radeon: Attempt to use platform-provided ROM image

Some platforms only provide their PCI ROM via a platform-specific interface.
Fall back to attempting that if all other sources fail.

Signed-off-by: Matthew Garrett <matthew.garrett@nebula.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

diff --git a/drivers/gpu/drm/radeon/radeon_bios.c b/drivers/gpu/drm/radeon/radeon_bios.c
index b8015913d3823547425b91b1a1c323db6cb3bfb2..fa3c56fba294fe1a433b2d7b6a3e1507e357d1ca 100644 (file)
--- a/drivers/gpu/drm/radeon/radeon_bios.c
+++ b/drivers/gpu/drm/radeon/radeon_bios.c
@@ -99,6 +99,29 @@ static bool radeon_read_bios(struct radeon_device *rdev)
        return true;
 }
 
+static bool radeon_read_platform_bios(struct radeon_device *rdev)
+{
+       uint8_t __iomem *bios;
+       size_t size;
+
+       rdev->bios = NULL;
+
+       bios = pci_platform_rom(rdev->pdev, &size);
+       if (!bios) {
+               return false;
+       }
+
+       if (size == 0 || bios[0] != 0x55 || bios[1] != 0xaa) {
+               return false;
+       }
+       rdev->bios = kmemdup(bios, size, GFP_KERNEL);
+       if (rdev->bios == NULL) {
+               return false;
+       }
+
+       return true;
+}
+
 #ifdef CONFIG_ACPI
 /* ATRM is used to get the BIOS on the discrete cards in
  * dual-gpu systems.
@@ -620,6 +643,9 @@ bool radeon_get_bios(struct radeon_device *rdev)
        if (r == false) {
                r = radeon_read_disabled_bios(rdev);
        }
+       if (r == false) {
+               r = radeon_read_platform_bios(rdev);
+       }
        if (r == false || rdev->bios == NULL) {
                DRM_ERROR("Unable to locate a BIOS ROM\n");
                rdev->bios = NULL;