[PATCH v15 11/17] drm/amdgpu, arm64: untag user pointers

[Andrey Konovalov]

This patch is a part of a series that extends arm64 kernel ABI to allow to
pass tagged user pointers (with the top byte set to something else other
than 0x00) as syscall arguments.

In amdgpu_gem_userptr_ioctl() and amdgpu_amdkfd_gpuvm.c/init_user_pages()
an MMU notifier is set up with a (tagged) userspace pointer. The untagged
address should be used so that MMU notifiers for the untagged address get
correctly matched up with the right BO. This patch untag user pointers in
amdgpu_gem_userptr_ioctl() for the GEM case and in amdgpu_amdkfd_gpuvm_
alloc_memory_of_gpu() for the KFD case. This also makes sure that an
untagged pointer is passed to amdgpu_ttm_tt_get_user_pages(), which uses
it for vma lookups.

Suggested-by: Kuehling, Felix <Felix.Kuehling at amd.com>
Signed-off-by: Andrey Konovalov <andreyknvl at google.com>
---
 drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c | 2 +-
 drivers/gpu/drm/amd/amdgpu/amdgpu_gem.c          | 2 ++
 2 files changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c
index 1921dec3df7a..20cac44ed449 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c
@@ -1121,7 +1121,7 @@ int amdgpu_amdkfd_gpuvm_alloc_memory_of_gpu(
 		alloc_flags = 0;
 		if (!offset || !*offset)
 			return -EINVAL;
-		user_addr = *offset;
+		user_addr = untagged_addr(*offset);
 	} else if (flags & ALLOC_MEM_FLAGS_DOORBELL) {
 		domain = AMDGPU_GEM_DOMAIN_GTT;
 		alloc_domain = AMDGPU_GEM_DOMAIN_CPU;
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_gem.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_gem.c
index d21dd2f369da..985cb82b2aa6 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_gem.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_gem.c
@@ -286,6 +286,8 @@ int amdgpu_gem_userptr_ioctl(struct drm_device *dev, void *data,
 	uint32_t handle;
 	int r;
 
+	args->addr = untagged_addr(args->addr);
+
 	if (offset_in_page(args->addr | args->size))
 		return -EINVAL;
 
-- 
2.21.0.1020.gf2820cf01a-goog