Commit c1962742 authored by Ian Forbes's avatar Ian Forbes Committed by Zack Rusin
Browse files

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: default avatarIan Forbes <ian.forbes@broadcom.com>
Signed-off-by: default avatarZack Rusin <zack.rusin@broadcom.com>
Link: https://patch.msgid.link/20251030193640.153697-1-ian.forbes@broadcom.com
parent 32b415a9

drivers/gpu/drm/vmwgfx/vmwgfx_page_dirty.c

+5 −7
Original line number Diff line number Diff line
@@ -32,22 +32,22 @@ 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[];

};
@@ -221,7 +221,7 @@ int vmw_bo_dirty_add(struct vmw_bo *vbo) 
	int ret;



	if (dirty) {

		dirty->ref_count++;

		kref_get(&dirty->ref_count);

		return 0;

	}
@@ -235,7 +235,7 @@ 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 {
@@ -274,11 +274,9 @@ 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;

}

}



/**

 * vmw_bo_dirty_transfer_to_res - Pick up a resource's dirty region from