x86: Use PCI setup data

EFI can provide PCI ROMs out of band via boot services, which may not be
available after boot. Add support for using the data handed off to us by
the boot stub or bootloader.

[bhelgaas: added Seth's boot_params section mismatch fix]
[bhelgaas: drop "boot_params.hdr.version < 0x0209" test]
Signed-off-by: Matthew Garrett <mjg@redhat.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Tested-by: Seth Forshee <seth.forshee@canonical.com>

arch/x86/kernel/setup.c

@@ -143,11 +143,7 @@ int default_check_phys_apicid_present(int phys_apicid)
 }
 #endif
 
-#ifndef CONFIG_DEBUG_BOOT_PARAMS
-struct boot_params __initdata boot_params;
-#else
 struct boot_params boot_params;
-#endif
 
 /*
  * Machine setup..

arch/x86/pci/common.c

@@ -17,6 +17,7 @@
 #include <asm/io.h>
 #include <asm/smp.h>
 #include <asm/pci_x86.h>
+#include <asm/setup.h>
 
 unsigned int pci_probe = PCI_PROBE_BIOS | PCI_PROBE_CONF1 | PCI_PROBE_CONF2 |
 				PCI_PROBE_MMCONF;
@@ -608,6 +609,35 @@ unsigned int pcibios_assign_all_busses(void)
 	return (pci_probe & PCI_ASSIGN_ALL_BUSSES) ? 1 : 0;
 }
 
+int pcibios_add_device(struct pci_dev *dev)
+{
+	struct setup_data *data;
+	struct pci_setup_rom *rom;
+	u64 pa_data;
+
+	pa_data = boot_params.hdr.setup_data;
+	while (pa_data) {
+		data = phys_to_virt(pa_data);
+
+		if (data->type == SETUP_PCI) {
+			rom = (struct pci_setup_rom *)data;
+
+			if ((pci_domain_nr(dev->bus) == rom->segment) &&
+			    (dev->bus->number == rom->bus) &&
+			    (PCI_SLOT(dev->devfn) == rom->device) &&
+			    (PCI_FUNC(dev->devfn) == rom->function) &&
+			    (dev->vendor == rom->vendor) &&
+			    (dev->device == rom->devid)) {
+				dev->rom = (void *)(unsigned long)(pa_data +
+				      offsetof(struct pci_setup_rom, romdata));
+				dev->romlen = rom->pcilen;
+			}
+		}
+		pa_data = data->next;
+	}
+	return 0;
+}
+
 int pcibios_enable_device(struct pci_dev *dev, int mask)
 {
 	int err;