[PATCH 2/2] ARM: psci: move psci firmware calls out of line

[will.deacon@arm.com (Will Deacon)]

From: Mark Rutland <mark.rutland@arm.com>

arm64 builds with GCC 5 have caused the __asmeq assertions in the PSCI
calling code to fire, so move the ARM PSCI calls out of line into their
own assembly file for consistency and to safeguard against the same
issue occuring with the 32-bit toolchain.

Reported-by: Andy Whitcroft <apw@canonical.com>
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
[will: brought into line with arm64 implementation]
Signed-off-by: Will Deacon <will.deacon@arm.com>
---
 arch/arm/kernel/Makefile    |  2 +-
 arch/arm/kernel/psci-call.S | 31 +++++++++++++++++++++++++++++++
 arch/arm/kernel/psci.c      | 39 +++------------------------------------
 3 files changed, 35 insertions(+), 37 deletions(-)
 create mode 100644 arch/arm/kernel/psci-call.S

diff --git a/arch/arm/kernel/Makefile b/arch/arm/kernel/Makefile
index 902397dd1000..1c1cdfa566ac 100644
--- a/arch/arm/kernel/Makefile
+++ b/arch/arm/kernel/Makefile
@@ -86,7 +86,7 @@ obj-$(CONFIG_EARLY_PRINTK)	+= early_printk.o
 
 obj-$(CONFIG_ARM_VIRT_EXT)	+= hyp-stub.o
 ifeq ($(CONFIG_ARM_PSCI),y)
-obj-y				+= psci.o
+obj-y				+= psci.o psci-call.o
 obj-$(CONFIG_SMP)		+= psci_smp.o
 endif
 
diff --git a/arch/arm/kernel/psci-call.S b/arch/arm/kernel/psci-call.S
new file mode 100644
index 000000000000..a78e9e1e206d
--- /dev/null
+++ b/arch/arm/kernel/psci-call.S
@@ -0,0 +1,31 @@
+/*
+ * 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.
+ *
+ * Copyright (C) 2015 ARM Limited
+ *
+ * Author: Mark Rutland <mark.rutland@arm.com>
+ */
+
+#include <linux/linkage.h>
+
+#include <asm/opcodes-sec.h>
+#include <asm/opcodes-virt.h>
+
+/* int __invoke_psci_fn_hvc(u32 function_id, u32 arg0, u32 arg1, u32 arg2) */
+ENTRY(__invoke_psci_fn_hvc)
+	__HVC(0)
+	bx	lr
+ENDPROC(__invoke_psci_fn_hvc)
+
+/* int __invoke_psci_fn_smc(u32 function_id, u32 arg0, u32 arg1, u32 arg2) */
+ENTRY(__invoke_psci_fn_smc)
+	__SMC(0)
+	bx	lr
+ENDPROC(__invoke_psci_fn_smc)
diff --git a/arch/arm/kernel/psci.c b/arch/arm/kernel/psci.c
index f73891b6b730..f90fdf4ce7c7 100644
--- a/arch/arm/kernel/psci.c
+++ b/arch/arm/kernel/psci.c
@@ -23,8 +23,6 @@
 
 #include <asm/compiler.h>
 #include <asm/errno.h>
-#include <asm/opcodes-sec.h>
-#include <asm/opcodes-virt.h>
 #include <asm/psci.h>
 #include <asm/system_misc.h>
 
@@ -33,6 +31,9 @@ struct psci_operations psci_ops;
 static int (*invoke_psci_fn)(u32, u32, u32, u32);
 typedef int (*psci_initcall_t)(const struct device_node *);
 
+asmlinkage int __invoke_psci_fn_hvc(u32, u32, u32, u32);
+asmlinkage int __invoke_psci_fn_smc(u32, u32, u32, u32);
+
 enum psci_function {
 	PSCI_FN_CPU_SUSPEND,
 	PSCI_FN_CPU_ON,
@@ -71,40 +72,6 @@ static u32 psci_power_state_pack(struct psci_power_state state)
 		 & PSCI_0_2_POWER_STATE_AFFL_MASK);
 }
 
-/*
- * The following two functions are invoked via the invoke_psci_fn pointer
- * and will not be inlined, allowing us to piggyback on the AAPCS.
- */
-static noinline int __invoke_psci_fn_hvc(u32 function_id, u32 arg0, u32 arg1,
-					 u32 arg2)
-{
-	asm volatile(
-			__asmeq("%0", "r0")
-			__asmeq("%1", "r1")
-			__asmeq("%2", "r2")
-			__asmeq("%3", "r3")
-			__HVC(0)
-		: "+r" (function_id)
-		: "r" (arg0), "r" (arg1), "r" (arg2));
-
-	return function_id;
-}
-
-static noinline int __invoke_psci_fn_smc(u32 function_id, u32 arg0, u32 arg1,
-					 u32 arg2)
-{
-	asm volatile(
-			__asmeq("%0", "r0")
-			__asmeq("%1", "r1")
-			__asmeq("%2", "r2")
-			__asmeq("%3", "r3")
-			__SMC(0)
-		: "+r" (function_id)
-		: "r" (arg0), "r" (arg1), "r" (arg2));
-
-	return function_id;
-}
-
 static int psci_get_version(void)
 {
 	int err;
-- 
2.1.4