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 <memset>
Stop pre-zeroing the complete structure and only zero the num member.
Signed-off-by: John Garry <john.ga...@huawei.com>
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 cbc57edfa4e2..2a4f3fb938f6 100644
--- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
+++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
@@ -1082,7 +1082,7 @@ 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,
@@ -1092,6 +1092,8 @@ 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++) {
@@ -1908,7 +1910,7 @@ 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;
@@ -1932,6 +1934,8 @@ 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)
@@ -1980,7 +1984,7 @@ 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;
@@ -1998,6 +2002,8 @@ 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) {
/*
--
2.26.2
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