riscv: allow case-insensitive ISA string parsing

According to RISC-V Hart Capabilities Table (RHCT) description in UEFI
Forum ECR, the format of the ISA string is defined in the RISC-V
unprivileged specification which is case-insensitive. However, the
current ISA string parser in the kernel does not support ISA strings
with uppercase letters.

This patch modifies the ISA string parser in the kernel to support
case-insensitive ISA string parsing.

Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
Reviewed-by: Conor Dooley <conor.dooley@microchip.com>
Signed-off-by: Yangyu Chen <cyy@cyyself.name>
Link: https://lore.kernel.org/r/tencent_B30EED51C7235CA1988890E5C658BE35C107@qq.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>

diff --git a/arch/riscv/kernel/cpu.c b/arch/riscv/kernel/cpu.c
index c96aa56..9d3a536 100644 (file)
--- a/arch/riscv/kernel/cpu.c
+++ b/arch/riscv/kernel/cpu.c
@@ -4,6 +4,7 @@
  */
 
 #include <linux/cpu.h>
+#include <linux/ctype.h>
 #include <linux/init.h>
 #include <linux/seq_file.h>
 #include <linux/of.h>
@@ -42,7 +43,7 @@ int riscv_of_processor_hartid(struct device_node *node, unsigned long *hart)
                pr_warn("CPU with hartid=%lu has no \"riscv,isa\" property\n", *hart);
                return -ENODEV;
        }
-       if (isa[0] != 'r' || isa[1] != 'v') {
+       if (tolower(isa[0]) != 'r' || tolower(isa[1]) != 'v') {
                pr_warn("CPU with hartid=%lu has an invalid ISA of \"%s\"\n", *hart, isa);
                return -ENODEV;
        }

diff --git a/arch/riscv/kernel/cpufeature.c b/arch/riscv/kernel/cpufeature.c
index b1d6b7e..1576879 100644 (file)
--- a/arch/riscv/kernel/cpufeature.c
+++ b/arch/riscv/kernel/cpufeature.c
@@ -127,13 +127,10 @@ void __init riscv_fill_hwcap(void)
                }
 
                temp = isa;
-#if IS_ENABLED(CONFIG_32BIT)
-               if (!strncmp(isa, "rv32", 4))
+               if (IS_ENABLED(CONFIG_32BIT) && !strncasecmp(isa, "rv32", 4))
                        isa += 4;
-#elif IS_ENABLED(CONFIG_64BIT)
-               if (!strncmp(isa, "rv64", 4))
+               else if (IS_ENABLED(CONFIG_64BIT) && !strncasecmp(isa, "rv64", 4))
                        isa += 4;
-#endif
                /* The riscv,isa DT property must start with rv64 or rv32 */
                if (temp == isa)
                        continue;
@@ -157,13 +154,15 @@ void __init riscv_fill_hwcap(void)
                                        break;
                                }
                                fallthrough;
+                       case 'S':
                        case 'x':
+                       case 'X':
                        case 'z':
+                       case 'Z':
                                ext_long = true;
                                /* Multi-letter extension must be delimited */
                                for (; *isa && *isa != '_'; ++isa)
-                                       if (unlikely(!islower(*isa)
-                                                    && !isdigit(*isa)))
+                                       if (unlikely(!isalnum(*isa)))
                                                ext_err = true;
                                /* Parse backwards */
                                ext_end = isa;
@@ -174,7 +173,7 @@ void __init riscv_fill_hwcap(void)
                                /* Skip the minor version */
                                while (isdigit(*--ext_end))
                                        ;
-                               if (ext_end[0] != 'p'
+                               if (tolower(ext_end[0]) != 'p'
                                    || !isdigit(ext_end[-1])) {
                                        /* Advance it to offset the pre-decrement */
                                        ++ext_end;
@@ -186,7 +185,7 @@ void __init riscv_fill_hwcap(void)
                                ++ext_end;
                                break;
                        default:
-                               if (unlikely(!islower(*ext))) {
+                               if (unlikely(!isalpha(*ext))) {
                                        ext_err = true;
                                        break;
                                }
@@ -196,7 +195,7 @@ void __init riscv_fill_hwcap(void)
                                /* Skip the minor version */
                                while (isdigit(*++isa))
                                        ;
-                               if (*isa != 'p')
+                               if (tolower(*isa) != 'p')
                                        break;
                                if (!isdigit(*++isa)) {
                                        --isa;
@@ -210,18 +209,18 @@ void __init riscv_fill_hwcap(void)
                        if (*isa != '_')
                                --isa;
 
-#define SET_ISA_EXT_MAP(name, bit)                                             \
-                       do {                                                    \
-                               if ((ext_end - ext == sizeof(name) - 1) &&      \
-                                    !memcmp(ext, name, sizeof(name) - 1) &&    \
-                                    riscv_isa_extension_check(bit))            \
-                                       set_bit(bit, this_isa);                 \
-                       } while (false)                                         \
+#define SET_ISA_EXT_MAP(name, bit)                                                     \
+                       do {                                                            \
+                               if ((ext_end - ext == sizeof(name) - 1) &&              \
+                                    !strncasecmp(ext, name, sizeof(name) - 1) &&       \
+                                    riscv_isa_extension_check(bit))                    \
+                                       set_bit(bit, this_isa);                         \
+                       } while (false)                                                 \
 
                        if (unlikely(ext_err))
                                continue;
                        if (!ext_long) {
-                               int nr = *ext - 'a';
+                               int nr = tolower(*ext) - 'a';
 
                                if (riscv_isa_extension_check(nr)) {
                                        this_hwcap |= isa2hwcap[nr];