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

 // SPDX-License-Identifier: GPL-2.0
 /*
  * Extensible Firmware Interface
  *
  * Based on Extensible Firmware Interface Specification version 2.4
  *
  * Copyright (C) 2013 - 2015 Linaro Ltd.
  */

 #define pr_fmt(fmt)	"efi: " fmt

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

 #include <asm/efi.h>

 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 __init 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 const efi_config_table_type_t arch_tables[] __initconst = {
 	{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(u64 efi_system_table)
 {
 	efi_config_table_t *config_tables;
 	efi_system_table_t *systab;
 	size_t table_size;
 	int retval;

 	systab = early_memremap_ro(efi_system_table, sizeof(efi_system_table_t));
 	if (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);

 	retval = efi_systab_check_header(&systab->hdr, 2);
 	if (retval)
 		goto out;

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

 	efi_systab_report_header(&systab->hdr, efi_to_phys(systab->fw_vendor));

 	table_size = sizeof(efi_config_table_t) * systab->nr_tables;
 	config_tables = early_memremap_ro(efi_to_phys(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, systab->nr_tables,
 					 arch_tables);

 	early_memunmap(config_tables, table_size);
 out:
 	early_memunmap(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_ACPI_RECLAIM_MEMORY:
 	case EFI_BOOT_SERVICES_CODE:
 	case EFI_BOOT_SERVICES_DATA:
 	case EFI_CONVENTIONAL_MEMORY:
 	case EFI_PERSISTENT_MEMORY:
 		/*
 		 * Special purpose memory is 'soft reserved', which means it
 		 * is set aside initially, but can be hotplugged back in or
 		 * be assigned to the dax driver after boot.
 		 */
 		if (efi_soft_reserve_enabled() &&
 		    (md->attribute & EFI_MEMORY_SP))
 			return false;

 		/*
 		 * 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_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);

 			/* keep ACPI reclaim memory intact for kexec etc. */
 			if (md->type == EFI_ACPI_RECLAIM_MEMORY)
 				memblock_reserve(paddr, size);
 		}
 	}
 }

 void __init efi_init(void)
 {
 	struct efi_memory_map_data data;
 	u64 efi_system_table;

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

 	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(efi_system_table) < 0) {
 		efi_memmap_unmap();
 		return;
 	}

 	reserve_regions();
 	efi_esrt_init();

 	memblock_reserve(data.phys_map & PAGE_MASK,
 			 PAGE_ALIGN(data.size + (data.phys_map & ~PAGE_MASK)));

 	init_screen_info();

 	/* ARM does not permit early mappings to persist across paging_init() */
 	if (IS_ENABLED(CONFIG_ARM))
 		efi_memmap_unmap();
 }

 static bool efifb_overlaps_pci_range(const struct of_pci_range *range)
 {
 	u64 fb_base = screen_info.lfb_base;

 	if (screen_info.capabilities & VIDEO_CAPABILITY_64BIT_BASE)
 		fb_base |= (u64)(unsigned long)screen_info.ext_lfb_base << 32;

 	return fb_base >= range->cpu_addr &&
 	       fb_base < (range->cpu_addr + range->size);
 }

 static struct device_node *find_pci_overlap_node(void)
 {
 	struct device_node *np;

 	for_each_node_by_type(np, "pci") {
 		struct of_pci_range_parser parser;
 		struct of_pci_range range;
 		int err;

 		err = of_pci_range_parser_init(&parser, np);
 		if (err) {
 			pr_warn("of_pci_range_parser_init() failed: %d\n", err);
 			continue;
 		}

 		for_each_of_pci_range(&parser, &range)
 			if (efifb_overlaps_pci_range(&range))
 				return np;
 	}
 	return NULL;
 }

 /*
  * If the efifb framebuffer is backed by a PCI graphics controller, we have
  * to ensure that this relation is expressed using a device link when
  * running in DT mode, or the probe order may be reversed, resulting in a
  * resource reservation conflict on the memory window that the efifb
  * framebuffer steals from the PCIe host bridge.
  */
 static int efifb_add_links(const struct fwnode_handle *fwnode,
 			   struct device *dev)
 {
 	struct device_node *sup_np;
 	struct device *sup_dev;

 	sup_np = find_pci_overlap_node();

 	/*
 	 * If there's no PCI graphics controller backing the efifb, we are
 	 * done here.
 	 */
 	if (!sup_np)
 		return 0;

 	sup_dev = get_dev_from_fwnode(&sup_np->fwnode);
 	of_node_put(sup_np);

 	/*
 	 * Return -ENODEV if the PCI graphics controller device hasn't been
 	 * registered yet.  This ensures that efifb isn't allowed to probe
 	 * and this function is retried again when new devices are
 	 * registered.
 	 */
 	if (!sup_dev)
 		return -ENODEV;

 	/*
 	 * If this fails, retrying this function at a later point won't
 	 * change anything. So, don't return an error after this.
 	 */
 	if (!device_link_add(dev, sup_dev, fw_devlink_get_flags()))
 		dev_warn(dev, "device_link_add() failed\n");

 	put_device(sup_dev);

 	return 0;
 }

 static const struct fwnode_operations efifb_fwnode_ops = {
 	.add_links = efifb_add_links,
 };

 static struct fwnode_handle efifb_fwnode = {
 	.ops = &efifb_fwnode_ops,
 };

 static int __init register_gop_device(void)
 {
 	struct platform_device *pd;
 	int err;

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

 	pd = platform_device_alloc("efi-framebuffer", 0);
 	if (!pd)
 		return -ENOMEM;

 	if (IS_ENABLED(CONFIG_PCI))
 		pd->dev.fwnode = &efifb_fwnode;

 	err = platform_device_add_data(pd, &screen_info, sizeof(screen_info));
 	if (err)
 		return err;

 	return platform_device_add(pd);
 }
 subsys_initcall(register_gop_device);
	// SPDX-License-Identifier: GPL-2.0
	/*
	* Extensible Firmware Interface
	*
	* Based on Extensible Firmware Interface Specification version 2.4
	*
	* Copyright (C) 2013 - 2015 Linaro Ltd.
	*/

	#define pr_fmt(fmt) "efi: " fmt

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

	#include <asm/efi.h>

	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 __init 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 const efi_config_table_type_t arch_tables[] __initconst = {
	{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(u64 efi_system_table)
	{
	efi_config_table_t *config_tables;
	efi_system_table_t *systab;
	size_t table_size;
	int retval;

	systab = early_memremap_ro(efi_system_table, sizeof(efi_system_table_t));
	if (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);

	retval = efi_systab_check_header(&systab->hdr, 2);
	if (retval)
	goto out;

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

	efi_systab_report_header(&systab->hdr, efi_to_phys(systab->fw_vendor));

	table_size = sizeof(efi_config_table_t) * systab->nr_tables;
	config_tables = early_memremap_ro(efi_to_phys(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, systab->nr_tables,
	arch_tables);

	early_memunmap(config_tables, table_size);
	out:
	early_memunmap(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_ACPI_RECLAIM_MEMORY:
	case EFI_BOOT_SERVICES_CODE:
	case EFI_BOOT_SERVICES_DATA:
	case EFI_CONVENTIONAL_MEMORY:
	case EFI_PERSISTENT_MEMORY:
	/*
	* Special purpose memory is 'soft reserved', which means it
	* is set aside initially, but can be hotplugged back in or
	* be assigned to the dax driver after boot.
	*/
	if (efi_soft_reserve_enabled() &&
	(md->attribute & EFI_MEMORY_SP))
	return false;

	/*
	* 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_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);

	/* keep ACPI reclaim memory intact for kexec etc. */
	if (md->type == EFI_ACPI_RECLAIM_MEMORY)
	memblock_reserve(paddr, size);
	}
	}
	}

	void __init efi_init(void)
	{
	struct efi_memory_map_data data;
	u64 efi_system_table;

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

	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(efi_system_table) < 0) {
	efi_memmap_unmap();
	return;
	}

	reserve_regions();
	efi_esrt_init();

	memblock_reserve(data.phys_map & PAGE_MASK,
	PAGE_ALIGN(data.size + (data.phys_map & ~PAGE_MASK)));

	init_screen_info();

	/* ARM does not permit early mappings to persist across paging_init() */
	if (IS_ENABLED(CONFIG_ARM))
	efi_memmap_unmap();
	}

	static bool efifb_overlaps_pci_range(const struct of_pci_range *range)
	{
	u64 fb_base = screen_info.lfb_base;

	if (screen_info.capabilities & VIDEO_CAPABILITY_64BIT_BASE)
	fb_base \|= (u64)(unsigned long)screen_info.ext_lfb_base << 32;

	return fb_base >= range->cpu_addr &&
	fb_base < (range->cpu_addr + range->size);
	}

	static struct device_node *find_pci_overlap_node(void)
	{
	struct device_node *np;

	for_each_node_by_type(np, "pci") {
	struct of_pci_range_parser parser;
	struct of_pci_range range;
	int err;

	err = of_pci_range_parser_init(&parser, np);
	if (err) {
	pr_warn("of_pci_range_parser_init() failed: %d\n", err);
	continue;
	}

	for_each_of_pci_range(&parser, &range)
	if (efifb_overlaps_pci_range(&range))
	return np;
	}
	return NULL;
	}

	/*
	* If the efifb framebuffer is backed by a PCI graphics controller, we have
	* to ensure that this relation is expressed using a device link when
	* running in DT mode, or the probe order may be reversed, resulting in a
	* resource reservation conflict on the memory window that the efifb
	* framebuffer steals from the PCIe host bridge.
	*/
	static int efifb_add_links(const struct fwnode_handle *fwnode,
	struct device *dev)
	{
	struct device_node *sup_np;
	struct device *sup_dev;

	sup_np = find_pci_overlap_node();

	/*
	* If there's no PCI graphics controller backing the efifb, we are
	* done here.
	*/
	if (!sup_np)
	return 0;

	sup_dev = get_dev_from_fwnode(&sup_np->fwnode);
	of_node_put(sup_np);

	/*
	* Return -ENODEV if the PCI graphics controller device hasn't been
	* registered yet. This ensures that efifb isn't allowed to probe
	* and this function is retried again when new devices are
	* registered.
	*/
	if (!sup_dev)
	return -ENODEV;

	/*
	* If this fails, retrying this function at a later point won't
	* change anything. So, don't return an error after this.
	*/
	if (!device_link_add(dev, sup_dev, fw_devlink_get_flags()))
	dev_warn(dev, "device_link_add() failed\n");

	put_device(sup_dev);

	return 0;
	}

	static const struct fwnode_operations efifb_fwnode_ops = {
	.add_links = efifb_add_links,
	};

	static struct fwnode_handle efifb_fwnode = {
	.ops = &efifb_fwnode_ops,
	};

	static int __init register_gop_device(void)
	{
	struct platform_device *pd;
	int err;

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

	pd = platform_device_alloc("efi-framebuffer", 0);
	if (!pd)
	return -ENOMEM;

	if (IS_ENABLED(CONFIG_PCI))
	pd->dev.fwnode = &efifb_fwnode;

	err = platform_device_add_data(pd, &screen_info, sizeof(screen_info));
	if (err)
	return err;

	return platform_device_add(pd);
	}
	subsys_initcall(register_gop_device);