diff options
author | Ian Moffett <ian@osmora.org> | 2024-06-23 22:25:13 -0400 |
---|---|---|
committer | Ian Moffett <ian@osmora.org> | 2024-06-23 22:30:35 -0400 |
commit | 00245135a7df4028df60f62f4041c1302e5b3381 (patch) | |
tree | 5a3ae4e1421f3463fc4b90774ed3fc322adac66f /sys | |
parent | aa8d940e7e1cadf651054a58d6953fee03149587 (diff) |
kernel: sched: Add PCB and context switching
Signed-off-by: Ian Moffett <ian@osmora.org>
Diffstat (limited to 'sys')
-rw-r--r-- | sys/include/arch/amd64/pcb.h | 40 | ||||
-rw-r--r-- | sys/include/sys/proc.h | 11 | ||||
-rw-r--r-- | sys/include/sys/sched.h | 3 | ||||
-rw-r--r-- | sys/kern/kern_sched.c | 83 |
4 files changed, 132 insertions, 5 deletions
diff --git a/sys/include/arch/amd64/pcb.h b/sys/include/arch/amd64/pcb.h new file mode 100644 index 0000000..5d06ade --- /dev/null +++ b/sys/include/arch/amd64/pcb.h @@ -0,0 +1,40 @@ +/* + * Copyright (c) 2023-2024 Ian Marco Moffett and the Osmora Team. + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions are met: + * + * 1. Redistributions of source code must retain the above copyright notice, + * this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * 3. Neither the name of Hyra nor the names of its + * contributors may be used to endorse or promote products derived from + * this software without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" + * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE + * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR + * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF + * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS + * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN + * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) + * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE + * POSSIBILITY OF SUCH DAMAGE. + */ + +#ifndef _MACHINE_PCB_H_ +#define _MACHINE_PCB_H_ + +#include <sys/types.h> +#include <vm/pmap.h> + +struct pcb { + struct vas addrsp; +}; + +#endif /* !_MACHINE_PCB_H_ */ diff --git a/sys/include/sys/proc.h b/sys/include/sys/proc.h index ba47a5c..b74cb00 100644 --- a/sys/include/sys/proc.h +++ b/sys/include/sys/proc.h @@ -32,17 +32,24 @@ #include <sys/types.h> #include <sys/spinlock.h> +#include <sys/queue.h> #if defined(_KERNEL) -#include <machine/cpu.h> #include <machine/frame.h> +#include <machine/pcb.h> #endif /* _KERNEL */ #if defined(_KERNEL) struct proc { pid_t pid; - struct cpu_info *cpu; + struct trapframe tf; + struct pcb pcb; + size_t priority; + uintptr_t stack_base; + TAILQ_ENTRY(proc) link; }; +struct proc *this_td(void); + #endif /* _KERNEL */ #endif /* !_SYS_PROC_H_ */ diff --git a/sys/include/sys/sched.h b/sys/include/sys/sched.h index 33d546d..ae59d5f 100644 --- a/sys/include/sys/sched.h +++ b/sys/include/sys/sched.h @@ -30,10 +30,13 @@ #ifndef _SYS_SCHED_H_ #define _SYS_SCHED_H_ +#include <sys/proc.h> + #if defined(_KERNEL) void sched_init(void); void sched_enter(void); +void sched_enqueue_td(struct proc *td); #endif /* _KERNEL */ #endif /* !_SYS_SCHED_H_ */ diff --git a/sys/kern/kern_sched.c b/sys/kern/kern_sched.c index b79d682..c370311 100644 --- a/sys/kern/kern_sched.c +++ b/sys/kern/kern_sched.c @@ -33,8 +33,11 @@ #include <sys/cdefs.h> #include <sys/syslog.h> #include <machine/frame.h> +#include <machine/cpu.h> +#include <vm/pmap.h> #include <dev/timer.h> #include <assert.h> +#include <string.h> #define pr_trace(fmt, ...) kprintf("ksched: " fmt, ##__VA_ARGS__) @@ -49,6 +52,12 @@ static sched_policy_t policy = SCHED_POLICY_RR; static struct sched_queue qlist[SCHED_NQUEUE]; /* + * Thread queue lock - all operations to `qlist' + * must be done with this lock acquired. + */ +__cacheline_aligned static struct spinlock tdq_lock = {0}; + +/* * Perform timer oneshot */ static inline void @@ -64,6 +73,54 @@ sched_oneshot(bool now) timer.oneshot_us(usec); } +static struct proc * +sched_dequeue_td(void) +{ + struct sched_queue *queue; + struct proc *td = NULL; + + spinlock_acquire(&tdq_lock); + + for (size_t i = 0; i < SCHED_NQUEUE; ++i) { + queue = &qlist[i]; + if (!TAILQ_EMPTY(&queue->q)) { + td = TAILQ_FIRST(&queue->q); + TAILQ_REMOVE(&queue->q, td, link); + break; + } + } + + spinlock_release(&tdq_lock); + return td; +} + +/* + * Add a thread to the scheduler. + */ +void +sched_enqueue_td(struct proc *td) +{ + struct sched_queue *queue; + + spinlock_acquire(&tdq_lock); + queue = &qlist[td->priority]; + + TAILQ_INSERT_TAIL(&queue->q, td, link); + spinlock_release(&tdq_lock); +} + +/* + * Return the currently running thread. + */ +struct proc * +this_td(void) +{ + struct cpu_info *ci; + + ci = this_cpu(); + return ci->curtd; +} + /* * Perform a context switch. * @@ -72,10 +129,30 @@ sched_oneshot(bool now) void sched_switch(struct trapframe *tf) { - static struct spinlock lock = {0}; + struct cpu_info *ci; + struct pcb *pcbp; + struct proc *next_td, *td; + + ci = this_cpu(); + td = ci->curtd; + + /* Do we have threads to switch to? */ + if ((next_td = sched_dequeue_td()) == NULL) { + sched_oneshot(false); + return; + } + + /* Re-enqueue the old thread */ + if (td != NULL) { + memcpy(&td->tf, tf, sizeof(td->tf)); + sched_enqueue_td(td); + } + + memcpy(tf, &next_td->tf, sizeof(*tf)); + ci->curtd = next_td; + pcbp = &next_td->pcb; - spinlock_acquire(&lock); - spinlock_release(&lock); + pmap_switch_vas(pcbp->addrsp); sched_oneshot(false); } |