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iommu/arm-smmu: add DT option to make address size faults fatal

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Some hardware requires special fixups to recover from address size
faults.  Rather than applying the fixups add an option to just BUG since
address size faults are due to a fundamental programming error from
which we don't care about recovering anyways.

Change-Id: Ibb70e4ec00683562dae9f3239b286daa5deabd45
Signed-off-by: Mitchel Humpherys <mitchelh@codeaurora.org>
This commit is contained in:
Mitchel Humpherys 2015-01-30 14:58:52 -08:00 • committed by David Keitel
parent cde5a4ec7b
commit a0f2281e2b
2 changed files with 15 additions and 0 deletions
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6
Documentation/devicetree/bindings/iommu/arm,smmu.txt
View file

@ -79,6 +79,12 @@ conditions.
- qcom,errata-ctx-fault-hang : Enable workaround for a context fault hang
hardware errata.
- qcom,fatal-asf : Enable BUG_ON for address size faults. Some hardware
requires special fixups to recover from address size
faults. Rather than applying the fixups just BUG since
address size faults are due to a fundamental programming
error from which we don't care about recovering anyways.
- clocks : List of clocks to be used during SMMU register access. See
Documentation/devicetree/bindings/clock/clock-bindings.txt
for information about the format. For each clock specified

9
drivers/iommu/arm-smmu.c
View file

@ -428,6 +428,7 @@ struct arm_smmu_device {
#define ARM_SMMU_OPT_REGISTER_SAVE (1 << 3)
#define ARM_SMMU_OPT_SKIP_INIT (1 << 4)
#define ARM_SMMU_OPT_ERRATA_CTX_FAULT_HANG (1 << 5)
#define ARM_SMMU_OPT_FATAL_ASF (1 << 6)
u32 options;
enum arm_smmu_arch_version version;
@ -498,6 +499,7 @@ static struct arm_smmu_option_prop arm_smmu_options[] = {
{ ARM_SMMU_OPT_REGISTER_SAVE, "qcom,register-save" },
{ ARM_SMMU_OPT_SKIP_INIT, "qcom,skip-init" },
{ ARM_SMMU_OPT_ERRATA_CTX_FAULT_HANG, "qcom,errata-ctx-fault-hang" },
{ ARM_SMMU_OPT_FATAL_ASF, "qcom,fatal-asf" },
{ 0, NULL},
};
@ -839,6 +841,7 @@ static irqreturn_t arm_smmu_context_fault(int irq, void *dev)
void __iomem *cb_base;
bool ctx_hang_errata =
smmu->options & ARM_SMMU_OPT_ERRATA_CTX_FAULT_HANG;
bool fatal_asf = smmu->options & ARM_SMMU_OPT_FATAL_ASF;
arm_smmu_enable_clocks(smmu);
@ -855,6 +858,12 @@ static irqreturn_t arm_smmu_context_fault(int irq, void *dev)
"Unexpected context fault (fsr 0x%x)\n",
fsr);
if (fatal_asf && (fsr & FSR_ASF)) {
dev_err(smmu->dev,
"Took an address size fault. Refusing to recover.\n");
BUG();
}
fsynr = readl_relaxed(cb_base + ARM_SMMU_CB_FSYNR0);
flags = fsynr & FSYNR0_WNR ? IOMMU_FAULT_WRITE : IOMMU_FAULT_READ;