PCI: Introduce named defines for PCI ROM

Convert the magic numbers associated with PCI ROM into named
definitions. Some of these definitions will be used in the second
fix patch.

Signed-off-by: Guixin Liu <kanie@linux.alibaba.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@intel.com>
Reviewed-by: Krzysztof Wilczyński <kwilczynski@kernel.org>
Link: https://patch.msgid.link/20260508082128.3344255-2-kanie@linux.alibaba.com

diff --git a/drivers/pci/rom.c b/drivers/pci/rom.c
index e18d3a4383ba6b0071fe946b798f013b9abbe638..d4a141bd148b4bbb97c94c0e25716ef57e610f50 100644 (file)
--- a/drivers/pci/rom.c
+++ b/drivers/pci/rom.c
@@ -5,13 +5,28 @@
  * (C) Copyright 2004 Jon Smirl <jonsmirl@yahoo.com>
  * (C) Copyright 2004 Silicon Graphics, Inc. Jesse Barnes <jbarnes@sgi.com>
  */
+
+#include <linux/bits.h>
 #include <linux/kernel.h>
 #include <linux/export.h>
 #include <linux/pci.h>
+#include <linux/sizes.h>
 #include <linux/slab.h>
 
 #include "pci.h"
 
+#define PCI_ROM_HEADER_SIZE                    0x1A
+#define PCI_ROM_POINTER_TO_DATA_STRUCT         0x18
+#define PCI_ROM_LAST_IMAGE_INDICATOR           0x15
+#define PCI_ROM_LAST_IMAGE_INDICATOR_BIT       BIT(7)
+#define PCI_ROM_IMAGE_LEN                      0x10
+#define PCI_ROM_IMAGE_SECTOR_SIZE              SZ_512
+#define PCI_ROM_IMAGE_SIGNATURE                        0xAA55
+
+/* Data structure signature is "PCIR" in ASCII representation */
+#define PCI_ROM_DATA_STRUCT_SIGNATURE          0x52494350
+#define PCI_ROM_DATA_STRUCT_LEN                        0x0A
+
 /**
  * pci_enable_rom - enable ROM decoding for a PCI device
  * @pdev: PCI device to enable
@@ -91,26 +106,27 @@ static size_t pci_get_rom_size(struct pci_dev *pdev, void __iomem *rom,
        do {
                void __iomem *pds;
                /* Standard PCI ROMs start out with these bytes 55 AA */
-               if (readw(image) != 0xAA55) {
-                       pci_info(pdev, "Invalid PCI ROM header signature: expecting 0xaa55, got %#06x\n",
-                                readw(image));
+               if (readw(image) != PCI_ROM_IMAGE_SIGNATURE) {
+                       pci_info(pdev, "Invalid PCI ROM header signature: expecting %#06x, got %#06x\n",
+                                PCI_ROM_IMAGE_SIGNATURE, readw(image));
                        break;
                }
-               /* get the PCI data structure and check its "PCIR" signature */
-               pds = image + readw(image + 24);
-               if (readl(pds) != 0x52494350) {
-                       pci_info(pdev, "Invalid PCI ROM data signature: expecting 0x52494350, got %#010x\n",
-                                readl(pds));
+               /* Get the PCI data structure and check its "PCIR" signature */
+               pds = image + readw(image + PCI_ROM_POINTER_TO_DATA_STRUCT);
+               if (readl(pds) != PCI_ROM_DATA_STRUCT_SIGNATURE) {
+                       pci_info(pdev, "Invalid PCI ROM data signature: expecting %#010x, got %#010x\n",
+                                PCI_ROM_DATA_STRUCT_SIGNATURE, readl(pds));
                        break;
                }
-               last_image = readb(pds + 21) & 0x80;
-               length = readw(pds + 16);
-               image += length * 512;
+               last_image = readb(pds + PCI_ROM_LAST_IMAGE_INDICATOR) &
+                                  PCI_ROM_LAST_IMAGE_INDICATOR_BIT;
+               length = readw(pds + PCI_ROM_IMAGE_LEN);
+               image += length * PCI_ROM_IMAGE_SECTOR_SIZE;
                /* Avoid iterating through memory outside the resource window */
                if (image >= rom + size)
                        break;
                if (!last_image) {
-                       if (readw(image) != 0xAA55) {
+                       if (readw(image) != PCI_ROM_IMAGE_SIGNATURE) {
                                pci_info(pdev, "No more image in the PCI ROM\n");
                                break;
                        }