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);
+}