PCI: Add support for non-BAR ROMs

Platforms may provide their own mechanisms for obtaining ROMs. Add support
for using data provided by the platform in that case.

Signed-off-by: Matthew Garrett <mjg@redhat.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Tested-by: Seth Forshee <seth.forshee@canonical.com>

2 files changed, 11 insertions, 2 deletions

diff --git a/drivers/pci/rom.c b/drivers/pci/rom.c
index 0b3037ab8b93..3a3828fbc879 100644
--- a/drivers/pci/rom.c
+++ b/drivers/pci/rom.c
@@ -118,11 +118,17 @@ void __iomem *pci_map_rom(struct pci_dev *pdev, size_t *size)
         void __iomem *rom;
 
         /*
+         * Some devices may provide ROMs via a source other than the BAR
+         */
+        if (pdev->rom && pdev->romlen) {
+                *size = pdev->romlen;
+                return phys_to_virt((phys_addr_t)pdev->rom);
+        /*
          * IORESOURCE_ROM_SHADOW set on x86, x86_64 and IA64 supports legacy
          * memory map if the VGA enable bit of the Bridge Control register is
          * set for embedded VGA.
          */
-        if (res->flags & IORESOURCE_ROM_SHADOW) {
+        } else if (res->flags & IORESOURCE_ROM_SHADOW) {
                 /* primary video rom always starts here */
                 start = (loff_t)0xC0000;
                 *size = 0x20000; /* cover C000:0 through E000:0 */
@@ -181,7 +187,8 @@ void pci_unmap_rom(struct pci_dev *pdev, void __iomem *rom)
         if (res->flags & (IORESOURCE_ROM_COPY | IORESOURCE_ROM_BIOS_COPY))
                 return;
 
-        iounmap(rom);
+        if (!pdev->rom || !pdev->romlen)
+                iounmap(rom);
 
         /* Disable again before continuing, leave enabled if pci=rom */
         if (!(res->flags & (IORESOURCE_ROM_ENABLE | IORESOURCE_ROM_SHADOW)))
diff --git a/include/linux/pci.h b/include/linux/pci.h
index 195c2593bd31..f116b2d859dc 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -333,6 +333,8 @@ struct pci_dev {
         };
         struct pci_ats  *ats;   /* Address Translation Service */
 #endif
+        void *rom; /* Physical pointer to ROM if it's not from the BAR */
+        size_t romlen; /* Length of ROM if it's not from the BAR */
 };
 
 static inline struct pci_dev *pci_physfn(struct pci_dev *dev)