[Xen-devel] [PATCH v2] xen: Stop abusing DT of_dma_configure API

[Rob Herring <robh@xxxxxxxxxx>]

As the removed comments say, these aren't DT based devices.
of_dma_configure() is going to stop allowing a NULL DT node and calling
it will no longer work.

The comment is also now out of date as of commit 9ab91e7c5c51 ("arm64:
default to the direct mapping in get_arch_dma_ops"). Direct mapping
is now the default rather than dma_dummy_ops.

According to Stefano and Oleksandr, the only other part needed is
setting the DMA masks and there's no reason to restrict the masks to
32-bits. So set the masks to 64 bits.

Cc: Robin Murphy <robin.murphy@xxxxxxx>
Cc: Julien Grall <julien.grall@xxxxxxx>
Cc: Nicolas Saenz Julienne <nsaenzjulienne@xxxxxxx>
Cc: Oleksandr Andrushchenko <oleksandr_andrushchenko@xxxxxxxx>
Cc: Boris Ostrovsky <boris.ostrovsky@xxxxxxxxxx>
Cc: Juergen Gross <jgross@xxxxxxxx>
Cc: Stefano Stabellini <sstabellini@xxxxxxxxxx>
Cc: Christoph Hellwig <hch@xxxxxx>
Cc: xen-devel@xxxxxxxxxxxxxxxxxxxx
Signed-off-by: Rob Herring <robh@xxxxxxxxxx>
---
v2:
 - Setup dma masks
 - Also fix xen_drm_front.c
 
This can now be applied to the Xen tree independent of the coming
of_dma_configure() changes.

Rob

 drivers/gpu/drm/xen/xen_drm_front.c | 12 ++----------
 drivers/xen/gntdev.c                | 13 ++-----------
 2 files changed, 4 insertions(+), 21 deletions(-)

diff --git a/drivers/gpu/drm/xen/xen_drm_front.c 
b/drivers/gpu/drm/xen/xen_drm_front.c
index ba1828acd8c9..4be49c1aef51 100644
--- a/drivers/gpu/drm/xen/xen_drm_front.c
+++ b/drivers/gpu/drm/xen/xen_drm_front.c
@@ -718,17 +718,9 @@ static int xen_drv_probe(struct xenbus_device *xb_dev,
        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->coherent_dma_mask = DMA_BIT_MASK(32);
-       ret = of_dma_configure(dev, NULL, true);
+       ret = dma_coerce_mask_and_coherent(dev, DMA_BIT_MASK(64));
        if (ret < 0) {
-               DRM_ERROR("Cannot setup DMA ops, ret %d", ret);
+               DRM_ERROR("Cannot setup DMA mask, ret %d", ret);
                return ret;
        }
 
diff --git a/drivers/xen/gntdev.c b/drivers/xen/gntdev.c
index a446a7221e13..81401f386c9c 100644
--- a/drivers/xen/gntdev.c
+++ b/drivers/xen/gntdev.c
@@ -22,6 +22,7 @@
 
 #define pr_fmt(fmt) "xen:" KBUILD_MODNAME ": " fmt
 
+#include <linux/dma-mapping.h>
 #include <linux/module.h>
 #include <linux/kernel.h>
 #include <linux/init.h>
@@ -34,9 +35,6 @@
 #include <linux/slab.h>
 #include <linux/highmem.h>
 #include <linux/refcount.h>
-#ifdef CONFIG_XEN_GRANT_DMA_ALLOC
-#include <linux/of_device.h>
-#endif
 
 #include <xen/xen.h>
 #include <xen/grant_table.h>
@@ -625,14 +623,7 @@ static int gntdev_open(struct inode *inode, struct file 
*flip)
        flip->private_data = priv;
 #ifdef CONFIG_XEN_GRANT_DMA_ALLOC
        priv->dma_dev = gntdev_miscdev.this_device;
-
-       /*
-        * 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.
-        * Fix this by calling of_dma_configure() with a NULL node to set
-        * default DMA ops.
-        */
-       of_dma_configure(priv->dma_dev, NULL, true);
+       dma_coerce_mask_and_coherent(priv->dma_dev, DMA_BIT_MASK(64));
 #endif
        pr_debug("priv %p\n", priv);
 
-- 
2.20.1


_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxxxxxxxxx
https://lists.xenproject.org/mailman/listinfo/xen-devel