powerpc/eeh: pseries platform EEH operations

There're 4 EEH operations that are covered by the dedicated RTAS
call <ibm,set-eeh-option>: enable or disable EEH, enable MMIO and
enable DMA. At early stage of system boot, the EEH would be tried
to enable on PCI device related device node. MMIO and DMA for
particular PE should be enabled when doing recovery on EEH errors
so that the PE could function properly again.

The patch implements it and abstract that through struct
eeh_ops::set_eeh. It would be help for EEH to support multiple
platforms in future.

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

arch/powerpc/include/asm/eeh.h

@@ -38,6 +38,10 @@ struct device_node;
  * platform should register its own EEH operation callback
  * functions before any EEH further operations.
  */
+#define EEH_OPT_DISABLE		0	/* EEH disable	*/
+#define EEH_OPT_ENABLE		1	/* EEH enable	*/
+#define EEH_OPT_THAW_MMIO	2	/* MMIO enable	*/
+#define EEH_OPT_THAW_DMA	3	/* DMA enable	*/
 struct eeh_ops {
 	char *name;
 	int (*init)(void);

arch/powerpc/include/asm/ppc-pci.h

@@ -56,8 +56,6 @@ struct pci_dev *pci_get_device_by_addr(unsigned long addr);
 #define EEH_LOG_TEMP_FAILURE 1
 #define EEH_LOG_PERM_FAILURE 2
 void eeh_slot_error_detail (struct pci_dn *pdn, int severity);
-#define EEH_THAW_MMIO 2
-#define EEH_THAW_DMA  3
 int eeh_pci_enable(struct pci_dn *pdn, int function);
 int eeh_reset_pe(struct pci_dn *);
 int eeh_wait_for_slot_status(struct pci_dn *pdn, int max_wait_msecs);

arch/powerpc/platforms/pseries/eeh.c

@@ -87,7 +87,6 @@
 #define PCI_BUS_RESET_WAIT_MSEC (60*1000)
 
 /* RTAS tokens */
-static int ibm_set_eeh_option;
 static int ibm_set_slot_reset;
 static int ibm_read_slot_reset_state;
 static int ibm_read_slot_reset_state2;
@@ -283,7 +282,7 @@ void eeh_slot_error_detail(struct pci_dn *pdn, int severity)
 	size_t loglen = 0;
 	pci_regs_buf[0] = 0;
 
-	eeh_pci_enable(pdn, EEH_THAW_MMIO);
+	eeh_pci_enable(pdn, EEH_OPT_THAW_MMIO);
 	eeh_configure_bridge(pdn);
 	eeh_restore_bars(pdn);
 	loglen = eeh_gather_pci_data(pdn, pci_regs_buf, EEH_PCI_REGS_LOG_LEN);
@@ -698,26 +697,15 @@ EXPORT_SYMBOL(eeh_check_failure);
  */
 int eeh_pci_enable(struct pci_dn *pdn, int function)
 {
-	int config_addr;
 	int rc;
 
-	/* Use PE configuration address, if present */
-	config_addr = pdn->eeh_config_addr;
-	if (pdn->eeh_pe_config_addr)
-		config_addr = pdn->eeh_pe_config_addr;
-
-	rc = rtas_call(ibm_set_eeh_option, 4, 1, NULL,
-	               config_addr,
-	               BUID_HI(pdn->phb->buid),
-	               BUID_LO(pdn->phb->buid),
-		            function);
-
+	rc = eeh_ops->set_option(pdn->node, function);
 	if (rc)
 		printk(KERN_WARNING "EEH: Unexpected state change %d, err=%d dn=%s\n",
 		        function, rc, pdn->node->full_name);
 
 	rc = eeh_wait_for_slot_status(pdn, PCI_BUS_RESET_WAIT_MSEC);
-	if ((rc == 4) && (function == EEH_THAW_MMIO))
+	if ((rc == 4) && (function == EEH_OPT_THAW_MMIO))
 		return 0;
 
 	return rc;
@@ -1158,9 +1146,7 @@ static void *eeh_early_enable(struct device_node *dn, void *data)
 	if (regs) {
 		/* First register entry is addr (00BBSS00)  */
 		/* Try to enable eeh */
-		ret = rtas_call(ibm_set_eeh_option, 4, 1, NULL,
-		                regs[0], info->buid_hi, info->buid_lo,
-		                EEH_ENABLE);
+		ret = eeh_ops->set_option(dn, EEH_OPT_ENABLE);
 
 		enable = 0;
 		if (ret == 0) {
@@ -1299,7 +1285,6 @@ void __init eeh_init(void)
 	if (np == NULL)
 		return;
 
-	ibm_set_eeh_option = rtas_token("ibm,set-eeh-option");
 	ibm_set_slot_reset = rtas_token("ibm,set-slot-reset");
 	ibm_read_slot_reset_state2 = rtas_token("ibm,read-slot-reset-state2");
 	ibm_read_slot_reset_state = rtas_token("ibm,read-slot-reset-state");
@@ -1309,9 +1294,6 @@ void __init eeh_init(void)
 	ibm_configure_bridge = rtas_token("ibm,configure-bridge");
 	ibm_configure_pe = rtas_token("ibm,configure-pe");
 
-	if (ibm_set_eeh_option == RTAS_UNKNOWN_SERVICE)
-		return;
-
 	eeh_error_buf_size = rtas_token("rtas-error-log-max");
 	if (eeh_error_buf_size == RTAS_UNKNOWN_SERVICE) {
 		eeh_error_buf_size = 1024;

arch/powerpc/platforms/pseries/eeh_driver.c

@@ -422,7 +422,7 @@ struct pci_dn * handle_eeh_events (struct eeh_event *event)
 
 	/* If all devices reported they can proceed, then re-enable MMIO */
 	if (result == PCI_ERS_RESULT_CAN_RECOVER) {
-		rc = eeh_pci_enable(frozen_pdn, EEH_THAW_MMIO);
+		rc = eeh_pci_enable(frozen_pdn, EEH_OPT_THAW_MMIO);
 
 		if (rc < 0)
 			goto hard_fail;
@@ -436,7 +436,7 @@ struct pci_dn * handle_eeh_events (struct eeh_event *event)
 
 	/* If all devices reported they can proceed, then re-enable DMA */
 	if (result == PCI_ERS_RESULT_CAN_RECOVER) {
-		rc = eeh_pci_enable(frozen_pdn, EEH_THAW_DMA);
+		rc = eeh_pci_enable(frozen_pdn, EEH_OPT_THAW_DMA);
 
 		if (rc < 0)
 			goto hard_fail;

arch/powerpc/platforms/pseries/eeh_pseries.c

@@ -121,7 +121,44 @@ static int pseries_eeh_init(void)
  */
 static int pseries_eeh_set_option(struct device_node *dn, int option)
 {
-	return 0;
+	int ret = 0;
+	struct pci_dn *pdn;
+	const u32 *reg;
+	int config_addr;
+
+	pdn = PCI_DN(dn);
+
+	/*
+	 * When we're enabling or disabling EEH functioality on
+	 * the particular PE, the PE config address is possibly
+	 * unavailable. Therefore, we have to figure it out from
+	 * the FDT node.
+	 */
+	switch (option) {
+	case EEH_OPT_DISABLE:
+	case EEH_OPT_ENABLE:
+		reg = of_get_property(dn, "reg", NULL);
+		config_addr = reg[0];
+		break;
+
+	case EEH_OPT_THAW_MMIO:
+	case EEH_OPT_THAW_DMA:
+		config_addr = pdn->eeh_config_addr;
+		if (pdn->eeh_pe_config_addr)
+			config_addr = pdn->eeh_pe_config_addr;
+		break;
+
+	default:
+		pr_err("%s: Invalid option %d\n",
+			__func__, option);
+		return -EINVAL;
+	}
+
+	ret = rtas_call(ibm_set_eeh_option, 4, 1, NULL,
+			config_addr, BUID_HI(pdn->phb->buid),
+			BUID_LO(pdn->phb->buid), option);
+
+	return ret;
 }
 
 /**