Re: [Qemu-devel] [PATCH v1 24/30] RISC-V: Fix PLIC pending bitfield reads

[Alistair Francis]

On Tue, May 22, 2018 at 5:15 PM, Michael Clark  wrote:
> The address calculation for the pending bitfield had
> a copy paste bug. This bug went unnoticed because the Linux
> PLIC driver does not read the pending bitfield, rather it
> reads pending interrupt numbers from the claim register
> and writes acknowledgements back to the claim register.
>
> Cc: Palmer Dabbelt 
> Cc: Sagar Karandikar 
> Cc: Bastian Koppelmann 
> Cc: Alistair Francis 
> Reported-by: Vincent Siles 
> Signed-off-by: Michael Clark 

Reviewed-by: Alistair Francis 

Alistair

> ---
>  hw/riscv/sifive_plic.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/hw/riscv/sifive_plic.c b/hw/riscv/sifive_plic.c
> index 28e28d932f7c..b81d29faff99 100644
> --- a/hw/riscv/sifive_plic.c
> +++ b/hw/riscv/sifive_plic.c
> @@ -215,7 +215,7 @@ static uint64_t sifive_plic_read(void *opaque, hwaddr 
> addr, unsigned size)
>  } else if (addr >= plic->pending_base && /* 1 bit per source */
> addr < plic->pending_base + (plic->num_sources >> 3))
>  {
> -uint32_t word = (addr - plic->priority_base) >> 2;
> +uint32_t word = (addr - plic->pending_base) >> 2;
>  if (RISCV_DEBUG_PLIC) {
>  qemu_log("plic: read pending: word=%d value=%d\n",
>  word, plic->pending[word]);
> --
> 2.7.0
>
>

[Qemu-devel] [PATCH v1 24/30] RISC-V: Fix PLIC pending bitfield reads

[Michael Clark]

The address calculation for the pending bitfield had
a copy paste bug. This bug went unnoticed because the Linux
PLIC driver does not read the pending bitfield, rather it
reads pending interrupt numbers from the claim register
and writes acknowledgements back to the claim register.

Cc: Palmer Dabbelt 
Cc: Sagar Karandikar 
Cc: Bastian Koppelmann 
Cc: Alistair Francis 
Reported-by: Vincent Siles 
Signed-off-by: Michael Clark 
---
 hw/riscv/sifive_plic.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/hw/riscv/sifive_plic.c b/hw/riscv/sifive_plic.c
index 28e28d932f7c..b81d29faff99 100644
--- a/hw/riscv/sifive_plic.c
+++ b/hw/riscv/sifive_plic.c
@@ -215,7 +215,7 @@ static uint64_t sifive_plic_read(void *opaque, hwaddr addr, 
unsigned size)
 } else if (addr >= plic->pending_base && /* 1 bit per source */
addr < plic->pending_base + (plic->num_sources >> 3))
 {
-uint32_t word = (addr - plic->priority_base) >> 2;
+uint32_t word = (addr - plic->pending_base) >> 2;
 if (RISCV_DEBUG_PLIC) {
 qemu_log("plic: read pending: word=%d value=%d\n",
 word, plic->pending[word]);
-- 
2.7.0