Commit a2f69853 authored by Tomas Winkler's avatar Tomas Winkler Committed by Greg Kroah-Hartman

mei: add mei_quirk_probe function

The main purpose of this function is to exclude ME devices
without support for MEI/HECI interface from binding

Currently affected systems are C600/X79 based servers
that expose PCI device even though it doesn't supported ME Interface.
MEI driver accessing such nonfunctional device can corrupt
the system.
Signed-off-by: default avatarTomas Winkler <tomas.winkler@intel.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 3e830955
......@@ -924,6 +924,27 @@ static struct miscdevice mei_misc_device = {
.minor = MISC_DYNAMIC_MINOR,
};
/**
* mei_quirk_probe - probe for devices that doesn't valid ME interface
* @pdev: PCI device structure
* @ent: entry into pci_device_table
*
* returns true if ME Interface is valid, false otherwise
*/
static bool __devinit mei_quirk_probe(struct pci_dev *pdev,
const struct pci_device_id *ent)
{
u32 reg;
if (ent->device == MEI_DEV_ID_PBG_1) {
pci_read_config_dword(pdev, 0x48, &reg);
/* make sure that bit 9 is up and bit 10 is down */
if ((reg & 0x600) == 0x200) {
dev_info(&pdev->dev, "Device doesn't have valid ME Interface\n");
return false;
}
}
return true;
}
/**
* mei_probe - Device Initialization Routine
*
......@@ -939,6 +960,12 @@ static int __devinit mei_probe(struct pci_dev *pdev,
int err;
mutex_lock(&mei_mutex);
if (!mei_quirk_probe(pdev, ent)) {
err = -ENODEV;
goto end;
}
if (mei_device) {
err = -EEXIST;
goto end;
......
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