diff options
Diffstat (limited to 'arch/powerpc/lib/rheap.c')
| -rw-r--r-- | arch/powerpc/lib/rheap.c | 747 |
1 files changed, 747 insertions, 0 deletions
diff --git a/arch/powerpc/lib/rheap.c b/arch/powerpc/lib/rheap.c new file mode 100644 index 000000000..6aa774aa5 --- /dev/null +++ b/arch/powerpc/lib/rheap.c @@ -0,0 +1,747 @@ +/* + * 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/kernel.h> +#include <linux/export.h> +#include <linux/mm.h> +#include <linux/err.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_array(max_blocks, sizeof(rh_block_t), GFP_ATOMIC); + 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 */ + blk = block + info->max_blocks - new_blocks; + for (i = 0; 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 = 0; + 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 = 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 = 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 && s != (before->start + before->size)) + before = NULL; + + if (after && e != 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 -= 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_ATOMIC); + 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; +} +EXPORT_SYMBOL_GPL(rh_create); + +/* + * 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) + kfree(info->block); + + if ((info->flags & RHIF_STATIC_INFO) == 0) + kfree(info); +} +EXPORT_SYMBOL_GPL(rh_destroy); + +/* + * 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); +} +EXPORT_SYMBOL_GPL(rh_init); + +/* Attach a free memory region, coalesces regions if adjacent */ +int rh_attach_region(rh_info_t * info, unsigned long start, int size) +{ + rh_block_t *blk; + unsigned long s, e, m; + int r; + + /* The region must be aligned */ + s = start; + e = s + size; + m = info->alignment - 1; + + /* Round start up */ + s = (s + m) & ~m; + + /* Round end down */ + e = e & ~m; + + if (IS_ERR_VALUE(e) || (e < s)) + return -ERANGE; + + /* Take final values */ + start = s; + size = 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; +} +EXPORT_SYMBOL_GPL(rh_attach_region); + +/* Detatch given address range, splits free block if needed. */ +unsigned long rh_detach_region(rh_info_t * info, unsigned long 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 (unsigned long) -EINVAL; + + /* The region must be aligned */ + s = 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 (unsigned long) -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 = blk->start; + be = blk->start + blk->size; + if (s >= bs && e <= be) + break; + blk = NULL; + } + + if (blk == NULL) + return (unsigned long) -ENOMEM; + + /* Perfect fit */ + if (bs == s && be == e) { + /* Delete from free list, release slot */ + list_del(&blk->list); + release_slot(info, blk); + return s; + } + + /* blk still in free list, with updated start and/or size */ + if (bs == s || be == e) { + if (bs == s) + 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 = e; + newblk->size = be - e; + + list_add(&newblk->list, &blk->list); + } + + return s; +} +EXPORT_SYMBOL_GPL(rh_detach_region); + +/* Allocate a block of memory at the specified alignment. The value returned + * is an offset into the buffer initialized by rh_init(), or a negative number + * if there is an error. + */ +unsigned long rh_alloc_align(rh_info_t * info, int size, int alignment, const char *owner) +{ + struct list_head *l; + rh_block_t *blk; + rh_block_t *newblk; + unsigned long start, sp_size; + + /* Validate size, and alignment must be power of two */ + if (size <= 0 || (alignment & (alignment - 1)) != 0) + return (unsigned long) -EINVAL; + + /* Align to configured alignment */ + size = (size + (info->alignment - 1)) & ~(info->alignment - 1); + + if (assure_empty(info, 2) < 0) + return (unsigned long) -ENOMEM; + + blk = NULL; + list_for_each(l, &info->free_list) { + blk = list_entry(l, rh_block_t, list); + if (size <= blk->size) { + start = (blk->start + alignment - 1) & ~(alignment - 1); + if (start + size <= blk->start + blk->size) + break; + } + blk = NULL; + } + + if (blk == NULL) + return (unsigned long) -ENOMEM; + + /* Just fits */ + if (blk->size == size) { + /* Move from free list to taken list */ + list_del(&blk->list); + newblk = blk; + } else { + /* Fragment caused, split if needed */ + /* Create block for fragment in the beginning */ + sp_size = start - blk->start; + if (sp_size) { + rh_block_t *spblk; + + spblk = get_slot(info); + spblk->start = blk->start; + spblk->size = sp_size; + /* add before the blk */ + list_add(&spblk->list, blk->list.prev); + } + newblk = get_slot(info); + newblk->start = start; + newblk->size = size; + + /* blk still in free list, with updated start and size + * for fragment in the end */ + blk->start = start + size; + blk->size -= sp_size + size; + /* No fragment in the end, remove blk */ + if (blk->size == 0) { + list_del(&blk->list); + release_slot(info, blk); + } + } + + newblk->owner = owner; + attach_taken_block(info, newblk); + + return start; +} +EXPORT_SYMBOL_GPL(rh_alloc_align); + +/* Allocate a block of memory at the default alignment. The value returned is + * an offset into the buffer initialized by rh_init(), or a negative number if + * there is an error. + */ +unsigned long rh_alloc(rh_info_t * info, int size, const char *owner) +{ + return rh_alloc_align(info, size, info->alignment, owner); +} +EXPORT_SYMBOL_GPL(rh_alloc); + +/* Allocate a block of memory at the given offset, rounded up to the default + * alignment. The value returned is an offset into the buffer initialized by + * rh_init(), or a negative number if there is an error. + */ +unsigned long rh_alloc_fixed(rh_info_t * info, unsigned long start, int size, const char *owner) +{ + struct list_head *l; + rh_block_t *blk, *newblk1, *newblk2; + unsigned long s, e, m, bs = 0, be = 0; + + /* Validate size */ + if (size <= 0) + return (unsigned long) -EINVAL; + + /* The region must be aligned */ + s = 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 (unsigned long) -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 = blk->start; + be = blk->start + blk->size; + if (s >= bs && e <= be) + break; + blk = NULL; + } + + if (blk == NULL) + return (unsigned long) -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 += size; + blk->size -= size; + + } else { + /* The front free fragment */ + blk->size = s - bs; + + /* The back free fragment */ + newblk2 = get_slot(info); + newblk2->start = e; + newblk2->size = be - e; + + list_add(&newblk2->list, &blk->list); + } + + newblk1 = get_slot(info); + newblk1->start = s; + newblk1->size = e - s; + newblk1->owner = owner; + + start = newblk1->start; + attach_taken_block(info, newblk1); + + return start; +} +EXPORT_SYMBOL_GPL(rh_alloc_fixed); + +/* Deallocate the memory previously allocated by one of the rh_alloc functions. + * The return value is the size of the deallocated block, or a negative number + * if there is an error. + */ +int rh_free(rh_info_t * info, unsigned long 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; +} +EXPORT_SYMBOL_GPL(rh_free); + +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; +} +EXPORT_SYMBOL_GPL(rh_get_stats); + +int rh_set_owner(rh_info_t * info, unsigned long 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; +} +EXPORT_SYMBOL_GPL(rh_set_owner); + +void rh_dump(rh_info_t * info) +{ + static rh_stats_t st[32]; /* XXX maximum 32 blocks */ + int maxnr; + int i, nr; + + maxnr = ARRAY_SIZE(st); + + 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%lx-0x%lx (%u)\n", + st[i].start, 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%lx-0x%lx (%u) %s\n", + st[i].start, st[i].start + st[i].size, + st[i].size, st[i].owner != NULL ? st[i].owner : ""); + printk(KERN_INFO "\n"); +} +EXPORT_SYMBOL_GPL(rh_dump); + +void rh_dump_blk(rh_info_t * info, rh_block_t * blk) +{ + printk(KERN_INFO + "blk @0x%p: 0x%lx-0x%lx (%u)\n", + blk, blk->start, blk->start + blk->size, blk->size); +} +EXPORT_SYMBOL_GPL(rh_dump_blk); + |