x86: video: Allow video ROM execution to fall back to the other method

If the BIOS emulator is not available, allow use of native execution if
available, and vice versa. This can be controlled by the caller.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>

arch/x86/cpu/ivybridge/gma.c

@@ -758,7 +758,8 @@ int gma_func0_init(pci_dev_t dev, struct pci_controller *hose,
 
 #ifdef CONFIG_VIDEO
 	start = get_timer(0);
-	ret = pci_run_vga_bios(dev, int15_handler, false);
+	ret = pci_run_vga_bios(dev, int15_handler, PCI_ROM_USE_NATIVE |
+			       PCI_ROM_ALLOW_FALLBACK);
 	debug("BIOS ran in %lums\n", get_timer(start));
 #endif
 	/* Post VBIOS init */

drivers/pci/pci_rom.c

@@ -228,11 +228,12 @@ int vbe_get_video_info(struct graphic_device *gdev)
 #endif
 }
 
-int pci_run_vga_bios(pci_dev_t dev, int (*int15_handler)(void), bool emulate)
+int pci_run_vga_bios(pci_dev_t dev, int (*int15_handler)(void), int exec_method)
 {
 	struct pci_rom_header *rom, *ram;
 	int vesa_mode = -1;
 	uint16_t class;
+	bool emulate;
 	int ret;
 
 	/* Only execute VGA ROMs */
@@ -262,6 +263,29 @@ int pci_run_vga_bios(pci_dev_t dev, int (*int15_handler)(void), bool emulate)
 	vesa_mode = CONFIG_FRAMEBUFFER_VESA_MODE;
 #endif
 	debug("Selected vesa mode %#x\n", vesa_mode);
+
+	if (exec_method & PCI_ROM_USE_NATIVE) {
+#ifdef CONFIG_X86
+		emulate = false;
+#else
+		if (!(exec_method & PCI_ROM_ALLOW_FALLBACK)) {
+			printf("BIOS native execution is only available on x86\n");
+			return -ENOSYS;
+		}
+		emulate = true;
+#endif
+	} else {
+#ifdef CONFIG_BIOSEMU
+		emulate = true;
+#else
+		if (!(exec_method & PCI_ROM_ALLOW_FALLBACK)) {
+			printf("BIOS emulation not available - see CONFIG_BIOSEMU\n");
+			return -ENOSYS;
+		}
+		emulate = false;
+#endif
+	}
+
 	if (emulate) {
 #ifdef CONFIG_BIOSEMU
 		BE_VGAInfo *info;
@@ -274,9 +298,6 @@ int pci_run_vga_bios(pci_dev_t dev, int (*int15_handler)(void), bool emulate)
 				  vesa_mode, &mode_info);
 		if (ret)
 			return ret;
-#else
-		printf("BIOS emulation not available - see CONFIG_BIOSEMU\n");
-		return -ENOSYS;
 #endif
 	} else {
 #ifdef CONFIG_X86
@@ -284,9 +305,6 @@ int pci_run_vga_bios(pci_dev_t dev, int (*int15_handler)(void), bool emulate)
 
 		bios_run_on_x86(dev, (unsigned long)ram, vesa_mode,
 				&mode_info);
-#else
-		printf("BIOS native execution is only available on x86\n");
-		return -ENOSYS;
 #endif
 	}
 	debug("Final vesa mode %#x\n", mode_info.video_mode);

drivers/video/vesa_fb.c

@@ -42,8 +42,8 @@ void *video_hw_init(void)
 			printf("no card detected\n");
 			return NULL;
 		}
-		printf("bdf %x\n", dev);
-		ret = pci_run_vga_bios(dev, NULL, true);
+		ret = pci_run_vga_bios(dev, NULL, PCI_ROM_USE_NATIVE |
+				       PCI_ROM_ALLOW_FALLBACK);
 		if (ret) {
 			printf("failed to run video BIOS: %d\n", ret);
 			return NULL;
@@ -59,7 +59,7 @@ void *video_hw_init(void)
 	sprintf(gdev->modeIdent, "%dx%dx%d", gdev->winSizeX, gdev->winSizeY,
 		bits_per_pixel);
 	printf("%s\n", gdev->modeIdent);
-	debug("Framex buffer at %x\n", gdev->pciBase);
+	debug("Frame buffer at %x\n", gdev->pciBase);
 
 	return (void *)gdev;
 }

include/pci_rom.h

@@ -33,14 +33,25 @@ struct pci_rom_data {
 	uint16_t reserved_2;
 };
 
+/*
+ * Determines which execution method is used and whether we allow falling back
+ * to the other if the requested method is not available.
+ */
+enum pci_rom_emul {
+	PCI_ROM_EMULATE		= 0 << 0,
+	PCI_ROM_USE_NATIVE	= 1 << 0,
+	PCI_ROM_ALLOW_FALLBACK	= 1 << 1,
+};
+
  /**
  * pci_run_vga_bios() - Run the VGA BIOS in an x86 PC
  *
  * @dev:	Video device containing the BIOS
  * @int15_handler:	Function to call to handle int 0x15
- * @emulate:	true to use the x86 emulator, false to run native
+ * @exec_method:	flags from enum pci_rom_emul
  */
-int pci_run_vga_bios(pci_dev_t dev, int (*int15_handler)(void), bool emulate);
+int pci_run_vga_bios(pci_dev_t dev, int (*int15_handler)(void),
+		     int exec_method);
 
 /**
  * board_map_oprom_vendev() - map several PCI IDs to the one the ROM expects