drm/vmwgfx/vmwgfx_page_dirty.c

31  * Different methods for tracking dirty:
32  * VMW_BO_DIRTY_PAGETABLE - Scan the pagetable for hardware dirty bits
43  * similarly a certain percentage of dirty pages trigger a transition to
54  * @start: First currently dirty bit
55  * @end: Last currently dirty bit + 1
56  * @method: The currently used dirty method
62  * dirty page.
75  * vmw_bo_dirty_scan_pagetable - Perform a pagetable scan for dirty bits
78  * Scans the pagetable for dirty bits. Clear those bits and modify the
79  * dirty structure with the results. This function may change the
80  * dirty-tracking method.
84 	struct vmw_bo_dirty *dirty = vbo->dirty;
91 		 offset, dirty->bitmap_size,
92 		 offset, &dirty->bitmap[0],
93 		 &dirty->start, &dirty->end);
95 		dirty->change_count++;
97 		dirty->change_count = 0;
99 	if (dirty->change_count > VMW_DIRTY_NUM_CHANGE_TRIGGERS) {
100 		dirty->change_count = 0;
101 		dirty->method = VMW_BO_DIRTY_MKWRITE;
103 					offset, dirty->bitmap_size);
105 						  offset, dirty->bitmap_size,
106 						  offset, &dirty->bitmap[0],
107 						  &dirty->start, &dirty->end);
112  * vmw_bo_dirty_scan_mkwrite - Reset the mkwrite dirty-tracking method
118  * This function may change the dirty-tracking method.
122 	struct vmw_bo_dirty *dirty = vbo->dirty;
127 	if (dirty->end <= dirty->start)
131 					     dirty->start + offset,
132 					     dirty->end - dirty->start);
134 	if (100UL * num_marked / dirty->bitmap_size >
136 		dirty->change_count++;
138 		dirty->change_count = 0;
140 	if (dirty->change_count > VMW_DIRTY_NUM_CHANGE_TRIGGERS) {
142 		pgoff_t end = dirty->bitmap_size;
144 		dirty->method = VMW_BO_DIRTY_PAGETABLE;
146 						  &dirty->bitmap[0],
148 		bitmap_clear(&dirty->bitmap[0], 0, dirty->bitmap_size);
149 		if (dirty->start < dirty->end)
150 			bitmap_set(&dirty->bitmap[0], dirty->start,
151 				   dirty->end - dirty->start);
152 		dirty->change_count = 0;
157  * vmw_bo_dirty_scan - Scan for dirty pages and add them to the dirty
161  * This function may change the dirty tracking method.
165 	struct vmw_bo_dirty *dirty = vbo->dirty;
167 	if (dirty->method == VMW_BO_DIRTY_PAGETABLE)
174  * vmw_bo_dirty_pre_unmap - write-protect and pick up dirty pages before
180  * If we're using the _PAGETABLE scan method, we may leak dirty pages
182  * up all dirty pages.
187 	struct vmw_bo_dirty *dirty = vbo->dirty;
191 	if (dirty->method != VMW_BO_DIRTY_PAGETABLE || start >= end)
197 					  &dirty->bitmap[0], &dirty->start,
198 					  &dirty->end);
221  * vmw_bo_dirty_add - Add a dirty-tracking user to a buffer object
224  * This function registers a dirty-tracking user to a buffer object.
232 	struct vmw_bo_dirty *dirty = vbo->dirty;
237 	if (dirty) {
238 		dirty->ref_count++;
242 	size = sizeof(*dirty) + BITS_TO_LONGS(num_pages) * sizeof(long);
243 	dirty = kvzalloc(size, GFP_KERNEL);
244 	if (!dirty) {
249 	dirty->bitmap_size = num_pages;
250 	dirty->start = dirty->bitmap_size;
251 	dirty->end = 0;
252 	dirty->ref_count = 1;
254 		dirty->method = VMW_BO_DIRTY_PAGETABLE;
259 		dirty->method = VMW_BO_DIRTY_MKWRITE;
261 		/* Write-protect and then pick up already dirty bits */
265 						  &dirty->bitmap[0],
266 						  &dirty->start, &dirty->end);
269 	vbo->dirty = dirty;
278  * vmw_bo_dirty_release - Release a dirty-tracking user from a buffer object
281  * This function releases a dirty-tracking user from a buffer object.
282  * If the reference count reaches zero, then the dirty-tracking object is
289 	struct vmw_bo_dirty *dirty = vbo->dirty;
291 	if (dirty && --dirty->ref_count == 0) {
292 		kvfree(dirty);
293 		vbo->dirty = NULL;
298  * vmw_bo_dirty_transfer_to_res - Pick up a resource's dirty region from
302  * This function will pick up all dirty ranges affecting the resource from
305  * dirty tracking.
310 	struct vmw_bo_dirty *dirty = vbo->dirty;
319 	if (res_start >= dirty->end || res_end <= dirty->start)
322 	cur = max(res_start, dirty->start);
323 	res_end = max(res_end, dirty->end);
327 		start = find_next_bit(&dirty->bitmap[0], res_end, cur);
331 		end = find_next_zero_bit(&dirty->bitmap[0], res_end, start + 1);
334 		bitmap_clear(&dirty->bitmap[0], start, num);
338 	if (res_start <= dirty->start && res_end > dirty->start)
339 		dirty->start = res_end;
340 	if (res_start < dirty->end && res_end >= dirty->end)
341 		dirty->end = res_start;
345  * vmw_bo_dirty_clear_res - Clear a resource's dirty region from
349  * This function will clear all dirty ranges affecting the resource from
350  * it's backup mob's dirty tracking.
357 	struct vmw_bo_dirty *dirty = vbo->dirty;
362 	if (res_start >= dirty->end || res_end <= dirty->start)
365 	res_start = max(res_start, dirty->start);
366 	res_end = min(res_end, dirty->end);
367 	bitmap_clear(&dirty->bitmap[0], res_start, res_end - res_start);
369 	if (res_start <= dirty->start && res_end > dirty->start)
370 		dirty->start = res_end;
371 	if (res_start < dirty->end && res_end >= dirty->end)
372 		dirty->end = res_start;
402 	if (vbo->dirty && vbo->dirty->method == VMW_BO_DIRTY_MKWRITE &&
403 	    !test_bit(page_offset, &vbo->dirty->bitmap[0])) {
404 		struct vmw_bo_dirty *dirty = vbo->dirty;
406 		__set_bit(page_offset, &dirty->bitmap[0]);
407 		dirty->start = min(dirty->start, page_offset);
408 		dirty->end = max(dirty->end, page_offset + 1);
433 	if (vbo->dirty) {
451 	 * If we don't track dirty using the MKWRITE method, make sure
455 	if (vbo->dirty && vbo->dirty->method == VMW_BO_DIRTY_MKWRITE)