arch/arm64/kernel/cacheinfo.c

   1 /*
   2  *  ARM64 cacheinfo support
   3  *
   4  *  Copyright (C) 2015 ARM Ltd.
   5  *  All Rights Reserved
   6  *
   7  * This program is free software; you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License version 2 as
   9  * published by the Free Software Foundation.
  10  *
  11  * This program is distributed "as is" WITHOUT ANY WARRANTY of any
  12  * kind, whether express or implied; without even the implied warranty
  13  * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  14  * GNU General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public License
  17  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  18  */
  19
  20 #include <linux/acpi.h>
  21 #include <linux/cacheinfo.h>
  22 #include <linux/of.h>
  23
  24 #define MAX_CACHE_LEVEL                 7       /* Max 7 level supported */
  25 /* Ctypen, bits[3(n - 1) + 2 : 3(n - 1)], for n = 1 to 7 */
  26 #define CLIDR_CTYPE_SHIFT(level)        (3 * (level - 1))
  27 #define CLIDR_CTYPE_MASK(level)         (7 << CLIDR_CTYPE_SHIFT(level))
  28 #define CLIDR_CTYPE(clidr, level)       \
  29         (((clidr) & CLIDR_CTYPE_MASK(level)) >> CLIDR_CTYPE_SHIFT(level))
  30
  31 static inline enum cache_type get_cache_type(int level)
  32 {
  33         u64 clidr;
  34
  35         if (level > MAX_CACHE_LEVEL)
  36                 return CACHE_TYPE_NOCACHE;
  37         clidr = read_sysreg(clidr_el1);
  38         return CLIDR_CTYPE(clidr, level);
  39 }
  40
  41 static void ci_leaf_init(struct cacheinfo *this_leaf,
  42                          enum cache_type type, unsigned int level)
  43 {
  44         this_leaf->level = level;
  45         this_leaf->type = type;
  46 }
  47
  48 static int __init_cache_level(unsigned int cpu)
  49 {
  50         unsigned int ctype, level, leaves, fw_level;
  51         struct cpu_cacheinfo *this_cpu_ci = get_cpu_cacheinfo(cpu);
  52
  53         for (level = 1, leaves = 0; level <= MAX_CACHE_LEVEL; level++) {
  54                 ctype = get_cache_type(level);
  55                 if (ctype == CACHE_TYPE_NOCACHE) {
  56                         level--;
  57                         break;
  58                 }
  59                 /* Separate instruction and data caches */
  60                 leaves += (ctype == CACHE_TYPE_SEPARATE) ? 2 : 1;
  61         }
  62
  63         if (acpi_disabled)
  64                 fw_level = of_find_last_cache_level(cpu);
  65         else
  66                 fw_level = acpi_find_last_cache_level(cpu);
  67
  68         if (level < fw_level) {
  69                 /*
  70                  * some external caches not specified in CLIDR_EL1
  71                  * the information may be available in the device tree
  72                  * only unified external caches are considered here
  73                  */
  74                 leaves += (fw_level - level);
  75                 level = fw_level;
  76         }
  77
  78         this_cpu_ci->num_levels = level;
  79         this_cpu_ci->num_leaves = leaves;
  80         return 0;
  81 }
  82
  83 static int __populate_cache_leaves(unsigned int cpu)
  84 {
  85         unsigned int level, idx;
  86         enum cache_type type;
  87         struct cpu_cacheinfo *this_cpu_ci = get_cpu_cacheinfo(cpu);
  88         struct cacheinfo *this_leaf = this_cpu_ci->info_list;
  89
  90         for (idx = 0, level = 1; level <= this_cpu_ci->num_levels &&
  91              idx < this_cpu_ci->num_leaves; idx++, level++) {
  92                 type = get_cache_type(level);
  93                 if (type == CACHE_TYPE_SEPARATE) {
  94                         ci_leaf_init(this_leaf++, CACHE_TYPE_DATA, level);
  95                         ci_leaf_init(this_leaf++, CACHE_TYPE_INST, level);
  96                 } else {
  97                         ci_leaf_init(this_leaf++, type, level);
  98                 }
  99         }
 100         return 0;
 101 }
 102
 103 DEFINE_SMP_CALL_CACHE_FUNCTION(init_cache_level)
 104 DEFINE_SMP_CALL_CACHE_FUNCTION(populate_cache_leaves)