efi/libstub: Move Graphics Output Protocol handling to generic code

The Graphics Output Protocol code executes in the stub, so create a generic
version based on the x86 version in libstub so that we can move other archs
to it in subsequent patches. The new source file gop.c is added to the
libstub build for all architectures, but only wired up for x86.

Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Matt Fleming <matt@codeblueprint.co.uk>
Cc: Borislav Petkov <bp@alien8.de>
Cc: David Herrmann <dh.herrmann@gmail.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Peter Jones <pjones@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Will Deacon <will.deacon@arm.com>
Cc: linux-efi@vger.kernel.org
Link: http://lkml.kernel.org/r/1461614832-17633-18-git-send-email-matt@codeblueprint.co.uk
Signed-off-by: Ingo Molnar <mingo@kernel.org>

2 files changed, 355 insertions, 1 deletions

diff --git a/drivers/firmware/efi/libstub/Makefile b/drivers/firmware/efi/libstub/Makefile
index da99bbb74aeb..c06945160a41 100644
--- a/drivers/firmware/efi/libstub/Makefile
+++ b/drivers/firmware/efi/libstub/Makefile
@@ -28,7 +28,7 @@ OBJECT_FILES_NON_STANDARD	:= y
 # Prevents link failures: __sanitizer_cov_trace_pc() is not linked in.
 KCOV_INSTRUMENT			:= n
 
-lib-y				:= efi-stub-helper.o
+lib-y				:= efi-stub-helper.o gop.o
 
 # include the stub's generic dependencies from lib/ when building for ARM/arm64
 arm-deps := fdt_rw.c fdt_ro.c fdt_wip.c fdt.c fdt_empty_tree.c fdt_sw.c sort.c
diff --git a/drivers/firmware/efi/libstub/gop.c b/drivers/firmware/efi/libstub/gop.c
new file mode 100644
index 000000000000..932742e4cf23
--- /dev/null
+++ b/drivers/firmware/efi/libstub/gop.c
@@ -0,0 +1,354 @@
+/* -----------------------------------------------------------------------
+ *
+ *   Copyright 2011 Intel Corporation; author Matt Fleming
+ *
+ *   This file is part of the Linux kernel, and is made available under
+ *   the terms of the GNU General Public License version 2.
+ *
+ * ----------------------------------------------------------------------- */
+
+#include <linux/efi.h>
+#include <linux/screen_info.h>
+#include <asm/efi.h>
+#include <asm/setup.h>
+
+static void find_bits(unsigned long mask, u8 *pos, u8 *size)
+{
+	u8 first, len;
+
+	first = 0;
+	len = 0;
+
+	if (mask) {
+		while (!(mask & 0x1)) {
+			mask = mask >> 1;
+			first++;
+		}
+
+		while (mask & 0x1) {
+			mask = mask >> 1;
+			len++;
+		}
+	}
+
+	*pos = first;
+	*size = len;
+}
+
+static void
+setup_pixel_info(struct screen_info *si, u32 pixels_per_scan_line,
+		 struct efi_pixel_bitmask pixel_info, int pixel_format)
+{
+	if (pixel_format == PIXEL_RGB_RESERVED_8BIT_PER_COLOR) {
+		si->lfb_depth = 32;
+		si->lfb_linelength = pixels_per_scan_line * 4;
+		si->red_size = 8;
+		si->red_pos = 0;
+		si->green_size = 8;
+		si->green_pos = 8;
+		si->blue_size = 8;
+		si->blue_pos = 16;
+		si->rsvd_size = 8;
+		si->rsvd_pos = 24;
+	} else if (pixel_format == PIXEL_BGR_RESERVED_8BIT_PER_COLOR) {
+		si->lfb_depth = 32;
+		si->lfb_linelength = pixels_per_scan_line * 4;
+		si->red_size = 8;
+		si->red_pos = 16;
+		si->green_size = 8;
+		si->green_pos = 8;
+		si->blue_size = 8;
+		si->blue_pos = 0;
+		si->rsvd_size = 8;
+		si->rsvd_pos = 24;
+	} else if (pixel_format == PIXEL_BIT_MASK) {
+		find_bits(pixel_info.red_mask, &si->red_pos, &si->red_size);
+		find_bits(pixel_info.green_mask, &si->green_pos,
+			  &si->green_size);
+		find_bits(pixel_info.blue_mask, &si->blue_pos, &si->blue_size);
+		find_bits(pixel_info.reserved_mask, &si->rsvd_pos,
+			  &si->rsvd_size);
+		si->lfb_depth = si->red_size + si->green_size +
+			si->blue_size + si->rsvd_size;
+		si->lfb_linelength = (pixels_per_scan_line * si->lfb_depth) / 8;
+	} else {
+		si->lfb_depth = 4;
+		si->lfb_linelength = si->lfb_width / 2;
+		si->red_size = 0;
+		si->red_pos = 0;
+		si->green_size = 0;
+		si->green_pos = 0;
+		si->blue_size = 0;
+		si->blue_pos = 0;
+		si->rsvd_size = 0;
+		si->rsvd_pos = 0;
+	}
+}
+
+static efi_status_t
+__gop_query32(efi_system_table_t *sys_table_arg,
+	      struct efi_graphics_output_protocol_32 *gop32,
+	      struct efi_graphics_output_mode_info **info,
+	      unsigned long *size, u64 *fb_base)
+{
+	struct efi_graphics_output_protocol_mode_32 *mode;
+	efi_graphics_output_protocol_query_mode query_mode;
+	efi_status_t status;
+	unsigned long m;
+
+	m = gop32->mode;
+	mode = (struct efi_graphics_output_protocol_mode_32 *)m;
+	query_mode = (void *)(unsigned long)gop32->query_mode;
+
+	status = __efi_call_early(query_mode, (void *)gop32, mode->mode, size,
+				  info);
+	if (status != EFI_SUCCESS)
+		return status;
+
+	*fb_base = mode->frame_buffer_base;
+	return status;
+}
+
+static efi_status_t
+setup_gop32(efi_system_table_t *sys_table_arg, struct screen_info *si,
+            efi_guid_t *proto, unsigned long size, void **gop_handle)
+{
+	struct efi_graphics_output_protocol_32 *gop32, *first_gop;
+	unsigned long nr_gops;
+	u16 width, height;
+	u32 pixels_per_scan_line;
+	u32 ext_lfb_base;
+	u64 fb_base;
+	struct efi_pixel_bitmask pixel_info;
+	int pixel_format;
+	efi_status_t status = EFI_NOT_FOUND;
+	u32 *handles = (u32 *)(unsigned long)gop_handle;
+	int i;
+
+	first_gop = NULL;
+	gop32 = NULL;
+
+	nr_gops = size / sizeof(u32);
+	for (i = 0; i < nr_gops; i++) {
+		struct efi_graphics_output_mode_info *info = NULL;
+		efi_guid_t conout_proto = EFI_CONSOLE_OUT_DEVICE_GUID;
+		bool conout_found = false;
+		void *dummy = NULL;
+		efi_handle_t h = (efi_handle_t)(unsigned long)handles[i];
+		u64 current_fb_base;
+
+		status = efi_call_early(handle_protocol, h,
+					proto, (void **)&gop32);
+		if (status != EFI_SUCCESS)
+			continue;
+
+		status = efi_call_early(handle_protocol, h,
+					&conout_proto, &dummy);
+		if (status == EFI_SUCCESS)
+			conout_found = true;
+
+		status = __gop_query32(sys_table_arg, gop32, &info, &size,
+				       &current_fb_base);
+		if (status == EFI_SUCCESS && (!first_gop || conout_found)) {
+			/*
+			 * Systems that use the UEFI Console Splitter may
+			 * provide multiple GOP devices, not all of which are
+			 * backed by real hardware. The workaround is to search
+			 * for a GOP implementing the ConOut protocol, and if
+			 * one isn't found, to just fall back to the first GOP.
+			 */
+			width = info->horizontal_resolution;
+			height = info->vertical_resolution;
+			pixel_format = info->pixel_format;
+			pixel_info = info->pixel_information;
+			pixels_per_scan_line = info->pixels_per_scan_line;
+			fb_base = current_fb_base;
+
+			/*
+			 * Once we've found a GOP supporting ConOut,
+			 * don't bother looking any further.
+			 */
+			first_gop = gop32;
+			if (conout_found)
+				break;
+		}
+	}
+
+	/* Did we find any GOPs? */
+	if (!first_gop)
+		goto out;
+
+	/* EFI framebuffer */
+	si->orig_video_isVGA = VIDEO_TYPE_EFI;
+
+	si->lfb_width = width;
+	si->lfb_height = height;
+	si->lfb_base = fb_base;
+
+	ext_lfb_base = (u64)(unsigned long)fb_base >> 32;
+	if (ext_lfb_base) {
+		si->capabilities |= VIDEO_CAPABILITY_64BIT_BASE;
+		si->ext_lfb_base = ext_lfb_base;
+	}
+
+	si->pages = 1;
+
+	setup_pixel_info(si, pixels_per_scan_line, pixel_info, pixel_format);
+
+	si->lfb_size = si->lfb_linelength * si->lfb_height;
+
+	si->capabilities |= VIDEO_CAPABILITY_SKIP_QUIRKS;
+out:
+	return status;
+}
+
+static efi_status_t
+__gop_query64(efi_system_table_t *sys_table_arg,
+	      struct efi_graphics_output_protocol_64 *gop64,
+	      struct efi_graphics_output_mode_info **info,
+	      unsigned long *size, u64 *fb_base)
+{
+	struct efi_graphics_output_protocol_mode_64 *mode;
+	efi_graphics_output_protocol_query_mode query_mode;
+	efi_status_t status;
+	unsigned long m;
+
+	m = gop64->mode;
+	mode = (struct efi_graphics_output_protocol_mode_64 *)m;
+	query_mode = (void *)(unsigned long)gop64->query_mode;
+
+	status = __efi_call_early(query_mode, (void *)gop64, mode->mode, size,
+				  info);
+	if (status != EFI_SUCCESS)
+		return status;
+
+	*fb_base = mode->frame_buffer_base;
+	return status;
+}
+
+static efi_status_t
+setup_gop64(efi_system_table_t *sys_table_arg, struct screen_info *si,
+	    efi_guid_t *proto, unsigned long size, void **gop_handle)
+{
+	struct efi_graphics_output_protocol_64 *gop64, *first_gop;
+	unsigned long nr_gops;
+	u16 width, height;
+	u32 pixels_per_scan_line;
+	u32 ext_lfb_base;
+	u64 fb_base;
+	struct efi_pixel_bitmask pixel_info;
+	int pixel_format;
+	efi_status_t status = EFI_NOT_FOUND;
+	u64 *handles = (u64 *)(unsigned long)gop_handle;
+	int i;
+
+	first_gop = NULL;
+	gop64 = NULL;
+
+	nr_gops = size / sizeof(u64);
+	for (i = 0; i < nr_gops; i++) {
+		struct efi_graphics_output_mode_info *info = NULL;
+		efi_guid_t conout_proto = EFI_CONSOLE_OUT_DEVICE_GUID;
+		bool conout_found = false;
+		void *dummy = NULL;
+		efi_handle_t h = (efi_handle_t)(unsigned long)handles[i];
+		u64 current_fb_base;
+
+		status = efi_call_early(handle_protocol, h,
+					proto, (void **)&gop64);
+		if (status != EFI_SUCCESS)
+			continue;
+
+		status = efi_call_early(handle_protocol, h,
+					&conout_proto, &dummy);
+		if (status == EFI_SUCCESS)
+			conout_found = true;
+
+		status = __gop_query64(sys_table_arg, gop64, &info, &size,
+				       &current_fb_base);
+		if (status == EFI_SUCCESS && (!first_gop || conout_found)) {
+			/*
+			 * Systems that use the UEFI Console Splitter may
+			 * provide multiple GOP devices, not all of which are
+			 * backed by real hardware. The workaround is to search
+			 * for a GOP implementing the ConOut protocol, and if
+			 * one isn't found, to just fall back to the first GOP.
+			 */
+			width = info->horizontal_resolution;
+			height = info->vertical_resolution;
+			pixel_format = info->pixel_format;
+			pixel_info = info->pixel_information;
+			pixels_per_scan_line = info->pixels_per_scan_line;
+			fb_base = current_fb_base;
+
+			/*
+			 * Once we've found a GOP supporting ConOut,
+			 * don't bother looking any further.
+			 */
+			first_gop = gop64;
+			if (conout_found)
+				break;
+		}
+	}
+
+	/* Did we find any GOPs? */
+	if (!first_gop)
+		goto out;
+
+	/* EFI framebuffer */
+	si->orig_video_isVGA = VIDEO_TYPE_EFI;
+
+	si->lfb_width = width;
+	si->lfb_height = height;
+	si->lfb_base = fb_base;
+
+	ext_lfb_base = (u64)(unsigned long)fb_base >> 32;
+	if (ext_lfb_base) {
+		si->capabilities |= VIDEO_CAPABILITY_64BIT_BASE;
+		si->ext_lfb_base = ext_lfb_base;
+	}
+
+	si->pages = 1;
+
+	setup_pixel_info(si, pixels_per_scan_line, pixel_info, pixel_format);
+
+	si->lfb_size = si->lfb_linelength * si->lfb_height;
+
+	si->capabilities |= VIDEO_CAPABILITY_SKIP_QUIRKS;
+out:
+	return status;
+}
+
+/*
+ * See if we have Graphics Output Protocol
+ */
+efi_status_t efi_setup_gop(efi_system_table_t *sys_table_arg,
+			   struct screen_info *si, efi_guid_t *proto,
+			   unsigned long size)
+{
+	efi_status_t status;
+	void **gop_handle = NULL;
+
+	status = efi_call_early(allocate_pool, EFI_LOADER_DATA,
+				size, (void **)&gop_handle);
+	if (status != EFI_SUCCESS)
+		return status;
+
+	status = efi_call_early(locate_handle,
+				EFI_LOCATE_BY_PROTOCOL,
+				proto, NULL, &size, gop_handle);
+	if (status != EFI_SUCCESS)
+		goto free_handle;
+
+	if (efi_is_64bit()) {
+		status = setup_gop64(sys_table_arg, si, proto, size,
+				     gop_handle);
+	} else {
+		status = setup_gop32(sys_table_arg, si, proto, size,
+				     gop_handle);
+	}
+
+free_handle:
+	efi_call_early(free_pool, gop_handle);
+	return status;
+}