diff options
Diffstat (limited to 'arch/powerpc/kernel/eeh.c')
| -rw-r--r-- | arch/powerpc/kernel/eeh.c | 268 |
1 files changed, 268 insertions, 0 deletions
diff --git a/arch/powerpc/kernel/eeh.c b/arch/powerpc/kernel/eeh.c index c8f1a9d2a67b..18c40fd1e62a 100644 --- a/arch/powerpc/kernel/eeh.c +++ b/arch/powerpc/kernel/eeh.c @@ -40,6 +40,7 @@ #include <asm/eeh.h> #include <asm/eeh_event.h> #include <asm/io.h> +#include <asm/iommu.h> #include <asm/machdep.h> #include <asm/ppc-pci.h> #include <asm/rtas.h> @@ -108,6 +109,9 @@ struct eeh_ops *eeh_ops = NULL; /* Lock to avoid races due to multiple reports of an error */ DEFINE_RAW_SPINLOCK(confirm_error_lock); +/* Lock to protect passed flags */ +static DEFINE_MUTEX(eeh_dev_mutex); + /* Buffer for reporting pci register dumps. Its here in BSS, and * not dynamically alloced, so that it ends up in RMO where RTAS * can access it. @@ -1108,6 +1112,270 @@ void eeh_remove_device(struct pci_dev *dev) edev->mode &= ~EEH_DEV_SYSFS; } +/** + * eeh_dev_open - Increase count of pass through devices for PE + * @pdev: PCI device + * + * Increase count of passed through devices for the indicated + * PE. In the result, the EEH errors detected on the PE won't be + * reported. The PE owner will be responsible for detection + * and recovery. + */ +int eeh_dev_open(struct pci_dev *pdev) +{ + struct eeh_dev *edev; + + mutex_lock(&eeh_dev_mutex); + + /* No PCI device ? */ + if (!pdev) + goto out; + + /* No EEH device or PE ? */ + edev = pci_dev_to_eeh_dev(pdev); + if (!edev || !edev->pe) + goto out; + + /* Increase PE's pass through count */ + atomic_inc(&edev->pe->pass_dev_cnt); + mutex_unlock(&eeh_dev_mutex); + + return 0; +out: + mutex_unlock(&eeh_dev_mutex); + return -ENODEV; +} +EXPORT_SYMBOL_GPL(eeh_dev_open); + +/** + * eeh_dev_release - Decrease count of pass through devices for PE + * @pdev: PCI device + * + * Decrease count of pass through devices for the indicated PE. If + * there is no passed through device in PE, the EEH errors detected + * on the PE will be reported and handled as usual. + */ +void eeh_dev_release(struct pci_dev *pdev) +{ + struct eeh_dev *edev; + + mutex_lock(&eeh_dev_mutex); + + /* No PCI device ? */ + if (!pdev) + goto out; + + /* No EEH device ? */ + edev = pci_dev_to_eeh_dev(pdev); + if (!edev || !edev->pe || !eeh_pe_passed(edev->pe)) + goto out; + + /* Decrease PE's pass through count */ + atomic_dec(&edev->pe->pass_dev_cnt); + WARN_ON(atomic_read(&edev->pe->pass_dev_cnt) < 0); +out: + mutex_unlock(&eeh_dev_mutex); +} +EXPORT_SYMBOL(eeh_dev_release); + +/** + * eeh_iommu_group_to_pe - Convert IOMMU group to EEH PE + * @group: IOMMU group + * + * The routine is called to convert IOMMU group to EEH PE. + */ +struct eeh_pe *eeh_iommu_group_to_pe(struct iommu_group *group) +{ + struct iommu_table *tbl; + struct pci_dev *pdev = NULL; + struct eeh_dev *edev; + bool found = false; + + /* No IOMMU group ? */ + if (!group) + return NULL; + + /* No PCI device ? */ + for_each_pci_dev(pdev) { + tbl = get_iommu_table_base(&pdev->dev); + if (tbl && tbl->it_group == group) { + found = true; + break; + } + } + if (!found) + return NULL; + + /* No EEH device or PE ? */ + edev = pci_dev_to_eeh_dev(pdev); + if (!edev || !edev->pe) + return NULL; + + return edev->pe; +} + +/** + * eeh_pe_set_option - Set options for the indicated PE + * @pe: EEH PE + * @option: requested option + * + * The routine is called to enable or disable EEH functionality + * on the indicated PE, to enable IO or DMA for the frozen PE. + */ +int eeh_pe_set_option(struct eeh_pe *pe, int option) +{ + int ret = 0; + + /* Invalid PE ? */ + if (!pe) + return -ENODEV; + + /* + * EEH functionality could possibly be disabled, just + * return error for the case. And the EEH functinality + * isn't expected to be disabled on one specific PE. + */ + switch (option) { + case EEH_OPT_ENABLE: + if (eeh_enabled()) + break; + ret = -EIO; + break; + case EEH_OPT_DISABLE: + break; + case EEH_OPT_THAW_MMIO: + case EEH_OPT_THAW_DMA: + if (!eeh_ops || !eeh_ops->set_option) { + ret = -ENOENT; + break; + } + + ret = eeh_ops->set_option(pe, option); + break; + default: + pr_debug("%s: Option %d out of range (%d, %d)\n", + __func__, option, EEH_OPT_DISABLE, EEH_OPT_THAW_DMA); + ret = -EINVAL; + } + + return ret; +} +EXPORT_SYMBOL_GPL(eeh_pe_set_option); + +/** + * eeh_pe_get_state - Retrieve PE's state + * @pe: EEH PE + * + * Retrieve the PE's state, which includes 3 aspects: enabled + * DMA, enabled IO and asserted reset. + */ +int eeh_pe_get_state(struct eeh_pe *pe) +{ + int result, ret = 0; + bool rst_active, dma_en, mmio_en; + + /* Existing PE ? */ + if (!pe) + return -ENODEV; + + if (!eeh_ops || !eeh_ops->get_state) + return -ENOENT; + + result = eeh_ops->get_state(pe, NULL); + rst_active = !!(result & EEH_STATE_RESET_ACTIVE); + dma_en = !!(result & EEH_STATE_DMA_ENABLED); + mmio_en = !!(result & EEH_STATE_MMIO_ENABLED); + + if (rst_active) + ret = EEH_PE_STATE_RESET; + else if (dma_en && mmio_en) + ret = EEH_PE_STATE_NORMAL; + else if (!dma_en && !mmio_en) + ret = EEH_PE_STATE_STOPPED_IO_DMA; + else if (!dma_en && mmio_en) + ret = EEH_PE_STATE_STOPPED_DMA; + else + ret = EEH_PE_STATE_UNAVAIL; + + return ret; +} +EXPORT_SYMBOL_GPL(eeh_pe_get_state); + +/** + * eeh_pe_reset - Issue PE reset according to specified type + * @pe: EEH PE + * @option: reset type + * + * The routine is called to reset the specified PE with the + * indicated type, either fundamental reset or hot reset. + * PE reset is the most important part for error recovery. + */ +int eeh_pe_reset(struct eeh_pe *pe, int option) +{ + int ret = 0; + + /* Invalid PE ? */ + if (!pe) + return -ENODEV; + + if (!eeh_ops || !eeh_ops->set_option || !eeh_ops->reset) + return -ENOENT; + + switch (option) { + case EEH_RESET_DEACTIVATE: + ret = eeh_ops->reset(pe, option); + if (ret) + break; + + /* + * The PE is still in frozen state and we need to clear + * that. It's good to clear frozen state after deassert + * to avoid messy IO access during reset, which might + * cause recursive frozen PE. + */ + ret = eeh_ops->set_option(pe, EEH_OPT_THAW_MMIO); + if (!ret) + ret = eeh_ops->set_option(pe, EEH_OPT_THAW_DMA); + if (!ret) + eeh_pe_state_clear(pe, EEH_PE_ISOLATED); + break; + case EEH_RESET_HOT: + case EEH_RESET_FUNDAMENTAL: + ret = eeh_ops->reset(pe, option); + break; + default: + pr_debug("%s: Unsupported option %d\n", + __func__, option); + ret = -EINVAL; + } + + return ret; +} +EXPORT_SYMBOL_GPL(eeh_pe_reset); + +/** + * eeh_pe_configure - Configure PCI bridges after PE reset + * @pe: EEH PE + * + * The routine is called to restore the PCI config space for + * those PCI devices, especially PCI bridges affected by PE + * reset issued previously. + */ +int eeh_pe_configure(struct eeh_pe *pe) +{ + int ret = 0; + + /* Invalid PE ? */ + if (!pe) + return -ENODEV; + + /* Restore config space for the affected devices */ + eeh_pe_restore_bars(pe); + + return ret; +} +EXPORT_SYMBOL_GPL(eeh_pe_configure); + static int proc_eeh_show(struct seq_file *m, void *v) { if (!eeh_enabled()) { |