[PATCHv4 2/8] efi/x86: Get full memory map in allocate_e820()

Kirill A. Shutemov
2022-04-05T23:48:41Z

Currently allocate_e820() only interested in the size of map and size of
memory descriptor to determine how many e820 entries the kernel needs.

UEFI Specification version 2.9 introduces a new memory type --
unaccepted memory. To track unaccepted memory kernel needs to allocate
a bitmap. The size of the bitmap is dependent on the maximum physical
address present in the system. A full memory map is required to find
the maximum address.

Modify allocate_e820() to get a full memory map.

This is preparation for the next patch that implements handling of
unaccepted memory in EFI stub.

Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
---
drivers/firmware/efi/libstub/x86-stub.c | 28 ++++++++++++-------------
1 file changed, 13 insertions(+), 15 deletions(-)

diff --git a/drivers/firmware/efi/libstub/x86-stub.c b/drivers/firmware/efi/libstub/x86-stub.c
index 01ddd4502e28..d18cac8ab436 100644
--- a/drivers/firmware/efi/libstub/x86-stub.c
+++ b/drivers/firmware/efi/libstub/x86-stub.c
@@ -569,30 +569,28 @@ static efi_status_t alloc_e820ext(u32 nr_desc, struct setup_data **e820ext,
}

static efi_status_t allocate_e820(struct boot_params *params,
+ struct efi_boot_memmap *map,
struct setup_data **e820ext,
u32 *e820ext_size)
{
- unsigned long map_size, desc_size, map_key;
efi_status_t status;
- __u32 nr_desc, desc_version;
+ __u32 nr_desc;

- /* Only need the size of the mem map and size of each mem descriptor */
- map_size = 0;
- status = efi_bs_call(get_memory_map, &map_size, NULL, &map_key,
- &desc_size, &desc_version);
- if (status != EFI_BUFFER_TOO_SMALL)
- return (status != EFI_SUCCESS) ? status : EFI_UNSUPPORTED;
-
- nr_desc = map_size / desc_size + EFI_MMAP_NR_SLACK_SLOTS;
+ status = efi_get_memory_map(map);
+ if (status != EFI_SUCCESS)
+ return status;

- if (nr_desc > ARRAY_SIZE(params->e820_table)) {
- u32 nr_e820ext = nr_desc - ARRAY_SIZE(params->e820_table);
+ nr_desc = *map->map_size / *map->desc_size;
+ if (nr_desc > ARRAY_SIZE(params->e820_table) - EFI_MMAP_NR_SLACK_SLOTS) {
+ u32 nr_e820ext = nr_desc - ARRAY_SIZE(params->e820_table) +
+ EFI_MMAP_NR_SLACK_SLOTS;

status = alloc_e820ext(nr_e820ext, e820ext, e820ext_size);
if (status != EFI_SUCCESS)
- return status;
+ goto out;
}
-
+out:
+ efi_bs_call(free_pool, *map->map);
return EFI_SUCCESS;
}

@@ -642,7 +640,7 @@ static efi_status_t exit_boot(struct boot_params *boot_params, void *handle)
priv.boot_params = boot_params;
priv.efi = &boot_params->efi_info;

- status = allocate_e820(boot_params, &e820ext, &e820ext_size);
+ status = allocate_e820(boot_params, &map, &e820ext, &e820ext_size);
if (status != EFI_SUCCESS)
return status;

--
2.35.1