Commit ec560166 authored by AngeloGioacchino Del Regno's avatar AngeloGioacchino Del Regno Committed by Will Deacon
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iommu/qcom: Index contexts by asid number to allow asid 0 



This driver was indexing the contexts by asid-1, which is probably
done under the assumption that the first ASID is always 1.
Unfortunately this is not always true: at least for MSM8956 and
MSM8976's GPU IOMMU, the gpu_user context's ASID number is zero.
To allow using a zero asid number, index the contexts by `asid`
instead of by `asid - 1`.

While at it, also enhance human readability by renaming the
`num_ctxs` member of struct qcom_iommu_dev to `max_asid`.

Signed-off-by: default avatarAngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Reviewed-by: default avatarKonrad Dybcio <konrad.dybcio@linaro.org>
Link: https://lore.kernel.org/r/20230622092742.74819-5-angelogioacchino.delregno@collabora.com


Signed-off-by: default avatarWill Deacon <will@kernel.org>
parent 9f3fef23

drivers/iommu/arm/arm-smmu/qcom_iommu.c

+10 −12
Original line number Diff line number Diff line
@@ -51,8 +51,8 @@ struct qcom_iommu_dev { 
	struct clk_bulk_data clks[CLK_NUM];

	void __iomem		*local_base;

	u32			 sec_id;

	u8			 num_ctxs;

	struct qcom_iommu_ctx	*ctxs[];   /* indexed by asid-1 */

	u8			 max_asid;

	struct qcom_iommu_ctx	*ctxs[];   /* indexed by asid */

};



struct qcom_iommu_ctx {
@@ -94,7 +94,7 @@ static struct qcom_iommu_ctx * to_ctx(struct qcom_iommu_domain *d, unsigned asid 
	struct qcom_iommu_dev *qcom_iommu = d->iommu;

	if (!qcom_iommu)

		return NULL;

	return qcom_iommu->ctxs[asid - 1];

	return qcom_iommu->ctxs[asid];

}



static inline void
@@ -534,12 +534,10 @@ static int qcom_iommu_of_xlate(struct device *dev, struct of_phandle_args *args) 
	qcom_iommu = platform_get_drvdata(iommu_pdev);



	/* make sure the asid specified in dt is valid, so we don't have

	 * to sanity check this elsewhere, since 'asid - 1' is used to

	 * index into qcom_iommu->ctxs:

	 * to sanity check this elsewhere:

	 */

	if (WARN_ON(asid < 1) ||

	    WARN_ON(asid > qcom_iommu->num_ctxs) ||

	    WARN_ON(qcom_iommu->ctxs[asid - 1] == NULL)) {

	if (WARN_ON(asid > qcom_iommu->max_asid) ||

	    WARN_ON(qcom_iommu->ctxs[asid] == NULL)) {

		put_device(&iommu_pdev->dev);

		return -EINVAL;

	}
@@ -694,7 +692,7 @@ static int qcom_iommu_ctx_probe(struct platform_device *pdev) 


	dev_dbg(dev, "found asid %u\n", ctx->asid);



	qcom_iommu->ctxs[ctx->asid - 1] = ctx;

	qcom_iommu->ctxs[ctx->asid] = ctx;



	return 0;

}
@@ -706,7 +704,7 @@ static void qcom_iommu_ctx_remove(struct platform_device *pdev) 


	platform_set_drvdata(pdev, NULL);



	qcom_iommu->ctxs[ctx->asid - 1] = NULL;

	qcom_iommu->ctxs[ctx->asid] = NULL;

}



static const struct of_device_id ctx_of_match[] = {
@@ -753,11 +751,11 @@ static int qcom_iommu_device_probe(struct platform_device *pdev) 
	for_each_child_of_node(dev->of_node, child)

		max_asid = max(max_asid, get_asid(child));



	qcom_iommu = devm_kzalloc(dev, struct_size(qcom_iommu, ctxs, max_asid),

	qcom_iommu = devm_kzalloc(dev, struct_size(qcom_iommu, ctxs, max_asid + 1),

				  GFP_KERNEL);

	if (!qcom_iommu)

		return -ENOMEM;

	qcom_iommu->num_ctxs = max_asid;

	qcom_iommu->max_asid = max_asid;

	qcom_iommu->dev = dev;



	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);