| /* |
| * 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" |
| |
| static int regcache_lzo_exit(struct regmap *map); |
| |
| 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(struct regmap *map) |
| { |
| 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(map)); |
| } |
| |
| 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)) / |
| 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(map)); |
| } |
| |
| 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); |
| 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_lzo_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(map); |
| /* |
| * 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, unsigned int min, |
| unsigned int max) |
| { |
| struct regcache_lzo_ctx **lzo_blocks; |
| unsigned int val; |
| int i; |
| int ret; |
| |
| lzo_blocks = map->cache; |
| i = min; |
| for_each_set_bit_from(i, lzo_blocks[0]->sync_bmp, |
| lzo_blocks[0]->sync_bmp_nbits) { |
| if (i > max) |
| continue; |
| |
| ret = regcache_read(map, i, &val); |
| if (ret) |
| return ret; |
| |
| /* Is this the hardware default? If so skip. */ |
| ret = regcache_lookup_reg(map, i); |
| if (ret > 0 && val == map->reg_defaults[ret].def) |
| continue; |
| |
| 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_COMPRESSED, |
| .name = "lzo", |
| .init = regcache_lzo_init, |
| .exit = regcache_lzo_exit, |
| .read = regcache_lzo_read, |
| .write = regcache_lzo_write, |
| .sync = regcache_lzo_sync |
| }; |