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 000000000000..ece97df4df6d
--- /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 (!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, &reg32);
+        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, &reg32);
+        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;
+}