[PATCH -fixes v2 3/4] riscv: Add ISA extension parsing for Sm and Ss
From: Samuel Holland
Date: Mon Feb 12 2024 - 22:38:27 EST
Previously, all extension version numbers were ignored. However, the
version number is important for these two extensions. The simplest way
to implement this is to use a separate bitmap bit for each supported
version, with each successive version implying all of the previous ones.
This allows alternatives and riscv_has_extension_[un]likely() to work
naturally.
To avoid duplicate extensions in /proc/cpuinfo, the new successor_id
field allows hiding all but the newest implemented version of an
extension.
Cc: <stable@xxxxxxxxxxxxxxx> # v6.7+
Signed-off-by: Samuel Holland <samuel.holland@xxxxxxxxxx>
---
Changes in v2:
- New patch for v2
arch/riscv/include/asm/cpufeature.h | 1 +
arch/riscv/include/asm/hwcap.h | 8 ++++++
arch/riscv/kernel/cpu.c | 5 ++++
arch/riscv/kernel/cpufeature.c | 42 +++++++++++++++++++++++++----
4 files changed, 51 insertions(+), 5 deletions(-)
diff --git a/arch/riscv/include/asm/cpufeature.h b/arch/riscv/include/asm/cpufeature.h
index 0bd11862b760..ac71384e7bc4 100644
--- a/arch/riscv/include/asm/cpufeature.h
+++ b/arch/riscv/include/asm/cpufeature.h
@@ -61,6 +61,7 @@ struct riscv_isa_ext_data {
const char *property;
const unsigned int *subset_ext_ids;
const unsigned int subset_ext_size;
+ const unsigned int successor_id;
};
extern const struct riscv_isa_ext_data riscv_isa_ext[];
diff --git a/arch/riscv/include/asm/hwcap.h b/arch/riscv/include/asm/hwcap.h
index 5340f818746b..5b51aa1db15b 100644
--- a/arch/riscv/include/asm/hwcap.h
+++ b/arch/riscv/include/asm/hwcap.h
@@ -80,13 +80,21 @@
#define RISCV_ISA_EXT_ZFA 71
#define RISCV_ISA_EXT_ZTSO 72
#define RISCV_ISA_EXT_ZACAS 73
+#define RISCV_ISA_EXT_SM1p11 74
+#define RISCV_ISA_EXT_SM1p12 75
+#define RISCV_ISA_EXT_SS1p11 76
+#define RISCV_ISA_EXT_SS1p12 77
#define RISCV_ISA_EXT_MAX 128
#define RISCV_ISA_EXT_INVALID U32_MAX
#ifdef CONFIG_RISCV_M_MODE
+#define RISCV_ISA_EXT_Sx1p11 RISCV_ISA_EXT_SM1p11
+#define RISCV_ISA_EXT_Sx1p12 RISCV_ISA_EXT_SM1p12
#define RISCV_ISA_EXT_SxAIA RISCV_ISA_EXT_SMAIA
#else
+#define RISCV_ISA_EXT_Sx1p11 RISCV_ISA_EXT_SS1p11
+#define RISCV_ISA_EXT_Sx1p12 RISCV_ISA_EXT_SS1p12
#define RISCV_ISA_EXT_SxAIA RISCV_ISA_EXT_SSAIA
#endif
diff --git a/arch/riscv/kernel/cpu.c b/arch/riscv/kernel/cpu.c
index d11d6320fb0d..2e6b90ed0d51 100644
--- a/arch/riscv/kernel/cpu.c
+++ b/arch/riscv/kernel/cpu.c
@@ -215,6 +215,11 @@ static void print_isa(struct seq_file *f, const unsigned long *isa_bitmap)
if (!__riscv_isa_extension_available(isa_bitmap, riscv_isa_ext[i].id))
continue;
+ /* Only show the newest implemented version of an extension */
+ if (riscv_isa_ext[i].successor_id != RISCV_ISA_EXT_INVALID &&
+ __riscv_isa_extension_available(isa_bitmap, riscv_isa_ext[i].successor_id))
+ continue;
+
/* Only multi-letter extensions are split by underscores */
if (strnlen(riscv_isa_ext[i].name, 2) != 1)
seq_puts(f, "_");
diff --git a/arch/riscv/kernel/cpufeature.c b/arch/riscv/kernel/cpufeature.c
index c5b13f7dd482..8e10b50120e9 100644
--- a/arch/riscv/kernel/cpufeature.c
+++ b/arch/riscv/kernel/cpufeature.c
@@ -113,23 +113,29 @@ static bool riscv_isa_extension_check(int id)
return true;
}
-#define _RISCV_ISA_EXT_DATA(_name, _id, _subset_exts, _subset_exts_size) { \
+#define _RISCV_ISA_EXT_DATA(_name, _id, _subset_exts, _subset_exts_size, _successor) { \
.name = #_name, \
.property = #_name, \
.id = _id, \
.subset_ext_ids = _subset_exts, \
- .subset_ext_size = _subset_exts_size \
+ .subset_ext_size = _subset_exts_size, \
+ .successor_id = _successor, \
}
-#define __RISCV_ISA_EXT_DATA(_name, _id) _RISCV_ISA_EXT_DATA(_name, _id, NULL, 0)
+#define __RISCV_ISA_EXT_DATA(_name, _id) \
+ _RISCV_ISA_EXT_DATA(_name, _id, NULL, 0, RISCV_ISA_EXT_INVALID)
/* Used to declare pure "lasso" extension (Zk for instance) */
#define __RISCV_ISA_EXT_BUNDLE(_name, _bundled_exts) \
- _RISCV_ISA_EXT_DATA(_name, RISCV_ISA_EXT_INVALID, _bundled_exts, ARRAY_SIZE(_bundled_exts))
+ _RISCV_ISA_EXT_DATA(_name, RISCV_ISA_EXT_INVALID, \
+ _bundled_exts, ARRAY_SIZE(_bundled_exts), RISCV_ISA_EXT_INVALID)
/* Used to declare extensions that are a superset of other extensions (Zvbb for instance) */
#define __RISCV_ISA_EXT_SUPERSET(_name, _id, _sub_exts) \
- _RISCV_ISA_EXT_DATA(_name, _id, _sub_exts, ARRAY_SIZE(_sub_exts))
+ _RISCV_ISA_EXT_DATA(_name, _id, _sub_exts, ARRAY_SIZE(_sub_exts), RISCV_ISA_EXT_INVALID)
+
+#define __RISCV_ISA_EXT_VERSION(_name, _id, _preds, _preds_size, _successor) \
+ _RISCV_ISA_EXT_DATA(_name, _id, _preds, _preds_size, _successor)
static const unsigned int riscv_zk_bundled_exts[] = {
RISCV_ISA_EXT_ZBKB,
@@ -201,6 +207,16 @@ static const unsigned int riscv_zvbb_exts[] = {
RISCV_ISA_EXT_ZVKB
};
+static const unsigned int riscv_sm_ext_versions[] = {
+ RISCV_ISA_EXT_SM1p11,
+ RISCV_ISA_EXT_SM1p12,
+};
+
+static const unsigned int riscv_ss_ext_versions[] = {
+ RISCV_ISA_EXT_SS1p11,
+ RISCV_ISA_EXT_SS1p12,
+};
+
/*
* The canonical order of ISA extension names in the ISA string is defined in
* chapter 27 of the unprivileged specification.
@@ -299,8 +315,16 @@ const struct riscv_isa_ext_data riscv_isa_ext[] = {
__RISCV_ISA_EXT_DATA(zvksh, RISCV_ISA_EXT_ZVKSH),
__RISCV_ISA_EXT_BUNDLE(zvksg, riscv_zvksg_bundled_exts),
__RISCV_ISA_EXT_DATA(zvkt, RISCV_ISA_EXT_ZVKT),
+ __RISCV_ISA_EXT_VERSION(sm1p11, RISCV_ISA_EXT_SM1p11, riscv_sm_ext_versions, 0,
+ RISCV_ISA_EXT_SM1p12),
+ __RISCV_ISA_EXT_VERSION(sm1p12, RISCV_ISA_EXT_SM1p12, riscv_sm_ext_versions, 1,
+ RISCV_ISA_EXT_INVALID),
__RISCV_ISA_EXT_DATA(smaia, RISCV_ISA_EXT_SMAIA),
__RISCV_ISA_EXT_DATA(smstateen, RISCV_ISA_EXT_SMSTATEEN),
+ __RISCV_ISA_EXT_VERSION(ss1p11, RISCV_ISA_EXT_SS1p11, riscv_ss_ext_versions, 0,
+ RISCV_ISA_EXT_SS1p12),
+ __RISCV_ISA_EXT_VERSION(ss1p12, RISCV_ISA_EXT_SS1p12, riscv_ss_ext_versions, 1,
+ RISCV_ISA_EXT_INVALID),
__RISCV_ISA_EXT_DATA(ssaia, RISCV_ISA_EXT_SSAIA),
__RISCV_ISA_EXT_DATA(sscofpmf, RISCV_ISA_EXT_SSCOFPMF),
__RISCV_ISA_EXT_DATA(sstc, RISCV_ISA_EXT_SSTC),
@@ -414,6 +438,14 @@ static void __init riscv_parse_isa_string(unsigned long *this_hwcap, struct risc
;
++ext_end;
+
+ /*
+ * As a special case for the Sm and Ss extensions, where the version
+ * number is important, include it in the extension name.
+ */
+ if (ext_end - ext == 2 && tolower(ext[0]) == 's' &&
+ (tolower(ext[1]) == 'm' || tolower(ext[1]) == 's'))
+ ext_end = isa;
break;
default:
/*
--
2.43.0