diff options
Diffstat (limited to 'arch/um/kernel/irq_user.c')
| -rw-r--r-- | arch/um/kernel/irq_user.c | 443 |
1 files changed, 443 insertions, 0 deletions
diff --git a/arch/um/kernel/irq_user.c b/arch/um/kernel/irq_user.c new file mode 100644 index 000000000000..6d6f9484b884 --- /dev/null +++ b/arch/um/kernel/irq_user.c @@ -0,0 +1,443 @@ +/* + * Copyright (C) 2000 Jeff Dike (jdike@karaya.com) + * Licensed under the GPL + */ + +#include <stdlib.h> +#include <unistd.h> +#include <errno.h> +#include <signal.h> +#include <string.h> +#include <sys/poll.h> +#include <sys/types.h> +#include <sys/time.h> +#include "user_util.h" +#include "kern_util.h" +#include "user.h" +#include "process.h" +#include "signal_user.h" +#include "sigio.h" +#include "irq_user.h" +#include "os.h" + +struct irq_fd { + struct irq_fd *next; + void *id; + int fd; + int type; + int irq; + int pid; + int events; + int current_events; + int freed; +}; + +static struct irq_fd *active_fds = NULL; +static struct irq_fd **last_irq_ptr = &active_fds; + +static struct pollfd *pollfds = NULL; +static int pollfds_num = 0; +static int pollfds_size = 0; + +extern int io_count, intr_count; + +void sigio_handler(int sig, union uml_pt_regs *regs) +{ + struct irq_fd *irq_fd, *next; + int i, n; + + if(smp_sigio_handler()) return; + while(1){ + n = poll(pollfds, pollfds_num, 0); + if(n < 0){ + if(errno == EINTR) continue; + printk("sigio_handler : poll returned %d, " + "errno = %d\n", n, errno); + break; + } + if(n == 0) break; + + irq_fd = active_fds; + for(i = 0; i < pollfds_num; i++){ + if(pollfds[i].revents != 0){ + irq_fd->current_events = pollfds[i].revents; + pollfds[i].fd = -1; + } + irq_fd = irq_fd->next; + } + + for(irq_fd = active_fds; irq_fd != NULL; irq_fd = next){ + next = irq_fd->next; + if(irq_fd->current_events != 0){ + irq_fd->current_events = 0; + do_IRQ(irq_fd->irq, regs); + + /* This is here because the next irq may be + * freed in the handler. If a console goes + * away, both the read and write irqs will be + * freed. After do_IRQ, ->next will point to + * a good IRQ. + * Irqs can't be freed inside their handlers, + * so the next best thing is to have them + * marked as needing freeing, so that they + * can be freed here. + */ + next = irq_fd->next; + if(irq_fd->freed){ + free_irq(irq_fd->irq, irq_fd->id); + free_irq_by_irq_and_dev(irq_fd->irq, + irq_fd->id); + } + } + } + } +} + +int activate_ipi(int fd, int pid) +{ + return(os_set_fd_async(fd, pid)); +} + +static void maybe_sigio_broken(int fd, int type) +{ + if(isatty(fd)){ + if((type == IRQ_WRITE) && !pty_output_sigio){ + write_sigio_workaround(); + add_sigio_fd(fd, 0); + } + else if((type == IRQ_READ) && !pty_close_sigio){ + write_sigio_workaround(); + add_sigio_fd(fd, 1); + } + } +} + +int activate_fd(int irq, int fd, int type, void *dev_id) +{ + struct pollfd *tmp_pfd; + struct irq_fd *new_fd, *irq_fd; + unsigned long flags; + int pid, events, err, n, size; + + pid = os_getpid(); + err = os_set_fd_async(fd, pid); + if(err < 0) + goto out; + + new_fd = um_kmalloc(sizeof(*new_fd)); + err = -ENOMEM; + if(new_fd == NULL) + goto out; + + if(type == IRQ_READ) events = POLLIN | POLLPRI; + else events = POLLOUT; + *new_fd = ((struct irq_fd) { .next = NULL, + .id = dev_id, + .fd = fd, + .type = type, + .irq = irq, + .pid = pid, + .events = events, + .current_events = 0, + .freed = 0 } ); + + /* Critical section - locked by a spinlock because this stuff can + * be changed from interrupt handlers. The stuff above is done + * outside the lock because it allocates memory. + */ + + /* Actually, it only looks like it can be called from interrupt + * context. The culprit is reactivate_fd, which calls + * maybe_sigio_broken, which calls write_sigio_workaround, + * which calls activate_fd. However, write_sigio_workaround should + * only be called once, at boot time. That would make it clear that + * this is called only from process context, and can be locked with + * a semaphore. + */ + flags = irq_lock(); + for(irq_fd = active_fds; irq_fd != NULL; irq_fd = irq_fd->next){ + if((irq_fd->fd == fd) && (irq_fd->type == type)){ + printk("Registering fd %d twice\n", fd); + printk("Irqs : %d, %d\n", irq_fd->irq, irq); + printk("Ids : 0x%x, 0x%x\n", irq_fd->id, dev_id); + goto out_unlock; + } + } + + n = pollfds_num; + if(n == pollfds_size){ + while(1){ + /* Here we have to drop the lock in order to call + * kmalloc, which might sleep. If something else + * came in and changed the pollfds array, we free + * the buffer and try again. + */ + irq_unlock(flags); + size = (pollfds_num + 1) * sizeof(pollfds[0]); + tmp_pfd = um_kmalloc(size); + flags = irq_lock(); + if(tmp_pfd == NULL) + goto out_unlock; + if(n == pollfds_size) + break; + kfree(tmp_pfd); + } + if(pollfds != NULL){ + memcpy(tmp_pfd, pollfds, + sizeof(pollfds[0]) * pollfds_size); + kfree(pollfds); + } + pollfds = tmp_pfd; + pollfds_size++; + } + + if(type == IRQ_WRITE) + fd = -1; + + pollfds[pollfds_num] = ((struct pollfd) { .fd = fd, + .events = events, + .revents = 0 }); + pollfds_num++; + + *last_irq_ptr = new_fd; + last_irq_ptr = &new_fd->next; + + irq_unlock(flags); + + /* This calls activate_fd, so it has to be outside the critical + * section. + */ + maybe_sigio_broken(fd, type); + + return(0); + + out_unlock: + irq_unlock(flags); + kfree(new_fd); + out: + return(err); +} + +static void free_irq_by_cb(int (*test)(struct irq_fd *, void *), void *arg) +{ + struct irq_fd **prev; + unsigned long flags; + int i = 0; + + flags = irq_lock(); + prev = &active_fds; + while(*prev != NULL){ + if((*test)(*prev, arg)){ + struct irq_fd *old_fd = *prev; + if((pollfds[i].fd != -1) && + (pollfds[i].fd != (*prev)->fd)){ + printk("free_irq_by_cb - mismatch between " + "active_fds and pollfds, fd %d vs %d\n", + (*prev)->fd, pollfds[i].fd); + goto out; + } + memcpy(&pollfds[i], &pollfds[i + 1], + (pollfds_num - i - 1) * sizeof(pollfds[0])); + pollfds_num--; + if(last_irq_ptr == &old_fd->next) + last_irq_ptr = prev; + *prev = (*prev)->next; + if(old_fd->type == IRQ_WRITE) + ignore_sigio_fd(old_fd->fd); + kfree(old_fd); + continue; + } + prev = &(*prev)->next; + i++; + } + out: + irq_unlock(flags); +} + +struct irq_and_dev { + int irq; + void *dev; +}; + +static int same_irq_and_dev(struct irq_fd *irq, void *d) +{ + struct irq_and_dev *data = d; + + return((irq->irq == data->irq) && (irq->id == data->dev)); +} + +void free_irq_by_irq_and_dev(unsigned int irq, void *dev) +{ + struct irq_and_dev data = ((struct irq_and_dev) { .irq = irq, + .dev = dev }); + + free_irq_by_cb(same_irq_and_dev, &data); +} + +static int same_fd(struct irq_fd *irq, void *fd) +{ + return(irq->fd == *((int *) fd)); +} + +void free_irq_by_fd(int fd) +{ + free_irq_by_cb(same_fd, &fd); +} + +static struct irq_fd *find_irq_by_fd(int fd, int irqnum, int *index_out) +{ + struct irq_fd *irq; + int i = 0; + + for(irq=active_fds; irq != NULL; irq = irq->next){ + if((irq->fd == fd) && (irq->irq == irqnum)) break; + i++; + } + if(irq == NULL){ + printk("find_irq_by_fd doesn't have descriptor %d\n", fd); + goto out; + } + if((pollfds[i].fd != -1) && (pollfds[i].fd != fd)){ + printk("find_irq_by_fd - mismatch between active_fds and " + "pollfds, fd %d vs %d, need %d\n", irq->fd, + pollfds[i].fd, fd); + irq = NULL; + goto out; + } + *index_out = i; + out: + return(irq); +} + +void free_irq_later(int irq, void *dev_id) +{ + struct irq_fd *irq_fd; + unsigned long flags; + + flags = irq_lock(); + for(irq_fd = active_fds; irq_fd != NULL; irq_fd = irq_fd->next){ + if((irq_fd->irq == irq) && (irq_fd->id == dev_id)) + break; + } + if(irq_fd == NULL){ + printk("free_irq_later found no irq, irq = %d, " + "dev_id = 0x%p\n", irq, dev_id); + goto out; + } + irq_fd->freed = 1; + out: + irq_unlock(flags); +} + +void reactivate_fd(int fd, int irqnum) +{ + struct irq_fd *irq; + unsigned long flags; + int i; + + flags = irq_lock(); + irq = find_irq_by_fd(fd, irqnum, &i); + if(irq == NULL){ + irq_unlock(flags); + return; + } + + pollfds[i].fd = irq->fd; + + irq_unlock(flags); + + /* This calls activate_fd, so it has to be outside the critical + * section. + */ + maybe_sigio_broken(fd, irq->type); +} + +void deactivate_fd(int fd, int irqnum) +{ + struct irq_fd *irq; + unsigned long flags; + int i; + + flags = irq_lock(); + irq = find_irq_by_fd(fd, irqnum, &i); + if(irq == NULL) + goto out; + pollfds[i].fd = -1; + out: + irq_unlock(flags); +} + +int deactivate_all_fds(void) +{ + struct irq_fd *irq; + int err; + + for(irq=active_fds;irq != NULL;irq = irq->next){ + err = os_clear_fd_async(irq->fd); + if(err) + return(err); + } + /* If there is a signal already queued, after unblocking ignore it */ + set_handler(SIGIO, SIG_IGN, 0, -1); + + return(0); +} + +void forward_ipi(int fd, int pid) +{ + int err; + + err = os_set_owner(fd, pid); + if(err < 0) + printk("forward_ipi: set_owner failed, fd = %d, me = %d, " + "target = %d, err = %d\n", fd, os_getpid(), pid, -err); +} + +void forward_interrupts(int pid) +{ + struct irq_fd *irq; + unsigned long flags; + int err; + + flags = irq_lock(); + for(irq=active_fds;irq != NULL;irq = irq->next){ + err = os_set_owner(irq->fd, pid); + if(err < 0){ + /* XXX Just remove the irq rather than + * print out an infinite stream of these + */ + printk("Failed to forward %d to pid %d, err = %d\n", + irq->fd, pid, -err); + } + + irq->pid = pid; + } + irq_unlock(flags); +} + +void init_irq_signals(int on_sigstack) +{ + __sighandler_t h; + int flags; + + flags = on_sigstack ? SA_ONSTACK : 0; + if(timer_irq_inited) h = (__sighandler_t) alarm_handler; + else h = boot_timer_handler; + + set_handler(SIGVTALRM, h, flags | SA_RESTART, + SIGUSR1, SIGIO, SIGWINCH, SIGALRM, -1); + set_handler(SIGIO, (__sighandler_t) sig_handler, flags | SA_RESTART, + SIGUSR1, SIGIO, SIGWINCH, SIGALRM, SIGVTALRM, -1); + signal(SIGWINCH, SIG_IGN); +} + +/* + * Overrides for Emacs so that we follow Linus's tabbing style. + * Emacs will notice this stuff at the end of the file and automatically + * adjust the settings for this buffer only. This must remain at the end + * of the file. + * --------------------------------------------------------------------------- + * Local variables: + * c-file-style: "linux" + * End: + */ |