1 files changed, 693 insertions, 0 deletions

diff --git a/arch/powerpc/lib/rheap.c b/arch/powerpc/lib/rheap.c
new file mode 100644
index 000000000000..42c5de2c898f
--- /dev/null
+++ b/arch/powerpc/lib/rheap.c
@@ -0,0 +1,693 @@
+/*
+ * arch/ppc/syslib/rheap.c
+ *
+ * A Remote Heap.  Remote means that we don't touch the memory that the
+ * heap points to. Normal heap implementations use the memory they manage
+ * to place their list. We cannot do that because the memory we manage may
+ * have special properties, for example it is uncachable or of different
+ * endianess.
+ *
+ * Author: Pantelis Antoniou <panto@intracom.gr>
+ *
+ * 2004 (c) INTRACOM S.A. Greece. This file is licensed under
+ * the terms of the GNU General Public License version 2. This program
+ * is licensed "as is" without any warranty of any kind, whether express
+ * or implied.
+ */
+#include <linux/types.h>
+#include <linux/errno.h>
+#include <linux/mm.h>
+#include <linux/slab.h>
+
+#include <asm/rheap.h>
+
+/*
+ * Fixup a list_head, needed when copying lists.  If the pointers fall
+ * between s and e, apply the delta.  This assumes that
+ * sizeof(struct list_head *) == sizeof(unsigned long *).
+ */
+static inline void fixup(unsigned long s, unsigned long e, int d,
+                         struct list_head *l)
+{
+        unsigned long *pp;
+
+        pp = (unsigned long *)&l->next;
+        if (*pp >= s && *pp < e)
+                *pp += d;
+
+        pp = (unsigned long *)&l->prev;
+        if (*pp >= s && *pp < e)
+                *pp += d;
+}
+
+/* Grow the allocated blocks */
+static int grow(rh_info_t * info, int max_blocks)
+{
+        rh_block_t *block, *blk;
+        int i, new_blocks;
+        int delta;
+        unsigned long blks, blke;
+
+        if (max_blocks <= info->max_blocks)
+                return -EINVAL;
+
+        new_blocks = max_blocks - info->max_blocks;
+
+        block = kmalloc(sizeof(rh_block_t) * max_blocks, GFP_KERNEL);
+        if (block == NULL)
+                return -ENOMEM;
+
+        if (info->max_blocks > 0) {
+
+                /* copy old block area */
+                memcpy(block, info->block,
+                       sizeof(rh_block_t) * info->max_blocks);
+
+                delta = (char *)block - (char *)info->block;
+
+                /* and fixup list pointers */
+                blks = (unsigned long)info->block;
+                blke = (unsigned long)(info->block + info->max_blocks);
+
+                for (i = 0, blk = block; i < info->max_blocks; i++, blk++)
+                        fixup(blks, blke, delta, &blk->list);
+
+                fixup(blks, blke, delta, &info->empty_list);
+                fixup(blks, blke, delta, &info->free_list);
+                fixup(blks, blke, delta, &info->taken_list);
+
+                /* free the old allocated memory */
+                if ((info->flags & RHIF_STATIC_BLOCK) == 0)
+                        kfree(info->block);
+        }
+
+        info->block = block;
+        info->empty_slots += new_blocks;
+        info->max_blocks = max_blocks;
+        info->flags &= ~RHIF_STATIC_BLOCK;
+
+        /* add all new blocks to the free list */
+        for (i = 0, blk = block + info->max_blocks; i < new_blocks; i++, blk++)
+                list_add(&blk->list, &info->empty_list);
+
+        return 0;
+}
+
+/*
+ * Assure at least the required amount of empty slots.  If this function
+ * causes a grow in the block area then all pointers kept to the block
+ * area are invalid!
+ */
+static int assure_empty(rh_info_t * info, int slots)
+{
+        int max_blocks;
+
+        /* This function is not meant to be used to grow uncontrollably */
+        if (slots >= 4)
+                return -EINVAL;
+
+        /* Enough space */
+        if (info->empty_slots >= slots)
+                return 0;
+
+        /* Next 16 sized block */
+        max_blocks = ((info->max_blocks + slots) + 15) & ~15;
+
+        return grow(info, max_blocks);
+}
+
+static rh_block_t *get_slot(rh_info_t * info)
+{
+        rh_block_t *blk;
+
+        /* If no more free slots, and failure to extend. */
+        /* XXX: You should have called assure_empty before */
+        if (info->empty_slots == 0) {
+                printk(KERN_ERR "rh: out of slots; crash is imminent.\n");
+                return NULL;
+        }
+
+        /* Get empty slot to use */
+        blk = list_entry(info->empty_list.next, rh_block_t, list);
+        list_del_init(&blk->list);
+        info->empty_slots--;
+
+        /* Initialize */
+        blk->start = NULL;
+        blk->size = 0;
+        blk->owner = NULL;
+
+        return blk;
+}
+
+static inline void release_slot(rh_info_t * info, rh_block_t * blk)
+{
+        list_add(&blk->list, &info->empty_list);
+        info->empty_slots++;
+}
+
+static void attach_free_block(rh_info_t * info, rh_block_t * blkn)
+{
+        rh_block_t *blk;
+        rh_block_t *before;
+        rh_block_t *after;
+        rh_block_t *next;
+        int size;
+        unsigned long s, e, bs, be;
+        struct list_head *l;
+
+        /* We assume that they are aligned properly */
+        size = blkn->size;
+        s = (unsigned long)blkn->start;
+        e = s + size;
+
+        /* Find the blocks immediately before and after the given one
+         * (if any) */
+        before = NULL;
+        after = NULL;
+        next = NULL;
+
+        list_for_each(l, &info->free_list) {
+                blk = list_entry(l, rh_block_t, list);
+
+                bs = (unsigned long)blk->start;
+                be = bs + blk->size;
+
+                if (next == NULL && s >= bs)
+                        next = blk;
+
+                if (be == s)
+                        before = blk;
+
+                if (e == bs)
+                        after = blk;
+
+                /* If both are not null, break now */
+                if (before != NULL && after != NULL)
+                        break;
+        }
+
+        /* Now check if they are really adjacent */
+        if (before != NULL && s != (unsigned long)before->start + before->size)
+                before = NULL;
+
+        if (after != NULL && e != (unsigned long)after->start)
+                after = NULL;
+
+        /* No coalescing; list insert and return */
+        if (before == NULL && after == NULL) {
+
+                if (next != NULL)
+                        list_add(&blkn->list, &next->list);
+                else
+                        list_add(&blkn->list, &info->free_list);
+
+                return;
+        }
+
+        /* We don't need it anymore */
+        release_slot(info, blkn);
+
+        /* Grow the before block */
+        if (before != NULL && after == NULL) {
+                before->size += size;
+                return;
+        }
+
+        /* Grow the after block backwards */
+        if (before == NULL && after != NULL) {
+                after->start = (int8_t *)after->start - size;
+                after->size += size;
+                return;
+        }
+
+        /* Grow the before block, and release the after block */
+        before->size += size + after->size;
+        list_del(&after->list);
+        release_slot(info, after);
+}
+
+static void attach_taken_block(rh_info_t * info, rh_block_t * blkn)
+{
+        rh_block_t *blk;
+        struct list_head *l;
+
+        /* Find the block immediately before the given one (if any) */
+        list_for_each(l, &info->taken_list) {
+                blk = list_entry(l, rh_block_t, list);
+                if (blk->start > blkn->start) {
+                        list_add_tail(&blkn->list, &blk->list);
+                        return;
+                }
+        }
+
+        list_add_tail(&blkn->list, &info->taken_list);
+}
+
+/*
+ * Create a remote heap dynamically.  Note that no memory for the blocks
+ * are allocated.  It will upon the first allocation
+ */
+rh_info_t *rh_create(unsigned int alignment)
+{
+        rh_info_t *info;
+
+        /* Alignment must be a power of two */
+        if ((alignment & (alignment - 1)) != 0)
+                return ERR_PTR(-EINVAL);
+
+        info = kmalloc(sizeof(*info), GFP_KERNEL);
+        if (info == NULL)
+                return ERR_PTR(-ENOMEM);
+
+        info->alignment = alignment;
+
+        /* Initially everything as empty */
+        info->block = NULL;
+        info->max_blocks = 0;
+        info->empty_slots = 0;
+        info->flags = 0;
+
+        INIT_LIST_HEAD(&info->empty_list);
+        INIT_LIST_HEAD(&info->free_list);
+        INIT_LIST_HEAD(&info->taken_list);
+
+        return info;
+}
+
+/*
+ * Destroy a dynamically created remote heap.  Deallocate only if the areas
+ * are not static
+ */
+void rh_destroy(rh_info_t * info)
+{
+        if ((info->flags & RHIF_STATIC_BLOCK) == 0 && info->block != NULL)
+                kfree(info->block);
+
+        if ((info->flags & RHIF_STATIC_INFO) == 0)
+                kfree(info);
+}
+
+/*
+ * Initialize in place a remote heap info block.  This is needed to support
+ * operation very early in the startup of the kernel, when it is not yet safe
+ * to call kmalloc.
+ */
+void rh_init(rh_info_t * info, unsigned int alignment, int max_blocks,
+             rh_block_t * block)
+{
+        int i;
+        rh_block_t *blk;
+
+        /* Alignment must be a power of two */
+        if ((alignment & (alignment - 1)) != 0)
+                return;
+
+        info->alignment = alignment;
+
+        /* Initially everything as empty */
+        info->block = block;
+        info->max_blocks = max_blocks;
+        info->empty_slots = max_blocks;
+        info->flags = RHIF_STATIC_INFO | RHIF_STATIC_BLOCK;
+
+        INIT_LIST_HEAD(&info->empty_list);
+        INIT_LIST_HEAD(&info->free_list);
+        INIT_LIST_HEAD(&info->taken_list);
+
+        /* Add all new blocks to the free list */
+        for (i = 0, blk = block; i < max_blocks; i++, blk++)
+                list_add(&blk->list, &info->empty_list);
+}
+
+/* Attach a free memory region, coalesces regions if adjuscent */
+int rh_attach_region(rh_info_t * info, void *start, int size)
+{
+        rh_block_t *blk;
+        unsigned long s, e, m;
+        int r;
+
+        /* The region must be aligned */
+        s = (unsigned long)start;
+        e = s + size;
+        m = info->alignment - 1;
+
+        /* Round start up */
+        s = (s + m) & ~m;
+
+        /* Round end down */
+        e = e & ~m;
+
+        /* Take final values */
+        start = (void *)s;
+        size = (int)(e - s);
+
+        /* Grow the blocks, if needed */
+        r = assure_empty(info, 1);
+        if (r < 0)
+                return r;
+
+        blk = get_slot(info);
+        blk->start = start;
+        blk->size = size;
+        blk->owner = NULL;
+
+        attach_free_block(info, blk);
+
+        return 0;
+}
+
+/* Detatch given address range, splits free block if needed. */
+void *rh_detach_region(rh_info_t * info, void *start, int size)
+{
+        struct list_head *l;
+        rh_block_t *blk, *newblk;
+        unsigned long s, e, m, bs, be;
+
+        /* Validate size */
+        if (size <= 0)
+                return ERR_PTR(-EINVAL);
+
+        /* The region must be aligned */
+        s = (unsigned long)start;
+        e = s + size;
+        m = info->alignment - 1;
+
+        /* Round start up */
+        s = (s + m) & ~m;
+
+        /* Round end down */
+        e = e & ~m;
+
+        if (assure_empty(info, 1) < 0)
+                return ERR_PTR(-ENOMEM);
+
+        blk = NULL;
+        list_for_each(l, &info->free_list) {
+                blk = list_entry(l, rh_block_t, list);
+                /* The range must lie entirely inside one free block */
+                bs = (unsigned long)blk->start;
+                be = (unsigned long)blk->start + blk->size;
+                if (s >= bs && e <= be)
+                        break;
+                blk = NULL;
+        }
+
+        if (blk == NULL)
+                return ERR_PTR(-ENOMEM);
+
+        /* Perfect fit */
+        if (bs == s && be == e) {
+                /* Delete from free list, release slot */
+                list_del(&blk->list);
+                release_slot(info, blk);
+                return (void *)s;
+        }
+
+        /* blk still in free list, with updated start and/or size */
+        if (bs == s || be == e) {
+                if (bs == s)
+                        blk->start = (int8_t *)blk->start + size;
+                blk->size -= size;
+
+        } else {
+                /* The front free fragment */
+                blk->size = s - bs;
+
+                /* the back free fragment */
+                newblk = get_slot(info);
+                newblk->start = (void *)e;
+                newblk->size = be - e;
+
+                list_add(&newblk->list, &blk->list);
+        }
+
+        return (void *)s;
+}
+
+void *rh_alloc(rh_info_t * info, int size, const char *owner)
+{
+        struct list_head *l;
+        rh_block_t *blk;
+        rh_block_t *newblk;
+        void *start;
+
+        /* Validate size */
+        if (size <= 0)
+                return ERR_PTR(-EINVAL);
+
+        /* Align to configured alignment */
+        size = (size + (info->alignment - 1)) & ~(info->alignment - 1);
+
+        if (assure_empty(info, 1) < 0)
+                return ERR_PTR(-ENOMEM);
+
+        blk = NULL;
+        list_for_each(l, &info->free_list) {
+                blk = list_entry(l, rh_block_t, list);
+                if (size <= blk->size)
+                        break;
+                blk = NULL;
+        }
+
+        if (blk == NULL)
+                return ERR_PTR(-ENOMEM);
+
+        /* Just fits */
+        if (blk->size == size) {
+                /* Move from free list to taken list */
+                list_del(&blk->list);
+                blk->owner = owner;
+                start = blk->start;
+
+                attach_taken_block(info, blk);
+
+                return start;
+        }
+
+        newblk = get_slot(info);
+        newblk->start = blk->start;
+        newblk->size = size;
+        newblk->owner = owner;
+
+        /* blk still in free list, with updated start, size */
+        blk->start = (int8_t *)blk->start + size;
+        blk->size -= size;
+
+        start = newblk->start;
+
+        attach_taken_block(info, newblk);
+
+        return start;
+}
+
+/* allocate at precisely the given address */
+void *rh_alloc_fixed(rh_info_t * info, void *start, int size, const char *owner)
+{
+        struct list_head *l;
+        rh_block_t *blk, *newblk1, *newblk2;
+        unsigned long s, e, m, bs, be;
+
+        /* Validate size */
+        if (size <= 0)
+                return ERR_PTR(-EINVAL);
+
+        /* The region must be aligned */
+        s = (unsigned long)start;
+        e = s + size;
+        m = info->alignment - 1;
+
+        /* Round start up */
+        s = (s + m) & ~m;
+
+        /* Round end down */
+        e = e & ~m;
+
+        if (assure_empty(info, 2) < 0)
+                return ERR_PTR(-ENOMEM);
+
+        blk = NULL;
+        list_for_each(l, &info->free_list) {
+                blk = list_entry(l, rh_block_t, list);
+                /* The range must lie entirely inside one free block */
+                bs = (unsigned long)blk->start;
+                be = (unsigned long)blk->start + blk->size;
+                if (s >= bs && e <= be)
+                        break;
+        }
+
+        if (blk == NULL)
+                return ERR_PTR(-ENOMEM);
+
+        /* Perfect fit */
+        if (bs == s && be == e) {
+                /* Move from free list to taken list */
+                list_del(&blk->list);
+                blk->owner = owner;
+
+                start = blk->start;
+                attach_taken_block(info, blk);
+
+                return start;
+
+        }
+
+        /* blk still in free list, with updated start and/or size */
+        if (bs == s || be == e) {
+                if (bs == s)
+                        blk->start = (int8_t *)blk->start + size;
+                blk->size -= size;
+
+        } else {
+                /* The front free fragment */
+                blk->size = s - bs;
+
+                /* The back free fragment */
+                newblk2 = get_slot(info);
+                newblk2->start = (void *)e;
+                newblk2->size = be - e;
+
+                list_add(&newblk2->list, &blk->list);
+        }
+
+        newblk1 = get_slot(info);
+        newblk1->start = (void *)s;
+        newblk1->size = e - s;
+        newblk1->owner = owner;
+
+        start = newblk1->start;
+        attach_taken_block(info, newblk1);
+
+        return start;
+}
+
+int rh_free(rh_info_t * info, void *start)
+{
+        rh_block_t *blk, *blk2;
+        struct list_head *l;
+        int size;
+
+        /* Linear search for block */
+        blk = NULL;
+        list_for_each(l, &info->taken_list) {
+                blk2 = list_entry(l, rh_block_t, list);
+                if (start < blk2->start)
+                        break;
+                blk = blk2;
+        }
+
+        if (blk == NULL || start > (blk->start + blk->size))
+                return -EINVAL;
+
+        /* Remove from taken list */
+        list_del(&blk->list);
+
+        /* Get size of freed block */
+        size = blk->size;
+        attach_free_block(info, blk);
+
+        return size;
+}
+
+int rh_get_stats(rh_info_t * info, int what, int max_stats, rh_stats_t * stats)
+{
+        rh_block_t *blk;
+        struct list_head *l;
+        struct list_head *h;
+        int nr;
+
+        switch (what) {
+
+        case RHGS_FREE:
+                h = &info->free_list;
+                break;
+
+        case RHGS_TAKEN:
+                h = &info->taken_list;
+                break;
+
+        default:
+                return -EINVAL;
+        }
+
+        /* Linear search for block */
+        nr = 0;
+        list_for_each(l, h) {
+                blk = list_entry(l, rh_block_t, list);
+                if (stats != NULL && nr < max_stats) {
+                        stats->start = blk->start;
+                        stats->size = blk->size;
+                        stats->owner = blk->owner;
+                        stats++;
+                }
+                nr++;
+        }
+
+        return nr;
+}
+
+int rh_set_owner(rh_info_t * info, void *start, const char *owner)
+{
+        rh_block_t *blk, *blk2;
+        struct list_head *l;
+        int size;
+
+        /* Linear search for block */
+        blk = NULL;
+        list_for_each(l, &info->taken_list) {
+                blk2 = list_entry(l, rh_block_t, list);
+                if (start < blk2->start)
+                        break;
+                blk = blk2;
+        }
+
+        if (blk == NULL || start > (blk->start + blk->size))
+                return -EINVAL;
+
+        blk->owner = owner;
+        size = blk->size;
+
+        return size;
+}
+
+void rh_dump(rh_info_t * info)
+{
+        static rh_stats_t st[32];       /* XXX maximum 32 blocks */
+        int maxnr;
+        int i, nr;
+
+        maxnr = sizeof(st) / sizeof(st[0]);
+
+        printk(KERN_INFO
+               "info @0x%p (%d slots empty / %d max)\n",
+               info, info->empty_slots, info->max_blocks);
+
+        printk(KERN_INFO "  Free:\n");
+        nr = rh_get_stats(info, RHGS_FREE, maxnr, st);
+        if (nr > maxnr)
+                nr = maxnr;
+        for (i = 0; i < nr; i++)
+                printk(KERN_INFO
+                       "    0x%p-0x%p (%u)\n",
+                       st[i].start, (int8_t *) st[i].start + st[i].size,
+                       st[i].size);
+        printk(KERN_INFO "\n");
+
+        printk(KERN_INFO "  Taken:\n");
+        nr = rh_get_stats(info, RHGS_TAKEN, maxnr, st);
+        if (nr > maxnr)
+                nr = maxnr;
+        for (i = 0; i < nr; i++)
+                printk(KERN_INFO
+                       "    0x%p-0x%p (%u) %s\n",
+                       st[i].start, (int8_t *) st[i].start + st[i].size,
+                       st[i].size, st[i].owner != NULL ? st[i].owner : "");
+        printk(KERN_INFO "\n");
+}
+
+void rh_dump_blk(rh_info_t * info, rh_block_t * blk)
+{
+        printk(KERN_INFO
+               "blk @0x%p: 0x%p-0x%p (%u)\n",
+               blk, blk->start, (int8_t *) blk->start + blk->size, blk->size);
+}