From: Wen Xiong wenxiong@linux.vnet.ibm.com
[ Upstream commit 5a090f7c363fdc09b99222eae679506a58e7cc68 ]
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 wenxiong@linux.vnet.ibm.com [mpe: Fix broken whitespace, subject & SOB formatting] Signed-off-by: Michael Ellerman mpe@ellerman.id.au Link: https://lore.kernel.org/r/1594651173-32166-1-git-send-email-wenxiong@linux.v... Stable-dep-of: 9aafbfa5f57a ("powerpc/pseries/eeh: use correct API for error log size") Signed-off-by: Sasha Levin sashal@kernel.org --- arch/powerpc/platforms/pseries/eeh_pseries.c | 232 ++++++++++++++----- 1 file changed, 169 insertions(+), 63 deletions(-)
diff --git a/arch/powerpc/platforms/pseries/eeh_pseries.c b/arch/powerpc/platforms/pseries/eeh_pseries.c index 0fc93f7e167d..560d7401496c 100644 --- a/arch/powerpc/platforms/pseries/eeh_pseries.c +++ b/arch/powerpc/platforms/pseries/eeh_pseries.c @@ -37,6 +37,7 @@ #include <linux/sched.h> #include <linux/seq_file.h> #include <linux/spinlock.h> +#include <linux/crash_dump.h>
#include <asm/eeh.h> #include <asm/eeh_event.h> @@ -94,6 +95,152 @@ void pseries_pcibios_bus_add_device(struct pci_dev *pdev) eeh_sysfs_add_device(pdev); }
+ +/** + * pseries_eeh_get_config_addr - Retrieve config address + * + * Retrieve the assocated config 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. + * + * It's notable that zero'ed return value means invalid PE config + * address. + */ +static int pseries_eeh_get_config_addr(struct pci_controller *phb, int config_addr) +{ + int ret = 0; + int rets[3]; + + 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. Otherwise, PE address is + * meaningless. + */ + ret = rtas_call(ibm_get_config_addr_info2, 4, 2, rets, + config_addr, BUID_HI(phb->buid), + BUID_LO(phb->buid), 1); + if (ret || (rets[0] == 0)) + return 0; + + /* Retrieve the associated PE config address */ + ret = rtas_call(ibm_get_config_addr_info2, 4, 2, rets, + config_addr, BUID_HI(phb->buid), + BUID_LO(phb->buid), 0); + if (ret) { + pr_warn("%s: Failed to get address for PHB#%x-PE#%x\n", + __func__, phb->global_number, config_addr); + return 0; + } + + 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(phb->buid), + BUID_LO(phb->buid), 0); + if (ret) { + pr_warn("%s: Failed to get address for PHB#%x-PE#%x\n", + __func__, phb->global_number, config_addr); + return 0; + } + + return rets[0]; + } + + return ret; +} + +/** + * pseries_eeh_phb_reset - Reset the specified PHB + * @phb: PCI controller + * @config_adddr: the associated config address + * @option: reset option + * + * Reset the specified PHB/PE + */ +static int pseries_eeh_phb_reset(struct pci_controller *phb, int config_addr, int option) +{ + int ret; + + /* Reset PE through RTAS call */ + ret = rtas_call(ibm_set_slot_reset, 4, 1, NULL, + config_addr, BUID_HI(phb->buid), + BUID_LO(phb->buid), option); + + /* If fundamental-reset not supported, try hot-reset */ + if (option == EEH_RESET_FUNDAMENTAL && + ret == -8) { + option = EEH_RESET_HOT; + ret = rtas_call(ibm_set_slot_reset, 4, 1, NULL, + config_addr, BUID_HI(phb->buid), + BUID_LO(phb->buid), option); + } + + /* We need reset hold or settlement delay */ + if (option == EEH_RESET_FUNDAMENTAL || + option == EEH_RESET_HOT) + msleep(EEH_PE_RST_HOLD_TIME); + else + msleep(EEH_PE_RST_SETTLE_TIME); + + return ret; +} + +/** + * pseries_eeh_phb_configure_bridge - Configure PCI bridges in the indicated PE + * @phb: PCI controller + * @config_adddr: the associated config address + * + * The function will be called to reconfigure the bridges included + * in the specified PE so that the mulfunctional PE would be recovered + * again. + */ +static int pseries_eeh_phb_configure_bridge(struct pci_controller *phb, int config_addr) +{ + int ret; + /* Waiting 0.2s maximum before skipping configuration */ + int max_wait = 200; + + while (max_wait > 0) { + ret = rtas_call(ibm_configure_pe, 3, 1, NULL, + config_addr, BUID_HI(phb->buid), + BUID_LO(phb->buid)); + + if (!ret) + return ret; + if (ret < 0) + break; + + /* + * If RTAS returns a delay value that's above 100ms, cut it + * down to 100ms in case firmware made a mistake. For more + * on how these delay values work see rtas_busy_delay_time + */ + if (ret > RTAS_EXTENDED_DELAY_MIN+2 && + ret <= RTAS_EXTENDED_DELAY_MAX) + ret = RTAS_EXTENDED_DELAY_MIN+2; + + max_wait -= rtas_busy_delay_time(ret); + + if (max_wait < 0) + break; + + rtas_busy_delay(ret); + } + + pr_warn("%s: Unable to configure bridge PHB#%x-PE#%x (%d)\n", + __func__, phb->global_number, config_addr, ret); + /* PAPR defines -3 as "Parameter Error" for this function: */ + if (ret == -3) + return -EINVAL; + else + return -EIO; +} + /* * Buffer for reporting slot-error-detail rtas calls. Its here * in BSS, and not dynamically alloced, so that it ends up in @@ -110,6 +257,10 @@ static int eeh_error_buf_size; */ static int pseries_eeh_init(void) { + struct pci_controller *phb; + struct pci_dn *pdn; + int addr, config_addr; + /* figure out EEH RTAS function call tokens */ ibm_set_eeh_option = rtas_token("ibm,set-eeh-option"); ibm_set_slot_reset = rtas_token("ibm,set-slot-reset"); @@ -162,6 +313,22 @@ static int pseries_eeh_init(void) /* Set EEH machine dependent code */ ppc_md.pcibios_bus_add_device = pseries_pcibios_bus_add_device;
+ if (is_kdump_kernel() || reset_devices) { + pr_info("Issue PHB reset ...\n"); + list_for_each_entry(phb, &hose_list, list_node) { + pdn = list_first_entry(&PCI_DN(phb->dn)->child_list, struct pci_dn, list); + addr = (pdn->busno << 16) | (pdn->devfn << 8); + config_addr = pseries_eeh_get_config_addr(phb, addr); + /* invalid PE config addr */ + if (config_addr == 0) + continue; + + pseries_eeh_phb_reset(phb, config_addr, EEH_RESET_FUNDAMENTAL); + pseries_eeh_phb_reset(phb, config_addr, EEH_RESET_DEACTIVATE); + pseries_eeh_phb_configure_bridge(phb, config_addr); + } + } + return 0; }
@@ -531,35 +698,13 @@ static int pseries_eeh_get_state(struct eeh_pe *pe, int *state) static int pseries_eeh_reset(struct eeh_pe *pe, int option) { int config_addr; - int ret;
/* Figure out PE address */ config_addr = pe->config_addr; if (pe->addr) config_addr = pe->addr;
- /* Reset PE through RTAS call */ - ret = rtas_call(ibm_set_slot_reset, 4, 1, NULL, - config_addr, BUID_HI(pe->phb->buid), - BUID_LO(pe->phb->buid), option); - - /* If fundamental-reset not supported, try hot-reset */ - if (option == EEH_RESET_FUNDAMENTAL && - ret == -8) { - option = EEH_RESET_HOT; - ret = rtas_call(ibm_set_slot_reset, 4, 1, NULL, - config_addr, BUID_HI(pe->phb->buid), - BUID_LO(pe->phb->buid), option); - } - - /* We need reset hold or settlement delay */ - if (option == EEH_RESET_FUNDAMENTAL || - option == EEH_RESET_HOT) - msleep(EEH_PE_RST_HOLD_TIME); - else - msleep(EEH_PE_RST_SETTLE_TIME); - - return ret; + return pseries_eeh_phb_reset(pe->phb, config_addr, option); }
/** @@ -661,56 +806,17 @@ static int pseries_eeh_get_log(struct eeh_pe *pe, int severity, char *drv_log, u * pseries_eeh_configure_bridge - Configure PCI bridges in the indicated PE * @pe: EEH PE * - * The function will be called to reconfigure the bridges included - * in the specified PE so that the mulfunctional PE would be recovered - * again. */ static int pseries_eeh_configure_bridge(struct eeh_pe *pe) { int config_addr; - int ret; - /* Waiting 0.2s maximum before skipping configuration */ - int max_wait = 200;
/* Figure out the PE address */ config_addr = pe->config_addr; if (pe->addr) config_addr = pe->addr;
- while (max_wait > 0) { - ret = rtas_call(ibm_configure_pe, 3, 1, NULL, - config_addr, BUID_HI(pe->phb->buid), - BUID_LO(pe->phb->buid)); - - if (!ret) - return ret; - if (ret < 0) - break; - - /* - * If RTAS returns a delay value that's above 100ms, cut it - * down to 100ms in case firmware made a mistake. For more - * on how these delay values work see rtas_busy_delay_time - */ - if (ret > RTAS_EXTENDED_DELAY_MIN+2 && - ret <= RTAS_EXTENDED_DELAY_MAX) - ret = RTAS_EXTENDED_DELAY_MIN+2; - - max_wait -= rtas_busy_delay_time(ret); - - if (max_wait < 0) - break; - - rtas_busy_delay(ret); - } - - pr_warn("%s: Unable to configure bridge PHB#%x-PE#%x (%d)\n", - __func__, pe->phb->global_number, pe->addr, ret); - /* PAPR defines -3 as "Parameter Error" for this function: */ - if (ret == -3) - return -EINVAL; - else - return -EIO; + return pseries_eeh_phb_configure_bridge(pe->phb, config_addr); }
/**