From: Ard Biesheuvel <ardb@kernel.org>
Date: Tue, 5 May 2020 10:27:18 +0200
Subject: efi/libstub: Make efi_printk() input argument const char*
Patch-mainline: v5.8-rc1
Git-commit: 0b8d9fc9953fde4ea3eb3191d986ca2d01eb783c
References: jsc#SLE-16407

To help the compiler figure out that efi_printk() will not modify
the string it is given, make the input argument type const char*.

While at it, simplify the implementation as well.

Suggested-by: Joe Perches <joe@perches.com>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Acked-by: Lee, Chun-Yi <jlee@suse.com>
---
 drivers/firmware/efi/libstub/efi-stub-helper.c |   19 +++++++------------
 drivers/firmware/efi/libstub/efistub.h         |    2 +-
 2 files changed, 8 insertions(+), 13 deletions(-)

--- a/drivers/firmware/efi/libstub/efi-stub-helper.c
+++ b/drivers/firmware/efi/libstub/efi-stub-helper.c
@@ -26,20 +26,15 @@ bool __pure __efi_soft_reserve_enabled(v
 	return !efi_nosoftreserve;
 }
 
-void efi_printk(char *str)
+void efi_printk(const char *str)
 {
-	char *s8;
+	while (*str) {
+		efi_char16_t ch[] = { *str++, L'\0' };
 
-	for (s8 = str; *s8; s8++) {
-		efi_char16_t ch[2] = { 0 };
-
-		ch[0] = *s8;
-		if (*s8 == '\n') {
-			efi_char16_t nl[2] = { '\r', 0 };
-			efi_char16_printk(nl);
-		}
-
-		efi_char16_printk(ch);
+		if (ch[0] == L'\n')
+			efi_char16_printk(L"\r\n");
+		else
+			efi_char16_printk(ch);
 	}
 }
 
--- a/drivers/firmware/efi/libstub/efistub.h
+++ b/drivers/firmware/efi/libstub/efistub.h
@@ -638,7 +638,7 @@ efi_status_t check_platform_features(voi
 
 void *get_efi_config_table(efi_guid_t guid);
 
-void efi_printk(char *str);
+void efi_printk(const char *str);
 
 void efi_free(unsigned long size, unsigned long addr);