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/cacheinfo.h>
  21 #include <linux/of.h>
  22
  23 #define MAX_CACHE_LEVEL                 7       /* Max 7 level supported */
  24 /* Ctypen, bits[3(n - 1) + 2 : 3(n - 1)], for n = 1 to 7 */
  25 #define CLIDR_CTYPE_SHIFT(level)        (3 * (level - 1))
  26 #define CLIDR_CTYPE_MASK(level)         (7 << CLIDR_CTYPE_SHIFT(level))
  27 #define CLIDR_CTYPE(clidr, level)       \
  28         (((clidr) & CLIDR_CTYPE_MASK(level)) >> CLIDR_CTYPE_SHIFT(level))
  29
  30 static inline enum cache_type get_cache_type(int level)
  31 {
  32         u64 clidr;
  33
  34         if (level > MAX_CACHE_LEVEL)
  35                 return CACHE_TYPE_NOCACHE;
  36         clidr = read_sysreg(clidr_el1);
  37         return CLIDR_CTYPE(clidr, level);
  38 }
  39
  40 static void ci_leaf_init(struct cacheinfo *this_leaf,
  41                          enum cache_type type, unsigned int level)
  42 {
  43         this_leaf->level = level;
  44         this_leaf->type = type;
  45 }
  46
  47 static int __init_cache_level(unsigned int cpu)
  48 {
  49         unsigned int ctype, level, leaves, of_level;
  50         struct cpu_cacheinfo *this_cpu_ci = get_cpu_cacheinfo(cpu);
  51
  52         for (level = 1, leaves = 0; level <= MAX_CACHE_LEVEL; level++) {
  53                 ctype = get_cache_type(level);
  54                 if (ctype == CACHE_TYPE_NOCACHE) {
  55                         level--;
  56                         break;
  57                 }
  58                 /* Separate instruction and data caches */
  59                 leaves += (ctype == CACHE_TYPE_SEPARATE) ? 2 : 1;
  60         }
  61
  62         of_level = of_find_last_cache_level(cpu);
  63         if (level < of_level) {
  64                 /*
  65                  * some external caches not specified in CLIDR_EL1
  66                  * the information may be available in the device tree
  67                  * only unified external caches are considered here
  68                  */
  69                 leaves += (of_level - level);
  70                 level = of_level;
  71         }
  72
  73         this_cpu_ci->num_levels = level;
  74         this_cpu_ci->num_leaves = leaves;
  75         return 0;
  76 }
  77
  78 static int __populate_cache_leaves(unsigned int cpu)
  79 {
  80         unsigned int level, idx;
  81         enum cache_type type;
  82         struct cpu_cacheinfo *this_cpu_ci = get_cpu_cacheinfo(cpu);
  83         struct cacheinfo *this_leaf = this_cpu_ci->info_list;
  84
  85         for (idx = 0, level = 1; level <= this_cpu_ci->num_levels &&
  86              idx < this_cpu_ci->num_leaves; idx++, level++) {
  87                 type = get_cache_type(level);
  88                 if (type == CACHE_TYPE_SEPARATE) {
  89                         ci_leaf_init(this_leaf++, CACHE_TYPE_DATA, level);
  90                         ci_leaf_init(this_leaf++, CACHE_TYPE_INST, level);
  91                 } else {
  92                         ci_leaf_init(this_leaf++, type, level);
  93                 }
  94         }
  95         return 0;
  96 }
  97
  98 DEFINE_SMP_CALL_CACHE_FUNCTION(init_cache_level)
  99 DEFINE_SMP_CALL_CACHE_FUNCTION(populate_cache_leaves)