Re: [PATCH v5 1/5] iommu/arm-smmu: Add support for driver IOMMU fault handlers

From: Bjorn Andersson <bjorn.andersson@linaro.org>
To: Rob Clark <robdclark@gmail.com>
Cc: dri-devel@lists.freedesktop.org,
	iommu@lists.linux-foundation.org,
	Rob Clark <robdclark@chromium.org>,
	open list <linux-kernel@vger.kernel.org>,
	Will Deacon <will@kernel.org>,
	linux-arm-msm@vger.kernel.org,
	Robin Murphy <robin.murphy@arm.com>,
	Jordan Crouse <jcrouse@codeaurora.org>,
	freedreno@lists.freedesktop.org,
	"moderated list:ARM SMMU DRIVERS" 
	<linux-arm-kernel@lists.infradead.org>
Subject: Re: [PATCH v5 1/5] iommu/arm-smmu: Add support for driver IOMMU fault handlers
Date: Mon, 14 Jun 2021 12:26:06 -0500	[thread overview]
Message-ID: <YMeRLuMkiG4Uv0ZP@yoga> (raw)
In-Reply-To: <20210610214431.539029-2-robdclark@gmail.com>

On Thu 10 Jun 16:44 CDT 2021, 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>
> Acked-by: Will Deacon <will@kernel.org>

Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org>

Regards,
Bjorn

> ---
>  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);
>  
>  	arm_smmu_cb_write(smmu, idx, ARM_SMMU_CB_FSR, fsr);
> -- 
> 2.31.1
> 
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