summaryrefslogtreecommitdiff
path: root/arch/arm64/kernel/cacheinfo.c
diff options
context:
space:
mode:
Diffstat (limited to 'arch/arm64/kernel/cacheinfo.c')
-rw-r--r--arch/arm64/kernel/cacheinfo.c128
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 000000000..b8629d52f
--- /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)