x86/efi: Add a wrapper function efi_map_region_fixed()

Kexec kernel will use saved runtime virtual mapping, so add a new
function efi_map_region_fixed() for directly mapping a md to md->virt.

The md is passed in from 1st kernel, the virtual addr is saved in
md->virt_addr.

Signed-off-by: Dave Young <dyoung@redhat.com>
Acked-by: Borislav Petkov <bp@suse.de>
Tested-by: Toshi Kani <toshi.kani@hp.com>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>

2 files changed, 12 insertions, 0 deletions

diff --git a/arch/x86/platform/efi/efi_32.c b/arch/x86/platform/efi/efi_32.c
index e94557cf5487..7b3ec6ed99af 100644
--- a/arch/x86/platform/efi/efi_32.c
+++ b/arch/x86/platform/efi/efi_32.c
@@ -47,6 +47,8 @@ void __init efi_map_region(efi_memory_desc_t *md)
         old_map_region(md);
 }
 
+void __init efi_map_region_fixed(efi_memory_desc_t *md) {}
+
 void efi_call_phys_prelog(void)
 {
         struct desc_ptr gdt_descr;
diff --git a/arch/x86/platform/efi/efi_64.c b/arch/x86/platform/efi/efi_64.c
index c5a6491d95da..ff08cb19630b 100644
--- a/arch/x86/platform/efi/efi_64.c
+++ b/arch/x86/platform/efi/efi_64.c
@@ -199,6 +199,16 @@ void __init efi_map_region(efi_memory_desc_t *md)
         md->virt_addr = efi_va;
 }
 
+/*
+ * kexec kernel will use efi_map_region_fixed to map efi runtime memory ranges.
+ * md->virt_addr is the original virtual address which had been mapped in kexec
+ * 1st kernel.
+ */
+void __init efi_map_region_fixed(efi_memory_desc_t *md)
+{
+        __map_region(md, md->virt_addr);
+}
+
 void __iomem *__init efi_ioremap(unsigned long phys_addr, unsigned long size,
                                  u32 type, u64 attribute)
 {