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From: Mark Rutland <mark.rutland@arm.com>
To: David Brazdil <dbrazdil@google.com>
Cc: kvmarm@lists.cs.columbia.edu, Jonathan Corbet <corbet@lwn.net>,
	Catalin Marinas <catalin.marinas@arm.com>,
	Will Deacon <will@kernel.org>, Marc Zyngier <maz@kernel.org>,
	James Morse <james.morse@arm.com>,
	Julien Thierry <julien.thierry.kdev@gmail.com>,
	Suzuki K Poulose <suzuki.poulose@arm.com>,
	Dennis Zhou <dennis@kernel.org>, Tejun Heo <tj@kernel.org>,
	Christoph Lameter <cl@linux.com>,
	Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>,
	Sudeep Holla <sudeep.holla@arm.com>,
	linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org,
	linux-arm-kernel@lists.infradead.org, kernel-team@android.com
Subject: Re: [PATCH v3 02/23] psci: Accessor for configured PSCI function IDs
Date: Thu, 26 Nov 2020 17:24:50 +0000	[thread overview]
Message-ID: <20201126172450.GC38486@C02TD0UTHF1T.local> (raw)
In-Reply-To: <20201126155421.14901-3-dbrazdil@google.com>

On Thu, Nov 26, 2020 at 03:54:00PM +0000, David Brazdil wrote:
> Function IDs used by PSCI are configurable for v0.1 via DT/APCI. If the
> host is using PSCI v0.1, KVM's host PSCI proxy needs to use the same IDs.
> Expose the array holding the information with a read-only accessor.
> 
> Signed-off-by: David Brazdil <dbrazdil@google.com>
> ---
>  drivers/firmware/psci/psci.c | 16 ++++++++--------
>  include/linux/psci.h         | 10 ++++++++++
>  2 files changed, 18 insertions(+), 8 deletions(-)
> 
> diff --git a/drivers/firmware/psci/psci.c b/drivers/firmware/psci/psci.c
> index 213c68418a65..40609564595e 100644
> --- a/drivers/firmware/psci/psci.c
> +++ b/drivers/firmware/psci/psci.c
> @@ -58,16 +58,16 @@ typedef unsigned long (psci_fn)(unsigned long, unsigned long,
>  				unsigned long, unsigned long);
>  static psci_fn *invoke_psci_fn;
>  
> -enum psci_function {
> -	PSCI_FN_CPU_SUSPEND,
> -	PSCI_FN_CPU_ON,
> -	PSCI_FN_CPU_OFF,
> -	PSCI_FN_MIGRATE,
> -	PSCI_FN_MAX,
> -};
> -
>  static u32 psci_function_id[PSCI_FN_MAX];
>  
> +u32 psci_get_function_id(enum psci_function fn)
> +{
> +	if (WARN_ON_ONCE(fn < 0 || fn >= PSCI_FN_MAX))
> +		return 0;
> +
> +	return psci_function_id[fn];
> +}

I'd really like if we could namespace this with a psci_0_1_* prefix
before we expose it outside of the PSCI code. I appreciate that's a
larger change, but I reckon we only need a couple of new patches:

1) Split the ops which consume the FN ids into separate psci_0_1_*() and
   psci_0_2_*() variants, with a common __psci_*() helper that takes the
   function ID as an argument. The 0_1 variants would read the function
   ID from a variable, and the 0_2 variants would hard-code the id.

2) Replace the psci_function_id array with:

   struct psci_0_1_function_ids {
   	u32 suspend;
   	u32 cpu_on;
   	u32 cpu_off;
   	u32 migrate;
   };

   ... and remove enum psci_function entirely.

3) Add a helper which returns the entire psci_0_1_function_ids struct in
   one go. No warnings necessary.

Does that sound OK to you?

Thanks,
Mark.

> +
>  #define PSCI_0_2_POWER_STATE_MASK		\
>  				(PSCI_0_2_POWER_STATE_ID_MASK | \
>  				PSCI_0_2_POWER_STATE_TYPE_MASK | \
> diff --git a/include/linux/psci.h b/include/linux/psci.h
> index 2a1bfb890e58..5b49a5c82d6f 100644
> --- a/include/linux/psci.h
> +++ b/include/linux/psci.h
> @@ -21,6 +21,16 @@ bool psci_power_state_is_valid(u32 state);
>  int psci_set_osi_mode(bool enable);
>  bool psci_has_osi_support(void);
>  
> +enum psci_function {
> +	PSCI_FN_CPU_SUSPEND,
> +	PSCI_FN_CPU_ON,
> +	PSCI_FN_CPU_OFF,
> +	PSCI_FN_MIGRATE,
> +	PSCI_FN_MAX,
> +};
> +
> +u32 psci_get_function_id(enum psci_function fn);
> +
>  struct psci_operations {
>  	u32 (*get_version)(void);
>  	int (*cpu_suspend)(u32 state, unsigned long entry_point);
> -- 
> 2.29.2.454.gaff20da3a2-goog
> 

  reply	other threads:[~2020-11-26 17:25 UTC|newest]

Thread overview: 49+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-11-26 15:53 [PATCH v3 00/23] Opt-in always-on nVHE hypervisor David Brazdil
2020-11-26 15:53 ` [PATCH v3 01/23] psci: Support psci_ops.get_version for v0.1 David Brazdil
2020-11-26 17:21   ` Mark Rutland
2020-11-26 15:54 ` [PATCH v3 02/23] psci: Accessor for configured PSCI function IDs David Brazdil
2020-11-26 17:24   ` Mark Rutland [this message]
2020-11-26 17:29     ` David Brazdil
2020-11-26 17:34   ` Lorenzo Pieralisi
2020-11-26 15:54 ` [PATCH v3 03/23] arm64: Make cpu_logical_map() take unsigned int David Brazdil
2020-11-26 17:28   ` Mark Rutland
2020-12-02 15:44     ` David Brazdil
2020-11-26 15:54 ` [PATCH v3 04/23] arm64: Move MAIR_EL1_SET to asm/memory.h David Brazdil
2020-11-26 17:35   ` Mark Rutland
2020-12-01 13:58     ` David Brazdil
2020-11-26 15:54 ` [PATCH v3 05/23] arm64: Extract parts of el2_setup into a macro David Brazdil
2020-11-26 18:06   ` Mark Rutland
2020-12-01 13:55     ` David Brazdil
2020-11-26 15:54 ` [PATCH v3 06/23] kvm: arm64: Add kvm-arm.protected early kernel parameter David Brazdil
2020-11-27 16:32   ` Sudeep Holla
2020-12-01 13:19     ` David Brazdil
2020-12-01 14:07       ` Mark Rutland
2020-12-01 14:43         ` David Brazdil
2020-12-01 14:58           ` Mark Rutland
2020-11-26 15:54 ` [PATCH v3 07/23] kvm: arm64: Initialize MAIR_EL2 using a constant David Brazdil
2020-11-26 15:54 ` [PATCH v3 08/23] kvm: arm64: Remove vector_ptr param of hyp-init David Brazdil
2020-11-26 15:54 ` [PATCH v3 09/23] kvm: arm64: Move hyp-init params to a per-CPU struct David Brazdil
2020-11-26 15:54 ` [PATCH v3 10/23] kvm: arm64: Add .hyp.data..ro_after_init ELF section David Brazdil
2020-11-26 15:54 ` [PATCH v3 11/23] kvm: arm64: Support per_cpu_ptr in nVHE hyp code David Brazdil
2020-11-26 15:54 ` [PATCH v3 12/23] kvm: arm64: Create nVHE copy of cpu_logical_map David Brazdil
2020-11-26 15:54 ` [PATCH v3 13/23] kvm: arm64: Add SMC handler in nVHE EL2 David Brazdil
2020-11-26 15:54 ` [PATCH v3 14/23] kvm: arm64: Bootstrap PSCI " David Brazdil
2020-11-26 15:54 ` [PATCH v3 15/23] kvm: arm64: Add offset for hyp VA <-> PA conversion David Brazdil
2020-11-26 15:54 ` [PATCH v3 16/23] kvm: arm64: Forward safe PSCI SMCs coming from host David Brazdil
2020-11-27 10:14   ` Lorenzo Pieralisi
2020-12-02 17:49     ` David Brazdil
2020-11-27 16:51   ` Sudeep Holla
2020-12-01 13:20     ` David Brazdil
2020-11-26 15:54 ` [PATCH v3 17/23] kvm: arm64: Extract __do_hyp_init into a helper function David Brazdil
2020-11-26 15:54 ` [PATCH v3 18/23] kvm: arm64: Add function to enter host from KVM nVHE hyp code David Brazdil
2020-11-26 15:54 ` [PATCH v3 19/23] kvm: arm64: Intercept host's CPU_ON SMCs David Brazdil
2020-11-27 17:47   ` Sudeep Holla
2020-12-01 13:51     ` David Brazdil
2020-11-26 15:54 ` [PATCH v3 20/23] kvm: arm64: Intercept host's CPU_SUSPEND PSCI SMCs David Brazdil
2020-12-01 14:57   ` Mark Rutland
2020-11-26 15:54 ` [PATCH v3 21/23] kvm: arm64: Keep nVHE EL2 vector installed David Brazdil
2020-11-26 15:54 ` [PATCH v3 22/23] kvm: arm64: Trap host SMCs in protected mode David Brazdil
2020-11-26 15:54 ` [PATCH v3 23/23] kvm: arm64: Fix EL2 mode availability checks David Brazdil
2020-11-26 15:57 ` [PATCH v3 00/23] Opt-in always-on nVHE hypervisor Matthew Wilcox
2020-11-26 16:19   ` Marc Zyngier
2020-11-26 16:23     ` Matthew Wilcox

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