To collaborate with hardware servicing events, upon receiving the special
EQE notification from the HW channel, remove the devices on this bus.
Then, after a waiting period based on the device specs, rescan the parent
bus to recover the devices.

Signed-off-by: Haiyang Zhang <haiya...@microsoft.com>
Reviewed-by: Shradha Gupta <shradhagu...@linux.microsoft.com>
Reviewed-by: Simon Horman <ho...@kernel.org>
---
v6:
Not acquiring module refcnt as suggested by Paolo Abeni.

v5:
Get refcnt of the pdev struct to avoid removal before running the work
as suggested by Jakub Kicinski.

v4:
Renamed EQE type 135 to GDMA_EQE_HWC_RESET_REQUEST, since there can
be multiple cases of this reset request.

v3:
Updated for checkpatch warnings as suggested by Simon Horman.

v2:
Added dev_dbg for service type as suggested by Shradha Gupta.
Added driver cap bit.
---
 .../net/ethernet/microsoft/mana/gdma_main.c   | 67 +++++++++++++++++++
 include/net/mana/gdma.h                       | 10 ++-
 2 files changed, 75 insertions(+), 2 deletions(-)

diff --git a/drivers/net/ethernet/microsoft/mana/gdma_main.c 
b/drivers/net/ethernet/microsoft/mana/gdma_main.c
index 4ffaf7588885..999cf7f88d5d 100644
--- a/drivers/net/ethernet/microsoft/mana/gdma_main.c
+++ b/drivers/net/ethernet/microsoft/mana/gdma_main.c
@@ -352,11 +352,58 @@ void mana_gd_ring_cq(struct gdma_queue *cq, u8 arm_bit)
 }
 EXPORT_SYMBOL_NS(mana_gd_ring_cq, "NET_MANA");
 
+#define MANA_SERVICE_PERIOD 10
+
+struct mana_serv_work {
+       struct work_struct serv_work;
+       struct pci_dev *pdev;
+};
+
+static void mana_serv_func(struct work_struct *w)
+{
+       struct mana_serv_work *mns_wk;
+       struct pci_bus *bus, *parent;
+       struct pci_dev *pdev;
+
+       mns_wk = container_of(w, struct mana_serv_work, serv_work);
+       pdev = mns_wk->pdev;
+
+       pci_lock_rescan_remove();
+
+       if (!pdev)
+               goto out;
+
+       bus = pdev->bus;
+       if (!bus) {
+               dev_err(&pdev->dev, "MANA service: no bus\n");
+               goto out;
+       }
+
+       parent = bus->parent;
+       if (!parent) {
+               dev_err(&pdev->dev, "MANA service: no parent bus\n");
+               goto out;
+       }
+
+       pci_stop_and_remove_bus_device(bus->self);
+
+       msleep(MANA_SERVICE_PERIOD * 1000);
+
+       pci_rescan_bus(parent);
+
+out:
+       pci_unlock_rescan_remove();
+
+       pci_dev_put(pdev);
+       kfree(mns_wk);
+}
+
 static void mana_gd_process_eqe(struct gdma_queue *eq)
 {
        u32 head = eq->head % (eq->queue_size / GDMA_EQE_SIZE);
        struct gdma_context *gc = eq->gdma_dev->gdma_context;
        struct gdma_eqe *eq_eqe_ptr = eq->queue_mem_ptr;
+       struct mana_serv_work *mns_wk;
        union gdma_eqe_info eqe_info;
        enum gdma_eqe_type type;
        struct gdma_event event;
@@ -400,6 +447,26 @@ static void mana_gd_process_eqe(struct gdma_queue *eq)
                eq->eq.callback(eq->eq.context, eq, &event);
                break;
 
+       case GDMA_EQE_HWC_FPGA_RECONFIG:
+               dev_info(gc->dev, "Recv MANA service type:%d\n", type);
+
+               if (gc->in_service) {
+                       dev_info(gc->dev, "Already in service\n");
+                       break;
+               }
+
+               mns_wk = kzalloc(sizeof(*mns_wk), GFP_ATOMIC);
+               if (!mns_wk)
+                       break;
+
+               dev_info(gc->dev, "Start MANA service type:%d\n", type);
+               gc->in_service = true;
+               mns_wk->pdev = to_pci_dev(gc->dev);
+               pci_dev_get(mns_wk->pdev);
+               INIT_WORK(&mns_wk->serv_work, mana_serv_func);
+               schedule_work(&mns_wk->serv_work);
+               break;
+
        default:
                break;
        }
diff --git a/include/net/mana/gdma.h b/include/net/mana/gdma.h
index 228603bf03f2..150ab3610869 100644
--- a/include/net/mana/gdma.h
+++ b/include/net/mana/gdma.h
@@ -58,7 +58,7 @@ enum gdma_eqe_type {
        GDMA_EQE_HWC_INIT_EQ_ID_DB      = 129,
        GDMA_EQE_HWC_INIT_DATA          = 130,
        GDMA_EQE_HWC_INIT_DONE          = 131,
-       GDMA_EQE_HWC_SOC_RECONFIG       = 132,
+       GDMA_EQE_HWC_FPGA_RECONFIG      = 132,
        GDMA_EQE_HWC_SOC_RECONFIG_DATA  = 133,
        GDMA_EQE_RNIC_QP_FATAL          = 176,
 };
@@ -388,6 +388,8 @@ struct gdma_context {
        u32                     test_event_eq_id;
 
        bool                    is_pf;
+       bool                    in_service;
+
        phys_addr_t             bar0_pa;
        void __iomem            *bar0_va;
        void __iomem            *shm_base;
@@ -558,12 +560,16 @@ enum {
 /* Driver can handle holes (zeros) in the device list */
 #define GDMA_DRV_CAP_FLAG_1_DEV_LIST_HOLES_SUP BIT(11)
 
+/* Driver can self reset on FPGA Reconfig EQE notification */
+#define GDMA_DRV_CAP_FLAG_1_HANDLE_RECONFIG_EQE BIT(17)
+
 #define GDMA_DRV_CAP_FLAGS1 \
        (GDMA_DRV_CAP_FLAG_1_EQ_SHARING_MULTI_VPORT | \
         GDMA_DRV_CAP_FLAG_1_NAPI_WKDONE_FIX | \
         GDMA_DRV_CAP_FLAG_1_HWC_TIMEOUT_RECONFIG | \
         GDMA_DRV_CAP_FLAG_1_VARIABLE_INDIRECTION_TABLE_SUPPORT | \
-        GDMA_DRV_CAP_FLAG_1_DEV_LIST_HOLES_SUP)
+        GDMA_DRV_CAP_FLAG_1_DEV_LIST_HOLES_SUP | \
+        GDMA_DRV_CAP_FLAG_1_HANDLE_RECONFIG_EQE)
 
 #define GDMA_DRV_CAP_FLAGS2 0
 
-- 
2.34.1


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