tmp_suning_uos_patched/drivers/firmware/efi/memmap.c
Ard Biesheuvel 33412b8673 efi/arm: Revert deferred unmap of early memmap mapping
Commit:

  3ea86495ae ("efi/arm: preserve early mapping of UEFI memory map longer for BGRT")

deferred the unmap of the early mapping of the UEFI memory map to
accommodate the ACPI BGRT code, which looks up the memory type that
backs the BGRT table to validate it against the requirements of the UEFI spec.

Unfortunately, this causes problems on ARM, which does not permit
early mappings to persist after paging_init() is called, resulting
in a WARN() splat. Since we don't support the BGRT table on ARM anway,
let's revert ARM to the old behaviour, which is to take down the
early mapping at the end of efi_init().

Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-efi@vger.kernel.org
Fixes: 3ea86495ae ("efi/arm: preserve early mapping of UEFI memory ...")
Link: http://lkml.kernel.org/r/20181114175544.12860-3-ard.biesheuvel@linaro.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-11-15 10:04:46 +01:00

346 lines
8.9 KiB
C

// 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 <asm/early_ioremap.h>
#include <linux/memblock.h>
#include <linux/slab.h>
static phys_addr_t __init __efi_memmap_alloc_early(unsigned long size)
{
return memblock_phys_alloc(size, SMP_CACHE_BYTES);
}
static phys_addr_t __init __efi_memmap_alloc_late(unsigned long size)
{
unsigned int order = get_order(size);
struct page *p = alloc_pages(GFP_KERNEL, order);
if (!p)
return 0;
return PFN_PHYS(page_to_pfn(p));
}
/**
* efi_memmap_alloc - Allocate memory for the EFI memory map
* @num_entries: Number of entries in the allocated map.
*
* Depending on whether mm_init() has already been invoked or not,
* either memblock or "normal" page allocation is used.
*
* Returns the physical address of the allocated memory map on
* success, zero on failure.
*/
phys_addr_t __init efi_memmap_alloc(unsigned int num_entries)
{
unsigned long size = num_entries * efi.memmap.desc_size;
if (slab_is_available())
return __efi_memmap_alloc_late(size);
return __efi_memmap_alloc_early(size);
}
/**
* __efi_memmap_init - Common code for mapping the EFI memory map
* @data: EFI memory map data
* @late: Use early or late mapping function?
*
* 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 @late should be %false 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.
*/
static int __init
__efi_memmap_init(struct efi_memory_map_data *data, bool late)
{
struct efi_memory_map map;
phys_addr_t phys_map;
if (efi_enabled(EFI_PARAVIRT))
return 0;
phys_map = data->phys_map;
if (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!\n");
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.late = late;
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.
*/
int __init efi_memmap_init_early(struct efi_memory_map_data *data)
{
/* Cannot go backwards */
WARN_ON(efi.memmap.late);
return __efi_memmap_init(data, false);
}
void __init efi_memmap_unmap(void)
{
if (!efi_enabled(EFI_MEMMAP))
return;
if (!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()
* @phys_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,
};
/* Did we forget to unmap the early EFI memmap? */
WARN_ON(efi.memmap.map);
/* Were we already called? */
WARN_ON(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, true);
}
/**
* efi_memmap_install - Install a new EFI memory map in efi.memmap
* @addr: Physical address of the memory map
* @nr_map: Number of entries in the memory map
*
* Unlike efi_memmap_init_*(), this function does not allow the caller
* to switch from early to late mappings. It simply uses the existing
* mapping function and installs the new memmap.
*
* Returns zero on success, a negative error code on failure.
*/
int __init efi_memmap_install(phys_addr_t addr, unsigned int nr_map)
{
struct efi_memory_map_data data;
efi_memmap_unmap();
data.phys_map = addr;
data.size = efi.memmap.desc_size * nr_map;
data.desc_version = efi.memmap.desc_version;
data.desc_size = efi.memmap.desc_size;
return __efi_memmap_init(&data, efi.memmap.late);
}
/**
* efi_memmap_split_count - Count number of additional EFI memmap entries
* @md: EFI memory descriptor to split
* @range: Address range (start, end) to split around
*
* Returns the number of additional EFI memmap entries required to
* accomodate @range.
*/
int __init efi_memmap_split_count(efi_memory_desc_t *md, struct range *range)
{
u64 m_start, m_end;
u64 start, end;
int count = 0;
start = md->phys_addr;
end = start + (md->num_pages << EFI_PAGE_SHIFT) - 1;
/* modifying range */
m_start = range->start;
m_end = range->end;
if (m_start <= start) {
/* split into 2 parts */
if (start < m_end && m_end < end)
count++;
}
if (start < m_start && m_start < end) {
/* split into 3 parts */
if (m_end < end)
count += 2;
/* split into 2 parts */
if (end <= m_end)
count++;
}
return count;
}
/**
* efi_memmap_insert - Insert a memory region in an EFI memmap
* @old_memmap: The existing EFI memory map structure
* @buf: Address of buffer to store new map
* @mem: Memory map entry to insert
*
* It is suggested that you call efi_memmap_split_count() first
* to see how large @buf needs to be.
*/
void __init efi_memmap_insert(struct efi_memory_map *old_memmap, void *buf,
struct efi_mem_range *mem)
{
u64 m_start, m_end, m_attr;
efi_memory_desc_t *md;
u64 start, end;
void *old, *new;
/* modifying range */
m_start = mem->range.start;
m_end = mem->range.end;
m_attr = mem->attribute;
/*
* The EFI memory map deals with regions in EFI_PAGE_SIZE
* units. Ensure that the region described by 'mem' is aligned
* correctly.
*/
if (!IS_ALIGNED(m_start, EFI_PAGE_SIZE) ||
!IS_ALIGNED(m_end + 1, EFI_PAGE_SIZE)) {
WARN_ON(1);
return;
}
for (old = old_memmap->map, new = buf;
old < old_memmap->map_end;
old += old_memmap->desc_size, new += old_memmap->desc_size) {
/* copy original EFI memory descriptor */
memcpy(new, old, old_memmap->desc_size);
md = new;
start = md->phys_addr;
end = md->phys_addr + (md->num_pages << EFI_PAGE_SHIFT) - 1;
if (m_start <= start && end <= m_end)
md->attribute |= m_attr;
if (m_start <= start &&
(start < m_end && m_end < end)) {
/* first part */
md->attribute |= m_attr;
md->num_pages = (m_end - md->phys_addr + 1) >>
EFI_PAGE_SHIFT;
/* latter part */
new += old_memmap->desc_size;
memcpy(new, old, old_memmap->desc_size);
md = new;
md->phys_addr = m_end + 1;
md->num_pages = (end - md->phys_addr + 1) >>
EFI_PAGE_SHIFT;
}
if ((start < m_start && m_start < end) && m_end < end) {
/* first part */
md->num_pages = (m_start - md->phys_addr) >>
EFI_PAGE_SHIFT;
/* middle part */
new += old_memmap->desc_size;
memcpy(new, old, old_memmap->desc_size);
md = new;
md->attribute |= m_attr;
md->phys_addr = m_start;
md->num_pages = (m_end - m_start + 1) >>
EFI_PAGE_SHIFT;
/* last part */
new += old_memmap->desc_size;
memcpy(new, old, old_memmap->desc_size);
md = new;
md->phys_addr = m_end + 1;
md->num_pages = (end - m_end) >>
EFI_PAGE_SHIFT;
}
if ((start < m_start && m_start < end) &&
(end <= m_end)) {
/* first part */
md->num_pages = (m_start - md->phys_addr) >>
EFI_PAGE_SHIFT;
/* latter part */
new += old_memmap->desc_size;
memcpy(new, old, old_memmap->desc_size);
md = new;
md->phys_addr = m_start;
md->num_pages = (end - md->phys_addr + 1) >>
EFI_PAGE_SHIFT;
md->attribute |= m_attr;
}
}
}