[PATCH] LoongArch: Use correct API to map cmdline in relocate_kernel()

From: Huacai Chen
Date: Tue Jul 02 2024 - 11:14:34 EST


fw_arg1 is in memory space rather than I/O space, so we should use
early_memremap_ro() instead of early_ioremap() to map the cmdline.
Moreover, we should unmap it after using.

Suggested-by: Jiaxun Yang <jiaxun.yang@xxxxxxxxxxx>
Signed-off-by: Huacai Chen <chenhuacai@xxxxxxxxxxx>
---
arch/loongarch/kernel/relocate.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/arch/loongarch/kernel/relocate.c b/arch/loongarch/kernel/relocate.c
index 1acfa704c8d0..0eddd4a66b87 100644
--- a/arch/loongarch/kernel/relocate.c
+++ b/arch/loongarch/kernel/relocate.c
@@ -13,6 +13,7 @@
#include <asm/bootinfo.h>
#include <asm/early_ioremap.h>
#include <asm/inst.h>
+#include <asm/io.h>
#include <asm/sections.h>
#include <asm/setup.h>

@@ -170,7 +171,7 @@ unsigned long __init relocate_kernel(void)
unsigned long kernel_length;
unsigned long random_offset = 0;
void *location_new = _text; /* Default to original kernel start */
- char *cmdline = early_ioremap(fw_arg1, COMMAND_LINE_SIZE); /* Boot command line is passed in fw_arg1 */
+ char *cmdline = early_memremap_ro(fw_arg1, COMMAND_LINE_SIZE); /* Boot command line is passed in fw_arg1 */

strscpy(boot_command_line, cmdline, COMMAND_LINE_SIZE);

@@ -182,6 +183,7 @@ unsigned long __init relocate_kernel(void)
random_offset = (unsigned long)location_new - (unsigned long)(_text);
#endif
reloc_offset = (unsigned long)_text - VMLINUX_LOAD_ADDRESS;
+ early_memunmap(cmdline, COMMAND_LINE_SIZE);

if (random_offset) {
kernel_length = (long)(_end) - (long)(_text);
--
2.43.0