diff options
Diffstat (limited to 'arch/arm64/kernel/cacheinfo.c')
| -rw-r--r-- | arch/arm64/kernel/cacheinfo.c | 128 |
1 files changed, 128 insertions, 0 deletions
diff --git a/arch/arm64/kernel/cacheinfo.c b/arch/arm64/kernel/cacheinfo.c new file mode 100644 index 00000000000..b8629d52fba --- /dev/null +++ b/arch/arm64/kernel/cacheinfo.c @@ -0,0 +1,128 @@ +/* + * ARM64 cacheinfo support + * + * Copyright (C) 2015 ARM Ltd. + * All Rights Reserved + * + * 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. + * + * This program is distributed "as is" WITHOUT ANY WARRANTY of any + * kind, whether express or implied; without even the implied warranty + * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program. If not, see <http://www.gnu.org/licenses/>. + */ + +#include <linux/bitops.h> +#include <linux/cacheinfo.h> +#include <linux/cpu.h> +#include <linux/compiler.h> +#include <linux/of.h> + +#include <asm/cachetype.h> +#include <asm/processor.h> + +#define MAX_CACHE_LEVEL 7 /* Max 7 level supported */ +/* Ctypen, bits[3(n - 1) + 2 : 3(n - 1)], for n = 1 to 7 */ +#define CLIDR_CTYPE_SHIFT(level) (3 * (level - 1)) +#define CLIDR_CTYPE_MASK(level) (7 << CLIDR_CTYPE_SHIFT(level)) +#define CLIDR_CTYPE(clidr, level) \ + (((clidr) & CLIDR_CTYPE_MASK(level)) >> CLIDR_CTYPE_SHIFT(level)) + +static inline enum cache_type get_cache_type(int level) +{ + u64 clidr; + + if (level > MAX_CACHE_LEVEL) + return CACHE_TYPE_NOCACHE; + asm volatile ("mrs %x0, clidr_el1" : "=r" (clidr)); + return CLIDR_CTYPE(clidr, level); +} + +/* + * Cache Size Selection Register(CSSELR) selects which Cache Size ID + * Register(CCSIDR) is accessible by specifying the required cache + * level and the cache type. We need to ensure that no one else changes + * CSSELR by calling this in non-preemtible context + */ +u64 __attribute_const__ cache_get_ccsidr(u64 csselr) +{ + u64 ccsidr; + + WARN_ON(preemptible()); + + /* Put value into CSSELR */ + asm volatile("msr csselr_el1, %x0" : : "r" (csselr)); + isb(); + /* Read result out of CCSIDR */ + asm volatile("mrs %x0, ccsidr_el1" : "=r" (ccsidr)); + + return ccsidr; +} + +static void ci_leaf_init(struct cacheinfo *this_leaf, + enum cache_type type, unsigned int level) +{ + bool is_icache = type & CACHE_TYPE_INST; + u64 tmp = cache_get_ccsidr((level - 1) << 1 | is_icache); + + this_leaf->level = level; + this_leaf->type = type; + this_leaf->coherency_line_size = CACHE_LINESIZE(tmp); + this_leaf->number_of_sets = CACHE_NUMSETS(tmp); + this_leaf->ways_of_associativity = CACHE_ASSOCIATIVITY(tmp); + this_leaf->size = this_leaf->number_of_sets * + this_leaf->coherency_line_size * this_leaf->ways_of_associativity; + this_leaf->attributes = + ((tmp & CCSIDR_EL1_WRITE_THROUGH) ? CACHE_WRITE_THROUGH : 0) | + ((tmp & CCSIDR_EL1_WRITE_BACK) ? CACHE_WRITE_BACK : 0) | + ((tmp & CCSIDR_EL1_READ_ALLOCATE) ? CACHE_READ_ALLOCATE : 0) | + ((tmp & CCSIDR_EL1_WRITE_ALLOCATE) ? CACHE_WRITE_ALLOCATE : 0); +} + +static int __init_cache_level(unsigned int cpu) +{ + unsigned int ctype, level, leaves; + struct cpu_cacheinfo *this_cpu_ci = get_cpu_cacheinfo(cpu); + + for (level = 1, leaves = 0; level <= MAX_CACHE_LEVEL; level++) { + ctype = get_cache_type(level); + if (ctype == CACHE_TYPE_NOCACHE) { + level--; + break; + } + /* Separate instruction and data caches */ + leaves += (ctype == CACHE_TYPE_SEPARATE) ? 2 : 1; + } + + this_cpu_ci->num_levels = level; + this_cpu_ci->num_leaves = leaves; + return 0; +} + +static int __populate_cache_leaves(unsigned int cpu) +{ + unsigned int level, idx; + enum cache_type type; + struct cpu_cacheinfo *this_cpu_ci = get_cpu_cacheinfo(cpu); + struct cacheinfo *this_leaf = this_cpu_ci->info_list; + + for (idx = 0, level = 1; level <= this_cpu_ci->num_levels && + idx < this_cpu_ci->num_leaves; idx++, level++) { + type = get_cache_type(level); + if (type == CACHE_TYPE_SEPARATE) { + ci_leaf_init(this_leaf++, CACHE_TYPE_DATA, level); + ci_leaf_init(this_leaf++, CACHE_TYPE_INST, level); + } else { + ci_leaf_init(this_leaf++, type, level); + } + } + return 0; +} + +DEFINE_SMP_CALL_CACHE_FUNCTION(init_cache_level) +DEFINE_SMP_CALL_CACHE_FUNCTION(populate_cache_leaves) |