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authorDmitry Osipenko <dmitry.osipenko@collabora.com>2025-03-23 00:26:08 +0300
committerDmitry Osipenko <dmitry.osipenko@collabora.com>2025-03-26 23:00:22 +0300
commite1fc39a923329c34c61dfed0665620d21826e8f4 (patch)
tree92fc6cf6c045a8fc1823747ef1f8bdc07cce0d2f /drivers/gpu/drm/drm_gem_shmem_helper.c
parent0271cc484f3f73d5c6f88d3e43a5d98e07c76381 (diff)
drm/shmem-helper: Use refcount_t for vmap_use_count
Use refcount_t helper for vmap_use_count to make refcounting consistent with pages_use_count and pages_pin_count that use refcount_t. This also makes vmapping to benefit from the refcount_t's overflow checks. Acked-by: Maxime Ripard <mripard@kernel.org> Reviewed-by: Boris Brezillon <boris.brezillon@collabora.com> Suggested-by: Boris Brezillon <boris.brezillon@collabora.com> Acked-by: Thomas Zimmermann <tzimmermann@suse.d> Signed-off-by: Dmitry Osipenko <dmitry.osipenko@collabora.com> Link: https://patchwork.freedesktop.org/patch/msgid/20250322212608.40511-11-dmitry.osipenko@collabora.com
Diffstat (limited to 'drivers/gpu/drm/drm_gem_shmem_helper.c')
-rw-r--r--drivers/gpu/drm/drm_gem_shmem_helper.c28
1 files changed, 12 insertions, 16 deletions
diff --git a/drivers/gpu/drm/drm_gem_shmem_helper.c b/drivers/gpu/drm/drm_gem_shmem_helper.c
index 84a196bbe44f..2d924d547a51 100644
--- a/drivers/gpu/drm/drm_gem_shmem_helper.c
+++ b/drivers/gpu/drm/drm_gem_shmem_helper.c
@@ -165,7 +165,7 @@ void drm_gem_shmem_free(struct drm_gem_shmem_object *shmem)
} else {
dma_resv_lock(shmem->base.resv, NULL);
- drm_WARN_ON(obj->dev, shmem->vmap_use_count);
+ drm_WARN_ON(obj->dev, refcount_read(&shmem->vmap_use_count));
if (shmem->sgt) {
dma_unmap_sgtable(obj->dev->dev, shmem->sgt,
@@ -355,23 +355,25 @@ int drm_gem_shmem_vmap_locked(struct drm_gem_shmem_object *shmem,
dma_resv_assert_held(shmem->base.resv);
- if (shmem->vmap_use_count++ > 0) {
+ if (refcount_inc_not_zero(&shmem->vmap_use_count)) {
iosys_map_set_vaddr(map, shmem->vaddr);
return 0;
}
ret = drm_gem_shmem_pin_locked(shmem);
if (ret)
- goto err_zero_use;
+ return ret;
if (shmem->map_wc)
prot = pgprot_writecombine(prot);
shmem->vaddr = vmap(shmem->pages, obj->size >> PAGE_SHIFT,
VM_MAP, prot);
- if (!shmem->vaddr)
+ if (!shmem->vaddr) {
ret = -ENOMEM;
- else
+ } else {
iosys_map_set_vaddr(map, shmem->vaddr);
+ refcount_set(&shmem->vmap_use_count, 1);
+ }
}
if (ret) {
@@ -384,8 +386,6 @@ int drm_gem_shmem_vmap_locked(struct drm_gem_shmem_object *shmem,
err_put_pages:
if (!drm_gem_is_imported(obj))
drm_gem_shmem_unpin_locked(shmem);
-err_zero_use:
- shmem->vmap_use_count = 0;
return ret;
}
@@ -413,14 +413,10 @@ void drm_gem_shmem_vunmap_locked(struct drm_gem_shmem_object *shmem,
} else {
dma_resv_assert_held(shmem->base.resv);
- if (drm_WARN_ON_ONCE(obj->dev, !shmem->vmap_use_count))
- return;
-
- if (--shmem->vmap_use_count > 0)
- return;
-
- vunmap(shmem->vaddr);
- drm_gem_shmem_unpin_locked(shmem);
+ if (refcount_dec_and_test(&shmem->vmap_use_count)) {
+ vunmap(shmem->vaddr);
+ drm_gem_shmem_unpin_locked(shmem);
+ }
}
shmem->vaddr = NULL;
@@ -672,7 +668,7 @@ void drm_gem_shmem_print_info(const struct drm_gem_shmem_object *shmem,
drm_printf_indent(p, indent, "pages_pin_count=%u\n", refcount_read(&shmem->pages_pin_count));
drm_printf_indent(p, indent, "pages_use_count=%u\n", refcount_read(&shmem->pages_use_count));
- drm_printf_indent(p, indent, "vmap_use_count=%u\n", shmem->vmap_use_count);
+ drm_printf_indent(p, indent, "vmap_use_count=%u\n", refcount_read(&shmem->vmap_use_count));
drm_printf_indent(p, indent, "vaddr=%p\n", shmem->vaddr);
}
EXPORT_SYMBOL_GPL(drm_gem_shmem_print_info);