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-rw-r--r--drivers/ntb/hw/amd/ntb_hw_amd.c57
-rw-r--r--drivers/ntb/hw/amd/ntb_hw_amd.h1
2 files changed, 56 insertions, 2 deletions
diff --git a/drivers/ntb/hw/amd/ntb_hw_amd.c b/drivers/ntb/hw/amd/ntb_hw_amd.c
index 04be1482037b..c6cea0005553 100644
--- a/drivers/ntb/hw/amd/ntb_hw_amd.c
+++ b/drivers/ntb/hw/amd/ntb_hw_amd.c
@@ -647,6 +647,36 @@ static void amd_handle_event(struct amd_ntb_dev *ndev, int vec)
writel(status, mmio + AMD_INTSTAT_OFFSET);
}
+static void amd_handle_db_event(struct amd_ntb_dev *ndev, int vec)
+{
+ struct device *dev = &ndev->ntb.pdev->dev;
+ u64 status;
+
+ status = amd_ntb_db_read(&ndev->ntb);
+
+ dev_dbg(dev, "status = 0x%llx and vec = %d\n", status, vec);
+
+ /*
+ * Since we had reserved highest order bit of DB for signaling peer of
+ * a special event, this is the only status bit we should be concerned
+ * here now.
+ */
+ if (status & BIT(ndev->db_last_bit)) {
+ ntb_db_clear(&ndev->ntb, BIT(ndev->db_last_bit));
+ /* send link down event notification */
+ ntb_link_event(&ndev->ntb);
+
+ /*
+ * If we are here, that means the peer has signalled a special
+ * event which notifies that the peer driver has been
+ * un-loaded for some reason. Since there is a chance that the
+ * peer will load its driver again sometime, we schedule link
+ * polling routine.
+ */
+ schedule_delayed_work(&ndev->hb_timer, AMD_LINK_HB_TIMEOUT);
+ }
+}
+
static irqreturn_t ndev_interrupt(struct amd_ntb_dev *ndev, int vec)
{
dev_dbg(&ndev->ntb.pdev->dev, "vec %d\n", vec);
@@ -654,8 +684,10 @@ static irqreturn_t ndev_interrupt(struct amd_ntb_dev *ndev, int vec)
if (vec > (AMD_DB_CNT - 1) || (ndev->msix_vec_count == 1))
amd_handle_event(ndev, vec);
- if (vec < AMD_DB_CNT)
+ if (vec < AMD_DB_CNT) {
+ amd_handle_db_event(ndev, vec);
ntb_db_event(&ndev->ntb, vec);
+ }
return IRQ_HANDLED;
}
@@ -1097,6 +1129,21 @@ static int amd_init_dev(struct amd_ntb_dev *ndev)
}
ndev->db_valid_mask = BIT_ULL(ndev->db_count) - 1;
+ /*
+ * We reserve the highest order bit of the DB register which will
+ * be used to notify peer when the driver on this side is being
+ * un-loaded.
+ */
+ ndev->db_last_bit =
+ find_last_bit((unsigned long *)&ndev->db_valid_mask,
+ hweight64(ndev->db_valid_mask));
+ writew((u16)~BIT(ndev->db_last_bit), mmio + AMD_DBMASK_OFFSET);
+ /*
+ * Since now there is one less bit to account for, the DB count
+ * and DB mask should be adjusted accordingly.
+ */
+ ndev->db_count -= 1;
+ ndev->db_valid_mask = BIT_ULL(ndev->db_count) - 1;
/* Enable Link-Up and Link-Down event interrupts */
ndev->int_mask &= ~(AMD_LINK_UP_EVENT | AMD_LINK_DOWN_EVENT);
@@ -1235,9 +1282,15 @@ static void amd_ntb_pci_remove(struct pci_dev *pdev)
{
struct amd_ntb_dev *ndev = pci_get_drvdata(pdev);
+ /*
+ * Clear the READY bit in SIDEINFO register before sending DB event
+ * to the peer. This will make sure that when the peer handles the
+ * DB event, it correctly reads this bit as being 0.
+ */
+ amd_deinit_side_info(ndev);
+ ntb_peer_db_set(&ndev->ntb, BIT_ULL(ndev->db_last_bit));
ntb_unregister_device(&ndev->ntb);
ndev_deinit_debugfs(ndev);
- amd_deinit_side_info(ndev);
amd_deinit_dev(ndev);
amd_ntb_deinit_pci(ndev);
kfree(ndev);
diff --git a/drivers/ntb/hw/amd/ntb_hw_amd.h b/drivers/ntb/hw/amd/ntb_hw_amd.h
index 73959c0b9972..5f337b1572a0 100644
--- a/drivers/ntb/hw/amd/ntb_hw_amd.h
+++ b/drivers/ntb/hw/amd/ntb_hw_amd.h
@@ -193,6 +193,7 @@ struct amd_ntb_dev {
u64 db_valid_mask;
u64 db_mask;
+ u64 db_last_bit;
u32 int_mask;
struct msix_entry *msix;