drivers/firmware/efi/arm-init.c - linux - Git at Google

 /*
  * Extensible Firmware Interface
  *
  * Based on Extensible Firmware Interface Specification version 2.4
  *
  * Copyright (C) 2013 - 2015 Linaro Ltd.
  *
  * 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.
  *
  */

 #define pr_fmt(fmt)	"efi: " fmt

 #include <linux/efi.h>
 #include <linux/init.h>
 #include <linux/memblock.h>
 #include <linux/mm_types.h>
 #include <linux/of.h>
 #include <linux/of_fdt.h>
 #include <linux/platform_device.h>
 #include <linux/screen_info.h>

 #include <asm/efi.h>

 u64 efi_system_table;

 static int __init is_memory(efi_memory_desc_t *md)
 {
 	if (md->attribute & (EFI_MEMORY_WB|EFI_MEMORY_WT|EFI_MEMORY_WC))
 		return 1;
 	return 0;
 }

 /*
  * Translate a EFI virtual address into a physical address: this is necessary,
  * as some data members of the EFI system table are virtually remapped after
  * SetVirtualAddressMap() has been called.
  */
 static phys_addr_t efi_to_phys(unsigned long addr)
 {
 	efi_memory_desc_t *md;

 	for_each_efi_memory_desc(md) {
 		if (!(md->attribute & EFI_MEMORY_RUNTIME))
 			continue;
 		if (md->virt_addr == 0)
 			/* no virtual mapping has been installed by the stub */
 			break;
 		if (md->virt_addr <= addr &&
 		    (addr - md->virt_addr) < (md->num_pages << EFI_PAGE_SHIFT))
 			return md->phys_addr + addr - md->virt_addr;
 	}
 	return addr;
 }

 static __initdata unsigned long screen_info_table = EFI_INVALID_TABLE_ADDR;

 static __initdata efi_config_table_type_t arch_tables[] = {
 	{LINUX_EFI_ARM_SCREEN_INFO_TABLE_GUID, NULL, &screen_info_table},
 	{NULL_GUID, NULL, NULL}
 };

 static void __init init_screen_info(void)
 {
 	struct screen_info *si;

 	if (screen_info_table != EFI_INVALID_TABLE_ADDR) {
 		si = early_memremap_ro(screen_info_table, sizeof(*si));
 		if (!si) {
 			pr_err("Could not map screen_info config table\n");
 			return;
 		}
 		screen_info = *si;
 		early_memunmap(si, sizeof(*si));

 		/* dummycon on ARM needs non-zero values for columns/lines */
 		screen_info.orig_video_cols = 80;
 		screen_info.orig_video_lines = 25;
 	}

 	if (screen_info.orig_video_isVGA == VIDEO_TYPE_EFI &&
 	    memblock_is_map_memory(screen_info.lfb_base))
 		memblock_mark_nomap(screen_info.lfb_base, screen_info.lfb_size);
 }

 static int __init uefi_init(void)
 {
 	efi_char16_t *c16;
 	void *config_tables;
 	size_t table_size;
 	char vendor[100] = "unknown";
 	int i, retval;

 	efi.systab = early_memremap_ro(efi_system_table,
 				       sizeof(efi_system_table_t));
 	if (efi.systab == NULL) {
 		pr_warn("Unable to map EFI system table.\n");
 		return -ENOMEM;
 	}

 	set_bit(EFI_BOOT, &efi.flags);
 	if (IS_ENABLED(CONFIG_64BIT))
 		set_bit(EFI_64BIT, &efi.flags);

 	/*
 	 * Verify the EFI Table
 	 */
 	if (efi.systab->hdr.signature != EFI_SYSTEM_TABLE_SIGNATURE) {
 		pr_err("System table signature incorrect\n");
 		retval = -EINVAL;
 		goto out;
 	}
 	if ((efi.systab->hdr.revision >> 16) < 2)
 		pr_warn("Warning: EFI system table version %d.%02d, expected 2.00 or greater\n",
 			efi.systab->hdr.revision >> 16,
 			efi.systab->hdr.revision & 0xffff);

 	efi.runtime_version = efi.systab->hdr.revision;

 	/* Show what we know for posterity */
 	c16 = early_memremap_ro(efi_to_phys(efi.systab->fw_vendor),
 				sizeof(vendor) * sizeof(efi_char16_t));
 	if (c16) {
 		for (i = 0; i < (int) sizeof(vendor) - 1 && *c16; ++i)
 			vendor[i] = c16[i];
 		vendor[i] = '\0';
 		early_memunmap(c16, sizeof(vendor) * sizeof(efi_char16_t));
 	}

 	pr_info("EFI v%u.%.02u by %s\n",
 		efi.systab->hdr.revision >> 16,
 		efi.systab->hdr.revision & 0xffff, vendor);

 	table_size = sizeof(efi_config_table_64_t) * efi.systab->nr_tables;
 	config_tables = early_memremap_ro(efi_to_phys(efi.systab->tables),
 					  table_size);
 	if (config_tables == NULL) {
 		pr_warn("Unable to map EFI config table array.\n");
 		retval = -ENOMEM;
 		goto out;
 	}
 	retval = efi_config_parse_tables(config_tables, efi.systab->nr_tables,
 					 sizeof(efi_config_table_t),
 					 arch_tables);

 	early_memunmap(config_tables, table_size);
 out:
 	early_memunmap(efi.systab,  sizeof(efi_system_table_t));
 	return retval;
 }

 /*
  * Return true for regions that can be used as System RAM.
  */
 static __init int is_usable_memory(efi_memory_desc_t *md)
 {
 	switch (md->type) {
 	case EFI_LOADER_CODE:
 	case EFI_LOADER_DATA:
 	case EFI_BOOT_SERVICES_CODE:
 	case EFI_BOOT_SERVICES_DATA:
 	case EFI_CONVENTIONAL_MEMORY:
 	case EFI_PERSISTENT_MEMORY:
 		/*
 		 * According to the spec, these regions are no longer reserved
 		 * after calling ExitBootServices(). However, we can only use
 		 * them as System RAM if they can be mapped writeback cacheable.
 		 */
 		return (md->attribute & EFI_MEMORY_WB);
 	default:
 		break;
 	}
 	return false;
 }

 static __init void reserve_regions(void)
 {
 	efi_memory_desc_t *md;
 	u64 paddr, npages, size;

 	if (efi_enabled(EFI_DBG))
 		pr_info("Processing EFI memory map:\n");

 	/*
 	 * Discard memblocks discovered so far: if there are any at this
 	 * point, they originate from memory nodes in the DT, and UEFI
 	 * uses its own memory map instead.
 	 */
 	memblock_dump_all();
 	memblock_remove(0, (phys_addr_t)ULLONG_MAX);

 	for_each_efi_memory_desc(md) {
 		paddr = md->phys_addr;
 		npages = md->num_pages;

 		if (efi_enabled(EFI_DBG)) {
 			char buf[64];

 			pr_info("  0x%012llx-0x%012llx %s\n",
 				paddr, paddr + (npages << EFI_PAGE_SHIFT) - 1,
 				efi_md_typeattr_format(buf, sizeof(buf), md));
 		}

 		memrange_efi_to_native(&paddr, &npages);
 		size = npages << PAGE_SHIFT;

 		if (is_memory(md)) {
 			early_init_dt_add_memory_arch(paddr, size);

 			if (!is_usable_memory(md))
 				memblock_mark_nomap(paddr, size);
 		}
 	}
 }

 void __init efi_init(void)
 {
 	struct efi_memory_map_data data;
 	struct efi_fdt_params params;

 	/* Grab UEFI information placed in FDT by stub */
 	if (!efi_get_fdt_params(&params))
 		return;

 	efi_system_table = params.system_table;

 	data.desc_version = params.desc_ver;
 	data.desc_size = params.desc_size;
 	data.size = params.mmap_size;
 	data.phys_map = params.mmap;

 	if (efi_memmap_init_early(&data) < 0) {
 		/*
 		* If we are booting via UEFI, the UEFI memory map is the only
 		* description of memory we have, so there is little point in
 		* proceeding if we cannot access it.
 		*/
 		panic("Unable to map EFI memory map.\n");
 	}

 	WARN(efi.memmap.desc_version != 1,
 	     "Unexpected EFI_MEMORY_DESCRIPTOR version %ld",
 	      efi.memmap.desc_version);

 	if (uefi_init() < 0)
 		return;

 	reserve_regions();
 	efi_memattr_init();
 	efi_esrt_init();
 	efi_memmap_unmap();

 	memblock_reserve(params.mmap & PAGE_MASK,
 			 PAGE_ALIGN(params.mmap_size +
 				    (params.mmap & ~PAGE_MASK)));

 	init_screen_info();
 }

 static int __init register_gop_device(void)
 {
 	void *pd;

 	if (screen_info.orig_video_isVGA != VIDEO_TYPE_EFI)
 		return 0;

 	pd = platform_device_register_data(NULL, "efi-framebuffer", 0,
 					   &screen_info, sizeof(screen_info));
 	return PTR_ERR_OR_ZERO(pd);
 }
 subsys_initcall(register_gop_device);
	/*
	* Extensible Firmware Interface
	*
	* Based on Extensible Firmware Interface Specification version 2.4
	*
	* Copyright (C) 2013 - 2015 Linaro Ltd.
	*
	* 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.
	*
	*/

	#define pr_fmt(fmt) "efi: " fmt

	#include <linux/efi.h>
	#include <linux/init.h>
	#include <linux/memblock.h>
	#include <linux/mm_types.h>
	#include <linux/of.h>
	#include <linux/of_fdt.h>
	#include <linux/platform_device.h>
	#include <linux/screen_info.h>

	#include <asm/efi.h>

	u64 efi_system_table;

	static int __init is_memory(efi_memory_desc_t *md)
	{
	if (md->attribute & (EFI_MEMORY_WB\|EFI_MEMORY_WT\|EFI_MEMORY_WC))
	return 1;
	return 0;
	}

	/*
	* Translate a EFI virtual address into a physical address: this is necessary,
	* as some data members of the EFI system table are virtually remapped after
	* SetVirtualAddressMap() has been called.
	*/
	static phys_addr_t efi_to_phys(unsigned long addr)
	{
	efi_memory_desc_t *md;

	for_each_efi_memory_desc(md) {
	if (!(md->attribute & EFI_MEMORY_RUNTIME))
	continue;
	if (md->virt_addr == 0)
	/* no virtual mapping has been installed by the stub */
	break;
	if (md->virt_addr <= addr &&
	(addr - md->virt_addr) < (md->num_pages << EFI_PAGE_SHIFT))
	return md->phys_addr + addr - md->virt_addr;
	}
	return addr;
	}

	static __initdata unsigned long screen_info_table = EFI_INVALID_TABLE_ADDR;

	static __initdata efi_config_table_type_t arch_tables[] = {
	{LINUX_EFI_ARM_SCREEN_INFO_TABLE_GUID, NULL, &screen_info_table},
	{NULL_GUID, NULL, NULL}
	};

	static void __init init_screen_info(void)
	{
	struct screen_info *si;

	if (screen_info_table != EFI_INVALID_TABLE_ADDR) {
	si = early_memremap_ro(screen_info_table, sizeof(*si));
	if (!si) {
	pr_err("Could not map screen_info config table\n");
	return;
	}
	screen_info = *si;
	early_memunmap(si, sizeof(*si));

	/* dummycon on ARM needs non-zero values for columns/lines */
	screen_info.orig_video_cols = 80;
	screen_info.orig_video_lines = 25;
	}

	if (screen_info.orig_video_isVGA == VIDEO_TYPE_EFI &&
	memblock_is_map_memory(screen_info.lfb_base))
	memblock_mark_nomap(screen_info.lfb_base, screen_info.lfb_size);
	}

	static int __init uefi_init(void)
	{
	efi_char16_t *c16;
	void *config_tables;
	size_t table_size;
	char vendor[100] = "unknown";
	int i, retval;

	efi.systab = early_memremap_ro(efi_system_table,
	sizeof(efi_system_table_t));
	if (efi.systab == NULL) {
	pr_warn("Unable to map EFI system table.\n");
	return -ENOMEM;
	}

	set_bit(EFI_BOOT, &efi.flags);
	if (IS_ENABLED(CONFIG_64BIT))
	set_bit(EFI_64BIT, &efi.flags);

	/*
	* Verify the EFI Table
	*/
	if (efi.systab->hdr.signature != EFI_SYSTEM_TABLE_SIGNATURE) {
	pr_err("System table signature incorrect\n");
	retval = -EINVAL;
	goto out;
	}
	if ((efi.systab->hdr.revision >> 16) < 2)
	pr_warn("Warning: EFI system table version %d.%02d, expected 2.00 or greater\n",
	efi.systab->hdr.revision >> 16,
	efi.systab->hdr.revision & 0xffff);

	efi.runtime_version = efi.systab->hdr.revision;

	/* Show what we know for posterity */
	c16 = early_memremap_ro(efi_to_phys(efi.systab->fw_vendor),
	sizeof(vendor) * sizeof(efi_char16_t));
	if (c16) {
	for (i = 0; i < (int) sizeof(vendor) - 1 && *c16; ++i)
	vendor[i] = c16[i];
	vendor[i] = '\0';
	early_memunmap(c16, sizeof(vendor) * sizeof(efi_char16_t));
	}

	pr_info("EFI v%u.%.02u by %s\n",
	efi.systab->hdr.revision >> 16,
	efi.systab->hdr.revision & 0xffff, vendor);

	table_size = sizeof(efi_config_table_64_t) * efi.systab->nr_tables;
	config_tables = early_memremap_ro(efi_to_phys(efi.systab->tables),
	table_size);
	if (config_tables == NULL) {
	pr_warn("Unable to map EFI config table array.\n");
	retval = -ENOMEM;
	goto out;
	}
	retval = efi_config_parse_tables(config_tables, efi.systab->nr_tables,
	sizeof(efi_config_table_t),
	arch_tables);

	early_memunmap(config_tables, table_size);
	out:
	early_memunmap(efi.systab, sizeof(efi_system_table_t));
	return retval;
	}

	/*
	* Return true for regions that can be used as System RAM.
	*/
	static __init int is_usable_memory(efi_memory_desc_t *md)
	{
	switch (md->type) {
	case EFI_LOADER_CODE:
	case EFI_LOADER_DATA:
	case EFI_BOOT_SERVICES_CODE:
	case EFI_BOOT_SERVICES_DATA:
	case EFI_CONVENTIONAL_MEMORY:
	case EFI_PERSISTENT_MEMORY:
	/*
	* According to the spec, these regions are no longer reserved
	* after calling ExitBootServices(). However, we can only use
	* them as System RAM if they can be mapped writeback cacheable.
	*/
	return (md->attribute & EFI_MEMORY_WB);
	default:
	break;
	}
	return false;
	}

	static __init void reserve_regions(void)
	{
	efi_memory_desc_t *md;
	u64 paddr, npages, size;

	if (efi_enabled(EFI_DBG))
	pr_info("Processing EFI memory map:\n");

	/*
	* Discard memblocks discovered so far: if there are any at this
	* point, they originate from memory nodes in the DT, and UEFI
	* uses its own memory map instead.
	*/
	memblock_dump_all();
	memblock_remove(0, (phys_addr_t)ULLONG_MAX);

	for_each_efi_memory_desc(md) {
	paddr = md->phys_addr;
	npages = md->num_pages;

	if (efi_enabled(EFI_DBG)) {
	char buf[64];

	pr_info(" 0x%012llx-0x%012llx %s\n",
	paddr, paddr + (npages << EFI_PAGE_SHIFT) - 1,
	efi_md_typeattr_format(buf, sizeof(buf), md));
	}

	memrange_efi_to_native(&paddr, &npages);
	size = npages << PAGE_SHIFT;

	if (is_memory(md)) {
	early_init_dt_add_memory_arch(paddr, size);

	if (!is_usable_memory(md))
	memblock_mark_nomap(paddr, size);
	}
	}
	}

	void __init efi_init(void)
	{
	struct efi_memory_map_data data;
	struct efi_fdt_params params;

	/* Grab UEFI information placed in FDT by stub */
	if (!efi_get_fdt_params(&params))
	return;

	efi_system_table = params.system_table;

	data.desc_version = params.desc_ver;
	data.desc_size = params.desc_size;
	data.size = params.mmap_size;
	data.phys_map = params.mmap;

	if (efi_memmap_init_early(&data) < 0) {
	/*
	* If we are booting via UEFI, the UEFI memory map is the only
	* description of memory we have, so there is little point in
	* proceeding if we cannot access it.
	*/
	panic("Unable to map EFI memory map.\n");
	}

	WARN(efi.memmap.desc_version != 1,
	"Unexpected EFI_MEMORY_DESCRIPTOR version %ld",
	efi.memmap.desc_version);

	if (uefi_init() < 0)
	return;

	reserve_regions();
	efi_memattr_init();
	efi_esrt_init();
	efi_memmap_unmap();

	memblock_reserve(params.mmap & PAGE_MASK,
	PAGE_ALIGN(params.mmap_size +
	(params.mmap & ~PAGE_MASK)));

	init_screen_info();
	}

	static int __init register_gop_device(void)
	{
	void *pd;

	if (screen_info.orig_video_isVGA != VIDEO_TYPE_EFI)
	return 0;

	pd = platform_device_register_data(NULL, "efi-framebuffer", 0,
	&screen_info, sizeof(screen_info));
	return PTR_ERR_OR_ZERO(pd);
	}
	subsys_initcall(register_gop_device);