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>

1 files changed, 38 insertions, 1 deletions

diff --git a/arch/powerpc/platforms/pseries/eeh_pseries.c b/arch/powerpc/platforms/pseries/eeh_pseries.c
index 1a9410a2d452..c48a9e6ecdd6 100644
--- a/arch/powerpc/platforms/pseries/eeh_pseries.c
+++ b/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;
 }
 
 /**