/*
- * Copyright Droids Corporation
- * Olivier Matz <zer0@droids-corp.org>
+ * Copyright 2014 Olivier Matz <zer0@droids-corp.org>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
*/
#ifdef HOST_VERSION
+
/*
* AVR simulator. This code is used on host (PC for instance) to
* generate a signal that will call other aversive modules like
* hardware interrupts in a unix application.
*/
+/*
+ * To simulate AVR interruptions, we use signals. The signals are
+ * always allowed, and the handler is located in hostsim code. In the
+ * hostsim handler, we check if the IRQ are allowed (in this case we
+ * call the handler) or not (in this case we ignore the IRQ). Indeed,
+ * the sei() / cli() functions just set a flag located in hostsim.
+ *
+ * Note that a signal handler can be preempted by itself. It means
+ * that
+ */
+
#include <aversive.h>
#include <stdio.h>
#include <sys/time.h>
#include <sys/types.h>
#include <sys/wait.h>
+#include <sys/queue.h>
#include <termios.h>
+#include <signal.h>
#ifdef CONFIG_MODULE_SCHEDULER
#include <scheduler.h>
#include <uart_host.h>
#endif
-static pthread_mutex_t mut = PTHREAD_MUTEX_INITIALIZER;
-static volatile int cpt = 0;
+/* list of scheduled ittimers */
+LIST_HEAD(hostsim_ittimer_list, hostsim_ittimer);
+struct hostsim_ittimer_list tim_list = LIST_HEAD_INITIALIZER(&tim_list);
+
+/* structure describing an interruption timer */
+struct hostsim_ittimer {
+ LIST_ENTRY(hostsim_ittimer) next;
+ uint32_t period_ns;
+ uint64_t prev_tick;
+ unsigned pending;
+ void (*handler)(void);
+};
-static struct termios oldterm;
-/* static */ int old_stdin, old_stdout;
+/* tell if global emulated IRQ are locked (1) or allowed (0). The
+ * default IRQ state is locked as on a real avr */
+#define IRQ_LOCKED 0
+#define IRQ_ALLOWED 1
+static uint8_t irq_flags = IRQ_LOCKED;
+
+static int old_stdin, old_stdout;
static int stdin_pipe[2];
static int stdout_pipe[2];
-enum msg_type {
- SCHED,
- UART_RCV,
- UART_SND,
-};
+/* ring buffer to send from pthread to signal */
+#define RG_SIZE 256 /* pow of 2 */
+#define RG_MASK (RG_SIZE-1)
+volatile char out_buf[RG_SIZE];
+volatile unsigned out_tail = 0;
+volatile unsigned out_head = 0;
+pthread_t out_pthread;
+volatile char in_buf[RG_SIZE];
+volatile unsigned in_tail = 0;
+volatile unsigned in_head = 0;
+pthread_t in_pthread;
+
+/* store the previous state of termios, restored in hostsim_exit() */
+static struct termios oldterm;
-struct message {
- enum msg_type type;
- char c;
-};
-static struct message g_msg;
+void hostsim_sei(void)
+{
+ irq_flags = IRQ_ALLOWED;
+}
-#ifdef SA_SIGINFO
-static void sigusr1(__attribute__((unused)) int sig,
- __attribute__((unused)) siginfo_t *info,
- __attribute__((unused)) void *uc)
-#else
-void sigusr1(__attribute__((unused)) int sig)
-#endif
+void hostsim_cli(void)
{
- struct message m;
- m = g_msg;
+ irq_flags = IRQ_LOCKED;
+}
-#ifdef CONFIG_MODULE_SCHEDULER
- if (m.type == SCHED) {
- pthread_mutex_unlock(&mut);
- scheduler_interrupt();
+/* lock emulated IRQ and return the previous state */
+uint8_t hostsim_irq_save(void)
+{
+ uint8_t old = irq_flags;
+ hostsim_cli();
+ return old;
+}
+
+/* returns a monotonic clock in nanoseconds */
+static inline uint64_t get_clk(void)
+{
+ struct timespec ts;
+ uint64_t t;
+
+ if (clock_gettime(CLOCK_MONOTONIC_RAW, &ts) < 0) {
+ printf("clock_getres() failed: %s\n", strerror(errno));
+ exit(1);
}
-#endif
+ t = ts.tv_sec;
+ t *= 1000000000;
+ t += ts.tv_nsec;
+ return t;
+}
-#ifdef CONFIG_MODULE_UART
- if (m.type == UART_RCV) {
- uart_host_rx_event(m.c);
- pthread_mutex_unlock(&mut);
+static void handle_interrupts(void)
+{
+ struct hostsim_ittimer *tim;
+ uint64_t clk;
+ uint64_t cur, next;
+ int c;
+ unsigned head;
+
+ clk = get_clk();
+
+ /* do the uart events if data is available */
+ if (irq_flags == IRQ_ALLOWED) {
+ while ((int)(out_tail - out_head) > 0) {
+ irq_flags = IRQ_LOCKED;
+ head = out_head;
+ c = out_buf[out_head & RG_MASK];
+ if (__sync_val_compare_and_swap(&out_head,
+ head, head + 1) != head)
+ continue;
+ uart_host_tx_event(c);
+ irq_flags = IRQ_ALLOWED;
+ }
+ while ((int)(in_tail - in_head) > 0) {
+ irq_flags = IRQ_LOCKED;
+ head = in_head;
+ c = in_buf[in_head & RG_MASK];
+ uart_host_rx_event(c);
+ if (__sync_val_compare_and_swap(&in_head,
+ head, head + 1) != head)
+ continue;
+ irq_flags = IRQ_ALLOWED;
+ }
}
- if (m.type == UART_SND) {
- uart_host_tx_event(m.c);
- pthread_mutex_unlock(&mut);
+
+ /* browse all timers */
+ LIST_FOREACH(tim, &tim_list, next) {
+
+ /* Call the handler if it's time to. We use an atomic operation
+ * because we can be interrupted by our own signal any moment */
+ do {
+ cur = tim->prev_tick;
+ next = tim->prev_tick + tim->period_ns;
+
+ if (next > clk)
+ break;
+
+ if (__sync_val_compare_and_swap(&tim->prev_tick,
+ cur, next) != cur)
+ continue;
+
+ /* if irq are disabled, just mark the timer as pending,
+ * it will be executed from hostsim_irq_restore(). We
+ * may loose interrupts if they stay locked too long,
+ * like on the real hw */
+ if (irq_flags == IRQ_LOCKED)
+ tim->pending = 1;
+ else {
+ irq_flags = IRQ_LOCKED;
+ tim->pending = 0;
+ tim->handler();
+ irq_flags = IRQ_ALLOWED;
+ }
+ } while (1);
+
+ /* also execute the irq if it was pending */
+ if (irq_flags == IRQ_ALLOWED && tim->pending == 1) {
+ irq_flags = IRQ_LOCKED;
+ tim->pending = 0;
+ tim->handler();
+ irq_flags = IRQ_ALLOWED;
+ }
}
-#endif
}
-static int lock_count = 0;
-
-void hostsim_lock(void)
+/* restore the state given as parameter */
+void hostsim_irq_restore(uint8_t flags)
{
- if (lock_count++)
+ /* on transition "locked" -> "unlocked", call any pending interrupts
+ * before releasing IRQ lock. For other transitions, just set the
+ * irq_flags variable */
+
+ if (irq_flags == IRQ_ALLOWED || flags == IRQ_LOCKED) {
+ irq_flags = flags;
return;
- pthread_mutex_lock(&mut);
-}
+ }
-void hostsim_unlock(void)
-{
- if (lock_count-- == 1)
- pthread_mutex_unlock(&mut);
+ irq_flags = IRQ_ALLOWED;
+ handle_interrupts();
}
-int hostsim_islocked(void)
+/* return 1 if emulated IRQ are locked */
+uint8_t hostsim_irq_locked(void)
{
- return lock_count;
+ return irq_flags == IRQ_LOCKED;
}
+/* replacement for wait_ms() */
void host_wait_ms(int ms)
{
struct timeval tv, tv2, diff;
}
}
+/* add a new timer: loaded at init and cannot be unloaded. */
+struct hostsim_ittimer *hostsim_ittimer_add(void (*handler)(void),
+ unsigned period_ns)
+{
+ struct hostsim_ittimer *tim;
+
+ tim = malloc(sizeof(*tim));
+ if (tim == NULL) {
+ printf("not enough memory: cannot allocate timer\n");
+ exit(1);
+ }
+
+ tim->period_ns = period_ns;
+ tim->prev_tick = get_clk();
+ tim->handler = handler;
+ LIST_INSERT_HEAD(&tim_list, tim, next);
+ return tim;
+}
-/* sends signal to child */
-void *parent(void *arg)
+/* the signal handler, preemptable by itself */
+#ifdef SA_SIGINFO
+static void sigtimer(__attribute__((unused)) int sig,
+ __attribute__((unused)) siginfo_t *info,
+ __attribute__((unused)) void *uc)
+#else
+ void sigtimer(__attribute__((unused)) int sig)
+#endif
{
- pthread_t thread = (pthread_t)arg;
- struct timeval cur_tv, prev_tv, tv_millisec;
- int n;
+ static int recurs = 0;
- gettimeofday(&prev_tv, NULL);
+ if (recurs > 10)
+ return;
+ recurs++;
+ handle_interrupts();
+ recurs--;
+}
- while (1) {
- usleep(1000);
- gettimeofday(&cur_tv, NULL);
-
- n = 0;
- while (timercmp(&prev_tv, &cur_tv, <)) {
- if (n > 5) {
- /* give some time between subsequent
- * signals */
- usleep(100);
- n = 0;
- }
- pthread_mutex_lock(&mut);
- g_msg.type = SCHED;
- pthread_kill(thread, SIGUSR1);
-
- /* signal was acked */
- tv_millisec.tv_sec = 0;
- tv_millisec.tv_usec = 1000;
- timeradd(&prev_tv, &tv_millisec, &prev_tv);
- n ++;
- }
+/* enable loaded ittimers */
+int hostsim_ittimer_enable(unsigned timer_resolution_us)
+{
+ struct sigaction sigact;
+ struct itimerval t;
+
+ /* register a signal handler, which is interruptible */
+ memset(&sigact, 0, sizeof(sigact));
+ sigemptyset(&sigact.sa_mask);
+ sigact.sa_flags |= SA_NODEFER;
+ sigact.sa_sigaction = sigtimer;
+ sigaction(SIGALRM, &sigact, NULL);
+
+ /* do not interrupt syscalls */
+ if (siginterrupt (SIGALRM, 0) != 0)
+ return -1;
+
+ memset(&t, 0, sizeof(t));
+ t.it_value.tv_usec = timer_resolution_us;
+ t.it_value.tv_sec = 0;
+ t.it_interval.tv_usec = timer_resolution_us;
+ t.it_interval.tv_sec = 0;
+
+ if (setitimer(ITIMER_REAL, &t, NULL) < 0) {
+ printf("setitimer failed\n");
+ return -1;
}
- pthread_exit(NULL);
- return NULL;
+ return 0;
}
void *hostsim_uart_stdin(void *arg)
{
- pthread_t thread = (pthread_t)arg;
int n;
char c;
+ static char prev_c;
+
+ (void)arg;
/* read on old stdin and put it in pipe */
while (1) {
+ if (in_tail - in_head >= (RG_SIZE - 1)) {
+ /* no more room, wait (should we drop ?) */
+ usleep(1000);
+ continue;
+ }
+
n = read(old_stdin, &c, 1);
if (n <= 0)
break;
- pthread_mutex_lock(&mut);
- g_msg.type = UART_RCV;
- g_msg.c = c;
- pthread_kill(thread, SIGUSR1);
+ if (prev_c == '\x01' /* ctrl-a */ && c == 'q')
+ hostsim_uart_exit();
+
+ prev_c = c;
+
+ in_buf[in_tail & RG_MASK] = c;
+ in_tail++;
write(stdin_pipe[1], &c, 1);
}
void *hostsim_uart_stdout(void *arg)
{
- pthread_t thread = (pthread_t)arg;
int n;
char c;
+ (void)arg;
+
/* read on our pipe, and forward it to the old stdout */
while (1) {
+ if (out_tail - out_head >= (RG_SIZE - 1)) {
+ /* no more room, wait (should we drop ?) */
+ usleep(1000);
+ continue;
+ }
+
n = read(stdout_pipe[0], &c, 1);
- if (n <= 0)
+ if (n <= 0) {
+ printf("read failed: %s\n", strerror(errno));
break;
+ }
- pthread_mutex_lock(&mut);
- g_msg.type = UART_SND;
- g_msg.c = c;
- pthread_kill(thread, SIGUSR1);
+ out_buf[out_tail & RG_MASK] = c;
+ out_tail++;
write(old_stdout, &c, 1);
}
return NULL;
}
+/* initialize hostsim framework for uart */
int hostsim_uart_init(void)
{
struct termios term;
+ int ret;
+
+ printf("hostsim/uart: type ctrl-a + q to exit\n");
tcgetattr(0, &oldterm);
memcpy(&term, &oldterm, sizeof(term));
term.c_lflag &= ~(ICANON | ECHO | ISIG);
tcsetattr(0, TCSANOW, &term);
+ setbuf(stdin, NULL);
+ setbuf(stdout, NULL);
+
/* duplicate stdin */
old_stdin = dup(0);
if (old_stdin < 0)
if (dup2(stdout_pipe[1], 1) < 0)
return -1;
close(stdout_pipe[1]);
- setbuf(stdin, NULL);
- setbuf(stdout, NULL);
-
- return 0;
-}
-
-int hostsim_init(void)
-{
- struct sigaction sigact;
- pthread_t parent_id, child_id, child2_id, child3_id;
- int ret;
-
- parent_id = pthread_self();
-
- pthread_mutex_lock(&mut);
- ret = pthread_create(&child_id, NULL, parent, (void *)parent_id);
- if (ret) {
- printf("pthread_create() returned %d\n", ret);
- pthread_mutex_unlock(&mut);
- return -1;
- }
-#ifdef CONFIG_MODULE_UART
- if (hostsim_uart_init())
- return -1;
-
- ret = pthread_create(&child2_id, NULL, hostsim_uart_stdin, (void *)parent_id);
+ ret = pthread_create(&in_pthread, NULL, hostsim_uart_stdin, NULL);
if (ret) {
printf("pthread_create() returned %d\n", ret);
- pthread_mutex_unlock(&mut);
return -1;
}
- ret = pthread_create(&child3_id, NULL, hostsim_uart_stdout, (void *)parent_id);
+ ret = pthread_create(&out_pthread, NULL, hostsim_uart_stdout, NULL);
if (ret) {
printf("pthread_create() returned %d\n", ret);
- pthread_mutex_unlock(&mut);
return -1;
}
-#endif
-
- /* register a signal handler, which is interruptible */
- memset(&sigact, 0, sizeof(sigact));
- sigemptyset(&sigact.sa_mask);
- sigact.sa_flags |= SA_NODEFER;
- sigact.sa_sigaction = sigusr1;
- sigaction(SIGUSR1, &sigact, NULL);
-
- /* */
- if (siginterrupt (SIGUSR1, 0) != 0)
- return -1;
-
- pthread_mutex_unlock(&mut);
return 0;
}
-int hostsim_exit(void)
+int hostsim_uart_exit(void)
{
-#ifdef CONFIG_MODULE_UART
- tcsetattr(0, TCSANOW, &oldterm);
-#endif
+ tcsetattr(old_stdin, TCSANOW, &oldterm);
exit(0);
return 0;
}
git.droids-corp.org / aversive.git / blobdiff