GenWQE: Add sysfs interface for bitstream reload

[mirror_ubuntu-bionic-kernel.git] / drivers / misc / genwqe / card_base.c

diff --git a/drivers/misc/genwqe/card_base.c b/drivers/misc/genwqe/card_base.c
index 74d51c9bb85870df4ace01ac4d4173531aae5984..e6cc3e1e73261c302b575b0eb5e3f0d569926b89 100644 (file)
--- a/drivers/misc/genwqe/card_base.c
+++ b/drivers/misc/genwqe/card_base.c
@@ -760,6 +760,89 @@ static u64 genwqe_fir_checking(struct genwqe_dev *cd)
        return IO_ILLEGAL_VALUE;
 }
 
+/**
+ * genwqe_pci_fundamental_reset() - trigger a PCIe fundamental reset on the slot
+ *
+ * Note: pci_set_pcie_reset_state() is not implemented on all archs, so this
+ * reset method will not work in all cases.
+ *
+ * Return: 0 on success or error code from pci_set_pcie_reset_state()
+ */
+static int genwqe_pci_fundamental_reset(struct pci_dev *pci_dev)
+{
+       int rc;
+
+       /*
+        * lock pci config space access from userspace,
+        * save state and issue PCIe fundamental reset
+        */
+       pci_cfg_access_lock(pci_dev);
+       pci_save_state(pci_dev);
+       rc = pci_set_pcie_reset_state(pci_dev, pcie_warm_reset);
+       if (!rc) {
+               /* keep PCIe reset asserted for 250ms */
+               msleep(250);
+               pci_set_pcie_reset_state(pci_dev, pcie_deassert_reset);
+               /* Wait for 2s to reload flash and train the link */
+               msleep(2000);
+       }
+       pci_restore_state(pci_dev);
+       pci_cfg_access_unlock(pci_dev);
+       return rc;
+}
+
+/*
+ * genwqe_reload_bistream() - reload card bitstream
+ *
+ * Set the appropriate register and call fundamental reset to reaload the card
+ * bitstream.
+ *
+ * Return: 0 on success, error code otherwise
+ */
+static int genwqe_reload_bistream(struct genwqe_dev *cd)
+{
+       struct pci_dev *pci_dev = cd->pci_dev;
+       int rc;
+
+       dev_info(&pci_dev->dev,
+                "[%s] resetting card for bitstream reload\n",
+                __func__);
+
+       genwqe_stop(cd);
+
+       /*
+        * Cause a CPLD reprogram with the 'next_bitstream'
+        * partition on PCIe hot or fundamental reset
+        */
+       __genwqe_writeq(cd, IO_SLC_CFGREG_SOFTRESET,
+                       (cd->softreset & 0xcull) | 0x70ull);
+
+       rc = genwqe_pci_fundamental_reset(pci_dev);
+       if (rc) {
+               /*
+                * A fundamental reset failure can be caused
+                * by lack of support on the arch, so we just
+                * log the error and try to start the card
+                * again.
+                */
+               dev_err(&pci_dev->dev,
+                       "[%s] err: failed to reset card for bitstream reload\n",
+                       __func__);
+       }
+
+       rc = genwqe_start(cd);
+       if (rc) {
+               dev_err(&pci_dev->dev,
+                       "[%s] err: cannot start card services! (err=%d)\n",
+                       __func__, rc);
+               return rc;
+       }
+       dev_info(&pci_dev->dev,
+                "[%s] card reloaded\n", __func__);
+       return 0;
+}
+
+
 /**
  * genwqe_health_thread() - Health checking thread
  *
@@ -846,6 +929,13 @@ static int genwqe_health_thread(void *data)
                        }
                }
 
+               if (cd->card_state == GENWQE_CARD_RELOAD_BITSTREAM) {
+                       /* Userspace requested card bitstream reload */
+                       rc = genwqe_reload_bistream(cd);
+                       if (rc)
+                               goto fatal_error;
+               }
+
                cd->last_gfir = gfir;
                cond_resched();
        }