6.6-stable review patch. If anyone has any objections, please let me know.
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From: Ian Forbes ian.forbes@broadcom.com
[ Upstream commit c1962742ffff7e245f935903a4658eb6f94f6058 ]
Rather than using an ad hoc reference count use kref which is atomic and has underflow warnings.
Signed-off-by: Ian Forbes ian.forbes@broadcom.com Signed-off-by: Zack Rusin zack.rusin@broadcom.com Link: https://patch.msgid.link/20251030193640.153697-1-ian.forbes@broadcom.com Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/gpu/drm/vmwgfx/vmwgfx_page_dirty.c | 12 +++++------- 1 file changed, 5 insertions(+), 7 deletions(-)
diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_page_dirty.c b/drivers/gpu/drm/vmwgfx/vmwgfx_page_dirty.c index 74ff2812d66a1..de2498749e276 100644 --- a/drivers/gpu/drm/vmwgfx/vmwgfx_page_dirty.c +++ b/drivers/gpu/drm/vmwgfx/vmwgfx_page_dirty.c @@ -51,22 +51,22 @@ enum vmw_bo_dirty_method {
/** * struct vmw_bo_dirty - Dirty information for buffer objects + * @ref_count: Reference count for this structure. Must be first member! * @start: First currently dirty bit * @end: Last currently dirty bit + 1 * @method: The currently used dirty method * @change_count: Number of consecutive method change triggers - * @ref_count: Reference count for this structure * @bitmap_size: The size of the bitmap in bits. Typically equal to the * nuber of pages in the bo. * @bitmap: A bitmap where each bit represents a page. A set bit means a * dirty page. */ struct vmw_bo_dirty { + struct kref ref_count; unsigned long start; unsigned long end; enum vmw_bo_dirty_method method; unsigned int change_count; - unsigned int ref_count; unsigned long bitmap_size; unsigned long bitmap[]; }; @@ -235,7 +235,7 @@ int vmw_bo_dirty_add(struct vmw_bo *vbo) int ret;
if (dirty) { - dirty->ref_count++; + kref_get(&dirty->ref_count); return 0; }
@@ -249,7 +249,7 @@ int vmw_bo_dirty_add(struct vmw_bo *vbo) dirty->bitmap_size = num_pages; dirty->start = dirty->bitmap_size; dirty->end = 0; - dirty->ref_count = 1; + kref_init(&dirty->ref_count); if (num_pages < PAGE_SIZE / sizeof(pte_t)) { dirty->method = VMW_BO_DIRTY_PAGETABLE; } else { @@ -288,10 +288,8 @@ void vmw_bo_dirty_release(struct vmw_bo *vbo) { struct vmw_bo_dirty *dirty = vbo->dirty;
- if (dirty && --dirty->ref_count == 0) { - kvfree(dirty); + if (dirty && kref_put(&dirty->ref_count, (void *)kvfree)) vbo->dirty = NULL; - } }
/**