Merge tag 'for-v4.6-rc/omap-fixes-a' of git://git.kernel.org/pub/scm/linux/kernel/git/pjw/omap-pending into omap-for-v4.6/fixes

ARM: OMAP2+: first hwmod fix for v4.6-rc

Fix a longstanding bug in the hwmod code that could cause
hardware SYSCONFIG register values to not match the kernel's
idea of what they should be, and that could result in lower
performance during IP block idle entry.

Basic build, boot, and PM test logs are available here:

http://www.pwsan.com/omap/testlogs/omap-hwmod-fixes-a-for-v4.6-rc/20160326231727/

1 files changed, 46 insertions, 15 deletions

diff --git a/kernel/panic.c b/kernel/panic.c
index d96469de72dc..535c96510a44 100644
--- a/kernel/panic.c
+++ b/kernel/panic.c
@@ -24,6 +24,7 @@
 #include <linux/init.h>
 #include <linux/nmi.h>
 #include <linux/console.h>
+#include <linux/bug.h>
 
 #define PANIC_TIMER_STEP 100
 #define PANIC_BLINK_SPD 18
@@ -72,6 +73,26 @@ void __weak nmi_panic_self_stop(struct pt_regs *regs)
 
 atomic_t panic_cpu = ATOMIC_INIT(PANIC_CPU_INVALID);
 
+/*
+ * A variant of panic() called from NMI context. We return if we've already
+ * panicked on this CPU. If another CPU already panicked, loop in
+ * nmi_panic_self_stop() which can provide architecture dependent code such
+ * as saving register state for crash dump.
+ */
+void nmi_panic(struct pt_regs *regs, const char *msg)
+{
+	int old_cpu, cpu;
+
+	cpu = raw_smp_processor_id();
+	old_cpu = atomic_cmpxchg(&panic_cpu, PANIC_CPU_INVALID, cpu);
+
+	if (old_cpu == PANIC_CPU_INVALID)
+		panic("%s", msg);
+	else if (old_cpu != cpu)
+		nmi_panic_self_stop(regs);
+}
+EXPORT_SYMBOL(nmi_panic);
+
 /**
  *	panic - halt the system
  *	@fmt: The text string to print
@@ -449,20 +470,25 @@ void oops_exit(void)
 	kmsg_dump(KMSG_DUMP_OOPS);
 }
 
-#ifdef WANT_WARN_ON_SLOWPATH
-struct slowpath_args {
+struct warn_args {
 	const char *fmt;
 	va_list args;
 };
 
-static void warn_slowpath_common(const char *file, int line, void *caller,
-				 unsigned taint, struct slowpath_args *args)
+void __warn(const char *file, int line, void *caller, unsigned taint,
+	    struct pt_regs *regs, struct warn_args *args)
 {
 	disable_trace_on_warning();
 
 	pr_warn("------------[ cut here ]------------\n");
-	pr_warn("WARNING: CPU: %d PID: %d at %s:%d %pS()\n",
-		raw_smp_processor_id(), current->pid, file, line, caller);
+
+	if (file)
+		pr_warn("WARNING: CPU: %d PID: %d at %s:%d %pS\n",
+			raw_smp_processor_id(), current->pid, file, line,
+			caller);
+	else
+		pr_warn("WARNING: CPU: %d PID: %d at %pS\n",
+			raw_smp_processor_id(), current->pid, caller);
 
 	if (args)
 		vprintk(args->fmt, args->args);
@@ -479,20 +505,27 @@ static void warn_slowpath_common(const char *file, int line, void *caller,
 	}
 
 	print_modules();
-	dump_stack();
+
+	if (regs)
+		show_regs(regs);
+	else
+		dump_stack();
+
 	print_oops_end_marker();
+
 	/* Just a warning, don't kill lockdep. */
 	add_taint(taint, LOCKDEP_STILL_OK);
 }
 
+#ifdef WANT_WARN_ON_SLOWPATH
 void warn_slowpath_fmt(const char *file, int line, const char *fmt, ...)
 {
-	struct slowpath_args args;
+	struct warn_args args;
 
 	args.fmt = fmt;
 	va_start(args.args, fmt);
-	warn_slowpath_common(file, line, __builtin_return_address(0),
-			     TAINT_WARN, &args);
+	__warn(file, line, __builtin_return_address(0), TAINT_WARN, NULL,
+	       &args);
 	va_end(args.args);
 }
 EXPORT_SYMBOL(warn_slowpath_fmt);
@@ -500,20 +533,18 @@ EXPORT_SYMBOL(warn_slowpath_fmt);
 void warn_slowpath_fmt_taint(const char *file, int line,
 			     unsigned taint, const char *fmt, ...)
 {
-	struct slowpath_args args;
+	struct warn_args args;
 
 	args.fmt = fmt;
 	va_start(args.args, fmt);
-	warn_slowpath_common(file, line, __builtin_return_address(0),
-			     taint, &args);
+	__warn(file, line, __builtin_return_address(0), taint, NULL, &args);
 	va_end(args.args);
 }
 EXPORT_SYMBOL(warn_slowpath_fmt_taint);
 
 void warn_slowpath_null(const char *file, int line)
 {
-	warn_slowpath_common(file, line, __builtin_return_address(0),
-			     TAINT_WARN, NULL);
+	__warn(file, line, __builtin_return_address(0), TAINT_WARN, NULL, NULL);
 }
 EXPORT_SYMBOL(warn_slowpath_null);
 #endif