/* * Copyright 2012 Intel Corporation * Author: Josh Triplett <josh@joshtriplett.org> * * Based on the bgrt driver: * Copyright 2012 Red Hat, Inc <mjg@redhat.com> * Author: Matthew Garrett * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License version 2 as * published by the Free Software Foundation. */ #include <linux/kernel.h> #include <linux/init.h> #include <linux/acpi.h> #include <linux/efi.h> #include <linux/efi-bgrt.h> struct acpi_table_bgrt *bgrt_tab; void *__initdata bgrt_image; size_t __initdata bgrt_image_size; struct bmp_header { u16 id; u32 size; } __packed; void __init efi_bgrt_init(void) { acpi_status status; void __iomem *image; bool ioremapped = false; struct bmp_header bmp_header; if (acpi_disabled) return; status = acpi_get_table("BGRT", 0, (struct acpi_table_header **)&bgrt_tab); if (ACPI_FAILURE(status)) return; if (bgrt_tab->header.length < sizeof(*bgrt_tab)) { pr_err("Ignoring BGRT: invalid length %u (expected %zu)\n", bgrt_tab->header.length, sizeof(*bgrt_tab)); return; } if (bgrt_tab->version != 1) { pr_err("Ignoring BGRT: invalid version %u (expected 1)\n", bgrt_tab->version); return; } if (bgrt_tab->status != 1) { pr_err("Ignoring BGRT: invalid status %u (expected 1)\n", bgrt_tab->status); return; } if (bgrt_tab->image_type != 0) { pr_err("Ignoring BGRT: invalid image type %u (expected 0)\n", bgrt_tab->image_type); return; } if (!bgrt_tab->image_address) { pr_err("Ignoring BGRT: null image address\n"); return; } image = efi_lookup_mapped_addr(bgrt_tab->image_address); if (!image) { image = early_ioremap(bgrt_tab->image_address, sizeof(bmp_header)); ioremapped = true; if (!image) { pr_err("Ignoring BGRT: failed to map image header memory\n"); return; } } memcpy_fromio(&bmp_header, image, sizeof(bmp_header)); if (ioremapped) early_iounmap(image, sizeof(bmp_header)); bgrt_image_size = bmp_header.size; bgrt_image = kmalloc(bgrt_image_size, GFP_KERNEL | __GFP_NOWARN); if (!bgrt_image) { pr_err("Ignoring BGRT: failed to allocate memory for image (wanted %zu bytes)\n", bgrt_image_size); return; } if (ioremapped) { image = early_ioremap(bgrt_tab->image_address, bmp_header.size); if (!image) { pr_err("Ignoring BGRT: failed to map image memory\n"); kfree(bgrt_image); bgrt_image = NULL; return; } } memcpy_fromio(bgrt_image, image, bgrt_image_size); if (ioremapped) early_iounmap(image, bmp_header.size); }