linux/drivers/firmware/efi/arm-init.c
Matt Fleming 9479c7cebf efi: Refactor efi_memmap_init_early() into arch-neutral code
Every EFI architecture apart from ia64 needs to setup the EFI memory
map at efi.memmap, and the code for doing that is essentially the same
across all implementations. Therefore, it makes sense to factor this
out into the common code under drivers/firmware/efi/.

The only slight variation is the data structure out of which we pull
the initial memory map information, such as physical address, memory
descriptor size and version, etc. We can address this by passing a
generic data structure (struct efi_memory_map_data) as the argument to
efi_memmap_init_early() which contains the minimum info required for
initialising the memory map.

In the process, this patch also fixes a few undesirable implementation
differences:

 - ARM and arm64 were failing to clear the EFI_MEMMAP bit when
   unmapping the early EFI memory map. EFI_MEMMAP indicates whether
   the EFI memory map is mapped (not the regions contained within) and
   can be traversed.  It's more correct to set the bit as soon as we
   memremap() the passed in EFI memmap.

 - Rename efi_unmmap_memmap() to efi_memmap_unmap() to adhere to the
   regular naming scheme.

This patch also uses a read-write mapping for the memory map instead
of the read-only mapping currently used on ARM and arm64. x86 needs
the ability to update the memory map in-place when assigning virtual
addresses to regions (efi_map_region()) and tagging regions when
reserving boot services (efi_reserve_boot_services()).

There's no way for the generic fake_mem code to know which mapping to
use without introducing some arch-specific constant/hook, so just use
read-write since read-only is of dubious value for the EFI memory map.

Tested-by: Dave Young <dyoung@redhat.com> [kexec/kdump]
Tested-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> [arm]
Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Leif Lindholm <leif.lindholm@linaro.org>
Cc: Peter Jones <pjones@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Matt Fleming <matt@codeblueprint.co.uk>
2016-09-09 16:06:38 +01:00

271 lines
6.6 KiB
C

/*
* 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_normal_ram(efi_memory_desc_t *md)
{
if (md->attribute & EFI_MEMORY_WB)
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 RAM regions we want to permanently reserve.
*/
static __init int is_reserve_region(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:
return 0;
default:
break;
}
return is_normal_ram(md);
}
static __init void reserve_regions(void)
{
efi_memory_desc_t *md;
u64 paddr, npages, size;
int resv;
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;
resv = is_reserve_region(md);
if (efi_enabled(EFI_DBG)) {
char buf[64];
pr_info(" 0x%012llx-0x%012llx %s%s\n",
paddr, paddr + (npages << EFI_PAGE_SHIFT) - 1,
efi_md_typeattr_format(buf, sizeof(buf), md),
resv ? "*" : "");
}
memrange_efi_to_native(&paddr, &npages);
size = npages << PAGE_SHIFT;
if (is_normal_ram(md))
early_init_dt_add_memory_arch(paddr, size);
if (resv)
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_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);