + * Workaround: read backend's state manually and wait with time-out. > + */ > + while ((xenbus_read_unsigned(front_info->xb_dev->otherend, > + "state", XenbusStateUnknown) != XenbusStateInitWait) && > + to--) > + msleep(10); > + > + if (!to) > + DRM_ERROR("Backend state is %s while removing driver\n", > + xenbus_strstate(xenbus_read_unsigned( > + front_info->xb_dev->otherend, > + "state", XenbusStateUnknown))); > + > + xen_drm_drv_fini(front_info); > + xenbus_frontend_closed(dev); > + return 0; > +} > + > +static const struct xenbus_device_id xen_driver_ids[] = { > + { XENDISPL_DRIVER_NAME }, > + { "" } > +}; > + > +static struct xenbus_driver xen_driver = { > + .ids = xen_driver_ids, > + .probe = xen_drv_probe, > + .remove = xen_drv_remove, > + .otherend_changed = displback_changed, > +}; > + > +static int __init xen_drv_init(void) > +{ > + /* At the moment we only support case with XEN_PAGE_SIZE == PAGE_SIZE */ > + if (XEN_PAGE_SIZE != PAGE_SIZE) { > + DRM_ERROR(XENDISPL_DRIVER_NAME ": different kernel and Xen page > sizes are not supported: XEN_PAGE_SIZE (%lu) != PAGE_SIZE (%lu)\n", > + XEN_PAGE_SIZE, PAGE_SIZE); > + return -ENODEV; > + } > + > + if (!xen_domain()) > + return -ENODEV; > + > + if (!xen_has_pv_devices()) > + return -ENODEV; > + > + DRM_INFO("Registering XEN PV " XENDISPL_DRIVER_NAME "\n"); > + return xenbus_register_frontend(&xen_driver); > +} > + > +static void __exit xen_drv_fini(void) > +{ > + DRM_INFO("Unregistering XEN PV " XENDISPL_DRIVER_NAME "\n"); > + xenbus_unregister_driver(&xen_driver); > +} > + > +module_init(xen_drv_init); > +module_exit(xen_drv_fini); > + > +MODULE_DESCRIPTION("Xen para-virtualized display device frontend"); > +MODULE_LICENSE("GPL"); > +MODULE_ALIAS("xen:"XENDISPL_DRIVER_NAME); > diff --git a/drivers/gpu/drm/xen/xen_drm_front.h > b/drivers/gpu/drm/xen/xen_drm_front.h > new file mode 100644 > index 000000000000..2d03de288f96 > --- /dev/null > +++ b/drivers/gpu/drm/xen/xen_drm_front.h > @@ -0,0 +1,189 @@ > +/* SPDX-License-Identifier: GPL-2.0 OR MIT */ > + > +/* > + * Xen para-virtual DRM device > + * > + * Copyright (C) 2016-2018 EPAM Systems Inc. > + * > + * Author: Oleksandr Andrushchenko <oleksandr_andrushchenko@xxxxxxxx> > + */ > + > +#ifndef __XEN_DRM_FRONT_H_ > +#define __XEN_DRM_FRONT_H_ > + > +#include <drm/drmP.h> > +#include <drm/drm_simple_kms_helper.h> > + > +#include <linux/scatterlist.h> > + > +#include "xen_drm_front_cfg.h" > + > +/** > + * DOC: Driver modes of operation in terms of display buffers used > + * > + * Depending on the requirements for the para-virtualized environment, namely > + * requirements dictated by the accompanying DRM/(v)GPU drivers running in > both > + * host and guest environments, number of operating modes of para-virtualized > + * display driver are supported: > + * > + * - display buffers can be allocated by either frontend driver or backend > + * - display buffers can be allocated to be contiguous in memory or not > + * > + * Note! Frontend driver itself has no dependency on contiguous memory for > + * its operation. > + */ > + > +/** > + * DOC: Buffers allocated by the frontend driver > + * > + * The below modes of operation are configured at compile-time via > + * frontend driver's kernel configuration: > + */ > + > +/** > + * DOC: With GEM CMA helpers > + * > + * This use-case is useful when used with accompanying DRM/vGPU driver in > + * guest domain which was designed to only work with contiguous buffers, > + * e.g. DRM driver based on GEM CMA helpers: such drivers can only import > + * contiguous PRIME buffers, thus requiring frontend driver to provide > + * such. In order to implement this mode of operation para-virtualized > + * frontend driver can be configured to use GEM CMA helpers. > + */ > + > +/** > + * DOC: Without GEM CMA helpers > + * > + * If accompanying drivers can cope with non-contiguous memory then, to > + * lower pressure on CMA subsystem of the kernel, driver can allocate > + * buffers from system memory. > + * > + * Note! If used with accompanying DRM/(v)GPU drivers this mode of operation > + * may require IOMMU support on the platform, so accompanying DRM/vGPU > + * hardware can still reach display buffer memory while importing PRIME > + * buffers from the frontend driver. > + */ > + > +/** > + * DOC: Buffers allocated by the backend > + * > + * This mode of operation is run-time configured via guest domain > configuration > + * through XenStore entries. > + * > + * For systems which do not provide IOMMU support, but having specific > + * requirements for display buffers it is possible to allocate such buffers > + * at backend side and share those with the frontend. > + * For example, if host domain is 1:1 mapped and has DRM/GPU hardware > expecting > + * physically contiguous memory, this allows implementing zero-copying > + * use-cases. > + * > + * Note, while using this scenario the following should be considered: > + * > + * #. If guest domain dies then pages/grants received from the backend > + * cannot be claimed back > + * > + * #. Misbehaving guest may send too many requests to the > + * backend exhausting its grant references and memory > + * (consider this from security POV) > + */ > + > +/** > + * DOC: Driver limitations > + * > + * #. Only primary plane without additional properties is supported. > + * > + * #. Only one video mode per connector supported which is configured via > XenStore. > + * > + * #. All CRTCs operate at fixed frequency of 60Hz. > + */ > + > +/* timeout in ms to wait for backend to respond */ > +#define XEN_DRM_FRONT_WAIT_BACK_MS 3000 > + > +#ifndef GRANT_INVALID_REF > +/* > + * Note on usage of grant reference 0 as invalid grant reference: > + * grant reference 0 is valid, but never exposed to a PV driver, > + * because of the fact it is already in use/reserved by the PV console. > + */ > +#define GRANT_INVALID_REF 0 > +#endif > + > +struct xen_drm_front_info { > + struct xenbus_device *xb_dev; > + struct xen_drm_front_drm_info *drm_info; > + > + /* to protect data between backend IO code and interrupt handler */ > + spinlock_t io_lock; > + > + int num_evt_pairs; > + struct xen_drm_front_evtchnl_pair *evt_pairs; > + struct xen_drm_front_cfg cfg; > + > + /* display buffers */ > + struct list_head dbuf_list; > +}; > + > +struct xen_drm_front_drm_pipeline { > + struct xen_drm_front_drm_info *drm_info; > + > + int index; > + > + struct drm_simple_display_pipe pipe; > + > + struct drm_connector conn; > + /* These are only for connector mode checking */ > + int width, height; > + > + struct drm_pending_vblank_event *pending_event; > + > + struct delayed_work pflip_to_worker; > + > + bool conn_connected; > +}; > + > +struct xen_drm_front_drm_info { > + struct xen_drm_front_info *front_info; > + struct drm_device *drm_dev; > + > + struct xen_drm_front_drm_pipeline pipeline[XEN_DRM_FRONT_MAX_CRTCS]; > +}; > + > +static inline uint64_t xen_drm_front_fb_to_cookie( > + struct drm_framebuffer *fb) > +{ > + return (uint64_t)fb; > +} > + > +static inline uint64_t xen_drm_front_dbuf_to_cookie( > + struct drm_gem_object *gem_obj) > +{ > + return (uint64_t)gem_obj; > +} > + > +int xen_drm_front_mode_set(struct xen_drm_front_drm_pipeline *pipeline, > + uint32_t x, uint32_t y, uint32_t width, uint32_t height, > + uint32_t bpp, uint64_t fb_cookie); > + > +int xen_drm_front_dbuf_create_from_sgt(struct xen_drm_front_info *front_info, > + uint64_t dbuf_cookie, uint32_t width, uint32_t height, > + uint32_t bpp, uint64_t size, struct sg_table *sgt); > + > +int xen_drm_front_dbuf_create_from_pages(struct xen_drm_front_info > *front_info, > + uint64_t dbuf_cookie, uint32_t width, uint32_t height, > + uint32_t bpp, uint64_t size, struct page **pages); > + > +int xen_drm_front_fb_attach(struct xen_drm_front_info *front_info, > + uint64_t dbuf_cookie, uint64_t fb_cookie, uint32_t width, > + uint32_t height, uint32_t pixel_format); > + > +int xen_drm_front_fb_detach(struct xen_drm_front_info *front_info, > + uint64_t fb_cookie); > + > +int xen_drm_front_page_flip(struct xen_drm_front_info *front_info, > + int conn_idx, uint64_t fb_cookie); > + > +void xen_drm_front_on_frame_done(struct xen_drm_front_info *front_info, > + int conn_idx, uint64_t fb_cookie); > + > +#endif /* __XEN_DRM_FRONT_H_ */ > diff --git a/drivers/gpu/drm/xen/xen_drm_front_cfg.c > b/drivers/gpu/drm/xen/xen_drm_front_cfg.c > new file mode 100644 > index 000000000000..9a0b2b8e6169 > --- /dev/null > +++ b/drivers/gpu/drm/xen/xen_drm_front_cfg.c > @@ -0,0 +1,77 @@ > +// SPDX-License-Identifier: GPL-2.0 OR MIT > + > +/* > + * Xen para-virtual DRM device > + * > + * Copyright (C) 2016-2018 EPAM Systems Inc. > + * > + * Author: Oleksandr Andrushchenko <oleksandr_andrushchenko@xxxxxxxx> > + */ > + > +#include <drm/drmP.h> > + > +#include <linux/device.h> > + > +#include <xen/interface/io/displif.h> > +#include <xen/xenbus.h> > + > +#include "xen_drm_front.h" > +#include "xen_drm_front_cfg.h" > + > +static int cfg_connector(struct xen_drm_front_info *front_info, > + struct xen_drm_front_cfg_connector *connector, > + const char *path, int index) > +{ > + char *connector_path; > + > + connector_path = devm_kasprintf(&front_info->xb_dev->dev, > + GFP_KERNEL, "%s/%d", path, index); > + if (!connector_path) > + return -ENOMEM; > + > + if (xenbus_scanf(XBT_NIL, connector_path, XENDISPL_FIELD_RESOLUTION, > + "%d" XENDISPL_RESOLUTION_SEPARATOR "%d", > + &connector->width, &connector->height) < 0) { > + /* either no entry configured or wrong resolution set */ > + connector->width = 0; > + connector->height = 0; > + return -EINVAL; > + } > + > + connector->xenstore_path = connector_path; > + > + DRM_INFO("Connector %s: resolution %dx%d\n", > + connector_path, connector->width, connector->height); > + return 0; > +} > + > +int xen_drm_front_cfg_card(struct xen_drm_front_info *front_info, > + struct xen_drm_front_cfg *cfg) > +{ > + struct xenbus_device *xb_dev = front_info->xb_dev; > + int ret, i; > + > + if (xenbus_read_unsigned(front_info->xb_dev->nodename, > + XENDISPL_FIELD_BE_ALLOC, 0)) { > + DRM_INFO("Backend can provide display buffers\n"); > + cfg->be_alloc = true; > + } > + > + cfg->num_connectors = 0; > + for (i = 0; i < ARRAY_SIZE(cfg->connectors); i++) { > + ret = cfg_connector(front_info, > + &cfg->connectors[i], xb_dev->nodename, i); > + if (ret < 0) > + break; > + cfg->num_connectors++; > + } > + > + if (!cfg->num_connectors) { > + DRM_ERROR("No connector(s) configured at %s\n", > + xb_dev->nodename); > + return -ENODEV; > + } > + > + return 0; > +} > + > diff --git a/drivers/gpu/drm/xen/xen_drm_front_cfg.h > b/drivers/gpu/drm/xen/xen_drm_front_cfg.h > new file mode 100644 > index 000000000000..6e7af670f8cd > --- /dev/null > +++ b/drivers/gpu/drm/xen/xen_drm_front_cfg.h > @@ -0,0 +1,37 @@ > +/* SPDX-License-Identifier: GPL-2.0 OR MIT */ > + > +/* > + * Xen para-virtual DRM device > + * > + * Copyright (C) 2016-2018 EPAM Systems Inc. > + * > + * Author: Oleksandr Andrushchenko <oleksandr_andrushchenko@xxxxxxxx> > + */ > + > +#ifndef __XEN_DRM_FRONT_CFG_H_ > +#define __XEN_DRM_FRONT_CFG_H_ > + > +#include <linux/types.h> > + > +#define XEN_DRM_FRONT_MAX_CRTCS 4 > + > +struct xen_drm_front_cfg_connector { > + int width; > + int height; > + char *xenstore_path; > +}; > + > +struct xen_drm_front_cfg { > + struct xen_drm_front_info *front_info; > + /* number of connectors in this configuration */ > + int num_connectors; > + /* connector configurations */ > + struct xen_drm_front_cfg_connector connectors[XEN_DRM_FRONT_MAX_CRTCS]; > + /* set if dumb buffers are allocated externally on backend side */ > + bool be_alloc; > +}; > + > +int xen_drm_front_cfg_card(struct xen_drm_front_info *front_info, > + struct xen_drm_front_cfg *cfg); > + > +#endif /* __XEN_DRM_FRONT_CFG_H_ */ > diff --git a/drivers/gpu/drm/xen/xen_drm_front_conn.c > b/drivers/gpu/drm/xen/xen_drm_front_conn.c > new file mode 100644 > index 000000000000..b5d0b27983b8 > --- /dev/null > +++ b/drivers/gpu/drm/xen/xen_drm_front_conn.c > @@ -0,0 +1,115 @@ > +// SPDX-License-Identifier: GPL-2.0 OR MIT > + > +/* > + * Xen para-virtual DRM device > + * > + * Copyright (C) 2016-2018 EPAM Systems Inc. > + * > + * Author: Oleksandr Andrushchenko <oleksandr_andrushchenko@xxxxxxxx> > + */ > + > +#include <drm/drm_atomic_helper.h> > +#include <drm/drm_crtc_helper.h> > + > +#include <video/videomode.h> > + > +#include "xen_drm_front.h" > +#include "xen_drm_front_conn.h" > +#include "xen_drm_front_kms.h" > + > +static struct xen_drm_front_drm_pipeline * > +to_xen_drm_pipeline(struct drm_connector *connector) > +{ > + return container_of(connector, struct xen_drm_front_drm_pipeline, conn); > +} > + > +static const uint32_t plane_formats[] = { > + DRM_FORMAT_RGB565, > + DRM_FORMAT_RGB888, > + DRM_FORMAT_XRGB8888, > + DRM_FORMAT_ARGB8888, > + DRM_FORMAT_XRGB4444, > + DRM_FORMAT_ARGB4444, > + DRM_FORMAT_XRGB1555, > + DRM_FORMAT_ARGB1555, > +}; > + > +const uint32_t *xen_drm_front_conn_get_formats(int *format_count) > +{ > + *format_count = ARRAY_SIZE(plane_formats); > + return plane_formats; > +} > + > +static int connector_detect(struct drm_connector *connector, > + struct drm_modeset_acquire_ctx *ctx, > + bool force) > +{ > + struct xen_drm_front_drm_pipeline *pipeline = > + to_xen_drm_pipeline(connector); > + > + if (drm_dev_is_unplugged(connector->dev)) > + pipeline->conn_connected = false; > + > + return pipeline->conn_connected ? connector_status_connected : > + connector_status_disconnected; > +} > + > +#define XEN_DRM_CRTC_VREFRESH_HZ 60 > + > +static int connector_get_modes(struct drm_connector *connector) > +{ > + struct xen_drm_front_drm_pipeline *pipeline = > + to_xen_drm_pipeline(connector); > + struct drm_display_mode *mode; > + struct videomode videomode; > + int width, height; > + > + mode = drm_mode_create(connector->dev); > + if (!mode) > + return 0; > + > + memset(&videomode, 0, sizeof(videomode)); > + videomode.hactive = pipeline->width; > + videomode.vactive = pipeline->height; > + width = videomode.hactive + videomode.hfront_porch + > + videomode.hback_porch + videomode.hsync_len; > + height = videomode.vactive + videomode.vfront_porch + > + videomode.vback_porch + videomode.vsync_len; > + videomode.pixelclock = width * height * XEN_DRM_CRTC_VREFRESH_HZ; > + mode->type = DRM_MODE_TYPE_PREFERRED | DRM_MODE_TYPE_DRIVER; > + > + drm_display_mode_from_videomode(&videomode, mode); > + drm_mode_probed_add(connector, mode); > + return 1; > +} > + > +static const struct drm_connector_helper_funcs connector_helper_funcs = { > + .get_modes = connector_get_modes, > + .detect_ctx = connector_detect, > +}; > + > +static const struct drm_connector_funcs connector_funcs = { > + .dpms = drm_helper_connector_dpms, > + .fill_modes = drm_helper_probe_single_connector_modes, > + .destroy = drm_connector_cleanup, > + .reset = drm_atomic_helper_connector_reset, > + .atomic_duplicate_state = drm_atomic_helper_connector_duplicate_state, > + .atomic_destroy_state = drm_atomic_helper_connector_destroy_state, > +}; > + > +int xen_drm_front_conn_init(struct xen_drm_front_drm_info *drm_info, > + struct drm_connector *connector) > +{ > + struct xen_drm_front_drm_pipeline *pipeline = > + to_xen_drm_pipeline(connector); > + > + drm_connector_helper_add(connector, &connector_helper_funcs); > + > + pipeline->conn_connected = true; > + > + connector->polled = DRM_CONNECTOR_POLL_CONNECT | > + DRM_CONNECTOR_POLL_DISCONNECT; > + > + return drm_connector_init(drm_info->drm_dev, connector, > + &connector_funcs, DRM_MODE_CONNECTOR_VIRTUAL); > +} > diff --git a/drivers/gpu/drm/xen/xen_drm_front_conn.h > b/drivers/gpu/drm/xen/xen_drm_front_conn.h > new file mode 100644 > index 000000000000..f38c4b6db5df > --- /dev/null > +++ b/drivers/gpu/drm/xen/xen_drm_front_conn.h > @@ -0,0 +1,27 @@ > +/* SPDX-License-Identifier: GPL-2.0 OR MIT */ > + > +/* > + * Xen para-virtual DRM device > + * > + * Copyright (C) 2016-2018 EPAM Systems Inc. > + * > + * Author: Oleksandr Andrushchenko <oleksandr_andrushchenko@xxxxxxxx> > + */ > + > +#ifndef __XEN_DRM_FRONT_CONN_H_ > +#define __XEN_DRM_FRONT_CONN_H_ > + > +#include <drm/drmP.h> > +#include <drm/drm_crtc.h> > +#include <drm/drm_encoder.h> > + > +#include <linux/wait.h> > + > +struct xen_drm_front_drm_info; > + > +int xen_drm_front_conn_init(struct xen_drm_front_drm_info *drm_info, > + struct drm_connector *connector); > + > +const uint32_t *xen_drm_front_conn_get_formats(int *format_count); > + > +#endif /* __XEN_DRM_FRONT_CONN_H_ */ > diff --git a/drivers/gpu/drm/xen/xen_drm_front_evtchnl.c > b/drivers/gpu/drm/xen/xen_drm_front_evtchnl.c > new file mode 100644 > index 000000000000..e521785fd22b > --- /dev/null > +++ b/drivers/gpu/drm/xen/xen_drm_front_evtchnl.c > @@ -0,0 +1,382 @@ > +// SPDX-License-Identifier: GPL-2.0 OR MIT > + > +/* > + * Xen para-virtual DRM device > + * > + * Copyright (C) 2016-2018 EPAM Systems Inc. > + * > + * Author: Oleksandr Andrushchenko <oleksandr_andrushchenko@xxxxxxxx> > + */ > + > +#include <drm/drmP.h> > + > +#include <linux/errno.h> > +#include <linux/irq.h> > + > +#include <xen/xenbus.h> > +#include <xen/events.h> > +#include <xen/grant_table.h> > + > +#include "xen_drm_front.h" > +#include "xen_drm_front_evtchnl.h" > + > +static irqreturn_t evtchnl_interrupt_ctrl(int irq, void *dev_id) > +{ > + struct xen_drm_front_evtchnl *evtchnl = dev_id; > + struct xen_drm_front_info *front_info = evtchnl->front_info; > + struct xendispl_resp *resp; > + RING_IDX i, rp; > + unsigned long flags; > + > + if (unlikely(evtchnl->state != EVTCHNL_STATE_CONNECTED)) > + return IRQ_HANDLED; > + > + spin_lock_irqsave(&front_info->io_lock, flags); > + > +again: > + rp = evtchnl->u.req.ring.sring->rsp_prod; > + /* ensure we see queued responses up to rp */ > + virt_rmb(); > + > + for (i = evtchnl->u.req.ring.rsp_cons; i != rp; i++) { > + resp = RING_GET_RESPONSE(&evtchnl->u.req.ring, i); > + if (unlikely(resp->id != evtchnl->evt_id)) > + continue; > + > + switch (resp->operation) { > + case XENDISPL_OP_PG_FLIP: > + case XENDISPL_OP_FB_ATTACH: > + case XENDISPL_OP_FB_DETACH: > + case XENDISPL_OP_DBUF_CREATE: > + case XENDISPL_OP_DBUF_DESTROY: > + case XENDISPL_OP_SET_CONFIG: > + evtchnl->u.req.resp_status = resp->status; > + complete(&evtchnl->u.req.completion); > + break; > + > + default: > + DRM_ERROR("Operation %d is not supported\n", > + resp->operation); > + break; > + } > + } > + > + evtchnl->u.req.ring.rsp_cons = i; > + > + if (i != evtchnl->u.req.ring.req_prod_pvt) { > + int more_to_do; > + > + RING_FINAL_CHECK_FOR_RESPONSES(&evtchnl->u.req.ring, > + more_to_do); > + if (more_to_do) > + goto again; > + } else > + evtchnl->u.req.ring.sring->rsp_event = i + 1; > + > + spin_unlock_irqrestore(&front_info->io_lock, flags); > + return IRQ_HANDLED; > +} > + > +static irqreturn_t evtchnl_interrupt_evt(int irq, void *dev_id) > +{ > + struct xen_drm_front_evtchnl *evtchnl = dev_id; > + struct xen_drm_front_info *front_info = evtchnl->front_info; > + struct xendispl_event_page *page = evtchnl->u.evt.page; > + uint32_t cons, prod; > + unsigned long flags; > + > + if (unlikely(evtchnl->state != EVTCHNL_STATE_CONNECTED)) > + return IRQ_HANDLED; > + > + spin_lock_irqsave(&front_info->io_lock, flags); > + > + prod = page->in_prod; > + /* ensure we see ring contents up to prod */ > + virt_rmb(); > + if (prod == page->in_cons) > + goto out; > + > + for (cons = page->in_cons; cons != prod; cons++) { > + struct xendispl_evt *event; > + > + event = &XENDISPL_IN_RING_REF(page, cons); > + if (unlikely(event->id != evtchnl->evt_id++)) > + continue; > + > + switch (event->type) { > + case XENDISPL_EVT_PG_FLIP: > + xen_drm_front_on_frame_done(front_info, evtchnl->index, > + event->op.pg_flip.fb_cookie); > + break; > + } > + } > + page->in_cons = cons; > + /* ensure ring contents */ > + virt_wmb(); > + > +out: > + spin_unlock_irqrestore(&front_info->io_lock, flags); > + return IRQ_HANDLED; > +} > + > +static void evtchnl_free(struct xen_drm_front_info *front_info, > + struct xen_drm_front_evtchnl *evtchnl) > +{ > + unsigned long page = 0; > + > + if (evtchnl->type == EVTCHNL_TYPE_REQ) > + page = (unsigned long)evtchnl->u.req.ring.sring; > + else if (evtchnl->type == EVTCHNL_TYPE_EVT) > + page = (unsigned long)evtchnl->u.evt.page; > + if (!page) > + return; > + > + evtchnl->state = EVTCHNL_STATE_DISCONNECTED; > + > + if (evtchnl->type == EVTCHNL_TYPE_REQ) { > + /* release all who still waits for response if any */ > + evtchnl->u.req.resp_status = -EIO; > + complete_all(&evtchnl->u.req.completion); > + } > + > + if (evtchnl->irq) > + unbind_from_irqhandler(evtchnl->irq, evtchnl); > + > + if (evtchnl->port) > + xenbus_free_evtchn(front_info->xb_dev, evtchnl->port); > + > + /* end access and free the page */ > + if (evtchnl->gref != GRANT_INVALID_REF) > + gnttab_end_foreign_access(evtchnl->gref, 0, page); > + > + memset(evtchnl, 0, sizeof(*evtchnl)); > +} > + > +static int evtchnl_alloc(struct xen_drm_front_info *front_info, int index, > + struct xen_drm_front_evtchnl *evtchnl, > + enum xen_drm_front_evtchnl_type type) > +{ > + struct xenbus_device *xb_dev = front_info->xb_dev; > + unsigned long page; > + grant_ref_t gref; > + irq_handler_t handler; > + int ret; > + > + memset(evtchnl, 0, sizeof(*evtchnl)); > + evtchnl->type = type; > + evtchnl->index = index; > + evtchnl->front_info = front_info; > + evtchnl->state = EVTCHNL_STATE_DISCONNECTED; > + evtchnl->gref = GRANT_INVALID_REF; > + > + page = get_zeroed_page(GFP_NOIO | __GFP_HIGH); > + if (!page) { > + ret = -ENOMEM; > + goto fail; > + } > + > + if (type == EVTCHNL_TYPE_REQ) { > + struct xen_displif_sring *sring; > + > + init_completion(&evtchnl->u.req.completion); > + mutex_init(&evtchnl->u.req.req_io_lock); > + sring = (struct xen_displif_sring *)page; > + SHARED_RING_INIT(sring); > + FRONT_RING_INIT(&evtchnl->u.req.ring, > + sring, XEN_PAGE_SIZE); > + > + ret = xenbus_grant_ring(xb_dev, sring, 1, &gref); > + if (ret < 0) > + goto fail; > + > + handler = evtchnl_interrupt_ctrl; > + } else { > + evtchnl->u.evt.page = (struct xendispl_event_page *)page; > + > + ret = gnttab_grant_foreign_access(xb_dev->otherend_id, > + virt_to_gfn((void *)page), 0); > + if (ret < 0) > + goto fail; > + > + gref = ret; > + handler = evtchnl_interrupt_evt; > + } > + evtchnl->gref = gref; > + > + ret = xenbus_alloc_evtchn(xb_dev, &evtchnl->port); > + if (ret < 0) > + goto fail; > + > + ret = bind_evtchn_to_irqhandler(evtchnl->port, > + handler, 0, xb_dev->devicetype, evtchnl); > + if (ret < 0) > + goto fail; > + > + evtchnl->irq = ret; > + return 0; > + > +fail: > + DRM_ERROR("Failed to allocate ring: %d\n", ret); > + return ret; > +} > + > +int xen_drm_front_evtchnl_create_all(struct xen_drm_front_info *front_info) > +{ > + struct xen_drm_front_cfg *cfg; > + int ret, conn; > + > + cfg = &front_info->cfg; > + > + front_info->evt_pairs = kcalloc(cfg->num_connectors, > + sizeof(struct xen_drm_front_evtchnl_pair), GFP_KERNEL); > + if (!front_info->evt_pairs) { > + ret = -ENOMEM; > + goto fail; > + } > + > + for (conn = 0; conn < cfg->num_connectors; conn++) { > + ret = evtchnl_alloc(front_info, conn, > + &front_info->evt_pairs[conn].req, > + EVTCHNL_TYPE_REQ); > + if (ret < 0) { > + DRM_ERROR("Error allocating control channel\n"); > + goto fail; > + } > + > + ret = evtchnl_alloc(front_info, conn, > + &front_info->evt_pairs[conn].evt, > + EVTCHNL_TYPE_EVT); > + if (ret < 0) { > + DRM_ERROR("Error allocating in-event channel\n"); > + goto fail; > + } > + } > + front_info->num_evt_pairs = cfg->num_connectors; > + return 0; > + > +fail: > + xen_drm_front_evtchnl_free_all(front_info); > + return ret; > +} > + > +static int evtchnl_publish(struct xenbus_transaction xbt, > + struct xen_drm_front_evtchnl *evtchnl, const char *path, > + const char *node_ring, const char *node_chnl) > +{ > + struct xenbus_device *xb_dev = evtchnl->front_info->xb_dev; > + int ret; > + > + /* write control channel ring reference */ > + ret = xenbus_printf(xbt, path, node_ring, "%u", evtchnl->gref); > + if (ret < 0) { > + xenbus_dev_error(xb_dev, ret, "writing ring-ref"); > + return ret; > + } > + > + /* write event channel ring reference */ > + ret = xenbus_printf(xbt, path, node_chnl, "%u", evtchnl->port); > + if (ret < 0) { > + xenbus_dev_error(xb_dev, ret, "writing event channel"); > + return ret; > + } > + > + return 0; > +} > + > +int xen_drm_front_evtchnl_publish_all(struct xen_drm_front_info *front_info) > +{ > + struct xenbus_transaction xbt; > + struct xen_drm_front_cfg *plat_data; > + int ret, conn; > + > + plat_data = &front_info->cfg; > + > +again: > + ret = xenbus_transaction_start(&xbt); > + if (ret < 0) { > + xenbus_dev_fatal(front_info->xb_dev, ret, > + "starting transaction"); > + return ret; > + } > + > + for (conn = 0; conn < plat_data->num_connectors; conn++) { > + ret = evtchnl_publish(xbt, > + &front_info->evt_pairs[conn].req, > + plat_data->connectors[conn].xenstore_path, > + XENDISPL_FIELD_REQ_RING_REF, > + XENDISPL_FIELD_REQ_CHANNEL); > + if (ret < 0) > + goto fail; > + > + ret = evtchnl_publish(xbt, > + &front_info->evt_pairs[conn].evt, > + plat_data->connectors[conn].xenstore_path, > + XENDISPL_FIELD_EVT_RING_REF, > + XENDISPL_FIELD_EVT_CHANNEL); > + if (ret < 0) > + goto fail; > + } > + > + ret = xenbus_transaction_end(xbt, 0); > + if (ret < 0) { > + if (ret == -EAGAIN) > + goto again; > + > + xenbus_dev_fatal(front_info->xb_dev, ret, > + "completing transaction"); > + goto fail_to_end; > + } > + > + return 0; > + > +fail: > + xenbus_transaction_end(xbt, 1); > + > +fail_to_end: > + xenbus_dev_fatal(front_info->xb_dev, ret, "writing Xen store"); > + return ret; > +} > + > +void xen_drm_front_evtchnl_flush(struct xen_drm_front_evtchnl *evtchnl) > +{ > + int notify; > + > + evtchnl->u.req.ring.req_prod_pvt++; > + RING_PUSH_REQUESTS_AND_CHECK_NOTIFY(&evtchnl->u.req.ring, notify); > + if (notify) > + notify_remote_via_irq(evtchnl->irq); > +} > + > +void xen_drm_front_evtchnl_set_state(struct xen_drm_front_info *front_info, > + enum xen_drm_front_evtchnl_state state) > +{ > + unsigned long flags; > + int i; > + > + if (!front_info->evt_pairs) > + return; > + > + spin_lock_irqsave(&front_info->io_lock, flags); > + for (i = 0; i < front_info->num_evt_pairs; i++) { > + front_info->evt_pairs[i].req.state = state; > + front_info->evt_pairs[i].evt.state = state; > + } > + spin_unlock_irqrestore(&front_info->io_lock, flags); > + > +} > + > +void xen_drm_front_evtchnl_free_all(struct xen_drm_front_info *front_info) > +{ > + int i; > + > + if (!front_info->evt_pairs) > + return; > + > + for (i = 0; i < front_info->num_evt_pairs; i++) { > + evtchnl_free(front_info, &front_info->evt_pairs[i].req); > + evtchnl_free(front_info, &front_info->evt_pairs[i].evt); > + } > + > + kfree(front_info->evt_pairs); > + front_info->evt_pairs = NULL; > +} > diff --git a/drivers/gpu/drm/xen/xen_drm_front_evtchnl.h > b/drivers/gpu/drm/xen/xen_drm_front_evtchnl.h > new file mode 100644 > index 000000000000..38ceacb8e9c1 > --- /dev/null > +++ b/drivers/gpu/drm/xen/xen_drm_front_evtchnl.h > @@ -0,0 +1,81 @@ > +/* SPDX-License-Identifier: GPL-2.0 OR MIT */ > + > +/* > + * Xen para-virtual DRM device > + * > + * Copyright (C) 2016-2018 EPAM Systems Inc. > + * > + * Author: Oleksandr Andrushchenko <oleksandr_andrushchenko@xxxxxxxx> > + */ > + > +#ifndef __XEN_DRM_FRONT_EVTCHNL_H_ > +#define __XEN_DRM_FRONT_EVTCHNL_H_ > + > +#include <linux/completion.h> > +#include <linux/types.h> > + > +#include <xen/interface/io/ring.h> > +#include <xen/interface/io/displif.h> > + > +/* > + * All operations which are not connector oriented use this ctrl event > channel, > + * e.g. fb_attach/destroy which belong to a DRM device, not to a CRTC. > + */ > +#define GENERIC_OP_EVT_CHNL 0 > + > +enum xen_drm_front_evtchnl_state { > + EVTCHNL_STATE_DISCONNECTED, > + EVTCHNL_STATE_CONNECTED, > +}; > + > +enum xen_drm_front_evtchnl_type { > + EVTCHNL_TYPE_REQ, > + EVTCHNL_TYPE_EVT, > +}; > + > +struct xen_drm_front_drm_info; > + > +struct xen_drm_front_evtchnl { > + struct xen_drm_front_info *front_info; > + int gref; > + int port; > + int irq; > + int index; > + enum xen_drm_front_evtchnl_state state; > + enum xen_drm_front_evtchnl_type type; > + /* either response id or incoming event id */ > + uint16_t evt_id; > + /* next request id or next expected event id */ > + uint16_t evt_next_id; > + union { > + struct { > + struct xen_displif_front_ring ring; > + struct completion completion; > + /* latest response status */ > + int resp_status; > + /* serializer for backend IO: request/response */ > + struct mutex req_io_lock; > + } req; > + struct { > + struct xendispl_event_page *page; > + } evt; > + } u; > +}; > + > +struct xen_drm_front_evtchnl_pair { > + struct xen_drm_front_evtchnl req; > + struct xen_drm_front_evtchnl evt; > +}; > + > +int xen_drm_front_evtchnl_create_all(struct xen_drm_front_info *front_info); > + > +int xen_drm_front_evtchnl_publish_all(struct xen_drm_front_info *front_info); > + > +void xen_drm_front_evtchnl_flush(struct xen_drm_front_evtchnl *evtchnl); > + > +void xen_drm_front_evtchnl_set_state(struct xen_drm_front_info *front_info, > + enum xen_drm_front_evtchnl_state state); > + > +void xen_drm_front_evtchnl_free_all(struct xen_drm_front_info *front_info); > + > +#endif /* __XEN_DRM_FRONT_EVTCHNL_H_ */ > diff --git a/drivers/gpu/drm/xen/xen_drm_front_gem.c > b/drivers/gpu/drm/xen/xen_drm_front_gem.c > new file mode 100644 > index 000000000000..ad3c6fe4afa3 > --- /dev/null > +++ b/drivers/gpu/drm/xen/xen_drm_front_gem.c > @@ -0,0 +1,309 @@ > +// SPDX-License-Identifier: GPL-2.0 OR MIT > + > +/* > + * Xen para-virtual DRM device > + * > + * Copyright (C) 2016-2018 EPAM Systems Inc. > + * > + * Author: Oleksandr Andrushchenko <oleksandr_andrushchenko@xxxxxxxx> > + */ > + > +#include "xen_drm_front_gem.h" > + > +#include <drm/drmP.h> > +#include <drm/drm_crtc_helper.h> > +#include <drm/drm_fb_helper.h> > +#include <drm/drm_gem.h> > + > +#include <linux/dma-buf.h> > +#include <linux/scatterlist.h> > +#include <linux/shmem_fs.h> > + > +#include <xen/balloon.h> > + > +#include "xen_drm_front.h" > +#include "xen_drm_front_shbuf.h" > + > +struct xen_gem_object { > + struct drm_gem_object base; > + > + size_t num_pages; > + struct page **pages; > + > + /* set for buffers allocated by the backend */ > + bool be_alloc; > + > + /* this is for imported PRIME buffer */ > + struct sg_table *sgt_imported; > +}; > + > +static inline struct xen_gem_object *to_xen_gem_obj( > + struct drm_gem_object *gem_obj) > +{ > + return container_of(gem_obj, struct xen_gem_object, base); > +} > + > +static int gem_alloc_pages_array(struct xen_gem_object *xen_obj, > + size_t buf_size) > +{ > + xen_obj->num_pages = DIV_ROUND_UP(buf_size, PAGE_SIZE); > + xen_obj->pages = kvmalloc_array(xen_obj->num_pages, > + sizeof(struct page *), GFP_KERNEL); > + return xen_obj->pages == NULL ? -ENOMEM : 0; > +} > + > +static void gem_free_pages_array(struct xen_gem_object *xen_obj) > +{ > + kvfree(xen_obj->pages); > + xen_obj->pages = NULL; > +} > + > +static struct xen_gem_object *gem_create_obj(struct drm_device *dev, > + size_t size) > +{ > + struct xen_gem_object *xen_obj; > + int ret; > + > + xen_obj = kzalloc(sizeof(*xen_obj), GFP_KERNEL); > + if (!xen_obj) > + return ERR_PTR(-ENOMEM); > + > + ret = drm_gem_object_init(dev, &xen_obj->base, size); > + if (ret < 0) { > + kfree(xen_obj); > + return ERR_PTR(ret); > + } > + > + return xen_obj; > +} > + > +static struct xen_gem_object *gem_create(struct drm_device *dev, size_t size) > +{ > + struct xen_drm_front_drm_info *drm_info = dev->dev_private; > + struct xen_gem_object *xen_obj; > + int ret; > + > + size = round_up(size, PAGE_SIZE); > + xen_obj = gem_create_obj(dev, size); > + if (IS_ERR_OR_NULL(xen_obj)) > + return xen_obj; > + > + if (drm_info->front_info->cfg.be_alloc) { > + /* > + * backend will allocate space for this buffer, so > + * only allocate array of pointers to pages > + */ > + ret = gem_alloc_pages_array(xen_obj, size); > + if (ret < 0) > + goto fail; > + > + /* > + * allocate ballooned pages which will be used to map > + * grant references provided by the backend > + */ > + ret = alloc_xenballooned_pages(xen_obj->num_pages, > + xen_obj->pages); > + if (ret < 0) { > + DRM_ERROR("Cannot allocate %zu ballooned pages: %d\n", > + xen_obj->num_pages, ret); > + gem_free_pages_array(xen_obj); > + goto fail; > + } > + > + xen_obj->be_alloc = true; > + return xen_obj; > + } > + /* > + * need to allocate backing pages now, so we can share those > + * with the backend > + */ > + xen_obj->num_pages = DIV_ROUND_UP(size, PAGE_SIZE); > + xen_obj->pages = drm_gem_get_pages(&xen_obj->base); > + if (IS_ERR_OR_NULL(xen_obj->pages)) { > + ret = PTR_ERR(xen_obj->pages); > + xen_obj->pages = NULL; > + goto fail; > + } > + > + return xen_obj; > + > +fail: > + DRM_ERROR("Failed to allocate buffer with size %zu\n", size); > + return ERR_PTR(ret); > +} > + > +struct drm_gem_object *xen_drm_front_gem_create(struct drm_device *dev, > + size_t size) > +{ > + struct xen_gem_object *xen_obj; > + > + xen_obj = gem_create(dev, size); > + if (IS_ERR_OR_NULL(xen_obj)) > + return ERR_CAST(xen_obj); > + > + return &xen_obj->base; > +} > + > +void xen_drm_front_gem_free_object_unlocked(struct drm_gem_object *gem_obj) > +{ > + struct xen_gem_object *xen_obj = to_xen_gem_obj(gem_obj); > + > + if (xen_obj->base.import_attach) { > + drm_prime_gem_destroy(&xen_obj->base, xen_obj->sgt_imported); > + gem_free_pages_array(xen_obj); > + } else { > + if (xen_obj->pages) { > + if (xen_obj->be_alloc) { > + free_xenballooned_pages(xen_obj->num_pages, > + xen_obj->pages); > + gem_free_pages_array(xen_obj); > + } else > + drm_gem_put_pages(&xen_obj->base, > + xen_obj->pages, true, false); > + } > + } > + drm_gem_object_release(gem_obj); > + kfree(xen_obj); > +} > + > +struct page **xen_drm_front_gem_get_pages(struct drm_gem_object *gem_obj) > +{ > + struct xen_gem_object *xen_obj = to_xen_gem_obj(gem_obj); > + > + return xen_obj->pages; > +} > + > +struct sg_table *xen_drm_front_gem_get_sg_table(struct drm_gem_object > *gem_obj) > +{ > + struct xen_gem_object *xen_obj = to_xen_gem_obj(gem_obj); > + > + if (!xen_obj->pages) > + return NULL; > + > + return drm_prime_pages_to_sg(xen_obj->pages, xen_obj->num_pages); > +} > + > +struct drm_gem_object *xen_drm_front_gem_import_sg_table(struct drm_device > *dev, > + struct dma_buf_attachment *attach, struct sg_table *sgt) > +{ > + struct xen_drm_front_drm_info *drm_info = dev->dev_private; > + struct xen_gem_object *xen_obj; > + size_t size; > + int ret; > + > + size = attach->dmabuf->size; > + xen_obj = gem_create_obj(dev, size); > + if (IS_ERR_OR_NULL(xen_obj)) > + return ERR_CAST(xen_obj); > + > + ret = gem_alloc_pages_array(xen_obj, size); > + if (ret < 0) > + return ERR_PTR(ret); > + > + xen_obj->sgt_imported = sgt; > + > + ret = drm_prime_sg_to_page_addr_arrays(sgt, xen_obj->pages, > + NULL, xen_obj->num_pages); > + if (ret < 0) > + return ERR_PTR(ret); > + > + /* > + * N.B. Although we have an API to create display buffer from sgt > + * we use pages API, because we still need those for GEM handling, > + * e.g. for mapping etc. > + */ > + ret = xen_drm_front_dbuf_create_from_pages(drm_info->front_info, > + xen_drm_front_dbuf_to_cookie(&xen_obj->base), > + 0, 0, 0, size, xen_obj->pages); > + if (ret < 0) > + return ERR_PTR(ret); > + > + DRM_DEBUG("Imported buffer of size %zu with nents %u\n", > + size, sgt->nents); > + > + return &xen_obj->base; > +} > + > +static int gem_mmap_obj(struct xen_gem_object *xen_obj, > + struct vm_area_struct *vma) > +{ > + unsigned long addr = vma->vm_start; > + int i; > + > + /* > + * clear the VM_PFNMAP flag that was set by drm_gem_mmap(), and set the > + * vm_pgoff (used as a fake buffer offset by DRM) to 0 as we want to map > + * the whole buffer. > + */ > + vma->vm_flags &= ~VM_PFNMAP; > + vma->vm_flags |= VM_MIXEDMAP; > + vma->vm_pgoff = 0; > + vma->vm_page_prot = > pgprot_writecombine(vm_get_page_prot(vma->vm_flags)); > + > + /* > + * vm_operations_struct.fault handler will be called if CPU access > + * to VM is here. For GPUs this isn't the case, because CPU > + * doesn't touch the memory. Insert pages now, so both CPU and GPU are > + * happy. > + * FIXME: as we insert all the pages now then no .fault handler must > + * be called, so don't provide one > + */ > + for (i = 0; i < xen_obj->num_pages; i++) { > + int ret; > + > + ret = vm_insert_page(vma, addr, xen_obj->pages[i]); > + if (ret < 0) { > + DRM_ERROR("Failed to insert pages into vma: %d\n", ret); > + return ret; > + } > + > + addr += PAGE_SIZE; > + } > + return 0; > +} > + > +int xen_drm_front_gem_mmap(struct file *filp, struct vm_area_struct *vma) > +{ > + struct xen_gem_object *xen_obj; > + struct drm_gem_object *gem_obj; > + int ret; > + > + ret = drm_gem_mmap(filp, vma); > + if (ret < 0) > + return ret; > + > + gem_obj = vma->vm_private_data; > + xen_obj = to_xen_gem_obj(gem_obj); > + return gem_mmap_obj(xen_obj, vma); > +} > + > +void *xen_drm_front_gem_prime_vmap(struct drm_gem_object *gem_obj) > +{ > + struct xen_gem_object *xen_obj = to_xen_gem_obj(gem_obj); > + > + if (!xen_obj->pages) > + return NULL; > + > + return vmap(xen_obj->pages, xen_obj->num_pages, > + VM_MAP, pgprot_writecombine(PAGE_KERNEL)); > +} > + > +void xen_drm_front_gem_prime_vunmap(struct drm_gem_object *gem_obj, > + void *vaddr) > +{ > + vunmap(vaddr); > +} > + > +int xen_drm_front_gem_prime_mmap(struct drm_gem_object *gem_obj, > + struct vm_area_struct *vma) > +{ > + struct xen_gem_object *xen_obj; > + int ret; > + > + ret = drm_gem_mmap_obj(gem_obj, gem_obj->size, vma); > + if (ret < 0) > + return ret; > + > + xen_obj = to_xen_gem_obj(gem_obj); > + return gem_mmap_obj(xen_obj, vma); > +} > diff --git a/drivers/gpu/drm/xen/xen_drm_front_gem.h > b/drivers/gpu/drm/xen/xen_drm_front_gem.h > new file mode 100644 > index 000000000000..a94130a1d73e > --- /dev/null > +++ b/drivers/gpu/drm/xen/xen_drm_front_gem.h > @@ -0,0 +1,41 @@ > +/* SPDX-License-Identifier: GPL-2.0 OR MIT */ > + > +/* > + * Xen para-virtual DRM device > + * > + * Copyright (C) 2016-2018 EPAM Systems Inc. > + * > + * Author: Oleksandr Andrushchenko <oleksandr_andrushchenko@xxxxxxxx> > + */ > + > +#ifndef __XEN_DRM_FRONT_GEM_H > +#define __XEN_DRM_FRONT_GEM_H > + > +#include <drm/drmP.h> > + > +struct drm_gem_object *xen_drm_front_gem_create(struct drm_device *dev, > + size_t size); > + > +struct drm_gem_object *xen_drm_front_gem_import_sg_table(struct drm_device > *dev, > + struct dma_buf_attachment *attach, struct sg_table *sgt); > + > +struct sg_table *xen_drm_front_gem_get_sg_table(struct drm_gem_object > *gem_obj); > + > +struct page **xen_drm_front_gem_get_pages(struct drm_gem_object *obj); > + > +void xen_drm_front_gem_free_object_unlocked(struct drm_gem_object *gem_obj); > + > +#ifndef CONFIG_DRM_XEN_FRONTEND_CMA > + > +int xen_drm_front_gem_mmap(struct file *filp, struct vm_area_struct *vma); > + > +void *xen_drm_front_gem_prime_vmap(struct drm_gem_object *gem_obj); > + > +void xen_drm_front_gem_prime_vunmap(struct drm_gem_object *gem_obj, > + void *vaddr); > + > +int xen_drm_front_gem_prime_mmap(struct drm_gem_object *gem_obj, > + struct vm_area_struct *vma); > +#endif > + > +#endif /* __XEN_DRM_FRONT_GEM_H */ > diff --git a/drivers/gpu/drm/xen/xen_drm_front_gem_cma.c > b/drivers/gpu/drm/xen/xen_drm_front_gem_cma.c > new file mode 100644 > index 000000000000..e0ca1e113df9 > --- /dev/null > +++ b/drivers/gpu/drm/xen/xen_drm_front_gem_cma.c > @@ -0,0 +1,78 @@ > +// SPDX-License-Identifier: GPL-2.0 OR MIT > + > +/* > + * Xen para-virtual DRM device > + * > + * Copyright (C) 2016-2018 EPAM Systems Inc. > + * > + * Author: Oleksandr Andrushchenko <oleksandr_andrushchenko@xxxxxxxx> > + */ > + > +#include <drm/drmP.h> > +#include <drm/drm_gem.h> > +#include <drm/drm_fb_cma_helper.h> > +#include <drm/drm_gem_cma_helper.h> > + > +#include "xen_drm_front.h" > +#include "xen_drm_front_gem.h" > + > +struct drm_gem_object *xen_drm_front_gem_import_sg_table(struct drm_device > *dev, > + struct dma_buf_attachment *attach, struct sg_table *sgt) > +{ > + struct xen_drm_front_drm_info *drm_info = dev->dev_private; > + struct drm_gem_object *gem_obj; > + struct drm_gem_cma_object *cma_obj; > + int ret; > + > + gem_obj = drm_gem_cma_prime_import_sg_table(dev, attach, sgt); > + if (IS_ERR_OR_NULL(gem_obj)) > + return gem_obj; > + > + cma_obj = to_drm_gem_cma_obj(gem_obj); > + > + ret = xen_drm_front_dbuf_create_from_sgt( > + drm_info->front_info, > + xen_drm_front_dbuf_to_cookie(gem_obj), > + 0, 0, 0, gem_obj->size, > + drm_gem_cma_prime_get_sg_table(gem_obj)); > + if (ret < 0) > + return ERR_PTR(ret); > + > + DRM_DEBUG("Imported CMA buffer of size %zu\n", gem_obj->size); > + > + return gem_obj; > +} > + > +struct sg_table *xen_drm_front_gem_get_sg_table(struct drm_gem_object > *gem_obj) > +{ > + return drm_gem_cma_prime_get_sg_table(gem_obj); > +} > + > +struct drm_gem_object *xen_drm_front_gem_create(struct drm_device *dev, > + size_t size) > +{ > + struct xen_drm_front_drm_info *drm_info = dev->dev_private; > + struct drm_gem_cma_object *cma_obj; > + > + if (drm_info->front_info->cfg.be_alloc) { > + /* This use-case is not yet supported and probably won't be */ > + DRM_ERROR("Backend allocated buffers and CMA helpers are not > supported at the same time\n"); > + return ERR_PTR(-EINVAL); > + } > + > + cma_obj = drm_gem_cma_create(dev, size); > + if (IS_ERR_OR_NULL(cma_obj)) > + return ERR_CAST(cma_obj); > + > + return &cma_obj->base; > +} > + > +void xen_drm_front_gem_free_object_unlocked(struct drm_gem_object *gem_obj) > +{ > + drm_gem_cma_free_object(gem_obj); > +} > + > +struct page **xen_drm_front_gem_get_pages(struct drm_gem_object *gem_obj) > +{ > + return NULL; > +} > diff --git a/drivers/gpu/drm/xen/xen_drm_front_kms.c > b/drivers/gpu/drm/xen/xen_drm_front_kms.c > new file mode 100644 > index 000000000000..545049dfaf0a > --- /dev/null > +++ b/drivers/gpu/drm/xen/xen_drm_front_kms.c > @@ -0,0 +1,371 @@ > +// SPDX-License-Identifier: GPL-2.0 OR MIT > + > +/* > + * Xen para-virtual DRM device > + * > + * Copyright (C) 2016-2018 EPAM Systems Inc. > + * > + * Author: Oleksandr Andrushchenko <oleksandr_andrushchenko@xxxxxxxx> > + */ > + > +#include "xen_drm_front_kms.h" > + > +#include <drm/drmP.h> > +#include <drm/drm_atomic.h> > +#include <drm/drm_atomic_helper.h> > +#include <drm/drm_crtc_helper.h> > +#include <drm/drm_gem.h> > +#include <drm/drm_gem_framebuffer_helper.h> > + > +#include "xen_drm_front.h" > +#include "xen_drm_front_conn.h" > + > +/* > + * Timeout in ms to wait for frame done event from the backend: > + * must be a bit more than IO time-out > + */ > +#define FRAME_DONE_TO_MS (XEN_DRM_FRONT_WAIT_BACK_MS + 100) > + > +static struct xen_drm_front_drm_pipeline * > +to_xen_drm_pipeline(struct drm_simple_display_pipe *pipe) > +{ > + return container_of(pipe, struct xen_drm_front_drm_pipeline, pipe); > +} > + > +static void fb_destroy(struct drm_framebuffer *fb) > +{ > + struct xen_drm_front_drm_info *drm_info = fb->dev->dev_private; > + int idx; > + > + if (drm_dev_enter(fb->dev, &idx)) { > + xen_drm_front_fb_detach(drm_info->front_info, > + xen_drm_front_fb_to_cookie(fb)); > + drm_dev_exit(idx); > + } > + drm_gem_fb_destroy(fb); > +} > + > +static struct drm_framebuffer_funcs fb_funcs = { > + .destroy = fb_destroy, > +}; > + > +static struct drm_framebuffer *fb_create(struct drm_device *dev, > + struct drm_file *filp, const struct drm_mode_fb_cmd2 *mode_cmd) > +{ > + struct xen_drm_front_drm_info *drm_info = dev->dev_private; > + static struct drm_framebuffer *fb; > + struct drm_gem_object *gem_obj; > + int ret; > + > + fb = drm_gem_fb_create_with_funcs(dev, filp, mode_cmd, &fb_funcs); > + if (IS_ERR_OR_NULL(fb)) > + return fb; > + > + gem_obj = drm_gem_object_lookup(filp, mode_cmd->handles[0]); > + if (!gem_obj) { > + DRM_ERROR("Failed to lookup GEM object\n"); > + ret = -ENOENT; > + goto fail; > + } > + > + drm_gem_object_put_unlocked(gem_obj); > + > + ret = xen_drm_front_fb_attach( > + drm_info->front_info, > + xen_drm_front_dbuf_to_cookie(gem_obj), > + xen_drm_front_fb_to_cookie(fb), > + fb->width, fb->height, fb->format->format); > + if (ret < 0) { > + DRM_ERROR("Back failed to attach FB %p: %d\n", fb, ret); > + goto fail; > + } > + > + return fb; > + > +fail: > + drm_gem_fb_destroy(fb); > + return ERR_PTR(ret); > +} > + > +static const struct drm_mode_config_funcs mode_config_funcs = { > + .fb_create = fb_create, > + .atomic_check = drm_atomic_helper_check, > + .atomic_commit = drm_atomic_helper_commit, > +}; > + > +static void send_pending_event(struct xen_drm_front_drm_pipeline *pipeline) > +{ > + struct drm_crtc *crtc = &pipeline->pipe.crtc; > + struct drm_device *dev = crtc->dev; > + unsigned long flags; > + > + spin_lock_irqsave(&dev->event_lock, flags); > + if (pipeline->pending_event) > + drm_crtc_send_vblank_event(crtc, pipeline->pending_event); > + pipeline->pending_event = NULL; > + spin_unlock_irqrestore(&dev->event_lock, flags); > +} > + > +static void display_enable(struct drm_simple_display_pipe *pipe, > + struct drm_crtc_state *crtc_state) > +{ > + struct xen_drm_front_drm_pipeline *pipeline = > + to_xen_drm_pipeline(pipe); > + struct drm_crtc *crtc = &pipe->crtc; > + struct drm_framebuffer *fb = pipe->plane.state->fb; > + int ret, idx; > + > + if (!drm_dev_enter(pipe->crtc.dev, &idx)) > + return; > + > + ret = xen_drm_front_mode_set(pipeline, > + crtc->x, crtc->y, fb->width, fb->height, > + fb->format->cpp[0] * 8, > + xen_drm_front_fb_to_cookie(fb)); > + > + if (ret) { > + DRM_ERROR("Failed to enable display: %d\n", ret); > + pipeline->conn_connected = false; > + } > + > + drm_dev_exit(idx); > +} > + > +static void display_disable(struct drm_simple_display_pipe *pipe) > +{ > + struct xen_drm_front_drm_pipeline *pipeline = > + to_xen_drm_pipeline(pipe); > + int ret = 0, idx; > + > + if (drm_dev_enter(pipe->crtc.dev, &idx)) { > + ret = xen_drm_front_mode_set(pipeline, 0, 0, 0, 0, 0, > + xen_drm_front_fb_to_cookie(NULL)); > + drm_dev_exit(idx); > + } > + if (ret) > + DRM_ERROR("Failed to disable display: %d\n", ret); > + > + /* Make sure we can restart with enabled connector next time */ > + pipeline->conn_connected = true; > + > + /* release stalled event if any */ > + send_pending_event(pipeline); > +} > + > +void xen_drm_front_kms_on_frame_done( > + struct xen_drm_front_drm_pipeline *pipeline, > + uint64_t fb_cookie) > +{ > + /* > + * This runs in interrupt context, e.g. under > + * drm_info->front_info->io_lock, so we cannot call _sync version > + * to cancel the work > + */ > + cancel_delayed_work(&pipeline->pflip_to_worker); > + > + send_pending_event(pipeline); > +} > + > +static void pflip_to_worker(struct work_struct *work) > +{ > + struct delayed_work *delayed_work = to_delayed_work(work); > + struct xen_drm_front_drm_pipeline *pipeline = > + container_of(delayed_work, > + struct xen_drm_front_drm_pipeline, > + pflip_to_worker); > + > + DRM_ERROR("Frame done timed-out, releasing"); > + send_pending_event(pipeline); > +} > + > +static bool display_send_page_flip(struct drm_simple_display_pipe *pipe, > + struct drm_plane_state *old_plane_state) > +{ > + struct drm_plane_state *plane_state = drm_atomic_get_new_plane_state( > + old_plane_state->state, &pipe->plane); > + > + /* > + * If old_plane_state->fb is NULL and plane_state->fb is not, > + * then this is an atomic commit which will enable display. > + * If old_plane_state->fb is not NULL and plane_state->fb is, > + * then this is an atomic commit which will disable display. > + * Ignore these and do not send page flip as this framebuffer will be > + * sent to the backend as a part of display_set_config call. > + */ > + if (old_plane_state->fb && plane_state->fb) { > + struct xen_drm_front_drm_pipeline *pipeline = > + to_xen_drm_pipeline(pipe); > + struct xen_drm_front_drm_info *drm_info = pipeline->drm_info; > + int ret; > + > + schedule_delayed_work(&pipeline->pflip_to_worker, > + msecs_to_jiffies(FRAME_DONE_TO_MS)); > + > + ret = xen_drm_front_page_flip(drm_info->front_info, > + pipeline->index, > + xen_drm_front_fb_to_cookie(plane_state->fb)); > + if (ret) { > + DRM_ERROR("Failed to send page flip request to backend: > %d\n", ret); > + > + pipeline->conn_connected = false; > + /* > + * Report the flip not handled, so pending event is > + * sent, unblocking user-space. > + */ > + return false; > + } > + /* > + * Signal that page flip was handled, pending event will be sent > + * on frame done event from the backend. > + */ > + return true; > + } > + > + return false; > +} > + > +static int display_prepare_fb(struct drm_simple_display_pipe *pipe, > + struct drm_plane_state *plane_state) > +{ > + return drm_gem_fb_prepare_fb(&pipe->plane, plane_state); > +} > + > +static void display_update(struct drm_simple_display_pipe *pipe, > + struct drm_plane_state *old_plane_state) > +{ > + struct xen_drm_front_drm_pipeline *pipeline = > + to_xen_drm_pipeline(pipe); > + struct drm_crtc *crtc = &pipe->crtc; > + struct drm_pending_vblank_event *event; > + int idx; > + > + event = crtc->state->event; > + if (event) { > + struct drm_device *dev = crtc->dev; > + unsigned long flags; > + > + WARN_ON(pipeline->pending_event); > + > + spin_lock_irqsave(&dev->event_lock, flags); > + crtc->state->event = NULL; > + > + pipeline->pending_event = event; > + spin_unlock_irqrestore(&dev->event_lock, flags); > + > + } > + > + if (!drm_dev_enter(pipe->crtc.dev, &idx)) { > + send_pending_event(pipeline); > + return; > + } > + > + /* > + * Send page flip request to the backend *after* we have event cached > + * above, so on page flip done event from the backend we can > + * deliver it and there is no race condition between this code and > + * event from the backend. > + * If this is not a page flip, e.g. no flip done event from the backend > + * is expected, then send now. > + */ > + if (!display_send_page_flip(pipe, old_plane_state)) > + send_pending_event(pipeline); > + > + drm_dev_exit(idx); > +} > + > +enum drm_mode_status display_mode_valid(struct drm_crtc *crtc, > + const struct drm_display_mode *mode) > +{ > + struct xen_drm_front_drm_pipeline *pipeline = > + container_of(crtc, > + struct xen_drm_front_drm_pipeline, > + pipe.crtc); > + > + if (mode->hdisplay != pipeline->width) > + return MODE_ERROR; > + > + if (mode->vdisplay != pipeline->height) > + return MODE_ERROR; > + > + return MODE_OK; > +} > + > +static const struct drm_simple_display_pipe_funcs display_funcs = { > + .mode_valid = display_mode_valid, > + .enable = display_enable, > + .disable = display_disable, > + .prepare_fb = display_prepare_fb, > + .update = display_update, > +}; > + > +static int display_pipe_init(struct xen_drm_front_drm_info *drm_info, > + int index, struct xen_drm_front_cfg_connector *cfg, > + struct xen_drm_front_drm_pipeline *pipeline) > +{ > + struct drm_device *dev = drm_info->drm_dev; > + const uint32_t *formats; > + int format_count; > + int ret; > + > + pipeline->drm_info = drm_info; > + pipeline->index = index; > + pipeline->height = cfg->height; > + pipeline->width = cfg->width; > + > + INIT_DELAYED_WORK(&pipeline->pflip_to_worker, pflip_to_worker); > + > + ret = xen_drm_front_conn_init(drm_info, &pipeline->conn); > + if (ret) > + return ret; > + > + formats = xen_drm_front_conn_get_formats(&format_count); > + > + return drm_simple_display_pipe_init(dev, &pipeline->pipe, > + &display_funcs, formats, format_count, > + NULL, &pipeline->conn); > +} > + > +int xen_drm_front_kms_init(struct xen_drm_front_drm_info *drm_info) > +{ > + struct drm_device *dev = drm_info->drm_dev; > + int i, ret; > + > + drm_mode_config_init(dev); > + > + dev->mode_config.min_width = 0; > + dev->mode_config.min_height = 0; > + dev->mode_config.max_width = 4095; > + dev->mode_config.max_height = 2047; > + dev->mode_config.funcs = &mode_config_funcs; > + > + for (i = 0; i < drm_info->front_info->cfg.num_connectors; i++) { > + struct xen_drm_front_cfg_connector *cfg = > + &drm_info->front_info->cfg.connectors[i]; > + struct xen_drm_front_drm_pipeline *pipeline = > + &drm_info->pipeline[i]; > + > + ret = display_pipe_init(drm_info, i, cfg, pipeline); > + if (ret) { > + drm_mode_config_cleanup(dev); > + return ret; > + } > + } > + > + drm_mode_config_reset(dev); > + drm_kms_helper_poll_init(dev); > + return 0; > +} > + > +void xen_drm_front_kms_fini(struct xen_drm_front_drm_info *drm_info) > +{ > + int i; > + > + for (i = 0; i < drm_info->front_info->cfg.num_connectors; i++) { > + struct xen_drm_front_drm_pipeline *pipeline = > + &drm_info->pipeline[i]; > + > + cancel_delayed_work_sync(&pipeline->pflip_to_worker); > + > + send_pending_event(pipeline); > + } > +} > diff --git a/drivers/gpu/drm/xen/xen_drm_front_kms.h > b/drivers/gpu/drm/xen/xen_drm_front_kms.h > new file mode 100644 > index 000000000000..1c3a64c36dbb > --- /dev/null > +++ b/drivers/gpu/drm/xen/xen_drm_front_kms.h > @@ -0,0 +1,27 @@ > +/* SPDX-License-Identifier: GPL-2.0 OR MIT */ > + > +/* > + * Xen para-virtual DRM device > + * > + * Copyright (C) 2016-2018 EPAM Systems Inc. > + * > + * Author: Oleksandr Andrushchenko <oleksandr_andrushchenko@xxxxxxxx> > + */ > + > +#ifndef __XEN_DRM_FRONT_KMS_H_ > +#define __XEN_DRM_FRONT_KMS_H_ > + > +#include <linux/types.h> > + > +struct xen_drm_front_drm_info; > +struct xen_drm_front_drm_pipeline; > + > +int xen_drm_front_kms_init(struct xen_drm_front_drm_info *drm_info); > + > +void xen_drm_front_kms_fini(struct xen_drm_front_drm_info *drm_info); > + > +void xen_drm_front_kms_on_frame_done( > + struct xen_drm_front_drm_pipeline *pipeline, > + uint64_t fb_cookie); > + > +#endif /* __XEN_DRM_FRONT_KMS_H_ */ > diff --git a/drivers/gpu/drm/xen/xen_drm_front_shbuf.c > b/drivers/gpu/drm/xen/xen_drm_front_shbuf.c > new file mode 100644 > index 000000000000..0fde2d8f7706 > --- /dev/null > +++ b/drivers/gpu/drm/xen/xen_drm_front_shbuf.c > @@ -0,0 +1,432 @@ > +// SPDX-License-Identifier: GPL-2.0 OR MIT > + > +/* > + * Xen para-virtual DRM device > + * > + * Copyright (C) 2016-2018 EPAM Systems Inc. > + * > + * Author: Oleksandr Andrushchenko <oleksandr_andrushchenko@xxxxxxxx> > + */ > + > +#include <drm/drmP.h> > + > +#if defined(CONFIG_X86) > +#include <drm/drm_cache.h> > +#endif > +#include <linux/errno.h> > +#include <linux/mm.h> > + > +#include <asm/xen/hypervisor.h> > +#include <xen/balloon.h> > +#include <xen/xen.h> > +#include <xen/xenbus.h> > +#include <xen/interface/io/ring.h> > +#include <xen/interface/io/displif.h> > + > +#include "xen_drm_front.h" > +#include "xen_drm_front_shbuf.h" > + > +struct xen_drm_front_shbuf_ops { > + /* > + * Calculate number of grefs required to handle this buffer, > + * e.g. if grefs are required for page directory only or the buffer > + * pages as well. > + */ > + void (*calc_num_grefs)(struct xen_drm_front_shbuf *buf); > + /* Fill page directory according to para-virtual display protocol. */ > + void (*fill_page_dir)(struct xen_drm_front_shbuf *buf); > + /* Claim grant references for the pages of the buffer. */ > + int (*grant_refs_for_buffer)(struct xen_drm_front_shbuf *buf, > + grant_ref_t *priv_gref_head, int gref_idx); > + /* Map grant references of the buffer. */ > + int (*map)(struct xen_drm_front_shbuf *buf); > + /* Unmap grant references of the buffer. */ > + int (*unmap)(struct xen_drm_front_shbuf *buf); > +}; > + > +grant_ref_t xen_drm_front_shbuf_get_dir_start(struct xen_drm_front_shbuf > *buf) > +{ > + if (!buf->grefs) > + return GRANT_INVALID_REF; > + > + return buf->grefs[0]; > +} > + > +int xen_drm_front_shbuf_map(struct xen_drm_front_shbuf *buf) > +{ > + if (buf->ops->map) > + return buf->ops->map(buf); > + > + /* no need to map own grant references */ > + return 0; > +} > + > +int xen_drm_front_shbuf_unmap(struct xen_drm_front_shbuf *buf) > +{ > + if (buf->ops->unmap) > + return buf->ops->unmap(buf); > + > + /* no need to unmap own grant references */ > + return 0; > +} > + > +void xen_drm_front_shbuf_flush(struct xen_drm_front_shbuf *buf) > +{ > +#if defined(CONFIG_X86) > + drm_clflush_pages(buf->pages, buf->num_pages); > +#endif > +} > + > +void xen_drm_front_shbuf_free(struct xen_drm_front_shbuf *buf) > +{ > + if (buf->grefs) { > + int i; > + > + for (i = 0; i < buf->num_grefs; i++) > + if (buf->grefs[i] != GRANT_INVALID_REF) > + gnttab_end_foreign_access(buf->grefs[i], > + 0, 0UL); > + } > + kfree(buf->grefs); > + kfree(buf->directory); > + if (buf->sgt) { > + sg_free_table(buf->sgt); > + kvfree(buf->pages); > + } > + kfree(buf); > +} > + > +/* > + * number of grefs a page can hold with respect to the > + * struct xendispl_page_directory header > + */ > +#define XEN_DRM_NUM_GREFS_PER_PAGE ((PAGE_SIZE - \ > + offsetof(struct xendispl_page_directory, gref)) / \ > + sizeof(grant_ref_t)) > + > +static int get_num_pages_dir(struct xen_drm_front_shbuf *buf) > +{ > + /* number of pages the page directory consumes itself */ > + return DIV_ROUND_UP(buf->num_pages, XEN_DRM_NUM_GREFS_PER_PAGE); > +} > + > +static void backend_calc_num_grefs(struct xen_drm_front_shbuf *buf) > +{ > + /* only for pages the page directory consumes itself */ > + buf->num_grefs = get_num_pages_dir(buf); > +} > + > +static void guest_calc_num_grefs(struct xen_drm_front_shbuf *buf) > +{ > + /* > + * number of pages the page directory consumes itself > + * plus grefs for the buffer pages > + */ > + buf->num_grefs = get_num_pages_dir(buf) + buf->num_pages; > +} > + > +#define xen_page_to_vaddr(page) \ > + ((phys_addr_t)pfn_to_kaddr(page_to_xen_pfn(page))) > + > +static int backend_unmap(struct xen_drm_front_shbuf *buf) > +{ > + struct gnttab_unmap_grant_ref *unmap_ops; > + int i, ret; > + > + if (!buf->pages || !buf->backend_map_handles || !buf->grefs) > + return 0; > + > + unmap_ops = kcalloc(buf->num_pages, sizeof(*unmap_ops), > + GFP_KERNEL); > + if (!unmap_ops) { > + DRM_ERROR("Failed to get memory while unmapping\n"); > + return -ENOMEM; > + } > + > + for (i = 0; i < buf->num_pages; i++) { > + phys_addr_t addr; > + > + addr = xen_page_to_vaddr(buf->pages[i]); > + gnttab_set_unmap_op(&unmap_ops[i], addr, GNTMAP_host_map, > + buf->backend_map_handles[i]); > + } > + > + ret = gnttab_unmap_refs(unmap_ops, NULL, buf->pages, > + buf->num_pages); > + > + for (i = 0; i < buf->num_pages; i++) { > + if (unlikely(unmap_ops[i].status != GNTST_okay)) > + DRM_ERROR("Failed to unmap page %d: %d\n", > + i, unmap_ops[i].status); > + } > + > + if (ret) > + DRM_ERROR("Failed to unmap grant references, ret %d", ret); > + > + kfree(unmap_ops); > + kfree(buf->backend_map_handles); > + buf->backend_map_handles = NULL; > + return ret; > +} > + > +static int backend_map(struct xen_drm_front_shbuf *buf) > +{ > + struct gnttab_map_grant_ref *map_ops = NULL; > + unsigned char *ptr; > + int ret, cur_gref, cur_dir_page, cur_page, grefs_left; > + > + map_ops = kcalloc(buf->num_pages, sizeof(*map_ops), GFP_KERNEL); > + if (!map_ops) > + return -ENOMEM; > + > + buf->backend_map_handles = kcalloc(buf->num_pages, > + sizeof(*buf->backend_map_handles), GFP_KERNEL); > + if (!buf->backend_map_handles) { > + kfree(map_ops); > + return -ENOMEM; > + } > + > + /* > + * read page directory to get grefs from the backend: for external > + * buffer we only allocate buf->grefs for the page directory, > + * so buf->num_grefs has number of pages in the page directory itself > + */ > + ptr = buf->directory; > + grefs_left = buf->num_pages; > + cur_page = 0; > + for (cur_dir_page = 0; cur_dir_page < buf->num_grefs; cur_dir_page++) { > + struct xendispl_page_directory *page_dir = > + (struct xendispl_page_directory *)ptr; > + int to_copy = XEN_DRM_NUM_GREFS_PER_PAGE; > + > + if (to_copy > grefs_left) > + to_copy = grefs_left; > + > + for (cur_gref = 0; cur_gref < to_copy; cur_gref++) { > + phys_addr_t addr; > + > + addr = xen_page_to_vaddr(buf->pages[cur_page]); > + gnttab_set_map_op(&map_ops[cur_page], addr, > + GNTMAP_host_map, > + page_dir->gref[cur_gref], > + buf->xb_dev->otherend_id); > + cur_page++; > + } > + > + grefs_left -= to_copy; > + ptr += PAGE_SIZE; > + } > + ret = gnttab_map_refs(map_ops, NULL, buf->pages, buf->num_pages); > + > + /* save handles even if error, so we can unmap */ > + for (cur_page = 0; cur_page < buf->num_pages; cur_page++) { > + buf->backend_map_handles[cur_page] = map_ops[cur_page].handle; > + if (unlikely(map_ops[cur_page].status != GNTST_okay)) > + DRM_ERROR("Failed to map page %d: %d\n", > + cur_page, map_ops[cur_page].status); > + } > + > + if (ret) { > + DRM_ERROR("Failed to map grant references, ret %d", ret); > + backend_unmap(buf); > + } > + > + kfree(map_ops); > + return ret; > +} > + > +static void backend_fill_page_dir(struct xen_drm_front_shbuf *buf) > +{ > + struct xendispl_page_directory *page_dir; > + unsigned char *ptr; > + int i, num_pages_dir; > + > + ptr = buf->directory; > + num_pages_dir = get_num_pages_dir(buf); > + > + /* fill only grefs for the page directory itself */ > + for (i = 0; i < num_pages_dir - 1; i++) { > + page_dir = (struct xendispl_page_directory *)ptr; > + > + page_dir->gref_dir_next_page = buf->grefs[i + 1]; > + ptr += PAGE_SIZE; > + } > + /* last page must say there is no more pages */ > + page_dir = (struct xendispl_page_directory *)ptr; > + page_dir->gref_dir_next_page = GRANT_INVALID_REF; > +} > + > +static void guest_fill_page_dir(struct xen_drm_front_shbuf *buf) > +{ > + unsigned char *ptr; > + int cur_gref, grefs_left, to_copy, i, num_pages_dir; > + > + ptr = buf->directory; > + num_pages_dir = get_num_pages_dir(buf); > + > + /* > + * while copying, skip grefs at start, they are for pages > + * granted for the page directory itself > + */ > + cur_gref = num_pages_dir; > + grefs_left = buf->num_pages; > + for (i = 0; i < num_pages_dir; i++) { > + struct xendispl_page_directory *page_dir = > + (struct xendispl_page_directory *)ptr; > + > + if (grefs_left <= XEN_DRM_NUM_GREFS_PER_PAGE) { > + to_copy = grefs_left; > + page_dir->gref_dir_next_page = GRANT_INVALID_REF; > + } else { > + to_copy = XEN_DRM_NUM_GREFS_PER_PAGE; > + page_dir->gref_dir_next_page = buf->grefs[i + 1]; > + } > + memcpy(&page_dir->gref, &buf->grefs[cur_gref], > + to_copy * sizeof(grant_ref_t)); > + ptr += PAGE_SIZE; > + grefs_left -= to_copy; > + cur_gref += to_copy; > + } > +} > + > +static int guest_grant_refs_for_buffer(struct xen_drm_front_shbuf *buf, > + grant_ref_t *priv_gref_head, int gref_idx) > +{ > + int i, cur_ref, otherend_id; > + > + otherend_id = buf->xb_dev->otherend_id; > + for (i = 0; i < buf->num_pages; i++) { > + cur_ref = gnttab_claim_grant_reference(priv_gref_head); > + if (cur_ref < 0) > + return cur_ref; > + gnttab_grant_foreign_access_ref(cur_ref, otherend_id, > + xen_page_to_gfn(buf->pages[i]), 0); > + buf->grefs[gref_idx++] = cur_ref; > + } > + return 0; > +} > + > +static int grant_references(struct xen_drm_front_shbuf *buf) > +{ > + grant_ref_t priv_gref_head; > + int ret, i, j, cur_ref; > + int otherend_id, num_pages_dir; > + > + ret = gnttab_alloc_grant_references(buf->num_grefs, &priv_gref_head); > + if (ret < 0) { > + DRM_ERROR("Cannot allocate grant references\n"); > + return ret; > + } > + otherend_id = buf->xb_dev->otherend_id; > + j = 0; > + num_pages_dir = get_num_pages_dir(buf); > + for (i = 0; i < num_pages_dir; i++) { > + unsigned long frame; > + > + cur_ref = gnttab_claim_grant_reference(&priv_gref_head); > + if (cur_ref < 0) > + return cur_ref; > + > + frame = xen_page_to_gfn(virt_to_page(buf->directory + > + PAGE_SIZE * i)); > + gnttab_grant_foreign_access_ref(cur_ref, otherend_id, > + frame, 0); > + buf->grefs[j++] = cur_ref; > + } > + > + if (buf->ops->grant_refs_for_buffer) { > + ret = buf->ops->grant_refs_for_buffer(buf, &priv_gref_head, j); > + if (ret) > + return ret; > + } > + > + gnttab_free_grant_references(priv_gref_head); > + return 0; > +} > + > +static int alloc_storage(struct xen_drm_front_shbuf *buf) > +{ > + if (buf->sgt) { > + buf->pages = kvmalloc_array(buf->num_pages, > + sizeof(struct page *), GFP_KERNEL); > + if (!buf->pages) > + return -ENOMEM; > + > + if (drm_prime_sg_to_page_addr_arrays(buf->sgt, buf->pages, > + NULL, buf->num_pages) < 0) > + return -EINVAL; > + } > + > + buf->grefs = kcalloc(buf->num_grefs, sizeof(*buf->grefs), GFP_KERNEL); > + if (!buf->grefs) > + return -ENOMEM; > + > + buf->directory = kcalloc(get_num_pages_dir(buf), PAGE_SIZE, GFP_KERNEL); > + if (!buf->directory) > + return -ENOMEM; > + > + return 0; > +} > + > +/* > + * For be allocated buffers we don't need grant_refs_for_buffer as those > + * grant references are allocated at backend side > + */ > +static const struct xen_drm_front_shbuf_ops backend_ops = { > + .calc_num_grefs = backend_calc_num_grefs, > + .fill_page_dir = backend_fill_page_dir, > + .map = backend_map, > + .unmap = backend_unmap > +}; > + > +/* For locally granted references we do not need to map/unmap the references > */ > +static const struct xen_drm_front_shbuf_ops local_ops = { > + .calc_num_grefs = guest_calc_num_grefs, > + .fill_page_dir = guest_fill_page_dir, > + .grant_refs_for_buffer = guest_grant_refs_for_buffer, > +}; > + > +struct xen_drm_front_shbuf *xen_drm_front_shbuf_alloc( > + struct xen_drm_front_shbuf_cfg *cfg) > +{ > + struct xen_drm_front_shbuf *buf; > + int ret; > + > + /* either pages or sgt, not both */ > + if (unlikely(cfg->pages && cfg->sgt)) { > + DRM_ERROR("Cannot handle buffer allocation with both pages and > sg table provided\n"); > + return NULL; > + } > + > + buf = kzalloc(sizeof(*buf), GFP_KERNEL); > + if (!buf) > + return NULL; > + > + if (cfg->be_alloc) > + buf->ops = &backend_ops; > + else > + buf->ops = &local_ops; > + > + buf->xb_dev = cfg->xb_dev; > + buf->num_pages = DIV_ROUND_UP(cfg->size, PAGE_SIZE); > + buf->sgt = cfg->sgt; > + buf->pages = cfg->pages; > + > + buf->ops->calc_num_grefs(buf); > + > + ret = alloc_storage(buf); > + if (ret) > + goto fail; > + > + ret = grant_references(buf); > + if (ret) > + goto fail; > + > + buf->ops->fill_page_dir(buf); > + > + return buf; > + > +fail: > + xen_drm_front_shbuf_free(buf); > + return ERR_PTR(ret); > +} > diff --git a/drivers/gpu/drm/xen/xen_drm_front_shbuf.h > b/drivers/gpu/drm/xen/xen_drm_front_shbuf.h > new file mode 100644 > index 000000000000..6c4fbc68f328 > --- /dev/null > +++ b/drivers/gpu/drm/xen/xen_drm_front_shbuf.h > @@ -0,0 +1,72 @@ > +/* SPDX-License-Identifier: GPL-2.0 OR MIT */ > + > +/* > + * Xen para-virtual DRM device > + * > + * Copyright (C) 2016-2018 EPAM Systems Inc. > + * > + * Author: Oleksandr Andrushchenko <oleksandr_andrushchenko@xxxxxxxx> > + */ > + > +#ifndef __XEN_DRM_FRONT_SHBUF_H_ > +#define __XEN_DRM_FRONT_SHBUF_H_ > + > +#include <linux/kernel.h> > +#include <linux/scatterlist.h> > + > +#include <xen/grant_table.h> > + > +struct xen_drm_front_shbuf { > + /* > + * number of references granted for the backend use: > + * - for allocated/imported dma-buf's this holds number of grant > + * references for the page directory and pages of the buffer > + * - for the buffer provided by the backend this holds number of > + * grant references for the page directory as grant references for > + * the buffer will be provided by the backend > + */ > + int num_grefs; > + grant_ref_t *grefs; > + unsigned char *directory; > + > + /* > + * there are 2 ways to provide backing storage for this shared buffer: > + * either pages or sgt. if buffer created from sgt then we own > + * the pages and must free those ourselves on closure > + */ > + int num_pages; > + struct page **pages; > + > + struct sg_table *sgt; > + > + struct xenbus_device *xb_dev; > + > + /* these are the ops used internally depending on be_alloc mode */ > + const struct xen_drm_front_shbuf_ops *ops; > + > + /* Xen map handles for the buffer allocated by the backend */ > + grant_handle_t *backend_map_handles; > +}; > + > +struct xen_drm_front_shbuf_cfg { > + struct xenbus_device *xb_dev; > + size_t size; > + struct page **pages; > + struct sg_table *sgt; > + bool be_alloc; > +}; > + > +struct xen_drm_front_shbuf *xen_drm_front_shbuf_alloc( > + struct xen_drm_front_shbuf_cfg *cfg); > + > +grant_ref_t xen_drm_front_shbuf_get_dir_start(struct xen_drm_front_shbuf > *buf); > + > +int xen_drm_front_shbuf_map(struct xen_drm_front_shbuf *buf); > + > +int xen_drm_front_shbuf_unmap(struct xen_drm_front_shbuf *buf); > + > +void xen_drm_front_shbuf_flush(struct xen_drm_front_shbuf *buf); > + > +void xen_drm_front_shbuf_free(struct xen_drm_front_shbuf *buf); > + > +#endif /* __XEN_DRM_FRONT_SHBUF_H_ */ > -- > 2.7.4 > > _______________________________________________ > dri-devel mailing list > dri-devel@xxxxxxxxxxxxxxxxxxxxx > https://lists.freedesktop.org/mailman/listinfo/dri-devel -- Daniel Vetter Software Engineer, Intel Corporation http://blog.ffwll.ch _______________________________________________ Xen-devel mailing list Xen-devel@xxxxxxxxxxxxxxxxxxxx https://lists.xenproject.org/mailman/listinfo/xen-devel

©2013 Xen Project, A Linux Foundation Collaborative Project. All Rights Reserved.
Linux Foundation is a registered trademark of The Linux Foundation.
Xen Project is a trademark of The Linux Foundation.

Re: [Xen-devel] [PATCH v4 2/2] drm/xen-front: Add support for Xen PV display frontend