[deliverable/linux.git] / drivers / base / regmap / regcache-rbtree.c

/*
 * Register cache access API - rbtree 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/debugfs.h>
#include <linux/rbtree.h>
#include <linux/seq_file.h>

#include "internal.h"

static int regcache_rbtree_write(struct regmap *map, unsigned int reg,
				 unsigned int value);
static int regcache_rbtree_exit(struct regmap *map);

struct regcache_rbtree_node {
	/* the actual rbtree node holding this block */
	struct rb_node node;
	/* base register handled by this block */
	unsigned int base_reg;
	/* block of adjacent registers */
	void *block;
	/* number of registers available in the block */
	unsigned int blklen;
} __attribute__ ((packed));

struct regcache_rbtree_ctx {
	struct rb_root root;
	struct regcache_rbtree_node *cached_rbnode;
};

static inline void regcache_rbtree_get_base_top_reg(
	struct regmap *map,
	struct regcache_rbtree_node *rbnode,
	unsigned int *base, unsigned int *top)
{
	*base = rbnode->base_reg;
	*top = rbnode->base_reg + ((rbnode->blklen - 1) * map->reg_stride);
}

static unsigned int regcache_rbtree_get_register(struct regmap *map,
	struct regcache_rbtree_node *rbnode, unsigned int idx)
{
	return regcache_get_val(map, rbnode->block, idx);
}

static void regcache_rbtree_set_register(struct regmap *map,
					 struct regcache_rbtree_node *rbnode,
					 unsigned int idx, unsigned int val)
{
	regcache_set_val(map, rbnode->block, idx, val);
}

static struct regcache_rbtree_node *regcache_rbtree_lookup(struct regmap *map,
							   unsigned int reg)
{
	struct regcache_rbtree_ctx *rbtree_ctx = map->cache;
	struct rb_node *node;
	struct regcache_rbtree_node *rbnode;
	unsigned int base_reg, top_reg;

	rbnode = rbtree_ctx->cached_rbnode;
	if (rbnode) {
		regcache_rbtree_get_base_top_reg(map, rbnode, &base_reg,
						 &top_reg);
		if (reg >= base_reg && reg <= top_reg)
			return rbnode;
	}

	node = rbtree_ctx->root.rb_node;
	while (node) {
		rbnode = container_of(node, struct regcache_rbtree_node, node);
		regcache_rbtree_get_base_top_reg(map, rbnode, &base_reg,
						 &top_reg);
		if (reg >= base_reg && reg <= top_reg) {
			rbtree_ctx->cached_rbnode = rbnode;
			return rbnode;
		} else if (reg > top_reg) {
			node = node->rb_right;
		} else if (reg < base_reg) {
			node = node->rb_left;
		}
	}

	return NULL;
}

static int regcache_rbtree_insert(struct regmap *map, struct rb_root *root,
				  struct regcache_rbtree_node *rbnode)
{
	struct rb_node **new, *parent;
	struct regcache_rbtree_node *rbnode_tmp;
	unsigned int base_reg_tmp, top_reg_tmp;
	unsigned int base_reg;

	parent = NULL;
	new = &root->rb_node;
	while (*new) {
		rbnode_tmp = container_of(*new, struct regcache_rbtree_node,
					  node);
		/* base and top registers of the current rbnode */
		regcache_rbtree_get_base_top_reg(map, rbnode_tmp, &base_reg_tmp,
						 &top_reg_tmp);
		/* base register of the rbnode to be added */
		base_reg = rbnode->base_reg;
		parent = *new;
		/* if this register has already been inserted, just return */
		if (base_reg >= base_reg_tmp &&
		    base_reg <= top_reg_tmp)
			return 0;
		else if (base_reg > top_reg_tmp)
			new = &((*new)->rb_right);
		else if (base_reg < base_reg_tmp)
			new = &((*new)->rb_left);
	}

	/* insert the node into the rbtree */
	rb_link_node(&rbnode->node, parent, new);
	rb_insert_color(&rbnode->node, root);

	return 1;
}

#ifdef CONFIG_DEBUG_FS
static int rbtree_show(struct seq_file *s, void *ignored)
{
	struct regmap *map = s->private;
	struct regcache_rbtree_ctx *rbtree_ctx = map->cache;
	struct regcache_rbtree_node *n;
	struct rb_node *node;
	unsigned int base, top;
	size_t mem_size;
	int nodes = 0;
	int registers = 0;
	int this_registers, average;

	map->lock(map->lock_arg);

	mem_size = sizeof(*rbtree_ctx);
	mem_size += BITS_TO_LONGS(map->cache_present_nbits) * sizeof(long);

	for (node = rb_first(&rbtree_ctx->root); node != NULL;
	     node = rb_next(node)) {
		n = container_of(node, struct regcache_rbtree_node, node);
		mem_size += sizeof(*n);
		mem_size += (n->blklen * map->cache_word_size);

		regcache_rbtree_get_base_top_reg(map, n, &base, &top);
		this_registers = ((top - base) / map->reg_stride) + 1;
		seq_printf(s, "%x-%x (%d)\n", base, top, this_registers);

		nodes++;
		registers += this_registers;
	}

	if (nodes)
		average = registers / nodes;
	else
		average = 0;

	seq_printf(s, "%d nodes, %d registers, average %d registers, used %zu bytes\n",
		   nodes, registers, average, mem_size);

	map->unlock(map->lock_arg);

	return 0;
}

static int rbtree_open(struct inode *inode, struct file *file)
{
	return single_open(file, rbtree_show, inode->i_private);
}

static const struct file_operations rbtree_fops = {
	.open		= rbtree_open,
	.read		= seq_read,
	.llseek		= seq_lseek,
	.release	= single_release,
};

static void rbtree_debugfs_init(struct regmap *map)
{
	debugfs_create_file("rbtree", 0400, map->debugfs, map, &rbtree_fops);
}
#else
static void rbtree_debugfs_init(struct regmap *map)
{
}
#endif

static int regcache_rbtree_init(struct regmap *map)
{
	struct regcache_rbtree_ctx *rbtree_ctx;
	int i;
	int ret;

	map->cache = kmalloc(sizeof *rbtree_ctx, GFP_KERNEL);
	if (!map->cache)
		return -ENOMEM;

	rbtree_ctx = map->cache;
	rbtree_ctx->root = RB_ROOT;
	rbtree_ctx->cached_rbnode = NULL;

	for (i = 0; i < map->num_reg_defaults; i++) {
		ret = regcache_rbtree_write(map,
					    map->reg_defaults[i].reg,
					    map->reg_defaults[i].def);
		if (ret)
			goto err;
	}

	rbtree_debugfs_init(map);

	return 0;

err:
	regcache_rbtree_exit(map);
	return ret;
}

static int regcache_rbtree_exit(struct regmap *map)
{
	struct rb_node *next;
	struct regcache_rbtree_ctx *rbtree_ctx;
	struct regcache_rbtree_node *rbtree_node;

	/* if we've already been called then just return */
	rbtree_ctx = map->cache;
	if (!rbtree_ctx)
		return 0;

	/* free up the rbtree */
	next = rb_first(&rbtree_ctx->root);
	while (next) {
		rbtree_node = rb_entry(next, struct regcache_rbtree_node, node);
		next = rb_next(&rbtree_node->node);
		rb_erase(&rbtree_node->node, &rbtree_ctx->root);
		kfree(rbtree_node->block);
		kfree(rbtree_node);
	}

	/* release the resources */
	kfree(map->cache);
	map->cache = NULL;

	return 0;
}

static int regcache_rbtree_read(struct regmap *map,
				unsigned int reg, unsigned int *value)
{
	struct regcache_rbtree_node *rbnode;
	unsigned int reg_tmp;

	rbnode = regcache_rbtree_lookup(map, reg);
	if (rbnode) {
		reg_tmp = (reg - rbnode->base_reg) / map->reg_stride;
		if (!regcache_reg_present(map, reg))
			return -ENOENT;
		*value = regcache_rbtree_get_register(map, rbnode, reg_tmp);
	} else {
		return -ENOENT;
	}

	return 0;
}


static int regcache_rbtree_insert_to_block(struct regmap *map,
					   struct regcache_rbtree_node *rbnode,
					   unsigned int base_reg,
					   unsigned int top_reg,
					   unsigned int reg,
					   unsigned int value)
{
	unsigned int blklen;
	unsigned int pos, offset;
	u8 *blk;

	blklen = (top_reg - base_reg) / map->reg_stride + 1;
	pos = (reg - base_reg) / map->reg_stride;
	offset = (rbnode->base_reg - base_reg) / map->reg_stride;

	blk = krealloc(rbnode->block,
		       blklen * map->cache_word_size,
		       GFP_KERNEL);
	if (!blk)
		return -ENOMEM;

	/* insert the register value in the correct place in the rbnode block */
	if (pos == 0)
		memmove(blk + offset * map->cache_word_size,
			blk, rbnode->blklen * map->cache_word_size);

	/* update the rbnode block, its size and the base register */
	rbnode->block = blk;
	rbnode->blklen = blklen;
	rbnode->base_reg = base_reg;

	regcache_rbtree_set_register(map, rbnode, pos, value);
	return 0;
}

static struct regcache_rbtree_node *
regcache_rbtree_node_alloc(struct regmap *map, unsigned int reg)
{
	struct regcache_rbtree_node *rbnode;
	const struct regmap_range *range;
	int i;

	rbnode = kzalloc(sizeof(*rbnode), GFP_KERNEL);
	if (!rbnode)
		return NULL;

	/* If there is a read table then use it to guess at an allocation */
	if (map->rd_table) {
		for (i = 0; i < map->rd_table->n_yes_ranges; i++) {
			if (regmap_reg_in_range(reg,
						&map->rd_table->yes_ranges[i]))
				break;
		}

		if (i != map->rd_table->n_yes_ranges) {
			range = &map->rd_table->yes_ranges[i];
			rbnode->blklen = (range->range_max - range->range_min) /
				map->reg_stride	+ 1;
			rbnode->base_reg = range->range_min;
		}
	}

	if (!rbnode->blklen) {
		rbnode->blklen = sizeof(*rbnode);
		rbnode->base_reg = reg;
	}

	rbnode->block = kmalloc(rbnode->blklen * map->cache_word_size,
				GFP_KERNEL);
	if (!rbnode->block) {
		kfree(rbnode);
		return NULL;
	}

	return rbnode;
}

static int regcache_rbtree_write(struct regmap *map, unsigned int reg,
				 unsigned int value)
{
	struct regcache_rbtree_ctx *rbtree_ctx;
	struct regcache_rbtree_node *rbnode, *rbnode_tmp;
	struct rb_node *node;
	unsigned int reg_tmp;
	int ret;

	rbtree_ctx = map->cache;
	/* update the reg_present bitmap, make space if necessary */
	ret = regcache_set_reg_present(map, reg);
	if (ret < 0)
		return ret;

	/* if we can't locate it in the cached rbnode we'll have
	 * to traverse the rbtree looking for it.
	 */
	rbnode = regcache_rbtree_lookup(map, reg);
	if (rbnode) {
		reg_tmp = (reg - rbnode->base_reg) / map->reg_stride;
		regcache_rbtree_set_register(map, rbnode, reg_tmp, value);
	} else {
		unsigned int base_reg, top_reg;
		unsigned int new_base_reg, new_top_reg;
		unsigned int min, max;
		unsigned int max_dist;

		max_dist = map->reg_stride * sizeof(*rbnode_tmp) /
			map->cache_word_size;
		if (reg < max_dist)
			min = 0;
		else
			min = reg - max_dist;
		max = reg + max_dist;

		/* look for an adjacent register to the one we are about to add */
		for (node = rb_first(&rbtree_ctx->root); node;
		     node = rb_next(node)) {
			rbnode_tmp = rb_entry(node, struct regcache_rbtree_node,
					      node);

			regcache_rbtree_get_base_top_reg(map, rbnode_tmp,
				&base_reg, &top_reg);

			if (base_reg <= max && top_reg >= min) {
				new_base_reg = min(reg, base_reg);
				new_top_reg = max(reg, top_reg);
			} else {
				continue;
			}

			ret = regcache_rbtree_insert_to_block(map, rbnode_tmp,
							      new_base_reg,
							      new_top_reg, reg,
							      value);
			if (ret)
				return ret;
			rbtree_ctx->cached_rbnode = rbnode_tmp;
			return 0;
		}

		/* We did not manage to find a place to insert it in
		 * an existing block so create a new rbnode.
		 */
		rbnode = regcache_rbtree_node_alloc(map, reg);
		if (!rbnode)
			return -ENOMEM;
		regcache_rbtree_set_register(map, rbnode,
					     reg - rbnode->base_reg, value);
		regcache_rbtree_insert(map, &rbtree_ctx->root, rbnode);
		rbtree_ctx->cached_rbnode = rbnode;
	}

	return 0;
}

static int regcache_rbtree_sync(struct regmap *map, unsigned int min,
				unsigned int max)
{
	struct regcache_rbtree_ctx *rbtree_ctx;
	struct rb_node *node;
	struct regcache_rbtree_node *rbnode;
	unsigned int base_reg, top_reg;
	unsigned int start, end;
	int ret;

	rbtree_ctx = map->cache;
	for (node = rb_first(&rbtree_ctx->root); node; node = rb_next(node)) {
		rbnode = rb_entry(node, struct regcache_rbtree_node, node);

		regcache_rbtree_get_base_top_reg(map, rbnode, &base_reg,
			&top_reg);
		if (base_reg > max)
			break;
		if (top_reg < min)
			continue;

		if (min > base_reg)
			start = (min - base_reg) / map->reg_stride;
		else
			start = 0;

		if (max < top_reg)
			end = (max - base_reg) / map->reg_stride + 1;
		else
			end = rbnode->blklen;

		ret = regcache_sync_block(map, rbnode->block, rbnode->base_reg,
					  start, end);
		if (ret != 0)
			return ret;
	}

	return regmap_async_complete(map);
}

struct regcache_ops regcache_rbtree_ops = {
	.type = REGCACHE_RBTREE,
	.name = "rbtree",
	.init = regcache_rbtree_init,
	.exit = regcache_rbtree_exit,
	.read = regcache_rbtree_read,
	.write = regcache_rbtree_write,
	.sync = regcache_rbtree_sync
};
Commit	Line	Data
28644c80 DP	1	/*
	2	* Register cache access API - rbtree caching support
	3	*
	4	* Copyright 2011 Wolfson Microelectronics plc
	5	*
	6	* Author: Dimitris Papastamos <dp@opensource.wolfsonmicro.com>
	7	*
	8	* This program is free software; you can redistribute it and/or modify
	9	* it under the terms of the GNU General Public License version 2 as
	10	* published by the Free Software Foundation.
	11	*/
	12
	13	#include <linux/slab.h>
51990e82	14	#include <linux/device.h>
bad2ab4b	15	#include <linux/debugfs.h>
28644c80	16	#include <linux/rbtree.h>
bad2ab4b	17	#include <linux/seq_file.h>
28644c80 DP	18
	19	#include "internal.h"
	20
	21	static int regcache_rbtree_write(struct regmap *map, unsigned int reg,
	22	unsigned int value);
462a185c	23	static int regcache_rbtree_exit(struct regmap *map);
28644c80 DP	24
	25	struct regcache_rbtree_node {
	26	/* the actual rbtree node holding this block */
	27	struct rb_node node;
	28	/* base register handled by this block */
	29	unsigned int base_reg;
28644c80 DP	30	/* block of adjacent registers */
	31	void *block;
	32	/* number of registers available in the block */
	33	unsigned int blklen;
	34	} __attribute__ ((packed));
	35
	36	struct regcache_rbtree_ctx {
	37	struct rb_root root;
	38	struct regcache_rbtree_node *cached_rbnode;
	39	};
	40
	41	static inline void regcache_rbtree_get_base_top_reg(
f01ee60f	42	struct regmap *map,
28644c80 DP	43	struct regcache_rbtree_node *rbnode,
	44	unsigned int base, unsigned int top)
	45	{
	46	*base = rbnode->base_reg;
f01ee60f	47	top = rbnode->base_reg + ((rbnode->blklen - 1) map->reg_stride);
28644c80 DP	48	}
28644c80 DP	49
879082c9 MB	50	static unsigned int regcache_rbtree_get_register(struct regmap *map,
879082c9 MB	51	struct regcache_rbtree_node *rbnode, unsigned int idx)
28644c80	52	{
879082c9	53	return regcache_get_val(map, rbnode->block, idx);
28644c80 DP	54	}
28644c80 DP	55
879082c9 MB	56	static void regcache_rbtree_set_register(struct regmap *map,
	57	struct regcache_rbtree_node *rbnode,
	58	unsigned int idx, unsigned int val)
28644c80	59	{
879082c9	60	regcache_set_val(map, rbnode->block, idx, val);
28644c80 DP	61	}
28644c80 DP	62
3405addd	63	static struct regcache_rbtree_node regcache_rbtree_lookup(struct regmap map,
879082c9	64	unsigned int reg)
28644c80	65	{
3405addd	66	struct regcache_rbtree_ctx *rbtree_ctx = map->cache;
28644c80 DP	67	struct rb_node *node;
	68	struct regcache_rbtree_node *rbnode;
	69	unsigned int base_reg, top_reg;
	70
3405addd LPC	71	rbnode = rbtree_ctx->cached_rbnode;
3405addd LPC	72	if (rbnode) {
f01ee60f SW	73	regcache_rbtree_get_base_top_reg(map, rbnode, &base_reg,
f01ee60f SW	74	&top_reg);
3405addd LPC	75	if (reg >= base_reg && reg <= top_reg)
	76	return rbnode;
	77	}
	78
	79	node = rbtree_ctx->root.rb_node;
28644c80 DP	80	while (node) {
28644c80 DP	81	rbnode = container_of(node, struct regcache_rbtree_node, node);
f01ee60f SW	82	regcache_rbtree_get_base_top_reg(map, rbnode, &base_reg,
f01ee60f SW	83	&top_reg);
3405addd LPC	84	if (reg >= base_reg && reg <= top_reg) {
3405addd LPC	85	rbtree_ctx->cached_rbnode = rbnode;
28644c80	86	return rbnode;
3405addd	87	} else if (reg > top_reg) {
28644c80	88	node = node->rb_right;
3405addd	89	} else if (reg < base_reg) {
28644c80	90	node = node->rb_left;
3405addd	91	}
28644c80 DP	92	}
	93
	94	return NULL;
	95	}
	96
f01ee60f	97	static int regcache_rbtree_insert(struct regmap map, struct rb_root root,
28644c80 DP	98	struct regcache_rbtree_node *rbnode)
	99	{
	100	struct rb_node *new, parent;
	101	struct regcache_rbtree_node *rbnode_tmp;
	102	unsigned int base_reg_tmp, top_reg_tmp;
	103	unsigned int base_reg;
	104
	105	parent = NULL;
	106	new = &root->rb_node;
	107	while (*new) {
	108	rbnode_tmp = container_of(*new, struct regcache_rbtree_node,
	109	node);
	110	/* base and top registers of the current rbnode */
f01ee60f	111	regcache_rbtree_get_base_top_reg(map, rbnode_tmp, &base_reg_tmp,
28644c80 DP	112	&top_reg_tmp);
	113	/* base register of the rbnode to be added */
	114	base_reg = rbnode->base_reg;
	115	parent = *new;
	116	/* if this register has already been inserted, just return */
	117	if (base_reg >= base_reg_tmp &&
	118	base_reg <= top_reg_tmp)
	119	return 0;
	120	else if (base_reg > top_reg_tmp)
	121	new = &((*new)->rb_right);
	122	else if (base_reg < base_reg_tmp)
	123	new = &((*new)->rb_left);
	124	}
	125
	126	/* insert the node into the rbtree */
	127	rb_link_node(&rbnode->node, parent, new);
	128	rb_insert_color(&rbnode->node, root);
	129
	130	return 1;
	131	}
	132
bad2ab4b MB	133	#ifdef CONFIG_DEBUG_FS
	134	static int rbtree_show(struct seq_file s, void ignored)
	135	{
	136	struct regmap *map = s->private;
	137	struct regcache_rbtree_ctx *rbtree_ctx = map->cache;
	138	struct regcache_rbtree_node *n;
	139	struct rb_node *node;
	140	unsigned int base, top;
a42277c7	141	size_t mem_size;
bad2ab4b MB	142	int nodes = 0;
bad2ab4b MB	143	int registers = 0;
f01ee60f	144	int this_registers, average;
bad2ab4b	145
f20c783c	146	map->lock(map->lock_arg);
bad2ab4b	147
a42277c7	148	mem_size = sizeof(*rbtree_ctx);
78493f2d	149	mem_size += BITS_TO_LONGS(map->cache_present_nbits) * sizeof(long);
a42277c7	150
bad2ab4b MB	151	for (node = rb_first(&rbtree_ctx->root); node != NULL;
	152	node = rb_next(node)) {
	153	n = container_of(node, struct regcache_rbtree_node, node);
a42277c7 DP	154	mem_size += sizeof(*n);
a42277c7 DP	155	mem_size += (n->blklen * map->cache_word_size);
bad2ab4b	156
f01ee60f SW	157	regcache_rbtree_get_base_top_reg(map, n, &base, &top);
	158	this_registers = ((top - base) / map->reg_stride) + 1;
	159	seq_printf(s, "%x-%x (%d)\n", base, top, this_registers);
bad2ab4b MB	160
bad2ab4b MB	161	nodes++;
f01ee60f	162	registers += this_registers;
bad2ab4b MB	163	}
bad2ab4b MB	164
c04c1b9e SW	165	if (nodes)
	166	average = registers / nodes;
	167	else
	168	average = 0;
	169
a42277c7 DP	170	seq_printf(s, "%d nodes, %d registers, average %d registers, used %zu bytes\n",
a42277c7 DP	171	nodes, registers, average, mem_size);
bad2ab4b	172
f20c783c	173	map->unlock(map->lock_arg);
bad2ab4b MB	174
	175	return 0;
	176	}
	177
	178	static int rbtree_open(struct inode inode, struct file file)
	179	{
	180	return single_open(file, rbtree_show, inode->i_private);
	181	}
	182
	183	static const struct file_operations rbtree_fops = {
	184	.open = rbtree_open,
	185	.read = seq_read,
	186	.llseek = seq_lseek,
	187	.release = single_release,
	188	};
cce585ce MB	189
	190	static void rbtree_debugfs_init(struct regmap *map)
	191	{
	192	debugfs_create_file("rbtree", 0400, map->debugfs, map, &rbtree_fops);
	193	}
	194	#else
	195	static void rbtree_debugfs_init(struct regmap *map)
	196	{
	197	}
bad2ab4b MB	198	#endif
bad2ab4b MB	199
28644c80 DP	200	static int regcache_rbtree_init(struct regmap *map)
	201	{
	202	struct regcache_rbtree_ctx *rbtree_ctx;
	203	int i;
	204	int ret;
	205
	206	map->cache = kmalloc(sizeof *rbtree_ctx, GFP_KERNEL);
	207	if (!map->cache)
	208	return -ENOMEM;
	209
	210	rbtree_ctx = map->cache;
	211	rbtree_ctx->root = RB_ROOT;
	212	rbtree_ctx->cached_rbnode = NULL;
	213
	214	for (i = 0; i < map->num_reg_defaults; i++) {
	215	ret = regcache_rbtree_write(map,
	216	map->reg_defaults[i].reg,
	217	map->reg_defaults[i].def);
	218	if (ret)
	219	goto err;
	220	}
	221
cce585ce	222	rbtree_debugfs_init(map);
bad2ab4b	223
28644c80 DP	224	return 0;
	225
	226	err:
462a185c	227	regcache_rbtree_exit(map);
28644c80 DP	228	return ret;
	229	}
	230
	231	static int regcache_rbtree_exit(struct regmap *map)
	232	{
	233	struct rb_node *next;
	234	struct regcache_rbtree_ctx *rbtree_ctx;
	235	struct regcache_rbtree_node *rbtree_node;
	236
	237	/* if we've already been called then just return */
	238	rbtree_ctx = map->cache;
	239	if (!rbtree_ctx)
	240	return 0;
	241
	242	/* free up the rbtree */
	243	next = rb_first(&rbtree_ctx->root);
	244	while (next) {
	245	rbtree_node = rb_entry(next, struct regcache_rbtree_node, node);
	246	next = rb_next(&rbtree_node->node);
	247	rb_erase(&rbtree_node->node, &rbtree_ctx->root);
	248	kfree(rbtree_node->block);
	249	kfree(rbtree_node);
	250	}
	251
	252	/* release the resources */
	253	kfree(map->cache);
	254	map->cache = NULL;
	255
	256	return 0;
	257	}
	258
	259	static int regcache_rbtree_read(struct regmap *map,
	260	unsigned int reg, unsigned int *value)
	261	{
28644c80	262	struct regcache_rbtree_node *rbnode;
28644c80 DP	263	unsigned int reg_tmp;
28644c80 DP	264
3405addd	265	rbnode = regcache_rbtree_lookup(map, reg);
28644c80	266	if (rbnode) {
f01ee60f	267	reg_tmp = (reg - rbnode->base_reg) / map->reg_stride;
0c7ed856 DP	268	if (!regcache_reg_present(map, reg))
0c7ed856 DP	269	return -ENOENT;
879082c9	270	*value = regcache_rbtree_get_register(map, rbnode, reg_tmp);
28644c80	271	} else {
6e6ace00	272	return -ENOENT;
28644c80 DP	273	}
	274
	275	return 0;
	276	}
	277
	278
879082c9 MB	279	static int regcache_rbtree_insert_to_block(struct regmap *map,
879082c9 MB	280	struct regcache_rbtree_node *rbnode,
472fdec7 LPC	281	unsigned int base_reg,
	282	unsigned int top_reg,
	283	unsigned int reg,
879082c9	284	unsigned int value)
28644c80	285	{
472fdec7 LPC	286	unsigned int blklen;
472fdec7 LPC	287	unsigned int pos, offset;
28644c80 DP	288	u8 *blk;
28644c80 DP	289
472fdec7 LPC	290	blklen = (top_reg - base_reg) / map->reg_stride + 1;
	291	pos = (reg - base_reg) / map->reg_stride;
	292	offset = (rbnode->base_reg - base_reg) / map->reg_stride;
	293
28644c80	294	blk = krealloc(rbnode->block,
472fdec7	295	blklen * map->cache_word_size,
879082c9	296	GFP_KERNEL);
28644c80 DP	297	if (!blk)
	298	return -ENOMEM;
	299
	300	/* insert the register value in the correct place in the rbnode block */
472fdec7 LPC	301	if (pos == 0)
	302	memmove(blk + offset * map->cache_word_size,
	303	blk, rbnode->blklen * map->cache_word_size);
28644c80 DP	304
	305	/* update the rbnode block, its size and the base register */
	306	rbnode->block = blk;
472fdec7 LPC	307	rbnode->blklen = blklen;
472fdec7 LPC	308	rbnode->base_reg = base_reg;
28644c80	309
879082c9	310	regcache_rbtree_set_register(map, rbnode, pos, value);
28644c80 DP	311	return 0;
	312	}
	313
0186645d MB	314	static struct regcache_rbtree_node *
	315	regcache_rbtree_node_alloc(struct regmap *map, unsigned int reg)
	316	{
	317	struct regcache_rbtree_node *rbnode;
7278af5f MB	318	const struct regmap_range *range;
7278af5f MB	319	int i;
0186645d MB	320
	321	rbnode = kzalloc(sizeof(*rbnode), GFP_KERNEL);
	322	if (!rbnode)
	323	return NULL;
	324
7278af5f MB	325	/* If there is a read table then use it to guess at an allocation */
	326	if (map->rd_table) {
	327	for (i = 0; i < map->rd_table->n_yes_ranges; i++) {
	328	if (regmap_reg_in_range(reg,
	329	&map->rd_table->yes_ranges[i]))
	330	break;
	331	}
	332
	333	if (i != map->rd_table->n_yes_ranges) {
	334	range = &map->rd_table->yes_ranges[i];
b6752123 LPC	335	rbnode->blklen = (range->range_max - range->range_min) /
b6752123 LPC	336	map->reg_stride + 1;
7278af5f MB	337	rbnode->base_reg = range->range_min;
	338	}
	339	}
	340
	341	if (!rbnode->blklen) {
	342	rbnode->blklen = sizeof(*rbnode);
	343	rbnode->base_reg = reg;
	344	}
	345
0186645d MB	346	rbnode->block = kmalloc(rbnode->blklen * map->cache_word_size,
	347	GFP_KERNEL);
	348	if (!rbnode->block) {
	349	kfree(rbnode);
	350	return NULL;
	351	}
	352
	353	return rbnode;
	354	}
	355
28644c80 DP	356	static int regcache_rbtree_write(struct regmap *map, unsigned int reg,
	357	unsigned int value)
	358	{
	359	struct regcache_rbtree_ctx *rbtree_ctx;
	360	struct regcache_rbtree_node rbnode, rbnode_tmp;
	361	struct rb_node *node;
28644c80	362	unsigned int reg_tmp;
28644c80 DP	363	int ret;
	364
	365	rbtree_ctx = map->cache;
0c7ed856	366	/* update the reg_present bitmap, make space if necessary */
78493f2d	367	ret = regcache_set_reg_present(map, reg);
0c7ed856 DP	368	if (ret < 0)
0c7ed856 DP	369	return ret;
0c7ed856	370
28644c80 DP	371	/* if we can't locate it in the cached rbnode we'll have
	372	* to traverse the rbtree looking for it.
	373	*/
3405addd	374	rbnode = regcache_rbtree_lookup(map, reg);
28644c80	375	if (rbnode) {
f01ee60f	376	reg_tmp = (reg - rbnode->base_reg) / map->reg_stride;
879082c9	377	regcache_rbtree_set_register(map, rbnode, reg_tmp, value);
28644c80	378	} else {
472fdec7 LPC	379	unsigned int base_reg, top_reg;
	380	unsigned int new_base_reg, new_top_reg;
	381	unsigned int min, max;
	382	unsigned int max_dist;
	383
	384	max_dist = map->reg_stride * sizeof(*rbnode_tmp) /
	385	map->cache_word_size;
	386	if (reg < max_dist)
	387	min = 0;
	388	else
	389	min = reg - max_dist;
	390	max = reg + max_dist;
	391
28644c80 DP	392	/* look for an adjacent register to the one we are about to add */
	393	for (node = rb_first(&rbtree_ctx->root); node;
	394	node = rb_next(node)) {
f01ee60f SW	395	rbnode_tmp = rb_entry(node, struct regcache_rbtree_node,
f01ee60f SW	396	node);
194c753a LPC	397
	398	regcache_rbtree_get_base_top_reg(map, rbnode_tmp,
	399	&base_reg, &top_reg);
	400
472fdec7 LPC	401	if (base_reg <= max && top_reg >= min) {
	402	new_base_reg = min(reg, base_reg);
	403	new_top_reg = max(reg, top_reg);
	404	} else {
194c753a	405	continue;
472fdec7	406	}
194c753a LPC	407
194c753a LPC	408	ret = regcache_rbtree_insert_to_block(map, rbnode_tmp,
472fdec7 LPC	409	new_base_reg,
	410	new_top_reg, reg,
	411	value);
194c753a LPC	412	if (ret)
	413	return ret;
	414	rbtree_ctx->cached_rbnode = rbnode_tmp;
	415	return 0;
28644c80	416	}
0186645d MB	417
	418	/* We did not manage to find a place to insert it in
	419	* an existing block so create a new rbnode.
28644c80	420	*/
0186645d	421	rbnode = regcache_rbtree_node_alloc(map, reg);
28644c80 DP	422	if (!rbnode)
28644c80 DP	423	return -ENOMEM;
0186645d MB	424	regcache_rbtree_set_register(map, rbnode,
0186645d MB	425	reg - rbnode->base_reg, value);
f01ee60f	426	regcache_rbtree_insert(map, &rbtree_ctx->root, rbnode);
28644c80 DP	427	rbtree_ctx->cached_rbnode = rbnode;
	428	}
	429
	430	return 0;
	431	}
	432
ac8d91c8 MB	433	static int regcache_rbtree_sync(struct regmap *map, unsigned int min,
ac8d91c8 MB	434	unsigned int max)
28644c80 DP	435	{
	436	struct regcache_rbtree_ctx *rbtree_ctx;
	437	struct rb_node *node;
	438	struct regcache_rbtree_node *rbnode;
b6752123 LPC	439	unsigned int base_reg, top_reg;
b6752123 LPC	440	unsigned int start, end;
28644c80	441	int ret;
28644c80 DP	442
	443	rbtree_ctx = map->cache;
	444	for (node = rb_first(&rbtree_ctx->root); node; node = rb_next(node)) {
	445	rbnode = rb_entry(node, struct regcache_rbtree_node, node);
ac8d91c8	446
b6752123 LPC	447	regcache_rbtree_get_base_top_reg(map, rbnode, &base_reg,
	448	&top_reg);
	449	if (base_reg > max)
ac8d91c8	450	break;
b6752123	451	if (top_reg < min)
ac8d91c8 MB	452	continue;
ac8d91c8 MB	453
b6752123 LPC	454	if (min > base_reg)
b6752123 LPC	455	start = (min - base_reg) / map->reg_stride;
ac8d91c8	456	else
b6752123	457	start = 0;
ac8d91c8	458
b6752123 LPC	459	if (max < top_reg)
b6752123 LPC	460	end = (max - base_reg) / map->reg_stride + 1;
ac8d91c8 MB	461	else
	462	end = rbnode->blklen;
	463
f8bd822c	464	ret = regcache_sync_block(map, rbnode->block, rbnode->base_reg,
b6752123	465	start, end);
f8bd822c MB	466	if (ret != 0)
f8bd822c MB	467	return ret;
28644c80 DP	468	}
28644c80 DP	469
f8bd822c	470	return regmap_async_complete(map);
28644c80 DP	471	}
	472
	473	struct regcache_ops regcache_rbtree_ops = {
	474	.type = REGCACHE_RBTREE,
	475	.name = "rbtree",
	476	.init = regcache_rbtree_init,
	477	.exit = regcache_rbtree_exit,
	478	.read = regcache_rbtree_read,
	479	.write = regcache_rbtree_write,
	480	.sync = regcache_rbtree_sync
	481	};