sched: minor refactor

arch/at91sam3x8e/include/arch/hardware.h

@@ -29,7 +29,7 @@ struct reg_sw_snapshot {
 	 * lr is saved by hardware, but we need to store it twice
 	 * because the IRQ entry overwrites it
 	 */
-	void *lr;	/* alias r14 */
+	uintptr_t lr;	/* alias r14 */
 };
 
 /**
@@ -42,8 +42,8 @@ struct reg_hw_snapshot {
 	word_t r2;
 	word_t r3;
 	word_t r12;
-	void *lr;	/* alias r14 */
+	uintptr_t lr;	/* alias r14 */
-	void *pc;	/* alias r15 */
+	uintptr_t pc;	/* alias r15 */
 	word_t psr;
 };
 

arch/at91sam3x8e/sched.c

@@ -9,8 +9,6 @@
 
 #include <string.h>
 
-extern struct task *_sched_current_task;
-
 void irq_sys_tick(void)
 {
 	/*
@@ -63,15 +61,15 @@ void arch_sched_task_init(struct task *task, void (*entry)(void))
 	task->sp = regs;
 
 	memset(regs, 0, sizeof(*regs));
-	regs->hw.pc = entry;
+	regs->hw.pc = (uintptr_t)entry;
 	regs->hw.psr = 0x01000000U;
-	regs->sw.lr = (void *)0xFFFFFFF9U;
+	regs->sw.lr = 0xfffffff9U;
 }
 
-void sched_yield(enum task_state state)
+void yield(enum task_state state)
 {
 	REG_SYSTICK_VAL = 0U; /* Reset timer */
-	_sched_current_task->state = state;
+	current->state = state;
 	arch_irq_invoke(IRQNO_PEND_SV);
 }
 

include/ardix/sched.h

@@ -6,20 +6,12 @@
 #include <ardix/list.h>
 #include <ardix/types.h>
 
-#ifndef CONFIG_SCHED_MAXTASK
+#include <config.h>
-/** The maximum number of tasks. */
-#define CONFIG_SCHED_MAXTASK 8
-#endif
 
 #if CONFIG_SCHED_MAXTASK > 64
 #warning "CONFIG_SCHED_MAXTASK is > 64, this could have a significant performance impact"
 #endif
 
-#ifndef CONFIG_SCHED_INTR_FREQ
-/** Frequency (in Hertz) at which a scheduling interrupt should be fired */
-#define CONFIG_SCHED_INTR_FREQ 10000U
-#endif
-
 #ifndef CONFIG_STACKSZ
 /** Per-task stack size in bytes */
 #define CONFIG_STACKSZ 4096U
@@ -54,6 +46,8 @@ struct task {
 	pid_t pid;
 };
 
+extern struct task *current;
+
 /**
  * Initialize the scheduler subsystem.
  * This sets up a hardware interrupt timer (SysTick for Cortex-M3).
@@ -86,7 +80,7 @@ struct task *sched_task_clone(struct task *task);
  * @param state: State the task should enter.
  *	Allowed values are `TASK_SLEEP` and `TASK_IOWAIT`.
  */
-void sched_yield(enum task_state state);
+void yield(enum task_state state);
 
 /*
  * This file is part of Ardix.

kernel/sched.c

@@ -15,13 +15,13 @@
 extern uint32_t _sstack;
 extern uint32_t _estack;
 
-static struct task *_sched_tasktab[CONFIG_SCHED_MAXTASK];
+static struct task *tasktab[CONFIG_SCHED_MAXTASK];
-struct task *_sched_current_task;
+struct task *current;
 
 static void task_destroy(struct kent *kent)
 {
 	struct task *task = container_of(kent, struct task, kent);
-	_sched_tasktab[task->pid] = NULL;
+	tasktab[task->pid] = NULL;
 	free(task);
 }
 
@@ -29,27 +29,27 @@ int sched_init(void)
 {
 	int i;
 
-	_sched_current_task = malloc(sizeof(*_sched_current_task));
+	current = malloc(sizeof(*current));
-	if (_sched_current_task == NULL)
+	if (current == NULL)
 		return -ENOMEM;
 
-	_sched_current_task->kent.parent = kent_root;
+	current->kent.parent = kent_root;
-	_sched_current_task->kent.destroy = task_destroy;
+	current->kent.destroy = task_destroy;
-	i = kent_init(&_sched_current_task->kent);
+	i = kent_init(&current->kent);
 	if (i == 0) {
-		_sched_current_task->sp = &_sstack;
+		current->sp = &_sstack;
-		_sched_current_task->stack_bottom = &_estack;
+		current->stack_bottom = &_estack;
-		_sched_current_task->pid = 0;
+		current->pid = 0;
-		_sched_current_task->state = TASK_READY;
+		current->state = TASK_READY;
-		_sched_tasktab[0] = _sched_current_task;
+		tasktab[0] = current;
 
 		for (i = 1; i < CONFIG_SCHED_MAXTASK; i++)
-			_sched_tasktab[i] = NULL;
+			tasktab[i] = NULL;
 
 		i = arch_watchdog_init();
 
 		if (i == 0)
-			i = arch_sched_hwtimer_init(CONFIG_SCHED_MAXTASK);
+			i = arch_sched_hwtimer_init(CONFIG_SCHED_FREQ);
 	}
 
 	/*
@@ -79,26 +79,26 @@ static inline bool sched_task_should_run(const struct task *task)
 void *sched_process_switch(void *curr_sp)
 {
 	struct task *tmp;
-	pid_t nextpid = _sched_current_task->pid;
+	pid_t nextpid = current->pid;
-	_sched_current_task->sp = curr_sp;
+	current->sp = curr_sp;
 
-	if (_sched_current_task->state != TASK_SLEEP && _sched_current_task->state != TASK_IOWAIT)
+	if (current->state != TASK_SLEEP && current->state != TASK_IOWAIT)
-		_sched_current_task->state = TASK_QUEUE;
+		current->state = TASK_QUEUE;
 
 	while (1) {
 		nextpid++;
 		nextpid %= CONFIG_SCHED_MAXTASK;
 
-		tmp = _sched_tasktab[nextpid];
+		tmp = tasktab[nextpid];
 		if (tmp != NULL && sched_task_should_run(tmp)) {
-			_sched_current_task = tmp;
+			current = tmp;
 			break;
 		}
 		/* TODO: Add idle thread */
 	}
 
-	_sched_current_task->state = TASK_READY;
+	current->state = TASK_READY;
-	return _sched_current_task->sp;
+	return current->sp;
 }
 
 struct task *sched_fork(struct task *parent)
@@ -110,7 +110,7 @@ struct task *sched_fork(struct task *parent)
 		goto err_alloc;
 
 	for (pid = 0; pid < CONFIG_SCHED_MAXTASK; pid++) {
-		if (_sched_tasktab[pid] == NULL)
+		if (tasktab[pid] == NULL)
 			break;
 	}
 	if (pid == CONFIG_SCHED_MAXTASK)
@@ -131,11 +131,6 @@ err_alloc:
 	return NULL;
 }
 
-struct task *sched_current_task(void)
-{
-	return _sched_current_task;
-}
-
 /*
  * This file is part of Ardix.
  * Copyright (c) 2020, 2021 Felix Kopp <owo@fef.moe>.