|  | /* | 
|  | * 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/device.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->reg_stride) * 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 / map->reg_stride) % | 
|  | (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 / map->reg_stride, 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 | 
|  | }; |