x86, EFI: Calculate the EFI framebuffer size instead of trusting the firmware

Seth Forshee reported that his system was reporting that the EFI framebuffer
stretched from 0x90010000-0xb0010000 despite the GPU's BAR only covering
0x90000000-0x9ffffff. It's safer to calculate this value from the pixel
stride and screen height (values we already depend on) rather than face
potential problems with resource allocation later on.

Signed-off-by: Matthew Garrett <mjg@redhat.com>
Tested-by: Seth Forshee <seth.forshee@canonical.com>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>

diff --git a/arch/x86/boot/compressed/eboot.c b/arch/x86/boot/compressed/eboot.c
index bbd83b9cb4dad29e36632dd7395f4992be4dea74..c760e073963ed59004f66ed65aade6355c852da9 100644 (file)
--- a/arch/x86/boot/compressed/eboot.c
+++ b/arch/x86/boot/compressed/eboot.c
@@ -331,7 +331,6 @@ static efi_status_t setup_gop(struct screen_info *si, efi_guid_t *proto,
        si->lfb_width = width;
        si->lfb_height = height;
        si->lfb_base = fb_base;
-       si->lfb_size = fb_size;
        si->pages = 1;
 
        if (pixel_format == PIXEL_RGB_RESERVED_8BIT_PER_COLOR) {
@@ -379,6 +378,8 @@ static efi_status_t setup_gop(struct screen_info *si, efi_guid_t *proto,
                si->rsvd_pos = 0;
        }
 
+       si->lfb_size = si->lfb_linelength * si->lfb_height;
+
        si->capabilities |= VIDEO_CAPABILITY_SKIP_QUIRKS;
 
 free_handle: