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authorJesse Barnes <jbarnes@virtuousgeek.org>2008-12-09 10:23:43 -0800
committerJesse Barnes <jbarnes@virtuousgeek.org>2008-12-09 10:23:43 -0800
commit6656db10551bbb8770dd945b6d81d5138521f208 (patch)
tree68e457660c174ee2e16353691126ddd754c79398 /linux-core/drm_uncached.c
parentc99566fb810c9d8cae5e9cd39d1772b55e2f514c (diff)
parent12e68f8059485fb4f02a15f74ab2fa3bdff38c81 (diff)
Merge branch 'modesetting-gem'
Diffstat (limited to 'linux-core/drm_uncached.c')
-rw-r--r--linux-core/drm_uncached.c138
1 files changed, 138 insertions, 0 deletions
diff --git a/linux-core/drm_uncached.c b/linux-core/drm_uncached.c
new file mode 100644
index 00000000..9c7183b0
--- /dev/null
+++ b/linux-core/drm_uncached.c
@@ -0,0 +1,138 @@
+/*
+ * Copyright (c) Red Hat Inc.
+
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sub license,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice (including the
+ * next paragraph) shall be included in all copies or substantial portions
+ * of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+ * DEALINGS IN THE SOFTWARE.
+ *
+ * Authors: Dave Airlie <airlied@redhat.com>
+ */
+
+/* simple list based uncached page allocator
+ * - Add chunks of 1MB to the allocator at a time.
+ * - Use page->lru to keep a free list
+ * - doesn't track currently in use pages
+ *
+ * TODO: Add shrinker support
+ */
+
+#include "drmP.h"
+#include <asm/agp.h>
+
+static struct list_head uncached_free_list;
+
+static struct mutex uncached_mutex;
+static int uncached_inited;
+static int total_uncached_pages;
+
+/* add 1MB at a time */
+#define NUM_PAGES_TO_ADD 256
+
+static void drm_uncached_page_put(struct page *page)
+{
+ unmap_page_from_agp(page);
+ put_page(page);
+ __free_page(page);
+}
+
+int drm_uncached_add_pages_locked(int num_pages)
+{
+ struct page *page;
+ int i;
+
+ DRM_DEBUG("adding uncached memory %ld\n", num_pages * PAGE_SIZE);
+ for (i = 0; i < num_pages; i++) {
+
+ page = alloc_page(GFP_KERNEL | __GFP_ZERO | GFP_DMA32);
+ if (!page) {
+ DRM_ERROR("unable to get page %d\n", i);
+ return i;
+ }
+
+ get_page(page);
+#ifdef CONFIG_X86
+ set_memory_wc((unsigned long)page_address(page), 1);
+#else
+ map_page_into_agp(page);
+#endif
+
+ list_add(&page->lru, &uncached_free_list);
+ total_uncached_pages++;
+ }
+ return i;
+}
+
+struct page *drm_get_uncached_page(void)
+{
+ struct page *page = NULL;
+ int ret;
+
+ mutex_lock(&uncached_mutex);
+ if (list_empty(&uncached_free_list)) {
+ ret = drm_uncached_add_pages_locked(NUM_PAGES_TO_ADD);
+ if (ret == 0)
+ return NULL;
+ }
+
+ page = list_first_entry(&uncached_free_list, struct page, lru);
+ list_del(&page->lru);
+
+ mutex_unlock(&uncached_mutex);
+ return page;
+}
+
+void drm_put_uncached_page(struct page *page)
+{
+ mutex_lock(&uncached_mutex);
+ list_add(&page->lru, &uncached_free_list);
+ mutex_unlock(&uncached_mutex);
+}
+
+void drm_uncached_release_all_pages(void)
+{
+ struct page *page, *tmp;
+
+ list_for_each_entry_safe(page, tmp, &uncached_free_list, lru) {
+ list_del(&page->lru);
+ drm_uncached_page_put(page);
+ }
+}
+
+int drm_uncached_init(void)
+{
+
+ if (uncached_inited)
+ return 0;
+
+ INIT_LIST_HEAD(&uncached_free_list);
+
+ mutex_init(&uncached_mutex);
+ uncached_inited = 1;
+ return 0;
+
+}
+
+void drm_uncached_fini(void)
+{
+ if (!uncached_inited)
+ return;
+
+ uncached_inited = 0;
+ drm_uncached_release_all_pages();
+}
+