For PCI devices that support it, enable the PRI capability and handle
PRI Page Requests with the generic fault handler.

Signed-off-by: Jean-Philippe Brucker <jean-philippe.bruc...@arm.com>
---
 drivers/iommu/arm-smmu-v3.c | 174 ++++++++++++++++++++++++++++++--------------
 1 file changed, 119 insertions(+), 55 deletions(-)

diff --git a/drivers/iommu/arm-smmu-v3.c b/drivers/iommu/arm-smmu-v3.c
index 8d09615fab35..ace2f995b0c0 100644
--- a/drivers/iommu/arm-smmu-v3.c
+++ b/drivers/iommu/arm-smmu-v3.c
@@ -271,6 +271,7 @@
 #define STRTAB_STE_1_S1COR_SHIFT       4
 #define STRTAB_STE_1_S1CSH_SHIFT       6
 
+#define STRTAB_STE_1_PPAR              (1UL << 18)
 #define STRTAB_STE_1_S1STALLD          (1UL << 27)
 
 #define STRTAB_STE_1_EATS_ABT          0UL
@@ -346,9 +347,9 @@
 #define CMDQ_PRI_1_GRPID_SHIFT         0
 #define CMDQ_PRI_1_GRPID_MASK          0x1ffUL
 #define CMDQ_PRI_1_RESP_SHIFT          12
-#define CMDQ_PRI_1_RESP_DENY           (0UL << CMDQ_PRI_1_RESP_SHIFT)
-#define CMDQ_PRI_1_RESP_FAIL           (1UL << CMDQ_PRI_1_RESP_SHIFT)
-#define CMDQ_PRI_1_RESP_SUCC           (2UL << CMDQ_PRI_1_RESP_SHIFT)
+#define CMDQ_PRI_1_RESP_FAILURE                (0UL << CMDQ_PRI_1_RESP_SHIFT)
+#define CMDQ_PRI_1_RESP_INVALID                (1UL << CMDQ_PRI_1_RESP_SHIFT)
+#define CMDQ_PRI_1_RESP_SUCCESS                (2UL << CMDQ_PRI_1_RESP_SHIFT)
 
 #define CMDQ_RESUME_0_SID_SHIFT                32
 #define CMDQ_RESUME_0_SID_MASK         0xffffffffUL
@@ -442,12 +443,6 @@ module_param_named(disable_ats_check, disable_ats_check, 
bool, S_IRUGO);
 MODULE_PARM_DESC(disable_ats_check,
        "By default, the SMMU checks whether each incoming transaction marked 
as translated is allowed by the stream configuration. This option disables the 
check.");
 
-enum pri_resp {
-       PRI_RESP_DENY,
-       PRI_RESP_FAIL,
-       PRI_RESP_SUCC,
-};
-
 enum arm_smmu_msi_index {
        EVTQ_MSI_INDEX,
        GERROR_MSI_INDEX,
@@ -530,7 +525,7 @@ struct arm_smmu_cmdq_ent {
                        u32                     sid;
                        u32                     ssid;
                        u16                     grpid;
-                       enum pri_resp           resp;
+                       enum page_response_code resp;
                } pri;
 
                #define CMDQ_OP_RESUME          0x44
@@ -615,6 +610,7 @@ struct arm_smmu_strtab_ent {
        struct arm_smmu_s2_cfg          *s2_cfg;
 
        bool                            can_stall;
+       bool                            prg_resp_needs_ssid;
 };
 
 struct arm_smmu_strtab_cfg {
@@ -969,14 +965,14 @@ static int arm_smmu_cmdq_build_cmd(u64 *cmd, struct 
arm_smmu_cmdq_ent *ent)
                cmd[0] |= (u64)ent->pri.sid << CMDQ_PRI_0_SID_SHIFT;
                cmd[1] |= ent->pri.grpid << CMDQ_PRI_1_GRPID_SHIFT;
                switch (ent->pri.resp) {
-               case PRI_RESP_DENY:
-                       cmd[1] |= CMDQ_PRI_1_RESP_DENY;
+               case IOMMU_PAGE_RESP_FAILURE:
+                       cmd[1] |= CMDQ_PRI_1_RESP_FAILURE;
                        break;
-               case PRI_RESP_FAIL:
-                       cmd[1] |= CMDQ_PRI_1_RESP_FAIL;
+               case IOMMU_PAGE_RESP_INVALID:
+                       cmd[1] |= CMDQ_PRI_1_RESP_INVALID;
                        break;
-               case PRI_RESP_SUCC:
-                       cmd[1] |= CMDQ_PRI_1_RESP_SUCC;
+               case IOMMU_PAGE_RESP_SUCCESS:
+                       cmd[1] |= CMDQ_PRI_1_RESP_SUCCESS;
                        break;
                default:
                        return -EINVAL;
@@ -1180,9 +1176,16 @@ static int arm_smmu_page_response(struct iommu_domain 
*domain,
                cmd.resume.sid          = sid;
                cmd.resume.stag         = resp->page_req_group_id;
                cmd.resume.resp         = resp->resp_code;
+       } else if (master->can_fault) {
+               cmd.opcode              = CMDQ_OP_PRI_RESP;
+               cmd.substream_valid     = resp->pasid_present &&
+                                         master->ste.prg_resp_needs_ssid;
+               cmd.pri.sid             = sid;
+               cmd.pri.ssid            = resp->pasid;
+               cmd.pri.grpid           = resp->page_req_group_id;
+               cmd.pri.resp            = resp->resp_code;
        } else {
-               /* TODO: put PRI response here */
-               return -EINVAL;
+               return -ENODEV;
        }
 
        arm_smmu_cmdq_issue_cmd(master->smmu, &cmd);
@@ -1309,6 +1312,9 @@ static void arm_smmu_write_strtab_ent(struct 
arm_smmu_device *smmu, u32 sid,
                          STRTAB_STE_1_STRW_EL2 : STRTAB_STE_1_STRW_NSEL1) <<
                         STRTAB_STE_1_STRW_SHIFT);
 
+               if (ste->prg_resp_needs_ssid)
+                       dst[1] |= STRTAB_STE_1_PPAR;
+
                if (smmu->features & ARM_SMMU_FEAT_STALLS &&
                   !(smmu->features & ARM_SMMU_FEAT_STALL_FORCE) &&
                   !ste->can_stall)
@@ -1536,40 +1542,32 @@ static irqreturn_t arm_smmu_evtq_thread(int irq, void 
*dev)
 
 static void arm_smmu_handle_ppr(struct arm_smmu_device *smmu, u64 *evt)
 {
-       u32 sid, ssid;
-       u16 grpid;
-       bool ssv, last;
-
-       sid = evt[0] >> PRIQ_0_SID_SHIFT & PRIQ_0_SID_MASK;
-       ssv = evt[0] & PRIQ_0_SSID_V;
-       ssid = ssv ? evt[0] >> PRIQ_0_SSID_SHIFT & PRIQ_0_SSID_MASK : 0;
-       last = evt[0] & PRIQ_0_PRG_LAST;
-       grpid = evt[1] >> PRIQ_1_PRG_IDX_SHIFT & PRIQ_1_PRG_IDX_MASK;
-
-       dev_info(smmu->dev, "unexpected PRI request received:\n");
-       dev_info(smmu->dev,
-                "\tsid 0x%08x.0x%05x: [%u%s] %sprivileged %s%s%s access at 
iova 0x%016llx\n",
-                sid, ssid, grpid, last ? "L" : "",
-                evt[0] & PRIQ_0_PERM_PRIV ? "" : "un",
-                evt[0] & PRIQ_0_PERM_READ ? "R" : "",
-                evt[0] & PRIQ_0_PERM_WRITE ? "W" : "",
-                evt[0] & PRIQ_0_PERM_EXEC ? "X" : "",
-                evt[1] & PRIQ_1_ADDR_MASK << PRIQ_1_ADDR_SHIFT);
-
-       if (last) {
-               struct arm_smmu_cmdq_ent cmd = {
-                       .opcode                 = CMDQ_OP_PRI_RESP,
-                       .substream_valid        = ssv,
-                       .pri                    = {
-                               .sid    = sid,
-                               .ssid   = ssid,
-                               .grpid  = grpid,
-                               .resp   = PRI_RESP_DENY,
-                       },
-               };
+       u32 sid = evt[0] >> PRIQ_0_SID_SHIFT & PRIQ_0_SID_MASK;
 
-               arm_smmu_cmdq_issue_cmd(smmu, &cmd);
-       }
+       struct arm_smmu_master_data *master;
+       struct iommu_fault_event fault = {
+               .type           = IOMMU_FAULT_PAGE_REQ,
+               .last_req       = !!(evt[0] & PRIQ_0_PRG_LAST),
+               .pasid_valid    = !!(evt[0] & PRIQ_0_SSID_V),
+               .pasid          = evt[0] >> PRIQ_0_SSID_SHIFT & 
PRIQ_0_SSID_MASK,
+               .page_req_group_id = evt[1] >> PRIQ_1_PRG_IDX_SHIFT & 
PRIQ_1_PRG_IDX_MASK,
+               .addr           = evt[1] & PRIQ_1_ADDR_MASK << 
PRIQ_1_ADDR_SHIFT,
+       };
+
+       if (evt[0] & PRIQ_0_PERM_READ)
+               fault.prot |= IOMMU_FAULT_READ;
+       if (evt[0] & PRIQ_0_PERM_WRITE)
+               fault.prot |= IOMMU_FAULT_WRITE;
+       if (evt[0] & PRIQ_0_PERM_EXEC)
+               fault.prot |= IOMMU_FAULT_EXEC;
+       if (evt[0] & PRIQ_0_PERM_PRIV)
+               fault.prot |= IOMMU_FAULT_PRIV;
+
+       master = arm_smmu_find_master(smmu, sid);
+       if (WARN_ON(!master))
+               return;
+
+       iommu_report_device_fault(master->dev, &fault);
 }
 
 static irqreturn_t arm_smmu_priq_thread(int irq, void *dev)
@@ -1594,6 +1592,11 @@ static irqreturn_t arm_smmu_priq_thread(int irq, void 
*dev)
                }
 
                if (queue_sync_prod(q) == -EOVERFLOW)
+                       /*
+                        * TODO: flush pending faults, since the SMMU might have
+                        * auto-responded to the Last request of a pending
+                        * group
+                        */
                        dev_err(smmu->dev, "PRIQ overflow detected -- requests 
lost\n");
        } while (!queue_empty(q));
 
@@ -1647,7 +1650,8 @@ static int arm_smmu_flush_queues(struct notifier_block 
*nb,
        if (master) {
                if (master->ste.can_stall)
                        arm_smmu_flush_queue(smmu, &smmu->evtq.q, "evtq");
-               /* TODO: add support for PRI */
+               else if (master->can_fault)
+                       arm_smmu_flush_queue(smmu, &smmu->priq.q, "priq");
                return 0;
        }
 
@@ -2533,6 +2537,46 @@ static int arm_smmu_enable_ats(struct 
arm_smmu_master_data *master)
        return 0;
 }
 
+static int arm_smmu_enable_pri(struct arm_smmu_master_data *master)
+{
+       int ret, pos;
+       struct pci_dev *pdev;
+       /*
+        * TODO: find a good inflight PPR number. We should divide the PRI queue
+        * by the number of PRI-capable devices, but it's impossible to know
+        * about current and future (hotplugged) devices. So we're at risk of
+        * dropping PPRs (and leaking pending requests in the FQ).
+        */
+       size_t max_inflight_pprs = 16;
+       struct arm_smmu_device *smmu = master->smmu;
+
+       if (!(smmu->features & ARM_SMMU_FEAT_PRI) || !dev_is_pci(master->dev))
+               return -ENOSYS;
+
+       pdev = to_pci_dev(master->dev);
+
+       pos = pci_find_ext_capability(pdev, PCI_EXT_CAP_ID_PRI);
+       if (!pos)
+               return -ENOSYS;
+
+       ret = pci_reset_pri(pdev);
+       if (ret)
+               return ret;
+
+       ret = pci_enable_pri(pdev, max_inflight_pprs);
+       if (ret) {
+               dev_err(master->dev, "cannot enable PRI: %d\n", ret);
+               return ret;
+       }
+
+       master->can_fault = true;
+       master->ste.prg_resp_needs_ssid = pci_prg_resp_requires_prefix(pdev);
+
+       dev_dbg(master->dev, "enabled PRI");
+
+       return 0;
+}
+
 static void arm_smmu_disable_ats(struct arm_smmu_master_data *master)
 {
        struct pci_dev *pdev;
@@ -2548,6 +2592,22 @@ static void arm_smmu_disable_ats(struct 
arm_smmu_master_data *master)
        pci_disable_ats(pdev);
 }
 
+static void arm_smmu_disable_pri(struct arm_smmu_master_data *master)
+{
+       struct pci_dev *pdev;
+
+       if (!dev_is_pci(master->dev))
+               return;
+
+       pdev = to_pci_dev(master->dev);
+
+       if (!pdev->pri_enabled)
+               return;
+
+       pci_disable_pri(pdev);
+       master->can_fault = false;
+}
+
 static int arm_smmu_insert_master(struct arm_smmu_device *smmu,
                                  struct arm_smmu_master_data *master)
 {
@@ -2668,12 +2728,13 @@ static int arm_smmu_add_device(struct device *dev)
                master->ste.can_stall = true;
        }
 
-       arm_smmu_enable_ats(master);
+       if (!arm_smmu_enable_ats(master))
+               arm_smmu_enable_pri(master);
 
        group = iommu_group_get_for_dev(dev);
        if (IS_ERR(group)) {
                ret = PTR_ERR(group);
-               goto err_disable_ats;
+               goto err_disable_pri;
        }
 
        iommu_group_put(group);
@@ -2682,7 +2743,8 @@ static int arm_smmu_add_device(struct device *dev)
 
        return 0;
 
-err_disable_ats:
+err_disable_pri:
+       arm_smmu_disable_pri(master);
        arm_smmu_disable_ats(master);
 
        return ret;
@@ -2702,6 +2764,8 @@ static void arm_smmu_remove_device(struct device *dev)
        if (master && master->ste.assigned)
                arm_smmu_detach_dev(dev);
        arm_smmu_remove_master(smmu, master);
+
+       arm_smmu_disable_pri(master);
        arm_smmu_disable_ats(master);
 
        iommu_group_remove_device(dev);
-- 
2.15.1

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