--- /dev/null
+/*
+ * 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 = 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);
+
+ 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);
+ 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;
+
+ present = krealloc(rbnode->cache_present,
+ BITS_TO_LONGS(blklen) * sizeof(*present), GFP_KERNEL);
+ if (!present) {
+ kfree(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);
+ bitmap_shift_left(present, present, offset, blklen);
+ }
+
+ /* update the rbnode block, its size and the base register */
+ rbnode->block = blk;
+ 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(rbnode->blklen * map->cache_word_size,
+ GFP_KERNEL);
+ if (!rbnode->block)
+ goto err_free;
+
+ rbnode->cache_present = kzalloc(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;
+
+ 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->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,
+};
Code Review / kvmfornfv.git / blobdiff