From ec5601661bfcdc206e6ceba1b97837e763dab1ba Mon Sep 17 00:00:00 2001 From: AngeloGioacchino Del Regno Date: Thu, 22 Jun 2023 11:27:40 +0200 Subject: [PATCH] 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: AngeloGioacchino Del Regno Reviewed-by: Konrad Dybcio Link: https://lore.kernel.org/r/20230622092742.74819-5-angelogioacchino.delregno@collabora.com Signed-off-by: Will Deacon --- drivers/iommu/arm/arm-smmu/qcom_iommu.c | 22 ++++++++++------------ 1 file changed, 10 insertions(+), 12 deletions(-) diff --git a/drivers/iommu/arm/arm-smmu/qcom_iommu.c b/drivers/iommu/arm/arm-smmu/qcom_iommu.c index a352859..60e4959 100644 --- a/drivers/iommu/arm/arm-smmu/qcom_iommu.c +++ b/drivers/iommu/arm/arm-smmu/qcom_iommu.c @@ -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); -- 2.7.4