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https://github.com/AuxXxilium/linux_dsm_epyc7002.git
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ce11020f0e
Here we introduce regcache_flat_get_index(), which using register stride order and bit rotation, will save some memory spaces for flat cache. Though this will also lost some access performance, since the bit rotation is used to get the index of the cache array, and this could be ingored for memory I/O accessing. Signed-off-by: Xiubo Li <lixiubo@cmss.chinamobile.com> Signed-off-by: Mark Brown <broonie@kernel.org>
83 lines
1.8 KiB
C
83 lines
1.8 KiB
C
/*
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* Register cache access API - flat caching support
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*
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* Copyright 2012 Wolfson Microelectronics plc
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*
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* Author: Mark Brown <broonie@opensource.wolfsonmicro.com>
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*/
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#include <linux/device.h>
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#include <linux/seq_file.h>
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#include <linux/slab.h>
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#include "internal.h"
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static inline unsigned int regcache_flat_get_index(const struct regmap *map,
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unsigned int reg)
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{
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return regcache_get_index_by_order(map, reg);
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}
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static int regcache_flat_init(struct regmap *map)
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{
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int i;
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unsigned int *cache;
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if (!map || map->reg_stride_order < 0)
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return -EINVAL;
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map->cache = kcalloc(regcache_flat_get_index(map, map->max_register)
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+ 1, sizeof(unsigned int), GFP_KERNEL);
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if (!map->cache)
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return -ENOMEM;
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cache = map->cache;
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for (i = 0; i < map->num_reg_defaults; i++)
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cache[regcache_flat_get_index(map, map->reg_defaults[i].reg)] =
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map->reg_defaults[i].def;
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return 0;
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}
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static int regcache_flat_exit(struct regmap *map)
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{
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kfree(map->cache);
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map->cache = NULL;
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return 0;
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}
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static int regcache_flat_read(struct regmap *map,
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unsigned int reg, unsigned int *value)
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{
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unsigned int *cache = map->cache;
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*value = cache[regcache_flat_get_index(map, reg)];
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return 0;
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}
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static int regcache_flat_write(struct regmap *map, unsigned int reg,
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unsigned int value)
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{
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unsigned int *cache = map->cache;
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cache[regcache_flat_get_index(map, reg)] = value;
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return 0;
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}
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struct regcache_ops regcache_flat_ops = {
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.type = REGCACHE_FLAT,
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.name = "flat",
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.init = regcache_flat_init,
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.exit = regcache_flat_exit,
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.read = regcache_flat_read,
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.write = regcache_flat_write,
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};
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