cacheinfo.c

  1// SPDX-License-Identifier: GPL-2.0-only
  2/*
  3 * Copyright (C) 2017 SiFive
  4 */
  5
  6#include <linux/acpi.h>
  7#include <linux/cpu.h>
  8#include <linux/of.h>
  9#include <asm/cacheinfo.h>
 10
 11static struct riscv_cacheinfo_ops *rv_cache_ops;
 12
 13void riscv_set_cacheinfo_ops(struct riscv_cacheinfo_ops *ops)
 14{
 15	rv_cache_ops = ops;
 16}
 17EXPORT_SYMBOL_GPL(riscv_set_cacheinfo_ops);
 18
 19const struct attribute_group *
 20cache_get_priv_group(struct cacheinfo *this_leaf)
 21{
 22	if (rv_cache_ops && rv_cache_ops->get_priv_group)
 23		return rv_cache_ops->get_priv_group(this_leaf);
 24	return NULL;
 25}
 26
 27static struct cacheinfo *get_cacheinfo(u32 level, enum cache_type type)
 28{
 29	/*
 30	 * Using raw_smp_processor_id() elides a preemptability check, but this
 31	 * is really indicative of a larger problem: the cacheinfo UABI assumes
 32	 * that cores have a homonogenous view of the cache hierarchy.  That
 33	 * happens to be the case for the current set of RISC-V systems, but
 34	 * likely won't be true in general.  Since there's no way to provide
 35	 * correct information for these systems via the current UABI we're
 36	 * just eliding the check for now.
 37	 */
 38	struct cpu_cacheinfo *this_cpu_ci = get_cpu_cacheinfo(raw_smp_processor_id());
 39	struct cacheinfo *this_leaf;
 40	int index;
 41
 42	for (index = 0; index < this_cpu_ci->num_leaves; index++) {
 43		this_leaf = this_cpu_ci->info_list + index;
 44		if (this_leaf->level == level && this_leaf->type == type)
 45			return this_leaf;
 46	}
 47
 48	return NULL;
 49}
 50
 51uintptr_t get_cache_size(u32 level, enum cache_type type)
 52{
 53	struct cacheinfo *this_leaf = get_cacheinfo(level, type);
 54
 55	return this_leaf ? this_leaf->size : 0;
 56}
 57
 58uintptr_t get_cache_geometry(u32 level, enum cache_type type)
 59{
 60	struct cacheinfo *this_leaf = get_cacheinfo(level, type);
 61
 62	return this_leaf ? (this_leaf->ways_of_associativity << 16 |
 63			    this_leaf->coherency_line_size) :
 64			   0;
 65}
 66
 67static void ci_leaf_init(struct cacheinfo *this_leaf,
 68			 enum cache_type type, unsigned int level)
 69{
 70	this_leaf->level = level;
 71	this_leaf->type = type;
 72}
 73
 74int init_cache_level(unsigned int cpu)
 75{
 76	return init_of_cache_level(cpu);
 77}
 78
 79int populate_cache_leaves(unsigned int cpu)
 80{
 81	struct cpu_cacheinfo *this_cpu_ci = get_cpu_cacheinfo(cpu);
 82	struct cacheinfo *this_leaf = this_cpu_ci->info_list;
 83	struct device_node *np, *prev;
 84	int levels = 1, level = 1;
 85
 86	if (!acpi_disabled) {
 87		int ret, fw_levels, split_levels;
 88
 89		ret = acpi_get_cache_info(cpu, &fw_levels, &split_levels);
 90		if (ret)
 91			return ret;
 92
 93		BUG_ON((split_levels > fw_levels) ||
 94		       (split_levels + fw_levels > this_cpu_ci->num_leaves));
 95
 96		for (; level <= this_cpu_ci->num_levels; level++) {
 97			if (level <= split_levels) {
 98				ci_leaf_init(this_leaf++, CACHE_TYPE_DATA, level);
 99				ci_leaf_init(this_leaf++, CACHE_TYPE_INST, level);
100			} else {
101				ci_leaf_init(this_leaf++, CACHE_TYPE_UNIFIED, level);
102			}
103		}
104		return 0;
105	}
106
107	np = of_cpu_device_node_get(cpu);
108	if (!np)
109		return -ENOENT;
110
111	if (of_property_present(np, "cache-size"))
112		ci_leaf_init(this_leaf++, CACHE_TYPE_UNIFIED, level);
113	if (of_property_present(np, "i-cache-size"))
114		ci_leaf_init(this_leaf++, CACHE_TYPE_INST, level);
115	if (of_property_present(np, "d-cache-size"))
116		ci_leaf_init(this_leaf++, CACHE_TYPE_DATA, level);
117
118	prev = np;
119	while ((np = of_find_next_cache_node(np))) {
120		of_node_put(prev);
121		prev = np;
122		if (!of_device_is_compatible(np, "cache"))
123			break;
124		if (of_property_read_u32(np, "cache-level", &level))
125			break;
126		if (level <= levels)
127			break;
128		if (of_property_present(np, "cache-size"))
129			ci_leaf_init(this_leaf++, CACHE_TYPE_UNIFIED, level);
130		if (of_property_present(np, "i-cache-size"))
131			ci_leaf_init(this_leaf++, CACHE_TYPE_INST, level);
132		if (of_property_present(np, "d-cache-size"))
133			ci_leaf_init(this_leaf++, CACHE_TYPE_DATA, level);
134		levels = level;
135	}
136	of_node_put(np);
137
138	return 0;
139}