diff options
Diffstat (limited to 'arch/arm/kernel/cacheinfo.c')
| -rw-r--r-- | arch/arm/kernel/cacheinfo.c | 173 |
1 files changed, 173 insertions, 0 deletions
diff --git a/arch/arm/kernel/cacheinfo.c b/arch/arm/kernel/cacheinfo.c new file mode 100644 index 000000000000..e1469b641780 --- /dev/null +++ b/arch/arm/kernel/cacheinfo.c @@ -0,0 +1,173 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * ARM cacheinfo support + * + * Copyright (C) 2023 Linaro Ltd. + * Copyright (C) 2015 ARM Ltd. + * All Rights Reserved + */ + +#include <linux/bitfield.h> +#include <linux/cacheinfo.h> +#include <linux/of.h> + +#include <asm/cachetype.h> +#include <asm/cputype.h> +#include <asm/system_info.h> + +/* 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)) + +#define MAX_CACHE_LEVEL 7 /* Max 7 level supported */ + +#define CTR_FORMAT_MASK GENMASK(31, 29) +#define CTR_FORMAT_ARMV6 0 +#define CTR_FORMAT_ARMV7 4 +#define CTR_CWG_MASK GENMASK(27, 24) +#define CTR_DSIZE_LEN_MASK GENMASK(13, 12) +#define CTR_ISIZE_LEN_MASK GENMASK(1, 0) + +/* Also valid for v7m */ +static inline int cache_line_size_cp15(void) +{ + u32 ctr = read_cpuid_cachetype(); + u32 format = FIELD_GET(CTR_FORMAT_MASK, ctr); + + if (format == CTR_FORMAT_ARMV7) { + u32 cwg = FIELD_GET(CTR_CWG_MASK, ctr); + + return cwg ? 4 << cwg : ARCH_DMA_MINALIGN; + } else if (WARN_ON_ONCE(format != CTR_FORMAT_ARMV6)) { + return ARCH_DMA_MINALIGN; + } + + return 8 << max(FIELD_GET(CTR_ISIZE_LEN_MASK, ctr), + FIELD_GET(CTR_DSIZE_LEN_MASK, ctr)); +} + +int cache_line_size(void) +{ + if (coherency_max_size != 0) + return coherency_max_size; + + /* CP15 is optional / implementation defined before ARMv6 */ + if (cpu_architecture() < CPU_ARCH_ARMv6) + return ARCH_DMA_MINALIGN; + + return cache_line_size_cp15(); +} +EXPORT_SYMBOL_GPL(cache_line_size); + +static inline enum cache_type get_cache_type(int level) +{ + u32 clidr; + + if (level > MAX_CACHE_LEVEL) + return CACHE_TYPE_NOCACHE; + + clidr = read_clidr(); + + return CLIDR_CTYPE(clidr, level); +} + +static void ci_leaf_init(struct cacheinfo *this_leaf, + enum cache_type type, unsigned int level) +{ + this_leaf->level = level; + this_leaf->type = type; +} + +static int detect_cache_level(unsigned int *level_p, unsigned int *leaves_p) +{ + unsigned int ctype, level, leaves; + u32 ctr, format; + + /* CLIDR is not present before ARMv7/v7m */ + if (cpu_architecture() < CPU_ARCH_ARMv7) + return -EOPNOTSUPP; + + /* Don't try reading CLIDR if CTR declares old format */ + ctr = read_cpuid_cachetype(); + format = FIELD_GET(CTR_FORMAT_MASK, ctr); + if (format != CTR_FORMAT_ARMV7) + return -EOPNOTSUPP; + + 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; + } + + *level_p = level; + *leaves_p = leaves; + + return 0; +} + +int early_cache_level(unsigned int cpu) +{ + struct cpu_cacheinfo *this_cpu_ci = get_cpu_cacheinfo(cpu); + + return detect_cache_level(&this_cpu_ci->num_levels, &this_cpu_ci->num_leaves); +} + +int init_cache_level(unsigned int cpu) +{ + unsigned int level, leaves; + struct cpu_cacheinfo *this_cpu_ci = get_cpu_cacheinfo(cpu); + int fw_level; + int ret; + + ret = detect_cache_level(&level, &leaves); + if (ret) + return ret; + + fw_level = of_find_last_cache_level(cpu); + + if (level < fw_level) { + /* + * some external caches not specified in CLIDR_EL1 + * the information may be available in the device tree + * only unified external caches are considered here + */ + leaves += (fw_level - level); + level = fw_level; + } + + this_cpu_ci->num_levels = level; + this_cpu_ci->num_leaves = leaves; + return 0; +} + +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; + unsigned int arch = cpu_architecture(); + + /* CLIDR is not present before ARMv7/v7m */ + if (arch < CPU_ARCH_ARMv7) + return -EOPNOTSUPP; + + 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; +} |