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Commit bffac3c5 authored by Matthew Wilcox's avatar Matthew Wilcox Committed by Jesse Barnes
Browse files

PCI MSI: Fix undefined shift by 32 



Add an msi_mask() function which returns the correct bitmask for the
number of MSI interrupts you have.  This fixes an undefined bug in
msi_capability_init().

Signed-off-by: default avatarMatthew Wilcox <willy@linux.intel.com>
Signed-off-by: default avatarJesse Barnes <jbarnes@virtuousgeek.org>
parent 476e7fae

drivers/pci/msi.c

+11 −2
Original line number Diff line number Diff line
@@ -103,6 +103,16 @@ static void msix_set_enable(struct pci_dev *dev, int enable) 
	}

}



/*

 * Essentially, this is ((1 << (1 << x)) - 1), but without the

 * undefinedness of a << 32.

 */

static inline __attribute_const__ u32 msi_mask(unsigned x)

{

	static const u32 mask[] = { 1, 2, 4, 0xf, 0xff, 0xffff, 0xffffffff };

	return mask[x];

}



static void msix_flush_writes(struct irq_desc *desc)

{

	struct msi_desc *entry;
@@ -407,8 +417,7 @@ static int msi_capability_init(struct pci_dev *dev) 


		/* All MSIs are unmasked by default, Mask them all */

		pci_read_config_dword(dev, base, &maskbits);

		temp = (1 << multi_msi_capable(control));

		temp = ((temp - 1) & ~temp);

		temp = msi_mask((control & PCI_MSI_FLAGS_QMASK) >> 1);

		maskbits |= temp;

		pci_write_config_dword(dev, base, maskbits);

		entry->msi_attrib.maskbits_mask = temp;