* [PATCH] riscv: mm: don't advertise 1 num_asid for 0 asid bits
@ 2021-09-07 20:02 Vineet Gupta
2021-09-08 8:35 ` Anup Patel
0 siblings, 1 reply; 4+ messages in thread
From: Vineet Gupta @ 2021-09-07 20:02 UTC (permalink / raw)
To: Paul Walmsley, Palmer Dabbelt, Albert Ou, Anup Patel,
Jisheng Zhang, Guo Ren, Kefeng Wang
Cc: linux-riscv, linux-kernel, Vineet Gupta
Even if mmu doesn't support ASID, current code calculates @num_asids=1
which is misleading, so avoid setting any asid related variables in such
a case.
Also while here, print the number of asid bits discovered even for the
disabled case.
Verified this on Hifive Unmatched.
Signed-off-by: Vineet Gupta <vgupta@kernel.org>
---
arch/riscv/mm/context.c | 8 +++++---
1 file changed, 5 insertions(+), 3 deletions(-)
diff --git a/arch/riscv/mm/context.c b/arch/riscv/mm/context.c
index ee3459cb6750..c8c6f8831a3b 100644
--- a/arch/riscv/mm/context.c
+++ b/arch/riscv/mm/context.c
@@ -233,8 +233,10 @@ static int __init asids_init(void)
local_flush_tlb_all();
/* Pre-compute ASID details */
- num_asids = 1 << asid_bits;
- asid_mask = num_asids - 1;
+ if (asid_bits) {
+ num_asids = 1 << asid_bits;
+ asid_mask = num_asids - 1;
+ }
/*
* Use ASID allocator only if number of HW ASIDs are
@@ -255,7 +257,7 @@ static int __init asids_init(void)
pr_info("ASID allocator using %lu bits (%lu entries)\n",
asid_bits, num_asids);
} else {
- pr_info("ASID allocator disabled\n");
+ pr_info("ASID allocator disabled: %lu bits\n", asid_bits);
}
return 0;
--
2.30.2
^ permalink raw reply related [flat|nested] 4+ messages in thread
* Re: [PATCH] riscv: mm: don't advertise 1 num_asid for 0 asid bits
2021-09-07 20:02 [PATCH] riscv: mm: don't advertise 1 num_asid for 0 asid bits Vineet Gupta
@ 2021-09-08 8:35 ` Anup Patel
2021-09-08 17:30 ` [PATCH v2] " Vineet Gupta
0 siblings, 1 reply; 4+ messages in thread
From: Anup Patel @ 2021-09-08 8:35 UTC (permalink / raw)
To: Vineet Gupta
Cc: Paul Walmsley, Palmer Dabbelt, Albert Ou, Anup Patel,
Jisheng Zhang, Guo Ren, Kefeng Wang, linux-riscv,
linux-kernel@vger.kernel.org List
On Wed, Sep 8, 2021 at 1:33 AM Vineet Gupta <vgupta@kernel.org> wrote:
>
> Even if mmu doesn't support ASID, current code calculates @num_asids=1
> which is misleading, so avoid setting any asid related variables in such
> a case.
>
> Also while here, print the number of asid bits discovered even for the
> disabled case.
>
> Verified this on Hifive Unmatched.
>
> Signed-off-by: Vineet Gupta <vgupta@kernel.org>
> ---
> arch/riscv/mm/context.c | 8 +++++---
> 1 file changed, 5 insertions(+), 3 deletions(-)
>
> diff --git a/arch/riscv/mm/context.c b/arch/riscv/mm/context.c
> index ee3459cb6750..c8c6f8831a3b 100644
> --- a/arch/riscv/mm/context.c
> +++ b/arch/riscv/mm/context.c
> @@ -233,8 +233,10 @@ static int __init asids_init(void)
> local_flush_tlb_all();
>
> /* Pre-compute ASID details */
> - num_asids = 1 << asid_bits;
> - asid_mask = num_asids - 1;
> + if (asid_bits) {
> + num_asids = 1 << asid_bits;
> + asid_mask = num_asids - 1;
> + }
>
> /*
> * Use ASID allocator only if number of HW ASIDs are
> @@ -255,7 +257,7 @@ static int __init asids_init(void)
> pr_info("ASID allocator using %lu bits (%lu entries)\n",
> asid_bits, num_asids);
> } else {
> - pr_info("ASID allocator disabled\n");
> + pr_info("ASID allocator disabled: %lu bits\n", asid_bits);
May be use:
pr_info("ASID allocator disabled (%lu bits)\n", asid_bits);
for consistency with the ASID enabled case.
Otherwise, it looks good to me.
Reviewed-by: Anup Patel <anup@brainfault.org>
> }
>
> return 0;
> --
> 2.30.2
>
>
> _______________________________________________
> linux-riscv mailing list
> linux-riscv@lists.infradead.org
> http://lists.infradead.org/mailman/listinfo/linux-riscv
Regards,
Anup
^ permalink raw reply [flat|nested] 4+ messages in thread
* [PATCH v2] riscv: mm: don't advertise 1 num_asid for 0 asid bits
2021-09-08 8:35 ` Anup Patel
@ 2021-09-08 17:30 ` Vineet Gupta
2021-10-03 17:10 ` Palmer Dabbelt
0 siblings, 1 reply; 4+ messages in thread
From: Vineet Gupta @ 2021-09-08 17:30 UTC (permalink / raw)
To: Paul Walmsley, Palmer Dabbelt, Albert Ou, Anup Patel,
Jisheng Zhang, Guo Ren, Kefeng Wang
Cc: linux-riscv, linux-kernel, Vineet Gupta, Anup Patel
Even if mmu doesn't support ASID, current code calculates @num_asids=1
which is misleading, so avoid setting any asid related variables in such
case.
Also while here, print the number of asid bits discovered even for the
disabled case.
Verified this on Hifive Unmatched.
Reviewed-by: Anup Patel <anup@brainfault.org>
Signed-off-by: Vineet Gupta <vgupta@kernel.org>
---
arch/riscv/mm/context.c | 8 +++++---
1 file changed, 5 insertions(+), 3 deletions(-)
diff --git a/arch/riscv/mm/context.c b/arch/riscv/mm/context.c
index ee3459cb6750..ea54cc0c9106 100644
--- a/arch/riscv/mm/context.c
+++ b/arch/riscv/mm/context.c
@@ -233,8 +233,10 @@ static int __init asids_init(void)
local_flush_tlb_all();
/* Pre-compute ASID details */
- num_asids = 1 << asid_bits;
- asid_mask = num_asids - 1;
+ if (asid_bits) {
+ num_asids = 1 << asid_bits;
+ asid_mask = num_asids - 1;
+ }
/*
* Use ASID allocator only if number of HW ASIDs are
@@ -255,7 +257,7 @@ static int __init asids_init(void)
pr_info("ASID allocator using %lu bits (%lu entries)\n",
asid_bits, num_asids);
} else {
- pr_info("ASID allocator disabled\n");
+ pr_info("ASID allocator disabled (%lu bits)\n", asid_bits);
}
return 0;
--
2.30.2
^ permalink raw reply related [flat|nested] 4+ messages in thread
* Re: [PATCH v2] riscv: mm: don't advertise 1 num_asid for 0 asid bits
2021-09-08 17:30 ` [PATCH v2] " Vineet Gupta
@ 2021-10-03 17:10 ` Palmer Dabbelt
0 siblings, 0 replies; 4+ messages in thread
From: Palmer Dabbelt @ 2021-10-03 17:10 UTC (permalink / raw)
To: vgupta
Cc: Paul Walmsley, aou, Anup Patel, jszhang, guoren, wangkefeng.wang,
linux-riscv, linux-kernel, vgupta, anup
On Wed, 08 Sep 2021 10:30:29 PDT (-0700), vgupta@kernel.org wrote:
> Even if mmu doesn't support ASID, current code calculates @num_asids=1
> which is misleading, so avoid setting any asid related variables in such
> case.
>
> Also while here, print the number of asid bits discovered even for the
> disabled case.
>
> Verified this on Hifive Unmatched.
>
> Reviewed-by: Anup Patel <anup@brainfault.org>
> Signed-off-by: Vineet Gupta <vgupta@kernel.org>
> ---
> arch/riscv/mm/context.c | 8 +++++---
> 1 file changed, 5 insertions(+), 3 deletions(-)
>
> diff --git a/arch/riscv/mm/context.c b/arch/riscv/mm/context.c
> index ee3459cb6750..ea54cc0c9106 100644
> --- a/arch/riscv/mm/context.c
> +++ b/arch/riscv/mm/context.c
> @@ -233,8 +233,10 @@ static int __init asids_init(void)
> local_flush_tlb_all();
>
> /* Pre-compute ASID details */
> - num_asids = 1 << asid_bits;
> - asid_mask = num_asids - 1;
> + if (asid_bits) {
> + num_asids = 1 << asid_bits;
> + asid_mask = num_asids - 1;
> + }
>
> /*
> * Use ASID allocator only if number of HW ASIDs are
> @@ -255,7 +257,7 @@ static int __init asids_init(void)
> pr_info("ASID allocator using %lu bits (%lu entries)\n",
> asid_bits, num_asids);
> } else {
> - pr_info("ASID allocator disabled\n");
> + pr_info("ASID allocator disabled (%lu bits)\n", asid_bits);
> }
>
> return 0;
Thanks, this is on for-next.
^ permalink raw reply [flat|nested] 4+ messages in thread
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