From: Wen Xiong <wenxi...@linux.vnet.ibm.com>
Several device drivers hit EEH(Extended Error handling) when triggering
kdump on Pseries PowerVM. This patch implemented a reset of the PHBs
in pci general code when triggering kdump. PHB reset stop all PCI
transactions from normal kernel. We have tested the patch in several
enviroments:
- direct slot adapters
- adapters under the switch
- a VF adapter in PowerVM
- a VF adapter/adapter in KVM guest.
Signed-off-by: Wen Xiong <wenxi...@linux.vnet.ibm.com>
---
arch/powerpc/platforms/pseries/pci.c | 152 +++++++++++++++++++++++++++
1 file changed, 152 insertions(+)
diff --git a/arch/powerpc/platforms/pseries/pci.c
b/arch/powerpc/platforms/pseries/pci.c
index 911534b89c85..cb7e4276cf04 100644
--- a/arch/powerpc/platforms/pseries/pci.c
+++ b/arch/powerpc/platforms/pseries/pci.c
@@ -11,6 +11,8 @@
#include <linux/kernel.h>
#include <linux/pci.h>
#include <linux/string.h>
+#include <linux/crash_dump.h>
+#include <linux/delay.h>
#include <asm/eeh.h>
#include <asm/pci-bridge.h>
@@ -354,3 +356,153 @@ int pseries_root_bridge_prepare(struct pci_host_bridge
*bridge)
return 0;
}
+
+/**
+ * pseries_get_pdn_addr - Retrieve PHB address
+ * @pe: EEH PE
+ *
+ * Retrieve the assocated PHB address. Actually, there're 2 RTAS
+ * function calls dedicated for the purpose. We need implement
+ * it through the new function and then the old one. Besides,
+ * you should make sure the config address is figured out from
+ * FDT node before calling the function.
+ *
+ */
+static int pseries_get_pdn_addr(struct pci_controller *phb)
+{
+ int ret = -1;
+ int rets[3];
+ int ibm_get_config_addr_info;
+ int ibm_get_config_addr_info2;
+ int config_addr = 0;
+ struct pci_dn *root_pdn, *pdn;
+
+ ibm_get_config_addr_info2 = rtas_token("ibm,get-config-addr-info2");
+ ibm_get_config_addr_info = rtas_token("ibm,get-config-addr-info");
+
+ root_pdn = PCI_DN(phb->dn);
+ pdn = list_first_entry(&root_pdn->child_list, struct pci_dn, list);
+ config_addr = (pdn->busno << 16) | (pdn->devfn << 8);
+
+ if (ibm_get_config_addr_info2 != RTAS_UNKNOWN_SERVICE) {
+ /*
+ * First of all, we need to make sure there has one PE
+ * associated with the device. If option is 1, it
+ * queries if config address is supported in a PE or not.
+ * If option is 0, it returns PE config address or config
+ * address for the PE primary bus.
+ */
+ ret = rtas_call(ibm_get_config_addr_info2, 4, 2, rets,
+ config_addr, BUID_HI(pdn->phb->buid),
+ BUID_LO(pdn->phb->buid), 1);
+ if (ret || (rets[0] == 0)) {
+ pr_warn("%s: Failed to get address for PHB#%x-PE#
option=%d config_addr=%x\n",
+ __func__, pdn->phb->global_number, 1, rets[0]);
+ return -1;
+ }
+
+ /* Retrieve the associated PE config address */
+ ret = rtas_call(ibm_get_config_addr_info2, 4, 2, rets,
+ config_addr, BUID_HI(pdn->phb->buid),
+ BUID_LO(pdn->phb->buid), 0);
+ if (ret) {
+ pr_warn("%s: Failed to get address for PHB#%x-PE#
option=%d config_addr=%x\n",
+ __func__, pdn->phb->global_number, 0, rets[0]);
+ return -1;
+ }
+ return rets[0];
+ }
+
+ if (ibm_get_config_addr_info != RTAS_UNKNOWN_SERVICE) {
+ ret = rtas_call(ibm_get_config_addr_info, 4, 2, rets,
+ config_addr, BUID_HI(pdn->phb->buid),
+ BUID_LO(pdn->phb->buid), 0);
+ if (ret || rets[0]) {
+ pr_warn("%s: Failed to get address for PHB#%x-PE#
config_addr=%x\n",
+ __func__, pdn->phb->global_number, rets[0]);
+ return -1;
+ }
+ return rets[0];
+ }
+
+ return ret;
+}
+
+static int __init pseries_phb_reset(void)
+{
+ struct pci_controller *phb;
+ int config_addr;
+ int ibm_set_slot_reset;
+ int ibm_configure_pe;
+ int ret;
+
+ if (is_kdump_kernel() || reset_devices) {
+ pr_info("Issue PHB reset ...\n");
+ ibm_set_slot_reset = rtas_token("ibm,set-slot-reset");
+ ibm_configure_pe = rtas_token("ibm,configure-pe");
+
+ if (ibm_set_slot_reset == RTAS_UNKNOWN_SERVICE ||
+ ibm_configure_pe == RTAS_UNKNOWN_SERVICE) {
+ pr_info("%s: EEH functionality not supported\n",
+ __func__);
+ }
+
+ list_for_each_entry(phb, &hose_list, list_node) {
+ config_addr = pseries_get_pdn_addr(phb);
+ if (config_addr == -1)
+ continue;
+
+ ret = rtas_call(ibm_set_slot_reset, 4, 1, NULL,
+ config_addr, BUID_HI(phb->buid),
+ BUID_LO(phb->buid), EEH_RESET_FUNDAMENTAL);
+
+ /* If fundamental-reset not supported, try hot-reset */
+ if (ret == -8)
+ ret = rtas_call(ibm_set_slot_reset, 4, 1, NULL,
+ config_addr, BUID_HI(phb->buid),
+ BUID_LO(phb->buid), EEH_RESET_HOT);
+
+ if (ret) {
+ pr_err("%s: PHB#%x-PE# failed with rtas_call
activate reset=%d\n",
+ __func__, phb->global_number, ret);
+ continue;
+ }
+ }
+ msleep(EEH_PE_RST_SETTLE_TIME);
+
+ list_for_each_entry(phb, &hose_list, list_node) {
+ config_addr = pseries_get_pdn_addr(phb);
+ if (config_addr == -1)
+ continue;
+
+ ret = rtas_call(ibm_set_slot_reset, 4, 1, NULL,
+ config_addr, BUID_HI(phb->buid),
+ BUID_LO(phb->buid), EEH_RESET_DEACTIVATE);
+ if (ret) {
+ pr_err("%s: PHB#%x-PE# failed with rtas_call
deactive reset=%d\n",
+ __func__, phb->global_number, ret);
+ continue;
+ }
+ }
+ msleep(EEH_PE_RST_SETTLE_TIME);
+
+ list_for_each_entry(phb, &hose_list, list_node) {
+ config_addr = pseries_get_pdn_addr(phb);
+ if (config_addr == -1)
+ continue;
+
+ ret = rtas_call(ibm_configure_pe, 3, 1, NULL,
+ config_addr, BUID_HI(phb->buid),
+ BUID_LO(phb->buid));
+ if (ret) {
+ pr_err("%s: PHB#%x-PE# failed with rtas_call
configure_pe =%d\n",
+ __func__, phb->global_number, ret);
+ continue;
+ }
+ }
+ }
+
+ return 0;
+}
+machine_postcore_initcall(pseries, pseries_phb_reset);
+
--
2.18.1
