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path: root/drivers/char/drm/i915_mem.c
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Diffstat (limited to 'drivers/char/drm/i915_mem.c')
-rw-r--r--drivers/char/drm/i915_mem.c346
1 files changed, 346 insertions, 0 deletions
diff --git a/drivers/char/drm/i915_mem.c b/drivers/char/drm/i915_mem.c
new file mode 100644
index 000000000000..d54a3005946b
--- /dev/null
+++ b/drivers/char/drm/i915_mem.c
@@ -0,0 +1,346 @@
+/* i915_mem.c -- Simple agp/fb memory manager for i915 -*- linux-c -*-
+ */
+/**************************************************************************
+ *
+ * Copyright 2003 Tungsten Graphics, Inc., Cedar Park, Texas.
+ * All Rights Reserved.
+ *
+ **************************************************************************/
+
+#include "drmP.h"
+#include "drm.h"
+#include "i915_drm.h"
+#include "i915_drv.h"
+
+/* This memory manager is integrated into the global/local lru
+ * mechanisms used by the clients. Specifically, it operates by
+ * setting the 'in_use' fields of the global LRU to indicate whether
+ * this region is privately allocated to a client.
+ *
+ * This does require the client to actually respect that field.
+ *
+ * Currently no effort is made to allocate 'private' memory in any
+ * clever way - the LRU information isn't used to determine which
+ * block to allocate, and the ring is drained prior to allocations --
+ * in other words allocation is expensive.
+ */
+static void mark_block(drm_device_t * dev, struct mem_block *p, int in_use)
+{
+ drm_i915_private_t *dev_priv = dev->dev_private;
+ drm_i915_sarea_t *sarea_priv = dev_priv->sarea_priv;
+ drm_tex_region_t *list;
+ unsigned shift, nr;
+ unsigned start;
+ unsigned end;
+ unsigned i;
+ int age;
+
+ shift = dev_priv->tex_lru_log_granularity;
+ nr = I915_NR_TEX_REGIONS;
+
+ start = p->start >> shift;
+ end = (p->start + p->size - 1) >> shift;
+
+ age = ++sarea_priv->texAge;
+ list = sarea_priv->texList;
+
+ /* Mark the regions with the new flag and update their age. Move
+ * them to head of list to preserve LRU semantics.
+ */
+ for (i = start; i <= end; i++) {
+ list[i].in_use = in_use;
+ list[i].age = age;
+
+ /* remove_from_list(i)
+ */
+ list[(unsigned)list[i].next].prev = list[i].prev;
+ list[(unsigned)list[i].prev].next = list[i].next;
+
+ /* insert_at_head(list, i)
+ */
+ list[i].prev = nr;
+ list[i].next = list[nr].next;
+ list[(unsigned)list[nr].next].prev = i;
+ list[nr].next = i;
+ }
+}
+
+/* Very simple allocator for agp memory, working on a static range
+ * already mapped into each client's address space.
+ */
+
+static struct mem_block *split_block(struct mem_block *p, int start, int size,
+ DRMFILE filp)
+{
+ /* Maybe cut off the start of an existing block */
+ if (start > p->start) {
+ struct mem_block *newblock = drm_alloc(sizeof(*newblock), DRM_MEM_BUFLISTS);
+ if (!newblock)
+ goto out;
+ newblock->start = start;
+ newblock->size = p->size - (start - p->start);
+ newblock->filp = NULL;
+ newblock->next = p->next;
+ newblock->prev = p;
+ p->next->prev = newblock;
+ p->next = newblock;
+ p->size -= newblock->size;
+ p = newblock;
+ }
+
+ /* Maybe cut off the end of an existing block */
+ if (size < p->size) {
+ struct mem_block *newblock = drm_alloc(sizeof(*newblock), DRM_MEM_BUFLISTS);
+ if (!newblock)
+ goto out;
+ newblock->start = start + size;
+ newblock->size = p->size - size;
+ newblock->filp = NULL;
+ newblock->next = p->next;
+ newblock->prev = p;
+ p->next->prev = newblock;
+ p->next = newblock;
+ p->size = size;
+ }
+
+ out:
+ /* Our block is in the middle */
+ p->filp = filp;
+ return p;
+}
+
+static struct mem_block *alloc_block(struct mem_block *heap, int size,
+ int align2, DRMFILE filp)
+{
+ struct mem_block *p;
+ int mask = (1 << align2) - 1;
+
+ for (p = heap->next; p != heap; p = p->next) {
+ int start = (p->start + mask) & ~mask;
+ if (p->filp == NULL && start + size <= p->start + p->size)
+ return split_block(p, start, size, filp);
+ }
+
+ return NULL;
+}
+
+static struct mem_block *find_block(struct mem_block *heap, int start)
+{
+ struct mem_block *p;
+
+ for (p = heap->next; p != heap; p = p->next)
+ if (p->start == start)
+ return p;
+
+ return NULL;
+}
+
+static void free_block(struct mem_block *p)
+{
+ p->filp = NULL;
+
+ /* Assumes a single contiguous range. Needs a special filp in
+ * 'heap' to stop it being subsumed.
+ */
+ if (p->next->filp == NULL) {
+ struct mem_block *q = p->next;
+ p->size += q->size;
+ p->next = q->next;
+ p->next->prev = p;
+ drm_free(q, sizeof(*q), DRM_MEM_BUFLISTS);
+ }
+
+ if (p->prev->filp == NULL) {
+ struct mem_block *q = p->prev;
+ q->size += p->size;
+ q->next = p->next;
+ q->next->prev = q;
+ drm_free(p, sizeof(*q), DRM_MEM_BUFLISTS);
+ }
+}
+
+/* Initialize. How to check for an uninitialized heap?
+ */
+static int init_heap(struct mem_block **heap, int start, int size)
+{
+ struct mem_block *blocks = drm_alloc(sizeof(*blocks), DRM_MEM_BUFLISTS);
+
+ if (!blocks)
+ return -ENOMEM;
+
+ *heap = drm_alloc(sizeof(**heap), DRM_MEM_BUFLISTS);
+ if (!*heap) {
+ drm_free(blocks, sizeof(*blocks), DRM_MEM_BUFLISTS);
+ return -ENOMEM;
+ }
+
+ blocks->start = start;
+ blocks->size = size;
+ blocks->filp = NULL;
+ blocks->next = blocks->prev = *heap;
+
+ memset(*heap, 0, sizeof(**heap));
+ (*heap)->filp = (DRMFILE) - 1;
+ (*heap)->next = (*heap)->prev = blocks;
+ return 0;
+}
+
+/* Free all blocks associated with the releasing file.
+ */
+void i915_mem_release(drm_device_t * dev, DRMFILE filp, struct mem_block *heap)
+{
+ struct mem_block *p;
+
+ if (!heap || !heap->next)
+ return;
+
+ for (p = heap->next; p != heap; p = p->next) {
+ if (p->filp == filp) {
+ p->filp = NULL;
+ mark_block(dev, p, 0);
+ }
+ }
+
+ /* Assumes a single contiguous range. Needs a special filp in
+ * 'heap' to stop it being subsumed.
+ */
+ for (p = heap->next; p != heap; p = p->next) {
+ while (p->filp == NULL && p->next->filp == NULL) {
+ struct mem_block *q = p->next;
+ p->size += q->size;
+ p->next = q->next;
+ p->next->prev = p;
+ drm_free(q, sizeof(*q), DRM_MEM_BUFLISTS);
+ }
+ }
+}
+
+/* Shutdown.
+ */
+void i915_mem_takedown(struct mem_block **heap)
+{
+ struct mem_block *p;
+
+ if (!*heap)
+ return;
+
+ for (p = (*heap)->next; p != *heap;) {
+ struct mem_block *q = p;
+ p = p->next;
+ drm_free(q, sizeof(*q), DRM_MEM_BUFLISTS);
+ }
+
+ drm_free(*heap, sizeof(**heap), DRM_MEM_BUFLISTS);
+ *heap = NULL;
+}
+
+static struct mem_block **get_heap(drm_i915_private_t * dev_priv, int region)
+{
+ switch (region) {
+ case I915_MEM_REGION_AGP:
+ return &dev_priv->agp_heap;
+ default:
+ return NULL;
+ }
+}
+
+/* IOCTL HANDLERS */
+
+int i915_mem_alloc(DRM_IOCTL_ARGS)
+{
+ DRM_DEVICE;
+ drm_i915_private_t *dev_priv = dev->dev_private;
+ drm_i915_mem_alloc_t alloc;
+ struct mem_block *block, **heap;
+
+ if (!dev_priv) {
+ DRM_ERROR("%s called with no initialization\n", __FUNCTION__);
+ return DRM_ERR(EINVAL);
+ }
+
+ DRM_COPY_FROM_USER_IOCTL(alloc, (drm_i915_mem_alloc_t __user *) data,
+ sizeof(alloc));
+
+ heap = get_heap(dev_priv, alloc.region);
+ if (!heap || !*heap)
+ return DRM_ERR(EFAULT);
+
+ /* Make things easier on ourselves: all allocations at least
+ * 4k aligned.
+ */
+ if (alloc.alignment < 12)
+ alloc.alignment = 12;
+
+ block = alloc_block(*heap, alloc.size, alloc.alignment, filp);
+
+ if (!block)
+ return DRM_ERR(ENOMEM);
+
+ mark_block(dev, block, 1);
+
+ if (DRM_COPY_TO_USER(alloc.region_offset, &block->start, sizeof(int))) {
+ DRM_ERROR("copy_to_user\n");
+ return DRM_ERR(EFAULT);
+ }
+
+ return 0;
+}
+
+int i915_mem_free(DRM_IOCTL_ARGS)
+{
+ DRM_DEVICE;
+ drm_i915_private_t *dev_priv = dev->dev_private;
+ drm_i915_mem_free_t memfree;
+ struct mem_block *block, **heap;
+
+ if (!dev_priv) {
+ DRM_ERROR("%s called with no initialization\n", __FUNCTION__);
+ return DRM_ERR(EINVAL);
+ }
+
+ DRM_COPY_FROM_USER_IOCTL(memfree, (drm_i915_mem_free_t __user *) data,
+ sizeof(memfree));
+
+ heap = get_heap(dev_priv, memfree.region);
+ if (!heap || !*heap)
+ return DRM_ERR(EFAULT);
+
+ block = find_block(*heap, memfree.region_offset);
+ if (!block)
+ return DRM_ERR(EFAULT);
+
+ if (block->filp != filp)
+ return DRM_ERR(EPERM);
+
+ mark_block(dev, block, 0);
+ free_block(block);
+ return 0;
+}
+
+int i915_mem_init_heap(DRM_IOCTL_ARGS)
+{
+ DRM_DEVICE;
+ drm_i915_private_t *dev_priv = dev->dev_private;
+ drm_i915_mem_init_heap_t initheap;
+ struct mem_block **heap;
+
+ if (!dev_priv) {
+ DRM_ERROR("%s called with no initialization\n", __FUNCTION__);
+ return DRM_ERR(EINVAL);
+ }
+
+ DRM_COPY_FROM_USER_IOCTL(initheap,
+ (drm_i915_mem_init_heap_t __user *) data,
+ sizeof(initheap));
+
+ heap = get_heap(dev_priv, initheap.region);
+ if (!heap)
+ return DRM_ERR(EFAULT);
+
+ if (*heap) {
+ DRM_ERROR("heap already initialized?");
+ return DRM_ERR(EFAULT);
+ }
+
+ return init_heap(heap, initheap.start, initheap.size);
+}