From 2af2e72b18b499fa36d3f7379fd010ff25d2a984 Mon Sep 17 00:00:00 2001 From: Will Deacon Date: Tue, 2 Jul 2019 17:16:33 +0100 Subject: [PATCH] iommu/arm-smmu-v3: Defer TLB invalidation until ->iotlb_sync() Update the iommu_iotlb_gather structure passed to ->tlb_add_page() and use this information to defer all TLB invalidation until ->iotlb_sync(). This drastically reduces contention on the command queue, since we can insert our commands in batches rather than one-by-one. Tested-by: Ganapatrao Kulkarni Signed-off-by: Will Deacon --- drivers/iommu/arm-smmu-v3.c | 71 ++++++++++++++++++++++--------------- 1 file changed, 42 insertions(+), 29 deletions(-) diff --git a/drivers/iommu/arm-smmu-v3.c b/drivers/iommu/arm-smmu-v3.c index 202b4b6fc70a..b36a99971401 100644 --- a/drivers/iommu/arm-smmu-v3.c +++ b/drivers/iommu/arm-smmu-v3.c @@ -309,6 +309,13 @@ #define CMDQ_PROD_OWNED_FLAG Q_OVERFLOW_FLAG +/* + * This is used to size the command queue and therefore must be at least + * BITS_PER_LONG so that the valid_map works correctly (it relies on the + * total number of queue entries being a multiple of BITS_PER_LONG). + */ +#define CMDQ_BATCH_ENTRIES BITS_PER_LONG + #define CMDQ_0_OP GENMASK_ULL(7, 0) #define CMDQ_0_SSV (1UL << 11) @@ -1940,15 +1947,17 @@ static void arm_smmu_tlb_inv_context(void *cookie) arm_smmu_cmdq_issue_sync(smmu); } -static void arm_smmu_tlb_inv_range_nosync(unsigned long iova, size_t size, - size_t granule, bool leaf, void *cookie) +static void arm_smmu_tlb_inv_range(unsigned long iova, size_t size, + size_t granule, bool leaf, + struct arm_smmu_domain *smmu_domain) { - struct arm_smmu_domain *smmu_domain = cookie; + u64 cmds[CMDQ_BATCH_ENTRIES * CMDQ_ENT_DWORDS]; struct arm_smmu_device *smmu = smmu_domain->smmu; + unsigned long end = iova + size; + int i = 0; struct arm_smmu_cmdq_ent cmd = { .tlbi = { .leaf = leaf, - .addr = iova, }, }; @@ -1960,37 +1969,41 @@ static void arm_smmu_tlb_inv_range_nosync(unsigned long iova, size_t size, cmd.tlbi.vmid = smmu_domain->s2_cfg.vmid; } - do { - arm_smmu_cmdq_issue_cmd(smmu, &cmd); - cmd.tlbi.addr += granule; - } while (size -= granule); + while (iova < end) { + if (i == CMDQ_BATCH_ENTRIES) { + arm_smmu_cmdq_issue_cmdlist(smmu, cmds, i, false); + i = 0; + } + + cmd.tlbi.addr = iova; + arm_smmu_cmdq_build_cmd(&cmds[i * CMDQ_ENT_DWORDS], &cmd); + iova += granule; + i++; + } + + arm_smmu_cmdq_issue_cmdlist(smmu, cmds, i, true); } static void arm_smmu_tlb_inv_page_nosync(struct iommu_iotlb_gather *gather, unsigned long iova, size_t granule, void *cookie) { - arm_smmu_tlb_inv_range_nosync(iova, granule, granule, true, cookie); + struct arm_smmu_domain *smmu_domain = cookie; + struct iommu_domain *domain = &smmu_domain->domain; + + iommu_iotlb_gather_add_page(domain, gather, iova, granule); } static void arm_smmu_tlb_inv_walk(unsigned long iova, size_t size, size_t granule, void *cookie) { - struct arm_smmu_domain *smmu_domain = cookie; - struct arm_smmu_device *smmu = smmu_domain->smmu; - - arm_smmu_tlb_inv_range_nosync(iova, size, granule, false, cookie); - arm_smmu_cmdq_issue_sync(smmu); + arm_smmu_tlb_inv_range(iova, size, granule, false, cookie); } static void arm_smmu_tlb_inv_leaf(unsigned long iova, size_t size, size_t granule, void *cookie) { - struct arm_smmu_domain *smmu_domain = cookie; - struct arm_smmu_device *smmu = smmu_domain->smmu; - - arm_smmu_tlb_inv_range_nosync(iova, size, granule, true, cookie); - arm_smmu_cmdq_issue_sync(smmu); + arm_smmu_tlb_inv_range(iova, size, granule, true, cookie); } static const struct iommu_flush_ops arm_smmu_flush_ops = { @@ -2404,10 +2417,10 @@ static void arm_smmu_flush_iotlb_all(struct iommu_domain *domain) static void arm_smmu_iotlb_sync(struct iommu_domain *domain, struct iommu_iotlb_gather *gather) { - struct arm_smmu_device *smmu = to_smmu_domain(domain)->smmu; + struct arm_smmu_domain *smmu_domain = to_smmu_domain(domain); - if (smmu) - arm_smmu_cmdq_issue_sync(smmu); + arm_smmu_tlb_inv_range(gather->start, gather->end - gather->start, + gather->pgsize, true, smmu_domain); } static phys_addr_t @@ -3334,15 +3347,15 @@ static int arm_smmu_device_hw_probe(struct arm_smmu_device *smmu) /* Queue sizes, capped to ensure natural alignment */ smmu->cmdq.q.llq.max_n_shift = min_t(u32, CMDQ_MAX_SZ_SHIFT, FIELD_GET(IDR1_CMDQS, reg)); - if (smmu->cmdq.q.llq.max_n_shift < ilog2(BITS_PER_LONG)) { + if (smmu->cmdq.q.llq.max_n_shift <= ilog2(CMDQ_BATCH_ENTRIES)) { /* - * The cmdq valid_map relies on the total number of entries - * being a multiple of BITS_PER_LONG. There's also no way - * we can handle the weird alignment restrictions on the - * base pointer for a unit-length queue. + * We don't support splitting up batches, so one batch of + * commands plus an extra sync needs to fit inside the command + * queue. There's also no way we can handle the weird alignment + * restrictions on the base pointer for a unit-length queue. */ - dev_err(smmu->dev, "command queue size < %d entries not supported\n", - BITS_PER_LONG); + dev_err(smmu->dev, "command queue size <= %d entries not supported\n", + CMDQ_BATCH_ENTRIES); return -ENXIO; } -- 2.30.2