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Commit 4cb9bcb3 authored by Mitchel Humpherys's avatar Mitchel Humpherys Committed by Matt Wagantall
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iommu/arm-smmu: add DT option to make address size faults fatal 



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: default avatarMitchel Humpherys <mitchelh@codeaurora.org>
parent f093ea87

Documentation/devicetree/bindings/iommu/arm,smmu.txt

+6 −0
Original line number Diff line number Diff line
@@ -73,6 +73,12 @@ 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

drivers/iommu/arm-smmu.c

+9 −0
Original line number Diff line number Diff line
@@ -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;