efi: Make code to find mirrored memory ranges generic

Commit b05b9f5f ("x86, mirror: x86 enabling - find mirrored memory
ranges") introduce the efi_find_mirror() function on x86. In order to reuse
the API we make it public.

Arm64 can support mirrored memory too, so function efi_find_mirror() is added to
efi_init() to this support for arm64.

Since efi_init() is shared by ARM, arm64 and riscv, this patch will bring
mirror memory support for these architectures, but this support is only tested
in arm64.
Signed-off-by: Ma Wupeng <mawupeng1@huawei.com>
Link: https://lore.kernel.org/r/20220614092156.1972846-2-mawupeng1@huawei.com
[ardb: fix subject to better reflect the payload]
Acked-by: Mike Rapoport <rppt@linux.ibm.com>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>

arch/x86/include/asm/efi.h

@@ -383,7 +383,6 @@ static inline bool efi_is_64bit(void)
 extern bool efi_reboot_required(void);
 extern bool efi_is_table_address(unsigned long phys_addr);
 
-extern void efi_find_mirror(void);
 extern void efi_reserve_boot_services(void);
 #else
 static inline void parse_efi_setup(u64 phys_addr, u32 data_len) {}
@@ -395,9 +394,6 @@ static inline  bool efi_is_table_address(unsigned long phys_addr)
 {
 	return false;
 }
-static inline void efi_find_mirror(void)
-{
-}
 static inline void efi_reserve_boot_services(void)
 {
 }

arch/x86/platform/efi/efi.c

@@ -108,29 +108,6 @@ static int __init setup_add_efi_memmap(char *arg)
 }
 early_param("add_efi_memmap", setup_add_efi_memmap);
 
-void __init efi_find_mirror(void)
-{
-	efi_memory_desc_t *md;
-	u64 mirror_size = 0, total_size = 0;
-
-	if (!efi_enabled(EFI_MEMMAP))
-		return;
-
-	for_each_efi_memory_desc(md) {
-		unsigned long long start = md->phys_addr;
-		unsigned long long size = md->num_pages << EFI_PAGE_SHIFT;
-
-		total_size += size;
-		if (md->attribute & EFI_MEMORY_MORE_RELIABLE) {
-			memblock_mark_mirror(start, size);
-			mirror_size += size;
-		}
-	}
-	if (mirror_size)
-		pr_info("Memory: %lldM/%lldM mirrored memory\n",
-			mirror_size>>20, total_size>>20);
-}
-
 /*
  * Tell the kernel about the EFI memory map.  This might include
  * more than the max 128 entries that can fit in the passed in e820

drivers/firmware/efi/efi-init.c

@@ -240,6 +240,7 @@ void __init efi_init(void)
 	 * And now, memblock is fully populated, it is time to do capping.
 	 */
 	early_init_dt_check_for_usable_mem_range();
+	efi_find_mirror();
 	efi_esrt_init();
 	efi_mokvar_table_init();
 

drivers/firmware/efi/efi.c

@@ -446,6 +446,29 @@ static int __init efisubsys_init(void)
 
 subsys_initcall(efisubsys_init);
 
+void __init efi_find_mirror(void)
+{
+	efi_memory_desc_t *md;
+	u64 mirror_size = 0, total_size = 0;
+
+	if (!efi_enabled(EFI_MEMMAP))
+		return;
+
+	for_each_efi_memory_desc(md) {
+		unsigned long long start = md->phys_addr;
+		unsigned long long size = md->num_pages << EFI_PAGE_SHIFT;
+
+		total_size += size;
+		if (md->attribute & EFI_MEMORY_MORE_RELIABLE) {
+			memblock_mark_mirror(start, size);
+			mirror_size += size;
+		}
+	}
+	if (mirror_size)
+		pr_info("Memory: %lldM/%lldM mirrored memory\n",
+			mirror_size>>20, total_size>>20);
+}
+
 /*
  * Find the efi memory descriptor for a given physical address.  Given a
  * physical address, determine if it exists within an EFI Memory Map entry,

include/linux/efi.h

@@ -872,6 +872,7 @@ static inline bool efi_rt_services_supported(unsigned int mask)
 {
 	return (efi.runtime_supported_mask & mask) == mask;
 }
+extern void efi_find_mirror(void);
 #else
 static inline bool efi_enabled(int feature)
 {
@@ -889,6 +890,8 @@ static inline bool efi_rt_services_supported(unsigned int mask)
 {
 	return false;
 }
+
+static inline void efi_find_mirror(void) {}
 #endif
 
 extern int efi_status_to_err(efi_status_t status);