144 lines · c
1/* SPDX-License-Identifier: GPL-2.0+ */2/*3 * SSH request transport layer.4 *5 * Copyright (C) 2019-2022 Maximilian Luz <luzmaximilian@gmail.com>6 */7 8#ifndef _SURFACE_AGGREGATOR_SSH_REQUEST_LAYER_H9#define _SURFACE_AGGREGATOR_SSH_REQUEST_LAYER_H10 11#include <linux/atomic.h>12#include <linux/ktime.h>13#include <linux/list.h>14#include <linux/spinlock.h>15#include <linux/workqueue.h>16 17#include <linux/surface_aggregator/serial_hub.h>18#include <linux/surface_aggregator/controller.h>19 20#include "ssh_packet_layer.h"21 22/**23 * enum ssh_rtl_state_flags - State-flags for &struct ssh_rtl.24 *25 * @SSH_RTL_SF_SHUTDOWN_BIT:26 * Indicates that the request transport layer has been shut down or is27 * being shut down and should not accept any new requests.28 */29enum ssh_rtl_state_flags {30 SSH_RTL_SF_SHUTDOWN_BIT,31};32 33/**34 * struct ssh_rtl_ops - Callback operations for request transport layer.35 * @handle_event: Function called when a SSH event has been received. The36 * specified function takes the request layer, received command37 * struct, and corresponding payload as arguments. If the event38 * has no payload, the payload span is empty (not %NULL).39 */40struct ssh_rtl_ops {41 void (*handle_event)(struct ssh_rtl *rtl, const struct ssh_command *cmd,42 const struct ssam_span *data);43};44 45/**46 * struct ssh_rtl - SSH request transport layer.47 * @ptl: Underlying packet transport layer.48 * @state: State(-flags) of the transport layer.49 * @queue: Request submission queue.50 * @queue.lock: Lock for modifying the request submission queue.51 * @queue.head: List-head of the request submission queue.52 * @pending: Set/list of pending requests.53 * @pending.lock: Lock for modifying the request set.54 * @pending.head: List-head of the pending set/list.55 * @pending.count: Number of currently pending requests.56 * @tx: Transmitter subsystem.57 * @tx.work: Transmitter work item.58 * @rtx_timeout: Retransmission timeout subsystem.59 * @rtx_timeout.lock: Lock for modifying the retransmission timeout reaper.60 * @rtx_timeout.timeout: Timeout interval for retransmission.61 * @rtx_timeout.expires: Time specifying when the reaper work is next scheduled.62 * @rtx_timeout.reaper: Work performing timeout checks and subsequent actions.63 * @ops: Request layer operations.64 */65struct ssh_rtl {66 struct ssh_ptl ptl;67 unsigned long state;68 69 struct {70 spinlock_t lock;71 struct list_head head;72 } queue;73 74 struct {75 spinlock_t lock;76 struct list_head head;77 atomic_t count;78 } pending;79 80 struct {81 struct work_struct work;82 } tx;83 84 struct {85 spinlock_t lock;86 ktime_t timeout;87 ktime_t expires;88 struct delayed_work reaper;89 } rtx_timeout;90 91 struct ssh_rtl_ops ops;92};93 94#define rtl_dbg(r, fmt, ...) ptl_dbg(&(r)->ptl, fmt, ##__VA_ARGS__)95#define rtl_info(p, fmt, ...) ptl_info(&(p)->ptl, fmt, ##__VA_ARGS__)96#define rtl_warn(r, fmt, ...) ptl_warn(&(r)->ptl, fmt, ##__VA_ARGS__)97#define rtl_err(r, fmt, ...) ptl_err(&(r)->ptl, fmt, ##__VA_ARGS__)98#define rtl_dbg_cond(r, fmt, ...) __ssam_prcond(rtl_dbg, r, fmt, ##__VA_ARGS__)99 100#define to_ssh_rtl(ptr, member) \101 container_of(ptr, struct ssh_rtl, member)102 103/**104 * ssh_rtl_get_device() - Get device associated with request transport layer.105 * @rtl: The request transport layer.106 *107 * Return: Returns the device on which the given request transport layer108 * builds upon.109 */110static inline struct device *ssh_rtl_get_device(struct ssh_rtl *rtl)111{112 return ssh_ptl_get_device(&rtl->ptl);113}114 115/**116 * ssh_request_rtl() - Get request transport layer associated with request.117 * @rqst: The request to get the request transport layer reference for.118 *119 * Return: Returns the &struct ssh_rtl associated with the given SSH request.120 */121static inline struct ssh_rtl *ssh_request_rtl(struct ssh_request *rqst)122{123 struct ssh_ptl *ptl;124 125 ptl = READ_ONCE(rqst->packet.ptl);126 return likely(ptl) ? to_ssh_rtl(ptl, ptl) : NULL;127}128 129int ssh_rtl_submit(struct ssh_rtl *rtl, struct ssh_request *rqst);130bool ssh_rtl_cancel(struct ssh_request *rqst, bool pending);131 132int ssh_rtl_init(struct ssh_rtl *rtl, struct serdev_device *serdev,133 const struct ssh_rtl_ops *ops);134 135int ssh_rtl_start(struct ssh_rtl *rtl);136int ssh_rtl_flush(struct ssh_rtl *rtl, unsigned long timeout);137void ssh_rtl_shutdown(struct ssh_rtl *rtl);138void ssh_rtl_destroy(struct ssh_rtl *rtl);139 140int ssh_request_init(struct ssh_request *rqst, enum ssam_request_flags flags,141 const struct ssh_request_ops *ops);142 143#endif /* _SURFACE_AGGREGATOR_SSH_REQUEST_LAYER_H */144