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