[PATCH v6 02/12] ARM/ARM64: KVM: Add common header for PSCI related defines

Wed Apr 2 01:00:42 EDT 2014

On Wed, Apr 2, 2014 at 10:01 AM, Anup Patel <anup at brainfault.org> wrote:
> On Wed, Apr 2, 2014 at 9:52 AM, Rob Herring <rob.herring at linaro.org> wrote:
>> On Mon, Mar 31, 2014 at 5:46 AM, Anup Patel <anup.patel at linaro.org> 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 <anup.patel at linaro.org>
>>> Signed-off-by: Pranavkumar Sawargaonkar <pranavkumar at linaro.org>
>>> ---
>>>  include/uapi/linux/Kbuild |    1 +
>>>  include/uapi/linux/psci.h |   55 +++++++++++++++++++++++++++++++++++++++++++++
>>>  2 files changed, 56 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..41f727e
>>> --- /dev/null
>>> +++ b/include/uapi/linux/psci.h
>>> @@ -0,0 +1,55 @@
>>> +/*
>>> + * 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   Anup Patel <anup.patel at linaro.org>
>>
>> Like I told Ashwin, fix the copyright. You can be the author, but
>> Linaro is the copyright holder.
>
> Sure, I will update the copyright as-per your suggestion.
>
>>
>>> + */
>>> +
>>> +#ifndef _UAPI_LINUX_PSCI_H
>>> +#define _UAPI_LINUX_PSCI_H
>>> +
>>> +/* PSCI v0.1 interface */
>>> +#define PSCI_FN(base, n)                       ((base) + (n))
>>> +
>>> +#define PSCI_FN_CPU_SUSPEND(base)              PSCI_FN(base, 0)
>>> +#define PSCI_FN_CPU_OFF(base)                  PSCI_FN(base, 1)
>>> +#define PSCI_FN_CPU_ON(base)                   PSCI_FN(base, 2)
>>> +#define PSCI_FN_MIGRATE(base)                  PSCI_FN(base, 3)
>>> +
>>> +/* 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_FN64_BASE                     0xC4000000
>>> +#define PSCI_0_2_FN64(n)                       (PSCI_0_2_FN64_BASE + (n))
>>
>> This could be something like:
>>
>> #define PSCI_0_2_64BIT       0x40000000
>> #define PSCI_0_2_FN64(n)    (PSCI_0_2_FN_BASE + PSCI_0_2_64BIT + (n))
>>
>> It's also useful as you may want to be able to check for 64-bit calls.
>
> Good point.
>
> From PSCI emulation perspective, I did not face this situation but we might
> need this in future.
>
>>
>>> +
>>> +#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)
>>> +
>>> +/* PSCI return values */
>>> +#define PSCI_RET_SUCCESS                       0
>>> +#define PSCI_RET_NOT_SUPPORTED                 ((unsigned long)-1)
>>> +#define PSCI_RET_INVALID_PARAMS                        ((unsigned long)-2)
>>> +#define PSCI_RET_DENIED                                ((unsigned long)-3)
>>> +#define PSCI_RET_ALREADY_ON                    ((unsigned long)-4)
>>> +#define PSCI_RET_ON_PENDING                    ((unsigned long)-5)
>>> +#define PSCI_RET_INTERNAL_FAILURE              ((unsigned long)-6)
>>> +#define PSCI_RET_NOT_PRESENT                   ((unsigned long)-7)
>>> +#define PSCI_RET_DISABLED                      ((unsigned long)-8)
>>
>> These should not be cast. The return values are defined to be int32
>> independent of 64-bit or 32-bit calls.
>
> The cast is for ease of use in kernel and emulation code.
>
> With the cast in place, we can assign PSCI return values to signed
> as well as unsigned variables.

Never mind, I will update in-kernel PSCI emulation to do the typecasting
wherever required. This way we can keep this header closer to spec.

>
>>
>> Rob
>> _______________________________________________
>> kvmarm mailing list
>> kvmarm at lists.cs.columbia.edu
>> https://lists.cs.columbia.edu/mailman/listinfo/kvmarm
>
> --
> Anup

--
Anup