[PATCH 0/1] versal-ospi fix

[PATCH 0/1] versal-ospi fix

[Sai Pavan Boddu]

Disable reentrancy on iomem_dac memory-region.

Sai Pavan Boddu (1):
  xlnx-versal-ospi: disable reentrancy detection for iomem_dac

 hw/ssi/xlnx-versal-ospi.c | 1 +
 1 file changed, 1 insertion(+)

-- 
2.25.1

[PATCH 1/1] xlnx-versal-ospi: disable reentrancy detection for iomem_dac

[Sai Pavan Boddu]

The OSPI DMA reads flash data through the OSPI linear address space (the
iomem_dac region), because of this the reentrancy guard introduced in
commit a2e1753b ("memory: prevent dma-reentracy issues") is disabled for
the memory region.

Signed-off-by: Sai Pavan Boddu <sai.pavan.boddu@amd.com>
---
 hw/ssi/xlnx-versal-ospi.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/hw/ssi/xlnx-versal-ospi.c b/hw/ssi/xlnx-versal-ospi.c
index 1a61679c2f..5123e7dde7 100644
--- a/hw/ssi/xlnx-versal-ospi.c
+++ b/hw/ssi/xlnx-versal-ospi.c
@@ -1772,6 +1772,7 @@ static void xlnx_versal_ospi_init(Object *obj)
     memory_region_init_io(&s->iomem_dac, obj, &ospi_dac_ops, s,
                           TYPE_XILINX_VERSAL_OSPI "-dac", 0x20000000);
     sysbus_init_mmio(sbd, &s->iomem_dac);
+    s->iomem_dac.disable_reentrancy_guard = true;
 
     sysbus_init_irq(sbd, &s->irq);
 
-- 
2.25.1

[PATCH 1/1] xlnx-versal-ospi: disable reentrancy detection for iomem_dac

[Sai Pavan Boddu]

The OSPI DMA reads flash data through the OSPI linear address space (the
iomem_dac region), because of this the reentrancy guard introduced in
commit a2e1753b ("memory: prevent dma-reentracy issues") is disabled for
the memory region.

Signed-off-by: Sai Pavan Boddu <sai.pavan.boddu@amd.com>
---
 hw/ssi/xlnx-versal-ospi.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/hw/ssi/xlnx-versal-ospi.c b/hw/ssi/xlnx-versal-ospi.c
index 1a61679c2f..5123e7dde7 100644
--- a/hw/ssi/xlnx-versal-ospi.c
+++ b/hw/ssi/xlnx-versal-ospi.c
@@ -1772,6 +1772,7 @@ static void xlnx_versal_ospi_init(Object *obj)
     memory_region_init_io(&s->iomem_dac, obj, &ospi_dac_ops, s,
                           TYPE_XILINX_VERSAL_OSPI "-dac", 0x20000000);
     sysbus_init_mmio(sbd, &s->iomem_dac);
+    s->iomem_dac.disable_reentrancy_guard = true;
 
     sysbus_init_irq(sbd, &s->irq);
 
-- 
2.25.1

Re: [PATCH 1/1] xlnx-versal-ospi: disable reentrancy detection for iomem_dac

[Francisco Iglesias]

On [2023 Dec 05] Tue 15:18:02, Sai Pavan Boddu wrote:
> The OSPI DMA reads flash data through the OSPI linear address space (the
> iomem_dac region), because of this the reentrancy guard introduced in
> commit a2e1753b ("memory: prevent dma-reentracy issues") is disabled for
> the memory region.
> 
> Signed-off-by: Sai Pavan Boddu <sai.pavan.boddu@amd.com>

Reviewed-by: Francisco Iglesias <frasse.iglesias@gmail.com>
Tested-by: Francisco Iglesias <frasse.iglesias@gmail.com>


> ---
>  hw/ssi/xlnx-versal-ospi.c | 1 +
>  1 file changed, 1 insertion(+)
> 
> diff --git a/hw/ssi/xlnx-versal-ospi.c b/hw/ssi/xlnx-versal-ospi.c
> index 1a61679c2f..5123e7dde7 100644
> --- a/hw/ssi/xlnx-versal-ospi.c
> +++ b/hw/ssi/xlnx-versal-ospi.c
> @@ -1772,6 +1772,7 @@ static void xlnx_versal_ospi_init(Object *obj)
>      memory_region_init_io(&s->iomem_dac, obj, &ospi_dac_ops, s,
>                            TYPE_XILINX_VERSAL_OSPI "-dac", 0x20000000);
>      sysbus_init_mmio(sbd, &s->iomem_dac);
> +    s->iomem_dac.disable_reentrancy_guard = true;
>  
>      sysbus_init_irq(sbd, &s->irq);
>  
> -- 
> 2.25.1
> 
> 

Re: [PATCH 1/1] xlnx-versal-ospi: disable reentrancy detection for iomem_dac

[Peter Maydell]

On Tue, 5 Dec 2023 at 10:08, Sai Pavan Boddu <sai.pavan.boddu@amd.com> wrote:
>
> The OSPI DMA reads flash data through the OSPI linear address space (the
> iomem_dac region), because of this the reentrancy guard introduced in
> commit a2e1753b ("memory: prevent dma-reentracy issues") is disabled for
> the memory region.
>
> Signed-off-by: Sai Pavan Boddu <sai.pavan.boddu@amd.com>
> ---
>  hw/ssi/xlnx-versal-ospi.c | 1 +
>  1 file changed, 1 insertion(+)
>
> diff --git a/hw/ssi/xlnx-versal-ospi.c b/hw/ssi/xlnx-versal-ospi.c
> index 1a61679c2f..5123e7dde7 100644
> --- a/hw/ssi/xlnx-versal-ospi.c
> +++ b/hw/ssi/xlnx-versal-ospi.c
> @@ -1772,6 +1772,7 @@ static void xlnx_versal_ospi_init(Object *obj)
>      memory_region_init_io(&s->iomem_dac, obj, &ospi_dac_ops, s,
>                            TYPE_XILINX_VERSAL_OSPI "-dac", 0x20000000);
>      sysbus_init_mmio(sbd, &s->iomem_dac);
> +    s->iomem_dac.disable_reentrancy_guard = true;

Where we set this flag we should have a comment explaining why
we need to do it, please.

PS: for a single patch you don't need to use a separate cover letter;
cover letters are only needed for multi-patch series.

thanks
-- PMM

RE: [PATCH 1/1] xlnx-versal-ospi: disable reentrancy detection for iomem_dac

[Boddu, Sai Pavan]

Hi Peter,

>-----Original Message-----
>From: Peter Maydell <peter.maydell@linaro.org>
>Sent: Tuesday, December 12, 2023 10:12 PM
>To: Boddu, Sai Pavan <sai.pavan.boddu@amd.com>
>Cc: qemu-devel@nongnu.org; qemu-arm@nongnu.org; qemu-
>block@nongnu.org; Alistair Francis <alistair@alistair23.me>; Edgar E. Iglesias
><edgar.iglesias@gmail.com>; Kevin Wolf <kwolf@redhat.com>; Francisco
>Iglesias <frasse.iglesias@gmail.com>; saipavanboddu@gmail.com
>Subject: Re: [PATCH 1/1] xlnx-versal-ospi: disable reentrancy detection for
>iomem_dac
>
>On Tue, 5 Dec 2023 at 10:08, Sai Pavan Boddu <sai.pavan.boddu@amd.com>
>wrote:
>>
>> The OSPI DMA reads flash data through the OSPI linear address space
>> (the iomem_dac region), because of this the reentrancy guard
>> introduced in commit a2e1753b ("memory: prevent dma-reentracy issues")
>> is disabled for the memory region.
>>
>> Signed-off-by: Sai Pavan Boddu <sai.pavan.boddu@amd.com>
>> ---
>>  hw/ssi/xlnx-versal-ospi.c | 1 +
>>  1 file changed, 1 insertion(+)
>>
>> diff --git a/hw/ssi/xlnx-versal-ospi.c b/hw/ssi/xlnx-versal-ospi.c
>> index 1a61679c2f..5123e7dde7 100644
>> --- a/hw/ssi/xlnx-versal-ospi.c
>> +++ b/hw/ssi/xlnx-versal-ospi.c
>> @@ -1772,6 +1772,7 @@ static void xlnx_versal_ospi_init(Object *obj)
>>      memory_region_init_io(&s->iomem_dac, obj, &ospi_dac_ops, s,
>>                            TYPE_XILINX_VERSAL_OSPI "-dac", 0x20000000);
>>      sysbus_init_mmio(sbd, &s->iomem_dac);
>> +    s->iomem_dac.disable_reentrancy_guard = true;
>
>Where we set this flag we should have a comment explaining why we need to
>do it, please.
[Boddu, Sai Pavan] Sure, I will send a V2 on this.

Regards,
Sai pavan
>
>PS: for a single patch you don't need to use a separate cover letter; cover letters
>are only needed for multi-patch series.
>
>thanks
>-- PMM