[PATCH] powerpc, powernv: Add OPAL platform event driver
Neelesh Gupta
neelegup at linux.vnet.ibm.com
Tue Sep 30 15:23:29 EST 2014
On 09/29/2014 03:53 PM, Anshuman Khandual wrote:
> This patch creates a new OPAL platform event character driver
> which will give userspace clients the access to these events
> and process them effectively. Following platforms events are
> currently supported with this platform driver.
>
> (1) Environmental and Power Warning (EPOW)
> (2) Delayed Power Off (DPO)
>
> The user interface for this driver is /dev/opal_event character
> device file where the user space clients can poll and read for
> new opal platform events. The expected sequence of events driven
> from user space should be like the following.
>
> (1) Open the character device file
> (2) Poll on the file for POLLIN event
> (3) When unblocked, must attempt to read PLAT_EVENT_MAX_SIZE size
> (4) Kernel driver will pass at most one opal_plat_event structure
> (5) Poll again for more new events
>
> The driver registers for OPAL messages notifications corresponding to
> individual OPAL events. When any of those event messages arrive in the
> kernel, the callbacks are called to process them which in turn unblocks
> the polling thread on the character device file. The driver also registers
> a timer function which will be called after a threshold amount of time to
> shutdown the system. The user space client receives the timeout value for
> all individual OPAL platform events and hence must prepare the system and
> eventually shutdown. In case the user client does not shutdown the system,
> the timer function will be called after the threshold and shutdown the
> system explicitly.
>
> Signed-off-by: Anshuman Khandual <khandual at linux.vnet.ibm.com>
Reviewed-by: Neelesh Gupta <neelegup at linux.vnet.ibm.com>
- Neelesh
> ---
> arch/powerpc/include/asm/opal.h | 45 +-
> .../include/uapi/asm/opal_platform_events.h | 90 +++
> arch/powerpc/platforms/powernv/Makefile | 2 +-
> .../platforms/powernv/opal-platform-events.c | 737 +++++++++++++++++++++
> arch/powerpc/platforms/powernv/opal-wrappers.S | 1 +
> arch/powerpc/platforms/powernv/opal.c | 8 +-
> 6 files changed, 880 insertions(+), 3 deletions(-)
> create mode 100644 arch/powerpc/include/uapi/asm/opal_platform_events.h
> create mode 100644 arch/powerpc/platforms/powernv/opal-platform-events.c
>
> diff --git a/arch/powerpc/include/asm/opal.h b/arch/powerpc/include/asm/opal.h
> index 86055e5..c134137 100644
> --- a/arch/powerpc/include/asm/opal.h
> +++ b/arch/powerpc/include/asm/opal.h
> @@ -151,6 +151,7 @@ struct opal_sg_list {
> #define OPAL_HANDLE_HMI 98
> #define OPAL_REGISTER_DUMP_REGION 101
> #define OPAL_UNREGISTER_DUMP_REGION 102
> +#define OPAL_GET_DPO_STATUS 105
>
> #ifndef __ASSEMBLY__
>
> @@ -249,6 +250,7 @@ enum OpalMessageType {
> OPAL_MSG_EPOW,
> OPAL_MSG_SHUTDOWN,
> OPAL_MSG_HMI_EVT,
> + OPAL_MSG_DPO,
> OPAL_MSG_TYPE_MAX,
> };
>
> @@ -417,6 +419,46 @@ struct opal_msg {
> __be64 params[8];
> };
>
> +/*
> + * EPOW status sharing (OPAL and the host)
> + *
> + * The host will pass on OPAL, a buffer of length OPAL_SYSEPOW_MAX
> + * with individual elements being 16 bits wide to fetch the system
> + * wide EPOW status. Each element in the buffer will contain the
> + * EPOW status in it's bit representation for a particular EPOW sub
> + * class as defiend here. So multiple detailed EPOW status bits
> + * specific for any sub class can be represented in a single buffer
> + * element as it's bit representation.
> + */
> +
> +/* System EPOW type */
> +enum OpalSysEpow {
> + OPAL_SYSEPOW_POWER = 0, /* Power EPOW */
> + OPAL_SYSEPOW_TEMP = 1, /* Temperature EPOW */
> + OPAL_SYSEPOW_COOLING = 2, /* Cooling EPOW */
> + OPAL_SYSEPOW_MAX = 3, /* Max EPOW categories */
> +};
> +
> +/* Power EPOW */
> +enum OpalSysPower {
> + OPAL_SYSPOWER_UPS = 0x0001, /* System on UPS power */
> + OPAL_SYSPOWER_CHNG = 0x0002, /* System power config change */
> + OPAL_SYSPOWER_FAIL = 0x0004, /* System impending power failure */
> + OPAL_SYSPOWER_INCL = 0x0008, /* System incomplete power */
> +};
> +
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