[PATCH 16/18] drm/etnaviv: handle MMU exception in IRQ handler

[Rob Clark]

On Mon, Aug 22, 2016 at 7:01 AM, Lucas Stach <l.stach at pengutronix.de> wrote:
> Bit 30 of the interrupt status signals an MMU exception. Handle this
> condition properly and dump some useful registers.
>
> Signed-off-by: Lucas Stach <l.stach at pengutronix.de>
> ---
>  drivers/gpu/drm/etnaviv/etnaviv_gpu.c  | 12 ++++++++++++
>  drivers/gpu/drm/etnaviv/state_hi.xml.h |  9 +++++----
>  2 files changed, 17 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/gpu/drm/etnaviv/etnaviv_gpu.c b/drivers/gpu/drm/etnaviv/etnaviv_gpu.c
> index 4c706438c7c8..923f6c78e1af 100644
> --- a/drivers/gpu/drm/etnaviv/etnaviv_gpu.c
> +++ b/drivers/gpu/drm/etnaviv/etnaviv_gpu.c
> @@ -1402,6 +1402,18 @@ static irqreturn_t irq_handler(int irq, void *data)
>                         intr &= ~VIVS_HI_INTR_ACKNOWLEDGE_AXI_BUS_ERROR;
>                 }
>
> +               if (intr & VIVS_HI_INTR_ACKNOWLEDGE_MMU_EXCEPTION) {
> +                       int i;
> +
> +                       dev_err(gpu->dev, "MMU fault status 0x%08x\n",
> +                               gpu_read(gpu, VIVS_MMUv2_STATUS));

Drive-by comment, and I don't know if this is the case w/ vivante, but
on adreno I have observed that when I get iommu faults (for example,
bad texture state or something like that) I tend to get a *lot* of
iommu faults, not just one.

If that is the case here, you might want to ratelimit the dev_err prints..

BR,
-R

> +                       for (i = 0; i < 4; i++)
> +                               dev_err(gpu->dev, "MMU %d fault addr 0x%08x\n",
> +                                       i, gpu_read(gpu,
> +                                       VIVS_MMUv2_EXCEPTION_ADDR(i)));
> +                       intr &= ~VIVS_HI_INTR_ACKNOWLEDGE_MMU_EXCEPTION;
> +               }
> +
>                 while ((event = ffs(intr)) != 0) {
>                         struct fence *fence;
>
> diff --git a/drivers/gpu/drm/etnaviv/state_hi.xml.h b/drivers/gpu/drm/etnaviv/state_hi.xml.h
> index 807a3d9e0dd5..43c73e2ed34f 100644
> --- a/drivers/gpu/drm/etnaviv/state_hi.xml.h
> +++ b/drivers/gpu/drm/etnaviv/state_hi.xml.h
> @@ -8,10 +8,10 @@ http://0x04.net/cgit/index.cgi/rules-ng-ng
>  git clone git://0x04.net/rules-ng-ng
>
>  The rules-ng-ng source files this header was generated from are:
> -- state_hi.xml (  24309 bytes, from 2015-12-12 09:02:53)
> -- common.xml   (  18437 bytes, from 2015-12-12 09:02:53)
> +- state_hi.xml (  25620 bytes, from 2016-08-19 22:07:37)
> +- common.xml   (  20583 bytes, from 2016-06-07 05:22:38)
>
> -Copyright (C) 2015
> +Copyright (C) 2016
>  */
>
>
> @@ -78,9 +78,10 @@ Copyright (C) 2015
>  #define VIVS_HI_AXI_STATUS_DET_RD_ERR                          0x00000200
>
>  #define VIVS_HI_INTR_ACKNOWLEDGE                               0x00000010
> -#define VIVS_HI_INTR_ACKNOWLEDGE_INTR_VEC__MASK                        0x7fffffff
> +#define VIVS_HI_INTR_ACKNOWLEDGE_INTR_VEC__MASK                        0x3fffffff
>  #define VIVS_HI_INTR_ACKNOWLEDGE_INTR_VEC__SHIFT               0
>  #define VIVS_HI_INTR_ACKNOWLEDGE_INTR_VEC(x)                   (((x) << VIVS_HI_INTR_ACKNOWLEDGE_INTR_VEC__SHIFT) & VIVS_HI_INTR_ACKNOWLEDGE_INTR_VEC__MASK)
> +#define VIVS_HI_INTR_ACKNOWLEDGE_MMU_EXCEPTION                 0x40000000
>  #define VIVS_HI_INTR_ACKNOWLEDGE_AXI_BUS_ERROR                 0x80000000
>
>  #define VIVS_HI_INTR_ENBL                                      0x00000014
> --
> 2.8.1
>
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