// SPDX-License-Identifier: GPL-2.0/* * Common EFI memory map functions. */ #define pr_fmt(fmt) "efi: " fmt #include <linux/init.h>#include <linux/kernel.h>#include <linux/efi.h>#include <linux/io.h>#include <linux/memblock.h>#include <linux/slab.h> #include <asm/early_ioremap.h>#include <asm/efi.h> /** * __efi_memmap_init - Common code for mapping the EFI memory map * @data: EFI memory map data * * This function takes care of figuring out which function to use to * map the EFI memory map in efi.memmap based on how far into the boot * we are. * * During bootup EFI_MEMMAP_LATE in data->flags should be clear since we * only have access to the early_memremap*() functions as the vmalloc * space isn't setup.  Once the kernel is fully booted we can fallback * to the more robust memremap*() API. * * Returns: zero on success, a negative error code on failure. */int __init __efi_memmap_init(struct efi_memory_map_data *data){	struct efi_memory_map map;	phys_addr_t phys_map; 	phys_map = data->phys_map; 	if (data->flags & EFI_MEMMAP_LATE)		map.map = memremap(phys_map, data->size, MEMREMAP_WB);	else		map.map = early_memremap(phys_map, data->size); 	if (!map.map) {		pr_err("Could not map the memory map! phys_map=%pa, size=0x%lx\n",			&phys_map, data->size);		return -ENOMEM;	} 	map.phys_map = data->phys_map;	map.nr_map = data->size / data->desc_size;	map.map_end = map.map + data->size; 	map.desc_version = data->desc_version;	map.desc_size = data->desc_size;	map.flags = data->flags; 	set_bit(EFI_MEMMAP, &efi.flags); 	efi.memmap = map; 	return 0;} /** * efi_memmap_init_early - Map the EFI memory map data structure * @data: EFI memory map data * * Use early_memremap() to map the passed in EFI memory map and assign * it to efi.memmap. * * Returns: zero on success, a negative error code on failure. */int __init efi_memmap_init_early(struct efi_memory_map_data *data){	/* Cannot go backwards */	WARN_ON(efi.memmap.flags & EFI_MEMMAP_LATE); 	data->flags = 0;	return __efi_memmap_init(data);} void __init efi_memmap_unmap(void){	if (!efi_enabled(EFI_MEMMAP))		return; 	if (!(efi.memmap.flags & EFI_MEMMAP_LATE)) {		unsigned long size; 		size = efi.memmap.desc_size * efi.memmap.nr_map;		early_memunmap(efi.memmap.map, size);	} else {		memunmap(efi.memmap.map);	} 	efi.memmap.map = NULL;	clear_bit(EFI_MEMMAP, &efi.flags);} /** * efi_memmap_init_late - Map efi.memmap with memremap() * @addr: Physical address of the new EFI memory map * @size: Size in bytes of the new EFI memory map * * Setup a mapping of the EFI memory map using ioremap_cache(). This * function should only be called once the vmalloc space has been * setup and is therefore not suitable for calling during early EFI * initialise, e.g. in efi_init(). Additionally, it expects * efi_memmap_init_early() to have already been called. * * The reason there are two EFI memmap initialisation * (efi_memmap_init_early() and this late version) is because the * early EFI memmap should be explicitly unmapped once EFI * initialisation is complete as the fixmap space used to map the EFI * memmap (via early_memremap()) is a scarce resource. * * This late mapping is intended to persist for the duration of * runtime so that things like efi_mem_desc_lookup() and * efi_mem_attributes() always work. * * Returns: zero on success, a negative error code on failure. */int __init efi_memmap_init_late(phys_addr_t addr, unsigned long size){	struct efi_memory_map_data data = {		.phys_map = addr,		.size = size,		.flags = EFI_MEMMAP_LATE,	}; 	/* Did we forget to unmap the early EFI memmap? */	WARN_ON(efi.memmap.map); 	/* Were we already called? */	WARN_ON(efi.memmap.flags & EFI_MEMMAP_LATE); 	/*	 * It makes no sense to allow callers to register different	 * values for the following fields. Copy them out of the	 * existing early EFI memmap.	 */	data.desc_version = efi.memmap.desc_version;	data.desc_size = efi.memmap.desc_size; 	return __efi_memmap_init(&data);}