Subject: [PATCH v10 02/12] ARM/ARM64: KVM: Add common header for PSCI related defines

From: [email-masked] (Christoffer Dall)
Date: Mon, 28 Apr 2014 07:16:56 -0700

On Mon, Apr 21, 2014 at 06:29:56PM +0530, Anup Patel wrote:
> We need a common place to share PSCI related defines among ARM kernel,
> ARM64 kernel, KVM ARM/ARM64 PSCI emulation, and user space.
> 
> We introduce uapi/linux/psci.h for this purpose. This newly added
> header will be first used by KVM ARM/ARM64 in-kernel PSCI emulation
> and user space (i.e. QEMU or KVMTOOL).
> 
> Signed-off-by: Anup Patel <[email-masked]>
> Signed-off-by: Pranavkumar Sawargaonkar <[email-masked]>
> Signed-off-by: Ashwin Chaugule <[email-masked]>
> ---
>  include/uapi/linux/Kbuild |    1 +
>  include/uapi/linux/psci.h |   85 +++++++++++++++++++++++++++++++++++++++++++++
>  2 files changed, 86 insertions(+)
>  create mode 100644 include/uapi/linux/psci.h
> 
> diff --git a/include/uapi/linux/Kbuild b/include/uapi/linux/Kbuild
> index 6929571..24e9033 100644
> --- a/include/uapi/linux/Kbuild
> +++ b/include/uapi/linux/Kbuild
> @@ -317,6 +317,7 @@ header-y += ppp-ioctl.h
>  header-y += ppp_defs.h
>  header-y += pps.h
>  header-y += prctl.h
> +header-y += psci.h
>  header-y += ptp_clock.h
>  header-y += ptrace.h
>  header-y += qnx4_fs.h
> diff --git a/include/uapi/linux/psci.h b/include/uapi/linux/psci.h
> new file mode 100644
> index 0000000..0d4a136
> --- /dev/null
> +++ b/include/uapi/linux/psci.h
> @@ -0,0 +1,85 @@
> +/*
> + * ARM Power State and Coordination Interface (PSCI) header
> + *
> + * This header holds common PSCI defines and macros shared
> + * by: ARM kernel, ARM64 kernel, KVM ARM/ARM64 and user space.
> + *
> + * Copyright (C) 2014 Linaro Ltd.
> + * Author: Anup Patel <[email-masked]>
> + */
> +
> +#ifndef _UAPI_LINUX_PSCI_H
> +#define _UAPI_LINUX_PSCI_H
> +
> +/*
> + * PSCI v0.1 interface
> + *
> + * The PSCI v0.1 function numbers are implementation defined.
> + *
> + * Only PSCI return values such as: SUCCESS, NOT_SUPPORTED,
> + * INVALID_PARAMS, and DENIED defined below are applicable
> + * to PSCI v0.1.
> + */
> +
> +/* PSCI v0.2 interface */
> +#define PSCI_0_2_FN_BASE			0x84000000
> +#define PSCI_0_2_FN(n)				(PSCI_0_2_FN_BASE + (n))
> +#define PSCI_0_2_64BIT				0x40000000
> +#define PSCI_0_2_FN64_BASE			\
> +					(PSCI_0_2_FN_BASE + PSCI_0_2_64BIT)
> +#define PSCI_0_2_FN64(n)			(PSCI_0_2_FN64_BASE + (n))
> +
> +#define PSCI_0_2_FN_PSCI_VERSION		PSCI_0_2_FN(0)
> +#define PSCI_0_2_FN_CPU_SUSPEND			PSCI_0_2_FN(1)
> +#define PSCI_0_2_FN_CPU_OFF			PSCI_0_2_FN(2)
> +#define PSCI_0_2_FN_CPU_ON			PSCI_0_2_FN(3)
> +#define PSCI_0_2_FN_AFFINITY_INFO		PSCI_0_2_FN(4)
> +#define PSCI_0_2_FN_MIGRATE			PSCI_0_2_FN(5)
> +#define PSCI_0_2_FN_MIGRATE_INFO_TYPE		PSCI_0_2_FN(6)
> +#define PSCI_0_2_FN_MIGRATE_INFO_UP_CPU		PSCI_0_2_FN(7)
> +#define PSCI_0_2_FN_SYSTEM_OFF			PSCI_0_2_FN(8)
> +#define PSCI_0_2_FN_SYSTEM_RESET		PSCI_0_2_FN(9)
> +
> +#define PSCI_0_2_FN64_CPU_SUSPEND		PSCI_0_2_FN64(1)
> +#define PSCI_0_2_FN64_CPU_ON			PSCI_0_2_FN64(3)
> +#define PSCI_0_2_FN64_AFFINITY_INFO		PSCI_0_2_FN64(4)
> +#define PSCI_0_2_FN64_MIGRATE			PSCI_0_2_FN64(5)
> +#define PSCI_0_2_FN64_MIGRATE_INFO_UP_CPU	PSCI_0_2_FN64(7)
> +
> +#define PSCI_0_2_POWER_STATE_ID_MASK		0xffff
> +#define PSCI_0_2_POWER_STATE_ID_SHIFT		0
> +#define PSCI_0_2_POWER_STATE_TYPE_MASK		0x1

Shouldn't this be (0x1 << PSCI_0_2_POWER_STATE_TYPE_SHIFT)?

That seems to be the definition of a mask in the PSCI_VERSION_MAJOR_MASK
below,@least be consistent in this file.

> +#define PSCI_0_2_POWER_STATE_TYPE_SHIFT		16
> +#define PSCI_0_2_POWER_STATE_AFFL_MASK		0x3

same

> +#define PSCI_0_2_POWER_STATE_AFFL_SHIFT		24
> +
> +#define PSCI_0_2_AFFINITY_LEVEL_ON		0
> +#define PSCI_0_2_AFFINITY_LEVEL_OFF		1
> +#define PSCI_0_2_AFFINITY_LEVEL_ON_PENDING	2

I'm confused, what do these defines signify?  I spent 10 minutes looking
at the spec and now I think that you probably mean AFFINITY_INFO and
that these are the possible return values?  Probably warrants a comment.

> +
> +#define PSCI_0_2_TOS_UP_MIGRATE			0
> +#define PSCI_0_2_TOS_UP_NO_MIGRATE		1
> +#define PSCI_0_2_TOS_MP				2

Should probably also comment that "TOS" are return values for
MIGRATE_INFO_TYPE.

> +
> +/* PSCI version decoding (independent of PSCI version) */
> +#define PSCI_VERSION_MAJOR_SHIFT		16
> +#define PSCI_VERSION_MINOR_MASK			\
> +		((1U << PSCI_VERSION_MAJOR_SHIFT) - 1)
> +#define PSCI_VERSION_MAJOR_MASK			~PSCI_VERSION_MINOR_MASK
> +#define PSCI_VERSION_MAJOR(ver)			\
> +		(((ver) & PSCI_VERSION_MAJOR_MASK) >> PSCI_VERSION_MAJOR_SHIFT)
> +#define PSCI_VERSION_MINOR(ver)			\
> +		((ver) & PSCI_VERSION_MINOR_MASK)

I find this really complicated compared to "#define MINOR_MASK 0xffff"
and "#define MAJOR_MASK 0xffff0000" but whatever...

> +
> +/* PSCI return values (inclusive of all PSCI versions) */
> +#define PSCI_RET_SUCCESS			0
> +#define PSCI_RET_NOT_SUPPORTED			-1
> +#define PSCI_RET_INVALID_PARAMS			-2
> +#define PSCI_RET_DENIED				-3
> +#define PSCI_RET_ALREADY_ON			-4
> +#define PSCI_RET_ON_PENDING			-5
> +#define PSCI_RET_INTERNAL_FAILURE		-6
> +#define PSCI_RET_NOT_PRESENT			-7
> +#define PSCI_RET_DISABLED			-8
> +
> +#endif /* _UAPI_LINUX_PSCI_H */
> -- 
> 1.7.9.5
> 

-Christoffer