From fac956710ab0812f9e395e9f7a27da551412830f Mon Sep 17 00:00:00 2001 From: John Garry Date: Wed, 11 Aug 2021 23:49:26 +0800 Subject: iommu/arm-smmu-v3: Stop pre-zeroing batch commands Pre-zeroing the batched commands structure is inefficient, as individual commands are zeroed later in arm_smmu_cmdq_build_cmd(). The size is quite large and commonly most commands won't even be used: struct arm_smmu_cmdq_batch cmds = {}; 345c: 52800001 mov w1, #0x0 // #0 3460: d2808102 mov x2, #0x408 // #1032 3464: 910143a0 add x0, x29, #0x50 3468: 94000000 bl 0 Stop pre-zeroing the complete structure and only zero the num member. Signed-off-by: John Garry Link: https://lore.kernel.org/r/1628696966-88386-1-git-send-email-john.garry@huawei.com Signed-off-by: Will Deacon --- drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c | 12 +++++++++--- 1 file changed, 9 insertions(+), 3 deletions(-) (limited to 'drivers/iommu/arm') diff --git a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c index 283bfad5f28f..3216e746c28a 100644 --- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c +++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c @@ -955,7 +955,7 @@ static void arm_smmu_sync_cd(struct arm_smmu_domain *smmu_domain, size_t i; unsigned long flags; struct arm_smmu_master *master; - struct arm_smmu_cmdq_batch cmds = {}; + struct arm_smmu_cmdq_batch cmds; struct arm_smmu_device *smmu = smmu_domain->smmu; struct arm_smmu_cmdq_ent cmd = { .opcode = CMDQ_OP_CFGI_CD, @@ -965,6 +965,8 @@ static void arm_smmu_sync_cd(struct arm_smmu_domain *smmu_domain, }, }; + cmds.num = 0; + spin_lock_irqsave(&smmu_domain->devices_lock, flags); list_for_each_entry(master, &smmu_domain->devices, domain_head) { for (i = 0; i < master->num_streams; i++) { @@ -1781,7 +1783,7 @@ int arm_smmu_atc_inv_domain(struct arm_smmu_domain *smmu_domain, int ssid, unsigned long flags; struct arm_smmu_cmdq_ent cmd; struct arm_smmu_master *master; - struct arm_smmu_cmdq_batch cmds = {}; + struct arm_smmu_cmdq_batch cmds; if (!(smmu_domain->smmu->features & ARM_SMMU_FEAT_ATS)) return 0; @@ -1805,6 +1807,8 @@ int arm_smmu_atc_inv_domain(struct arm_smmu_domain *smmu_domain, int ssid, arm_smmu_atc_inv_to_cmd(ssid, iova, size, &cmd); + cmds.num = 0; + spin_lock_irqsave(&smmu_domain->devices_lock, flags); list_for_each_entry(master, &smmu_domain->devices, domain_head) { if (!master->ats_enabled) @@ -1852,7 +1856,7 @@ static void __arm_smmu_tlb_inv_range(struct arm_smmu_cmdq_ent *cmd, struct arm_smmu_device *smmu = smmu_domain->smmu; unsigned long end = iova + size, num_pages = 0, tg = 0; size_t inv_range = granule; - struct arm_smmu_cmdq_batch cmds = {}; + struct arm_smmu_cmdq_batch cmds; if (!size) return; @@ -1870,6 +1874,8 @@ static void __arm_smmu_tlb_inv_range(struct arm_smmu_cmdq_ent *cmd, num_pages = size >> tg; } + cmds.num = 0; + while (iova < end) { if (smmu->features & ARM_SMMU_FEAT_RANGE_INV) { /* -- cgit v1.2.3-59-g8ed1b