Adding upstream version 4.19.249.upstream/4.19.249upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 567 insertions, 0 deletions

diff --git a/drivers/base/regmap/regcache-rbtree.c b/drivers/base/regmap/regcache-rbtree.c
new file mode 100644
index 000000000..e9b7ce8c2
--- /dev/null
+++ b/drivers/base/regmap/regcache-rbtree.c
@@ -0,0 +1,567 @@
+/*
+ * 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/debugfs.h>
+#include <linux/device.h>
+#include <linux/rbtree.h>
+#include <linux/seq_file.h>
+#include <linux/slab.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 {
+	/* block of adjacent registers */
+	void *block;
+	/* Which registers are present */
+	long *cache_present;
+	/* base register handled by this block */
+	unsigned int base_reg;
+	/* number of registers available in the block */
+	unsigned int blklen;
+	/* the actual rbtree node holding this block */
+	struct rb_node node;
+} __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)
+{
+	set_bit(idx, rbnode->cache_present);
+	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 = rb_entry(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 = rb_entry(*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);
+
+	for (node = rb_first(&rbtree_ctx->root); node != NULL;
+	     node = rb_next(node)) {
+		n = rb_entry(node, struct regcache_rbtree_node, node);
+		mem_size += sizeof(*n);
+		mem_size += (n->blklen * map->cache_word_size);
+		mem_size += BITS_TO_LONGS(n->blklen) * sizeof(long);
+
+		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);
+}
+#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;
+	}
+
+	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->cache_present);
+		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 (!test_bit(reg_tmp, rbnode->cache_present))
+			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;
+	unsigned long *present;
+	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;
+
+	rbnode->block = blk;
+
+	if (BITS_TO_LONGS(blklen) > BITS_TO_LONGS(rbnode->blklen)) {
+		present = krealloc(rbnode->cache_present,
+				   BITS_TO_LONGS(blklen) * sizeof(*present),
+				   GFP_KERNEL);
+		if (!present)
+			return -ENOMEM;
+
+		memset(present + BITS_TO_LONGS(rbnode->blklen), 0,
+		       (BITS_TO_LONGS(blklen) - BITS_TO_LONGS(rbnode->blklen))
+		       * sizeof(*present));
+	} else {
+		present = rbnode->cache_present;
+	}
+
+	/* 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);
+		bitmap_shift_left(present, present, offset, blklen);
+	}
+
+	/* update the rbnode block, its size and the base register */
+	rbnode->blklen = blklen;
+	rbnode->base_reg = base_reg;
+	rbnode->cache_present = present;
+
+	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 = 1;
+		rbnode->base_reg = reg;
+	}
+
+	rbnode->block = kmalloc_array(rbnode->blklen, map->cache_word_size,
+				      GFP_KERNEL);
+	if (!rbnode->block)
+		goto err_free;
+
+	rbnode->cache_present = kcalloc(BITS_TO_LONGS(rbnode->blklen),
+					sizeof(*rbnode->cache_present),
+					GFP_KERNEL);
+	if (!rbnode->cache_present)
+		goto err_free_block;
+
+	return rbnode;
+
+err_free_block:
+	kfree(rbnode->block);
+err_free:
+	kfree(rbnode);
+	return NULL;
+}
+
+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;
+
+	/* 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;
+		unsigned int dist, best_dist = UINT_MAX;
+
+		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 */
+		node = rbtree_ctx->root.rb_node;
+		while (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) {
+				if (reg < base_reg)
+					dist = base_reg - reg;
+				else if (reg > top_reg)
+					dist = reg - top_reg;
+				else
+					dist = 0;
+				if (dist < best_dist) {
+					rbnode = rbnode_tmp;
+					best_dist = dist;
+					new_base_reg = min(reg, base_reg);
+					new_top_reg = max(reg, top_reg);
+				}
+			}
+
+			/*
+			 * Keep looking, we want to choose the closest block,
+			 * otherwise we might end up creating overlapping
+			 * blocks, which breaks the rbtree.
+			 */
+			if (reg < base_reg)
+				node = node->rb_left;
+			else if (reg > top_reg)
+				node = node->rb_right;
+			else
+				break;
+		}
+
+		if (rbnode) {
+			ret = regcache_rbtree_insert_to_block(map, rbnode,
+							      new_base_reg,
+							      new_top_reg, reg,
+							      value);
+			if (ret)
+				return ret;
+			rbtree_ctx->cached_rbnode = rbnode;
+			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->cache_present,
+					  rbnode->base_reg, start, end);
+		if (ret != 0)
+			return ret;
+	}
+
+	return regmap_async_complete(map);
+}
+
+static int regcache_rbtree_drop(struct regmap *map, unsigned int min,
+				unsigned int max)
+{
+	struct regcache_rbtree_ctx *rbtree_ctx;
+	struct regcache_rbtree_node *rbnode;
+	struct rb_node *node;
+	unsigned int base_reg, top_reg;
+	unsigned int start, end;
+
+	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;
+
+		bitmap_clear(rbnode->cache_present, start, end - start);
+	}
+
+	return 0;
+}
+
+struct regcache_ops regcache_rbtree_ops = {
+	.type = REGCACHE_RBTREE,
+	.name = "rbtree",
+	.init = regcache_rbtree_init,
+	.exit = regcache_rbtree_exit,
+#ifdef CONFIG_DEBUG_FS
+	.debugfs_init = rbtree_debugfs_init,
+#endif
+	.read = regcache_rbtree_read,
+	.write = regcache_rbtree_write,
+	.sync = regcache_rbtree_sync,
+	.drop = regcache_rbtree_drop,
+};