132 lines
3.2 KiB
C
132 lines
3.2 KiB
C
/*
|
|
* 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 (!dev->is_pcie)
|
|
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 (!dev->is_pcie)
|
|
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;
|
|
}
|