diff options
Diffstat (limited to 'drivers/pci/pcie/aer/ecrc.c')
| -rw-r--r-- | drivers/pci/pcie/aer/ecrc.c | 131 |
1 files changed, 131 insertions, 0 deletions
diff --git a/drivers/pci/pcie/aer/ecrc.c b/drivers/pci/pcie/aer/ecrc.c new file mode 100644 index 000000000..a2747a663 --- /dev/null +++ b/drivers/pci/pcie/aer/ecrc.c @@ -0,0 +1,131 @@ +/* + * Enables/disables PCIe ECRC checking. + * + * (C) Copyright 2009 Hewlett-Packard Development Company, L.P. + * Andrew Patterson <andrew.patterson@hp.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. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA + * 02111-1307, USA. + * + */ + +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/moduleparam.h> +#include <linux/pci.h> +#include <linux/pci_regs.h> +#include <linux/errno.h> +#include "../../pci.h" + +#define ECRC_POLICY_DEFAULT 0 /* ECRC set by BIOS */ +#define ECRC_POLICY_OFF 1 /* ECRC off for performance */ +#define ECRC_POLICY_ON 2 /* ECRC on for data integrity */ + +static int ecrc_policy = ECRC_POLICY_DEFAULT; + +static const char *ecrc_policy_str[] = { + [ECRC_POLICY_DEFAULT] = "bios", + [ECRC_POLICY_OFF] = "off", + [ECRC_POLICY_ON] = "on" +}; + +/** + * enable_ercr_checking - enable PCIe ECRC checking for a device + * @dev: the PCI device + * + * Returns 0 on success, or negative on failure. + */ +static int enable_ecrc_checking(struct pci_dev *dev) +{ + int pos; + u32 reg32; + + if (!pci_is_pcie(dev)) + return -ENODEV; + + pos = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_ERR); + if (!pos) + return -ENODEV; + + pci_read_config_dword(dev, pos + PCI_ERR_CAP, ®32); + if (reg32 & PCI_ERR_CAP_ECRC_GENC) + reg32 |= PCI_ERR_CAP_ECRC_GENE; + if (reg32 & PCI_ERR_CAP_ECRC_CHKC) + reg32 |= PCI_ERR_CAP_ECRC_CHKE; + pci_write_config_dword(dev, pos + PCI_ERR_CAP, reg32); + + return 0; +} + +/** + * disable_ercr_checking - disables PCIe ECRC checking for a device + * @dev: the PCI device + * + * Returns 0 on success, or negative on failure. + */ +static int disable_ecrc_checking(struct pci_dev *dev) +{ + int pos; + u32 reg32; + + if (!pci_is_pcie(dev)) + return -ENODEV; + + pos = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_ERR); + if (!pos) + return -ENODEV; + + pci_read_config_dword(dev, pos + PCI_ERR_CAP, ®32); + reg32 &= ~(PCI_ERR_CAP_ECRC_GENE | PCI_ERR_CAP_ECRC_CHKE); + pci_write_config_dword(dev, pos + PCI_ERR_CAP, reg32); + + return 0; +} + +/** + * pcie_set_ecrc_checking - set/unset PCIe ECRC checking for a device based on global policy + * @dev: the PCI device + */ +void pcie_set_ecrc_checking(struct pci_dev *dev) +{ + switch (ecrc_policy) { + case ECRC_POLICY_DEFAULT: + return; + case ECRC_POLICY_OFF: + disable_ecrc_checking(dev); + break; + case ECRC_POLICY_ON: + enable_ecrc_checking(dev); + break; + default: + return; + } +} + +/** + * pcie_ecrc_get_policy - parse kernel command-line ecrc option + */ +void pcie_ecrc_get_policy(char *str) +{ + int i; + + for (i = 0; i < ARRAY_SIZE(ecrc_policy_str); i++) + if (!strncmp(str, ecrc_policy_str[i], + strlen(ecrc_policy_str[i]))) + break; + if (i >= ARRAY_SIZE(ecrc_policy_str)) + return; + + ecrc_policy = i; +} |