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drm/msm: Replace custom dumb_map_offset with generic helper

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The msm driver implements a custom dumb_map_offset callback. This
implementation acquires the msm_gem_lock, but the underlying
drm_gem_create_mmap_offset() function is already thread-safe regarding
the VMA offset manager (it acquires the mgr->vm_lock internally).

Switching to the generic drm_gem_dumb_map_offset() helper provides
several benefits:
1. Removes the unnecessary locking overhead (locking leftovers).
2. Adds a missing check to reject mapping of imported objects, which is
   invalid for dumb buffers.
3. Allows for the removal of the msm_gem_dumb_map_offset() wrapper and
   the msm_gem_mmap_offset() helper function.

The logic from msm_gem_mmap_offset() has been inlined into
msm_ioctl_gem_info() to maintain functionality without the separate
helper.

This addresses the TODO:
"Documentation/gpu/todo.rst: Remove custom dumb_map_offset implementations"

Signed-off-by: Swaraj Gaikwad <swarajgaikwad1925@gmail.com>
Patchwork: https://patchwork.freedesktop.org/patch/694727/
Message-ID: <20251215022850.12358-1-swarajgaikwad1925@gmail.com>
Signed-off-by: Rob Clark <robin.clark@oss.qualcomm.com>
This commit is contained in:
Swaraj Gaikwad
2025-12-15 02:28:50 +00:00
committed by Rob Clark
parent 5b6f6a76e0
commit 3f6cf0653f
3 changed files with 5 additions and 55 deletions
Download Patch File Download Diff File Expand all files Collapse all files

8
drivers/gpu/drm/msm/msm_drv.c
View File

@@ -588,7 +588,9 @@ static int msm_ioctl_gem_info(struct drm_device *dev, void *data,
switch (args->info) {
case MSM_INFO_GET_OFFSET:
args->value = msm_gem_mmap_offset(obj);
ret = drm_gem_create_mmap_offset(obj);
if (ret == 0)
args->value = drm_vma_node_offset_addr(&obj->vma_node);
break;
case MSM_INFO_GET_IOVA:
ret = msm_ioctl_gem_info_iova(dev, file, obj, &args->value);
@@ -836,7 +838,7 @@ static const struct drm_driver msm_driver = {
.open = msm_open,
.postclose = msm_postclose,
.dumb_create = msm_gem_dumb_create,
.dumb_map_offset = msm_gem_dumb_map_offset,
.dumb_map_offset = drm_gem_dumb_map_offset,
.gem_prime_import = msm_gem_prime_import,
.gem_prime_import_sg_table = msm_gem_prime_import_sg_table,
#ifdef CONFIG_DEBUG_FS
@@ -859,7 +861,7 @@ static const struct drm_driver msm_kms_driver = {
.open = msm_open,
.postclose = msm_postclose,
.dumb_create = msm_gem_dumb_create,
.dumb_map_offset = msm_gem_dumb_map_offset,
.dumb_map_offset = drm_gem_dumb_map_offset,
.gem_prime_import_sg_table = msm_gem_prime_import_sg_table,
#ifdef CONFIG_DEBUG_FS
.debugfs_init = msm_debugfs_init,

49
drivers/gpu/drm/msm/msm_gem.c
View File

@@ -375,34 +375,6 @@ static vm_fault_t msm_gem_fault(struct vm_fault *vmf)
return ret;
}
/** get mmap offset */
static uint64_t mmap_offset(struct drm_gem_object *obj)
{
struct drm_device *dev = obj->dev;
int ret;
msm_gem_assert_locked(obj);
/* Make it mmapable */
ret = drm_gem_create_mmap_offset(obj);
if (ret) {
DRM_DEV_ERROR(dev->dev, "could not allocate mmap offset\n");
return 0;
}
return drm_vma_node_offset_addr(&obj->vma_node);
}
uint64_t msm_gem_mmap_offset(struct drm_gem_object *obj)
{
uint64_t offset;
msm_gem_lock(obj);
offset = mmap_offset(obj);
msm_gem_unlock(obj);
return offset;
}
static struct drm_gpuva *lookup_vma(struct drm_gem_object *obj,
struct drm_gpuvm *vm)
@@ -730,27 +702,6 @@ int msm_gem_dumb_create(struct drm_file *file, struct drm_device *dev,
MSM_BO_SCANOUT | MSM_BO_WC, &args->handle, "dumb");
}
int msm_gem_dumb_map_offset(struct drm_file *file, struct drm_device *dev,
uint32_t handle, uint64_t *offset)
{
struct drm_gem_object *obj;
int ret = 0;
/* GEM does all our handle to object mapping */
obj = drm_gem_object_lookup(file, handle);
if (obj == NULL) {
ret = -ENOENT;
goto fail;
}
*offset = msm_gem_mmap_offset(obj);
drm_gem_object_put(obj);
fail:
return ret;
}
static void *get_vaddr(struct drm_gem_object *obj, unsigned madv)
{
struct msm_gem_object *msm_obj = to_msm_bo(obj);

3
drivers/gpu/drm/msm/msm_gem.h
View File

@@ -262,7 +262,6 @@ struct msm_gem_object {
void msm_gem_vma_get(struct drm_gem_object *obj);
void msm_gem_vma_put(struct drm_gem_object *obj);
uint64_t msm_gem_mmap_offset(struct drm_gem_object *obj);
int msm_gem_prot(struct drm_gem_object *obj);
int msm_gem_pin_vma_locked(struct drm_gem_object *obj, struct drm_gpuva *vma);
void msm_gem_unpin_locked(struct drm_gem_object *obj);
@@ -285,8 +284,6 @@ struct page **msm_gem_pin_pages_locked(struct drm_gem_object *obj);
void msm_gem_unpin_pages_locked(struct drm_gem_object *obj);
int msm_gem_dumb_create(struct drm_file *file, struct drm_device *dev,
struct drm_mode_create_dumb *args);
int msm_gem_dumb_map_offset(struct drm_file *file, struct drm_device *dev,
uint32_t handle, uint64_t *offset);
void *msm_gem_get_vaddr_locked(struct drm_gem_object *obj);
void *msm_gem_get_vaddr(struct drm_gem_object *obj);
void *msm_gem_get_vaddr_active(struct drm_gem_object *obj);