Extend the kernel parameter add_efi_memmap to have additional
optional arguement "correct." EFI memmaps that are "correct"
aren't accessed by platform firmware after a call to Exit Boot
Services.
Signed-off-by: Jerry Hoemann <jerry.hoemann@xxxxxx>
---
Documentation/kernel-parameters.txt | 8 ++++++++
arch/x86/platform/efi/efi.c | 13 +++++++++++--
2 files changed, 19 insertions(+), 2 deletions(-)
diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index fcbb736..ae1bde6 100644
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -346,6 +346,14 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
add_efi_memmap [EFI; X86] Include EFI memory map in
kernel's map of available physical RAM.
+ add_efi_memmap= [EFI; X86] Include EFI memory map in
+ kernel's map of available physical RAM.
+ Additional Modifies:
+
+ correct: Platform firmware correctly doesn't reuse
+ boot service code or data segments after Exit Boot
+ Services.
+
agp= [AGP]
{ off | try_unsupported }
off: disable AGP support
diff --git a/arch/x86/platform/efi/efi.c b/arch/x86/platform/efi/efi.c
index c7e22ab..0cb1cce 100644
--- a/arch/x86/platform/efi/efi.c
+++ b/arch/x86/platform/efi/efi.c
@@ -103,6 +103,10 @@ EXPORT_SYMBOL(add_efi_memmap);
static int __init setup_add_efi_memmap(char *arg)
{
add_efi_memmap = 1;
+ if (arg && strstr(arg, "correct")) {
+ pr_info("%s: setting EFI_MEMMAP_CORRECT\n", __func__);
+ set_bit(EFI_MEMMAP_CORRECT, &x86_efi_facility);
+ }
return 0;
}
early_param("add_efi_memmap", setup_add_efi_memmap);
@@ -422,6 +426,8 @@ static void __init print_efi_memmap(void)
}
#endif /* EFI_DEBUG */
+static int efi_boot_services_reservations;
+
void __init efi_reserve_boot_services(void)
{
void *p;
@@ -449,8 +455,10 @@ void __init efi_reserve_boot_services(void)
memblock_dbg("Could not reserve boot range "
"[0x%010llx-0x%010llx]\n",
start, start+size-1);
- } else
+ } else {
memblock_reserve(start, size);
+ efi_boot_services_reservations++;
+ }
}
}
@@ -467,7 +475,7 @@ void __init efi_free_boot_services(void)
{
void *p;
- if (!efi_is_native())
+ if (!efi_is_native() || !efi_boot_services_reservations)
return;
for (p = memmap.map; p < memmap.map_end; p += memmap.desc_size) {
@@ -484,6 +492,7 @@ void __init efi_free_boot_services(void)
continue;
free_bootmem_late(start, size);
+ efi_boot_services_reservations--;
}
efi_unmap_memmap();
--
1.7.11.3
--
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