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[01/11] lib: sbi: Fix sbi_hart_switch_mode() for u-mode

Message ID 20201121094756.4154728-2-anup.patel@wdc.com
State Superseded
Headers show
Series OpenSBI domain configuration using device tree | expand

Commit Message

Anup Patel Nov. 21, 2020, 9:47 a.m. UTC 
We should check and access N-extension CSRs in sbi_hart_switch_mode()
when next_mode is u-mode because N-extension is optional.

Signed-off-by: Anup Patel <anup.patel@wdc.com>
---
 lib/sbi/sbi_hart.c | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

Comments

Alistair Francis Dec. 1, 2020, 1:58 a.m. UTC | #1 
On Sat, 2020-11-21 at 15:17 +0530, Anup Patel wrote:
> We should check and access N-extension CSRs in sbi_hart_switch_mode()
> when next_mode is u-mode because N-extension is optional.
> 
> Signed-off-by: Anup Patel <anup.patel@wdc.com>

Reviewed-by: Alistair Francis <alistair.francis@wdc.com>

Alistair

> ---
>  lib/sbi/sbi_hart.c | 8 +++++---
>  1 file changed, 5 insertions(+), 3 deletions(-)
> 
> diff --git a/lib/sbi/sbi_hart.c b/lib/sbi/sbi_hart.c
> index 30d8aef..fc86e9f 100644
> --- a/lib/sbi/sbi_hart.c
> +++ b/lib/sbi/sbi_hart.c
> @@ -522,9 +522,11 @@ sbi_hart_switch_mode(unsigned long arg0,
> unsigned long arg1,
>                 csr_write(CSR_SIE, 0);
>                 csr_write(CSR_SATP, 0);
>         } else if (next_mode == PRV_U) {
> -               csr_write(CSR_UTVEC, next_addr);
> -               csr_write(CSR_USCRATCH, 0);
> -               csr_write(CSR_UIE, 0);
> +               if (misa_extension('N')) {
> +                       csr_write(CSR_UTVEC, next_addr);
> +                       csr_write(CSR_USCRATCH, 0);
> +                       csr_write(CSR_UIE, 0);
> +               }
>         }
>  
>         register unsigned long a0 asm("a0") = arg0;
Atish Patra Dec. 3, 2020, 11:48 p.m. UTC | #2 
On Sat, Nov 21, 2020 at 2:52 PM Anup Patel <anup.patel@wdc.com> wrote:
>
> We should check and access N-extension CSRs in sbi_hart_switch_mode()
> when next_mode is u-mode because N-extension is optional.
>
> Signed-off-by: Anup Patel <anup.patel@wdc.com>
> ---
>  lib/sbi/sbi_hart.c | 8 +++++---
>  1 file changed, 5 insertions(+), 3 deletions(-)
>
> diff --git a/lib/sbi/sbi_hart.c b/lib/sbi/sbi_hart.c
> index 30d8aef..fc86e9f 100644
> --- a/lib/sbi/sbi_hart.c
> +++ b/lib/sbi/sbi_hart.c
> @@ -522,9 +522,11 @@ sbi_hart_switch_mode(unsigned long arg0, unsigned long arg1,
>                 csr_write(CSR_SIE, 0);
>                 csr_write(CSR_SATP, 0);
>         } else if (next_mode == PRV_U) {
> -               csr_write(CSR_UTVEC, next_addr);
> -               csr_write(CSR_USCRATCH, 0);
> -               csr_write(CSR_UIE, 0);
> +               if (misa_extension('N')) {
> +                       csr_write(CSR_UTVEC, next_addr);
> +                       csr_write(CSR_USCRATCH, 0);
> +                       csr_write(CSR_UIE, 0);
> +               }
>         }
>
>         register unsigned long a0 asm("a0") = arg0;
> --
> 2.25.1
>
>
> --
> opensbi mailing list
> opensbi@lists.infradead.org
> http://lists.infradead.org/mailman/listinfo/opensbi


Reviewed-by: Atish Patra <atish.patra@wdc.com>
diff mbox series

Patch

diff --git a/lib/sbi/sbi_hart.c b/lib/sbi/sbi_hart.c
index 30d8aef..fc86e9f 100644
--- a/lib/sbi/sbi_hart.c
+++ b/lib/sbi/sbi_hart.c
@@ -522,9 +522,11 @@  sbi_hart_switch_mode(unsigned long arg0, unsigned long arg1,
 		csr_write(CSR_SIE, 0);
 		csr_write(CSR_SATP, 0);
 	} else if (next_mode == PRV_U) {
-		csr_write(CSR_UTVEC, next_addr);
-		csr_write(CSR_USCRATCH, 0);
-		csr_write(CSR_UIE, 0);
+		if (misa_extension('N')) {
+			csr_write(CSR_UTVEC, next_addr);
+			csr_write(CSR_USCRATCH, 0);
+			csr_write(CSR_UIE, 0);
+		}
 	}
 
 	register unsigned long a0 asm("a0") = arg0;