Adding upstream version 6.6.15.upstream/6.6.15

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

1 files changed, 398 insertions, 0 deletions

diff --git a/drivers/base/regmap/regcache-maple.c b/drivers/base/regmap/regcache-maple.c
new file mode 100644
index 0000000000..41edd6a430
--- /dev/null
+++ b/drivers/base/regmap/regcache-maple.c
@@ -0,0 +1,398 @@
+// SPDX-License-Identifier: GPL-2.0
+//
+// Register cache access API - maple tree based cache
+//
+// Copyright 2023 Arm, Ltd
+//
+// Author: Mark Brown <broonie@kernel.org>
+
+#include <linux/debugfs.h>
+#include <linux/device.h>
+#include <linux/maple_tree.h>
+#include <linux/slab.h>
+
+#include "internal.h"
+
+static int regcache_maple_read(struct regmap *map,
+			       unsigned int reg, unsigned int *value)
+{
+	struct maple_tree *mt = map->cache;
+	MA_STATE(mas, mt, reg, reg);
+	unsigned long *entry;
+
+	rcu_read_lock();
+
+	entry = mas_walk(&mas);
+	if (!entry) {
+		rcu_read_unlock();
+		return -ENOENT;
+	}
+
+	*value = entry[reg - mas.index];
+
+	rcu_read_unlock();
+
+	return 0;
+}
+
+static int regcache_maple_write(struct regmap *map, unsigned int reg,
+				unsigned int val)
+{
+	struct maple_tree *mt = map->cache;
+	MA_STATE(mas, mt, reg, reg);
+	unsigned long *entry, *upper, *lower;
+	unsigned long index, last;
+	size_t lower_sz, upper_sz;
+	int ret;
+
+	rcu_read_lock();
+
+	entry = mas_walk(&mas);
+	if (entry) {
+		entry[reg - mas.index] = val;
+		rcu_read_unlock();
+		return 0;
+	}
+
+	/* Any adjacent entries to extend/merge? */
+	mas_set_range(&mas, reg - 1, reg + 1);
+	index = reg;
+	last = reg;
+
+	lower = mas_find(&mas, reg - 1);
+	if (lower) {
+		index = mas.index;
+		lower_sz = (mas.last - mas.index + 1) * sizeof(unsigned long);
+	}
+
+	upper = mas_find(&mas, reg + 1);
+	if (upper) {
+		last = mas.last;
+		upper_sz = (mas.last - mas.index + 1) * sizeof(unsigned long);
+	}
+
+	rcu_read_unlock();
+
+	entry = kmalloc((last - index + 1) * sizeof(unsigned long),
+			map->alloc_flags);
+	if (!entry)
+		return -ENOMEM;
+
+	if (lower)
+		memcpy(entry, lower, lower_sz);
+	entry[reg - index] = val;
+	if (upper)
+		memcpy(&entry[reg - index + 1], upper, upper_sz);
+
+	/*
+	 * This is safe because the regmap lock means the Maple lock
+	 * is redundant, but we need to take it due to lockdep asserts
+	 * in the maple tree code.
+	 */
+	mas_lock(&mas);
+
+	mas_set_range(&mas, index, last);
+	ret = mas_store_gfp(&mas, entry, map->alloc_flags);
+
+	mas_unlock(&mas);
+
+	if (ret == 0) {
+		kfree(lower);
+		kfree(upper);
+	}
+	
+	return ret;
+}
+
+static int regcache_maple_drop(struct regmap *map, unsigned int min,
+			       unsigned int max)
+{
+	struct maple_tree *mt = map->cache;
+	MA_STATE(mas, mt, min, max);
+	unsigned long *entry, *lower, *upper;
+	unsigned long lower_index, lower_last;
+	unsigned long upper_index, upper_last;
+	int ret;
+
+	lower = NULL;
+	upper = NULL;
+
+	mas_lock(&mas);
+
+	mas_for_each(&mas, entry, max) {
+		/*
+		 * This is safe because the regmap lock means the
+		 * Maple lock is redundant, but we need to take it due
+		 * to lockdep asserts in the maple tree code.
+		 */
+		mas_unlock(&mas);
+
+		/* Do we need to save any of this entry? */
+		if (mas.index < min) {
+			lower_index = mas.index;
+			lower_last = min -1;
+
+			lower = kmemdup(entry, ((min - mas.index) *
+						sizeof(unsigned long)),
+					map->alloc_flags);
+			if (!lower) {
+				ret = -ENOMEM;
+				goto out_unlocked;
+			}
+		}
+
+		if (mas.last > max) {
+			upper_index = max + 1;
+			upper_last = mas.last;
+
+			upper = kmemdup(&entry[max + 1],
+					((mas.last - max) *
+					 sizeof(unsigned long)),
+					map->alloc_flags);
+			if (!upper) {
+				ret = -ENOMEM;
+				goto out_unlocked;
+			}
+		}
+
+		kfree(entry);
+		mas_lock(&mas);
+		mas_erase(&mas);
+
+		/* Insert new nodes with the saved data */
+		if (lower) {
+			mas_set_range(&mas, lower_index, lower_last);
+			ret = mas_store_gfp(&mas, lower, map->alloc_flags);
+			if (ret != 0)
+				goto out;
+			lower = NULL;
+		}
+
+		if (upper) {
+			mas_set_range(&mas, upper_index, upper_last);
+			ret = mas_store_gfp(&mas, upper, map->alloc_flags);
+			if (ret != 0)
+				goto out;
+			upper = NULL;
+		}
+	}
+
+out:
+	mas_unlock(&mas);
+out_unlocked:
+	kfree(lower);
+	kfree(upper);
+
+	return ret;
+}
+
+static int regcache_maple_sync_block(struct regmap *map, unsigned long *entry,
+				     struct ma_state *mas,
+				     unsigned int min, unsigned int max)
+{
+	void *buf;
+	unsigned long r;
+	size_t val_bytes = map->format.val_bytes;
+	int ret = 0;
+
+	mas_pause(mas);
+	rcu_read_unlock();
+
+	/*
+	 * Use a raw write if writing more than one register to a
+	 * device that supports raw writes to reduce transaction
+	 * overheads.
+	 */
+	if (max - min > 1 && regmap_can_raw_write(map)) {
+		buf = kmalloc(val_bytes * (max - min), map->alloc_flags);
+		if (!buf) {
+			ret = -ENOMEM;
+			goto out;
+		}
+
+		/* Render the data for a raw write */
+		for (r = min; r < max; r++) {
+			regcache_set_val(map, buf, r - min,
+					 entry[r - mas->index]);
+		}
+
+		ret = _regmap_raw_write(map, min, buf, (max - min) * val_bytes,
+					false);
+
+		kfree(buf);
+	} else {
+		for (r = min; r < max; r++) {
+			ret = _regmap_write(map, r,
+					    entry[r - mas->index]);
+			if (ret != 0)
+				goto out;
+		}
+	}
+
+out:
+	rcu_read_lock();
+
+	return ret;
+}
+
+static int regcache_maple_sync(struct regmap *map, unsigned int min,
+			       unsigned int max)
+{
+	struct maple_tree *mt = map->cache;
+	unsigned long *entry;
+	MA_STATE(mas, mt, min, max);
+	unsigned long lmin = min;
+	unsigned long lmax = max;
+	unsigned int r, v, sync_start;
+	int ret;
+	bool sync_needed = false;
+
+	map->cache_bypass = true;
+
+	rcu_read_lock();
+
+	mas_for_each(&mas, entry, max) {
+		for (r = max(mas.index, lmin); r <= min(mas.last, lmax); r++) {
+			v = entry[r - mas.index];
+
+			if (regcache_reg_needs_sync(map, r, v)) {
+				if (!sync_needed) {
+					sync_start = r;
+					sync_needed = true;
+				}
+				continue;
+			}
+
+			if (!sync_needed)
+				continue;
+
+			ret = regcache_maple_sync_block(map, entry, &mas,
+							sync_start, r);
+			if (ret != 0)
+				goto out;
+			sync_needed = false;
+		}
+
+		if (sync_needed) {
+			ret = regcache_maple_sync_block(map, entry, &mas,
+							sync_start, r);
+			if (ret != 0)
+				goto out;
+			sync_needed = false;
+		}
+	}
+
+out:
+	rcu_read_unlock();
+
+	map->cache_bypass = false;
+
+	return ret;
+}
+
+static int regcache_maple_exit(struct regmap *map)
+{
+	struct maple_tree *mt = map->cache;
+	MA_STATE(mas, mt, 0, UINT_MAX);
+	unsigned int *entry;;
+
+	/* if we've already been called then just return */
+	if (!mt)
+		return 0;
+
+	mas_lock(&mas);
+	mas_for_each(&mas, entry, UINT_MAX)
+		kfree(entry);
+	__mt_destroy(mt);
+	mas_unlock(&mas);
+
+	kfree(mt);
+	map->cache = NULL;
+
+	return 0;
+}
+
+static int regcache_maple_insert_block(struct regmap *map, int first,
+					int last)
+{
+	struct maple_tree *mt = map->cache;
+	MA_STATE(mas, mt, first, last);
+	unsigned long *entry;
+	int i, ret;
+
+	entry = kcalloc(last - first + 1, sizeof(unsigned long), map->alloc_flags);
+	if (!entry)
+		return -ENOMEM;
+
+	for (i = 0; i < last - first + 1; i++)
+		entry[i] = map->reg_defaults[first + i].def;
+
+	mas_lock(&mas);
+
+	mas_set_range(&mas, map->reg_defaults[first].reg,
+		      map->reg_defaults[last].reg);
+	ret = mas_store_gfp(&mas, entry, map->alloc_flags);
+
+	mas_unlock(&mas);
+
+	if (ret)
+		kfree(entry);
+
+	return ret;
+}
+
+static int regcache_maple_init(struct regmap *map)
+{
+	struct maple_tree *mt;
+	int i;
+	int ret;
+	int range_start;
+
+	mt = kmalloc(sizeof(*mt), GFP_KERNEL);
+	if (!mt)
+		return -ENOMEM;
+	map->cache = mt;
+
+	mt_init(mt);
+
+	if (!map->num_reg_defaults)
+		return 0;
+
+	range_start = 0;
+
+	/* Scan for ranges of contiguous registers */
+	for (i = 1; i < map->num_reg_defaults; i++) {
+		if (map->reg_defaults[i].reg !=
+		    map->reg_defaults[i - 1].reg + 1) {
+			ret = regcache_maple_insert_block(map, range_start,
+							  i - 1);
+			if (ret != 0)
+				goto err;
+
+			range_start = i;
+		}
+	}
+
+	/* Add the last block */
+	ret = regcache_maple_insert_block(map, range_start,
+					  map->num_reg_defaults - 1);
+	if (ret != 0)
+		goto err;
+
+	return 0;
+
+err:
+	regcache_maple_exit(map);
+	return ret;
+}
+
+struct regcache_ops regcache_maple_ops = {
+	.type = REGCACHE_MAPLE,
+	.name = "maple",
+	.init = regcache_maple_init,
+	.exit = regcache_maple_exit,
+	.read = regcache_maple_read,
+	.write = regcache_maple_write,
+	.drop = regcache_maple_drop,
+	.sync = regcache_maple_sync,
+};