lkml.org 
[lkml]   [2020]   [Feb]   [13]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
SubjectRe: [PATCH v2] drm/panfrost: Don't try to map on error faults
From
Date
On 12/02/2020 20:22, Rob Herring wrote:
> From: Tomeu Vizoso <tomeu.vizoso@collabora.com>
>
> If the exception type isn't a translation fault, don't try to map and
> instead go straight to a terminal fault.
>
> Otherwise, we can get flooded by kernel warnings and further faults.
>
> Signed-off-by: Tomeu Vizoso <tomeu.vizoso@collabora.com>
> Signed-off-by: Rob Herring <robh@kernel.org>
> ---
> I rewrote this some simplifying the code and somewhat following Steven's
> suggested. Still not using defines though. No defines here was good
> enough before IMO.

Heresy! It's a good thing you're not writing kbase code - there you
(seemingly) need to pick a #define which is as long as possible, but
then still wrap the code to avoid the 80 character limit... For
example[1]. Although shifting the code right might get you extra bonus
points, deep nesting seems to be encouraged! ;)

[1]
https://gitlab.freedesktop.org/panfrost/mali_kbase/blob/master/driver/product/kernel/drivers/gpu/arm/midgard/backend/gpu/mali_kbase_js_backend.c#L156

>
> Only compile tested.

I've done some quick testing on a Firefly RK3288. But I don't have any
(handy) tests to trigger non-TRANSLATION_FAULT MMU faults.

Reviewed-by: Steven Price <steven.price@arm.com>

Thanks,

Steve

>
> drivers/gpu/drm/panfrost/panfrost_mmu.c | 44 +++++++++++--------------
> 1 file changed, 19 insertions(+), 25 deletions(-)
>
> diff --git a/drivers/gpu/drm/panfrost/panfrost_mmu.c b/drivers/gpu/drm/panfrost/panfrost_mmu.c
> index 763cfca886a7..4f2836bd9215 100644
> --- a/drivers/gpu/drm/panfrost/panfrost_mmu.c
> +++ b/drivers/gpu/drm/panfrost/panfrost_mmu.c
> @@ -596,33 +596,27 @@ static irqreturn_t panfrost_mmu_irq_handler_thread(int irq, void *data)
> source_id = (fault_status >> 16);
>
> /* Page fault only */
> - if ((status & mask) == BIT(i)) {
> - WARN_ON(exception_type < 0xC1 || exception_type > 0xC4);
> -
> + ret = -1;
> + if ((status & mask) == BIT(i) && (exception_type & 0xF8) == 0xC0)
> ret = panfrost_mmu_map_fault_addr(pfdev, i, addr);
> - if (!ret) {
> - mmu_write(pfdev, MMU_INT_CLEAR, BIT(i));
> - status &= ~mask;
> - continue;
> - }
> - }
>
> - /* terminal fault, print info about the fault */
> - dev_err(pfdev->dev,
> - "Unhandled Page fault in AS%d at VA 0x%016llX\n"
> - "Reason: %s\n"
> - "raw fault status: 0x%X\n"
> - "decoded fault status: %s\n"
> - "exception type 0x%X: %s\n"
> - "access type 0x%X: %s\n"
> - "source id 0x%X\n",
> - i, addr,
> - "TODO",
> - fault_status,
> - (fault_status & (1 << 10) ? "DECODER FAULT" : "SLAVE FAULT"),
> - exception_type, panfrost_exception_name(pfdev, exception_type),
> - access_type, access_type_name(pfdev, fault_status),
> - source_id);
> + if (ret)
> + /* terminal fault, print info about the fault */
> + dev_err(pfdev->dev,
> + "Unhandled Page fault in AS%d at VA 0x%016llX\n"
> + "Reason: %s\n"
> + "raw fault status: 0x%X\n"
> + "decoded fault status: %s\n"
> + "exception type 0x%X: %s\n"
> + "access type 0x%X: %s\n"
> + "source id 0x%X\n",
> + i, addr,
> + "TODO",
> + fault_status,
> + (fault_status & (1 << 10) ? "DECODER FAULT" : "SLAVE FAULT"),
> + exception_type, panfrost_exception_name(pfdev, exception_type),
> + access_type, access_type_name(pfdev, fault_status),
> + source_id);
>
> mmu_write(pfdev, MMU_INT_CLEAR, mask);
>
>

\
 
 \ /
  Last update: 2020-02-13 12:15    [W:0.031 / U:19.372 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site