[PATCH 07/12] arm64: psci: kill psci_power_state

[lorenzo.pieralisi@arm.com (Lorenzo Pieralisi)]

On Fri, May 08, 2015 at 12:36:39PM +0100, Mark Rutland wrote:
> A PSCI 1.0 implementation may choose to use the new extended StateID
> format, the presence of which may be queried via the PSCI_FEATURES call.
> The layout of this new StateID format is incompatible with the existing
> format, and so to handle both we must abstract attempts to parse the
> fields.
> 
> In preparation for PSCI 1.0 support, this patch introduces
> psci_power_state_loses_context and psci_power_state_is_valid functions
> to query information from a PSCI power state, which is no longer
> decomposed (and hence the pack/unpack functions are removed). As it is
> no longer decomposed, it is now passed round as an opaque u32 token.
> 
> Signed-off-by: Mark Rutland <mark.rutland@arm.com>
> Cc: Catalin Marinas <catalin.marinas@arm.com>
> Cc: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
> Cc: Will Deacon <will.deacon@arm.com>
> ---
>  arch/arm64/kernel/psci.c | 89 ++++++++++++++++++++----------------------------
>  1 file changed, 37 insertions(+), 52 deletions(-)

Acked-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>

> diff --git a/arch/arm64/kernel/psci.c b/arch/arm64/kernel/psci.c
> index 25e2610..185174e 100644
> --- a/arch/arm64/kernel/psci.c
> +++ b/arch/arm64/kernel/psci.c
> @@ -37,11 +37,19 @@
>  #define PSCI_POWER_STATE_TYPE_STANDBY		0
>  #define PSCI_POWER_STATE_TYPE_POWER_DOWN	1
>  
> -struct psci_power_state {
> -	u16	id;
> -	u8	type;
> -	u8	affinity_level;
> -};
> +static bool psci_power_state_loses_context(u32 state)
> +{
> +	return !!(state & PSCI_0_2_POWER_STATE_TYPE_MASK);
> +}
> +
> +static bool psci_power_state_is_valid(u32 state)
> +{
> +	const u32 valid_mask = PSCI_0_2_POWER_STATE_ID_MASK |
> +			       PSCI_0_2_POWER_STATE_TYPE_MASK |
> +			       PSCI_0_2_POWER_STATE_AFFL_MASK;
> +
> +	return !(state & ~valid_mask);
> +}
>  
>  /*
>   * The CPU any Trusted OS is resident on. The trusted OS may reject CPU_OFF
> @@ -57,9 +65,8 @@ static bool psci_tos_resident_on(int cpu)
>  }
>  
>  struct psci_operations {
> -	int (*cpu_suspend)(struct psci_power_state state,
> -			   unsigned long entry_point);
> -	int (*cpu_off)(struct psci_power_state state);
> +	int (*cpu_suspend)(u32 state, unsigned long entry_point);
> +	int (*cpu_off)(u32 state);
>  	int (*cpu_on)(unsigned long cpuid, unsigned long entry_point);
>  	int (*migrate)(unsigned long cpuid);
>  	int (*affinity_info)(unsigned long target_affinity,
> @@ -84,7 +91,7 @@ enum psci_function {
>  	PSCI_FN_MAX,
>  };
>  
> -static DEFINE_PER_CPU_READ_MOSTLY(struct psci_power_state *, psci_power_state);
> +static DEFINE_PER_CPU_READ_MOSTLY(u32 *, psci_power_state);
>  
>  static u32 psci_function_id[PSCI_FN_MAX];
>  
> @@ -104,53 +111,28 @@ static int psci_to_linux_errno(int errno)
>  	return -EINVAL;
>  }
>  
> -static u32 psci_power_state_pack(struct psci_power_state state)
> -{
> -	return ((state.id << PSCI_0_2_POWER_STATE_ID_SHIFT)
> -			& PSCI_0_2_POWER_STATE_ID_MASK) |
> -		((state.type << PSCI_0_2_POWER_STATE_TYPE_SHIFT)
> -		 & PSCI_0_2_POWER_STATE_TYPE_MASK) |
> -		((state.affinity_level << PSCI_0_2_POWER_STATE_AFFL_SHIFT)
> -		 & PSCI_0_2_POWER_STATE_AFFL_MASK);
> -}
> -
> -static void psci_power_state_unpack(u32 power_state,
> -				    struct psci_power_state *state)
> -{
> -	state->id = (power_state & PSCI_0_2_POWER_STATE_ID_MASK) >>
> -			PSCI_0_2_POWER_STATE_ID_SHIFT;
> -	state->type = (power_state & PSCI_0_2_POWER_STATE_TYPE_MASK) >>
> -			PSCI_0_2_POWER_STATE_TYPE_SHIFT;
> -	state->affinity_level =
> -			(power_state & PSCI_0_2_POWER_STATE_AFFL_MASK) >>
> -			PSCI_0_2_POWER_STATE_AFFL_SHIFT;
> -}
> -
>  static u32 psci_get_version(void)
>  {
>  	return invoke_psci_fn(PSCI_0_2_FN_PSCI_VERSION, 0, 0, 0);
>  }
>  
> -static int psci_cpu_suspend(struct psci_power_state state,
> -			    unsigned long entry_point)
> +static int psci_cpu_suspend(u32 state, unsigned long entry_point)
>  {
>  	int err;
> -	u32 fn, power_state;
> +	u32 fn;
>  
>  	fn = psci_function_id[PSCI_FN_CPU_SUSPEND];
> -	power_state = psci_power_state_pack(state);
> -	err = invoke_psci_fn(fn, power_state, entry_point, 0);
> +	err = invoke_psci_fn(fn, state, entry_point, 0);
>  	return psci_to_linux_errno(err);
>  }
>  
> -static int psci_cpu_off(struct psci_power_state state)
> +static int psci_cpu_off(u32 state)
>  {
>  	int err;
> -	u32 fn, power_state;
> +	u32 fn;
>  
>  	fn = psci_function_id[PSCI_FN_CPU_OFF];
> -	power_state = psci_power_state_pack(state);
> -	err = invoke_psci_fn(fn, power_state, 0, 0);
> +	err = invoke_psci_fn(fn, state, 0, 0);
>  	return psci_to_linux_errno(err);
>  }
>  
> @@ -195,7 +177,7 @@ static int __maybe_unused cpu_psci_cpu_init_idle(struct device_node *cpu_node,
>  						 unsigned int cpu)
>  {
>  	int i, ret, count = 0;
> -	struct psci_power_state *psci_states;
> +	u32 *psci_states;
>  	struct device_node *state_node;
>  
>  	/*
> @@ -220,13 +202,13 @@ static int __maybe_unused cpu_psci_cpu_init_idle(struct device_node *cpu_node,
>  		return -ENOMEM;
>  
>  	for (i = 0; i < count; i++) {
> -		u32 psci_power_state;
> +		u32 state;
>  
>  		state_node = of_parse_phandle(cpu_node, "cpu-idle-states", i);
>  
>  		ret = of_property_read_u32(state_node,
>  					   "arm,psci-suspend-param",
> -					   &psci_power_state);
> +					   &state);
>  		if (ret) {
>  			pr_warn(" * %s missing arm,psci-suspend-param property\n",
>  				state_node->full_name);
> @@ -235,9 +217,13 @@ static int __maybe_unused cpu_psci_cpu_init_idle(struct device_node *cpu_node,
>  		}
>  
>  		of_node_put(state_node);
> -		pr_debug("psci-power-state %#x index %d\n", psci_power_state,
> -							    i);
> -		psci_power_state_unpack(psci_power_state, &psci_states[i]);
> +		pr_debug("psci-power-state %#x index %d\n", state, i);
> +		if (!psci_power_state_is_valid(state)) {
> +			pr_warn("Invalid PSCI power state %#x\n", state);
> +			ret = -EINVAL;
> +			goto free_mem;
> +		}
> +		psci_states[i] = state;
>  	}
>  	/* Idle states parsed correctly, initialize per-cpu pointer */
>  	per_cpu(psci_power_state, cpu) = psci_states;
> @@ -520,9 +506,8 @@ static void cpu_psci_cpu_die(unsigned int cpu)
>  	 * There are no known implementations of PSCI actually using the
>  	 * power state field, pass a sensible default for now.
>  	 */
> -	struct psci_power_state state = {
> -		.type = PSCI_POWER_STATE_TYPE_POWER_DOWN,
> -	};
> +	u32 state = PSCI_POWER_STATE_TYPE_POWER_DOWN <<
> +		    PSCI_0_2_POWER_STATE_TYPE_SHIFT;
>  
>  	ret = psci_ops.cpu_off(state);
>  
> @@ -561,7 +546,7 @@ static int cpu_psci_cpu_kill(unsigned int cpu)
>  
>  static int psci_suspend_finisher(unsigned long index)
>  {
> -	struct psci_power_state *state = __this_cpu_read(psci_power_state);
> +	u32 *state = __this_cpu_read(psci_power_state);
>  
>  	return psci_ops.cpu_suspend(state[index - 1],
>  				    virt_to_phys(cpu_resume));
> @@ -570,7 +555,7 @@ static int psci_suspend_finisher(unsigned long index)
>  static int __maybe_unused cpu_psci_cpu_suspend(unsigned long index)
>  {
>  	int ret;
> -	struct psci_power_state *state = __this_cpu_read(psci_power_state);
> +	u32 *state = __this_cpu_read(psci_power_state);
>  	/*
>  	 * idle state index 0 corresponds to wfi, should never be called
>  	 * from the cpu_suspend operations
> @@ -578,7 +563,7 @@ static int __maybe_unused cpu_psci_cpu_suspend(unsigned long index)
>  	if (WARN_ON_ONCE(!index))
>  		return -EINVAL;
>  
> -	if (state[index - 1].type == PSCI_POWER_STATE_TYPE_STANDBY)
> +	if (!psci_power_state_loses_context(state[index - 1]))
>  		ret = psci_ops.cpu_suspend(state[index - 1], 0);
>  	else
>  		ret = __cpu_suspend(index, psci_suspend_finisher);
> -- 
> 1.9.1
>