| Message ID | 1482179918-4457-1-git-send-email-nwatters@codeaurora.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
Hi Nate, Thanks for the patch. On Mon, Dec 19, 2016 at 03:38:38PM -0500, Nate Watterson wrote: > To ensure that the stage-1 context ptr for an ste points to the > intended context descriptor, this patch adds code to clear away > the stale context ptr value prior to or'ing in the new one. > > Signed-off-by: Nate Watterson <nwatters@codeaurora.org> > --- > drivers/iommu/arm-smmu-v3.c | 2 ++ > 1 file changed, 2 insertions(+) > > diff --git a/drivers/iommu/arm-smmu-v3.c b/drivers/iommu/arm-smmu-v3.c > index 4d6ec44..093f9f1 100644 > --- a/drivers/iommu/arm-smmu-v3.c > +++ b/drivers/iommu/arm-smmu-v3.c > @@ -1080,6 +1080,8 @@ static void arm_smmu_write_strtab_ent(struct arm_smmu_device *smmu, u32 sid, > if (smmu->features & ARM_SMMU_FEAT_STALLS) > dst[1] |= cpu_to_le64(STRTAB_STE_1_S1STALLD); > > + val &= ~(STRTAB_STE_0_S1CTXPTR_MASK << > + STRTAB_STE_0_S1CTXPTR_SHIFT); > val |= (ste->s1_cfg->cdptr_dma & STRTAB_STE_0_S1CTXPTR_MASK > << STRTAB_STE_0_S1CTXPTR_SHIFT) | > STRTAB_STE_0_CFG_S1_TRANS; Good catch. We only clear the Config field at present, although I think it would be better if we just did val = 0 instead of clearing the Config field, and then just recreate all of the S1-related fields (ctxptr, fmt, cdmax) if we're installing a stage-1 STE. The other STE fields aren't treated as read-modify-write, so it's more consistent not to treat the initial dword specially other than for determining ste_live. What do you think? Will
diff --git a/drivers/iommu/arm-smmu-v3.c b/drivers/iommu/arm-smmu-v3.c index 4d6ec44..093f9f1 100644 --- a/drivers/iommu/arm-smmu-v3.c +++ b/drivers/iommu/arm-smmu-v3.c @@ -1080,6 +1080,8 @@ static void arm_smmu_write_strtab_ent(struct arm_smmu_device *smmu, u32 sid, if (smmu->features & ARM_SMMU_FEAT_STALLS) dst[1] |= cpu_to_le64(STRTAB_STE_1_S1STALLD); + val &= ~(STRTAB_STE_0_S1CTXPTR_MASK << + STRTAB_STE_0_S1CTXPTR_SHIFT); val |= (ste->s1_cfg->cdptr_dma & STRTAB_STE_0_S1CTXPTR_MASK << STRTAB_STE_0_S1CTXPTR_SHIFT) | STRTAB_STE_0_CFG_S1_TRANS;
To ensure that the stage-1 context ptr for an ste points to the intended context descriptor, this patch adds code to clear away the stale context ptr value prior to or'ing in the new one. Signed-off-by: Nate Watterson <nwatters@codeaurora.org> --- drivers/iommu/arm-smmu-v3.c | 2 ++ 1 file changed, 2 insertions(+)