drivers/base/regmap/regcache-lzo.c - linux - Git at Google

 /*
  * 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 = kcalloc(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_array(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 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);
 	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 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);
 	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 = true;
 		ret = _regmap_write(map, i, val);
 		map->cache_bypass = false;
 		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
 };
	/*
	* 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 = kcalloc(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_array(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 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);
	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 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);
	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 = true;
	ret = _regmap_write(map, i, val);
	map->cache_bypass = false;
	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
	};