lkml.org 
[lkml]   [2022]   [Apr]   [24]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH v5 11/17] drm/shmem-helper: Take reservation lock instead of drm_gem_shmem locks
Date
Replace drm_gem_shmem locks with the reservation lock to make GEM
lockings more consistent.

Previously drm_gem_shmem_vmap() and drm_gem_shmem_get_pages() were
protected by separate locks, now it's the same lock for non-imported GEMs.
For imported GEMs with still use a separate lock in vmap/vunmap() to
avoid recursive locking of reservations, the reservation's locking isn't
needed in this case.

Suggested-by: Daniel Vetter <daniel@ffwll.ch>
Signed-off-by: Dmitry Osipenko <dmitry.osipenko@collabora.com>
---
drivers/gpu/drm/drm_gem_shmem_helper.c | 54 ++++++++++++-------
drivers/gpu/drm/lima/lima_gem.c | 8 +--
.../gpu/drm/panfrost/panfrost_gem_shrinker.c | 4 +-
drivers/gpu/drm/panfrost/panfrost_mmu.c | 15 +++---
include/drm/drm_gem_shmem_helper.h | 5 --
5 files changed, 50 insertions(+), 36 deletions(-)

diff --git a/drivers/gpu/drm/drm_gem_shmem_helper.c b/drivers/gpu/drm/drm_gem_shmem_helper.c
index 5c7a7106b41d..cc90a4c28ace 100644
--- a/drivers/gpu/drm/drm_gem_shmem_helper.c
+++ b/drivers/gpu/drm/drm_gem_shmem_helper.c
@@ -86,7 +86,6 @@ __drm_gem_shmem_create(struct drm_device *dev, size_t size, bool private)
if (ret)
goto err_release;

- mutex_init(&shmem->pages_lock);
mutex_init(&shmem->vmap_lock);
INIT_LIST_HEAD(&shmem->madv_list);

@@ -157,8 +156,6 @@ void drm_gem_shmem_free(struct drm_gem_shmem_object *shmem)
WARN_ON(shmem->pages_use_count);

drm_gem_object_release(obj);
- mutex_destroy(&shmem->pages_lock);
- mutex_destroy(&shmem->vmap_lock);
kfree(shmem);
}
EXPORT_SYMBOL_GPL(drm_gem_shmem_free);
@@ -209,11 +206,11 @@ int drm_gem_shmem_get_pages(struct drm_gem_shmem_object *shmem)

WARN_ON(shmem->base.import_attach);

- ret = mutex_lock_interruptible(&shmem->pages_lock);
+ ret = dma_resv_lock_interruptible(shmem->base.resv, NULL);
if (ret)
return ret;
ret = drm_gem_shmem_get_pages_locked(shmem);
- mutex_unlock(&shmem->pages_lock);
+ dma_resv_unlock(shmem->base.resv);

return ret;
}
@@ -248,9 +245,9 @@ static void drm_gem_shmem_put_pages_locked(struct drm_gem_shmem_object *shmem)
*/
void drm_gem_shmem_put_pages(struct drm_gem_shmem_object *shmem)
{
- mutex_lock(&shmem->pages_lock);
+ dma_resv_lock(shmem->base.resv, NULL);
drm_gem_shmem_put_pages_locked(shmem);
- mutex_unlock(&shmem->pages_lock);
+ dma_resv_unlock(shmem->base.resv);
}
EXPORT_SYMBOL(drm_gem_shmem_put_pages);

@@ -310,7 +307,7 @@ static int drm_gem_shmem_vmap_locked(struct drm_gem_shmem_object *shmem,
} else {
pgprot_t prot = PAGE_KERNEL;

- ret = drm_gem_shmem_get_pages(shmem);
+ ret = drm_gem_shmem_get_pages_locked(shmem);
if (ret)
goto err_zero_use;

@@ -358,13 +355,22 @@ static int drm_gem_shmem_vmap_locked(struct drm_gem_shmem_object *shmem,
int drm_gem_shmem_vmap(struct drm_gem_shmem_object *shmem,
struct iosys_map *map)
{
+ struct drm_gem_object *obj = &shmem->base;
int ret;

- ret = mutex_lock_interruptible(&shmem->vmap_lock);
+ if (obj->import_attach)
+ ret = mutex_lock_interruptible(&shmem->vmap_lock);
+ else
+ ret = dma_resv_lock_interruptible(shmem->base.resv, NULL);
+
if (ret)
return ret;
ret = drm_gem_shmem_vmap_locked(shmem, map);
- mutex_unlock(&shmem->vmap_lock);
+
+ if (obj->import_attach)
+ mutex_unlock(&shmem->vmap_lock);
+ else
+ dma_resv_unlock(shmem->base.resv);

return ret;
}
@@ -385,7 +391,7 @@ static void drm_gem_shmem_vunmap_locked(struct drm_gem_shmem_object *shmem,
dma_buf_vunmap(obj->import_attach->dmabuf, map);
} else {
vunmap(shmem->vaddr);
- drm_gem_shmem_put_pages(shmem);
+ drm_gem_shmem_put_pages_locked(shmem);
}

shmem->vaddr = NULL;
@@ -406,9 +412,19 @@ static void drm_gem_shmem_vunmap_locked(struct drm_gem_shmem_object *shmem,
void drm_gem_shmem_vunmap(struct drm_gem_shmem_object *shmem,
struct iosys_map *map)
{
- mutex_lock(&shmem->vmap_lock);
+ struct drm_gem_object *obj = &shmem->base;
+
+ if (obj->import_attach)
+ mutex_lock(&shmem->vmap_lock);
+ else
+ dma_resv_lock(shmem->base.resv, NULL);
+
drm_gem_shmem_vunmap_locked(shmem, map);
- mutex_unlock(&shmem->vmap_lock);
+
+ if (obj->import_attach)
+ mutex_unlock(&shmem->vmap_lock);
+ else
+ dma_resv_unlock(shmem->base.resv);
}
EXPORT_SYMBOL(drm_gem_shmem_vunmap);

@@ -442,14 +458,14 @@ drm_gem_shmem_create_with_handle(struct drm_file *file_priv,
*/
int drm_gem_shmem_madvise(struct drm_gem_shmem_object *shmem, int madv)
{
- mutex_lock(&shmem->pages_lock);
+ dma_resv_lock(shmem->base.resv, NULL);

if (shmem->madv >= 0)
shmem->madv = madv;

madv = shmem->madv;

- mutex_unlock(&shmem->pages_lock);
+ dma_resv_unlock(shmem->base.resv);

return (madv >= 0);
}
@@ -487,10 +503,10 @@ EXPORT_SYMBOL(drm_gem_shmem_purge_locked);

bool drm_gem_shmem_purge(struct drm_gem_shmem_object *shmem)
{
- if (!mutex_trylock(&shmem->pages_lock))
+ if (!dma_resv_trylock(shmem->base.resv))
return false;
drm_gem_shmem_purge_locked(shmem);
- mutex_unlock(&shmem->pages_lock);
+ dma_resv_unlock(shmem->base.resv);

return true;
}
@@ -549,7 +565,7 @@ static vm_fault_t drm_gem_shmem_fault(struct vm_fault *vmf)
/* We don't use vmf->pgoff since that has the fake offset */
page_offset = (vmf->address - vma->vm_start) >> PAGE_SHIFT;

- mutex_lock(&shmem->pages_lock);
+ dma_resv_lock(shmem->base.resv, NULL);

if (page_offset >= num_pages ||
WARN_ON_ONCE(!shmem->pages) ||
@@ -561,7 +577,7 @@ static vm_fault_t drm_gem_shmem_fault(struct vm_fault *vmf)
ret = vmf_insert_pfn(vma, vmf->address, page_to_pfn(page));
}

- mutex_unlock(&shmem->pages_lock);
+ dma_resv_unlock(shmem->base.resv);

return ret;
}
diff --git a/drivers/gpu/drm/lima/lima_gem.c b/drivers/gpu/drm/lima/lima_gem.c
index 0f1ca0b0db49..5008f0c2428f 100644
--- a/drivers/gpu/drm/lima/lima_gem.c
+++ b/drivers/gpu/drm/lima/lima_gem.c
@@ -34,7 +34,7 @@ int lima_heap_alloc(struct lima_bo *bo, struct lima_vm *vm)

new_size = min(new_size, bo->base.base.size);

- mutex_lock(&bo->base.pages_lock);
+ dma_resv_lock(bo->base.base.resv, NULL);

if (bo->base.pages) {
pages = bo->base.pages;
@@ -42,7 +42,7 @@ int lima_heap_alloc(struct lima_bo *bo, struct lima_vm *vm)
pages = kvmalloc_array(bo->base.base.size >> PAGE_SHIFT,
sizeof(*pages), GFP_KERNEL | __GFP_ZERO);
if (!pages) {
- mutex_unlock(&bo->base.pages_lock);
+ dma_resv_unlock(bo->base.base.resv);
return -ENOMEM;
}

@@ -56,13 +56,13 @@ int lima_heap_alloc(struct lima_bo *bo, struct lima_vm *vm)
struct page *page = shmem_read_mapping_page(mapping, i);

if (IS_ERR(page)) {
- mutex_unlock(&bo->base.pages_lock);
+ dma_resv_unlock(bo->base.base.resv);
return PTR_ERR(page);
}
pages[i] = page;
}

- mutex_unlock(&bo->base.pages_lock);
+ dma_resv_unlock(bo->base.base.resv);

ret = sg_alloc_table_from_pages(&sgt, pages, i, 0,
new_size, GFP_KERNEL);
diff --git a/drivers/gpu/drm/panfrost/panfrost_gem_shrinker.c b/drivers/gpu/drm/panfrost/panfrost_gem_shrinker.c
index 77e7cb6d1ae3..3bcf8c291866 100644
--- a/drivers/gpu/drm/panfrost/panfrost_gem_shrinker.c
+++ b/drivers/gpu/drm/panfrost/panfrost_gem_shrinker.c
@@ -48,14 +48,14 @@ static bool panfrost_gem_purge(struct drm_gem_object *obj)
if (!mutex_trylock(&bo->mappings.lock))
return false;

- if (!mutex_trylock(&shmem->pages_lock))
+ if (!dma_resv_trylock(shmem->base.resv))
goto unlock_mappings;

panfrost_gem_teardown_mappings_locked(bo);
drm_gem_shmem_purge_locked(&bo->base);
ret = true;

- mutex_unlock(&shmem->pages_lock);
+ dma_resv_unlock(shmem->base.resv);

unlock_mappings:
mutex_unlock(&bo->mappings.lock);
diff --git a/drivers/gpu/drm/panfrost/panfrost_mmu.c b/drivers/gpu/drm/panfrost/panfrost_mmu.c
index b285a8001b1d..9b261a1c7f5c 100644
--- a/drivers/gpu/drm/panfrost/panfrost_mmu.c
+++ b/drivers/gpu/drm/panfrost/panfrost_mmu.c
@@ -424,6 +424,7 @@ static int panfrost_mmu_map_fault_addr(struct panfrost_device *pfdev, int as,
struct panfrost_gem_mapping *bomapping;
struct panfrost_gem_object *bo;
struct address_space *mapping;
+ struct drm_gem_object *obj;
pgoff_t page_offset;
struct sg_table *sgt;
struct page **pages;
@@ -446,13 +447,15 @@ static int panfrost_mmu_map_fault_addr(struct panfrost_device *pfdev, int as,
page_offset = addr >> PAGE_SHIFT;
page_offset -= bomapping->mmnode.start;

- mutex_lock(&bo->base.pages_lock);
+ obj = &bo->base.base;
+
+ dma_resv_lock(obj->resv, NULL);

if (!bo->base.pages) {
bo->sgts = kvmalloc_array(bo->base.base.size / SZ_2M,
sizeof(struct sg_table), GFP_KERNEL | __GFP_ZERO);
if (!bo->sgts) {
- mutex_unlock(&bo->base.pages_lock);
+ dma_resv_unlock(obj->resv);
ret = -ENOMEM;
goto err_bo;
}
@@ -462,7 +465,7 @@ static int panfrost_mmu_map_fault_addr(struct panfrost_device *pfdev, int as,
if (!pages) {
kvfree(bo->sgts);
bo->sgts = NULL;
- mutex_unlock(&bo->base.pages_lock);
+ dma_resv_unlock(obj->resv);
ret = -ENOMEM;
goto err_bo;
}
@@ -472,7 +475,7 @@ static int panfrost_mmu_map_fault_addr(struct panfrost_device *pfdev, int as,
pages = bo->base.pages;
if (pages[page_offset]) {
/* Pages are already mapped, bail out. */
- mutex_unlock(&bo->base.pages_lock);
+ dma_resv_unlock(obj->resv);
goto out;
}
}
@@ -483,13 +486,13 @@ static int panfrost_mmu_map_fault_addr(struct panfrost_device *pfdev, int as,
for (i = page_offset; i < page_offset + NUM_FAULT_PAGES; i++) {
pages[i] = shmem_read_mapping_page(mapping, i);
if (IS_ERR(pages[i])) {
- mutex_unlock(&bo->base.pages_lock);
+ dma_resv_unlock(obj->resv);
ret = PTR_ERR(pages[i]);
goto err_pages;
}
}

- mutex_unlock(&bo->base.pages_lock);
+ dma_resv_unlock(obj->resv);

sgt = &bo->sgts[page_offset / (SZ_2M / PAGE_SIZE)];
ret = sg_alloc_table_from_pages(sgt, pages + page_offset,
diff --git a/include/drm/drm_gem_shmem_helper.h b/include/drm/drm_gem_shmem_helper.h
index d0a57853c188..6f2b8fee620c 100644
--- a/include/drm/drm_gem_shmem_helper.h
+++ b/include/drm/drm_gem_shmem_helper.h
@@ -26,11 +26,6 @@ struct drm_gem_shmem_object {
*/
struct drm_gem_object base;

- /**
- * @pages_lock: Protects the page table and use count
- */
- struct mutex pages_lock;
-
/**
* @pages: Page table
*/
--
2.35.1
\
 
 \ /
  Last update: 2022-04-24 21:06    [W:0.212 / U:0.020 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site