src/console: Add x86 romstage spinlock option and printk spinlock support

This paves the way for AP printk spinlock on AMD platforms

Change-Id: Ice42a0d3177736bf6e1bc601092e413601866f20
Signed-off-by: Timothy Pearson <tpearson@raptorengineeringinc.com>
Reviewed-on: https://review.coreboot.org/11958
Tested-by: Raptor Engineering Automated Test Stand <noreply@raptorengineeringinc.com>
Tested-by: build bot (Jenkins)
Reviewed-by: Martin Roth <martinroth@google.com>

src/Kconfig

@@ -476,6 +476,10 @@ config HAVE_HARD_RESET
 	  This variable specifies whether a given board has a hard_reset
 	  function, no matter if it's provided by board code or chipset code.
 
+config HAVE_ROMSTAGE_CONSOLE_SPINLOCK
+	bool
+	default n
+
 config HAVE_MONOTONIC_TIMER
 	def_bool n
 	help

src/arch/x86/include/arch/smp/spinlock.h

@@ -1,7 +1,7 @@
 #ifndef ARCH_SMP_SPINLOCK_H
 #define ARCH_SMP_SPINLOCK_H
 
-#ifndef __PRE_RAM__
+#if !defined(__PRE_RAM__) || IS_ENABLED(CONFIG_HAVE_ROMSTAGE_CONSOLE_SPINLOCK)
 
 /*
  * Your basic SMP spinlocks, allowing only a single CPU anywhere
@@ -11,9 +11,18 @@ typedef struct {
 	volatile unsigned int lock;
 } spinlock_t;
 
+#ifdef __PRE_RAM__
+spinlock_t *romstage_console_lock(void);
+void initialize_romstage_console_lock(void);
+#endif
 
 #define SPIN_LOCK_UNLOCKED (spinlock_t) { 1 }
+
+#ifndef __PRE_RAM__
 #define DECLARE_SPIN_LOCK(x) static spinlock_t x = SPIN_LOCK_UNLOCKED;
+#else
+#define DECLARE_SPIN_LOCK(x)
+#endif
 
 /*
  * Simple spin lock operations.  There are two variants, one clears IRQ's

src/console/printk.c

@@ -2,6 +2,7 @@
  *  blatantly copied from linux/kernel/printk.c
  *
  *  Copyright (C) 1991, 1992  Linus Torvalds
+ *  Copyright (C) 2015 Timothy Pearson <tpearson@raptorengineeringinc.com>, Raptor Engineering
  *
  */
 
@@ -13,7 +14,9 @@
 #include <stddef.h>
 #include <trace.h>
 
+#if (!defined(__PRE_RAM__) && IS_ENABLED(CONFIG_HAVE_ROMSTAGE_CONSOLE_SPINLOCK)) || !IS_ENABLED(CONFIG_HAVE_ROMSTAGE_CONSOLE_SPINLOCK)
 DECLARE_SPIN_LOCK(console_lock)
+#endif
 
 void do_putchar(unsigned char byte)
 {
@@ -39,7 +42,13 @@ int do_printk(int msg_level, const char *fmt, ...)
 #endif
 
 	DISABLE_TRACE;
+#ifdef __PRE_RAM__
+#if IS_ENABLED(CONFIG_HAVE_ROMSTAGE_CONSOLE_SPINLOCK)
+	spin_lock(romstage_console_lock());
+#endif
+#else
 	spin_lock(&console_lock);
+#endif
 
 	va_start(args, fmt);
 	i = vtxprintf(wrap_putchar, fmt, args, NULL);
@@ -47,7 +56,13 @@ int do_printk(int msg_level, const char *fmt, ...)
 
 	console_tx_flush();
 
+#ifdef __PRE_RAM__
+#if IS_ENABLED(CONFIG_HAVE_ROMSTAGE_CONSOLE_SPINLOCK)
+	spin_unlock(romstage_console_lock());
+#endif
+#else
 	spin_unlock(&console_lock);
+#endif
 	ENABLE_TRACE;
 
 	return i;

src/cpu/amd/car/post_cache_as_ram.c

@@ -76,6 +76,10 @@ static void prepare_ramstage_region(void *resume_backup_memory)
 		memset_((void*)0, 0, CONFIG_RAMTOP - backup_top);
 	}
 
+#if IS_ENABLED(CONFIG_HAVE_ROMSTAGE_CONSOLE_SPINLOCK)
+	initialize_romstage_console_lock();
+#endif
+
 	print_car_debug(" Done\n");
 }