[RFC,v2,13/20] hw/arm/smmuv3-accel: Introduce helpers to batch and issue cache invalidations

Commit Message

Shameer Kolothum March 11, 2025, 2:10 p.m. UTC

From: Nicolin Chen <[e-mail]>

Inroduce an SMMUCommandBatch and some helpers to batch and issue the
commands.  Currently separate out TLBI commands and device cache commands
to avoid some errata on certain versions of SMMUs. Later it should check
IIDR register to detect if underlying SMMU hw has such an erratum.

Signed-off-by: Nicolin Chen <[e-mail]>
Signed-off-by: Shameer Kolothum <[e-mail]>
---
 hw/arm/smmuv3-accel.c    | 69 ++++++++++++++++++++++++++++++++++++++++
 hw/arm/smmuv3-internal.h | 29 +++++++++++++++++
 2 files changed, 98 insertions(+)

Patch

diff --git a/hw/arm/smmuv3-accel.c b/hw/arm/smmuv3-accel.c
index 76134d106a..09be838d22 100644
--- a/hw/arm/smmuv3-accel.c
+++ b/hw/arm/smmuv3-accel.c
@@ -160,6 +160,75 @@  void smmuv3_accel_install_nested_ste(SMMUDevice *sdev, int sid)
                                           nested_data.ste[0]);
 }
 
+/* Update batch->ncmds to the number of execute cmds */
+int smmuv3_accel_issue_cmd_batch(SMMUState *bs, SMMUCommandBatch *batch)
+{
+    SMMUv3AccelState *s_accel = ARM_SMMUV3_ACCEL(bs);
+    uint32_t total = batch->ncmds;
+    IOMMUFDViommu *viommu_core;
+    int ret;
+
+    if (!bs->accel) {
+        return 0;
+    }
+
+    if (!s_accel->viommu) {
+        return 0;
+    }
+    viommu_core = &s_accel->viommu->core;
+    ret = iommufd_backend_invalidate_cache(viommu_core->iommufd,
+                                           viommu_core->viommu_id,
+                                           IOMMU_VIOMMU_INVALIDATE_DATA_ARM_SMMUV3,
+                                           sizeof(Cmd), &batch->ncmds,
+                                           batch->cmds);
+    if (total != batch->ncmds) {
+        error_report("%s failed: ret=%d, total=%d, done=%d",
+                      __func__, ret, total, batch->ncmds);
+        return ret;
+    }
+
+    batch->ncmds = 0;
+    batch->dev_cache = false;
+    return ret;
+}
+
+int smmuv3_accel_batch_cmds(SMMUState *bs, SMMUDevice *sdev,
+                            SMMUCommandBatch *batch, Cmd *cmd,
+                            uint32_t *cons, bool dev_cache)
+{
+    int ret;
+
+    if (!bs->accel) {
+        return 0;
+    }
+
+    if (sdev) {
+        SMMUv3AccelDevice *accel_dev;
+        accel_dev = container_of(sdev, SMMUv3AccelDevice, sdev);
+        if (!accel_dev->s1_hwpt) {
+            return 0;
+        }
+    }
+
+    /*
+     * Currently separate out dev_cache and hwpt for safety, which might
+     * not be necessary if underlying HW SMMU does not have the errata.
+     *
+     * TODO check IIDR register values read from hw_info.
+     */
+    if (batch->ncmds && (dev_cache != batch->dev_cache)) {
+        ret = smmuv3_accel_issue_cmd_batch(bs, batch);
+        if (ret) {
+            *cons = batch->cons[batch->ncmds];
+            return ret;
+        }
+    }
+    batch->dev_cache = dev_cache;
+    batch->cmds[batch->ncmds] = *cmd;
+    batch->cons[batch->ncmds++] = *cons;
+    return 0;
+}
+
 static bool
 smmuv3_accel_dev_attach_viommu(SMMUv3AccelDevice *accel_dev,
                                HostIOMMUDeviceIOMMUFD *idev, Error **errp)
diff --git a/hw/arm/smmuv3-internal.h b/hw/arm/smmuv3-internal.h
index 46c8bcae14..4602ae6728 100644
--- a/hw/arm/smmuv3-internal.h
+++ b/hw/arm/smmuv3-internal.h
@@ -549,13 +549,42 @@  typedef struct CD {
     uint32_t word[16];
 } CD;
 
+/**
+ * SMMUCommandBatch - batch of invalidation commands for smmuv3-accel
+ * @cmds: Pointer to list of commands
+ * @cons: Pointer to list of CONS corresponding to the commands
+ * @ncmds: Total ncmds in the batch
+ * @dev_cache: Issue to a device cache
+ */
+typedef struct SMMUCommandBatch {
+    Cmd *cmds;
+    uint32_t *cons;
+    uint32_t ncmds;
+    bool dev_cache;
+} SMMUCommandBatch;
+
 int smmu_find_ste(SMMUv3State *s, uint32_t sid, STE *ste,
                   SMMUEventInfo *event);
 void smmuv3_flush_config(SMMUDevice *sdev);
 
 #if defined(CONFIG_ARM_SMMUV3_ACCEL) && defined(CONFIG_IOMMUFD)
+int smmuv3_accel_issue_cmd_batch(SMMUState *bs, SMMUCommandBatch *batch);
+int smmuv3_accel_batch_cmds(SMMUState *bs, SMMUDevice *sdev,
+                            SMMUCommandBatch *batch, Cmd *cmd,
+                            uint32_t *cons, bool dev_cache);
 void smmuv3_accel_install_nested_ste(SMMUDevice *sdev, int sid);
 #else
+static inline int smmuv3_accel_issue_cmd_batch(SMMUState *bs,
+                                               SMMUCommandBatch *batch)
+{
+    return 0;
+}
+static inline int smmuv3_accel_batch_cmds(SMMUState *bs, SMMUDevice *sdev,
+                                          SMMUCommandBatch *batch, Cmd *cmd,
+                                          uint32_t *cons, bool dev_cache)
+{
+    return 0;
+}
 static inline void smmuv3_accel_install_nested_ste(SMMUDevice *sdev, int sid)
 {
 }