[POWERPC] pasemi: Idle loops

Powersave support on PA6T. Right now it only uses 'doze' mode, and
will default to no savings (spin).

Signed-off-by: Olof Johansson <olof@lixom.net>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Paul Mackerras <paulus@samba.org>

1 files changed, 80 insertions, 0 deletions

diff --git a/arch/powerpc/platforms/pasemi/powersave.S b/arch/powerpc/platforms/pasemi/powersave.S
new file mode 100644
index 000000000000..6d0fba6aab17
--- /dev/null
+++ b/arch/powerpc/platforms/pasemi/powersave.S
@@ -0,0 +1,80 @@
+/*
+ * Copyright (C) 2006-2007 PA Semi, Inc
+ *
+ * Maintained by: Olof Johansson <olof@lixom.net>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
+ *
+ */
+
+#include <asm/processor.h>
+#include <asm/page.h>
+#include <asm/ppc_asm.h>
+#include <asm/cputable.h>
+#include <asm/cache.h>
+#include <asm/thread_info.h>
+#include <asm/asm-offsets.h>
+
+/* Power savings opcodes since not all binutils have them at this time */
+#define DOZE    .long   0x4c000324
+#define NAP     .long   0x4c000364
+#define SLEEP   .long   0x4c0003a4
+#define RVW     .long   0x4c0003e4
+
+/* Common sequence to do before going to any of the
+ * powersavings modes.
+ */
+
+#define PRE_SLEEP_SEQUENCE      \
+        std     r3,8(r1);       \
+        ptesync ;               \
+        ld      r3,8(r1);       \
+1:      cmpd    r3,r3;          \
+        bne     1b
+
+_doze:
+        PRE_SLEEP_SEQUENCE
+        DOZE
+        b       .
+
+
+_GLOBAL(idle_spin)
+        blr
+
+_GLOBAL(idle_doze)
+        LOAD_REG_ADDR(r3, _doze)
+        b       sleep_common
+
+/* Add more modes here later */
+
+sleep_common:
+        mflr    r0
+        std     r0, 16(r1)
+        stdu    r1,-64(r1)
+
+        LOAD_REG_IMMEDIATE(r6,MSR_DR|MSR_IR|MSR_ME|MSR_EE)
+        mfmsr   r4
+        andc    r5,r4,r6
+        mtmsrd  r5,0
+
+        mtctr   r3
+        bctrl
+
+        mtmsrd  r4,0
+
+        addi    r1,r1,64
+        ld      r0,16(r1)
+        mtlr    r0
+        blr
+