x86: Implement reset_cpu() correctly for modern CPUs

The existing code is pretty ancient and is unreliable on modern hardware.
Generally it will hang.

We can use port 0xcf9 to initiate reset on more modern hardware (say in the
last 10 years). Update the reset_cpu() function to do this, and add a new
'full reset' function to perform a full power cycle.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>

1 files changed, 9 insertions, 13 deletions

diff --git a/arch/x86/cpu/cpu.c b/arch/x86/cpu/cpu.c
index c9614f122f..02e66d80db 100644
--- a/arch/x86/cpu/cpu.c
+++ b/arch/x86/cpu/cpu.c
@@ -380,21 +380,17 @@ void  flush_cache(unsigned long dummy1, unsigned long dummy2)
 	asm("wbinvd\n");
 }
 
-void __attribute__ ((regparm(0))) generate_gpf(void);
-
-/* segment 0x70 is an arbitrary segment which does not exist */
-asm(".globl generate_gpf\n"
-	".hidden generate_gpf\n"
-	".type generate_gpf, @function\n"
-	"generate_gpf:\n"
-	"ljmp   $0x70, $0x47114711\n");
-
 __weak void reset_cpu(ulong addr)
 {
-	printf("Resetting using x86 Triple Fault\n");
-	set_vector(13, generate_gpf);	/* general protection fault handler */
-	set_vector(8, generate_gpf);	/* double fault handler */
-	generate_gpf();			/* start the show */
+	/* Do a hard reset through the chipset's reset control register */
+	outb(SYS_RST | RST_CPU, PORT_RESET);
+	for (;;)
+		cpu_hlt();
+}
+
+void x86_full_reset(void)
+{
+	outb(FULL_RST | SYS_RST | RST_CPU, PORT_RESET);
 }
 
 int dcache_status(void)