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arm64: psci: move psci firmware calls out of line 

An arm64 allmodconfig fails to build with GCC 5 due to __asmeq
assertions in the PSCI firmware calling code firing due to mcount
preambles breaking our assumptions about register allocation of function
arguments:

  /tmp/ccDqJsJ6.s: Assembler messages:
  /tmp/ccDqJsJ6.s:60: Error: .err encountered
  /tmp/ccDqJsJ6.s:61: Error: .err encountered
  /tmp/ccDqJsJ6.s:62: Error: .err encountered
  /tmp/ccDqJsJ6.s:99: Error: .err encountered
  /tmp/ccDqJsJ6.s💯 Error: .err encountered
  /tmp/ccDqJsJ6.s:101: Error: .err encountered

This patch fixes the issue by moving the PSCI calls out-of-line into
their own assembly files, which are safe from the compiler's meddling
fingers.

Reported-by: Andy Whitcroft <apw@canonical.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
This commit is contained in:
Will Deacon 2015-02-25 12:10:35 +00:00 committed by Catalin Marinas
parent e1b6b6ce55
commit f5e0a12ca2
3 changed files with 34 additions and 36 deletions
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5
arch/arm64/kernel/Makefile
View File

@ -15,8 +15,9 @@ CFLAGS_REMOVE_return_address.o = -pg
arm64-obj-y := cputable.o debug-monitors.o entry.o irq.o fpsimd.o \
entry-fpsimd.o process.o ptrace.o setup.o signal.o \
sys.o stacktrace.o time.o traps.o io.o vdso.o \
hyp-stub.o psci.o cpu_ops.o insn.o return_address.o \
cpuinfo.o cpu_errata.o alternative.o cacheinfo.o
hyp-stub.o psci.o psci-call.o cpu_ops.o insn.o \
return_address.o cpuinfo.o cpu_errata.o \
alternative.o cacheinfo.o
arm64-obj-$(CONFIG_COMPAT) += sys32.o kuser32.o signal32.o \
sys_compat.o entry32.o \

28
arch/arm64/kernel/psci-call.S Normal file
View File

@ -0,0 +1,28 @@
/*
* 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: Will Deacon <will.deacon@arm.com>
*/
#include <linux/linkage.h>
/* int __invoke_psci_fn_hvc(u64 function_id, u64 arg0, u64 arg1, u64 arg2) */
ENTRY(__invoke_psci_fn_hvc)
hvc #0
ret
ENDPROC(__invoke_psci_fn_hvc)
/* int __invoke_psci_fn_smc(u64 function_id, u64 arg0, u64 arg1, u64 arg2) */
ENTRY(__invoke_psci_fn_smc)
smc #0
ret
ENDPROC(__invoke_psci_fn_smc)

37
arch/arm64/kernel/psci.c
View File

@ -57,6 +57,9 @@ static struct psci_operations psci_ops;
static int (*invoke_psci_fn)(u64, u64, u64, u64);
typedef int (*psci_initcall_t)(const struct device_node *);
asmlinkage int __invoke_psci_fn_hvc(u64, u64, u64, u64);
asmlinkage int __invoke_psci_fn_smc(u64, u64, u64, u64);
enum psci_function {
PSCI_FN_CPU_SUSPEND,
PSCI_FN_CPU_ON,
@ -109,40 +112,6 @@ static void psci_power_state_unpack(u32 power_state,
PSCI_0_2_POWER_STATE_AFFL_SHIFT;
}
/*
* 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(u64 function_id, u64 arg0, u64 arg1,
u64 arg2)
{
asm volatile(
__asmeq("%0", "x0")
__asmeq("%1", "x1")
__asmeq("%2", "x2")
__asmeq("%3", "x3")
"hvc #0\n"
: "+r" (function_id)
: "r" (arg0), "r" (arg1), "r" (arg2));
return function_id;
}
static noinline int __invoke_psci_fn_smc(u64 function_id, u64 arg0, u64 arg1,
u64 arg2)
{
asm volatile(
__asmeq("%0", "x0")
__asmeq("%1", "x1")
__asmeq("%2", "x2")
__asmeq("%3", "x3")
"smc #0\n"
: "+r" (function_id)
: "r" (arg0), "r" (arg1), "r" (arg2));
return function_id;
}
static int psci_get_version(void)
{
int err;