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Commit 314e77b3 authored by Michael Ellerman's avatar Michael Ellerman Committed by Greg Kroah-Hartman
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MSI: Remove dev->first_msi_irq 



Now that we keep a list of msi descriptors, we don't need first_msi_irq
in the pci dev.

If we somehow have zero MSIs configured list_entry() will give us weird
oopes or nice memory corruption bugs. So be paranoid. Add BUG_ONs and also
a check in pci_msi_check_device() to make sure nvec > 0.

Signed-off-by: default avatarMichael Ellerman <michael@ellerman.id.au>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@suse.de>
parent 4aa9bc95

drivers/pci/msi.c

+20 −11
Original line number Diff line number Diff line
@@ -269,7 +269,8 @@ static void __pci_restore_msix_state(struct pci_dev *dev) 
		msi_set_mask_bit(entry->irq, entry->msi_attrib.masked);

	}



	entry = get_irq_msi(dev->first_msi_irq);

	BUG_ON(list_empty(&dev->msi_list));

	entry = list_entry(dev->msi_list.next, struct msi_desc, list);

	pos = entry->msi_attrib.pos;

	pci_read_config_word(dev, pos + PCI_MSIX_FLAGS, &control);

	control &= ~PCI_MSIX_FLAGS_MASKALL;
@@ -341,7 +342,6 @@ static int msi_capability_init(struct pci_dev *dev) 
	}

	entry->irq = irq;

	list_add(&entry->list, &dev->msi_list);

	dev->first_msi_irq = irq;

	set_irq_msi(irq, entry);



	/* Set MSI enabled bits	 */
@@ -433,7 +433,6 @@ static int msix_capability_init(struct pci_dev *dev, 
			avail = -EBUSY;

		return avail;

	}

	dev->first_msi_irq = entries[0].vector;

	/* Set MSI-X enabled bits */

	pci_intx(dev, 0);		/* disable intx */

	msix_set_enable(dev, 1);
@@ -461,6 +460,14 @@ static int pci_msi_check_device(struct pci_dev* dev, int nvec, int type) 
	if (!pci_msi_enable || !dev || dev->no_msi)

		return -EINVAL;



	/*

	 * You can't ask to have 0 or less MSIs configured.

	 *  a) it's stupid ..

	 *  b) the list manipulation code assumes nvec >= 1.

	 */

	if (nvec < 1)

		return -ERANGE;



	/* Any bridge which does NOT route MSI transactions from it's

	 * secondary bus to it's primary bus must set NO_MSI flag on

	 * the secondary pci_bus.
@@ -525,18 +532,17 @@ void pci_disable_msi(struct pci_dev* dev) 
	pci_intx(dev, 1);		/* enable intx */

	dev->msi_enabled = 0;



	entry = get_irq_msi(dev->first_msi_irq);

	if (!entry || !entry->dev || entry->msi_attrib.type != PCI_CAP_ID_MSI) {

	BUG_ON(list_empty(&dev->msi_list));

	entry = list_entry(dev->msi_list.next, struct msi_desc, list);

	if (!entry->dev || entry->msi_attrib.type != PCI_CAP_ID_MSI) {

		return;

	}



	default_irq = entry->msi_attrib.default_irq;

	msi_free_irq(dev, dev->first_msi_irq);

	msi_free_irq(dev, entry->irq);



	/* Restore dev->irq to its default pin-assertion irq */

	dev->irq = default_irq;



	dev->first_msi_irq = 0;

}

EXPORT_SYMBOL(pci_disable_msi);
@@ -634,7 +640,6 @@ static void msix_free_all_irqs(struct pci_dev *dev) 


	list_for_each_entry(entry, &dev->msi_list, list)

		msi_free_irq(dev, entry->irq);

	dev->first_msi_irq = 0;

}



void pci_disable_msix(struct pci_dev* dev)
@@ -664,8 +669,12 @@ void msi_remove_pci_irq_vectors(struct pci_dev* dev) 
	if (!pci_msi_enable || !dev)

 		return;



	if (dev->msi_enabled)

		msi_free_irq(dev, dev->first_msi_irq);

	if (dev->msi_enabled) {

		struct msi_desc *entry;

		BUG_ON(list_empty(&dev->msi_list));

		entry = list_entry(dev->msi_list.next, struct msi_desc, list);

		msi_free_irq(dev, entry->irq);

	}



	if (dev->msix_enabled)

		msix_free_all_irqs(dev);

include/linux/pci.h

+0 −1
Original line number Diff line number Diff line
@@ -189,7 +189,6 @@ struct pci_dev { 
	int rom_attr_enabled;		/* has display of the rom attribute been enabled? */

	struct bin_attribute *res_attr[DEVICE_COUNT_RESOURCE]; /* sysfs file for resources */

#ifdef CONFIG_PCI_MSI

	unsigned int first_msi_irq;

	struct list_head msi_list;

#endif

};