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[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] Re: [Xen-devel] [PATCH 8/9] drm/xen-front: Implement GEM operations
On Mon, Mar 05, 2018 at 03:46:07PM +0200, Oleksandr Andrushchenko wrote: > On 03/05/2018 11:32 AM, Daniel Vetter wrote: > > On Wed, Feb 21, 2018 at 10:03:41AM +0200, Oleksandr Andrushchenko wrote: > > > From: Oleksandr Andrushchenko <oleksandr_andrushchenko@xxxxxxxx> > > > > > > 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. > > > > > > 1. Buffers allocated by the frontend driver. > > > > > > The below modes of operation are configured at compile-time via > > > frontend driver's kernel configuration. > > > > > > 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. > > > > > > 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. > > > > > > 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! Configuration options 1.1 (contiguous display buffers) and 2 > > > (backend > > > allocated buffers) are not supported at the same time. > > > > > > Signed-off-by: Oleksandr Andrushchenko <oleksandr_andrushchenko@xxxxxxxx> > > Some suggestions below for some larger cleanup work. > > -Daniel > > > > > --- > > > drivers/gpu/drm/xen/Kconfig | 13 + > > > drivers/gpu/drm/xen/Makefile | 6 + > > > drivers/gpu/drm/xen/xen_drm_front.h | 74 ++++++ > > > drivers/gpu/drm/xen/xen_drm_front_drv.c | 80 ++++++- > > > drivers/gpu/drm/xen/xen_drm_front_drv.h | 1 + > > > drivers/gpu/drm/xen/xen_drm_front_gem.c | 360 > > > ++++++++++++++++++++++++++++ > > > drivers/gpu/drm/xen/xen_drm_front_gem.h | 46 ++++ > > > drivers/gpu/drm/xen/xen_drm_front_gem_cma.c | 93 +++++++ > > > 8 files changed, 667 insertions(+), 6 deletions(-) > > > 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 > > > > > > diff --git a/drivers/gpu/drm/xen/Kconfig b/drivers/gpu/drm/xen/Kconfig > > > index 4cca160782ab..4f4abc91f3b6 100644 > > > --- a/drivers/gpu/drm/xen/Kconfig > > > +++ b/drivers/gpu/drm/xen/Kconfig > > > @@ -15,3 +15,16 @@ config DRM_XEN_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 > > > index 4fcb0da1a9c5..12376ec78fbc 100644 > > > --- a/drivers/gpu/drm/xen/Makefile > > > +++ b/drivers/gpu/drm/xen/Makefile > > > @@ -8,4 +8,10 @@ drm_xen_front-objs := xen_drm_front.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.h > > > b/drivers/gpu/drm/xen/xen_drm_front.h > > > index 9ed5bfb248d0..c6f52c892434 100644 > > > --- a/drivers/gpu/drm/xen/xen_drm_front.h > > > +++ b/drivers/gpu/drm/xen/xen_drm_front.h > > > @@ -34,6 +34,80 @@ > > > struct xen_drm_front_drm_pipeline; > > > +/* > > > + > > > ******************************************************************************* > > > + * Para-virtualized DRM/KMS 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 > > > + > > > ******************************************************************************* > > > + * 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. > > > + * > > > + > > > ******************************************************************************* > > > + * 1. Buffers allocated by the frontend driver. > > > + > > > ******************************************************************************* > > > + * > > > + * The below modes of operation are configured at compile-time via > > > + * frontend driver's kernel configuration. > > > + * > > > + * 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. > > > + * > > > + * 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. > > > + * > > > + > > > ******************************************************************************* > > > + * 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. > > > + * > > > + > > > ******************************************************************************* > > > + * Driver limitations > > > + > > > ******************************************************************************* > > > + * 1. Configuration options 1.1 (contiguous display buffers) and 2 > > > (backend > > > + * allocated buffers) are not supported at the same time. > > > + * > > > + * 2. Only primary plane without additional properties is supported. > > > + * > > > + * 3. Only one video mode supported which is configured via XenStore. > > > + * > > > + * 4. All CRTCs operate at fixed frequency of 60Hz. > > > + * > > > + > > > ******************************************************************************/ > > Since you've typed this all up, pls convert it to kernel-doc and pull it > > into a xen-front.rst driver section in Documentation/gpu/ There's a few > > examples for i915 and vc4 already. > Do you mean to move or to keep in the driver and add in the > Documentation? I would prefer to move to have the description > at single place. Keep it where it is, but reformat as a correct kerneldoc (it's RST format) and pull it in as a DOC: section. See https://dri.freedesktop.org/docs/drm/doc-guide/kernel-doc.html and the other sections in that chapter. > > > > > + > > > struct xen_drm_front_ops { > > > int (*mode_set)(struct xen_drm_front_drm_pipeline *pipeline, > > > uint32_t x, uint32_t y, uint32_t width, > > > uint32_t height, > > > diff --git a/drivers/gpu/drm/xen/xen_drm_front_drv.c > > > b/drivers/gpu/drm/xen/xen_drm_front_drv.c > > > index e8862d26ba27..35e7e9cda9d1 100644 > > > --- a/drivers/gpu/drm/xen/xen_drm_front_drv.c > > > +++ b/drivers/gpu/drm/xen/xen_drm_front_drv.c > > > @@ -23,12 +23,58 @@ > > > #include "xen_drm_front.h" > > > #include "xen_drm_front_cfg.h" > > > #include "xen_drm_front_drv.h" > > > +#include "xen_drm_front_gem.h" > > > #include "xen_drm_front_kms.h" > > > static int dumb_create(struct drm_file *filp, > > > struct drm_device *dev, struct drm_mode_create_dumb > > > *args) > > > { > > > - return -EINVAL; > > > + struct xen_drm_front_drm_info *drm_info = dev->dev_private; > > > + struct drm_gem_object *obj; > > > + int ret; > > > + > > > + ret = drm_info->gem_ops->dumb_create(filp, dev, args); > > > + if (ret) > > > + goto fail; > > > + > > > + obj = drm_gem_object_lookup(filp, args->handle); > > > + if (!obj) { > > > + ret = -ENOENT; > > > + goto fail_destroy; > > > + } > > > + > > > + drm_gem_object_unreference_unlocked(obj); > > > + > > > + /* > > > + * 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 > > > + */ > > My recommendation is to use an sg table for everything if you deal with > > mixed objects (CMA, special blocks 1:1 mapped from host, normal pages). > > That avoids the constant get_pages vs. get_sgt differences. For examples > > see how e.g. i915 handles the various gem object backends. > Indeed, I tried to do that this way before, e.g. have all sgt based. > But at the end of the day Xen shared buffer code in the driver works > with pages (Xen API is page based there), so sgt then will anyway need > to be converted into page array. > For that reason I prefer to work with pages from the beginning, not sgt. > As to constant get_pages etc. - this is the only expected place in the > driver for that, so the _from_sgt/_from_pages API is only used here. Yeah was just a suggestion to simplify the code. But if you have to deal with both, there's not much point. > > > > > > + if (drm_info->gem_ops->get_pages(obj)) > > > + ret = drm_info->front_ops->dbuf_create_from_pages( > > > + drm_info->front_info, > > > + xen_drm_front_dbuf_to_cookie(obj), > > > + args->width, args->height, args->bpp, > > > + args->size, > > > + drm_info->gem_ops->get_pages(obj)); > > > + else > > > + ret = drm_info->front_ops->dbuf_create_from_sgt( > > > + drm_info->front_info, > > > + xen_drm_front_dbuf_to_cookie(obj), > > > + args->width, args->height, args->bpp, > > > + args->size, > > > + drm_info->gem_ops->prime_get_sg_table(obj)); > > > + if (ret) > > > + goto fail_destroy; > > > + > > > + return 0; > > > + > > > +fail_destroy: > > > + drm_gem_dumb_destroy(filp, dev, args->handle); > > > +fail: > > > + DRM_ERROR("Failed to create dumb buffer: %d\n", ret); > > > + return ret; > > > } > > > static void free_object(struct drm_gem_object *obj) > > > @@ -37,6 +83,7 @@ static void free_object(struct drm_gem_object *obj) > > > drm_info->front_ops->dbuf_destroy(drm_info->front_info, > > > xen_drm_front_dbuf_to_cookie(obj)); > > > + drm_info->gem_ops->free_object_unlocked(obj); > > > } > > > static void on_frame_done(struct platform_device *pdev, > > > @@ -60,32 +107,52 @@ static void lastclose(struct drm_device *dev) > > > static int gem_mmap(struct file *filp, struct vm_area_struct *vma) > > > { > > > - return -EINVAL; > > > + struct drm_file *file_priv = filp->private_data; > > > + struct drm_device *dev = file_priv->minor->dev; > > > + struct xen_drm_front_drm_info *drm_info = dev->dev_private; > > > + > > > + return drm_info->gem_ops->mmap(filp, vma); > > Uh, so 1 midlayer for the kms stuff and another midlayer for the gem > > stuff. That's way too much indirection. > If by KMS you mean front_ops then -1: I will remove front_ops. > As to gem_ops, please see below > > > } > > > static struct sg_table *prime_get_sg_table(struct drm_gem_object *obj) > > > { > > > - return NULL; > > > + struct xen_drm_front_drm_info *drm_info; > > > + > > > + drm_info = obj->dev->dev_private; > > > + return drm_info->gem_ops->prime_get_sg_table(obj); > > > } > > > static struct drm_gem_object *prime_import_sg_table(struct drm_device > > > *dev, > > > struct dma_buf_attachment *attach, struct sg_table *sgt) > > > { > > > - return NULL; > > > + struct xen_drm_front_drm_info *drm_info; > > > + > > > + drm_info = dev->dev_private; > > > + return drm_info->gem_ops->prime_import_sg_table(dev, attach, sgt); > > > } > > > static void *prime_vmap(struct drm_gem_object *obj) > > > { > > > - return NULL; > > > + struct xen_drm_front_drm_info *drm_info; > > > + > > > + drm_info = obj->dev->dev_private; > > > + return drm_info->gem_ops->prime_vmap(obj); > > > } > > > static void prime_vunmap(struct drm_gem_object *obj, void *vaddr) > > > { > > > + struct xen_drm_front_drm_info *drm_info; > > > + > > > + drm_info = obj->dev->dev_private; > > > + drm_info->gem_ops->prime_vunmap(obj, vaddr); > > > } > > > static int prime_mmap(struct drm_gem_object *obj, struct vm_area_struct > > > *vma) > > > { > > > - return -EINVAL; > > > + struct xen_drm_front_drm_info *drm_info; > > > + > > > + drm_info = obj->dev->dev_private; > > > + return drm_info->gem_ops->prime_mmap(obj, vma); > > > } > > > static const struct file_operations xendrm_fops = { > > > @@ -147,6 +214,7 @@ int xen_drm_front_drv_probe(struct platform_device > > > *pdev, > > > drm_info->front_ops = front_ops; > > > drm_info->front_ops->on_frame_done = on_frame_done; > > > + drm_info->gem_ops = xen_drm_front_gem_get_ops(); > > > drm_info->front_info = cfg->front_info; > > > dev = drm_dev_alloc(&xen_drm_driver, &pdev->dev); > > > diff --git a/drivers/gpu/drm/xen/xen_drm_front_drv.h > > > b/drivers/gpu/drm/xen/xen_drm_front_drv.h > > > index 563318b19f34..34228eb86255 100644 > > > --- a/drivers/gpu/drm/xen/xen_drm_front_drv.h > > > +++ b/drivers/gpu/drm/xen/xen_drm_front_drv.h > > > @@ -43,6 +43,7 @@ struct xen_drm_front_drm_pipeline { > > > struct xen_drm_front_drm_info { > > > struct xen_drm_front_info *front_info; > > > struct xen_drm_front_ops *front_ops; > > > + const struct xen_drm_front_gem_ops *gem_ops; > > > struct drm_device *drm_dev; > > > struct xen_drm_front_cfg *cfg; > > > 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..367e08f6a9ef > > > --- /dev/null > > > +++ b/drivers/gpu/drm/xen/xen_drm_front_gem.c > > > @@ -0,0 +1,360 @@ > > > +/* > > > + * Xen para-virtual DRM device > > > + * > > > + * This program is free software; you can redistribute it and/or modify > > > + * it under the terms of the GNU General Public License as published by > > > + * the Free Software Foundation; either version 2 of the License, or > > > + * (at your option) any later version. > > > + * > > > + * This program is distributed in the hope that it will be useful, > > > + * but WITHOUT ANY WARRANTY; without even the implied warranty of > > > + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the > > > + * GNU General Public License for more details. > > > + * > > > + * 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_drv.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->cfg->be_alloc) { > > > + /* > > > + * backend will allocate space for this buffer, so > > > + * only allocate array of pointers to pages > > > + */ > > > + xen_obj->be_alloc = true; > > > + ret = gem_alloc_pages_array(xen_obj, size); > > > + if (ret < 0) { > > > + gem_free_pages_array(xen_obj); > > > + goto fail; > > > + } > > > + > > > + 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); > > > + goto fail; > > > + } > > > + > > > + 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); > > > +} > > > + > > > +static struct xen_gem_object *gem_create_with_handle(struct drm_file > > > *filp, > > > + struct drm_device *dev, size_t size, uint32_t *handle) > > > +{ > > > + struct xen_gem_object *xen_obj; > > > + struct drm_gem_object *gem_obj; > > > + int ret; > > > + > > > + xen_obj = gem_create(dev, size); > > > + if (IS_ERR_OR_NULL(xen_obj)) > > > + return xen_obj; > > > + > > > + gem_obj = &xen_obj->base; > > > + ret = drm_gem_handle_create(filp, gem_obj, handle); > > > + /* handle holds the reference */ > > > + drm_gem_object_unreference_unlocked(gem_obj); > > > + if (ret < 0) > > > + return ERR_PTR(ret); > > > + > > > + return xen_obj; > > > +} > > > + > > > +static int gem_dumb_create(struct drm_file *filp, struct drm_device *dev, > > > + struct drm_mode_create_dumb *args) > > > +{ > > > + struct xen_gem_object *xen_obj; > > > + > > > + args->pitch = DIV_ROUND_UP(args->width * args->bpp, 8); > > > + args->size = args->pitch * args->height; > > > + > > > + xen_obj = gem_create_with_handle(filp, dev, args->size, &args->handle); > > > + if (IS_ERR_OR_NULL(xen_obj)) > > > + return xen_obj == NULL ? -ENOMEM : PTR_ERR(xen_obj); > > > + > > > + return 0; > > > +} > > > + > > > +static void gem_free_object(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); > > > +} > > > + > > > +static struct page **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; > > > +} > > > + > > > +static struct sg_table *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); > > > +} > > > + > > > +static struct drm_gem_object *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 = drm_info->front_ops->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; > > > +} > > > + > > > +static int 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); > > > +} > > > + > > > +static void *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)); > > > +} > > > + > > > +static void gem_prime_vunmap(struct drm_gem_object *gem_obj, void *vaddr) > > > +{ > > > + vunmap(vaddr); > > > +} > > > + > > > +static int 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); > > > +} > > > + > > > +static const struct xen_drm_front_gem_ops xen_drm_gem_ops = { > > > + .free_object_unlocked = gem_free_object, > > > + .prime_get_sg_table = gem_get_sg_table, > > > + .prime_import_sg_table = gem_import_sg_table, > > > + > > > + .prime_vmap = gem_prime_vmap, > > > + .prime_vunmap = gem_prime_vunmap, > > > + .prime_mmap = gem_prime_mmap, > > > + > > > + .dumb_create = gem_dumb_create, > > > + > > > + .mmap = gem_mmap, > > > + > > > + .get_pages = gem_get_pages, > > > +}; > > > + > > > +const struct xen_drm_front_gem_ops *xen_drm_front_gem_get_ops(void) > > > +{ > > > + return &xen_drm_gem_ops; > > > +} > > > 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..d1e1711cc3fc > > > --- /dev/null > > > +++ b/drivers/gpu/drm/xen/xen_drm_front_gem.h > > > @@ -0,0 +1,46 @@ > > > +/* > > > + * Xen para-virtual DRM device > > > + * > > > + * This program is free software; you can redistribute it and/or modify > > > + * it under the terms of the GNU General Public License as published by > > > + * the Free Software Foundation; either version 2 of the License, or > > > + * (at your option) any later version. > > > + * > > > + * This program is distributed in the hope that it will be useful, > > > + * but WITHOUT ANY WARRANTY; without even the implied warranty of > > > + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the > > > + * GNU General Public License for more details. > > > + * > > > + * 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 xen_drm_front_gem_ops { > > > + void (*free_object_unlocked)(struct drm_gem_object *obj); > > > + > > > + struct sg_table *(*prime_get_sg_table)(struct drm_gem_object *obj); > > > + struct drm_gem_object *(*prime_import_sg_table)(struct drm_device *dev, > > > + struct dma_buf_attachment *attach, > > > + struct sg_table *sgt); > > > + void *(*prime_vmap)(struct drm_gem_object *obj); > > > + void (*prime_vunmap)(struct drm_gem_object *obj, void *vaddr); > > > + int (*prime_mmap)(struct drm_gem_object *obj, > > > + struct vm_area_struct *vma); > > > + > > > + int (*dumb_create)(struct drm_file *file_priv, struct drm_device *dev, > > > + struct drm_mode_create_dumb *args); > > > + > > > + int (*mmap)(struct file *filp, struct vm_area_struct *vma); > > > + > > > + struct page **(*get_pages)(struct drm_gem_object *obj); > > > +}; > > > + > > > +const struct xen_drm_front_gem_ops *xen_drm_front_gem_get_ops(void); > > > + > > > +#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..5ffcbfa652d5 > > > --- /dev/null > > > +++ b/drivers/gpu/drm/xen/xen_drm_front_gem_cma.c > > > @@ -0,0 +1,93 @@ > > > +/* > > > + * Xen para-virtual DRM device > > > + * > > > + * This program is free software; you can redistribute it and/or modify > > > + * it under the terms of the GNU General Public License as published by > > > + * the Free Software Foundation; either version 2 of the License, or > > > + * (at your option) any later version. > > > + * > > > + * This program is distributed in the hope that it will be useful, > > > + * but WITHOUT ANY WARRANTY; without even the implied warranty of > > > + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the > > > + * GNU General Public License for more details. > > > + * > > > + * 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_drv.h" > > > +#include "xen_drm_front_gem.h" > > > + > > > +static struct drm_gem_object *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 = drm_info->front_ops->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; > > > +} > > > + > > > +static int gem_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; > > > + > > > + if (drm_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 -EINVAL; > > > + } > > > + > > > + return drm_gem_cma_dumb_create(filp, dev, args); > > > +} > > > + > > > +static struct page **gem_get_pages(struct drm_gem_object *gem_obj) > > > +{ > > > + return NULL; > > > +} > > > + > > > +static const struct xen_drm_front_gem_ops xen_drm_front_gem_cma_ops = { > > > + .free_object_unlocked = drm_gem_cma_free_object, > > > + .prime_get_sg_table = drm_gem_cma_prime_get_sg_table, > > > + .prime_import_sg_table = gem_import_sg_table, > > > + > > > + .prime_vmap = drm_gem_cma_prime_vmap, > > > + .prime_vunmap = drm_gem_cma_prime_vunmap, > > > + .prime_mmap = drm_gem_cma_prime_mmap, > > > + > > > + .dumb_create = gem_dumb_create, > > > + > > > + .mmap = drm_gem_cma_mmap, > > > + > > > + .get_pages = gem_get_pages, > > > +}; > > Again quite a midlayer you have here. Please inline this to avoid > > confusion for other people (since it looks like you only have 1 > > implementation). > There are 2 implementations depending on driver compile time options: > you can have the GEM operations implemented with DRM CMA helpers > or driver's cooked GEMs. For this reason this midlayer exists, e.g. > to eliminate the need for something like > #ifdef DRM_XEN_FRONTEND_CMA > drm_gem_cma_...() > #else > xen_drm_front_gem_...() > #endif > So, I would prefer to have ops rather then having ifdefs Ok, makes sense, but please review whether you really need all of them, since for a lot of them (all except get_pages really) we already have vfuncs. And if you only switch at compile time I think it's cleaner to simply have 2 vfunc tables for those (e.g. struct drm_driver). That avoids the indirection. Cheers, Daniel > > > > > + > > > +const struct xen_drm_front_gem_ops *xen_drm_front_gem_get_ops(void) > > > +{ > > > + return &xen_drm_front_gem_cma_ops; > > > +} > > > -- > > > 2.7.4 > > > > > > _______________________________________________ > > > dri-devel mailing list > > > dri-devel@xxxxxxxxxxxxxxxxxxxxx > > > https://lists.freedesktop.org/mailman/listinfo/dri-devel > > _______________________________________________ > 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
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