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kernel/include/linux/surface_aggregator/controller.h
Maximilian Luz 03ee318391 platform/surface: aggregator: Make SSAM_DEFINE_SYNC_REQUEST_x define static functions 
The SSAM_DEFINE_SYNC_REQUEST_x() macros are intended to reduce
boiler-plate code for SSAM request definitions by defining a wrapper
function for the specified request. The client device variants of those
macros, i.e. SSAM_DEFINE_SYNC_REQUEST_CL_x() in particular rely on the
multi-device (MD) variants, e.g.:

    #define SSAM_DEFINE_SYNC_REQUEST_CL_R(name, rtype, spec...)   \
        SSAM_DEFINE_SYNC_REQUEST_MD_R(__raw_##name, rtype, spec)  \
        int name(struct ssam_device *sdev, rtype *ret)            \
        {                                                         \
            return __raw_##name(sdev->ctrl, sdev->uid.target,     \
                                sdev->uid.instance, ret);         \
        }

This now creates the problem that it is not possible to declare the
generated functions static via

    static SSAM_DEFINE_SYNC_REQUEST_CL_R(...)

as this will only apply to the function defined by the multi-device
macro, i.e. SSAM_DEFINE_SYNC_REQUEST_MD_R(). Thus compiling with
`-Wmissing-prototypes' rightfully complains that there is a 'static'
keyword missing.

To solve this, make all SSAM_DEFINE_SYNC_REQUEST_x() macros define
static functions. Non-client-device macros are also changed for
consistency. In general, we expect those functions to be only used
locally in the respective drivers for the corresponding interfaces, so
having to define a wrapper function to be able to export this should be
the odd case out.

Reported-by: kernel test robot <lkp@intel.com>
Fixes: b78b4982d7 ("platform/surface: Add platform profile driver")
Signed-off-by: Maximilian Luz <luzmaximilian@gmail.com>
Link: https://lore.kernel.org/r/20210304190524.1172197-1-luzmaximilian@gmail.com
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
2021-03-08 11:33:28 +01:00

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/* SPDX-License-Identifier: GPL-2.0+ */
/*
* Surface System Aggregator Module (SSAM) controller interface.
*
* Main communication interface for the SSAM EC. Provides a controller
* managing access and communication to and from the SSAM EC, as well as main
* communication structures and definitions.
*
* Copyright (C) 2019-2020 Maximilian Luz <luzmaximilian@gmail.com>
*/
#ifndef _LINUX_SURFACE_AGGREGATOR_CONTROLLER_H
#define _LINUX_SURFACE_AGGREGATOR_CONTROLLER_H
#include <linux/completion.h>
#include <linux/device.h>
#include <linux/types.h>
#include <linux/surface_aggregator/serial_hub.h>
/* -- Main data types and definitions --------------------------------------- */
/**
* enum ssam_event_flags - Flags for enabling/disabling SAM events
* @SSAM_EVENT_SEQUENCED: The event will be sent via a sequenced data frame.
*/
enum ssam_event_flags {
SSAM_EVENT_SEQUENCED = BIT(0),
};
/**
* struct ssam_event - SAM event sent from the EC to the host.
* @target_category: Target category of the event source. See &enum ssam_ssh_tc.
* @target_id: Target ID of the event source.
* @command_id: Command ID of the event.
* @instance_id: Instance ID of the event source.
* @length: Length of the event payload in bytes.
* @data: Event payload data.
*/
struct ssam_event {
u8 target_category;
u8 target_id;
u8 command_id;
u8 instance_id;
u16 length;
u8 data[];
};
/**
* enum ssam_request_flags - Flags for SAM requests.
*
* @SSAM_REQUEST_HAS_RESPONSE:
* Specifies that the request expects a response. If not set, the request
* will be directly completed after its underlying packet has been
* transmitted. If set, the request transport system waits for a response
* of the request.
*
* @SSAM_REQUEST_UNSEQUENCED:
* Specifies that the request should be transmitted via an unsequenced
* packet. If set, the request must not have a response, meaning that this
* flag and the %SSAM_REQUEST_HAS_RESPONSE flag are mutually exclusive.
*/
enum ssam_request_flags {
SSAM_REQUEST_HAS_RESPONSE = BIT(0),
SSAM_REQUEST_UNSEQUENCED = BIT(1),
};
/**
* struct ssam_request - SAM request description.
* @target_category: Category of the request's target. See &enum ssam_ssh_tc.
* @target_id: ID of the request's target.
* @command_id: Command ID of the request.
* @instance_id: Instance ID of the request's target.
* @flags: Flags for the request. See &enum ssam_request_flags.
* @length: Length of the request payload in bytes.
* @payload: Request payload data.
*
* This struct fully describes a SAM request with payload. It is intended to
* help set up the actual transport struct, e.g. &struct ssam_request_sync,
* and specifically its raw message data via ssam_request_write_data().
*/
struct ssam_request {
u8 target_category;
u8 target_id;
u8 command_id;
u8 instance_id;
u16 flags;
u16 length;
const u8 *payload;
};
/**
* struct ssam_response - Response buffer for SAM request.
* @capacity: Capacity of the buffer, in bytes.
* @length: Length of the actual data stored in the memory pointed to by
* @pointer, in bytes. Set by the transport system.
* @pointer: Pointer to the buffer's memory, storing the response payload data.
*/
struct ssam_response {
size_t capacity;
size_t length;
u8 *pointer;
};
struct ssam_controller;
struct ssam_controller *ssam_get_controller(void);
struct ssam_controller *ssam_client_bind(struct device *client);
int ssam_client_link(struct ssam_controller *ctrl, struct device *client);
struct device *ssam_controller_device(struct ssam_controller *c);
struct ssam_controller *ssam_controller_get(struct ssam_controller *c);
void ssam_controller_put(struct ssam_controller *c);
void ssam_controller_statelock(struct ssam_controller *c);
void ssam_controller_stateunlock(struct ssam_controller *c);
ssize_t ssam_request_write_data(struct ssam_span *buf,
struct ssam_controller *ctrl,
const struct ssam_request *spec);
/* -- Synchronous request interface. ---------------------------------------- */
/**
* struct ssam_request_sync - Synchronous SAM request struct.
* @base: Underlying SSH request.
* @comp: Completion used to signal full completion of the request. After the
* request has been submitted, this struct may only be modified or
* deallocated after the completion has been signaled.
* request has been submitted,
* @resp: Buffer to store the response.
* @status: Status of the request, set after the base request has been
* completed or has failed.
*/
struct ssam_request_sync {
struct ssh_request base;
struct completion comp;
struct ssam_response *resp;
int status;
};
int ssam_request_sync_alloc(size_t payload_len, gfp_t flags,
struct ssam_request_sync **rqst,
struct ssam_span *buffer);
void ssam_request_sync_free(struct ssam_request_sync *rqst);
int ssam_request_sync_init(struct ssam_request_sync *rqst,
enum ssam_request_flags flags);
/**
* ssam_request_sync_set_data - Set message data of a synchronous request.
* @rqst: The request.
* @ptr: Pointer to the request message data.
* @len: Length of the request message data.
*
* Set the request message data of a synchronous request. The provided buffer
* needs to live until the request has been completed.
*/
static inline void ssam_request_sync_set_data(struct ssam_request_sync *rqst,
u8 *ptr, size_t len)
{
ssh_request_set_data(&rqst->base, ptr, len);
}
/**
* ssam_request_sync_set_resp - Set response buffer of a synchronous request.
* @rqst: The request.
* @resp: The response buffer.
*
* Sets the response buffer of a synchronous request. This buffer will store
* the response of the request after it has been completed. May be %NULL if no
* response is expected.
*/
static inline void ssam_request_sync_set_resp(struct ssam_request_sync *rqst,
struct ssam_response *resp)
{
rqst->resp = resp;
}
int ssam_request_sync_submit(struct ssam_controller *ctrl,
struct ssam_request_sync *rqst);
/**
* ssam_request_sync_wait - Wait for completion of a synchronous request.
* @rqst: The request to wait for.
*
* Wait for completion and release of a synchronous request. After this
* function terminates, the request is guaranteed to have left the transport
* system. After successful submission of a request, this function must be
* called before accessing the response of the request, freeing the request,
* or freeing any of the buffers associated with the request.
*
* This function must not be called if the request has not been submitted yet
* and may lead to a deadlock/infinite wait if a subsequent request submission
* fails in that case, due to the completion never triggering.
*
* Return: Returns the status of the given request, which is set on completion
* of the packet. This value is zero on success and negative on failure.
*/
static inline int ssam_request_sync_wait(struct ssam_request_sync *rqst)
{
wait_for_completion(&rqst->comp);
return rqst->status;
}
int ssam_request_sync(struct ssam_controller *ctrl,
const struct ssam_request *spec,
struct ssam_response *rsp);
int ssam_request_sync_with_buffer(struct ssam_controller *ctrl,
const struct ssam_request *spec,
struct ssam_response *rsp,
struct ssam_span *buf);
/**
* ssam_request_sync_onstack - Execute a synchronous request on the stack.
* @ctrl: The controller via which the request is submitted.
* @rqst: The request specification.
* @rsp: The response buffer.
* @payload_len: The (maximum) request payload length.
*
* Allocates a synchronous request with specified payload length on the stack,
* fully initializes it via the provided request specification, submits it,
* and finally waits for its completion before returning its status. This
* helper macro essentially allocates the request message buffer on the stack
* and then calls ssam_request_sync_with_buffer().
*
* Note: The @payload_len parameter specifies the maximum payload length, used
* for buffer allocation. The actual payload length may be smaller.
*
* Return: Returns the status of the request or any failure during setup, i.e.
* zero on success and a negative value on failure.
*/
#define ssam_request_sync_onstack(ctrl, rqst, rsp, payload_len) \
({ \
u8 __data[SSH_COMMAND_MESSAGE_LENGTH(payload_len)]; \
struct ssam_span __buf = { &__data[0], ARRAY_SIZE(__data) }; \
\
ssam_request_sync_with_buffer(ctrl, rqst, rsp, &__buf); \
})
/**
* __ssam_retry - Retry request in case of I/O errors or timeouts.
* @request: The request function to execute. Must return an integer.
* @n: Number of tries.
* @args: Arguments for the request function.
*
* Executes the given request function, i.e. calls @request. In case the
* request returns %-EREMOTEIO (indicates I/O error) or %-ETIMEDOUT (request
* or underlying packet timed out), @request will be re-executed again, up to
* @n times in total.
*
* Return: Returns the return value of the last execution of @request.
*/
#define __ssam_retry(request, n, args...) \
({ \
int __i, __s = 0; \
\
for (__i = (n); __i > 0; __i--) { \
__s = request(args); \
if (__s != -ETIMEDOUT && __s != -EREMOTEIO) \
break; \
} \
__s; \
})
/**
* ssam_retry - Retry request in case of I/O errors or timeouts up to three
* times in total.
* @request: The request function to execute. Must return an integer.
* @args: Arguments for the request function.
*
* Executes the given request function, i.e. calls @request. In case the
* request returns %-EREMOTEIO (indicates I/O error) or -%ETIMEDOUT (request
* or underlying packet timed out), @request will be re-executed again, up to
* three times in total.
*
* See __ssam_retry() for a more generic macro for this purpose.
*
* Return: Returns the return value of the last execution of @request.
*/
#define ssam_retry(request, args...) \
__ssam_retry(request, 3, args)
/**
* struct ssam_request_spec - Blue-print specification of SAM request.
* @target_category: Category of the request's target. See &enum ssam_ssh_tc.
* @target_id: ID of the request's target.
* @command_id: Command ID of the request.
* @instance_id: Instance ID of the request's target.
* @flags: Flags for the request. See &enum ssam_request_flags.
*
* Blue-print specification for a SAM request. This struct describes the
* unique static parameters of a request (i.e. type) without specifying any of
* its instance-specific data (e.g. payload). It is intended to be used as base
* for defining simple request functions via the
* ``SSAM_DEFINE_SYNC_REQUEST_x()`` family of macros.
*/
struct ssam_request_spec {
u8 target_category;
u8 target_id;
u8 command_id;
u8 instance_id;
u8 flags;
};
/**
* struct ssam_request_spec_md - Blue-print specification for multi-device SAM
* request.
* @target_category: Category of the request's target. See &enum ssam_ssh_tc.
* @command_id: Command ID of the request.
* @flags: Flags for the request. See &enum ssam_request_flags.
*
* Blue-print specification for a multi-device SAM request, i.e. a request
* that is applicable to multiple device instances, described by their
* individual target and instance IDs. This struct describes the unique static
* parameters of a request (i.e. type) without specifying any of its
* instance-specific data (e.g. payload) and without specifying any of its
* device specific IDs (i.e. target and instance ID). It is intended to be
* used as base for defining simple multi-device request functions via the
* ``SSAM_DEFINE_SYNC_REQUEST_MD_x()`` and ``SSAM_DEFINE_SYNC_REQUEST_CL_x()``
* families of macros.
*/
struct ssam_request_spec_md {
u8 target_category;
u8 command_id;
u8 flags;
};
/**
* SSAM_DEFINE_SYNC_REQUEST_N() - Define synchronous SAM request function
* with neither argument nor return value.
* @name: Name of the generated function.
* @spec: Specification (&struct ssam_request_spec) defining the request.
*
* Defines a function executing the synchronous SAM request specified by
* @spec, with the request having neither argument nor return value. The
* generated function takes care of setting up the request struct and buffer
* allocation, as well as execution of the request itself, returning once the
* request has been fully completed. The required transport buffer will be
* allocated on the stack.
*
* The generated function is defined as ``static int name(struct
* ssam_controller *ctrl)``, returning the status of the request, which is
* zero on success and negative on failure. The ``ctrl`` parameter is the
* controller via which the request is being sent.
*
* Refer to ssam_request_sync_onstack() for more details on the behavior of
* the generated function.
*/
#define SSAM_DEFINE_SYNC_REQUEST_N(name, spec...) \
static int name(struct ssam_controller *ctrl) \
{ \
struct ssam_request_spec s = (struct ssam_request_spec)spec; \
struct ssam_request rqst; \
\
rqst.target_category = s.target_category; \
rqst.target_id = s.target_id; \
rqst.command_id = s.command_id; \
rqst.instance_id = s.instance_id; \
rqst.flags = s.flags; \
rqst.length = 0; \
rqst.payload = NULL; \
\
return ssam_request_sync_onstack(ctrl, &rqst, NULL, 0); \
}
/**
* SSAM_DEFINE_SYNC_REQUEST_W() - Define synchronous SAM request function with
* argument.
* @name: Name of the generated function.
* @atype: Type of the request's argument.
* @spec: Specification (&struct ssam_request_spec) defining the request.
*
* Defines a function executing the synchronous SAM request specified by
* @spec, with the request taking an argument of type @atype and having no
* return value. The generated function takes care of setting up the request
* struct, buffer allocation, as well as execution of the request itself,
* returning once the request has been fully completed. The required transport
* buffer will be allocated on the stack.
*
* The generated function is defined as ``static int name(struct
* ssam_controller *ctrl, const atype *arg)``, returning the status of the
* request, which is zero on success and negative on failure. The ``ctrl``
* parameter is the controller via which the request is sent. The request
* argument is specified via the ``arg`` pointer.
*
* Refer to ssam_request_sync_onstack() for more details on the behavior of
* the generated function.
*/
#define SSAM_DEFINE_SYNC_REQUEST_W(name, atype, spec...) \
static int name(struct ssam_controller *ctrl, const atype *arg) \
{ \
struct ssam_request_spec s = (struct ssam_request_spec)spec; \
struct ssam_request rqst; \
\
rqst.target_category = s.target_category; \
rqst.target_id = s.target_id; \
rqst.command_id = s.command_id; \
rqst.instance_id = s.instance_id; \
rqst.flags = s.flags; \
rqst.length = sizeof(atype); \
rqst.payload = (u8 *)arg; \
\
return ssam_request_sync_onstack(ctrl, &rqst, NULL, \
sizeof(atype)); \
}
/**
* SSAM_DEFINE_SYNC_REQUEST_R() - Define synchronous SAM request function with
* return value.
* @name: Name of the generated function.
* @rtype: Type of the request's return value.
* @spec: Specification (&struct ssam_request_spec) defining the request.
*
* Defines a function executing the synchronous SAM request specified by
* @spec, with the request taking no argument but having a return value of
* type @rtype. The generated function takes care of setting up the request
* and response structs, buffer allocation, as well as execution of the
* request itself, returning once the request has been fully completed. The
* required transport buffer will be allocated on the stack.
*
* The generated function is defined as ``static int name(struct
* ssam_controller *ctrl, rtype *ret)``, returning the status of the request,
* which is zero on success and negative on failure. The ``ctrl`` parameter is
* the controller via which the request is sent. The request's return value is
* written to the memory pointed to by the ``ret`` parameter.
*
* Refer to ssam_request_sync_onstack() for more details on the behavior of
* the generated function.
*/
#define SSAM_DEFINE_SYNC_REQUEST_R(name, rtype, spec...) \
static int name(struct ssam_controller *ctrl, rtype *ret) \
{ \
struct ssam_request_spec s = (struct ssam_request_spec)spec; \
struct ssam_request rqst; \
struct ssam_response rsp; \
int status; \
\
rqst.target_category = s.target_category; \
rqst.target_id = s.target_id; \
rqst.command_id = s.command_id; \
rqst.instance_id = s.instance_id; \
rqst.flags = s.flags | SSAM_REQUEST_HAS_RESPONSE; \
rqst.length = 0; \
rqst.payload = NULL; \
\
rsp.capacity = sizeof(rtype); \
rsp.length = 0; \
rsp.pointer = (u8 *)ret; \
\
status = ssam_request_sync_onstack(ctrl, &rqst, &rsp, 0); \
if (status) \
return status; \
\
if (rsp.length != sizeof(rtype)) { \
struct device *dev = ssam_controller_device(ctrl); \
dev_err(dev, \
"rqst: invalid response length, expected %zu, got %zu (tc: %#04x, cid: %#04x)", \
sizeof(rtype), rsp.length, rqst.target_category,\
rqst.command_id); \
return -EIO; \
} \
\
return 0; \
}
/**
* SSAM_DEFINE_SYNC_REQUEST_MD_N() - Define synchronous multi-device SAM
* request function with neither argument nor return value.
* @name: Name of the generated function.
* @spec: Specification (&struct ssam_request_spec_md) defining the request.
*
* Defines a function executing the synchronous SAM request specified by
* @spec, with the request having neither argument nor return value. Device
* specifying parameters are not hard-coded, but instead must be provided to
* the function. The generated function takes care of setting up the request
* struct, buffer allocation, as well as execution of the request itself,
* returning once the request has been fully completed. The required transport
* buffer will be allocated on the stack.
*
* The generated function is defined as ``static int name(struct
* ssam_controller *ctrl, u8 tid, u8 iid)``, returning the status of the
* request, which is zero on success and negative on failure. The ``ctrl``
* parameter is the controller via which the request is sent, ``tid`` the
* target ID for the request, and ``iid`` the instance ID.
*
* Refer to ssam_request_sync_onstack() for more details on the behavior of
* the generated function.
*/
#define SSAM_DEFINE_SYNC_REQUEST_MD_N(name, spec...) \
static int name(struct ssam_controller *ctrl, u8 tid, u8 iid) \
{ \
struct ssam_request_spec_md s = (struct ssam_request_spec_md)spec; \
struct ssam_request rqst; \
\
rqst.target_category = s.target_category; \
rqst.target_id = tid; \
rqst.command_id = s.command_id; \
rqst.instance_id = iid; \
rqst.flags = s.flags; \
rqst.length = 0; \
rqst.payload = NULL; \
\
return ssam_request_sync_onstack(ctrl, &rqst, NULL, 0); \
}
/**
* SSAM_DEFINE_SYNC_REQUEST_MD_W() - Define synchronous multi-device SAM
* request function with argument.
* @name: Name of the generated function.
* @atype: Type of the request's argument.
* @spec: Specification (&struct ssam_request_spec_md) defining the request.
*
* Defines a function executing the synchronous SAM request specified by
* @spec, with the request taking an argument of type @atype and having no
* return value. Device specifying parameters are not hard-coded, but instead
* must be provided to the function. The generated function takes care of
* setting up the request struct, buffer allocation, as well as execution of
* the request itself, returning once the request has been fully completed.
* The required transport buffer will be allocated on the stack.
*
* The generated function is defined as ``static int name(struct
* ssam_controller *ctrl, u8 tid, u8 iid, const atype *arg)``, returning the
* status of the request, which is zero on success and negative on failure.
* The ``ctrl`` parameter is the controller via which the request is sent,
* ``tid`` the target ID for the request, and ``iid`` the instance ID. The
* request argument is specified via the ``arg`` pointer.
*
* Refer to ssam_request_sync_onstack() for more details on the behavior of
* the generated function.
*/
#define SSAM_DEFINE_SYNC_REQUEST_MD_W(name, atype, spec...) \
static int name(struct ssam_controller *ctrl, u8 tid, u8 iid, const atype *arg) \
{ \
struct ssam_request_spec_md s = (struct ssam_request_spec_md)spec; \
struct ssam_request rqst; \
\
rqst.target_category = s.target_category; \
rqst.target_id = tid; \
rqst.command_id = s.command_id; \
rqst.instance_id = iid; \
rqst.flags = s.flags; \
rqst.length = sizeof(atype); \
rqst.payload = (u8 *)arg; \
\
return ssam_request_sync_onstack(ctrl, &rqst, NULL, \
sizeof(atype)); \
}
/**
* SSAM_DEFINE_SYNC_REQUEST_MD_R() - Define synchronous multi-device SAM
* request function with return value.
* @name: Name of the generated function.
* @rtype: Type of the request's return value.
* @spec: Specification (&struct ssam_request_spec_md) defining the request.
*
* Defines a function executing the synchronous SAM request specified by
* @spec, with the request taking no argument but having a return value of
* type @rtype. Device specifying parameters are not hard-coded, but instead
* must be provided to the function. The generated function takes care of
* setting up the request and response structs, buffer allocation, as well as
* execution of the request itself, returning once the request has been fully
* completed. The required transport buffer will be allocated on the stack.
*
* The generated function is defined as ``static int name(struct
* ssam_controller *ctrl, u8 tid, u8 iid, rtype *ret)``, returning the status
* of the request, which is zero on success and negative on failure. The
* ``ctrl`` parameter is the controller via which the request is sent, ``tid``
* the target ID for the request, and ``iid`` the instance ID. The request's
* return value is written to the memory pointed to by the ``ret`` parameter.
*
* Refer to ssam_request_sync_onstack() for more details on the behavior of
* the generated function.
*/
#define SSAM_DEFINE_SYNC_REQUEST_MD_R(name, rtype, spec...) \
static int name(struct ssam_controller *ctrl, u8 tid, u8 iid, rtype *ret) \
{ \
struct ssam_request_spec_md s = (struct ssam_request_spec_md)spec; \
struct ssam_request rqst; \
struct ssam_response rsp; \
int status; \
\
rqst.target_category = s.target_category; \
rqst.target_id = tid; \
rqst.command_id = s.command_id; \
rqst.instance_id = iid; \
rqst.flags = s.flags | SSAM_REQUEST_HAS_RESPONSE; \
rqst.length = 0; \
rqst.payload = NULL; \
\
rsp.capacity = sizeof(rtype); \
rsp.length = 0; \
rsp.pointer = (u8 *)ret; \
\
status = ssam_request_sync_onstack(ctrl, &rqst, &rsp, 0); \
if (status) \
return status; \
\
if (rsp.length != sizeof(rtype)) { \
struct device *dev = ssam_controller_device(ctrl); \
dev_err(dev, \
"rqst: invalid response length, expected %zu, got %zu (tc: %#04x, cid: %#04x)", \
sizeof(rtype), rsp.length, rqst.target_category,\
rqst.command_id); \
return -EIO; \
} \
\
return 0; \
}
/* -- Event notifier/callbacks. --------------------------------------------- */
#define SSAM_NOTIF_STATE_SHIFT 2
#define SSAM_NOTIF_STATE_MASK ((1 << SSAM_NOTIF_STATE_SHIFT) - 1)
/**
* enum ssam_notif_flags - Flags used in return values from SSAM notifier
* callback functions.
*
* @SSAM_NOTIF_HANDLED:
* Indicates that the notification has been handled. This flag should be
* set by the handler if the handler can act/has acted upon the event
* provided to it. This flag should not be set if the handler is not a
* primary handler intended for the provided event.
*
* If this flag has not been set by any handler after the notifier chain
* has been traversed, a warning will be emitted, stating that the event
* has not been handled.
*
* @SSAM_NOTIF_STOP:
* Indicates that the notifier traversal should stop. If this flag is
* returned from a notifier callback, notifier chain traversal will
* immediately stop and any remaining notifiers will not be called. This
* flag is automatically set when ssam_notifier_from_errno() is called
* with a negative error value.
*/
enum ssam_notif_flags {
SSAM_NOTIF_HANDLED = BIT(0),
SSAM_NOTIF_STOP = BIT(1),
};
struct ssam_event_notifier;
typedef u32 (*ssam_notifier_fn_t)(struct ssam_event_notifier *nf,
const struct ssam_event *event);
/**
* struct ssam_notifier_block - Base notifier block for SSAM event
* notifications.
* @node: The node for the list of notifiers.
* @fn: The callback function of this notifier. This function takes the
* respective notifier block and event as input and should return
* a notifier value, which can either be obtained from the flags
* provided in &enum ssam_notif_flags, converted from a standard
* error value via ssam_notifier_from_errno(), or a combination of
* both (e.g. ``ssam_notifier_from_errno(e) | SSAM_NOTIF_HANDLED``).
* @priority: Priority value determining the order in which notifier callbacks
* will be called. A higher value means higher priority, i.e. the
* associated callback will be executed earlier than other (lower
* priority) callbacks.
*/
struct ssam_notifier_block {
struct list_head node;
ssam_notifier_fn_t fn;
int priority;
};
/**
* ssam_notifier_from_errno() - Convert standard error value to notifier
* return code.
* @err: The error code to convert, must be negative (in case of failure) or
* zero (in case of success).
*
* Return: Returns the notifier return value obtained by converting the
* specified @err value. In case @err is negative, the %SSAM_NOTIF_STOP flag
* will be set, causing notifier call chain traversal to abort.
*/
static inline u32 ssam_notifier_from_errno(int err)
{
if (WARN_ON(err > 0) || err == 0)
return 0;
else
return ((-err) << SSAM_NOTIF_STATE_SHIFT) | SSAM_NOTIF_STOP;
}
/**
* ssam_notifier_to_errno() - Convert notifier return code to standard error
* value.
* @ret: The notifier return value to convert.
*
* Return: Returns the negative error value encoded in @ret or zero if @ret
* indicates success.
*/
static inline int ssam_notifier_to_errno(u32 ret)
{
return -(ret >> SSAM_NOTIF_STATE_SHIFT);
}
/* -- Event/notification registry. ------------------------------------------ */
/**
* struct ssam_event_registry - Registry specification used for enabling events.
* @target_category: Target category for the event registry requests.
* @target_id: Target ID for the event registry requests.
* @cid_enable: Command ID for the event-enable request.
* @cid_disable: Command ID for the event-disable request.
*
* This struct describes a SAM event registry via the minimal collection of
* SAM IDs specifying the requests to use for enabling and disabling an event.
* The individual event to be enabled/disabled itself is specified via &struct
* ssam_event_id.
*/
struct ssam_event_registry {
u8 target_category;
u8 target_id;
u8 cid_enable;
u8 cid_disable;
};
/**
* struct ssam_event_id - Unique event ID used for enabling events.
* @target_category: Target category of the event source.
* @instance: Instance ID of the event source.
*
* This struct specifies the event to be enabled/disabled via an externally
* provided registry. It does not specify the registry to be used itself, this
* is done via &struct ssam_event_registry.
*/
struct ssam_event_id {
u8 target_category;
u8 instance;
};
/**
* enum ssam_event_mask - Flags specifying how events are matched to notifiers.
*
* @SSAM_EVENT_MASK_NONE:
* Run the callback for any event with matching target category. Do not
* do any additional filtering.
*
* @SSAM_EVENT_MASK_TARGET:
* In addition to filtering by target category, only execute the notifier
* callback for events with a target ID matching to the one of the
* registry used for enabling/disabling the event.
*
* @SSAM_EVENT_MASK_INSTANCE:
* In addition to filtering by target category, only execute the notifier
* callback for events with an instance ID matching to the instance ID
* used when enabling the event.
*
* @SSAM_EVENT_MASK_STRICT:
* Do all the filtering above.
*/
enum ssam_event_mask {
SSAM_EVENT_MASK_TARGET = BIT(0),
SSAM_EVENT_MASK_INSTANCE = BIT(1),
SSAM_EVENT_MASK_NONE = 0,
SSAM_EVENT_MASK_STRICT =
SSAM_EVENT_MASK_TARGET
| SSAM_EVENT_MASK_INSTANCE,
};
/**
* SSAM_EVENT_REGISTRY() - Define a new event registry.
* @tc: Target category for the event registry requests.
* @tid: Target ID for the event registry requests.
* @cid_en: Command ID for the event-enable request.
* @cid_dis: Command ID for the event-disable request.
*
* Return: Returns the &struct ssam_event_registry specified by the given
* parameters.
*/
#define SSAM_EVENT_REGISTRY(tc, tid, cid_en, cid_dis) \
((struct ssam_event_registry) { \
.target_category = (tc), \
.target_id = (tid), \
.cid_enable = (cid_en), \
.cid_disable = (cid_dis), \
})
#define SSAM_EVENT_REGISTRY_SAM \
SSAM_EVENT_REGISTRY(SSAM_SSH_TC_SAM, 0x01, 0x0b, 0x0c)
#define SSAM_EVENT_REGISTRY_KIP \
SSAM_EVENT_REGISTRY(SSAM_SSH_TC_KIP, 0x02, 0x27, 0x28)
#define SSAM_EVENT_REGISTRY_REG \
SSAM_EVENT_REGISTRY(SSAM_SSH_TC_REG, 0x02, 0x01, 0x02)
/**
* struct ssam_event_notifier - Notifier block for SSAM events.
* @base: The base notifier block with callback function and priority.
* @event: The event for which this block will receive notifications.
* @event.reg: Registry via which the event will be enabled/disabled.
* @event.id: ID specifying the event.
* @event.mask: Flags determining how events are matched to the notifier.
* @event.flags: Flags used for enabling the event.
*/
struct ssam_event_notifier {
struct ssam_notifier_block base;
struct {
struct ssam_event_registry reg;
struct ssam_event_id id;
enum ssam_event_mask mask;
u8 flags;
} event;
};
int ssam_notifier_register(struct ssam_controller *ctrl,
struct ssam_event_notifier *n);
int ssam_notifier_unregister(struct ssam_controller *ctrl,
struct ssam_event_notifier *n);
#endif /* _LINUX_SURFACE_AGGREGATOR_CONTROLLER_H */
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