Re: [PATCH 5/5] ARM64: kernel: acpi: honour acpi=force command line parameter

[Hanjun Guo <guohanjun@huawei.com>]

On 2015/3/25 1:58, Lorenzo Pieralisi wrote:
> If acpi=force is passed on the command line, it forces ACPI to be
> the only available boot method, hence it must be left enabled even
> if the initialization and sanity checks on ACPI tables fails.
>
> This patch refactors ACPI initialization to prevent disabling ACPI
> if acpi=force is passed on the command line.
>
> Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
> Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
> Cc: Hanjun Guo <hanjun.guo@linaro.org>
> Cc: Catalin Marinas <catalin.marinas@arm.com>
> ---

Although it will introduce some useless table parsing for some
bad ACPI tables, it still obey the policy for acpi=force, and it makes
param_acpi_force much self-contained, so

Acked-by: Hanjun Guo <hanjun.guo@linaro.org>

Thanks
Hanjun


>  arch/arm64/include/asm/acpi.h | 3 ---
>  arch/arm64/kernel/acpi.c      | 6 ++++--
>  arch/arm64/kernel/setup.c     | 2 +-
>  3 files changed, 5 insertions(+), 6 deletions(-)
>
> diff --git a/arch/arm64/include/asm/acpi.h b/arch/arm64/include/asm/acpi.h
> index e1a8965..59c05d8 100644
> --- a/arch/arm64/include/asm/acpi.h
> +++ b/arch/arm64/include/asm/acpi.h
> @@ -38,7 +38,6 @@ typedef u64 phys_cpuid_t;
>  extern int acpi_disabled;
>  extern int acpi_noirq;
>  extern int acpi_pci_disabled;
> -extern bool param_acpi_force;
>  
>  /* 1 to indicate PSCI 0.2+ is implemented */
>  static inline bool acpi_psci_present(void)
> @@ -92,8 +91,6 @@ void __init acpi_init_cpus(void);
>  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) { }
> -
> -#define param_acpi_force false
>  #endif /* CONFIG_ACPI */
>  
>  #endif /*_ASM_ACPI_H*/
> diff --git a/arch/arm64/kernel/acpi.c b/arch/arm64/kernel/acpi.c
> index 542f045..789994a 100644
> --- a/arch/arm64/kernel/acpi.c
> +++ b/arch/arm64/kernel/acpi.c
> @@ -43,7 +43,7 @@ static int enabled_cpus;
>  static bool bootcpu_valid  __initdata;
>  
>  static bool param_acpi_off __initdata;
> -bool param_acpi_force __initdata;
> +static bool param_acpi_force __initdata;
>  
>  static int __init parse_acpi(char *arg)
>  {
> @@ -324,8 +324,10 @@ out:
>  	 * If ACPI tables are initialized and FADT sanity checks passed,
>  	 * leave ACPI enabled and carry on booting; otherwise disable ACPI
>  	 * on initialization error.
> +	 * If acpi=force was passed on the command line it forces ACPI
> +	 * to be enabled even if its initialization failed.
>  	 */
> -	if (err)
> +	if (err && !param_acpi_force)
>  		disable_acpi();
>  }
>  
> diff --git a/arch/arm64/kernel/setup.c b/arch/arm64/kernel/setup.c
> index d60b1ad..b278311 100644
> --- a/arch/arm64/kernel/setup.c
> +++ b/arch/arm64/kernel/setup.c
> @@ -390,7 +390,7 @@ void __init setup_arch(char **cmdline_p)
>  
>  	early_ioremap_reset();
>  
> -	if (acpi_disabled  && !param_acpi_force) {
> +	if (acpi_disabled) {
>  		unflatten_device_tree();
>  		psci_dt_init();
>  		cpu_read_bootcpu_ops();