From dfade4c0a4eeea8b2b6af8a9869da83d5bb6e1d0 Mon Sep 17 00:00:00 2001
From: Marius Strobl <marius@FreeBSD.org>
Date: Sat, 13 Feb 2010 15:36:33 +0000
Subject: [PATCH] - At least the trap table of the Sun Fire V1280 firmware
 apparently has   no cleanwindows handler so just remove trying to trigger it
 from _start   and the AP trampoline code as that leads to a crash there. This
 should   be okay as leaking data from the OFW via the CPU registers on start
 of   the kernel should be no real concern. - Make the comments of _start and
 the AP trampoline code regarding the   initializations they perform match
 each other and reality. - Make the comments of the AP trampoline code
 regarding iTLB accesses   refer to the right macro.

---
 sys/sparc64/sparc64/locore.S    |  8 +++++---
 sys/sparc64/sparc64/mp_locore.S | 16 +++++++++-------
 2 files changed, 14 insertions(+), 10 deletions(-)

diff --git a/sys/sparc64/sparc64/locore.S b/sys/sparc64/sparc64/locore.S
index 8c1043e406f2..ac6659b5c977 100644
--- a/sys/sparc64/sparc64/locore.S
+++ b/sys/sparc64/sparc64/locore.S
@@ -46,12 +46,14 @@ ENTRY(btext)
 ENTRY(_start)
 	/*
 	 * Initialize misc. state to known values: interrupts disabled, normal
-	 * globals, windows flushed (cr = 0, cs = nwindows - 1), no clean
-	 * windows, pil 0, and floating point disabled.
+	 * globals, windows flushed (cr = 0, cs = nwindows - 1), PIL 0 and
+	 * floating point disabled.
+	 * Note that some firmware versions don't implement a clean window
+	 * trap handler so we unfortunately can't clear the windows by setting
+	 * %cleanwin to zero here.
 	 */
 	wrpr	%g0, PSTATE_NORMAL, %pstate
 	flushw
-	wrpr	%g0, 0, %cleanwin
 	wrpr	%g0, 0, %pil
 	wr	%g0, 0, %fprs
 
diff --git a/sys/sparc64/sparc64/mp_locore.S b/sys/sparc64/sparc64/mp_locore.S
index e8b2a9526335..b089a2ba9cfc 100644
--- a/sys/sparc64/sparc64/mp_locore.S
+++ b/sys/sparc64/sparc64/mp_locore.S
@@ -44,12 +44,14 @@ __FBSDID("$FreeBSD$");
 	.text
 	_ALIGN_TEXT
 	/*
-	 * Initialize misc. state to known values: interrupts disabled,
-	 * normal globals, no clean windows, PIL 0, and floating point
-	 * disabled.
+	 * Initialize misc. state to known values: interrupts disabled, normal
+	 * globals, windows flushed (cr = 0, cs = nwindows - 1), PIL 0 and
+	 * floating point disabled.
+	 * Note that some firmware versions don't implement a clean window
+	 * trap handler so we unfortunately can't clear the windows by setting
+	 * %cleanwin to zero here.
 	 */
 1:	wrpr	%g0, PSTATE_NORMAL, %pstate
-	wrpr	%g0, 0, %cleanwin
 	wrpr	%g0, 0, %pil
 	wr	%g0, 0, %fprs
 
@@ -68,7 +70,7 @@ __FBSDID("$FreeBSD$");
 
 	setx	TD_V | TD_L, %l1, %l0
 	/*
-	 * We read ASI_DTLB_DATA_ACCESS_REG twice in order to work
+	 * We read ASI_ITLB_DATA_ACCESS_REG twice in order to work
 	 * around errata of USIII and beyond.
 	 */
 	ldxa	[%g0] ASI_ITLB_DATA_ACCESS_REG, %g0
@@ -94,7 +96,7 @@ __FBSDID("$FreeBSD$");
 	mov	(1 << TLB_DAR_SLOT_SHIFT), %l4
 	setx	TD_V, %l1, %l0
 	/*
-	 * We read ASI_DTLB_DATA_ACCESS_REG twice in order to work
+	 * We read ASI_ITLB_DATA_ACCESS_REG twice in order to work
 	 * around errata of USIII and beyond.
 	 */
 2:	ldxa	[%l4] ASI_ITLB_DATA_ACCESS_REG, %g0
@@ -136,7 +138,7 @@ __FBSDID("$FreeBSD$");
 	mov	(1 << TLB_DAR_SLOT_SHIFT), %l0
 	setx	TD_V, %o1, %o0
 	/*
-	 * We read ASI_DTLB_DATA_ACCESS_REG twice in order to work
+	 * We read ASI_ITLB_DATA_ACCESS_REG twice in order to work
 	 * around errata of USIII and beyond.
 	 */
 5:	ldxa	[%l0] ASI_ITLB_DATA_ACCESS_REG, %g0