From c58655edc007032a9ab4b60f050bf1ecb1a7191f Mon Sep 17 00:00:00 2001
From: Ralf Baechle <ralf@linux-mips.org>
Date: Tue, 17 Jul 2007 18:49:48 +0100
Subject: [PATCH] --- yaml --- r: 62199 b: refs/heads/master c:
 5a81299928f3d9abfaced60bedd85214cf9921a4 h: refs/heads/master i:   62197:
 64a09559237c657364fb2972495e05a319e23565   62195:
 61b59ac762120a5c3c786055abe48d35eb00f9da   62191:
 fab9718a2090723a15d36d87f73f3f136fbe829a v: v3

---
 [refs]                             |  2 +-
 trunk/arch/mips/kernel/cpu-probe.c | 26 +++++++++++++++++++++++++-
 2 files changed, 26 insertions(+), 2 deletions(-)

diff --git a/[refs] b/[refs]
index 2e5c02f82213..34de8f34f8fc 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 17099b1142f6c0359fca60a3464dea8fb30badea
+refs/heads/master: 5a81299928f3d9abfaced60bedd85214cf9921a4
diff --git a/trunk/arch/mips/kernel/cpu-probe.c b/trunk/arch/mips/kernel/cpu-probe.c
index c6b8b074a81a..06448a9656dc 100644
--- a/trunk/arch/mips/kernel/cpu-probe.c
+++ b/trunk/arch/mips/kernel/cpu-probe.c
@@ -75,6 +75,27 @@ static void r4k_wait_irqoff(void)
 	local_irq_enable();
 }
 
+/*
+ * The RM7000 variant has to handle erratum 38.  The workaround is to not
+ * have any pending stores when the WAIT instruction is executed.
+ */
+static void rm7k_wait_irqoff(void)
+{
+	local_irq_disable();
+	if (!need_resched())
+		__asm__(
+		"	.set	push					\n"
+		"	.set	mips3					\n"
+		"	.set	noat					\n"
+		"	mfc0	$1, $12					\n"
+		"	sync						\n"
+		"	mtc0	$1, $12		# stalls until W stage	\n"
+		"	wait						\n"
+		"	mtc0	$1, $12		# stalls until W stage	\n"
+		"	.set	pop					\n");
+	local_irq_enable();
+}
+
 /* The Au1xxx wait is available only if using 32khz counter or
  * external timer source, but specifically not CP0 Counter. */
 int allow_au1k_wait;
@@ -132,7 +153,6 @@ static inline void check_wait(void)
 	case CPU_R4700:
 	case CPU_R5000:
 	case CPU_NEVADA:
-	case CPU_RM7000:
 	case CPU_4KC:
 	case CPU_4KEC:
 	case CPU_4KSC:
@@ -142,6 +162,10 @@ static inline void check_wait(void)
 		cpu_wait = r4k_wait;
 		break;
 
+	case CPU_RM7000:
+		cpu_wait = rm7k_wait_irqoff;
+		break;
+
 	case CPU_24K:
 	case CPU_34K:
 		cpu_wait = r4k_wait;