* [PATCH] riscv: Avoid io read/write cause wrong result
@ 2021-10-18 3:50 Nick Hu
2021-10-19 8:30 ` Leo Liang
2021-10-19 8:59 ` Bin Meng
0 siblings, 2 replies; 3+ messages in thread
From: Nick Hu @ 2021-10-18 3:50 UTC (permalink / raw)
To: u-boot, rick, ycliang, greentime.hu, zong.li, vincent.chen; +Cc: Nick Hu
io read/write may cause wrong result because they may read/write data
from/to register instead of memory. Add 'volatile' to avoid it.
Signed-off-by: Nick Hu <nick.hu@sifive.com>
---
arch/riscv/include/asm/io.h | 18 +++++++++---------
1 file changed, 9 insertions(+), 9 deletions(-)
diff --git a/arch/riscv/include/asm/io.h b/arch/riscv/include/asm/io.h
index acf5a96449..3540773c4f 100644
--- a/arch/riscv/include/asm/io.h
+++ b/arch/riscv/include/asm/io.h
@@ -44,15 +44,15 @@ static inline phys_addr_t map_to_sysmem(const void *ptr)
* read/writes. We define __arch_*[bl] here, and leave __arch_*w
* to the architecture specific code.
*/
-#define __arch_getb(a) (*(unsigned char *)(a))
-#define __arch_getw(a) (*(unsigned short *)(a))
-#define __arch_getl(a) (*(unsigned int *)(a))
-#define __arch_getq(a) (*(unsigned long long *)(a))
-
-#define __arch_putb(v, a) (*(unsigned char *)(a) = (v))
-#define __arch_putw(v, a) (*(unsigned short *)(a) = (v))
-#define __arch_putl(v, a) (*(unsigned int *)(a) = (v))
-#define __arch_putq(v, a) (*(unsigned long long *)(a) = (v))
+#define __arch_getb(a) (*(volatile unsigned char *)(a))
+#define __arch_getw(a) (*(volatile unsigned short *)(a))
+#define __arch_getl(a) (*(volatile unsigned int *)(a))
+#define __arch_getq(a) (*(volatile unsigned long long *)(a))
+
+#define __arch_putb(v, a) (*(volatile unsigned char *)(a) = (v))
+#define __arch_putw(v, a) (*(volatile unsigned short *)(a) = (v))
+#define __arch_putl(v, a) (*(volatile unsigned int *)(a) = (v))
+#define __arch_putq(v, a) (*(volatile unsigned long long *)(a) = (v))
#define __raw_writeb(v, a) __arch_putb(v, a)
#define __raw_writew(v, a) __arch_putw(v, a)
--
2.31.1
^ permalink raw reply related [flat|nested] 3+ messages in thread
* Re: [PATCH] riscv: Avoid io read/write cause wrong result
2021-10-18 3:50 [PATCH] riscv: Avoid io read/write cause wrong result Nick Hu
@ 2021-10-19 8:30 ` Leo Liang
2021-10-19 8:59 ` Bin Meng
1 sibling, 0 replies; 3+ messages in thread
From: Leo Liang @ 2021-10-19 8:30 UTC (permalink / raw)
To: Nick Hu; +Cc: u-boot, rick, greentime.hu, zong.li, vincent.chen
On Mon, Oct 18, 2021 at 11:50:05AM +0800, Nick Hu wrote:
> io read/write may cause wrong result because they may read/write data
> from/to register instead of memory. Add 'volatile' to avoid it.
>
> Signed-off-by: Nick Hu <nick.hu@sifive.com>
> ---
> arch/riscv/include/asm/io.h | 18 +++++++++---------
> 1 file changed, 9 insertions(+), 9 deletions(-)
>
Reviewed-by: Leo Yu-Chi Liang <ycliang@andestech.com>
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH] riscv: Avoid io read/write cause wrong result
2021-10-18 3:50 [PATCH] riscv: Avoid io read/write cause wrong result Nick Hu
2021-10-19 8:30 ` Leo Liang
@ 2021-10-19 8:59 ` Bin Meng
1 sibling, 0 replies; 3+ messages in thread
From: Bin Meng @ 2021-10-19 8:59 UTC (permalink / raw)
To: Nick Hu
Cc: U-Boot Mailing List, Rick Chen, Leo Yu-Chi Liang, Greentime Hu,
Zong Li, Vincent Chen
On Mon, Oct 18, 2021 at 7:31 PM Nick Hu <nick.hu@sifive.com> wrote:
>
> io read/write may cause wrong result because they may read/write data
> from/to register instead of memory. Add 'volatile' to avoid it.
>
> Signed-off-by: Nick Hu <nick.hu@sifive.com>
> ---
> arch/riscv/include/asm/io.h | 18 +++++++++---------
> 1 file changed, 9 insertions(+), 9 deletions(-)
>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
^ permalink raw reply [flat|nested] 3+ messages in thread
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