From 6654c9368a6ff75a36230d8eb94676da1d01f5ae Mon Sep 17 00:00:00 2001 From: Russell Currey Date: Thu, 17 Nov 2016 16:07:47 +1100 Subject: [PATCH] powerpc/eeh: Refactor EEH PE reset functions eeh_pe_reset and eeh_reset_pe are two different functions in the same file which do mostly the same thing. Not only is this confusing, but potentially causes disrepancies in functionality, notably eeh_reset_pe as it does not check return values for failure. Refactor this into the following: - eeh_pe_reset(): stays as is, performs a single operation, exported - eeh_pe_reset_full(): new, full reset process that calls eeh_pe_reset() - eeh_reset_pe(): removed and replaced by eeh_pe_reset_full() - eeh_reset_pe_once(): removed Signed-off-by: Russell Currey Signed-off-by: Michael Ellerman --- arch/powerpc/include/asm/ppc-pci.h | 2 +- arch/powerpc/kernel/eeh.c | 78 ++++++++++++++---------------- arch/powerpc/kernel/eeh_driver.c | 4 +- 3 files changed, 38 insertions(+), 46 deletions(-) diff --git a/arch/powerpc/include/asm/ppc-pci.h b/arch/powerpc/include/asm/ppc-pci.h index 0f73de069f19..726288048652 100644 --- a/arch/powerpc/include/asm/ppc-pci.h +++ b/arch/powerpc/include/asm/ppc-pci.h @@ -53,7 +53,7 @@ void eeh_addr_cache_rmv_dev(struct pci_dev *dev); struct eeh_dev *eeh_addr_cache_get_dev(unsigned long addr); void eeh_slot_error_detail(struct eeh_pe *pe, int severity); int eeh_pci_enable(struct eeh_pe *pe, int function); -int eeh_reset_pe(struct eeh_pe *); +int eeh_pe_reset_full(struct eeh_pe *pe); void eeh_save_bars(struct eeh_dev *edev); int rtas_write_config(struct pci_dn *, int where, int size, u32 val); int rtas_read_config(struct pci_dn *, int where, int size, u32 *val); diff --git a/arch/powerpc/kernel/eeh.c b/arch/powerpc/kernel/eeh.c index 927d16269ad6..8180bfd7ab93 100644 --- a/arch/powerpc/kernel/eeh.c +++ b/arch/powerpc/kernel/eeh.c @@ -808,76 +808,67 @@ static void *eeh_set_dev_freset(void *data, void *flag) } /** - * eeh_reset_pe_once - Assert the pci #RST line for 1/4 second + * eeh_pe_reset_full - Complete a full reset process on the indicated PE * @pe: EEH PE * - * Assert the PCI #RST line for 1/4 second. + * This function executes a full reset procedure on a PE, including setting + * the appropriate flags, performing a fundamental or hot reset, and then + * deactivating the reset status. It is designed to be used within the EEH + * subsystem, as opposed to eeh_pe_reset which is exported to drivers and + * only performs a single operation at a time. + * + * This function will attempt to reset a PE three times before failing. */ -static void eeh_reset_pe_once(struct eeh_pe *pe) +int eeh_pe_reset_full(struct eeh_pe *pe) { + int active_flags = (EEH_STATE_MMIO_ACTIVE | EEH_STATE_DMA_ACTIVE); + int reset_state = (EEH_PE_RESET | EEH_PE_CFG_BLOCKED); + int type = EEH_RESET_HOT; unsigned int freset = 0; + int i, state, ret; - /* Determine type of EEH reset required for - * Partitionable Endpoint, a hot-reset (1) - * or a fundamental reset (3). - * A fundamental reset required by any device under - * Partitionable Endpoint trumps hot-reset. + /* + * Determine the type of reset to perform - hot or fundamental. + * Hot reset is the default operation, unless any device under the + * PE requires a fundamental reset. */ eeh_pe_dev_traverse(pe, eeh_set_dev_freset, &freset); if (freset) - eeh_ops->reset(pe, EEH_RESET_FUNDAMENTAL); - else - eeh_ops->reset(pe, EEH_RESET_HOT); - - eeh_ops->reset(pe, EEH_RESET_DEACTIVATE); -} - -/** - * eeh_reset_pe - Reset the indicated PE - * @pe: EEH PE - * - * This routine should be called to reset indicated device, including - * PE. A PE might include multiple PCI devices and sometimes PCI bridges - * might be involved as well. - */ -int eeh_reset_pe(struct eeh_pe *pe) -{ - int flags = (EEH_STATE_MMIO_ACTIVE | EEH_STATE_DMA_ACTIVE); - int i, state, ret; + type = EEH_RESET_FUNDAMENTAL; - /* Mark as reset and block config space */ - eeh_pe_state_mark(pe, EEH_PE_RESET | EEH_PE_CFG_BLOCKED); + /* Mark the PE as in reset state and block config space accesses */ + eeh_pe_state_mark(pe, reset_state); - /* Take three shots at resetting the bus */ + /* Make three attempts at resetting the bus */ for (i = 0; i < 3; i++) { - eeh_reset_pe_once(pe); + ret = eeh_pe_reset(pe, type); + if (ret) + break; - /* - * EEH_PE_ISOLATED is expected to be removed after - * BAR restore. - */ + ret = eeh_pe_reset(pe, EEH_RESET_DEACTIVATE); + if (ret) + break; + + /* Wait until the PE is in a functioning state */ state = eeh_ops->wait_state(pe, PCI_BUS_RESET_WAIT_MSEC); - if ((state & flags) == flags) { - ret = 0; - goto out; - } + if ((state & active_flags) == active_flags) + break; if (state < 0) { pr_warn("%s: Unrecoverable slot failure on PHB#%x-PE#%x", __func__, pe->phb->global_number, pe->addr); ret = -ENOTRECOVERABLE; - goto out; + break; } - /* We might run out of credits */ + /* Set error in case this is our last attempt */ ret = -EIO; pr_warn("%s: Failure %d resetting PHB#%x-PE#%x\n (%d)\n", __func__, state, pe->phb->global_number, pe->addr, (i + 1)); } -out: - eeh_pe_state_clear(pe, EEH_PE_RESET | EEH_PE_CFG_BLOCKED); + eeh_pe_state_clear(pe, reset_state); return ret; } @@ -1601,6 +1592,7 @@ static int eeh_pe_reenable_devices(struct eeh_pe *pe) return eeh_unfreeze_pe(pe, true); } + /** * eeh_pe_reset - Issue PE reset according to specified type * @pe: EEH PE diff --git a/arch/powerpc/kernel/eeh_driver.c b/arch/powerpc/kernel/eeh_driver.c index ac984d2038ab..555a47bd5d1a 100644 --- a/arch/powerpc/kernel/eeh_driver.c +++ b/arch/powerpc/kernel/eeh_driver.c @@ -588,7 +588,7 @@ int eeh_pe_reset_and_recover(struct eeh_pe *pe) eeh_pe_dev_traverse(pe, eeh_dev_save_state, NULL); /* Issue reset */ - ret = eeh_reset_pe(pe); + ret = eeh_pe_reset_full(pe); if (ret) { eeh_pe_state_clear(pe, EEH_PE_RECOVERING); return ret; @@ -659,7 +659,7 @@ static int eeh_reset_device(struct eeh_pe *pe, struct pci_bus *bus, * config accesses. So we prefer to block them. However, controlled * PCI config accesses initiated from EEH itself are allowed. */ - rc = eeh_reset_pe(pe); + rc = eeh_pe_reset_full(pe); if (rc) return rc; -- GitLab