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mei: add mei_quirk_probe function

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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: Tomas Winkler <tomas.winkler@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Tomas Winkler 2012-08-06 15:23:55 +03:00 committed by Greg Kroah-Hartman
parent 07b509b794
commit 9a123f1983
1 changed files with 27 additions and 0 deletions
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27
drivers/misc/mei/main.c
View file

@ -905,6 +905,27 @@ static struct miscdevice mei_misc_device = {
.minor = MISC_DYNAMIC_MINOR, .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 * mei_probe - Device Initialization Routine
* *
@ -920,6 +941,12 @@ static int __devinit mei_probe(struct pci_dev *pdev,
int err; int err;
mutex_lock(&mei_mutex); mutex_lock(&mei_mutex);
if (!mei_quirk_probe(pdev, ent)) {
err = -ENODEV;
goto end;
}
if (mei_device) { if (mei_device) {
err = -EEXIST; err = -EEXIST;
goto end; goto end;