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https://github.com/torvalds/linux
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a483fcab38
Starting with ACPI 6.2 bits 1 and 2 of the BGRT status field are no longer reserved. These bits are now used to indicate if the image needs to be rotated before being displayed. The first device using these bits has now shown up (the GPD MicroPC) and the reserved bits check causes us to reject the valid BGRT table on this device. Rather then changing the reserved bits check, allowing only the 2 new bits, instead just completely remove it so that we do not end up with a similar problem when more bits are added in the future. Signed-off-by: Hans de Goede <hdegoede@redhat.com> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
84 lines
2 KiB
C
84 lines
2 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/*
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* Copyright 2012 Intel Corporation
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* Author: Josh Triplett <josh@joshtriplett.org>
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*
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* Based on the bgrt driver:
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* Copyright 2012 Red Hat, Inc <mjg@redhat.com>
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* Author: Matthew Garrett
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*/
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#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
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#include <linux/kernel.h>
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#include <linux/init.h>
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#include <linux/acpi.h>
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#include <linux/efi.h>
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#include <linux/efi-bgrt.h>
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struct acpi_table_bgrt bgrt_tab;
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size_t bgrt_image_size;
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struct bmp_header {
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u16 id;
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u32 size;
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} __packed;
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void __init efi_bgrt_init(struct acpi_table_header *table)
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{
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void *image;
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struct bmp_header bmp_header;
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struct acpi_table_bgrt *bgrt = &bgrt_tab;
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if (acpi_disabled)
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return;
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if (!efi_enabled(EFI_MEMMAP))
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return;
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if (table->length < sizeof(bgrt_tab)) {
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pr_notice("Ignoring BGRT: invalid length %u (expected %zu)\n",
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table->length, sizeof(bgrt_tab));
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return;
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}
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*bgrt = *(struct acpi_table_bgrt *)table;
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if (bgrt->version != 1) {
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pr_notice("Ignoring BGRT: invalid version %u (expected 1)\n",
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bgrt->version);
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goto out;
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}
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if (bgrt->image_type != 0) {
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pr_notice("Ignoring BGRT: invalid image type %u (expected 0)\n",
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bgrt->image_type);
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goto out;
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}
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if (!bgrt->image_address) {
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pr_notice("Ignoring BGRT: null image address\n");
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goto out;
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}
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if (efi_mem_type(bgrt->image_address) != EFI_BOOT_SERVICES_DATA) {
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pr_notice("Ignoring BGRT: invalid image address\n");
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goto out;
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}
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image = early_memremap(bgrt->image_address, sizeof(bmp_header));
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if (!image) {
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pr_notice("Ignoring BGRT: failed to map image header memory\n");
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goto out;
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}
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memcpy(&bmp_header, image, sizeof(bmp_header));
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early_memunmap(image, sizeof(bmp_header));
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if (bmp_header.id != 0x4d42) {
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pr_notice("Ignoring BGRT: Incorrect BMP magic number 0x%x (expected 0x4d42)\n",
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bmp_header.id);
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goto out;
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}
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bgrt_image_size = bmp_header.size;
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efi_mem_reserve(bgrt->image_address, bgrt_image_size);
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return;
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out:
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memset(bgrt, 0, sizeof(bgrt_tab));
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}
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