RISC-V: repurpose riscv_isa_ext array in riscv_fill_hwcap()

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@ventanamicro.com>
Signed-off-by: Conor Dooley <conor.dooley@microchip.com>
Link: https://lore.kernel.org/r/20230713-dastardly-affiliate-4cf819dccde2@wendy
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>

diff --git a/arch/riscv/include/asm/hwcap.h b/arch/riscv/include/asm/hwcap.h
index 7a57e61..2460ac2 100644 (file)
--- 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 bf93293..aa17eeb 100644 (file)
--- 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 fb47615..859e383 100644 (file)
--- 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
                }