Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
drm/vmwgfx: Use kref in vmw_bo_dirty
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
authored by
Ian Forbes
and committed by
Zack Rusin
c1962742
32b415a9
+5
-7
+5
-7
drivers/gpu/drm/vmwgfx/vmwgfx_page_dirty.c
+5
-7
drivers/gpu/drm/vmwgfx/vmwgfx_page_dirty.c
···
32
32
33
33
/**
34
34
* struct vmw_bo_dirty - Dirty information for buffer objects
35
+
* @ref_count: Reference count for this structure. Must be first member!
35
36
* @start: First currently dirty bit
36
37
* @end: Last currently dirty bit + 1
37
38
* @method: The currently used dirty method
38
39
* @change_count: Number of consecutive method change triggers
39
-
* @ref_count: Reference count for this structure
40
40
* @bitmap_size: The size of the bitmap in bits. Typically equal to the
41
41
* nuber of pages in the bo.
42
42
* @bitmap: A bitmap where each bit represents a page. A set bit means a
43
43
* dirty page.
44
44
*/
45
45
struct vmw_bo_dirty {
46
+
struct kref ref_count;
46
47
unsigned long start;
47
48
unsigned long end;
48
49
enum vmw_bo_dirty_method method;
49
50
unsigned int change_count;
50
-
unsigned int ref_count;
51
51
unsigned long bitmap_size;
52
52
unsigned long bitmap[];
53
53
};
···
221
221
int ret;
222
222
223
223
if (dirty) {
224
-
dirty->ref_count++;
224
+
kref_get(&dirty->ref_count);
225
225
return 0;
226
226
}
227
227
···
235
235
dirty->bitmap_size = num_pages;
236
236
dirty->start = dirty->bitmap_size;
237
237
dirty->end = 0;
238
-
dirty->ref_count = 1;
238
+
kref_init(&dirty->ref_count);
239
239
if (num_pages < PAGE_SIZE / sizeof(pte_t)) {
240
240
dirty->method = VMW_BO_DIRTY_PAGETABLE;
241
241
} else {
···
274
274
{
275
275
struct vmw_bo_dirty *dirty = vbo->dirty;
276
276
277
-
if (dirty && --dirty->ref_count == 0) {
278
-
kvfree(dirty);
277
+
if (dirty && kref_put(&dirty->ref_count, (void *)kvfree))
279
278
vbo->dirty = NULL;
280
-
}
281
279
}
282
280
283
281
/**