Re: [PATCH 2/4] drm/amd/amdgpu: add support for iova_to_phys to replace TTM trace

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



On 18/09/17 08:52 AM, Christian König wrote:
Am 18.09.2017 um 14:35 schrieb Tom St Denis:
Signed-off-by: Tom St Denis <tom.stdenis@xxxxxxx>
---
  drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c | 32 ++++++++++++++++++++++++++++++++
  1 file changed, 32 insertions(+)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
index 7848ffa99eb4..b4c298925e2a 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
@@ -43,6 +43,7 @@
  #include <linux/swap.h>
  #include <linux/pagemap.h>
  #include <linux/debugfs.h>
+#include <linux/iommu.h>
  #include "amdgpu.h"
  #include "amdgpu_trace.h"
  #include "bif/bif_4_1_d.h"
@@ -1810,6 +1811,36 @@ static const struct file_operations amdgpu_ttm_gtt_fops = {
  #endif
+static ssize_t amdgpu_iova_to_phys_read(struct file *f, char __user *buf,
+                   size_t size, loff_t *pos)
+{
+    struct amdgpu_device *adev = file_inode(f)->i_private;
+    int r;
+    uint64_t phys;
+
+    // always return 8 bytes
+    if (size != 8)
+        return -EINVAL;
+
+    // only accept page addresses
+    if (*pos & 0xFFF)
+        return -EINVAL;
+
+
+    phys = iommu_iova_to_phys(iommu_get_domain_for_dev(adev->dev), *pos);

Well how about adding directly read/write support for the page behind the address?

This way we won't need to fiddle with /dev/mem any more either.


Given the flak we got from requesting this from the iommu team I'm worried that might not be appreciated by the community (even though we maintain this part of the tree) and hurt our abilities to upstream.

I agree that adding a read/write method would be better though since we don't need config changes of /dev/fmem anymore.

Tom
_______________________________________________
dri-devel mailing list
dri-devel@xxxxxxxxxxxxxxxxxxxxx
https://lists.freedesktop.org/mailman/listinfo/dri-devel




[Index of Archives]     [Linux DRI Users]     [Linux Intel Graphics]     [Linux USB Devel]     [Video for Linux]     [Linux Audio Users]     [Yosemite News]     [Linux Kernel]     [Linux SCSI]     [XFree86]     [Linux USB Devel]     [Video for Linux]     [Linux Audio Users]     [Linux Kernel]     [Linux SCSI]     [XFree86]
  Powered by Linux