From 26833a5029b710b12f00607fa255ce86909836ad Mon Sep 17 00:00:00 2001 From: Gavin Shan Date: Thu, 24 Apr 2014 18:00:23 +1000 Subject: [PATCH] powerpc/eeh: Make the delay for PE reset unified Basically, we have 3 types of resets to fulfil PE reset: fundamental, hot and PHB reset. For the later 2 cases, we need PCI bus reset hold and settlement delay as specified by PCI spec. PowerNV and pSeries platforms are running on top of different firmware and some of the delays have been covered by underly firmware (PowerNV). The patch makes the delays unified to be done in backend, instead of EEH core. Signed-off-by: Gavin Shan Signed-off-by: Benjamin Herrenschmidt --- arch/powerpc/include/asm/eeh.h | 10 ++++++++++ arch/powerpc/kernel/eeh.c | 13 ------------- arch/powerpc/platforms/powernv/eeh-ioda.c | 12 +++++++++++- arch/powerpc/platforms/pseries/eeh_pseries.c | 10 +++++++++- 4 files changed, 30 insertions(+), 15 deletions(-) diff --git a/arch/powerpc/include/asm/eeh.h b/arch/powerpc/include/asm/eeh.h index 2841ecac4c47..b76f58c124ca 100644 --- a/arch/powerpc/include/asm/eeh.h +++ b/arch/powerpc/include/asm/eeh.h @@ -38,6 +38,16 @@ struct device_node; #define EEH_PROBE_MODE_DEV 0x4 /* From PCI device */ #define EEH_PROBE_MODE_DEVTREE 0x8 /* From device tree */ +/* + * Delay for PE reset, all in ms + * + * PCI specification has reset hold time of 100 milliseconds. + * We have 250 milliseconds here. The PCI bus settlement time + * is specified as 1.5 seconds and we have 1.8 seconds. + */ +#define EEH_PE_RST_HOLD_TIME 250 +#define EEH_PE_RST_SETTLE_TIME 1800 + /* * The struct is used to trace PE related EEH functionality. * In theory, there will have one instance of the struct to diff --git a/arch/powerpc/kernel/eeh.c b/arch/powerpc/kernel/eeh.c index 1e409a2ff88b..3764fb788d6c 100644 --- a/arch/powerpc/kernel/eeh.c +++ b/arch/powerpc/kernel/eeh.c @@ -639,20 +639,7 @@ static void eeh_reset_pe_once(struct eeh_pe *pe) else eeh_ops->reset(pe, EEH_RESET_HOT); - /* The PCI bus requires that the reset be held high for at least - * a 100 milliseconds. We wait a bit longer 'just in case'. - */ -#define PCI_BUS_RST_HOLD_TIME_MSEC 250 - msleep(PCI_BUS_RST_HOLD_TIME_MSEC); - eeh_ops->reset(pe, EEH_RESET_DEACTIVATE); - - /* After a PCI slot has been reset, the PCI Express spec requires - * a 1.5 second idle time for the bus to stabilize, before starting - * up traffic. - */ -#define PCI_BUS_SETTLE_TIME_MSEC 1800 - msleep(PCI_BUS_SETTLE_TIME_MSEC); } /** diff --git a/arch/powerpc/platforms/powernv/eeh-ioda.c b/arch/powerpc/platforms/powernv/eeh-ioda.c index 0844e00ccdd8..268cd46af8f1 100644 --- a/arch/powerpc/platforms/powernv/eeh-ioda.c +++ b/arch/powerpc/platforms/powernv/eeh-ioda.c @@ -417,9 +417,13 @@ static int ioda_eeh_phb_reset(struct pci_controller *hose, int option) /* * Poll state of the PHB until the request is done - * successfully. + * successfully. The PHB reset is usually PHB complete + * reset followed by hot reset on root bus. So we also + * need the PCI bus settlement delay. */ rc = ioda_eeh_phb_poll(phb); + if (option == EEH_RESET_DEACTIVATE) + msleep(EEH_PE_RST_SETTLE_TIME); out: if (rc != OPAL_SUCCESS) return -EIO; @@ -457,6 +461,8 @@ static int ioda_eeh_root_reset(struct pci_controller *hose, int option) /* Poll state of the PHB until the request is done */ rc = ioda_eeh_phb_poll(phb); + if (option == EEH_RESET_DEACTIVATE) + msleep(EEH_PE_RST_SETTLE_TIME); out: if (rc != OPAL_SUCCESS) return -EIO; @@ -480,11 +486,15 @@ static int ioda_eeh_bridge_reset(struct pci_dev *dev, int option) eeh_ops->read_config(dn, PCI_BRIDGE_CONTROL, 2, &ctrl); ctrl |= PCI_BRIDGE_CTL_BUS_RESET; eeh_ops->write_config(dn, PCI_BRIDGE_CONTROL, 2, ctrl); + + msleep(EEH_PE_RST_HOLD_TIME); break; case EEH_RESET_DEACTIVATE: eeh_ops->read_config(dn, PCI_BRIDGE_CONTROL, 2, &ctrl); ctrl &= ~PCI_BRIDGE_CTL_BUS_RESET; eeh_ops->write_config(dn, PCI_BRIDGE_CONTROL, 2, ctrl); + + msleep(EEH_PE_RST_SETTLE_TIME); break; } diff --git a/arch/powerpc/platforms/pseries/eeh_pseries.c b/arch/powerpc/platforms/pseries/eeh_pseries.c index 2f1ba64fc831..0bec0c02c5e7 100644 --- a/arch/powerpc/platforms/pseries/eeh_pseries.c +++ b/arch/powerpc/platforms/pseries/eeh_pseries.c @@ -532,11 +532,19 @@ static int pseries_eeh_reset(struct eeh_pe *pe, int 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), EEH_RESET_HOT); + 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; } -- 2.30.2