PCI MSI: Define PCI_MSI_MASK_32/64

Impact: cleanup, improve readability

Define PCI_MSI_MASK_32/64 for 32/64bit devices, instead of using
implicit offset (-4), "PCI_MSI_MASK_BIT - 4" and "PCI_MSI_MASK_BIT".
Signed-off-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com>
Reviewed-by: Matthew Wilcox <willy@linux.intel.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>

drivers/pci/msi.c

@@ -381,7 +381,7 @@ static int msi_capability_init(struct pci_dev *dev, int nvec)
 	entry->msi_attrib.default_irq = dev->irq;	/* Save IOAPIC IRQ */
 	entry->msi_attrib.pos = pos;
 
-	entry->mask_pos = msi_mask_bits_reg(pos, entry->msi_attrib.is_64);
+	entry->mask_pos = msi_mask_reg(pos, entry->msi_attrib.is_64);
 	/* All MSIs are unmasked by default, Mask them all */
 	if (entry->msi_attrib.maskbit)
 		pci_read_config_dword(dev, entry->mask_pos, &entry->masked);

drivers/pci/msi.h

@@ -16,9 +16,9 @@
 #define msi_lower_address_reg(base)	(base + PCI_MSI_ADDRESS_LO)
 #define msi_upper_address_reg(base)	(base + PCI_MSI_ADDRESS_HI)
 #define msi_data_reg(base, is64bit)	\
-	( (is64bit == 1) ? base+PCI_MSI_DATA_64 : base+PCI_MSI_DATA_32 )
-#define msi_mask_bits_reg(base, is64bit) \
-	( (is64bit == 1) ? base+PCI_MSI_MASK_BIT : base+PCI_MSI_MASK_BIT-4)
+	(base + ((is64bit == 1) ? PCI_MSI_DATA_64 : PCI_MSI_DATA_32))
+#define msi_mask_reg(base, is64bit)	\
+	(base + ((is64bit == 1) ? PCI_MSI_MASK_64 : PCI_MSI_MASK_32))
 #define is_64bit_address(control)	(!!(control & PCI_MSI_FLAGS_64BIT))
 #define is_mask_bit_support(control)	(!!(control & PCI_MSI_FLAGS_MASKBIT))
 

include/linux/pci_regs.h

@@ -295,8 +295,9 @@
 #define PCI_MSI_ADDRESS_LO	4	/* Lower 32 bits */
 #define PCI_MSI_ADDRESS_HI	8	/* Upper 32 bits (if PCI_MSI_FLAGS_64BIT set) */
 #define PCI_MSI_DATA_32		8	/* 16 bits of data for 32-bit devices */
+#define PCI_MSI_MASK_32		12	/* Mask bits register for 32-bit devices */
 #define PCI_MSI_DATA_64		12	/* 16 bits of data for 64-bit devices */
-#define PCI_MSI_MASK_BIT	16	/* Mask bits register */
+#define PCI_MSI_MASK_64		16	/* Mask bits register for 64-bit devices */
 
 /* MSI-X registers (these are at offset PCI_MSIX_FLAGS) */
 #define PCI_MSIX_FLAGS		2