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Diffstat (limited to 'core/riscv-rv32i/task.c')
| -rw-r--r-- | core/riscv-rv32i/task.c | 725 |
1 files changed, 0 insertions, 725 deletions
diff --git a/core/riscv-rv32i/task.c b/core/riscv-rv32i/task.c deleted file mode 100644 index 558177e969..0000000000 --- a/core/riscv-rv32i/task.c +++ /dev/null @@ -1,725 +0,0 @@ -/* Copyright 2019 The Chromium OS Authors. All rights reserved. - * Use of this source code is governed by a BSD-style license that can be - * found in the LICENSE file. - */ - -/* Task scheduling / events module for Chrome EC operating system */ - -#include "atomic.h" -#include "console.h" -#include "cpu.h" -#include "irq_chip.h" -#include "link_defs.h" -#include "task.h" -#include "timer.h" -#include "util.h" - -typedef struct { - /* - * Note that sp must be the first element in the task struct - * for __switchto() to work. - */ - uint32_t sp; /* Saved stack pointer for context switch */ - uint32_t events; /* Bitmaps of received events */ - uint64_t runtime; /* Time spent in task */ - uint32_t *stack; /* Start of stack */ -} task_; - -/* Value to store in unused stack */ -#define STACK_UNUSED_VALUE 0xdeadd00d - -/* declare task routine prototypes */ -#define TASK(n, r, d, s) void r(void *); -void __idle(void); -CONFIG_TASK_LIST -CONFIG_TEST_TASK_LIST -#undef TASK - -/* Task names for easier debugging */ -#define TASK(n, r, d, s) #n, -static const char * const task_names[] = { - "<< idle >>", - CONFIG_TASK_LIST - CONFIG_TEST_TASK_LIST -}; -#undef TASK - -#ifdef CONFIG_TASK_PROFILING -static int task_will_switch; -static uint32_t exc_sub_time; -static uint64_t task_start_time; /* Time task scheduling started */ -static uint32_t exc_start_time; /* Time of task->exception transition */ -static uint32_t exc_end_time; /* Time of exception->task transition */ -static uint64_t exc_total_time; /* Total time in exceptions */ -static uint32_t svc_calls; /* Number of service calls */ -static uint32_t task_switches; /* Number of times active task changed */ -static uint32_t irq_dist[CONFIG_IRQ_COUNT]; /* Distribution of IRQ calls */ -#endif - -extern int __task_start(void); - -#if defined(CHIP_FAMILY_IT83XX) -extern void clock_sleep_mode_wakeup_isr(void); -#endif - -#ifndef CONFIG_LOW_POWER_IDLE -/* Idle task. Executed when no tasks are ready to be scheduled. */ -void __idle(void) -{ - /* - * Print when the idle task starts. This is the lowest priority task, - * so this only starts once all other tasks have gotten a chance to do - * their task inits and have gone to sleep. - */ - cprints(CC_TASK, "idle task started"); - - while (1) { -#if defined(CHIP_FAMILY_IT83XX) - /* doze mode */ - IT83XX_ECPM_PLLCTRL = EC_PLL_DOZE; - clock_cpu_standby(); -#else - asm("wfi"); -#endif - } -} -#endif /* !CONFIG_LOW_POWER_IDLE */ - -static void task_exit_trap(void) -{ - int i = task_get_current(); - - cprints(CC_TASK, "Task %d (%s) exited!", i, task_names[i]); - /* Exited tasks simply sleep forever */ - while (1) - task_wait_event(-1); -} - -/* Startup parameters for all tasks. */ -#define TASK(n, r, d, s) { \ - .a0 = (uint32_t)d, \ - .pc = (uint32_t)r, \ - .stack_size = s, \ -}, -static const struct { - uint32_t a0; - uint32_t pc; - uint16_t stack_size; -} tasks_init[] = { - TASK(IDLE, __idle, 0, IDLE_TASK_STACK_SIZE) - CONFIG_TASK_LIST - CONFIG_TEST_TASK_LIST -}; -#undef TASK - -/* Contexts for all tasks */ -static task_ tasks[TASK_ID_COUNT] __attribute__ ((section(".bss.tasks"))); -/* Validity checks about static task invariants */ -BUILD_ASSERT(TASK_ID_COUNT <= (sizeof(unsigned) * 8)); -BUILD_ASSERT(TASK_ID_COUNT < (1 << (sizeof(task_id_t) * 8))); - -/* Stacks for all tasks */ -#define TASK(n, r, d, s) + s -uint8_t task_stacks[0 - TASK(IDLE, __idle, 0, IDLE_TASK_STACK_SIZE) - CONFIG_TASK_LIST - CONFIG_TEST_TASK_LIST -] __aligned(8); - -#undef TASK - -/* Reserve space to discard context on first context switch. */ -uint32_t scratchpad[TASK_SCRATCHPAD_SIZE] __attribute__ - ((section(".bss.task_scratchpad"))); - -task_ *current_task = (task_ *)scratchpad; - -/* - * Should IRQs chain to svc_handler()? This should be set if either of the - * following is true: - * - * 1) Task scheduling has started, and task profiling is enabled. Task - * profiling does its tracking in svc_handler(). - * - * 2) An event was set by an interrupt; this could result in a higher-priority - * task unblocking. After checking for a task switch, svc_handler() will clear - * the flag (unless profiling is also enabled; then the flag remains set). - */ -int need_resched; - -/* - * Bitmap of all tasks ready to be run. - * - * Start off with only the hooks task marked as ready such that all the modules - * can do their init within a task switching context. The hooks task will then - * make a call to enable all tasks. - */ -static uint32_t tasks_ready = BIT(TASK_ID_HOOKS); -/* - * Initially allow only the HOOKS and IDLE task to run, regardless of ready - * status, in order for HOOK_INIT to complete before other tasks. - * task_enable_all_tasks() will open the flood gates. - */ -static uint32_t tasks_enabled = BIT(TASK_ID_HOOKS) | BIT(TASK_ID_IDLE); - -int start_called; /* Has task swapping started */ - -/* in interrupt context */ -volatile bool in_interrupt; -/* Interrupt number of EC modules */ -volatile int ec_int; -/* Interrupt group of EC INTC modules */ -volatile int ec_int_group; -/* interrupt number of sw interrupt */ -static int sw_int_num; -/* This variable is used to save return address register at EC reset. */ -uint32_t ec_reset_lp; -/* - * This variable is used to save return address register, - * and it is updated at the beginning of each ISR. - */ -uint32_t ira; - -static inline task_ *__task_id_to_ptr(task_id_t id) -{ - return tasks + id; -} - -void __ram_code interrupt_disable(void) -{ - /* bit11: disable MEIE */ - asm volatile ("li t0, 0x800"); - asm volatile ("csrc mie, t0"); -} - -void __ram_code interrupt_enable(void) -{ - /* bit11: enable MEIE */ - asm volatile ("li t0, 0x800"); - asm volatile ("csrs mie, t0"); -} - -inline int is_interrupt_enabled(void) -{ - int mie = 0; - - asm volatile ("csrr %0, mie" : "=r"(mie)); - - /* Check if MEIE bit is set in MIE register */ - return !!(mie & 0x800); -} - -inline int in_interrupt_context(void) -{ - return in_interrupt; -} - -int in_soft_interrupt_context(void) -{ - /* group 16 is reserved for soft-irq */ - return in_interrupt_context() && ec_int_group == 16; -} - -task_id_t __ram_code task_get_current(void) -{ -#ifdef CONFIG_DEBUG_BRINGUP - /* If we haven't done a context switch then our task ID isn't valid */ - ASSERT(current_task != (task_ *)scratchpad); -#endif - return current_task - tasks; -} - -uint32_t * __ram_code task_get_event_bitmap(task_id_t tskid) -{ - task_ *tsk = __task_id_to_ptr(tskid); - - return &tsk->events; -} - -int task_start_called(void) -{ - return start_called; -} - -/** - * Scheduling system call - * - * Also includes emulation of software triggering interrupt vector - */ -void __ram_code __keep syscall_handler(int desched, task_id_t resched, - int swirq) -{ - /* are we emulating an interrupt ? */ - if (swirq) { - void (*handler)(void) = __irqhandler[swirq]; - /* adjust IPC to return *after* the syscall instruction */ - set_mepc(get_mepc() + 4); - /* call the regular IRQ handler */ - handler(); - sw_int_num = 0; - return; - } - - if (desched && !current_task->events) { - /* - * Remove our own ready bit (current - tasks is same as - * task_get_current()) - */ - tasks_ready &= ~(1 << (current_task - tasks)); - } - tasks_ready |= 1 << resched; - - /* trigger a re-scheduling on exit */ - need_resched = 1; - -#ifdef CONFIG_TASK_PROFILING - svc_calls++; -#endif - /* adjust IPC to return *after* the syscall instruction */ - set_mepc(get_mepc() + 4); -} - -task_ * __ram_code next_sched_task(void) -{ - task_ *new_task = __task_id_to_ptr(__fls(tasks_ready & tasks_enabled)); - -#ifdef CONFIG_TASK_PROFILING - if (current_task != new_task) { - current_task->runtime += - (exc_start_time - exc_end_time - exc_sub_time); - task_will_switch = 1; - } -#endif - -#ifdef CONFIG_DEBUG_STACK_OVERFLOW - if (*current_task->stack != STACK_UNUSED_VALUE) { - int i = task_get_current(); - - panic_printf("\n\nStack overflow in %s task!\n", task_names[i]); -#ifdef CONFIG_SOFTWARE_PANIC - software_panic(PANIC_SW_STACK_OVERFLOW, i); -#endif - } -#endif - - return new_task; -} - -static inline void __schedule(int desched, int resched, int swirq) -{ - register int p0 asm("a0") = desched; - register int p1 asm("a1") = resched; - register int p2 asm("a2") = swirq; - - asm("ecall" : : "r"(p0), "r"(p1), "r"(p2)); -} - -void __ram_code update_exc_start_time(void) -{ -#ifdef CONFIG_TASK_PROFILING - exc_start_time = get_time().le.lo; -#endif -} - -/** - * The beginning of interrupt handler of c language code. - * - * @param none - * @return -1 if it cannot find the corresponding interrupt source. - */ -int __ram_code start_irq_handler(void) -{ - /* If this is a SW interrupt */ - if (get_mcause() == 11) { - ec_int = sw_int_num; - ec_int_group = 16; - } else { - /* - * Determine interrupt number. - * -1 if it cannot find the corresponding interrupt source. - */ - if (chip_get_ec_int() == -1) - return -1; - ec_int_group = chip_get_intc_group(ec_int); - } - -#if defined(CONFIG_LOW_POWER_IDLE) && defined(CHIP_FAMILY_IT83XX) - clock_sleep_mode_wakeup_isr(); -#endif -#ifdef CONFIG_TASK_PROFILING - update_exc_start_time(); - - /* - * Track IRQ distribution. No need for atomic add, because an IRQ - * can't pre-empt itself. - */ - if ((ec_int > 0) && (ec_int < ARRAY_SIZE(irq_dist))) - irq_dist[ec_int]++; -#endif - - return EC_SUCCESS; -} - -void __ram_code end_irq_handler(void) -{ -#ifdef CONFIG_TASK_PROFILING - uint32_t t, p; - - t = get_time().le.lo; - p = t - exc_start_time; - - exc_total_time += p; - exc_sub_time += p; - if (task_will_switch) { - task_will_switch = 0; - exc_sub_time = 0; - exc_end_time = t; - task_switches++; - } -#endif -} - -static uint32_t __ram_code __wait_evt(int timeout_us, task_id_t resched) -{ - task_ *tsk = current_task; - task_id_t me = tsk - tasks; - uint32_t evt; - int ret; - - ASSERT(!in_interrupt_context()); - - if (timeout_us > 0) { - timestamp_t deadline = get_time(); - - deadline.val += timeout_us; - ret = timer_arm(deadline, me); - ASSERT(ret == EC_SUCCESS); - } - while (!(evt = atomic_clear(&tsk->events))) { - /* Remove ourself and get the next task in the scheduler */ - __schedule(1, resched, 0); - resched = TASK_ID_IDLE; - } - if (timeout_us > 0) { - timer_cancel(me); - /* Ensure timer event is clear, we no longer care about it */ - atomic_clear_bits(&tsk->events, TASK_EVENT_TIMER); - } - return evt; -} - -uint32_t __ram_code task_set_event(task_id_t tskid, uint32_t event) -{ - task_ *receiver = __task_id_to_ptr(tskid); - - ASSERT(receiver); - - /* Set the event bit in the receiver message bitmap */ - atomic_or(&receiver->events, event); - - /* Re-schedule if priorities have changed */ - if (in_interrupt_context()) { - /* The receiver might run again */ - atomic_or(&tasks_ready, 1 << tskid); - if (start_called) - need_resched = 1; - } else { - __schedule(0, tskid, 0); - } - - return 0; -} - -uint32_t __ram_code task_wait_event(int timeout_us) -{ - return __wait_evt(timeout_us, TASK_ID_IDLE); -} - -uint32_t __ram_code task_wait_event_mask(uint32_t event_mask, int timeout_us) -{ - uint64_t deadline = get_time().val + timeout_us; - uint32_t events = 0; - int time_remaining_us = timeout_us; - - /* Add the timer event to the mask so we can indicate a timeout */ - event_mask |= TASK_EVENT_TIMER; - - while (!(events & event_mask)) { - /* Collect events to re-post later */ - events |= __wait_evt(time_remaining_us, TASK_ID_IDLE); - - time_remaining_us = deadline - get_time().val; - if (timeout_us > 0 && time_remaining_us <= 0) { - /* Ensure we return a TIMER event if we timeout */ - events |= TASK_EVENT_TIMER; - break; - } - } - - /* Re-post any other events collected */ - if (events & ~event_mask) - atomic_or(¤t_task->events, events & ~event_mask); - - return events & event_mask; -} - -uint32_t __ram_code read_clear_int_mask(void) -{ - uint32_t mie, meie = BIT(11); - - /* Read and clear MEIE bit of MIE register. */ - asm volatile ("csrrc %0, mie, %1" : "=r"(mie) : "r"(meie)); - - return mie; -} - -void __ram_code set_int_mask(uint32_t val) -{ - asm volatile ("csrw mie, %0" : : "r"(val)); -} - -void task_enable_all_tasks(void) -{ - /* Mark all tasks as ready and able to run. */ - tasks_ready = tasks_enabled = BIT(TASK_ID_COUNT) - 1; - /* Reschedule the highest priority task. */ - __schedule(0, 0, 0); -} - -void task_enable_task(task_id_t tskid) -{ - atomic_or(&tasks_enabled, BIT(tskid)); -} - -void task_disable_task(task_id_t tskid) -{ - atomic_clear_bits(&tasks_enabled, BIT(tskid)); - - if (!in_interrupt_context() && tskid == task_get_current()) - __schedule(0, 0, 0); -} - -void __ram_code task_enable_irq(int irq) -{ - uint32_t int_mask = read_clear_int_mask(); - - chip_enable_irq(irq); - set_int_mask(int_mask); -} - -void __ram_code task_disable_irq(int irq) -{ - uint32_t int_mask = read_clear_int_mask(); - - chip_disable_irq(irq); - set_int_mask(int_mask); -} - -void __ram_code task_clear_pending_irq(int irq) -{ - chip_clear_pending_irq(irq); -} - -void __ram_code task_trigger_irq(int irq) -{ - int cpu_int = chip_trigger_irq(irq); - - if (cpu_int > 0) { - sw_int_num = irq; - __schedule(0, 0, cpu_int); - } -} - -/* - * Initialize IRQs in the IVIC and set their priorities as defined by the - * DECLARE_IRQ statements. - */ -static void ivic_init_irqs(void) -{ - /* chip-specific interrupt controller initialization */ - chip_init_irqs(); - /* - * Re-enable global interrupts in case they're disabled. On a reboot, - * they're already enabled; if we've jumped here from another image, - * they're not. - */ - interrupt_enable(); -} - -void __ram_code mutex_lock(struct mutex *mtx) -{ - uint32_t locked; - uint32_t id = 1 << task_get_current(); - - ASSERT(id != TASK_ID_INVALID); - atomic_or(&mtx->waiters, id); - - while (1) { - asm volatile ( - /* set lock value */ - "li %0, 2\n\t" - /* attempt to acquire lock */ - "amoswap.w.aq %0, %0, %1\n\t" - : "=&r" (locked), "+A" (mtx->lock)); - /* we got it ! */ - if (!locked) - break; - /* Contention on the mutex */ - /* Sleep waiting for our turn */ - task_wait_event_mask(TASK_EVENT_MUTEX, 0); - } - - atomic_clear_bits(&mtx->waiters, id); -} - -void __ram_code mutex_unlock(struct mutex *mtx) -{ - uint32_t waiters; - task_ *tsk = current_task; - - /* give back the lock */ - asm volatile ( - "amoswap.w.aqrl zero, zero, %0\n\t" - : "+A" (mtx->lock)); - waiters = mtx->waiters; - - while (waiters) { - task_id_t id = __fls(waiters); - - waiters &= ~BIT(id); - - /* Somebody is waiting on the mutex */ - task_set_event(id, TASK_EVENT_MUTEX); - } - - /* Ensure no event is remaining from mutex wake-up */ - atomic_clear_bits(&tsk->events, TASK_EVENT_MUTEX); -} - -void task_print_list(void) -{ - int i; - - ccputs("Task Ready Name Events Time (s) StkUsed\n"); - - for (i = 0; i < TASK_ID_COUNT; i++) { - char is_ready = (tasks_ready & (1<<i)) ? 'R' : ' '; - uint32_t *sp; - - int stackused = tasks_init[i].stack_size; - - for (sp = tasks[i].stack; - sp < (uint32_t *)tasks[i].sp && *sp == STACK_UNUSED_VALUE; - sp++) - stackused -= sizeof(uint32_t); - - ccprintf("%4d %c %-16s %08x %11.6lld %3d/%3d\n", i, is_ready, - task_names[i], tasks[i].events, tasks[i].runtime, - stackused, tasks_init[i].stack_size); - cflush(); - } -} - -int command_task_info(int argc, char **argv) -{ -#ifdef CONFIG_TASK_PROFILING - unsigned int total = 0; - int i; -#endif - - task_print_list(); - -#ifdef CONFIG_TASK_PROFILING - ccputs("IRQ counts by type:\n"); - cflush(); - for (i = 0; i < ARRAY_SIZE(irq_dist); i++) { - if (irq_dist[i]) { - ccprintf("%4d %8d\n", i, irq_dist[i]); - total += irq_dist[i]; - } - } - - ccprintf("Service calls: %11u\n", svc_calls); - ccprintf("Total exceptions: %11u\n", total + svc_calls); - ccprintf("Task switches: %11u\n", task_switches); - ccprintf("Task switching started: %11.6llu s\n", task_start_time); - ccprintf("Time in tasks: %11.6llu s\n", - get_time().val - task_start_time); - ccprintf("Time in exceptions: %11.6llu s\n", exc_total_time); -#endif - - return EC_SUCCESS; -} -DECLARE_CONSOLE_COMMAND(taskinfo, command_task_info, - NULL, - "Print task info"); - -static int command_task_ready(int argc, char **argv) -{ - if (argc < 2) { - ccprintf("tasks_ready: 0x%08x\n", tasks_ready); - } else { - tasks_ready = strtoi(argv[1], NULL, 16); - ccprintf("Setting tasks_ready to 0x%08x\n", tasks_ready); - __schedule(0, 0, 0); - } - - return EC_SUCCESS; -} -DECLARE_CONSOLE_COMMAND(taskready, command_task_ready, - "[setmask]", - "Print/set ready tasks"); - -void task_pre_init(void) -{ - uint32_t *stack_next = (uint32_t *)task_stacks; - int i; - - /* Fill the task memory with initial values */ - for (i = 0; i < TASK_ID_COUNT; i++) { - uint32_t *sp; - /* Stack size in words */ - uint32_t ssize = tasks_init[i].stack_size / 4; - - tasks[i].stack = stack_next; - - /* - * Update stack used by first frame: 28 regs + MEPC + (FP regs) - */ - sp = stack_next + ssize - TASK_SCRATCHPAD_SIZE; - tasks[i].sp = (uint32_t)sp; - - /* Initial context on stack (see __switchto()) */ - sp[TASK_SCRATCHPAD_SIZE-2] = tasks_init[i].a0; /* a0 */ - sp[TASK_SCRATCHPAD_SIZE-1] = (uint32_t)task_exit_trap; /* ra */ - sp[0] = tasks_init[i].pc; /* pc/mepc */ - - /* Fill unused stack; also used to detect stack overflow. */ - for (sp = stack_next; sp < (uint32_t *)tasks[i].sp; sp++) - *sp = STACK_UNUSED_VALUE; - - stack_next += ssize; - } - - /* - * Fill in guard value in scratchpad to prevent stack overflow - * detection failure on the first context switch. This works because - * the first word in the scratchpad is where the switcher will store - * sp, so it's ok to blow away. - */ - ((task_ *)scratchpad)->stack = (uint32_t *)scratchpad; - *(uint32_t *)scratchpad = STACK_UNUSED_VALUE; - - /* Initialize IRQs */ - ivic_init_irqs(); -} - -int task_start(void) -{ -#ifdef CONFIG_TASK_PROFILING - task_start_time = get_time().val; - exc_end_time = get_time().le.lo; -#endif - - return __task_start(); -} |