--- /dev/null
+/*
+ * 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/device.h>
+#include <linux/lzo.h>
+#include <linux/slab.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(map, lzo_block->dst, blkpos);
+
+ 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(map, lzo_block->dst, blkpos, value)) {
+ 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
+};
Code Review / kvmfornfv.git / blobdiff