cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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ssh_request_layer.h (4555B)

      1/* SPDX-License-Identifier: GPL-2.0+ */
      2/*
      3 * SSH request transport layer.
      4 *
      5 * Copyright (C) 2019-2021 Maximilian Luz <luzmaximilian@gmail.com>
      6 */
      7
      8#ifndef _SURFACE_AGGREGATOR_SSH_REQUEST_LAYER_H
      9#define _SURFACE_AGGREGATOR_SSH_REQUEST_LAYER_H
     10
     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 is
     27 *	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. The
     36 *                specified function takes the request layer, received command
     37 *                struct, and corresponding payload as arguments. If the event
     38 *                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 layer
    108 * 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 */