iommu/arm-smmu-v3: Add command queue batching helpers

As more functions will implement command queue batching, add two helpers
to simplify building a command list.

Signed-off-by: Jean-Philippe Brucker <jean-philippe@linaro.org>
Signed-off-by: Will Deacon <will@kernel.org>

diff --git a/drivers/iommu/arm-smmu-v3.c b/drivers/iommu/arm-smmu-v3.c
index 068a16d..beeec36 100644 (file)
--- a/drivers/iommu/arm-smmu-v3.c
+++ b/drivers/iommu/arm-smmu-v3.c
@@ -548,6 +548,11 @@ struct arm_smmu_cmdq {
        atomic_t                        lock;
 };
 
+struct arm_smmu_cmdq_batch {
+       u64                             cmds[CMDQ_BATCH_ENTRIES * CMDQ_ENT_DWORDS];
+       int                             num;
+};
+
 struct arm_smmu_evtq {
        struct arm_smmu_queue           q;
        u32                             max_stalls;
@@ -1482,6 +1487,24 @@ static int arm_smmu_cmdq_issue_sync(struct arm_smmu_device *smmu)
        return arm_smmu_cmdq_issue_cmdlist(smmu, NULL, 0, true);
 }
 
+static void arm_smmu_cmdq_batch_add(struct arm_smmu_device *smmu,
+                                   struct arm_smmu_cmdq_batch *cmds,
+                                   struct arm_smmu_cmdq_ent *cmd)
+{
+       if (cmds->num == CMDQ_BATCH_ENTRIES) {
+               arm_smmu_cmdq_issue_cmdlist(smmu, cmds->cmds, cmds->num, false);
+               cmds->num = 0;
+       }
+       arm_smmu_cmdq_build_cmd(&cmds->cmds[cmds->num * CMDQ_ENT_DWORDS], cmd);
+       cmds->num++;
+}
+
+static int arm_smmu_cmdq_batch_submit(struct arm_smmu_device *smmu,
+                                     struct arm_smmu_cmdq_batch *cmds)
+{
+       return arm_smmu_cmdq_issue_cmdlist(smmu, cmds->cmds, cmds->num, true);
+}
+
 /* Context descriptor manipulation functions */
 static void arm_smmu_sync_cd(struct arm_smmu_domain *smmu_domain,
                             int ssid, bool leaf)
@@ -2220,10 +2243,9 @@ static void arm_smmu_tlb_inv_range(unsigned long iova, size_t size,
                                   size_t granule, bool leaf,
                                   struct arm_smmu_domain *smmu_domain)
 {
-       u64 cmds[CMDQ_BATCH_ENTRIES * CMDQ_ENT_DWORDS];
        struct arm_smmu_device *smmu = smmu_domain->smmu;
        unsigned long start = iova, end = iova + size;
-       int i = 0;
+       struct arm_smmu_cmdq_batch cmds = {};
        struct arm_smmu_cmdq_ent cmd = {
                .tlbi = {
                        .leaf   = leaf,
@@ -2242,18 +2264,11 @@ static void arm_smmu_tlb_inv_range(unsigned long iova, size_t size,
        }
 
        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);
+               arm_smmu_cmdq_batch_add(smmu, &cmds, &cmd);
                iova += granule;
-               i++;
        }
-
-       arm_smmu_cmdq_issue_cmdlist(smmu, cmds, i, true);
+       arm_smmu_cmdq_batch_submit(smmu, &cmds);
 
        /*
         * Unfortunately, this can't be leaf-only since we may have