On Thu, Aug 22, 2024 at 04:15:24PM -0700, Rob Clark wrote:
> On Thu, Aug 22, 2024 at 1:34 PM Akhil P Oommen <quic_akhilpo@xxxxxxxxxxx> wrote:
> >
> > On Tue, Aug 20, 2024 at 10:16:47AM -0700, Rob Clark wrote: > From: Rob Clark <robdclark@xxxxxxxxxxxx>
> > >
> > > In the case of iova fault triggered devcore dumps, include additional
> > > debug information based on what we think is the current page tables,
> > > including the TTBR0 value (which should match what we have in
> > > adreno_smmu_fault_info unless things have gone horribly wrong), and
> > > the pagetable entries traversed in the process of resolving the
> > > faulting iova.
> > >
> > > Signed-off-by: Rob Clark <robdclark@xxxxxxxxxxxx>
> > > ---
> > > drivers/gpu/drm/msm/adreno/adreno_gpu.c | 10 ++++++++++
> > > drivers/gpu/drm/msm/msm_gpu.c | 9 +++++++++
> > > drivers/gpu/drm/msm/msm_gpu.h | 8 ++++++++
> > > drivers/gpu/drm/msm/msm_iommu.c | 22 ++++++++++++++++++++++
> > > drivers/gpu/drm/msm/msm_mmu.h | 3 ++-
> > > 5 files changed, 51 insertions(+), 1 deletion(-)
> > >
> > > diff --git a/drivers/gpu/drm/msm/adreno/adreno_gpu.c b/drivers/gpu/drm/msm/adreno/adreno_gpu.c
> > > index 1c6626747b98..3848b5a64351 100644
> > > --- a/drivers/gpu/drm/msm/adreno/adreno_gpu.c
> > > +++ b/drivers/gpu/drm/msm/adreno/adreno_gpu.c
> > > @@ -864,6 +864,16 @@ void adreno_show(struct msm_gpu *gpu, struct msm_gpu_state *state,
> > > drm_printf(p, " - dir=%s\n", info->flags & IOMMU_FAULT_WRITE ? "WRITE" : "READ");
> > > drm_printf(p, " - type=%s\n", info->type);
> > > drm_printf(p, " - source=%s\n", info->block);
> > > +
> > > + /* Information extracted from what we think are the current
> > > + * pgtables. Hopefully the TTBR0 matches what we've extracted
> > > + * from the SMMU registers in smmu_info!
> > > + */
> > > + drm_puts(p, "pgtable-fault-info:\n");
> > > + drm_printf(p, " - ttbr0: %.16llx\n", (u64)info->pgtbl_ttbr0);
> >
> > "0x" prefix? Otherwise, it is a bit confusing when the below one is
> > decimal.
>
> mixed feelings, the extra 0x is annoying when pasting into calc which
> is a simple way to get binary decoding
>
> OTOH none of this is machine decoded so I guess we could change it
On second thought, I think it is fine as this is an address. Probably,
it is helpful for the pte values below.
>
> > > + drm_printf(p, " - asid: %d\n", info->asid);
> > > + drm_printf(p, " - ptes: %.16llx %.16llx %.16llx %.16llx\n",
> > > + info->ptes[0], info->ptes[1], info->ptes[2], info->ptes[3]);
> >
> > Does crashdec decodes this?
>
> No, it just passed thru for human eyeballs
>
> crashdec _does_ have some logic to flag buffers that are "near" the
> faulting iova to help identify if the fault is an underflow/overflow
> (which has been, along with the pte trail, useful to debug some
> issues)
Alright.
Reviewed-by: Akhil P Oommen <quic_akhilpo@xxxxxxxxxxx>
-Akhil.
>
> BR,
> -R
>
> > -Akhil.
> >
> > > }
> > >
> > > drm_printf(p, "rbbm-status: 0x%08x\n", state->rbbm_status);
> > > diff --git a/drivers/gpu/drm/msm/msm_gpu.c b/drivers/gpu/drm/msm/msm_gpu.c
> > > index 3666b42b4ecd..bf2f8b2a7ccc 100644
> > > --- a/drivers/gpu/drm/msm/msm_gpu.c
> > > +++ b/drivers/gpu/drm/msm/msm_gpu.c
> > > @@ -281,6 +281,15 @@ static void msm_gpu_crashstate_capture(struct msm_gpu *gpu,
> > > if (submit) {
> > > int i;
> > >
> > > + if (state->fault_info.ttbr0) {
> > > + struct msm_gpu_fault_info *info = &state->fault_info;
> > > + struct msm_mmu *mmu = submit->aspace->mmu;
> > > +
> > > + msm_iommu_pagetable_params(mmu, &info->pgtbl_ttbr0,
> > > + &info->asid);
> > > + msm_iommu_pagetable_walk(mmu, info->iova, info->ptes);
> > > + }
> > > +
> > > state->bos = kcalloc(submit->nr_bos,
> > > sizeof(struct msm_gpu_state_bo), GFP_KERNEL);
> > >
> > > diff --git a/drivers/gpu/drm/msm/msm_gpu.h b/drivers/gpu/drm/msm/msm_gpu.h
> > > index 1f02bb9956be..82e838ba8c80 100644
> > > --- a/drivers/gpu/drm/msm/msm_gpu.h
> > > +++ b/drivers/gpu/drm/msm/msm_gpu.h
> > > @@ -101,6 +101,14 @@ struct msm_gpu_fault_info {
> > > int flags;
> > > const char *type;
> > > const char *block;
> > > +
> > > + /* Information about what we think/expect is the current SMMU state,
> > > + * for example expected_ttbr0 should match smmu_info.ttbr0 which
> > > + * was read back from SMMU registers.
> > > + */
> > > + phys_addr_t pgtbl_ttbr0;
> > > + u64 ptes[4];
> > > + int asid;
> > > };
> > >
> > > /**
> > > diff --git a/drivers/gpu/drm/msm/msm_iommu.c b/drivers/gpu/drm/msm/msm_iommu.c
> > > index 2a94e82316f9..3e692818ba1f 100644
> > > --- a/drivers/gpu/drm/msm/msm_iommu.c
> > > +++ b/drivers/gpu/drm/msm/msm_iommu.c
> > > @@ -195,6 +195,28 @@ struct iommu_domain_geometry *msm_iommu_get_geometry(struct msm_mmu *mmu)
> > > return &iommu->domain->geometry;
> > > }
> > >
> > > +int
> > > +msm_iommu_pagetable_walk(struct msm_mmu *mmu, unsigned long iova, uint64_t ptes[4])
> > > +{
> > > + struct msm_iommu_pagetable *pagetable;
> > > + struct arm_lpae_io_pgtable_walk_data wd = {};
> > > +
> > > + if (mmu->type != MSM_MMU_IOMMU_PAGETABLE)
> > > + return -EINVAL;
> > > +
> > > + pagetable = to_pagetable(mmu);
> > > +
> > > + if (!pagetable->pgtbl_ops->pgtable_walk)
> > > + return -EINVAL;
> > > +
> > > + pagetable->pgtbl_ops->pgtable_walk(pagetable->pgtbl_ops, iova, &wd);
> > > +
> > > + for (int i = 0; i < ARRAY_SIZE(wd.ptes); i++)
> > > + ptes[i] = wd.ptes[i];
> > > +
> > > + return 0;
> > > +}
> > > +
> > > static const struct msm_mmu_funcs pagetable_funcs = {
> > > .map = msm_iommu_pagetable_map,
> > > .unmap = msm_iommu_pagetable_unmap,
> > > diff --git a/drivers/gpu/drm/msm/msm_mmu.h b/drivers/gpu/drm/msm/msm_mmu.h
> > > index 88af4f490881..96e509bd96a6 100644
> > > --- a/drivers/gpu/drm/msm/msm_mmu.h
> > > +++ b/drivers/gpu/drm/msm/msm_mmu.h
> > > @@ -53,7 +53,8 @@ static inline void msm_mmu_set_fault_handler(struct msm_mmu *mmu, void *arg,
> > > struct msm_mmu *msm_iommu_pagetable_create(struct msm_mmu *parent);
> > >
> > > int msm_iommu_pagetable_params(struct msm_mmu *mmu, phys_addr_t *ttbr,
> > > - int *asid);
> > > + int *asid);
> > > +int msm_iommu_pagetable_walk(struct msm_mmu *mmu, unsigned long iova, uint64_t ptes[4]);
> > > struct iommu_domain_geometry *msm_iommu_get_geometry(struct msm_mmu *mmu);
> > >
> > > #endif /* __MSM_MMU_H__ */
> > > --
> > > 2.46.0
> > >
