| Message ID | 20200205100719.24999-1-tomeu.vizoso@collabora.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | drm/panfrost: Don't try to map on error faults | expand |
Reviewed-by: Alyssa Rosenzweig <alyssa.rosenzweig@collabora.com> Although it might be nice to #define TRANSLATION_FAULT_LEVEL1 0xC1 ... #define TRANSLATION_FAULT_LEVEL4 0xC4 and then use semantic names instead of magic values. Minimally maybe add a comment explaining that. On Wed, Feb 05, 2020 at 11:07:16AM +0100, Tomeu Vizoso wrote: > If the exception type isn't one of the normal faults, 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> > --- > drivers/gpu/drm/panfrost/panfrost_mmu.c | 5 +++-- > 1 file changed, 3 insertions(+), 2 deletions(-) > > diff --git a/drivers/gpu/drm/panfrost/panfrost_mmu.c b/drivers/gpu/drm/panfrost/panfrost_mmu.c > index 763cfca886a7..80abddb4544c 100644 > --- a/drivers/gpu/drm/panfrost/panfrost_mmu.c > +++ b/drivers/gpu/drm/panfrost/panfrost_mmu.c > @@ -596,8 +596,9 @@ 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); > + if ((status & mask) == BIT(i) && > + exception_type >= 0xC1 && > + exception_type <= 0xC4) { > > ret = panfrost_mmu_map_fault_addr(pfdev, i, addr); > if (!ret) { > -- > 2.21.0 >
On 05/02/2020 10:07 am, Tomeu Vizoso wrote: > If the exception type isn't one of the normal faults, don't try to map > and instead go straight to a terminal fault. "One of the the normal faults" seems a rather vague way of saying "a translation fault", which is what we're specifically handling here, and logically the only fault reflecting something not yet mapped rather than mapped inappropriately ;) (Who knows how the level ended up as 1-4 rather than 0-3 as it really should be - another Mali Mystery(TM)...) > Otherwise, we can get flooded by kernel warnings and further faults. Either way, Reviewed-by: Robin Murphy <robin.murphy@arm.com> > Signed-off-by: Tomeu Vizoso <tomeu.vizoso@collabora.com> > --- > drivers/gpu/drm/panfrost/panfrost_mmu.c | 5 +++-- > 1 file changed, 3 insertions(+), 2 deletions(-) > > diff --git a/drivers/gpu/drm/panfrost/panfrost_mmu.c b/drivers/gpu/drm/panfrost/panfrost_mmu.c > index 763cfca886a7..80abddb4544c 100644 > --- a/drivers/gpu/drm/panfrost/panfrost_mmu.c > +++ b/drivers/gpu/drm/panfrost/panfrost_mmu.c > @@ -596,8 +596,9 @@ 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); > + if ((status & mask) == BIT(i) && > + exception_type >= 0xC1 && > + exception_type <= 0xC4) { > > ret = panfrost_mmu_map_fault_addr(pfdev, i, addr); > if (!ret) { >
On 05/02/2020 13:25, Robin Murphy wrote: > On 05/02/2020 10:07 am, Tomeu Vizoso wrote: >> If the exception type isn't one of the normal faults, don't try to map >> and instead go straight to a terminal fault. > > "One of the the normal faults" seems a rather vague way of saying "a > translation fault", which is what we're specifically handling here, and > logically the only fault reflecting something not yet mapped rather than > mapped inappropriately ;) > > (Who knows how the level ended up as 1-4 rather than 0-3 as it really > should be - another Mali Mystery(TM)...) Ah, but you're thinking of LPAE not Mali Magic Page Tables ('inspired by' LPAE but not actually compatible....) ;) However I do wonder what will happen when we enable aarch64 page tables in Bifrost. >> Otherwise, we can get flooded by kernel warnings and further faults. > > Either way, > > Reviewed-by: Robin Murphy <robin.murphy@arm.com> > >> Signed-off-by: Tomeu Vizoso <tomeu.vizoso@collabora.com> >> --- >> drivers/gpu/drm/panfrost/panfrost_mmu.c | 5 +++-- >> 1 file changed, 3 insertions(+), 2 deletions(-) >> >> diff --git a/drivers/gpu/drm/panfrost/panfrost_mmu.c >> b/drivers/gpu/drm/panfrost/panfrost_mmu.c >> index 763cfca886a7..80abddb4544c 100644 >> --- a/drivers/gpu/drm/panfrost/panfrost_mmu.c >> +++ b/drivers/gpu/drm/panfrost/panfrost_mmu.c >> @@ -596,8 +596,9 @@ 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); >> + if ((status & mask) == BIT(i) && >> + exception_type >= 0xC1 && >> + exception_type <= 0xC4) { I would suggest the best option here is to copy mali_kbase and check against a mask, in kbase[1] we have: switch (fault_status & AS_FAULTSTATUS_EXCEPTION_CODE_MASK) { case AS_FAULTSTATUS_EXCEPTION_CODE_TRANSLATION_FAULT: [1] https://gitlab.freedesktop.org/panfrost/linux-panfrost/blob/a864e6b9fbd093a033a90d5bbdd6dcc79a0667b2/mali_kbase_mmu.c#L108 Where: #define AS_FAULTSTATUS_EXCEPTION_CODE_MASK (0x7<<3) #define AS_FAULTSTATUS_EXCEPTION_CODE_TRANSLATION_FAULT (0x0<<3) Steve >> ret = panfrost_mmu_map_fault_addr(pfdev, i, addr); >> if (!ret) { >> > _______________________________________________ > dri-devel mailing list > dri-devel@lists.freedesktop.org > https://lists.freedesktop.org/mailman/listinfo/dri-devel
diff --git a/drivers/gpu/drm/panfrost/panfrost_mmu.c b/drivers/gpu/drm/panfrost/panfrost_mmu.c index 763cfca886a7..80abddb4544c 100644 --- a/drivers/gpu/drm/panfrost/panfrost_mmu.c +++ b/drivers/gpu/drm/panfrost/panfrost_mmu.c @@ -596,8 +596,9 @@ 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); + if ((status & mask) == BIT(i) && + exception_type >= 0xC1 && + exception_type <= 0xC4) { ret = panfrost_mmu_map_fault_addr(pfdev, i, addr); if (!ret) {
If the exception type isn't one of the normal faults, 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> --- drivers/gpu/drm/panfrost/panfrost_mmu.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-)