[PATCH v5 04/14] efi: add a wrapper function efi_map_region_fixed

[Dave Young <dyoung-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>]

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.

Matt: coding style
      reuse __map_region
Boris: Strenthen comment lines to 80 cols.

Signed-off-by: Dave Young <dyoung-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
Acked-by: Borislav Petkov <bp-l3A5Bk7waGM@public.gmane.org>
---
 arch/x86/include/asm/efi.h     |  1 +
 arch/x86/platform/efi/efi_32.c |  2 ++
 arch/x86/platform/efi/efi_64.c | 10 ++++++++++
 3 files changed, 13 insertions(+)

diff --git a/arch/x86/include/asm/efi.h b/arch/x86/include/asm/efi.h
index 89a05b0..9fbaeb2 100644
--- a/arch/x86/include/asm/efi.h
+++ b/arch/x86/include/asm/efi.h
@@ -128,6 +128,7 @@ extern void efi_call_phys_epilog(void);
 extern void efi_unmap_memmap(void);
 extern void efi_memory_uc(u64 addr, unsigned long size);
 extern void __init efi_map_region(efi_memory_desc_t *md);
+extern void __init efi_map_region_fixed(efi_memory_desc_t *md);
 extern void efi_sync_low_kernel_mappings(void);
 extern void efi_setup_page_tables(void);
 extern void __init old_map_region(efi_memory_desc_t *md);
diff --git a/arch/x86/platform/efi/efi_32.c b/arch/x86/platform/efi/efi_32.c
index e94557c..7b3ec6e 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 c5a6491..ff08cb1 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)
 {
-- 
1.8.3.1