powerpc/eeh: Call opal_pci_reinit() on powernv for restoring config space

The patch implements the EEH operation backend restore_config()
for PowerNV platform. That relies on OPAL API opal_pci_reinit()
where we reinitialize the error reporting properly after PE or
PHB reset.

Signed-off-by: Gavin Shan <shangw@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

arch/powerpc/include/asm/opal.h

@@ -344,12 +344,16 @@ enum OpalMveEnableAction {
 	OPAL_ENABLE_MVE = 1
 };
 
-enum OpalPciResetAndReinitScope {
+enum OpalPciResetScope {
 	OPAL_PHB_COMPLETE = 1, OPAL_PCI_LINK = 2, OPAL_PHB_ERROR = 3,
 	OPAL_PCI_HOT_RESET = 4, OPAL_PCI_FUNDAMENTAL_RESET = 5,
 	OPAL_PCI_IODA_TABLE_RESET = 6,
 };
 
+enum OpalPciReinitScope {
+	OPAL_REINIT_PCI_DEV = 1000
+};
+
 enum OpalPciResetState {
 	OPAL_DEASSERT_RESET = 0,
 	OPAL_ASSERT_RESET = 1
@@ -801,7 +805,7 @@ int64_t opal_pci_get_phb_diag_data(uint64_t phb_id, void *diag_buffer,
 int64_t opal_pci_get_phb_diag_data2(uint64_t phb_id, void *diag_buffer,
 				    uint64_t diag_buffer_len);
 int64_t opal_pci_fence_phb(uint64_t phb_id);
-int64_t opal_pci_reinit(uint64_t phb_id, uint8_t reinit_scope);
+int64_t opal_pci_reinit(uint64_t phb_id, uint64_t reinit_scope, uint64_t data);
 int64_t opal_pci_mask_pe_error(uint64_t phb_id, uint16_t pe_number, uint8_t error_type, uint8_t mask_action);
 int64_t opal_set_slot_led_status(uint64_t phb_id, uint64_t slot_id, uint8_t led_type, uint8_t led_action);
 int64_t opal_get_epow_status(__be64 *status);

arch/powerpc/platforms/powernv/eeh-powernv.c

@@ -344,6 +344,27 @@ static int powernv_eeh_next_error(struct eeh_pe **pe)
 	return -EEXIST;
 }
 
+static int powernv_eeh_restore_config(struct device_node *dn)
+{
+	struct eeh_dev *edev = of_node_to_eeh_dev(dn);
+	struct pnv_phb *phb;
+	s64 ret;
+
+	if (!edev)
+		return -EEXIST;
+
+	phb = edev->phb->private_data;
+	ret = opal_pci_reinit(phb->opal_id,
+			      OPAL_REINIT_PCI_DEV, edev->config_addr);
+	if (ret) {
+		pr_warn("%s: Can't reinit PCI dev 0x%x (%lld)\n",
+			__func__, edev->config_addr, ret);
+		return -EIO;
+	}
+
+	return 0;
+}
+
 static struct eeh_ops powernv_eeh_ops = {
 	.name                   = "powernv",
 	.init                   = powernv_eeh_init,
@@ -360,7 +381,7 @@ static struct eeh_ops powernv_eeh_ops = {
 	.read_config            = pnv_pci_cfg_read,
 	.write_config           = pnv_pci_cfg_write,
 	.next_error		= powernv_eeh_next_error,
-	.restore_config		= NULL
+	.restore_config		= powernv_eeh_restore_config
 };
 
 /**