This is a note to let you know that I've just added the patch titled
riscv: Add cache information in AUX vector
to the 5.4-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
riscv-add-cache-information-in-aux-vector.patch
and it can be found in the queue-5.4 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 2765d9652afac0a32f530d242038dfcb971dbb99
Author: Zong Li <zong.li@xxxxxxxxxx>
Date: Mon Aug 31 15:33:50 2020 +0800
riscv: Add cache information in AUX vector
[ Upstream commit 38f5bd23deae24c8fa67a2c574b6d43df27a8aa8 ]
There are no standard CSR registers to provide cache information, the
way for RISC-V is to get this information from DT. Currently, AT_L1I_X,
AT_L1D_X and AT_L2_X are present in glibc header, and sysconf syscall
could use them to get information of cache through AUX vector.
The result of 'getconf -a' as follows:
LEVEL1_ICACHE_SIZE 32768
LEVEL1_ICACHE_ASSOC 8
LEVEL1_ICACHE_LINESIZE 64
LEVEL1_DCACHE_SIZE 32768
LEVEL1_DCACHE_ASSOC 8
LEVEL1_DCACHE_LINESIZE 64
LEVEL2_CACHE_SIZE 2097152
LEVEL2_CACHE_ASSOC 32
LEVEL2_CACHE_LINESIZE 64
Signed-off-by: Zong Li <zong.li@xxxxxxxxxx>
Reviewed-by: Palmer Dabbelt <palmerdabbelt@xxxxxxxxxx>
Reviewed-by: Pekka Enberg <penberg@xxxxxxxxxx>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@xxxxxxxxxx>
Stable-dep-of: fb8179ce2996 ("riscv: cacheinfo: Use of_property_present() for non-boolean properties")
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/arch/riscv/include/asm/cacheinfo.h b/arch/riscv/include/asm/cacheinfo.h
index 5d9662e9aba85..d1a365215ec00 100644
--- a/arch/riscv/include/asm/cacheinfo.h
+++ b/arch/riscv/include/asm/cacheinfo.h
@@ -1,4 +1,7 @@
/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (C) 2020 SiFive
+ */
#ifndef _ASM_RISCV_CACHEINFO_H
#define _ASM_RISCV_CACHEINFO_H
@@ -11,5 +14,7 @@ struct riscv_cacheinfo_ops {
};
void riscv_set_cacheinfo_ops(struct riscv_cacheinfo_ops *ops);
+uintptr_t get_cache_size(u32 level, enum cache_type type);
+uintptr_t get_cache_geometry(u32 level, enum cache_type type);
#endif /* _ASM_RISCV_CACHEINFO_H */
diff --git a/arch/riscv/include/asm/elf.h b/arch/riscv/include/asm/elf.h
index ef04084bf0dee..4031cce8dd734 100644
--- a/arch/riscv/include/asm/elf.h
+++ b/arch/riscv/include/asm/elf.h
@@ -11,6 +11,7 @@
#include <uapi/asm/elf.h>
#include <asm/auxvec.h>
#include <asm/byteorder.h>
+#include <asm/cacheinfo.h>
/*
* These are used to set parameters in the core dumps.
@@ -60,6 +61,18 @@ extern unsigned long elf_hwcap;
do { \
NEW_AUX_ENT(AT_SYSINFO_EHDR, \
(elf_addr_t)current->mm->context.vdso); \
+ NEW_AUX_ENT(AT_L1I_CACHESIZE, \
+ get_cache_size(1, CACHE_TYPE_INST)); \
+ NEW_AUX_ENT(AT_L1I_CACHEGEOMETRY, \
+ get_cache_geometry(1, CACHE_TYPE_INST)); \
+ NEW_AUX_ENT(AT_L1D_CACHESIZE, \
+ get_cache_size(1, CACHE_TYPE_DATA)); \
+ NEW_AUX_ENT(AT_L1D_CACHEGEOMETRY, \
+ get_cache_geometry(1, CACHE_TYPE_DATA)); \
+ NEW_AUX_ENT(AT_L2_CACHESIZE, \
+ get_cache_size(2, CACHE_TYPE_UNIFIED)); \
+ NEW_AUX_ENT(AT_L2_CACHEGEOMETRY, \
+ get_cache_geometry(2, CACHE_TYPE_UNIFIED)); \
} while (0)
diff --git a/arch/riscv/include/uapi/asm/auxvec.h b/arch/riscv/include/uapi/asm/auxvec.h
index 22e0ae8884061..32c73ba1d5313 100644
--- a/arch/riscv/include/uapi/asm/auxvec.h
+++ b/arch/riscv/include/uapi/asm/auxvec.h
@@ -10,7 +10,28 @@
/* vDSO location */
#define AT_SYSINFO_EHDR 33
+/*
+ * The set of entries below represent more extensive information
+ * about the caches, in the form of two entry per cache type,
+ * one entry containing the cache size in bytes, and the other
+ * containing the cache line size in bytes in the bottom 16 bits
+ * and the cache associativity in the next 16 bits.
+ *
+ * The associativity is such that if N is the 16-bit value, the
+ * cache is N way set associative. A value if 0xffff means fully
+ * associative, a value of 1 means directly mapped.
+ *
+ * For all these fields, a value of 0 means that the information
+ * is not known.
+ */
+#define AT_L1I_CACHESIZE 40
+#define AT_L1I_CACHEGEOMETRY 41
+#define AT_L1D_CACHESIZE 42
+#define AT_L1D_CACHEGEOMETRY 43
+#define AT_L2_CACHESIZE 44
+#define AT_L2_CACHEGEOMETRY 45
+
/* entries in ARCH_DLINFO */
-#define AT_VECTOR_SIZE_ARCH 1
+#define AT_VECTOR_SIZE_ARCH 7
#endif /* _UAPI_ASM_RISCV_AUXVEC_H */
diff --git a/arch/riscv/kernel/cacheinfo.c b/arch/riscv/kernel/cacheinfo.c
index 8cd8224f47ee1..09892077ae087 100644
--- a/arch/riscv/kernel/cacheinfo.c
+++ b/arch/riscv/kernel/cacheinfo.c
@@ -3,7 +3,6 @@
* Copyright (C) 2017 SiFive
*/
-#include <linux/cacheinfo.h>
#include <linux/cpu.h>
#include <linux/of.h>
#include <linux/of_device.h>
@@ -25,6 +24,37 @@ cache_get_priv_group(struct cacheinfo *this_leaf)
return NULL;
}
+static struct cacheinfo *get_cacheinfo(u32 level, enum cache_type type)
+{
+ struct cpu_cacheinfo *this_cpu_ci = get_cpu_cacheinfo(smp_processor_id());
+ struct cacheinfo *this_leaf;
+ int index;
+
+ for (index = 0; index < this_cpu_ci->num_leaves; index++) {
+ this_leaf = this_cpu_ci->info_list + index;
+ if (this_leaf->level == level && this_leaf->type == type)
+ return this_leaf;
+ }
+
+ return NULL;
+}
+
+uintptr_t get_cache_size(u32 level, enum cache_type type)
+{
+ struct cacheinfo *this_leaf = get_cacheinfo(level, type);
+
+ return this_leaf ? this_leaf->size : 0;
+}
+
+uintptr_t get_cache_geometry(u32 level, enum cache_type type)
+{
+ struct cacheinfo *this_leaf = get_cacheinfo(level, type);
+
+ return this_leaf ? (this_leaf->ways_of_associativity << 16 |
+ this_leaf->coherency_line_size) :
+ 0;
+}
+
static void ci_leaf_init(struct cacheinfo *this_leaf, enum cache_type type,
unsigned int level, unsigned int size,
unsigned int sets, unsigned int line_size)
