blob: f03ddecd232b542ce4c7163506b69da0d29ad2c7 [file] [log] [blame]
/*
* 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>
/**
* __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.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;
}
}
}