From: Huang Ying Subject: pci: PCIE AER software error injection Debugging PCIE AER code can be very difficult because it is hard to trigger various real hardware errors. This patch provide a software based error injection tool, which can fake various PCIE errors with a user space helper tool named "aer-inject". Which can be gotten from: http://www.kernel.org/pub/linux/utils/pci/aer-inject/ The patch fakes AER error by faking some PCIE AER related registers and an AER interrupt for specified the PCIE device. Signed-off-by: Huang Ying --- drivers/pci/pcie/aer/Kconfig | 2 drivers/pci/pcie/aer/Kconfig.debug | 18 + drivers/pci/pcie/aer/Makefile | 1 drivers/pci/pcie/aer/aer_inject.c | 473 +++++++++++++++++++++++++++++++++++++ 4 files changed, 494 insertions(+) --- /dev/null +++ b/drivers/pci/pcie/aer/aer_inject.c @@ -0,0 +1,473 @@ +/* + * PCIE AER software error injection support. + * + * Debuging PCIE AER code is quite difficult because it is hard to + * trigger various real hardware errors. Software based error + * injection can fake almost all kinds of errors with the help of a + * user space helper tool aer-inject, which can be gotten from: + * http://www.kernel.org/pub/linux/utils/pci/aer-inject/ + * + * Copyright 2009 Intel Corporation. + * Huang Ying + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation; version 2 + * of the License. + * + */ + +#include +#include +#include +#include +#include +#include +#include "aerdrv.h" + +struct aer_error_inj +{ + u8 bus; + u8 dev; + u8 fn; + u32 uncor_status; + u32 cor_status; + u32 header_log0; + u32 header_log1; + u32 header_log2; + u32 header_log3; +}; + +struct aer_error +{ + struct list_head list; + unsigned int bus; + unsigned int devfn; + int pos_cap_err; + + u32 uncor_status; + u32 cor_status; + u32 header_log0; + u32 header_log1; + u32 header_log2; + u32 header_log3; + u32 root_status; + u32 source_id; +}; + +struct pci_bus_ops +{ + struct list_head list; + struct pci_bus *bus; + struct pci_ops *ops; +}; + +static LIST_HEAD(einjected); + +static LIST_HEAD(pci_bus_ops_list); + +/* Protect einjected and pci_bus_ops_list */ +static DEFINE_SPINLOCK(inject_lock); + +static void aer_error_init(struct aer_error *err, unsigned int bus, + unsigned int devfn, int pos_cap_err) +{ + INIT_LIST_HEAD(&err->list); + err->bus = bus; + err->devfn = devfn; + err->pos_cap_err = pos_cap_err; +} + +/* inject_lock must be held before calling */ +static struct aer_error *__find_aer_error(unsigned int bus, unsigned int devfn) +{ + struct aer_error *err; + + list_for_each_entry(err, &einjected, list) { + if (bus == err->bus && devfn == err->devfn) + return err; + } + return NULL; +} + +/* inject_lock must be held before calling */ +static struct aer_error *__find_aer_error_by_dev(struct pci_dev *dev) +{ + return __find_aer_error(dev->bus->number, dev->devfn); +} + +/* inject_lock must be held before calling */ +static struct pci_ops *__find_pci_bus_ops(struct pci_bus *bus) +{ + struct pci_bus_ops *bus_ops; + + list_for_each_entry(bus_ops, &pci_bus_ops_list, list) { + if (bus_ops->bus == bus) + return bus_ops->ops; + } + return NULL; +} + +static struct pci_bus_ops *pci_bus_ops_pop(void) +{ + unsigned long flags; + struct pci_bus_ops *bus_ops = NULL; + + spin_lock_irqsave(&inject_lock, flags); + if (list_empty(&pci_bus_ops_list)) + bus_ops = NULL; + else { + struct list_head *lh = pci_bus_ops_list.next; + list_del(lh); + bus_ops = list_entry(lh, struct pci_bus_ops, list); + } + spin_unlock_irqrestore(&inject_lock, flags); + return bus_ops; +} + +static u32 *find_pci_config_dword(struct aer_error *err, int where, + int *prw1cs) +{ + int rw1cs = 0; + u32 *target = NULL; + + if (err->pos_cap_err == -1) + return NULL; + + switch (where - err->pos_cap_err) { + case PCI_ERR_UNCOR_STATUS: + target = &err->uncor_status; + rw1cs = 1; + break; + case PCI_ERR_COR_STATUS: + target = &err->cor_status; + rw1cs = 1; + break; + case PCI_ERR_HEADER_LOG: + target = &err->header_log0; + break; + case PCI_ERR_HEADER_LOG+4: + target = &err->header_log1; + break; + case PCI_ERR_HEADER_LOG+8: + target = &err->header_log2; + break; + case PCI_ERR_HEADER_LOG+12: + target = &err->header_log3; + break; + case PCI_ERR_ROOT_STATUS: + target = &err->root_status; + rw1cs = 1; + break; + case PCI_ERR_ROOT_COR_SRC: + target = &err->source_id; + break; + } + if (prw1cs) + *prw1cs = rw1cs; + return target; +} + +static int pci_read_aer(struct pci_bus *bus, unsigned int devfn, int where, + int size, u32 *val) +{ + u32 *sim; + struct aer_error *err; + unsigned long flags; + struct pci_ops *ops; + + spin_lock_irqsave(&inject_lock, flags); + if (size != sizeof(u32)) + goto out; + err = __find_aer_error(bus->number, devfn); + if (!err) + goto out; + + sim = find_pci_config_dword(err, where, NULL); + if (sim) { + *val = *sim; + spin_unlock_irqrestore(&inject_lock, flags); + return 0; + } +out: + ops = __find_pci_bus_ops(bus); + spin_unlock_irqrestore(&inject_lock, flags); + return ops->read(bus, devfn, where, size, val); +} + +int pci_write_aer(struct pci_bus *bus, unsigned int devfn, int where, int size, + u32 val) +{ + u32 *sim; + struct aer_error *err; + unsigned long flags; + int rw1cs; + struct pci_ops *ops; + + spin_lock_irqsave(&inject_lock, flags); + if (size != sizeof(u32)) + goto out; + err = __find_aer_error(bus->number, devfn); + if (!err) + goto out; + + sim = find_pci_config_dword(err, where, &rw1cs); + if (sim) { + if (rw1cs) + *sim ^= val; + else + *sim = val; + spin_unlock_irqrestore(&inject_lock, flags); + return 0; + } +out: + ops = __find_pci_bus_ops(bus); + spin_unlock_irqrestore(&inject_lock, flags); + return ops->write(bus, devfn, where, size, val); +} + +static struct pci_ops pci_ops_aer = { + .read = pci_read_aer, + .write = pci_write_aer, +}; + +static void pci_bus_ops_init(struct pci_bus_ops *bus_ops, + struct pci_bus *bus, + struct pci_ops *ops) +{ + INIT_LIST_HEAD(&bus_ops->list); + bus_ops->bus = bus; + bus_ops->ops = ops; +} + +static int pci_bus_set_aer_ops(struct pci_bus *bus) +{ + struct pci_ops *ops; + struct pci_bus_ops *bus_ops; + unsigned long flags; + + bus_ops = kmalloc(sizeof(*bus_ops), GFP_KERNEL); + if (!bus_ops) + return -ENOMEM; + ops = pci_bus_set_ops(bus, &pci_ops_aer); + spin_lock_irqsave(&inject_lock, flags); + if (ops == &pci_ops_aer) + goto out; + pci_bus_ops_init(bus_ops, bus, ops); + list_add(&bus_ops->list, &pci_bus_ops_list); + bus_ops = NULL; +out: + spin_unlock_irqrestore(&inject_lock, flags); + if (bus_ops) + kfree(bus_ops); + return 0; +} + +static struct pci_dev *pcie_find_root_port(struct pci_dev *dev) +{ + while (1) { + if (!dev->is_pcie) + break; + if (dev->pcie_type == PCI_EXP_TYPE_ROOT_PORT) + return dev; + if (!dev->bus->self) + break; + dev = dev->bus->self; + } + return NULL; +} + +static int find_aer_device_iter(struct device *device, void *data) +{ + struct pcie_device **result = data; + struct pcie_device *pcie_dev; + + if (device->bus == &pcie_port_bus_type) { + pcie_dev = to_pcie_device(device); + if (pcie_dev->service & PCIE_PORT_SERVICE_AER) { + *result = pcie_dev; + return 1; + } + } + return 0; +} + +static int find_aer_device(struct pci_dev *dev, struct pcie_device **result) +{ + return device_for_each_child(&dev->dev, result, find_aer_device_iter); +} + +static int aer_inject(struct aer_error_inj *einj) +{ + struct aer_error *err, *rperr; + struct aer_error *err_alloc = NULL, *rperr_alloc = NULL; + struct pci_dev *dev, *rpdev; + struct pcie_device *edev; + unsigned long flags; + unsigned int devfn = PCI_DEVFN(einj->dev, einj->fn); + int pos_cap_err, rp_pos_cap_err; + u32 sever; + int ret = 0; + + dev = pci_get_bus_and_slot(einj->bus, devfn); + if (!dev) + return -EINVAL; + rpdev = pcie_find_root_port(dev); + if (!rpdev) { + ret = -EINVAL; + goto out_put; + } + + pos_cap_err = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_ERR); + if (!pos_cap_err) { + ret = -EIO; + goto out_put; + } + pci_read_config_dword(dev, pos_cap_err + PCI_ERR_UNCOR_SEVER, &sever); + + rp_pos_cap_err = pci_find_ext_capability(rpdev, PCI_EXT_CAP_ID_ERR); + if (!rp_pos_cap_err) { + ret = -EIO; + goto out_put; + } + + err_alloc = kzalloc(sizeof(struct aer_error), GFP_KERNEL); + if (!err_alloc) { + ret = -ENOMEM; + goto out_put; + } + rperr_alloc = kzalloc(sizeof(struct aer_error), GFP_KERNEL); + if (!rperr_alloc) { + ret = -ENOMEM; + goto out_put; + } + + spin_lock_irqsave(&inject_lock, flags); + + err = __find_aer_error_by_dev(dev); + if (!err) { + err = err_alloc; + err_alloc = NULL; + aer_error_init(err, einj->bus, devfn, pos_cap_err); + list_add(&err->list, &einjected); + } + err->uncor_status |= einj->uncor_status; + err->cor_status |= einj->cor_status; + err->header_log0 = einj->header_log0; + err->header_log1 = einj->header_log1; + err->header_log2 = einj->header_log2; + err->header_log3 = einj->header_log3; + + rperr = __find_aer_error_by_dev(rpdev); + if (!rperr) { + rperr = rperr_alloc; + rperr_alloc = NULL; + aer_error_init(rperr, rpdev->bus->number, rpdev->devfn, + rp_pos_cap_err); + list_add(&rperr->list, &einjected); + } + if (einj->cor_status) { + if (rperr->root_status & PCI_ERR_ROOT_COR_RCV) + rperr->root_status |= PCI_ERR_ROOT_MULTI_COR_RCV; + else + rperr->root_status |= PCI_ERR_ROOT_COR_RCV; + rperr->source_id &= 0xffff0000; + rperr->source_id |= (einj->bus << 8) | devfn; + } + if (einj->uncor_status) { + if (rperr->root_status & PCI_ERR_ROOT_UNCOR_RCV) + rperr->root_status |= PCI_ERR_ROOT_MULTI_UNCOR_RCV; + if (sever & einj->uncor_status) { + rperr->root_status |= PCI_ERR_ROOT_FATAL_RCV; + if (!(rperr->root_status & PCI_ERR_ROOT_UNCOR_RCV)) + rperr->root_status |= PCI_ERR_ROOT_FIRST_FATAL; + } else + rperr->root_status |= PCI_ERR_ROOT_NONFATAL_RCV; + rperr->root_status |= PCI_ERR_ROOT_UNCOR_RCV; + rperr->source_id &= 0x0000ffff; + rperr->source_id |= ((einj->bus << 8) | devfn) << 16; + } + spin_unlock_irqrestore(&inject_lock, flags); + + ret = pci_bus_set_aer_ops(dev->bus); + if (ret) + goto out_put; + ret = pci_bus_set_aer_ops(rpdev->bus); + if (ret) + goto out_put; + + if (find_aer_device(rpdev, &edev)) + aer_irq(-1, edev); + else + ret = -EINVAL; +out_put: + if (err_alloc) + kfree(err_alloc); + if (rperr_alloc) + kfree(rperr_alloc); + pci_dev_put(dev); + return ret; +} + +static ssize_t aer_inject_write(struct file *filp, const char __user *ubuf, + size_t usize, loff_t *off) +{ + struct aer_error_inj einj; + int ret; + + if (!capable(CAP_SYS_ADMIN)) + return -EPERM; + + if (usize != sizeof(struct aer_error_inj)) + return -EINVAL; + + if (copy_from_user(&einj, ubuf, usize)) + return -EFAULT; + + ret = aer_inject(&einj); + return ret ? ret : usize; +} + +static const struct file_operations aer_inject_fops = { + .write = aer_inject_write, + .owner = THIS_MODULE, +}; + +static struct miscdevice aer_inject_device = { + .minor = MISC_DYNAMIC_MINOR, + .name = "aer_inject", + .fops = &aer_inject_fops, +}; + +static int __init aer_inject_init(void) +{ + return misc_register(&aer_inject_device); +} + +static void __exit aer_inject_exit(void) +{ + struct aer_error *err, *err_next; + unsigned long flags; + struct pci_bus_ops *bus_ops; + + misc_deregister(&aer_inject_device); + + while ((bus_ops = pci_bus_ops_pop())) { + pci_bus_set_ops(bus_ops->bus, bus_ops->ops); + kfree(bus_ops); + } + + spin_lock_irqsave(&inject_lock, flags); + list_for_each_entry_safe(err, err_next, + &pci_bus_ops_list, list) { + list_del(&err->list); + kfree(err); + } + spin_unlock_irqrestore(&inject_lock, flags); +} + +module_init(aer_inject_init); +module_exit(aer_inject_exit); + +MODULE_DESCRIPTION("PCIE AER software error injector"); +MODULE_LICENSE("GPL"); --- a/drivers/pci/pcie/aer/Kconfig +++ b/drivers/pci/pcie/aer/Kconfig @@ -23,3 +23,5 @@ config PCIE_ECRC (transaction layer end-to-end CRC checking). When in doubt, say N. + +source "drivers/pci/pcie/aer/Kconfig.debug" --- a/drivers/pci/pcie/aer/Makefile +++ b/drivers/pci/pcie/aer/Makefile @@ -9,3 +9,4 @@ obj-$(CONFIG_PCIE_ECRC) += ecrc.o aerdriver-objs := aerdrv_errprint.o aerdrv_core.o aerdrv.o aerdriver-$(CONFIG_ACPI) += aerdrv_acpi.o +obj-$(CONFIG_PCIEAER_INJECT) += aer_inject.o --- /dev/null +++ b/drivers/pci/pcie/aer/Kconfig.debug @@ -0,0 +1,18 @@ +# +# PCI Express Root Port Device AER Debug Configuration +# + +config PCIEAER_INJECT + tristate "PCIE AER error injector support" + depends on PCIEAER + default n + help + This enables PCI Express Root Port Advanced Error Reporting + (AER) software error injector. + + Debuging PCIE AER code is quite difficult because it is hard + to trigger various real hardware errors. Software based + error injection can fake almost all kinds of errors with the + help of a user space helper tool aer-inject, which can be + gotten from: + http://www.kernel.org/pub/linux/utils/pci/aer-inject/