From: Long Li <[email protected]>

When MANA is being probed, it's possible that hardware is in recovery
mode and the device may get GDMA_EQE_HWC_RESET_REQUEST over HWC in the
middle of the probe. Detect such condition and go through the recovery
service procedure.

Fixes: fbe346ce9d62 ("net: mana: Handle Reset Request from MANA NIC")
Signed-off-by: Long Li <[email protected]>
---
 .../net/ethernet/microsoft/mana/gdma_main.c   | 131 +++++++++++++++---
 include/net/mana/gdma.h                       |   9 +-
 2 files changed, 122 insertions(+), 18 deletions(-)

diff --git a/drivers/net/ethernet/microsoft/mana/gdma_main.c 
b/drivers/net/ethernet/microsoft/mana/gdma_main.c
index effe0a2f207a..1d9c2beb22b2 100644
--- a/drivers/net/ethernet/microsoft/mana/gdma_main.c
+++ b/drivers/net/ethernet/microsoft/mana/gdma_main.c
@@ -15,6 +15,12 @@
 
 struct dentry *mana_debugfs_root;
 
+static struct mana_serv_delayed_work {
+       struct delayed_work work;
+       struct pci_dev *pdev;
+       enum gdma_eqe_type type;
+} mns_delayed_wk;
+
 static u32 mana_gd_r32(struct gdma_context *g, u64 offset)
 {
        return readl(g->bar0_va + offset);
@@ -387,6 +393,25 @@ EXPORT_SYMBOL_NS(mana_gd_ring_cq, "NET_MANA");
 
 #define MANA_SERVICE_PERIOD 10
 
+static void mana_serv_rescan(struct pci_dev *pdev)
+{
+       struct pci_bus *parent;
+
+       pci_lock_rescan_remove();
+
+       parent = pdev->bus;
+       if (!parent) {
+               dev_err(&pdev->dev, "MANA service: no parent bus\n");
+               goto out;
+       }
+
+       pci_stop_and_remove_bus_device(pdev);
+       pci_rescan_bus(parent);
+
+out:
+       pci_unlock_rescan_remove();
+}
+
 static void mana_serv_fpga(struct pci_dev *pdev)
 {
        struct pci_bus *bus, *parent;
@@ -419,9 +444,12 @@ static void mana_serv_reset(struct pci_dev *pdev)
 {
        struct gdma_context *gc = pci_get_drvdata(pdev);
        struct hw_channel_context *hwc;
+       int ret;
 
        if (!gc) {
-               dev_err(&pdev->dev, "MANA service: no GC\n");
+               /* Perform PCI rescan on device if GC is not set up */
+               dev_err(&pdev->dev, "MANA service: GC not setup, rescanning\n");
+               mana_serv_rescan(pdev);
                return;
        }
 
@@ -440,9 +468,18 @@ static void mana_serv_reset(struct pci_dev *pdev)
 
        msleep(MANA_SERVICE_PERIOD * 1000);
 
-       mana_gd_resume(pdev);
+       ret = mana_gd_resume(pdev);
+       if (ret == -ETIMEDOUT || ret == -EPROTO) {
+               /* Perform PCI rescan on device if we failed on HWC */
+               dev_err(&pdev->dev, "MANA service: resume failed, 
rescanning\n");
+               mana_serv_rescan(pdev);
+               goto out;
+       }
 
-       dev_info(&pdev->dev, "MANA reset cycle completed\n");
+       if (ret)
+               dev_info(&pdev->dev, "MANA reset cycle failed err %d\n", ret);
+       else
+               dev_info(&pdev->dev, "MANA reset cycle completed\n");
 
 out:
        gc->in_service = false;
@@ -454,18 +491,9 @@ struct mana_serv_work {
        enum gdma_eqe_type type;
 };
 
-static void mana_serv_func(struct work_struct *w)
+static void mana_do_service(enum gdma_eqe_type type, struct pci_dev *pdev)
 {
-       struct mana_serv_work *mns_wk;
-       struct pci_dev *pdev;
-
-       mns_wk = container_of(w, struct mana_serv_work, serv_work);
-       pdev = mns_wk->pdev;
-
-       if (!pdev)
-               goto out;
-
-       switch (mns_wk->type) {
+       switch (type) {
        case GDMA_EQE_HWC_FPGA_RECONFIG:
                mana_serv_fpga(pdev);
                break;
@@ -475,12 +503,36 @@ static void mana_serv_func(struct work_struct *w)
                break;
 
        default:
-               dev_err(&pdev->dev, "MANA service: unknown type %d\n",
-                       mns_wk->type);
+               dev_err(&pdev->dev, "MANA service: unknown type %d\n", type);
                break;
        }
+}
+
+static void mana_serv_delayed_func(struct work_struct *w)
+{
+       struct mana_serv_delayed_work *dwork;
+       struct pci_dev *pdev;
+
+       dwork = container_of(w, struct mana_serv_delayed_work, work.work);
+       pdev = dwork->pdev;
+
+       if (pdev)
+               mana_do_service(dwork->type, pdev);
+
+       pci_dev_put(pdev);
+}
+
+static void mana_serv_func(struct work_struct *w)
+{
+       struct mana_serv_work *mns_wk;
+       struct pci_dev *pdev;
+
+       mns_wk = container_of(w, struct mana_serv_work, serv_work);
+       pdev = mns_wk->pdev;
+
+       if (pdev)
+               mana_do_service(mns_wk->type, pdev);
 
-out:
        pci_dev_put(pdev);
        kfree(mns_wk);
        module_put(THIS_MODULE);
@@ -541,6 +593,17 @@ static void mana_gd_process_eqe(struct gdma_queue *eq)
        case GDMA_EQE_HWC_RESET_REQUEST:
                dev_info(gc->dev, "Recv MANA service type:%d\n", type);
 
+               if (atomic_inc_return(&gc->in_probe) == 1) {
+                       /*
+                        * Device is in probe and we received an hardware reset
+                        * event, probe() will detect that "in_probe" has
+                        * changed and perform service procedure.
+                        */
+                       dev_info(gc->dev,
+                                "Service is to be processed in probe\n");
+                       break;
+               }
+
                if (gc->in_service) {
                        dev_info(gc->dev, "Already in service\n");
                        break;
@@ -1930,6 +1993,8 @@ static int mana_gd_probe(struct pci_dev *pdev, const 
struct pci_device_id *ent)
                gc->mana_pci_debugfs = 
debugfs_create_dir(pci_slot_name(pdev->slot),
                                                          mana_debugfs_root);
 
+       atomic_set(&gc->in_probe, 0);
+
        err = mana_gd_setup(pdev);
        if (err)
                goto unmap_bar;
@@ -1942,8 +2007,19 @@ static int mana_gd_probe(struct pci_dev *pdev, const 
struct pci_device_id *ent)
        if (err)
                goto cleanup_mana;
 
+       /*
+        * If a hardware reset event has occurred over HWC during probe,
+        * rollback and perform hardware reset procedure.
+        */
+       if (atomic_inc_return(&gc->in_probe) > 1) {
+               err = -EPROTO;
+               goto cleanup_mana_rdma;
+       }
+
        return 0;
 
+cleanup_mana_rdma:
+       mana_rdma_remove(&gc->mana_ib);
 cleanup_mana:
        mana_remove(&gc->mana, false);
 cleanup_gd:
@@ -1967,6 +2043,25 @@ static int mana_gd_probe(struct pci_dev *pdev, const 
struct pci_device_id *ent)
 disable_dev:
        pci_disable_device(pdev);
        dev_err(&pdev->dev, "gdma probe failed: err = %d\n", err);
+
+       /*
+        * Hardware could be in recovery mode and the HWC returns TIMEDOUT or
+        * EPROTO from mana_gd_setup(), mana_probe() or mana_rdma_probe(), or
+        * we received a hardware reset event over HWC interrupt. In this case,
+        * perform the device recovery procedure after MANA_SERVICE_PERIOD
+        * seconds.
+        */
+       if (err == -ETIMEDOUT || err == -EPROTO) {
+               dev_info(&pdev->dev, "Start MANA recovery mode\n");
+
+               mns_delayed_wk.pdev = pci_dev_get(pdev);
+               mns_delayed_wk.type = GDMA_EQE_HWC_RESET_REQUEST;
+
+               INIT_DELAYED_WORK(&mns_delayed_wk.work, mana_serv_delayed_func);
+               schedule_delayed_work(&mns_delayed_wk.work,
+                                     secs_to_jiffies(MANA_SERVICE_PERIOD));
+       }
+
        return err;
 }
 
@@ -2084,6 +2179,8 @@ static int __init mana_driver_init(void)
 
 static void __exit mana_driver_exit(void)
 {
+       cancel_delayed_work_sync(&mns_delayed_wk.work);
+
        pci_unregister_driver(&mana_driver);
 
        debugfs_remove(mana_debugfs_root);
diff --git a/include/net/mana/gdma.h b/include/net/mana/gdma.h
index 637f42485dba..1bb4c6ada2b6 100644
--- a/include/net/mana/gdma.h
+++ b/include/net/mana/gdma.h
@@ -430,6 +430,9 @@ struct gdma_context {
        u64 pf_cap_flags1;
 
        struct workqueue_struct *service_wq;
+
+       /* Count how many times we have finished probe or HWC events */
+       atomic_t                in_probe;
 };
 
 static inline bool mana_gd_is_mana(struct gdma_dev *gd)
@@ -592,6 +595,9 @@ enum {
 #define GDMA_DRV_CAP_FLAG_1_HANDLE_RECONFIG_EQE BIT(17)
 #define GDMA_DRV_CAP_FLAG_1_HW_VPORT_LINK_AWARE BIT(6)
 
+/* Driver can handle hardware reset events during probe */
+#define GDMA_DRV_CAP_FLAG_1_RECOVER_PROBE BIT(22)
+
 #define GDMA_DRV_CAP_FLAGS1 \
        (GDMA_DRV_CAP_FLAG_1_EQ_SHARING_MULTI_VPORT | \
         GDMA_DRV_CAP_FLAG_1_NAPI_WKDONE_FIX | \
@@ -601,7 +607,8 @@ enum {
         GDMA_DRV_CAP_FLAG_1_DYNAMIC_IRQ_ALLOC_SUPPORT | \
         GDMA_DRV_CAP_FLAG_1_SELF_RESET_ON_EQE | \
         GDMA_DRV_CAP_FLAG_1_HANDLE_RECONFIG_EQE | \
-        GDMA_DRV_CAP_FLAG_1_HW_VPORT_LINK_AWARE)
+        GDMA_DRV_CAP_FLAG_1_HW_VPORT_LINK_AWARE | \
+        GDMA_DRV_CAP_FLAG_1_RECOVER_PROBE)
 
 #define GDMA_DRV_CAP_FLAGS2 0
 
-- 
2.43.0


Reply via email to