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author | Linus Torvalds <torvalds@linux-foundation.org> | 2011-10-25 11:57:45 (GMT) |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2011-10-25 11:57:45 (GMT) |
commit | 4e7e2a2008f5d8c49791c412849d5b0232d39bb3 (patch) | |
tree | 32c3fa2d5cefb388689cb795225022769bf7b413 /drivers/base/regmap/regcache-lzo.c | |
parent | 8a9ea3237e7eb5c25f09e429ad242ae5a3d5ea22 (diff) | |
parent | 7cccbdc84487616c3dbe493b04bfa1f362f4bc56 (diff) | |
download | linux-fsl-qoriq-4e7e2a2008f5d8c49791c412849d5b0232d39bb3.tar.xz |
Merge branch 'for-linus' of git://opensource.wolfsonmicro.com/regmap
* 'for-linus' of git://opensource.wolfsonmicro.com/regmap: (62 commits)
mfd: Enable rbtree cache for wm831x devices
regmap: Support some block operations on cached devices
regmap: Allow caches for devices with no defaults
regmap: Ensure rbtree syncs registers set to zero properly
regmap: Allow rbtree to cache zero default values
regmap: Warn on raw I/O as well as bulk reads that bypass cache
regmap: Return a sensible error code if we fail to read the cache
regmap: Use bsearch() to search the register defaults
regmap: Fix doc comment
regmap: Optimize the lookup path to use binary search
regmap: Ensure we scream if we enable cache bypass/only at the same time
regmap: Implement regcache_cache_bypass helper function
regmap: Save/restore the bypass state upon syncing
regmap: Lock the sync path, ensure we use the lockless _regmap_write()
regmap: Fix apostrophe usage
regmap: Make _regmap_write() global
regmap: Fix lock used for regcache_cache_only()
regmap: Grab the lock in regcache_cache_only()
regmap: Modify map->cache_bypass directly
regmap: Fix regcache_sync generic implementation
...
Diffstat (limited to 'drivers/base/regmap/regcache-lzo.c')
-rw-r--r-- | drivers/base/regmap/regcache-lzo.c | 361 |
1 files changed, 361 insertions, 0 deletions
diff --git a/drivers/base/regmap/regcache-lzo.c b/drivers/base/regmap/regcache-lzo.c new file mode 100644 index 0000000..066aeec --- /dev/null +++ b/drivers/base/regmap/regcache-lzo.c @@ -0,0 +1,361 @@ +/* + * Register cache access API - LZO caching support + * + * Copyright 2011 Wolfson Microelectronics plc + * + * Author: Dimitris Papastamos <dp@opensource.wolfsonmicro.com> + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + */ + +#include <linux/slab.h> +#include <linux/lzo.h> + +#include "internal.h" + +struct regcache_lzo_ctx { + void *wmem; + void *dst; + const void *src; + size_t src_len; + size_t dst_len; + size_t decompressed_size; + unsigned long *sync_bmp; + int sync_bmp_nbits; +}; + +#define LZO_BLOCK_NUM 8 +static int regcache_lzo_block_count(void) +{ + return LZO_BLOCK_NUM; +} + +static int regcache_lzo_prepare(struct regcache_lzo_ctx *lzo_ctx) +{ + lzo_ctx->wmem = kmalloc(LZO1X_MEM_COMPRESS, GFP_KERNEL); + if (!lzo_ctx->wmem) + return -ENOMEM; + return 0; +} + +static int regcache_lzo_compress(struct regcache_lzo_ctx *lzo_ctx) +{ + size_t compress_size; + int ret; + + ret = lzo1x_1_compress(lzo_ctx->src, lzo_ctx->src_len, + lzo_ctx->dst, &compress_size, lzo_ctx->wmem); + if (ret != LZO_E_OK || compress_size > lzo_ctx->dst_len) + return -EINVAL; + lzo_ctx->dst_len = compress_size; + return 0; +} + +static int regcache_lzo_decompress(struct regcache_lzo_ctx *lzo_ctx) +{ + size_t dst_len; + int ret; + + dst_len = lzo_ctx->dst_len; + ret = lzo1x_decompress_safe(lzo_ctx->src, lzo_ctx->src_len, + lzo_ctx->dst, &dst_len); + if (ret != LZO_E_OK || dst_len != lzo_ctx->dst_len) + return -EINVAL; + return 0; +} + +static int regcache_lzo_compress_cache_block(struct regmap *map, + struct regcache_lzo_ctx *lzo_ctx) +{ + int ret; + + lzo_ctx->dst_len = lzo1x_worst_compress(PAGE_SIZE); + lzo_ctx->dst = kmalloc(lzo_ctx->dst_len, GFP_KERNEL); + if (!lzo_ctx->dst) { + lzo_ctx->dst_len = 0; + return -ENOMEM; + } + + ret = regcache_lzo_compress(lzo_ctx); + if (ret < 0) + return ret; + return 0; +} + +static int regcache_lzo_decompress_cache_block(struct regmap *map, + struct regcache_lzo_ctx *lzo_ctx) +{ + int ret; + + lzo_ctx->dst_len = lzo_ctx->decompressed_size; + lzo_ctx->dst = kmalloc(lzo_ctx->dst_len, GFP_KERNEL); + if (!lzo_ctx->dst) { + lzo_ctx->dst_len = 0; + return -ENOMEM; + } + + ret = regcache_lzo_decompress(lzo_ctx); + if (ret < 0) + return ret; + return 0; +} + +static inline int regcache_lzo_get_blkindex(struct regmap *map, + unsigned int reg) +{ + return (reg * map->cache_word_size) / + DIV_ROUND_UP(map->cache_size_raw, regcache_lzo_block_count()); +} + +static inline int regcache_lzo_get_blkpos(struct regmap *map, + unsigned int reg) +{ + return reg % (DIV_ROUND_UP(map->cache_size_raw, regcache_lzo_block_count()) / + map->cache_word_size); +} + +static inline int regcache_lzo_get_blksize(struct regmap *map) +{ + return DIV_ROUND_UP(map->cache_size_raw, regcache_lzo_block_count()); +} + +static int regcache_lzo_init(struct regmap *map) +{ + struct regcache_lzo_ctx **lzo_blocks; + size_t bmp_size; + int ret, i, blksize, blkcount; + const char *p, *end; + unsigned long *sync_bmp; + + ret = 0; + + blkcount = regcache_lzo_block_count(); + map->cache = kzalloc(blkcount * sizeof *lzo_blocks, + GFP_KERNEL); + if (!map->cache) + return -ENOMEM; + lzo_blocks = map->cache; + + /* + * allocate a bitmap to be used when syncing the cache with + * the hardware. Each time a register is modified, the corresponding + * bit is set in the bitmap, so we know that we have to sync + * that register. + */ + bmp_size = map->num_reg_defaults_raw; + sync_bmp = kmalloc(BITS_TO_LONGS(bmp_size) * sizeof(long), + GFP_KERNEL); + if (!sync_bmp) { + ret = -ENOMEM; + goto err; + } + bitmap_zero(sync_bmp, bmp_size); + + /* allocate the lzo blocks and initialize them */ + for (i = 0; i < blkcount; i++) { + lzo_blocks[i] = kzalloc(sizeof **lzo_blocks, + GFP_KERNEL); + if (!lzo_blocks[i]) { + kfree(sync_bmp); + ret = -ENOMEM; + goto err; + } + lzo_blocks[i]->sync_bmp = sync_bmp; + lzo_blocks[i]->sync_bmp_nbits = bmp_size; + /* alloc the working space for the compressed block */ + ret = regcache_lzo_prepare(lzo_blocks[i]); + if (ret < 0) + goto err; + } + + blksize = regcache_lzo_get_blksize(map); + p = map->reg_defaults_raw; + end = map->reg_defaults_raw + map->cache_size_raw; + /* compress the register map and fill the lzo blocks */ + for (i = 0; i < blkcount; i++, p += blksize) { + lzo_blocks[i]->src = p; + if (p + blksize > end) + lzo_blocks[i]->src_len = end - p; + else + lzo_blocks[i]->src_len = blksize; + ret = regcache_lzo_compress_cache_block(map, + lzo_blocks[i]); + if (ret < 0) + goto err; + lzo_blocks[i]->decompressed_size = + lzo_blocks[i]->src_len; + } + + return 0; +err: + regcache_exit(map); + return ret; +} + +static int regcache_lzo_exit(struct regmap *map) +{ + struct regcache_lzo_ctx **lzo_blocks; + int i, blkcount; + + lzo_blocks = map->cache; + if (!lzo_blocks) + return 0; + + blkcount = regcache_lzo_block_count(); + /* + * the pointer to the bitmap used for syncing the cache + * is shared amongst all lzo_blocks. Ensure it is freed + * only once. + */ + if (lzo_blocks[0]) + kfree(lzo_blocks[0]->sync_bmp); + for (i = 0; i < blkcount; i++) { + if (lzo_blocks[i]) { + kfree(lzo_blocks[i]->wmem); + kfree(lzo_blocks[i]->dst); + } + /* each lzo_block is a pointer returned by kmalloc or NULL */ + kfree(lzo_blocks[i]); + } + kfree(lzo_blocks); + map->cache = NULL; + return 0; +} + +static int regcache_lzo_read(struct regmap *map, + unsigned int reg, unsigned int *value) +{ + struct regcache_lzo_ctx *lzo_block, **lzo_blocks; + int ret, blkindex, blkpos; + size_t blksize, tmp_dst_len; + void *tmp_dst; + + /* index of the compressed lzo block */ + blkindex = regcache_lzo_get_blkindex(map, reg); + /* register index within the decompressed block */ + blkpos = regcache_lzo_get_blkpos(map, reg); + /* size of the compressed block */ + blksize = regcache_lzo_get_blksize(map); + lzo_blocks = map->cache; + lzo_block = lzo_blocks[blkindex]; + + /* save the pointer and length of the compressed block */ + tmp_dst = lzo_block->dst; + tmp_dst_len = lzo_block->dst_len; + + /* prepare the source to be the compressed block */ + lzo_block->src = lzo_block->dst; + lzo_block->src_len = lzo_block->dst_len; + + /* decompress the block */ + ret = regcache_lzo_decompress_cache_block(map, lzo_block); + if (ret >= 0) + /* fetch the value from the cache */ + *value = regcache_get_val(lzo_block->dst, blkpos, + map->cache_word_size); + + kfree(lzo_block->dst); + /* restore the pointer and length of the compressed block */ + lzo_block->dst = tmp_dst; + lzo_block->dst_len = tmp_dst_len; + + return ret; +} + +static int regcache_lzo_write(struct regmap *map, + unsigned int reg, unsigned int value) +{ + struct regcache_lzo_ctx *lzo_block, **lzo_blocks; + int ret, blkindex, blkpos; + size_t blksize, tmp_dst_len; + void *tmp_dst; + + /* index of the compressed lzo block */ + blkindex = regcache_lzo_get_blkindex(map, reg); + /* register index within the decompressed block */ + blkpos = regcache_lzo_get_blkpos(map, reg); + /* size of the compressed block */ + blksize = regcache_lzo_get_blksize(map); + lzo_blocks = map->cache; + lzo_block = lzo_blocks[blkindex]; + + /* save the pointer and length of the compressed block */ + tmp_dst = lzo_block->dst; + tmp_dst_len = lzo_block->dst_len; + + /* prepare the source to be the compressed block */ + lzo_block->src = lzo_block->dst; + lzo_block->src_len = lzo_block->dst_len; + + /* decompress the block */ + ret = regcache_lzo_decompress_cache_block(map, lzo_block); + if (ret < 0) { + kfree(lzo_block->dst); + goto out; + } + + /* write the new value to the cache */ + if (regcache_set_val(lzo_block->dst, blkpos, value, + map->cache_word_size)) { + kfree(lzo_block->dst); + goto out; + } + + /* prepare the source to be the decompressed block */ + lzo_block->src = lzo_block->dst; + lzo_block->src_len = lzo_block->dst_len; + + /* compress the block */ + ret = regcache_lzo_compress_cache_block(map, lzo_block); + if (ret < 0) { + kfree(lzo_block->dst); + kfree(lzo_block->src); + goto out; + } + + /* set the bit so we know we have to sync this register */ + set_bit(reg, lzo_block->sync_bmp); + kfree(tmp_dst); + kfree(lzo_block->src); + return 0; +out: + lzo_block->dst = tmp_dst; + lzo_block->dst_len = tmp_dst_len; + return ret; +} + +static int regcache_lzo_sync(struct regmap *map) +{ + struct regcache_lzo_ctx **lzo_blocks; + unsigned int val; + int i; + int ret; + + lzo_blocks = map->cache; + for_each_set_bit(i, lzo_blocks[0]->sync_bmp, lzo_blocks[0]->sync_bmp_nbits) { + ret = regcache_read(map, i, &val); + if (ret) + return ret; + map->cache_bypass = 1; + ret = _regmap_write(map, i, val); + map->cache_bypass = 0; + if (ret) + return ret; + dev_dbg(map->dev, "Synced register %#x, value %#x\n", + i, val); + } + + return 0; +} + +struct regcache_ops regcache_lzo_ops = { + .type = REGCACHE_LZO, + .name = "lzo", + .init = regcache_lzo_init, + .exit = regcache_lzo_exit, + .read = regcache_lzo_read, + .write = regcache_lzo_write, + .sync = regcache_lzo_sync +}; |