PCI/MSI: Remove "pos" from the struct msi_desc msi_attrib

"msi_attrib.pos" is only used for MSI (not MSI-X), and we already cache the
MSI capability offset in "dev->msi_cap".

Remove "pos" from the struct msi_attrib and use "dev->msi_cap" directly.

[bhelgaas: changelog, fix whitespace]
Signed-off-by: Yijing Wang <wangyijing@huawei.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

arch/mips/pci/msi-octeon.c

@@ -73,8 +73,7 @@ int arch_setup_msi_irq(struct pci_dev *dev, struct msi_desc *desc)
 	 * wants.  Most devices only want 1, which will give
 	 * configured_private_bits and request_private_bits equal 0.
 	 */
-	pci_read_config_word(dev, desc->msi_attrib.pos + PCI_MSI_FLAGS,
-			     &control);
+	pci_read_config_word(dev, dev->msi_cap + PCI_MSI_FLAGS, &control);
 
 	/*
 	 * If the number of private bits has been configured then use
@@ -176,8 +175,7 @@ msi_irq_allocated:
 	/* Update the number of IRQs the device has available to it */
 	control &= ~PCI_MSI_FLAGS_QSIZE;
 	control |= request_private_bits << 4;
-	pci_write_config_word(dev, desc->msi_attrib.pos + PCI_MSI_FLAGS,
-			      control);
+	pci_write_config_word(dev, dev->msi_cap + PCI_MSI_FLAGS, control);
 
 	irq_set_msi_desc(irq, desc);
 	write_msi_msg(irq, &msg);

drivers/pci/host/pcie-designware.c

@@ -355,9 +355,8 @@ static int dw_msi_setup_irq(struct msi_chip *chip, struct pci_dev *pdev,
 		return -EINVAL;
 	}
 
-	pci_read_config_word(pdev, desc->msi_attrib.pos+PCI_MSI_FLAGS,
-				&msg_ctr);
-	msgvec = (msg_ctr&PCI_MSI_FLAGS_QSIZE) >> 4;
+	pci_read_config_word(pdev, pdev->msi_cap + PCI_MSI_FLAGS, &msg_ctr);
+	msgvec = (msg_ctr & PCI_MSI_FLAGS_QSIZE) >> 4;
 	if (msgvec == 0)
 		msgvec = (msg_ctr & PCI_MSI_FLAGS_QMASK) >> 1;
 	if (msgvec > 5)

drivers/pci/msi.c

@@ -574,7 +574,6 @@ static struct msi_desc *msi_setup_entry(struct pci_dev *dev)
 	entry->msi_attrib.entry_nr	= 0;
 	entry->msi_attrib.maskbit	= !!(control & PCI_MSI_FLAGS_MASKBIT);
 	entry->msi_attrib.default_irq	= dev->irq;	/* Save IOAPIC IRQ */
-	entry->msi_attrib.pos		= dev->msi_cap;
 	entry->msi_attrib.multi_cap	= (control & PCI_MSI_FLAGS_QMASK) >> 1;
 
 	if (control & PCI_MSI_FLAGS_64BIT)
@@ -678,7 +677,6 @@ static int msix_setup_entries(struct pci_dev *dev, void __iomem *base,
 		entry->msi_attrib.is_64		= 1;
 		entry->msi_attrib.entry_nr	= entries[i].entry;
 		entry->msi_attrib.default_irq	= dev->irq;
-		entry->msi_attrib.pos		= dev->msix_cap;
 		entry->mask_base		= base;
 
 		list_add_tail(&entry->list, &dev->msi_list);

include/linux/msi.h

@@ -29,7 +29,6 @@ struct msi_desc {
 		__u8	multi_cap : 3;	/* log2 num of messages supported */
 		__u8	maskbit	: 1;	/* mask-pending bit supported ? */
 		__u8	is_64	: 1;	/* Address size: 0=32bit 1=64bit */
-		__u8	pos;		/* Location of the msi capability */
 		__u16	entry_nr;	/* specific enabled entry */
 		unsigned default_irq;	/* default pre-assigned irq */
 	} msi_attrib;