[Xen-devel,[PATCH,v3] 4/4] xen/arm: Replace call_smc with arm_smccc_smc

Message ID 20181001124639.22885-5-julien.grall@arm.com
State Accepted
Commit 0bc6a68da585cb5d781f27404943a1dbd393e95f
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Series
  • [Xen-devel,[PATCH,v3] 4/4] xen/arm: Replace call_smc with arm_smccc_smc
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Commit Message

Julien Grall Oct. 1, 2018, 12:46 p.m.
call_smc is a subset of arm_smccc_smc. Rather than having 2 methods to
do SMCCC call, replace all call to the former by the later.

Signed-off-by: Julien Grall <julien.grall@arm.com>

---

    Changes in v3:
        - Use PSCI_RET where needed
---
 xen/arch/arm/Makefile            |  1 -
 xen/arch/arm/platforms/exynos5.c |  3 ++-
 xen/arch/arm/platforms/seattle.c |  4 ++--
 xen/arch/arm/psci.c              | 37 +++++++++++++++++++++++++------------
 xen/arch/arm/smc.S               | 21 ---------------------
 xen/include/asm-arm/processor.h  |  3 ---
 6 files changed, 29 insertions(+), 40 deletions(-)
 delete mode 100644 xen/arch/arm/smc.S

Comments

Andrew Cooper Oct. 1, 2018, 1:11 p.m. | #1
On 01/10/18 13:46, Julien Grall wrote:
> call_smc is a subset of arm_smccc_smc. Rather than having 2 methods to
> do SMCCC call, replace all call to the former by the later.
>
> Signed-off-by: Julien Grall <julien.grall@arm.com>
>
> ---
>
>     Changes in v3:
>         - Use PSCI_RET where needed
> ---
>  xen/arch/arm/Makefile            |  1 -
>  xen/arch/arm/platforms/exynos5.c |  3 ++-
>  xen/arch/arm/platforms/seattle.c |  4 ++--
>  xen/arch/arm/psci.c              | 37 +++++++++++++++++++++++++------------
>  xen/arch/arm/smc.S               | 21 ---------------------
>  xen/include/asm-arm/processor.h  |  3 ---
>  6 files changed, 29 insertions(+), 40 deletions(-)
>  delete mode 100644 xen/arch/arm/smc.S
>
> diff --git a/xen/arch/arm/Makefile b/xen/arch/arm/Makefile
> index b9b141dc84..37fa8268b3 100644
> --- a/xen/arch/arm/Makefile
> +++ b/xen/arch/arm/Makefile
> @@ -39,7 +39,6 @@ obj-y += processor.o
>  obj-y += psci.o
>  obj-y += setup.o
>  obj-y += shutdown.o
> -obj-y += smc.o
>  obj-y += smp.o
>  obj-y += smpboot.o
>  obj-y += sysctl.o
> diff --git a/xen/arch/arm/platforms/exynos5.c b/xen/arch/arm/platforms/exynos5.c
> index c15ecf80f5..e2c0b7b878 100644
> --- a/xen/arch/arm/platforms/exynos5.c
> +++ b/xen/arch/arm/platforms/exynos5.c
> @@ -26,6 +26,7 @@
>  #include <asm/platforms/exynos5.h>
>  #include <asm/platform.h>
>  #include <asm/io.h>
> +#include <asm/smccc.h>
>  
>  static bool secure_firmware;
>  
> @@ -249,7 +250,7 @@ static int exynos5_cpu_up(int cpu)
>      iounmap(power);
>  
>      if ( secure_firmware )
> -        call_smc(SMC_CMD_CPU1BOOT, cpu, 0, 0);
> +        arm_smccc_smc(SMC_CMD_CPU1BOOT, cpu, NULL);
>  
>      return cpu_up_send_sgi(cpu);
>  }
> diff --git a/xen/arch/arm/platforms/seattle.c b/xen/arch/arm/platforms/seattle.c
> index 893cc17972..64cc1868c2 100644
> --- a/xen/arch/arm/platforms/seattle.c
> +++ b/xen/arch/arm/platforms/seattle.c
> @@ -33,12 +33,12 @@ static const char * const seattle_dt_compat[] __initconst =
>   */
>  static void seattle_system_reset(void)
>  {
> -    call_smc(PSCI_0_2_FN32_SYSTEM_RESET, 0, 0, 0);
> +    arm_smccc_smc(PSCI_0_2_FN32_SYSTEM_RESET, NULL);
>  }
>  
>  static void seattle_system_off(void)
>  {
> -    call_smc(PSCI_0_2_FN32_SYSTEM_OFF, 0, 0, 0);
> +    arm_smccc_smc(PSCI_0_2_FN32_SYSTEM_OFF, NULL);
>  }
>  
>  PLATFORM_START(seattle, "SEATTLE")
> diff --git a/xen/arch/arm/psci.c b/xen/arch/arm/psci.c
> index 941eec921b..4ae6504f3e 100644
> --- a/xen/arch/arm/psci.c
> +++ b/xen/arch/arm/psci.c
> @@ -42,42 +42,53 @@ uint32_t smccc_ver;
>  
>  static uint32_t psci_cpu_on_nr;
>  
> +#define PSCI_RET(res)   ((int32_t)(res).a0)
> +
>  int call_psci_cpu_on(int cpu)
>  {
> -    return call_smc(psci_cpu_on_nr, cpu_logical_map(cpu), __pa(init_secondary), 0);
> +    struct arm_smccc_res res;
> +
> +    arm_smccc_smc(psci_cpu_on_nr, cpu_logical_map(cpu), __pa(init_secondary),
> +                  &res);
> +
> +    return PSCI_RET(res.a0);
>  }

Sorry if I'm jumping into the middle of a conversation, but why force
all callers to manually extract the return value when it is a fixed
register?

Wouldn't it be far easier to do this:

#define arcm_smccc_smc(...)                         \
    ({                                              \
        struct arm_smccc_res res;                   \
                                                    \
        if ( cpus_have_const_cap(ARM_SMCCC_1_1) )   \
            res = arm_smccc_1_1_smc(__VA_ARGS__);   \
        else                                        \
            res = arm_smccc_1_0_smc(__VA_ARGS__);   \
                                                    \
        (int)res.a0;                                \
    })

Which also allows the compiler to optimise out the structure if it isn't
read, and also avoids the caller needing to pass a NULL pointer for "I
don't want the result".

~Andrew
Julien Grall Oct. 1, 2018, 1:13 p.m. | #2
Hi,

On 10/01/2018 01:46 PM, Julien Grall wrote:
>   PLATFORM_START(seattle, "SEATTLE")
> diff --git a/xen/arch/arm/psci.c b/xen/arch/arm/psci.c
> index 941eec921b..4ae6504f3e 100644
> --- a/xen/arch/arm/psci.c
> +++ b/xen/arch/arm/psci.c
> @@ -42,42 +42,53 @@ uint32_t smccc_ver;
>   
>   static uint32_t psci_cpu_on_nr;
>   
> +#define PSCI_RET(res)   ((int32_t)(res).a0)
> +
>   int call_psci_cpu_on(int cpu)
>   {
> -    return call_smc(psci_cpu_on_nr, cpu_logical_map(cpu), __pa(init_secondary), 0);
> +    struct arm_smccc_res res;
> +
> +    arm_smccc_smc(psci_cpu_on_nr, cpu_logical_map(cpu), __pa(init_secondary),
> +                  &res);
> +
> +    return PSCI_RET(res.a0);

Hmmm this should have been PSCI_RET(res). I guess this could be fixed if 
not other change.

Cheers,
Julien Grall Oct. 1, 2018, 1:33 p.m. | #3
Hi Andrew,

On 10/01/2018 02:11 PM, Andrew Cooper wrote:
> On 01/10/18 13:46, Julien Grall wrote:
>> call_smc is a subset of arm_smccc_smc. Rather than having 2 methods to
>> do SMCCC call, replace all call to the former by the later.
>>
>> Signed-off-by: Julien Grall <julien.grall@arm.com>
>>
>> ---
>>
>>      Changes in v3:
>>          - Use PSCI_RET where needed
>> ---
>>   xen/arch/arm/Makefile            |  1 -
>>   xen/arch/arm/platforms/exynos5.c |  3 ++-
>>   xen/arch/arm/platforms/seattle.c |  4 ++--
>>   xen/arch/arm/psci.c              | 37 +++++++++++++++++++++++++------------
>>   xen/arch/arm/smc.S               | 21 ---------------------
>>   xen/include/asm-arm/processor.h  |  3 ---
>>   6 files changed, 29 insertions(+), 40 deletions(-)
>>   delete mode 100644 xen/arch/arm/smc.S
>>
>> diff --git a/xen/arch/arm/Makefile b/xen/arch/arm/Makefile
>> index b9b141dc84..37fa8268b3 100644
>> --- a/xen/arch/arm/Makefile
>> +++ b/xen/arch/arm/Makefile
>> @@ -39,7 +39,6 @@ obj-y += processor.o
>>   obj-y += psci.o
>>   obj-y += setup.o
>>   obj-y += shutdown.o
>> -obj-y += smc.o
>>   obj-y += smp.o
>>   obj-y += smpboot.o
>>   obj-y += sysctl.o
>> diff --git a/xen/arch/arm/platforms/exynos5.c b/xen/arch/arm/platforms/exynos5.c
>> index c15ecf80f5..e2c0b7b878 100644
>> --- a/xen/arch/arm/platforms/exynos5.c
>> +++ b/xen/arch/arm/platforms/exynos5.c
>> @@ -26,6 +26,7 @@
>>   #include <asm/platforms/exynos5.h>
>>   #include <asm/platform.h>
>>   #include <asm/io.h>
>> +#include <asm/smccc.h>
>>   
>>   static bool secure_firmware;
>>   
>> @@ -249,7 +250,7 @@ static int exynos5_cpu_up(int cpu)
>>       iounmap(power);
>>   
>>       if ( secure_firmware )
>> -        call_smc(SMC_CMD_CPU1BOOT, cpu, 0, 0);
>> +        arm_smccc_smc(SMC_CMD_CPU1BOOT, cpu, NULL);
>>   
>>       return cpu_up_send_sgi(cpu);
>>   }
>> diff --git a/xen/arch/arm/platforms/seattle.c b/xen/arch/arm/platforms/seattle.c
>> index 893cc17972..64cc1868c2 100644
>> --- a/xen/arch/arm/platforms/seattle.c
>> +++ b/xen/arch/arm/platforms/seattle.c
>> @@ -33,12 +33,12 @@ static const char * const seattle_dt_compat[] __initconst =
>>    */
>>   static void seattle_system_reset(void)
>>   {
>> -    call_smc(PSCI_0_2_FN32_SYSTEM_RESET, 0, 0, 0);
>> +    arm_smccc_smc(PSCI_0_2_FN32_SYSTEM_RESET, NULL);
>>   }
>>   
>>   static void seattle_system_off(void)
>>   {
>> -    call_smc(PSCI_0_2_FN32_SYSTEM_OFF, 0, 0, 0);
>> +    arm_smccc_smc(PSCI_0_2_FN32_SYSTEM_OFF, NULL);
>>   }
>>   
>>   PLATFORM_START(seattle, "SEATTLE")
>> diff --git a/xen/arch/arm/psci.c b/xen/arch/arm/psci.c
>> index 941eec921b..4ae6504f3e 100644
>> --- a/xen/arch/arm/psci.c
>> +++ b/xen/arch/arm/psci.c
>> @@ -42,42 +42,53 @@ uint32_t smccc_ver;
>>   
>>   static uint32_t psci_cpu_on_nr;
>>   
>> +#define PSCI_RET(res)   ((int32_t)(res).a0)
>> +
>>   int call_psci_cpu_on(int cpu)
>>   {
>> -    return call_smc(psci_cpu_on_nr, cpu_logical_map(cpu), __pa(init_secondary), 0);
>> +    struct arm_smccc_res res;
>> +
>> +    arm_smccc_smc(psci_cpu_on_nr, cpu_logical_map(cpu), __pa(init_secondary),
>> +                  &res);
>> +
>> +    return PSCI_RET(res.a0);
>>   }
> 
> Sorry if I'm jumping into the middle of a conversation, but why force
> all callers to manually extract the return value when it is a fixed
> register?

The SMCCC allows up to 4 return value (a0 ... a3). At the moment, most 
of the caller in Xen only care about one result value. But this will 
change soon (see OP-TEE support in Xen).

> 
> Wouldn't it be far easier to do this:
> 
> #define arcm_smccc_smc(...)                         \
>      ({                                              \
>          struct arm_smccc_res res;                   \
>                                                      \
>          if ( cpus_have_const_cap(ARM_SMCCC_1_1) )   \
>              res = arm_smccc_1_1_smc(__VA_ARGS__);   \
>          else                                        \
>              res = arm_smccc_1_0_smc(__VA_ARGS__);   \
>                                                      \
>          (int)res.a0;                                \

We can't possibly cast here. The interpretation of a0 is different from 
one call to another.

>      })
> 
> Which also allows the compiler to optimise out the structure if it isn't
> read, and also avoids the caller needing to pass a NULL pointer for "I
> don't want the result".

While I understand the value, I don't think this would be correct if we 
want to implement an interface with the SMCCC.

Cheers,
Stefano Stabellini Oct. 1, 2018, 8:01 p.m. | #4
On Mon, 1 Oct 2018, Julien Grall wrote:
> call_smc is a subset of arm_smccc_smc. Rather than having 2 methods to
> do SMCCC call, replace all call to the former by the later.
> 
> Signed-off-by: Julien Grall <julien.grall@arm.com>

Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>

(you might want to make sure the double [[ is removed on commit.)

> ---
> 
>     Changes in v3:
>         - Use PSCI_RET where needed
> ---
>  xen/arch/arm/Makefile            |  1 -
>  xen/arch/arm/platforms/exynos5.c |  3 ++-
>  xen/arch/arm/platforms/seattle.c |  4 ++--
>  xen/arch/arm/psci.c              | 37 +++++++++++++++++++++++++------------
>  xen/arch/arm/smc.S               | 21 ---------------------
>  xen/include/asm-arm/processor.h  |  3 ---
>  6 files changed, 29 insertions(+), 40 deletions(-)
>  delete mode 100644 xen/arch/arm/smc.S
> 
> diff --git a/xen/arch/arm/Makefile b/xen/arch/arm/Makefile
> index b9b141dc84..37fa8268b3 100644
> --- a/xen/arch/arm/Makefile
> +++ b/xen/arch/arm/Makefile
> @@ -39,7 +39,6 @@ obj-y += processor.o
>  obj-y += psci.o
>  obj-y += setup.o
>  obj-y += shutdown.o
> -obj-y += smc.o
>  obj-y += smp.o
>  obj-y += smpboot.o
>  obj-y += sysctl.o
> diff --git a/xen/arch/arm/platforms/exynos5.c b/xen/arch/arm/platforms/exynos5.c
> index c15ecf80f5..e2c0b7b878 100644
> --- a/xen/arch/arm/platforms/exynos5.c
> +++ b/xen/arch/arm/platforms/exynos5.c
> @@ -26,6 +26,7 @@
>  #include <asm/platforms/exynos5.h>
>  #include <asm/platform.h>
>  #include <asm/io.h>
> +#include <asm/smccc.h>
>  
>  static bool secure_firmware;
>  
> @@ -249,7 +250,7 @@ static int exynos5_cpu_up(int cpu)
>      iounmap(power);
>  
>      if ( secure_firmware )
> -        call_smc(SMC_CMD_CPU1BOOT, cpu, 0, 0);
> +        arm_smccc_smc(SMC_CMD_CPU1BOOT, cpu, NULL);
>  
>      return cpu_up_send_sgi(cpu);
>  }
> diff --git a/xen/arch/arm/platforms/seattle.c b/xen/arch/arm/platforms/seattle.c
> index 893cc17972..64cc1868c2 100644
> --- a/xen/arch/arm/platforms/seattle.c
> +++ b/xen/arch/arm/platforms/seattle.c
> @@ -33,12 +33,12 @@ static const char * const seattle_dt_compat[] __initconst =
>   */
>  static void seattle_system_reset(void)
>  {
> -    call_smc(PSCI_0_2_FN32_SYSTEM_RESET, 0, 0, 0);
> +    arm_smccc_smc(PSCI_0_2_FN32_SYSTEM_RESET, NULL);
>  }
>  
>  static void seattle_system_off(void)
>  {
> -    call_smc(PSCI_0_2_FN32_SYSTEM_OFF, 0, 0, 0);
> +    arm_smccc_smc(PSCI_0_2_FN32_SYSTEM_OFF, NULL);
>  }
>  
>  PLATFORM_START(seattle, "SEATTLE")
> diff --git a/xen/arch/arm/psci.c b/xen/arch/arm/psci.c
> index 941eec921b..4ae6504f3e 100644
> --- a/xen/arch/arm/psci.c
> +++ b/xen/arch/arm/psci.c
> @@ -42,42 +42,53 @@ uint32_t smccc_ver;
>  
>  static uint32_t psci_cpu_on_nr;
>  
> +#define PSCI_RET(res)   ((int32_t)(res).a0)
> +
>  int call_psci_cpu_on(int cpu)
>  {
> -    return call_smc(psci_cpu_on_nr, cpu_logical_map(cpu), __pa(init_secondary), 0);
> +    struct arm_smccc_res res;
> +
> +    arm_smccc_smc(psci_cpu_on_nr, cpu_logical_map(cpu), __pa(init_secondary),
> +                  &res);
> +
> +    return PSCI_RET(res.a0);
>  }
>  
>  void call_psci_cpu_off(void)
>  {
>      if ( psci_ver > PSCI_VERSION(0, 1) )
>      {
> -        int errno;
> +        struct arm_smccc_res res;
>  
>          /* If successfull the PSCI cpu_off call doesn't return */
> -        errno = call_smc(PSCI_0_2_FN32_CPU_OFF, 0, 0, 0);
> +        arm_smccc_smc(PSCI_0_2_FN32_CPU_OFF, &res);
>          panic("PSCI cpu off failed for CPU%d err=%d\n", smp_processor_id(),
> -              errno);
> +              PSCI_RET(res));
>      }
>  }
>  
>  void call_psci_system_off(void)
>  {
>      if ( psci_ver > PSCI_VERSION(0, 1) )
> -        call_smc(PSCI_0_2_FN32_SYSTEM_OFF, 0, 0, 0);
> +        arm_smccc_smc(PSCI_0_2_FN32_SYSTEM_OFF, NULL);
>  }
>  
>  void call_psci_system_reset(void)
>  {
>      if ( psci_ver > PSCI_VERSION(0, 1) )
> -        call_smc(PSCI_0_2_FN32_SYSTEM_RESET, 0, 0, 0);
> +        arm_smccc_smc(PSCI_0_2_FN32_SYSTEM_RESET, NULL);
>  }
>  
>  static int __init psci_features(uint32_t psci_func_id)
>  {
> +    struct arm_smccc_res res;
> +
>      if ( psci_ver < PSCI_VERSION(1, 0) )
>          return PSCI_NOT_SUPPORTED;
>  
> -    return call_smc(PSCI_1_0_FN32_PSCI_FEATURES, psci_func_id, 0, 0);
> +    arm_smccc_smc(PSCI_1_0_FN32_PSCI_FEATURES, psci_func_id, NULL);
> +
> +    return PSCI_RET(res);
>  }
>  
>  static int __init psci_is_smc_method(const struct dt_device_node *psci)
> @@ -112,11 +123,11 @@ static void __init psci_init_smccc(void)
>  
>      if ( psci_features(ARM_SMCCC_VERSION_FID) != PSCI_NOT_SUPPORTED )
>      {
> -        uint32_t ret;
> +        struct arm_smccc_res res;
>  
> -        ret = call_smc(ARM_SMCCC_VERSION_FID, 0, 0, 0);
> -        if ( ret != ARM_SMCCC_NOT_SUPPORTED )
> -            smccc_ver = ret;
> +        arm_smccc_smc(ARM_SMCCC_VERSION_FID, &res);
> +        if ( PSCI_RET(res) != ARM_SMCCC_NOT_SUPPORTED )
> +            smccc_ver = PSCI_RET(res);
>      }
>  
>      if ( smccc_ver >= SMCCC_VERSION(1, 1) )
> @@ -165,6 +176,7 @@ static int __init psci_init_0_2(void)
>          { /* sentinel */ },
>      };
>      int ret;
> +    struct arm_smccc_res res;
>  
>      if ( acpi_disabled )
>      {
> @@ -186,7 +198,8 @@ static int __init psci_init_0_2(void)
>          }
>      }
>  
> -    psci_ver = call_smc(PSCI_0_2_FN32_PSCI_VERSION, 0, 0, 0);
> +    arm_smccc_smc(PSCI_0_2_FN32_PSCI_VERSION, &res);
> +    psci_ver = PSCI_RET(res);
>  
>      /* For the moment, we only support PSCI 0.2 and PSCI 1.x */
>      if ( psci_ver != PSCI_VERSION(0, 2) && PSCI_VERSION_MAJOR(psci_ver) != 1 )
> diff --git a/xen/arch/arm/smc.S b/xen/arch/arm/smc.S
> deleted file mode 100644
> index b8f182272a..0000000000
> --- a/xen/arch/arm/smc.S
> +++ /dev/null
> @@ -1,21 +0,0 @@
> -/*
> - * xen/arch/arm/smc.S
> - *
> - * Wrapper for Secure Monitors Calls
> - *
> - * This program is free software; you can redistribute it and/or modify
> - * it under the terms of the GNU General Public License as published by
> - * the Free Software Foundation; either version 2 of the License, or
> - * (at your option) any later version.
> - *
> - * 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.
> - */
> -
> -#include <asm/macros.h>
> -
> -ENTRY(call_smc)
> -        smc   #0
> -        ret
> diff --git a/xen/include/asm-arm/processor.h b/xen/include/asm-arm/processor.h
> index 222a02dd99..8016cf306f 100644
> --- a/xen/include/asm-arm/processor.h
> +++ b/xen/include/asm-arm/processor.h
> @@ -812,9 +812,6 @@ void vcpu_regs_hyp_to_user(const struct vcpu *vcpu,
>  void vcpu_regs_user_to_hyp(struct vcpu *vcpu,
>                             const struct vcpu_guest_core_regs *regs);
>  
> -int call_smc(register_t function_id, register_t arg0, register_t arg1,
> -             register_t arg2);
> -
>  void do_trap_hyp_serror(struct cpu_user_regs *regs);
>  
>  void do_trap_guest_serror(struct cpu_user_regs *regs);
> -- 
> 2.11.0
>
Stefano Stabellini Oct. 1, 2018, 8:52 p.m. | #5
On Mon, 1 Oct 2018, Stefano Stabellini wrote:
> On Mon, 1 Oct 2018, Julien Grall wrote:
> > call_smc is a subset of arm_smccc_smc. Rather than having 2 methods to
> > do SMCCC call, replace all call to the former by the later.
> > 
> > Signed-off-by: Julien Grall <julien.grall@arm.com>
> 
> Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>
> 
> (you might want to make sure the double [[ is removed on commit.)

Hey Julien,

I was going to commit the series, but I am getting a build error:

psci.c: In function 'call_psci_cpu_on':
psci.c:45:40: error: request for member 'a0' in something not a structure or union
 #define PSCI_RET(res)   ((int32_t)(res).a0)
                                        ^
psci.c:54:12: note: in expansion of macro 'PSCI_RET'
     return PSCI_RET(res.a0);
            ^
psci.c:55:1: error: control reaches end of non-void function [-Werror=return-type]
 }



> > ---
> > 
> >     Changes in v3:
> >         - Use PSCI_RET where needed
> > ---
> >  xen/arch/arm/Makefile            |  1 -
> >  xen/arch/arm/platforms/exynos5.c |  3 ++-
> >  xen/arch/arm/platforms/seattle.c |  4 ++--
> >  xen/arch/arm/psci.c              | 37 +++++++++++++++++++++++++------------
> >  xen/arch/arm/smc.S               | 21 ---------------------
> >  xen/include/asm-arm/processor.h  |  3 ---
> >  6 files changed, 29 insertions(+), 40 deletions(-)
> >  delete mode 100644 xen/arch/arm/smc.S
> > 
> > diff --git a/xen/arch/arm/Makefile b/xen/arch/arm/Makefile
> > index b9b141dc84..37fa8268b3 100644
> > --- a/xen/arch/arm/Makefile
> > +++ b/xen/arch/arm/Makefile
> > @@ -39,7 +39,6 @@ obj-y += processor.o
> >  obj-y += psci.o
> >  obj-y += setup.o
> >  obj-y += shutdown.o
> > -obj-y += smc.o
> >  obj-y += smp.o
> >  obj-y += smpboot.o
> >  obj-y += sysctl.o
> > diff --git a/xen/arch/arm/platforms/exynos5.c b/xen/arch/arm/platforms/exynos5.c
> > index c15ecf80f5..e2c0b7b878 100644
> > --- a/xen/arch/arm/platforms/exynos5.c
> > +++ b/xen/arch/arm/platforms/exynos5.c
> > @@ -26,6 +26,7 @@
> >  #include <asm/platforms/exynos5.h>
> >  #include <asm/platform.h>
> >  #include <asm/io.h>
> > +#include <asm/smccc.h>
> >  
> >  static bool secure_firmware;
> >  
> > @@ -249,7 +250,7 @@ static int exynos5_cpu_up(int cpu)
> >      iounmap(power);
> >  
> >      if ( secure_firmware )
> > -        call_smc(SMC_CMD_CPU1BOOT, cpu, 0, 0);
> > +        arm_smccc_smc(SMC_CMD_CPU1BOOT, cpu, NULL);
> >  
> >      return cpu_up_send_sgi(cpu);
> >  }
> > diff --git a/xen/arch/arm/platforms/seattle.c b/xen/arch/arm/platforms/seattle.c
> > index 893cc17972..64cc1868c2 100644
> > --- a/xen/arch/arm/platforms/seattle.c
> > +++ b/xen/arch/arm/platforms/seattle.c
> > @@ -33,12 +33,12 @@ static const char * const seattle_dt_compat[] __initconst =
> >   */
> >  static void seattle_system_reset(void)
> >  {
> > -    call_smc(PSCI_0_2_FN32_SYSTEM_RESET, 0, 0, 0);
> > +    arm_smccc_smc(PSCI_0_2_FN32_SYSTEM_RESET, NULL);
> >  }
> >  
> >  static void seattle_system_off(void)
> >  {
> > -    call_smc(PSCI_0_2_FN32_SYSTEM_OFF, 0, 0, 0);
> > +    arm_smccc_smc(PSCI_0_2_FN32_SYSTEM_OFF, NULL);
> >  }
> >  
> >  PLATFORM_START(seattle, "SEATTLE")
> > diff --git a/xen/arch/arm/psci.c b/xen/arch/arm/psci.c
> > index 941eec921b..4ae6504f3e 100644
> > --- a/xen/arch/arm/psci.c
> > +++ b/xen/arch/arm/psci.c
> > @@ -42,42 +42,53 @@ uint32_t smccc_ver;
> >  
> >  static uint32_t psci_cpu_on_nr;
> >  
> > +#define PSCI_RET(res)   ((int32_t)(res).a0)
> > +
> >  int call_psci_cpu_on(int cpu)
> >  {
> > -    return call_smc(psci_cpu_on_nr, cpu_logical_map(cpu), __pa(init_secondary), 0);
> > +    struct arm_smccc_res res;
> > +
> > +    arm_smccc_smc(psci_cpu_on_nr, cpu_logical_map(cpu), __pa(init_secondary),
> > +                  &res);
> > +
> > +    return PSCI_RET(res.a0);
> >  }
> >  
> >  void call_psci_cpu_off(void)
> >  {
> >      if ( psci_ver > PSCI_VERSION(0, 1) )
> >      {
> > -        int errno;
> > +        struct arm_smccc_res res;
> >  
> >          /* If successfull the PSCI cpu_off call doesn't return */
> > -        errno = call_smc(PSCI_0_2_FN32_CPU_OFF, 0, 0, 0);
> > +        arm_smccc_smc(PSCI_0_2_FN32_CPU_OFF, &res);
> >          panic("PSCI cpu off failed for CPU%d err=%d\n", smp_processor_id(),
> > -              errno);
> > +              PSCI_RET(res));
> >      }
> >  }
> >  
> >  void call_psci_system_off(void)
> >  {
> >      if ( psci_ver > PSCI_VERSION(0, 1) )
> > -        call_smc(PSCI_0_2_FN32_SYSTEM_OFF, 0, 0, 0);
> > +        arm_smccc_smc(PSCI_0_2_FN32_SYSTEM_OFF, NULL);
> >  }
> >  
> >  void call_psci_system_reset(void)
> >  {
> >      if ( psci_ver > PSCI_VERSION(0, 1) )
> > -        call_smc(PSCI_0_2_FN32_SYSTEM_RESET, 0, 0, 0);
> > +        arm_smccc_smc(PSCI_0_2_FN32_SYSTEM_RESET, NULL);
> >  }
> >  
> >  static int __init psci_features(uint32_t psci_func_id)
> >  {
> > +    struct arm_smccc_res res;
> > +
> >      if ( psci_ver < PSCI_VERSION(1, 0) )
> >          return PSCI_NOT_SUPPORTED;
> >  
> > -    return call_smc(PSCI_1_0_FN32_PSCI_FEATURES, psci_func_id, 0, 0);
> > +    arm_smccc_smc(PSCI_1_0_FN32_PSCI_FEATURES, psci_func_id, NULL);
> > +
> > +    return PSCI_RET(res);
> >  }
> >  
> >  static int __init psci_is_smc_method(const struct dt_device_node *psci)
> > @@ -112,11 +123,11 @@ static void __init psci_init_smccc(void)
> >  
> >      if ( psci_features(ARM_SMCCC_VERSION_FID) != PSCI_NOT_SUPPORTED )
> >      {
> > -        uint32_t ret;
> > +        struct arm_smccc_res res;
> >  
> > -        ret = call_smc(ARM_SMCCC_VERSION_FID, 0, 0, 0);
> > -        if ( ret != ARM_SMCCC_NOT_SUPPORTED )
> > -            smccc_ver = ret;
> > +        arm_smccc_smc(ARM_SMCCC_VERSION_FID, &res);
> > +        if ( PSCI_RET(res) != ARM_SMCCC_NOT_SUPPORTED )
> > +            smccc_ver = PSCI_RET(res);
> >      }
> >  
> >      if ( smccc_ver >= SMCCC_VERSION(1, 1) )
> > @@ -165,6 +176,7 @@ static int __init psci_init_0_2(void)
> >          { /* sentinel */ },
> >      };
> >      int ret;
> > +    struct arm_smccc_res res;
> >  
> >      if ( acpi_disabled )
> >      {
> > @@ -186,7 +198,8 @@ static int __init psci_init_0_2(void)
> >          }
> >      }
> >  
> > -    psci_ver = call_smc(PSCI_0_2_FN32_PSCI_VERSION, 0, 0, 0);
> > +    arm_smccc_smc(PSCI_0_2_FN32_PSCI_VERSION, &res);
> > +    psci_ver = PSCI_RET(res);
> >  
> >      /* For the moment, we only support PSCI 0.2 and PSCI 1.x */
> >      if ( psci_ver != PSCI_VERSION(0, 2) && PSCI_VERSION_MAJOR(psci_ver) != 1 )
> > diff --git a/xen/arch/arm/smc.S b/xen/arch/arm/smc.S
> > deleted file mode 100644
> > index b8f182272a..0000000000
> > --- a/xen/arch/arm/smc.S
> > +++ /dev/null
> > @@ -1,21 +0,0 @@
> > -/*
> > - * xen/arch/arm/smc.S
> > - *
> > - * Wrapper for Secure Monitors Calls
> > - *
> > - * This program is free software; you can redistribute it and/or modify
> > - * it under the terms of the GNU General Public License as published by
> > - * the Free Software Foundation; either version 2 of the License, or
> > - * (at your option) any later version.
> > - *
> > - * 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.
> > - */
> > -
> > -#include <asm/macros.h>
> > -
> > -ENTRY(call_smc)
> > -        smc   #0
> > -        ret
> > diff --git a/xen/include/asm-arm/processor.h b/xen/include/asm-arm/processor.h
> > index 222a02dd99..8016cf306f 100644
> > --- a/xen/include/asm-arm/processor.h
> > +++ b/xen/include/asm-arm/processor.h
> > @@ -812,9 +812,6 @@ void vcpu_regs_hyp_to_user(const struct vcpu *vcpu,
> >  void vcpu_regs_user_to_hyp(struct vcpu *vcpu,
> >                             const struct vcpu_guest_core_regs *regs);
> >  
> > -int call_smc(register_t function_id, register_t arg0, register_t arg1,
> > -             register_t arg2);
> > -
> >  void do_trap_hyp_serror(struct cpu_user_regs *regs);
> >  
> >  void do_trap_guest_serror(struct cpu_user_regs *regs);
> > -- 
> > 2.11.0
> > 
>
Julien Grall Oct. 1, 2018, 8:57 p.m. | #6
Hi Stefano,

On 10/01/2018 09:52 PM, Stefano Stabellini wrote:
> On Mon, 1 Oct 2018, Stefano Stabellini wrote:
>> On Mon, 1 Oct 2018, Julien Grall wrote:
>>> call_smc is a subset of arm_smccc_smc. Rather than having 2 methods to
>>> do SMCCC call, replace all call to the former by the later.
>>>
>>> Signed-off-by: Julien Grall <julien.grall@arm.com>
>>
>> Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>
>>
>> (you might want to make sure the double [[ is removed on commit.)
> 
> Hey Julien,
> 
> I was going to commit the series, but I am getting a build error:
> 
> psci.c: In function 'call_psci_cpu_on':
> psci.c:45:40: error: request for member 'a0' in something not a structure or union
>   #define PSCI_RET(res)   ((int32_t)(res).a0)
>                                          ^
> psci.c:54:12: note: in expansion of macro 'PSCI_RET'
>       return PSCI_RET(res.a0);
>              ^
> psci.c:55:1: error: control reaches end of non-void function [-Werror=return-type]
>   }

I already mentioned this error in reply to the patch [1] and suggested 
it could be fixed on commit...

Cheers,

[1] <9e0160ad-853c-6efa-1a04-15f801ef06da@arm.com>

Patch

diff --git a/xen/arch/arm/Makefile b/xen/arch/arm/Makefile
index b9b141dc84..37fa8268b3 100644
--- a/xen/arch/arm/Makefile
+++ b/xen/arch/arm/Makefile
@@ -39,7 +39,6 @@  obj-y += processor.o
 obj-y += psci.o
 obj-y += setup.o
 obj-y += shutdown.o
-obj-y += smc.o
 obj-y += smp.o
 obj-y += smpboot.o
 obj-y += sysctl.o
diff --git a/xen/arch/arm/platforms/exynos5.c b/xen/arch/arm/platforms/exynos5.c
index c15ecf80f5..e2c0b7b878 100644
--- a/xen/arch/arm/platforms/exynos5.c
+++ b/xen/arch/arm/platforms/exynos5.c
@@ -26,6 +26,7 @@ 
 #include <asm/platforms/exynos5.h>
 #include <asm/platform.h>
 #include <asm/io.h>
+#include <asm/smccc.h>
 
 static bool secure_firmware;
 
@@ -249,7 +250,7 @@  static int exynos5_cpu_up(int cpu)
     iounmap(power);
 
     if ( secure_firmware )
-        call_smc(SMC_CMD_CPU1BOOT, cpu, 0, 0);
+        arm_smccc_smc(SMC_CMD_CPU1BOOT, cpu, NULL);
 
     return cpu_up_send_sgi(cpu);
 }
diff --git a/xen/arch/arm/platforms/seattle.c b/xen/arch/arm/platforms/seattle.c
index 893cc17972..64cc1868c2 100644
--- a/xen/arch/arm/platforms/seattle.c
+++ b/xen/arch/arm/platforms/seattle.c
@@ -33,12 +33,12 @@  static const char * const seattle_dt_compat[] __initconst =
  */
 static void seattle_system_reset(void)
 {
-    call_smc(PSCI_0_2_FN32_SYSTEM_RESET, 0, 0, 0);
+    arm_smccc_smc(PSCI_0_2_FN32_SYSTEM_RESET, NULL);
 }
 
 static void seattle_system_off(void)
 {
-    call_smc(PSCI_0_2_FN32_SYSTEM_OFF, 0, 0, 0);
+    arm_smccc_smc(PSCI_0_2_FN32_SYSTEM_OFF, NULL);
 }
 
 PLATFORM_START(seattle, "SEATTLE")
diff --git a/xen/arch/arm/psci.c b/xen/arch/arm/psci.c
index 941eec921b..4ae6504f3e 100644
--- a/xen/arch/arm/psci.c
+++ b/xen/arch/arm/psci.c
@@ -42,42 +42,53 @@  uint32_t smccc_ver;
 
 static uint32_t psci_cpu_on_nr;
 
+#define PSCI_RET(res)   ((int32_t)(res).a0)
+
 int call_psci_cpu_on(int cpu)
 {
-    return call_smc(psci_cpu_on_nr, cpu_logical_map(cpu), __pa(init_secondary), 0);
+    struct arm_smccc_res res;
+
+    arm_smccc_smc(psci_cpu_on_nr, cpu_logical_map(cpu), __pa(init_secondary),
+                  &res);
+
+    return PSCI_RET(res.a0);
 }
 
 void call_psci_cpu_off(void)
 {
     if ( psci_ver > PSCI_VERSION(0, 1) )
     {
-        int errno;
+        struct arm_smccc_res res;
 
         /* If successfull the PSCI cpu_off call doesn't return */
-        errno = call_smc(PSCI_0_2_FN32_CPU_OFF, 0, 0, 0);
+        arm_smccc_smc(PSCI_0_2_FN32_CPU_OFF, &res);
         panic("PSCI cpu off failed for CPU%d err=%d\n", smp_processor_id(),
-              errno);
+              PSCI_RET(res));
     }
 }
 
 void call_psci_system_off(void)
 {
     if ( psci_ver > PSCI_VERSION(0, 1) )
-        call_smc(PSCI_0_2_FN32_SYSTEM_OFF, 0, 0, 0);
+        arm_smccc_smc(PSCI_0_2_FN32_SYSTEM_OFF, NULL);
 }
 
 void call_psci_system_reset(void)
 {
     if ( psci_ver > PSCI_VERSION(0, 1) )
-        call_smc(PSCI_0_2_FN32_SYSTEM_RESET, 0, 0, 0);
+        arm_smccc_smc(PSCI_0_2_FN32_SYSTEM_RESET, NULL);
 }
 
 static int __init psci_features(uint32_t psci_func_id)
 {
+    struct arm_smccc_res res;
+
     if ( psci_ver < PSCI_VERSION(1, 0) )
         return PSCI_NOT_SUPPORTED;
 
-    return call_smc(PSCI_1_0_FN32_PSCI_FEATURES, psci_func_id, 0, 0);
+    arm_smccc_smc(PSCI_1_0_FN32_PSCI_FEATURES, psci_func_id, NULL);
+
+    return PSCI_RET(res);
 }
 
 static int __init psci_is_smc_method(const struct dt_device_node *psci)
@@ -112,11 +123,11 @@  static void __init psci_init_smccc(void)
 
     if ( psci_features(ARM_SMCCC_VERSION_FID) != PSCI_NOT_SUPPORTED )
     {
-        uint32_t ret;
+        struct arm_smccc_res res;
 
-        ret = call_smc(ARM_SMCCC_VERSION_FID, 0, 0, 0);
-        if ( ret != ARM_SMCCC_NOT_SUPPORTED )
-            smccc_ver = ret;
+        arm_smccc_smc(ARM_SMCCC_VERSION_FID, &res);
+        if ( PSCI_RET(res) != ARM_SMCCC_NOT_SUPPORTED )
+            smccc_ver = PSCI_RET(res);
     }
 
     if ( smccc_ver >= SMCCC_VERSION(1, 1) )
@@ -165,6 +176,7 @@  static int __init psci_init_0_2(void)
         { /* sentinel */ },
     };
     int ret;
+    struct arm_smccc_res res;
 
     if ( acpi_disabled )
     {
@@ -186,7 +198,8 @@  static int __init psci_init_0_2(void)
         }
     }
 
-    psci_ver = call_smc(PSCI_0_2_FN32_PSCI_VERSION, 0, 0, 0);
+    arm_smccc_smc(PSCI_0_2_FN32_PSCI_VERSION, &res);
+    psci_ver = PSCI_RET(res);
 
     /* For the moment, we only support PSCI 0.2 and PSCI 1.x */
     if ( psci_ver != PSCI_VERSION(0, 2) && PSCI_VERSION_MAJOR(psci_ver) != 1 )
diff --git a/xen/arch/arm/smc.S b/xen/arch/arm/smc.S
deleted file mode 100644
index b8f182272a..0000000000
--- a/xen/arch/arm/smc.S
+++ /dev/null
@@ -1,21 +0,0 @@ 
-/*
- * xen/arch/arm/smc.S
- *
- * Wrapper for Secure Monitors Calls
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; either version 2 of the License, or
- * (at your option) any later version.
- *
- * 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.
- */
-
-#include <asm/macros.h>
-
-ENTRY(call_smc)
-        smc   #0
-        ret
diff --git a/xen/include/asm-arm/processor.h b/xen/include/asm-arm/processor.h
index 222a02dd99..8016cf306f 100644
--- a/xen/include/asm-arm/processor.h
+++ b/xen/include/asm-arm/processor.h
@@ -812,9 +812,6 @@  void vcpu_regs_hyp_to_user(const struct vcpu *vcpu,
 void vcpu_regs_user_to_hyp(struct vcpu *vcpu,
                            const struct vcpu_guest_core_regs *regs);
 
-int call_smc(register_t function_id, register_t arg0, register_t arg1,
-             register_t arg2);
-
 void do_trap_hyp_serror(struct cpu_user_regs *regs);
 
 void do_trap_guest_serror(struct cpu_user_regs *regs);