Re: [RESEND PATCH v4 1/6] iommu/arm-smmu: Add support for driver IOMMU fault handlers

[Will Deacon <will@kernel.org>]

On Wed, Jun 02, 2021 at 09:52:44AM -0700, Rob Clark wrote:
> From: Jordan Crouse <jcrouse@codeaurora.org>
> 
> Call report_iommu_fault() to allow upper-level drivers to register their
> own fault handlers.
> 
> Signed-off-by: Jordan Crouse <jcrouse@codeaurora.org>
> Signed-off-by: Rob Clark <robdclark@chromium.org>
> ---
>  drivers/iommu/arm/arm-smmu/arm-smmu.c | 9 +++++++--
>  1 file changed, 7 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/iommu/arm/arm-smmu/arm-smmu.c b/drivers/iommu/arm/arm-smmu/arm-smmu.c
> index 6f72c4d208ca..b4b32d31fc06 100644
> --- a/drivers/iommu/arm/arm-smmu/arm-smmu.c
> +++ b/drivers/iommu/arm/arm-smmu/arm-smmu.c
> @@ -408,6 +408,7 @@ static irqreturn_t arm_smmu_context_fault(int irq, void *dev)
>  	struct arm_smmu_domain *smmu_domain = to_smmu_domain(domain);
>  	struct arm_smmu_device *smmu = smmu_domain->smmu;
>  	int idx = smmu_domain->cfg.cbndx;
> +	int ret;
>  
>  	fsr = arm_smmu_cb_read(smmu, idx, ARM_SMMU_CB_FSR);
>  	if (!(fsr & ARM_SMMU_FSR_FAULT))
> @@ -417,8 +418,12 @@ static irqreturn_t arm_smmu_context_fault(int irq, void *dev)
>  	iova = arm_smmu_cb_readq(smmu, idx, ARM_SMMU_CB_FAR);
>  	cbfrsynra = arm_smmu_gr1_read(smmu, ARM_SMMU_GR1_CBFRSYNRA(idx));
>  
> -	dev_err_ratelimited(smmu->dev,
> -	"Unhandled context fault: fsr=0x%x, iova=0x%08lx, fsynr=0x%x, cbfrsynra=0x%x, cb=%d\n",
> +	ret = report_iommu_fault(domain, NULL, iova,
> +		fsynr & ARM_SMMU_FSYNR0_WNR ? IOMMU_FAULT_WRITE : IOMMU_FAULT_READ);
> +
> +	if (ret == -ENOSYS)
> +		dev_err_ratelimited(smmu->dev,
> +		"Unhandled context fault: fsr=0x%x, iova=0x%08lx, fsynr=0x%x, cbfrsynra=0x%x, cb=%d\n",
>  			    fsr, iova, fsynr, cbfrsynra, idx);

Acked-by: Will Deacon <will@kernel.org>

Will