[linux-yocto] [PATCH] arm64: psci: move psci firmware calls out of line

[akuster808]

On 05/18/2015 08:19 PM, Bruce Ashfield wrote:
> Dropping the non-yocto interested parties from my reply, looks
> like you git-send-email was picking up cc: folks.

Yeah, not intended. thought "-a" did that which I did not use.

>
> Obviously this is for ARM and gcc5 ... but my question is, with
> this, what do we have ? ARM building with gcc5 ?

Arm64 builds poky core-image-minimal. qemuarm64 boots

>
> And to confirm, this is for 3.19 ? or 3.14 ?

3.19. Have not gotten around to 3.14.

- Armin

> Bruce
>
> On 2015-05-16 12:07 PM, Armin Kuster wrote:
>> From: Will Deacon <will.deacon at arm.com>
>>
>> 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:100: 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 at canonical.com>
>> Signed-off-by: Will Deacon <will.deacon at arm.com>
>> Signed-off-by: Catalin Marinas <catalin.marinas at arm.com>
>> Signed-off-by: Armin Kuter <akuster at mvista.com>
>> ---
>>   arch/arm64/kernel/Makefile    |  6 ++++--
>>   arch/arm64/kernel/psci-call.S | 28 ++++++++++++++++++++++++++++
>>   arch/arm64/kernel/psci.c      | 37
>> +++----------------------------------
>>   3 files changed, 35 insertions(+), 36 deletions(-)
>>   create mode 100644 arch/arm64/kernel/psci-call.S
>>
>> diff --git a/arch/arm64/kernel/Makefile b/arch/arm64/kernel/Makefile
>> index eaa77ed..c8e9adc 100644
>> --- a/arch/arm64/kernel/Makefile
>> +++ b/arch/arm64/kernel/Makefile
>> @@ -15,8 +15,10 @@ 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
>> +               hyp-stub.o psci.o psci-call.o cpu_ops.o insn.o       \
>> +                           return_address.o cpuinfo.o
>> cpu_errata.o              \
>> +                           alternative.o
>> +
>>
>>   arm64-obj-$(CONFIG_COMPAT)        += sys32.o kuser32.o signal32.o     \
>>                          sys_compat.o             \
>> diff --git a/arch/arm64/kernel/psci-call.S
>> b/arch/arm64/kernel/psci-call.S
>> new file mode 100644
>> index 0000000..cf83e61
>> --- /dev/null
>> +++ b/arch/arm64/kernel/psci-call.S
>> @@ -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 at 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)
>> diff --git a/arch/arm64/kernel/psci.c b/arch/arm64/kernel/psci.c
>> index f1dbca7..38c12f4 100644
>> --- a/arch/arm64/kernel/psci.c
>> +++ b/arch/arm64/kernel/psci.c
>> @@ -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;
>>
>