Subject: [PATCHv3 08/12] arm64: psci: remove ACPI coupling

From: [email-masked] (Al Stone)
Date: Tue, 26 May 2015 14:18:30 -0600

On 05/26/2015 07:52 AM, Mark Rutland wrote:
> The 32-bit ARM port doesn't have ACPI headers, and conditionally
> including them is going to look horrendous. In preparation for sharing
> the PSCI invocation code with 32-bit, move the acpi_psci_* function
> declarations and definitions such that the PSCI client code need not
> include ACPI headers.
> 
> While it would seem like we could simply hide the ACPI includes in
> psci.h, the ACPI headers have hilarious circular dependencies which make
> this infeasible without reorganising most of ACPICA. So rather than
> doing that, move the acpi_psci_* prototypes into psci.h.

I really doubt "hilarious" was the first word that came to mind in trying
to figure out those dependencies :-).  It was not the first word I used,
I assure you.

Patch LGTM: Reviewed-by: Al Stone <[email-masked]>

> The psci_acpi_init function is made dependent on CONFIG_ACPI (with a
> stub implementation in asm/psci.h) such that it need not be built for
> 32-bit ARM or kernels without ACPI support. The currently missing __init
> annotations are added to the prototypes in the header.
> 
> Signed-off-by: Mark Rutland <[email-masked]>
> Acked-by: Catalin Marinas <[email-masked]>
> Acked-by: Hanjun Guo <[email-masked]>
> Reviewed-by: Ashwin Chaugule <[email-masked]>
> Cc: Al Stone <[email-masked]>
> Cc: Lorenzo Pieralisi <[email-masked]>
> Cc: Will Deacon <[email-masked]>
> ---
>  arch/arm64/include/asm/acpi.h | 15 +--------------
>  arch/arm64/include/asm/psci.h | 12 ++++++++++--
>  arch/arm64/kernel/acpi.c      | 11 +++++++++++
>  arch/arm64/kernel/psci.c      |  4 ++--
>  4 files changed, 24 insertions(+), 18 deletions(-)
> 
> diff --git a/arch/arm64/include/asm/acpi.h b/arch/arm64/include/asm/acpi.h
> index 1240b86..39248d3 100644
> --- a/arch/arm64/include/asm/acpi.h
> +++ b/arch/arm64/include/asm/acpi.h
> @@ -16,6 +16,7 @@
>  #include <linux/irqchip/arm-gic-acpi.h>
>  
>  #include <asm/cputype.h>
> +#include <asm/psci.h>
>  #include <asm/smp_plat.h>
>  
>  /* Basic configuration for ACPI */
> @@ -39,18 +40,6 @@ extern int acpi_disabled;
>  extern int acpi_noirq;
>  extern int acpi_pci_disabled;
>  
> -/* 1 to indicate PSCI 0.2+ is implemented */
> -static inline bool acpi_psci_present(void)
> -{
> -	return acpi_gbl_FADT.arm_boot_flags & ACPI_FADT_PSCI_COMPLIANT;
> -}
> -
> -/* 1 to indicate HVC must be used instead of SMC as the PSCI conduit */
> -static inline bool acpi_psci_use_hvc(void)
> -{
> -	return acpi_gbl_FADT.arm_boot_flags & ACPI_FADT_PSCI_USE_HVC;
> -}
> -
>  static inline void disable_acpi(void)
>  {
>  	acpi_disabled = 1;
> @@ -88,8 +77,6 @@ static inline void arch_fix_phys_package_id(int num, u32 slot) { }
>  void __init acpi_init_cpus(void);
>  
>  #else
> -static inline bool acpi_psci_present(void) { return false; }
> -static inline bool acpi_psci_use_hvc(void) { return false; }
>  static inline void acpi_init_cpus(void) { }
>  #endif /* CONFIG_ACPI */
>  
> diff --git a/arch/arm64/include/asm/psci.h b/arch/arm64/include/asm/psci.h
> index 2454bc5..49d7e1a 100644
> --- a/arch/arm64/include/asm/psci.h
> +++ b/arch/arm64/include/asm/psci.h
> @@ -14,7 +14,15 @@
>  #ifndef __ASM_PSCI_H
>  #define __ASM_PSCI_H
>  
> -int psci_dt_init(void);
> -int psci_acpi_init(void);
> +int __init psci_dt_init(void);
> +
> +#ifdef CONFIG_ACPI
> +int __init psci_acpi_init(void);
> +bool __init acpi_psci_present(void);
> +bool __init acpi_psci_use_hvc(void);
> +#else
> +static inline int psci_acpi_init(void) { return 0; }
> +static inline bool acpi_psci_present(void) { return false; }
> +#endif
>  
>  #endif /* __ASM_PSCI_H */
> diff --git a/arch/arm64/kernel/acpi.c b/arch/arm64/kernel/acpi.c
> index 732f57b..19de753 100644
> --- a/arch/arm64/kernel/acpi.c
> +++ b/arch/arm64/kernel/acpi.c
> @@ -89,6 +89,17 @@ void __init __acpi_unmap_table(char *map, unsigned long size)
>  	early_memunmap(map, size);
>  }
>  
> +bool __init acpi_psci_present(void)
> +{
> +	return acpi_gbl_FADT.arm_boot_flags & ACPI_FADT_PSCI_COMPLIANT;
> +}
> +
> +/* Whether HVC must be used instead of SMC as the PSCI conduit */
> +bool __init acpi_psci_use_hvc(void)
> +{
> +	return acpi_gbl_FADT.arm_boot_flags & ACPI_FADT_PSCI_USE_HVC;
> +}
> +
>  /*
>   * acpi_fadt_sanity_check() - Check FADT presence and carry out sanity
>   *			      checks on it
> diff --git a/arch/arm64/kernel/psci.c b/arch/arm64/kernel/psci.c
> index 0e2a440..cba05d9 100644
> --- a/arch/arm64/kernel/psci.c
> +++ b/arch/arm64/kernel/psci.c
> @@ -15,7 +15,6 @@
>  
>  #define pr_fmt(fmt) "psci: " fmt
>  
> -#include <linux/acpi.h>
>  #include <linux/init.h>
>  #include <linux/of.h>
>  #include <linux/smp.h>
> @@ -25,7 +24,6 @@
>  #include <linux/slab.h>
>  #include <uapi/linux/psci.h>
>  
> -#include <asm/acpi.h>
>  #include <asm/compiler.h>
>  #include <asm/cputype.h>
>  #include <asm/cpu_ops.h>
> @@ -446,6 +444,7 @@ int __init psci_dt_init(void)
>  	return init_fn(np);
>  }
>  
> +#ifdef CONFIG_ACPI
>  /*
>   * We use PSCI 0.2+ when ACPI is deployed on ARM64 and it's
>   * explicitly clarified in SBBR
> @@ -466,6 +465,7 @@ int __init psci_acpi_init(void)
>  
>  	return psci_probe();
>  }
> +#endif
>  
>  #ifdef CONFIG_SMP
>  
> 

-- 
ciao,
al
-----------------------------------
Al Stone
Software Engineer
Linaro Enterprise Group
al.stone at linaro.org
-----------------------------------