ARM: tegra: power: Prefer movw/movt for loading addresses

The movw/movt instruction pair (encapsulated by the mov32 macro)
is preferred over literals for loading addresses. The use of literals
for singleton data accesses can cause unnecessary cache misses and
evictions for cache lines that are unlikely to be accessed again in
the near future. Furthermore, certain code sequences must refrain
from using data accesses. Therefore, in general, addresses should
be loaded by mov32.

Change-Id: I9bcc3ee191f882996197ce2edc0eb510d4ff7b4a
Reviewed-on: http://git-master/r/40460
Tested-by: Daniel Willemsen <dwillemsen@nvidia.com>
Reviewed-by: Scott Williams <scwilliams@nvidia.com>
Reviewed-by: Daniel Willemsen <dwillemsen@nvidia.com>

Rebase-Id: R7ddd0d9b1e2fc8ab653b9220388acbecdbf4c57f

1 files changed, 53 insertions, 0 deletions

diff --git a/arch/arm/mach-tegra/asm_macros.h b/arch/arm/mach-tegra/asm_macros.h
new file mode 100644
index 000000000000..24d1449efbae
--- /dev/null
+++ b/arch/arm/mach-tegra/asm_macros.h
@@ -0,0 +1,53 @@
+/*
+ * arch/arm/mach-tegra/include/mach/asm_macros.h
+ *
+ * Copyright (C) 2011 NVIDIA Corporation
+ *
+ * This software is licensed under the terms of the GNU General Public
+ * License version 2, as published by the Free Software Foundation, and
+ * may be copied, distributed, and modified under those terms.
+ *
+ * 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.
+ *
+ */
+
+#ifndef _MACH_TEGRA_ASM_MACROS_H_
+#define _MACH_TEGRA_ASM_MACROS_H_
+
+#ifdef __ASSEMBLY__
+
+/* returns the offset of the flow controller halt register for a cpu */
+.macro cpu_to_halt_reg rd, rcpu
+	cmp	\rcpu, #0
+	subne	\rd, \rcpu, #1
+	movne	\rd, \rd, lsl #3
+	addne	\rd, \rd, #0x14
+	moveq	\rd, #0
+.endm
+
+/* returns the offset of the flow controller csr register for a cpu */
+.macro cpu_to_csr_reg rd, rcpu
+	cmp	\rcpu, #0
+	subne	\rd, \rcpu, #1
+	movne	\rd, \rd, lsl #3
+	addne	\rd, \rd, #0x18
+	moveq	\rd, #8
+.endm
+
+/* returns the ID of the current processor */
+.macro cpu_id, rd
+	mrc	p15, 0, \rd, c0, c0, 5
+	and	\rd, \rd, #0xF
+.endm
+
+/* loads a 32-bit value into a register without a data access */
+.macro mov32, reg, val
+	movw	\reg, #:lower16:\val
+	movt	\reg, #:upper16:\val
+.endm
+
+#endif
+#endif