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:
+ */