365 lines
8.7 KiB
C
365 lines
8.7 KiB
C
/*
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* Register cache access API - LZO caching support
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*
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* Copyright 2011 Wolfson Microelectronics plc
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*
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* Author: Dimitris Papastamos <dp@opensource.wolfsonmicro.com>
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*/
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#include <linux/slab.h>
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#include <linux/lzo.h>
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#include "internal.h"
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struct regcache_lzo_ctx {
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void *wmem;
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void *dst;
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const void *src;
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size_t src_len;
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size_t dst_len;
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size_t decompressed_size;
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unsigned long *sync_bmp;
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int sync_bmp_nbits;
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};
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#define LZO_BLOCK_NUM 8
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static int regcache_lzo_block_count(struct regmap *map)
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{
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return LZO_BLOCK_NUM;
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}
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static int regcache_lzo_prepare(struct regcache_lzo_ctx *lzo_ctx)
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{
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lzo_ctx->wmem = kmalloc(LZO1X_MEM_COMPRESS, GFP_KERNEL);
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if (!lzo_ctx->wmem)
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return -ENOMEM;
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return 0;
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}
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static int regcache_lzo_compress(struct regcache_lzo_ctx *lzo_ctx)
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{
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size_t compress_size;
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int ret;
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ret = lzo1x_1_compress(lzo_ctx->src, lzo_ctx->src_len,
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lzo_ctx->dst, &compress_size, lzo_ctx->wmem);
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if (ret != LZO_E_OK || compress_size > lzo_ctx->dst_len)
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return -EINVAL;
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lzo_ctx->dst_len = compress_size;
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return 0;
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}
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static int regcache_lzo_decompress(struct regcache_lzo_ctx *lzo_ctx)
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{
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size_t dst_len;
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int ret;
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dst_len = lzo_ctx->dst_len;
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ret = lzo1x_decompress_safe(lzo_ctx->src, lzo_ctx->src_len,
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lzo_ctx->dst, &dst_len);
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if (ret != LZO_E_OK || dst_len != lzo_ctx->dst_len)
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return -EINVAL;
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return 0;
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}
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static int regcache_lzo_compress_cache_block(struct regmap *map,
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struct regcache_lzo_ctx *lzo_ctx)
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{
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int ret;
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lzo_ctx->dst_len = lzo1x_worst_compress(PAGE_SIZE);
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lzo_ctx->dst = kmalloc(lzo_ctx->dst_len, GFP_KERNEL);
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if (!lzo_ctx->dst) {
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lzo_ctx->dst_len = 0;
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return -ENOMEM;
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}
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ret = regcache_lzo_compress(lzo_ctx);
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if (ret < 0)
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return ret;
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return 0;
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}
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static int regcache_lzo_decompress_cache_block(struct regmap *map,
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struct regcache_lzo_ctx *lzo_ctx)
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{
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int ret;
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lzo_ctx->dst_len = lzo_ctx->decompressed_size;
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lzo_ctx->dst = kmalloc(lzo_ctx->dst_len, GFP_KERNEL);
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if (!lzo_ctx->dst) {
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lzo_ctx->dst_len = 0;
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return -ENOMEM;
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}
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ret = regcache_lzo_decompress(lzo_ctx);
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if (ret < 0)
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return ret;
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return 0;
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}
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static inline int regcache_lzo_get_blkindex(struct regmap *map,
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unsigned int reg)
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{
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return (reg * map->cache_word_size) /
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DIV_ROUND_UP(map->cache_size_raw,
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regcache_lzo_block_count(map));
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}
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static inline int regcache_lzo_get_blkpos(struct regmap *map,
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unsigned int reg)
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{
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return reg % (DIV_ROUND_UP(map->cache_size_raw,
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regcache_lzo_block_count(map)) /
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map->cache_word_size);
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}
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static inline int regcache_lzo_get_blksize(struct regmap *map)
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{
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return DIV_ROUND_UP(map->cache_size_raw,
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regcache_lzo_block_count(map));
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}
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static int regcache_lzo_init(struct regmap *map)
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{
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struct regcache_lzo_ctx **lzo_blocks;
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size_t bmp_size;
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int ret, i, blksize, blkcount;
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const char *p, *end;
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unsigned long *sync_bmp;
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ret = 0;
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blkcount = regcache_lzo_block_count(map);
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map->cache = kzalloc(blkcount * sizeof *lzo_blocks,
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GFP_KERNEL);
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if (!map->cache)
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return -ENOMEM;
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lzo_blocks = map->cache;
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/*
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* allocate a bitmap to be used when syncing the cache with
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* the hardware. Each time a register is modified, the corresponding
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* bit is set in the bitmap, so we know that we have to sync
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* that register.
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*/
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bmp_size = map->num_reg_defaults_raw;
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sync_bmp = kmalloc(BITS_TO_LONGS(bmp_size) * sizeof(long),
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GFP_KERNEL);
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if (!sync_bmp) {
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ret = -ENOMEM;
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goto err;
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}
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bitmap_zero(sync_bmp, bmp_size);
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/* allocate the lzo blocks and initialize them */
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for (i = 0; i < blkcount; i++) {
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lzo_blocks[i] = kzalloc(sizeof **lzo_blocks,
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GFP_KERNEL);
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if (!lzo_blocks[i]) {
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kfree(sync_bmp);
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ret = -ENOMEM;
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goto err;
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}
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lzo_blocks[i]->sync_bmp = sync_bmp;
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lzo_blocks[i]->sync_bmp_nbits = bmp_size;
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/* alloc the working space for the compressed block */
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ret = regcache_lzo_prepare(lzo_blocks[i]);
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if (ret < 0)
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goto err;
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}
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blksize = regcache_lzo_get_blksize(map);
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p = map->reg_defaults_raw;
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end = map->reg_defaults_raw + map->cache_size_raw;
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/* compress the register map and fill the lzo blocks */
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for (i = 0; i < blkcount; i++, p += blksize) {
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lzo_blocks[i]->src = p;
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if (p + blksize > end)
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lzo_blocks[i]->src_len = end - p;
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else
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lzo_blocks[i]->src_len = blksize;
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ret = regcache_lzo_compress_cache_block(map,
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lzo_blocks[i]);
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if (ret < 0)
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goto err;
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lzo_blocks[i]->decompressed_size =
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lzo_blocks[i]->src_len;
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}
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return 0;
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err:
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regcache_exit(map);
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return ret;
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}
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static int regcache_lzo_exit(struct regmap *map)
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{
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struct regcache_lzo_ctx **lzo_blocks;
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int i, blkcount;
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lzo_blocks = map->cache;
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if (!lzo_blocks)
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return 0;
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blkcount = regcache_lzo_block_count(map);
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/*
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* the pointer to the bitmap used for syncing the cache
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* is shared amongst all lzo_blocks. Ensure it is freed
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* only once.
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*/
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if (lzo_blocks[0])
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kfree(lzo_blocks[0]->sync_bmp);
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for (i = 0; i < blkcount; i++) {
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if (lzo_blocks[i]) {
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kfree(lzo_blocks[i]->wmem);
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kfree(lzo_blocks[i]->dst);
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}
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/* each lzo_block is a pointer returned by kmalloc or NULL */
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kfree(lzo_blocks[i]);
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}
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kfree(lzo_blocks);
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map->cache = NULL;
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return 0;
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}
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static int regcache_lzo_read(struct regmap *map,
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unsigned int reg, unsigned int *value)
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{
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struct regcache_lzo_ctx *lzo_block, **lzo_blocks;
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int ret, blkindex, blkpos;
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size_t blksize, tmp_dst_len;
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void *tmp_dst;
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/* index of the compressed lzo block */
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blkindex = regcache_lzo_get_blkindex(map, reg);
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/* register index within the decompressed block */
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blkpos = regcache_lzo_get_blkpos(map, reg);
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/* size of the compressed block */
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blksize = regcache_lzo_get_blksize(map);
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lzo_blocks = map->cache;
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lzo_block = lzo_blocks[blkindex];
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/* save the pointer and length of the compressed block */
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tmp_dst = lzo_block->dst;
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tmp_dst_len = lzo_block->dst_len;
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/* prepare the source to be the compressed block */
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lzo_block->src = lzo_block->dst;
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lzo_block->src_len = lzo_block->dst_len;
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/* decompress the block */
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ret = regcache_lzo_decompress_cache_block(map, lzo_block);
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if (ret >= 0)
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/* fetch the value from the cache */
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*value = regcache_get_val(lzo_block->dst, blkpos,
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map->cache_word_size);
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kfree(lzo_block->dst);
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/* restore the pointer and length of the compressed block */
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lzo_block->dst = tmp_dst;
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lzo_block->dst_len = tmp_dst_len;
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return ret;
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}
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static int regcache_lzo_write(struct regmap *map,
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unsigned int reg, unsigned int value)
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{
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struct regcache_lzo_ctx *lzo_block, **lzo_blocks;
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int ret, blkindex, blkpos;
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size_t blksize, tmp_dst_len;
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void *tmp_dst;
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/* index of the compressed lzo block */
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blkindex = regcache_lzo_get_blkindex(map, reg);
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/* register index within the decompressed block */
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blkpos = regcache_lzo_get_blkpos(map, reg);
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/* size of the compressed block */
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blksize = regcache_lzo_get_blksize(map);
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lzo_blocks = map->cache;
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lzo_block = lzo_blocks[blkindex];
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/* save the pointer and length of the compressed block */
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tmp_dst = lzo_block->dst;
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tmp_dst_len = lzo_block->dst_len;
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/* prepare the source to be the compressed block */
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lzo_block->src = lzo_block->dst;
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lzo_block->src_len = lzo_block->dst_len;
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/* decompress the block */
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ret = regcache_lzo_decompress_cache_block(map, lzo_block);
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if (ret < 0) {
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kfree(lzo_block->dst);
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goto out;
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}
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/* write the new value to the cache */
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if (regcache_set_val(lzo_block->dst, blkpos, value,
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map->cache_word_size)) {
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kfree(lzo_block->dst);
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goto out;
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}
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/* prepare the source to be the decompressed block */
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lzo_block->src = lzo_block->dst;
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lzo_block->src_len = lzo_block->dst_len;
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/* compress the block */
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ret = regcache_lzo_compress_cache_block(map, lzo_block);
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if (ret < 0) {
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kfree(lzo_block->dst);
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kfree(lzo_block->src);
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goto out;
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}
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/* set the bit so we know we have to sync this register */
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set_bit(reg, lzo_block->sync_bmp);
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kfree(tmp_dst);
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kfree(lzo_block->src);
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return 0;
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out:
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lzo_block->dst = tmp_dst;
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lzo_block->dst_len = tmp_dst_len;
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return ret;
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}
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static int regcache_lzo_sync(struct regmap *map)
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{
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struct regcache_lzo_ctx **lzo_blocks;
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unsigned int val;
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int i;
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int ret;
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lzo_blocks = map->cache;
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for_each_set_bit(i, lzo_blocks[0]->sync_bmp, lzo_blocks[0]->sync_bmp_nbits) {
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ret = regcache_read(map, i, &val);
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if (ret)
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return ret;
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map->cache_bypass = 1;
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ret = _regmap_write(map, i, val);
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map->cache_bypass = 0;
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if (ret)
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return ret;
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dev_dbg(map->dev, "Synced register %#x, value %#x\n",
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i, val);
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}
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return 0;
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}
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struct regcache_ops regcache_lzo_ops = {
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.type = REGCACHE_COMPRESSED,
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.name = "lzo",
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.init = regcache_lzo_init,
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.exit = regcache_lzo_exit,
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.read = regcache_lzo_read,
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.write = regcache_lzo_write,
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.sync = regcache_lzo_sync
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};
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