efi: Update efi_mem_type() to return an error rather than 0

The efi_mem_type() function currently returns a 0, which maps to
EFI_RESERVED_TYPE, if the function is unable to find a memmap entry for
the supplied physical address. Returning EFI_RESERVED_TYPE implies that
a memmap entry exists, when it doesn't.  Instead of returning 0, change
the function to return a negative error value when no memmap entry is
found.

Signed-off-by: Tom Lendacky <[email protected]>
Reviewed-by: Thomas Gleixner <[email protected]>
Reviewed-by: Matt Fleming <[email protected]>
Reviewed-by: Borislav Petkov <[email protected]>
Cc: Alexander Potapenko <[email protected]>
Cc: Andrey Ryabinin <[email protected]>
Cc: Andy Lutomirski <[email protected]>
Cc: Arnd Bergmann <[email protected]>
Cc: Borislav Petkov <[email protected]>
Cc: Brijesh Singh <[email protected]>
Cc: Dave Young <[email protected]>
Cc: Dmitry Vyukov <[email protected]>
Cc: Jonathan Corbet <[email protected]>
Cc: Konrad Rzeszutek Wilk <[email protected]>
Cc: Larry Woodman <[email protected]>
Cc: Linus Torvalds <[email protected]>
Cc: Michael S. Tsirkin <[email protected]>
Cc: Paolo Bonzini <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Radim Krčmář <[email protected]>
Cc: Rik van Riel <[email protected]>
Cc: Toshimitsu Kani <[email protected]>
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Link: http://lkml.kernel.org/r/7fbf40a9dc414d5da849e1ddcd7f7c1285e4e181.1500319216.git.thomas.lendacky@amd.com
Signed-off-by: Ingo Molnar <[email protected]>

1 files changed, 3 insertions, 3 deletions

diff --git a/arch/x86/platform/efi/efi.c b/arch/x86/platform/efi/efi.c
index f084d8718ac4..6217b23e85f6 100644
--- a/arch/x86/platform/efi/efi.c
+++ b/arch/x86/platform/efi/efi.c
@@ -1035,12 +1035,12 @@ void __init efi_enter_virtual_mode(void)
 /*
  * Convenience functions to obtain memory types and attributes
  */
-u32 efi_mem_type(unsigned long phys_addr)
+int efi_mem_type(unsigned long phys_addr)
 {
 	efi_memory_desc_t *md;
 
 	if (!efi_enabled(EFI_MEMMAP))
-		return 0;
+		return -ENOTSUPP;
 
 	for_each_efi_memory_desc(md) {
 		if ((md->phys_addr <= phys_addr) &&
@@ -1048,7 +1048,7 @@ u32 efi_mem_type(unsigned long phys_addr)
 				  (md->num_pages << EFI_PAGE_SHIFT))))
 			return md->type;
 	}
-	return 0;
+	return -EINVAL;
 }
 
 static int __init arch_parse_efi_cmdline(char *str)