[PATCH v5 05/11] RISC-V: repurpose riscv_isa_ext array in riscv_fill_hwcap()

From: Conor Dooley
Date: Thu Jul 13 2023 - 08:13:33 EST


In riscv_fill_hwcap() riscv_isa_ext array can be looped over, rather
than duplicating the list of extensions with individual
SET_ISA_EXT_MAP() usage. While at it, drop the statement-of-the-obvious
comments from the struct, rename uprop to something more suitable for
its new use & constify the members.

Reviewed-by: Andrew Jones <ajones@xxxxxxxxxxxxxxxx>
Signed-off-by: Conor Dooley <conor.dooley@xxxxxxxxxxxxx>
---
Changes in v5:
- Swap sizeof() - 1 for strlen() as pointed out by Evan

Changes in v2:
- Delete the now unused definition
---
arch/riscv/include/asm/hwcap.h | 7 ++-----
arch/riscv/kernel/cpu.c | 5 +++--
arch/riscv/kernel/cpufeature.c | 30 +++++++++---------------------
3 files changed, 14 insertions(+), 28 deletions(-)

diff --git a/arch/riscv/include/asm/hwcap.h b/arch/riscv/include/asm/hwcap.h
index 7a57e6109aef..2460ac2fc7ed 100644
--- a/arch/riscv/include/asm/hwcap.h
+++ b/arch/riscv/include/asm/hwcap.h
@@ -55,7 +55,6 @@
#define RISCV_ISA_EXT_ZIHPM 42

#define RISCV_ISA_EXT_MAX 64
-#define RISCV_ISA_EXT_NAME_LEN_MAX 32

#ifdef CONFIG_RISCV_M_MODE
#define RISCV_ISA_EXT_SxAIA RISCV_ISA_EXT_SMAIA
@@ -70,10 +69,8 @@
unsigned long riscv_get_elf_hwcap(void);

struct riscv_isa_ext_data {
- /* Name of the extension displayed to userspace via /proc/cpuinfo */
- char uprop[RISCV_ISA_EXT_NAME_LEN_MAX];
- /* The logical ISA extension ID */
- unsigned int isa_ext_id;
+ const unsigned int id;
+ const char *name;
};

extern const struct riscv_isa_ext_data riscv_isa_ext[];
diff --git a/arch/riscv/kernel/cpu.c b/arch/riscv/kernel/cpu.c
index bf93293d51f3..aa17eeb0ec9a 100644
--- a/arch/riscv/kernel/cpu.c
+++ b/arch/riscv/kernel/cpu.c
@@ -168,9 +168,10 @@ static void print_isa_ext(struct seq_file *f)
{
for (int i = 0; i < riscv_isa_ext_count; i++) {
const struct riscv_isa_ext_data *edata = &riscv_isa_ext[i];
- if (!__riscv_isa_extension_available(NULL, edata->isa_ext_id))
+ if (!__riscv_isa_extension_available(NULL, edata->id))
continue;
- seq_printf(f, "_%s", edata->uprop);
+
+ seq_printf(f, "_%s", edata->name);
}
}

diff --git a/arch/riscv/kernel/cpufeature.c b/arch/riscv/kernel/cpufeature.c
index fb476153fffc..859e3831fac1 100644
--- a/arch/riscv/kernel/cpufeature.c
+++ b/arch/riscv/kernel/cpufeature.c
@@ -99,11 +99,10 @@ static bool riscv_isa_extension_check(int id)
return true;
}

-#define __RISCV_ISA_EXT_DATA(UPROP, EXTID) \
- { \
- .uprop = #UPROP, \
- .isa_ext_id = EXTID, \
- }
+#define __RISCV_ISA_EXT_DATA(_name, _id) { \
+ .name = #_name, \
+ .id = _id, \
+}

/*
* The canonical order of ISA extension names in the ISA string is defined in
@@ -350,8 +349,8 @@ void __init riscv_fill_hwcap(void)

#define SET_ISA_EXT_MAP(name, bit) \
do { \
- if ((ext_end - ext == sizeof(name) - 1) && \
- !strncasecmp(ext, name, sizeof(name) - 1) && \
+ if ((ext_end - ext == strlen(name)) && \
+ !strncasecmp(ext, name, strlen(name)) && \
riscv_isa_extension_check(bit)) \
set_bit(bit, isainfo->isa); \
} while (false) \
@@ -366,20 +365,9 @@ void __init riscv_fill_hwcap(void)
set_bit(nr, isainfo->isa);
}
} else {
- /* sorted alphabetically */
- SET_ISA_EXT_MAP("smaia", RISCV_ISA_EXT_SMAIA);
- SET_ISA_EXT_MAP("ssaia", RISCV_ISA_EXT_SSAIA);
- SET_ISA_EXT_MAP("sscofpmf", RISCV_ISA_EXT_SSCOFPMF);
- SET_ISA_EXT_MAP("sstc", RISCV_ISA_EXT_SSTC);
- SET_ISA_EXT_MAP("svinval", RISCV_ISA_EXT_SVINVAL);
- SET_ISA_EXT_MAP("svnapot", RISCV_ISA_EXT_SVNAPOT);
- SET_ISA_EXT_MAP("svpbmt", RISCV_ISA_EXT_SVPBMT);
- SET_ISA_EXT_MAP("zba", RISCV_ISA_EXT_ZBA);
- SET_ISA_EXT_MAP("zbb", RISCV_ISA_EXT_ZBB);
- SET_ISA_EXT_MAP("zbs", RISCV_ISA_EXT_ZBS);
- SET_ISA_EXT_MAP("zicbom", RISCV_ISA_EXT_ZICBOM);
- SET_ISA_EXT_MAP("zicboz", RISCV_ISA_EXT_ZICBOZ);
- SET_ISA_EXT_MAP("zihintpause", RISCV_ISA_EXT_ZIHINTPAUSE);
+ for (int i = 0; i < riscv_isa_ext_count; i++)
+ SET_ISA_EXT_MAP(riscv_isa_ext[i].name,
+ riscv_isa_ext[i].id);
}
#undef SET_ISA_EXT_MAP
}
--
2.40.1