x86: make early printk selectable on 64-bit as well
Enable CONFIG_EMBEDDED to select CONFIG_EARLY_PRINTK on 64-bit as well.
saves ~2K:
text data bss dec hex filename
7290283 3672091 1907848 12870222 c4624e vmlinux.before
7288373 3671795 1907848 12868016 c459b0 vmlinux.after
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
diff --git a/arch/x86/Kconfig.debug b/arch/x86/Kconfig.debug
index 15854b5..88420af 100644
--- a/arch/x86/Kconfig.debug
+++ b/arch/x86/Kconfig.debug
@@ -6,7 +6,7 @@
source "lib/Kconfig.debug"
config EARLY_PRINTK
- bool "Early printk" if EMBEDDED && DEBUG_KERNEL && X86_32
+ bool "Early printk" if EMBEDDED
default y
help
Write kernel log output directly into the VGA buffer or to a serial
diff --git a/arch/x86/kernel/head64.c b/arch/x86/kernel/head64.c
index 85c1e6bf..87e031d 100644
--- a/arch/x86/kernel/head64.c
+++ b/arch/x86/kernel/head64.c
@@ -58,8 +58,13 @@
/* Make NULL pointers segfault */
zap_identity_mappings();
- for (i = 0; i < IDT_ENTRIES; i++)
+ for (i = 0; i < IDT_ENTRIES; i++) {
+#ifdef CONFIG_EARLY_PRINTK
set_intr_gate(i, &early_idt_handlers[i]);
+#else
+ set_intr_gate(i, early_idt_handler);
+#endif
+ }
load_idt((const struct desc_ptr *)&idt_descr);
early_printk("Kernel alive\n");
diff --git a/arch/x86/kernel/head_64.S b/arch/x86/kernel/head_64.S
index 8b4c35c..1d5a7a3 100644
--- a/arch/x86/kernel/head_64.S
+++ b/arch/x86/kernel/head_64.S
@@ -267,6 +267,7 @@
bad_address:
jmp bad_address
+#ifdef CONFIG_EARLY_PRINTK
.macro early_idt_tramp first, last
.ifgt \last-\first
early_idt_tramp \first, \last-1
@@ -281,8 +282,10 @@
early_idt_tramp 64, 127
early_idt_tramp 128, 191
early_idt_tramp 192, 255
+#endif
ENTRY(early_idt_handler)
+#ifdef CONFIG_EARLY_PRINTK
cmpl $2,early_recursion_flag(%rip)
jz 1f
incl early_recursion_flag(%rip)
@@ -311,8 +314,11 @@
movq 8(%rsp),%rsi # get rip again
call __print_symbol
#endif
+#endif /* EARLY_PRINTK */
1: hlt
jmp 1b
+
+#ifdef CONFIG_EARLY_PRINTK
early_recursion_flag:
.long 0
@@ -320,6 +326,7 @@
.asciz "PANIC: early exception %02lx rip %lx:%lx error %lx cr2 %lx\n"
early_idt_ripmsg:
.asciz "RIP %s\n"
+#endif /* CONFIG_EARLY_PRINTK */
.balign PAGE_SIZE
diff --git a/include/asm-x86/kdebug.h b/include/asm-x86/kdebug.h
index a5e5e3b..e9f42d1 100644
--- a/include/asm-x86/kdebug.h
+++ b/include/asm-x86/kdebug.h
@@ -22,7 +22,6 @@
DIE_PAGE_FAULT,
};
-extern void early_printk(const char *fmt, ...) __attribute__((format(printf,1,2)));
extern void printk_address(unsigned long address);
extern void die(const char *,struct pt_regs *,long);
extern int __must_check __die(const char *, struct pt_regs *, long);
diff --git a/include/linux/kernel.h b/include/linux/kernel.h
index a7283c9..ff356b2 100644
--- a/include/linux/kernel.h
+++ b/include/linux/kernel.h
@@ -194,6 +194,9 @@
static inline int log_buf_copy(char *dest, int idx, int len) { return 0; }
#endif
+extern void __attribute__((format(printf, 1, 2)))
+ early_printk(const char *fmt, ...);
+
unsigned long int_sqrt(unsigned long);
extern int printk_ratelimit(void);
diff --git a/kernel/printk.c b/kernel/printk.c
index 3b7c968..58bbec6 100644
--- a/kernel/printk.c
+++ b/kernel/printk.c
@@ -36,6 +36,13 @@
#include <asm/uaccess.h>
+/*
+ * Architectures can override it:
+ */
+void __attribute__((weak)) early_printk(const char *fmt, ...)
+{
+}
+
#define __LOG_BUF_LEN (1 << CONFIG_LOG_BUF_SHIFT)
/* printk's without a loglevel use this.. */