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Commit 9a123f19 authored by Tomas Winkler's avatar Tomas Winkler Committed by Greg Kroah-Hartman
Browse files

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 07b509b7

drivers/misc/mei/main.c

+27 −0
Original line number Diff line number Diff line
@@ -905,6 +905,27 @@ 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

 *
@@ -920,6 +941,12 @@ 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;