diff mbox series

[v3,1/3] RISC-V: Correctly print supported extensions

Message ID d4d5a22e24d477ab4d8284d0140e17c6c5ff5464.1644647398.git.research_trasio@irq.a4lg.com (mailing list archive)
State New, archived
Headers show
Series [v3,1/3] RISC-V: Correctly print supported extensions | expand

Commit Message

Tsukasa OI Feb. 12, 2022, 6:29 a.m. UTC 
This commit replaces BITS_PER_LONG with number of alphabet letters.

Current ISA pretty-printing code expects extension 'a' (bit 0) through
'z' (bit 25).  Although bit 26 and higher is not currently used (thus never
cause an issue in practice), it will be an annoying problem if we start to
use those in the future.

This commit disables printing high bits for now.

Signed-off-by: Tsukasa OI <research_trasio@irq.a4lg.com>
Signed-off-by: Atish Patra <atishp@rivosinc.com>
---
 arch/riscv/kernel/cpufeature.c | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)


base-commit: 7aed1489bdf879da403e8ee9d6d77b0be26bb84d

Comments

Heiko Stübner Feb. 14, 2022, 8:04 p.m. UTC | #1 
Am Samstag, 12. Februar 2022, 07:29:59 CET schrieb Tsukasa OI:
> This commit replaces BITS_PER_LONG with number of alphabet letters.
> 
> Current ISA pretty-printing code expects extension 'a' (bit 0) through
> 'z' (bit 25).  Although bit 26 and higher is not currently used (thus never
> cause an issue in practice), it will be an annoying problem if we start to
> use those in the future.
> 
> This commit disables printing high bits for now.
> 
> Signed-off-by: Tsukasa OI <research_trasio@irq.a4lg.com>
> Signed-off-by: Atish Patra <atishp@rivosinc.com>

Tested-by: Heiko Stuebner <heiko@sntech.de>

> ---
>  arch/riscv/kernel/cpufeature.c | 8 +++++---
>  1 file changed, 5 insertions(+), 3 deletions(-)
> 
> diff --git a/arch/riscv/kernel/cpufeature.c b/arch/riscv/kernel/cpufeature.c
> index d959d207a40d..dd3d57eb4eea 100644
> --- a/arch/riscv/kernel/cpufeature.c
> +++ b/arch/riscv/kernel/cpufeature.c
> @@ -13,6 +13,8 @@
>  #include <asm/smp.h>
>  #include <asm/switch_to.h>
>  
> +#define NUM_ALPHA_EXTS ('z' - 'a' + 1)
> +
>  unsigned long elf_hwcap __read_mostly;
>  
>  /* Host ISA bitmap */
> @@ -63,7 +65,7 @@ void __init riscv_fill_hwcap(void)
>  {
>  	struct device_node *node;
>  	const char *isa;
> -	char print_str[BITS_PER_LONG + 1];
> +	char print_str[NUM_ALPHA_EXTS + 1];
>  	size_t i, j, isa_len;
>  	static unsigned long isa2hwcap[256] = {0};
>  
> @@ -133,13 +135,13 @@ void __init riscv_fill_hwcap(void)
>  	}
>  
>  	memset(print_str, 0, sizeof(print_str));
> -	for (i = 0, j = 0; i < BITS_PER_LONG; i++)
> +	for (i = 0, j = 0; i < NUM_ALPHA_EXTS; i++)
>  		if (riscv_isa[0] & BIT_MASK(i))
>  			print_str[j++] = (char)('a' + i);
>  	pr_info("riscv: ISA extensions %s\n", print_str);
>  
>  	memset(print_str, 0, sizeof(print_str));
> -	for (i = 0, j = 0; i < BITS_PER_LONG; i++)
> +	for (i = 0, j = 0; i < NUM_ALPHA_EXTS; i++)
>  		if (elf_hwcap & BIT_MASK(i))
>  			print_str[j++] = (char)('a' + i);
>  	pr_info("riscv: ELF capabilities %s\n", print_str);
> 
> base-commit: 7aed1489bdf879da403e8ee9d6d77b0be26bb84d
>
diff mbox series

Patch

diff --git a/arch/riscv/kernel/cpufeature.c b/arch/riscv/kernel/cpufeature.c
index d959d207a40d..dd3d57eb4eea 100644
--- a/arch/riscv/kernel/cpufeature.c
+++ b/arch/riscv/kernel/cpufeature.c
@@ -13,6 +13,8 @@ 
 #include <asm/smp.h>
 #include <asm/switch_to.h>
 
+#define NUM_ALPHA_EXTS ('z' - 'a' + 1)
+
 unsigned long elf_hwcap __read_mostly;
 
 /* Host ISA bitmap */
@@ -63,7 +65,7 @@  void __init riscv_fill_hwcap(void)
 {
 	struct device_node *node;
 	const char *isa;
-	char print_str[BITS_PER_LONG + 1];
+	char print_str[NUM_ALPHA_EXTS + 1];
 	size_t i, j, isa_len;
 	static unsigned long isa2hwcap[256] = {0};
 
@@ -133,13 +135,13 @@  void __init riscv_fill_hwcap(void)
 	}
 
 	memset(print_str, 0, sizeof(print_str));
-	for (i = 0, j = 0; i < BITS_PER_LONG; i++)
+	for (i = 0, j = 0; i < NUM_ALPHA_EXTS; i++)
 		if (riscv_isa[0] & BIT_MASK(i))
 			print_str[j++] = (char)('a' + i);
 	pr_info("riscv: ISA extensions %s\n", print_str);
 
 	memset(print_str, 0, sizeof(print_str));
-	for (i = 0, j = 0; i < BITS_PER_LONG; i++)
+	for (i = 0, j = 0; i < NUM_ALPHA_EXTS; i++)
 		if (elf_hwcap & BIT_MASK(i))
 			print_str[j++] = (char)('a' + i);
 	pr_info("riscv: ELF capabilities %s\n", print_str);