[PATCH 3/4] PCI: PCIE AER: PCIE AER software error injection

Huang Ying
2009-04-24T02:46:12Z

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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/kernel/people/yhuang/

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 <ying.huang@intel.com>

---
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 | 472 +++++++++++++++++++++++++++++++++++++
4 files changed, 493 insertions(+)

--- /dev/null
+++ b/drivers/pci/pcie/aer/aer_inject.c
@@ -0,0 +1,472 @@
+/*
+ * 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/utils/pcie/aer-inject
+ *
+ * Copyright 2009 Intel Corporation.
+ * Huang Ying <ying.huang@intel.com>
+ *
+ * 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 <linux/module.h>
+#include <linux/init.h>
+#include <linux/miscdevice.h>
+#include <linux/pci.h>
+#include <linux/fs.h>
+#include <asm/uaccess.h>
+#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;
+ else {
+ if (sever & einj->uncor_status)
+ rperr->root_status |= PCI_ERR_ROOT_FIRST_FATAL;
+ }
+ if (!(sever & einj->uncor_status))
+ 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
@@ -10,3 +10,5 @@ config PCIEAER
This enables PCI Express Root Port Advanced Error Reporting
(AER) driver support. Error reporting messages sent to Root
Port will be handled by PCI Express AER driver.
+
+source "drivers/pci/pcie/aer/Kconfig.debug"
--- a/drivers/pci/pcie/aer/Makefile
+++ b/drivers/pci/pcie/aer/Makefile
@@ -7,3 +7,4 @@ obj-$(CONFIG_PCIEAER) += aerdriver.o
aerdriver-objs := aerdrv_errprint.o aerdrv_core.o aerdrv.o
aerdriver-$(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/utils/pcie/aer-inject

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