source: mainline/kernel/generic/include/cpu.h@ a3d87b9

Last change on this file since a3d87b9 was 6a0e568, checked in by Jiří Zárevúcky <zarevucky.jiri@…>, 21 months ago

Allow fast-switch to another runnable thread

When a thread is available that can be switched to immediately
without having to block, do so without a detour through CPU
scheduler context. The new thread will handle whatever cannot
be done while the previous context is active on a CPU, such as
requeuing the thread or deallocation.

  • Property mode set to 100644
File size: 3.6 KB
Line 
1/*
2 * Copyright (c) 2001-2004 Jakub Jermar
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 *
9 * - Redistributions of source code must retain the above copyright
10 * notice, this list of conditions and the following disclaimer.
11 * - Redistributions in binary form must reproduce the above copyright
12 * notice, this list of conditions and the following disclaimer in the
13 * documentation and/or other materials provided with the distribution.
14 * - The name of the author may not be used to endorse or promote products
15 * derived from this software without specific prior written permission.
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
18 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
19 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
20 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
21 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
22 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
26 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27 */
28
29/** @addtogroup kernel_generic
30 * @{
31 */
32/** @file
33 */
34
35#ifndef KERN_CPU_H_
36#define KERN_CPU_H_
37
38#include <mm/tlb.h>
39#include <synch/spinlock.h>
40#include <proc/scheduler.h>
41#include <arch/cpu.h>
42#include <arch/context.h>
43#include <adt/list.h>
44#include <arch.h>
45
46#define CPU (CURRENT->cpu)
47#define CPU_LOCAL (&CPU->local)
48
49/**
50 * Contents of CPU_LOCAL. These are variables that are only ever accessed by
51 * the CPU they belong to, so they don't need any synchronization,
52 * just locally disabled interrupts.
53 */
54typedef struct cpu_local {
55 /**
56 * When system clock loses a tick, it is
57 * recorded here so that clock() can react.
58 */
59 size_t missed_clock_ticks;
60
61 uint64_t current_clock_tick;
62 uint64_t preempt_deadline; /* < when should the currently running thread be preempted */
63 uint64_t relink_deadline;
64
65 /**
66 * Stack used by scheduler when there is no running thread.
67 * This field is unchanged after initialization.
68 */
69 uint8_t *stack;
70
71 /**
72 * Processor cycle accounting.
73 */
74 bool idle;
75 uint64_t last_cycle;
76
77 context_t scheduler_context;
78
79 struct thread *prev_thread;
80 state_t exiting_state;
81} cpu_local_t;
82
83/** CPU structure.
84 *
85 * There is one structure like this for every processor.
86 */
87typedef struct cpu {
88 IRQ_SPINLOCK_DECLARE(tlb_lock);
89
90 tlb_shootdown_msg_t tlb_messages[TLB_MESSAGE_QUEUE_LEN];
91 size_t tlb_messages_count;
92
93 atomic_size_t nrdy;
94 runq_t rq[RQ_COUNT];
95
96 IRQ_SPINLOCK_DECLARE(timeoutlock);
97 list_t timeout_active_list;
98
99 /**
100 * Processor cycle accounting.
101 */
102 atomic_time_stat_t idle_cycles;
103 atomic_time_stat_t busy_cycles;
104
105 /**
106 * Processor ID assigned by kernel.
107 */
108 unsigned int id;
109
110 bool active;
111 volatile bool tlb_active;
112
113 uint16_t frequency_mhz;
114 uint32_t delay_loop_const;
115
116 cpu_arch_t arch;
117
118#ifdef CONFIG_FPU_LAZY
119 /* For synchronization between FPU trap and thread destructor. */
120 IRQ_SPINLOCK_DECLARE(fpu_lock);
121#endif
122 _Atomic(struct thread *) fpu_owner;
123
124 cpu_local_t local;
125} cpu_t;
126
127extern cpu_t *cpus;
128
129extern void cpu_init(void);
130extern void cpu_list(void);
131
132extern void cpu_arch_init(void);
133extern void cpu_identify(void);
134extern void cpu_print_report(cpu_t *);
135
136#endif
137
138/** @}
139 */
Note: See TracBrowser for help on using the repository browser.