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author | royger <royger@FreeBSD.org> | 2014-10-22 16:57:11 +0000 |
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committer | royger <royger@FreeBSD.org> | 2014-10-22 16:57:11 +0000 |
commit | 4d53ee84fafa57a4faed008e018563a5523aa008 (patch) | |
tree | b395b899cb2b694aea4e78a439efd5d4e1181a41 /sys/xen | |
parent | bca209134926c87ca1b88036757b0670f60d16ca (diff) | |
download | FreeBSD-src-4d53ee84fafa57a4faed008e018563a5523aa008.zip FreeBSD-src-4d53ee84fafa57a4faed008e018563a5523aa008.tar.gz |
xen: import a proper event channel user-space device
The user-space event channel device is used by applications to receive
and send event channel interrupts. This device is based on the Linux
evtchn device.
Sponsored by: Citrix Systems R&D
xen/evtchn/evtchn_dev.c:
- Remove the old event channel device, which was already disabled in
the build system.
dev/xen/evtchn/evtchn_dev.c:
- Import a new event channel device based on the one present in
Linux.
- This device allows the following operations:
- Bind VIRQ event channels (ioctl).
- Bind regular event channels (ioctl).
- Create and bind new event channels (ioctl).
- Unbind event channels (ioctl).
- Send notifications to event channels (ioctl).
- Reset the device shared memory ring (ioctl).
- Unmask event channels (write).
- Receive event channel upcalls (read).
- The new code is MP safe, and can be used concurrently.
conf/files:
- Add the new device to the build system.
Diffstat (limited to 'sys/xen')
-rw-r--r-- | sys/xen/evtchn/evtchn_dev.c | 358 |
1 files changed, 0 insertions, 358 deletions
diff --git a/sys/xen/evtchn/evtchn_dev.c b/sys/xen/evtchn/evtchn_dev.c deleted file mode 100644 index 9da2642..0000000 --- a/sys/xen/evtchn/evtchn_dev.c +++ /dev/null @@ -1,358 +0,0 @@ -/****************************************************************************** - * evtchn.c - * - * Xenolinux driver for receiving and demuxing event-channel signals. - * - * Copyright (c) 2004, K A Fraser - */ - -#include <sys/cdefs.h> -__FBSDID("$FreeBSD$"); - -#include <sys/param.h> -#include <sys/systm.h> -#include <sys/uio.h> -#include <sys/bus.h> -#include <sys/malloc.h> -#include <sys/kernel.h> -#include <sys/lock.h> -#include <sys/mutex.h> -#include <sys/selinfo.h> -#include <sys/poll.h> -#include <sys/conf.h> -#include <sys/fcntl.h> -#include <sys/ioccom.h> -#include <sys/rman.h> - -#include <xen/xen-os.h> -#include <xen/evtchn.h> -#include <xen/xen_intr.h> - -#include <machine/bus.h> -#include <machine/resource.h> -#include <machine/xen/synch_bitops.h> - -#include <xen/evtchn/evtchnvar.h> - -typedef struct evtchn_sotfc { - - struct selinfo ev_rsel; -} evtchn_softc_t; - -/* Only one process may open /dev/xen/evtchn at any time. */ -static unsigned long evtchn_dev_inuse; - -/* Notification ring, accessed via /dev/xen/evtchn. */ - -#define EVTCHN_RING_SIZE 2048 /* 2048 16-bit entries */ - -#define EVTCHN_RING_MASK(_i) ((_i)&(EVTCHN_RING_SIZE-1)) -static uint16_t *ring; -static unsigned int ring_cons, ring_prod, ring_overflow; - -/* Which ports is user-space bound to? */ -static uint32_t bound_ports[32]; - -/* Unique address for processes to sleep on */ -static void *evtchn_waddr = ˚ - -static struct mtx lock, upcall_lock; - -static d_read_t evtchn_read; -static d_write_t evtchn_write; -static d_ioctl_t evtchn_ioctl; -static d_poll_t evtchn_poll; -static d_open_t evtchn_open; -static d_close_t evtchn_close; - - -void -evtchn_device_upcall(evtchn_port_t port) -{ - mtx_lock(&upcall_lock); - - evtchn_mask_port(port); - evtchn_clear_port(port); - - if ( ring != NULL ) { - if ( (ring_prod - ring_cons) < EVTCHN_RING_SIZE ) { - ring[EVTCHN_RING_MASK(ring_prod)] = (uint16_t)port; - if ( ring_cons == ring_prod++ ) { - wakeup(evtchn_waddr); - } - } - else { - ring_overflow = 1; - } - } - - mtx_unlock(&upcall_lock); -} - -static void -__evtchn_reset_buffer_ring(void) -{ - /* Initialise the ring to empty. Clear errors. */ - ring_cons = ring_prod = ring_overflow = 0; -} - -static int -evtchn_read(struct cdev *dev, struct uio *uio, int ioflag) -{ - int rc; - unsigned int count, c, p, sst = 0, bytes1 = 0, bytes2 = 0; - count = uio->uio_resid; - - count &= ~1; /* even number of bytes */ - - if ( count == 0 ) - { - rc = 0; - goto out; - } - - if ( count > PAGE_SIZE ) - count = PAGE_SIZE; - - for ( ; ; ) { - if ( (c = ring_cons) != (p = ring_prod) ) - break; - - if ( ring_overflow ) { - rc = EFBIG; - goto out; - } - - if (sst != 0) { - rc = EINTR; - goto out; - } - - /* PCATCH == check for signals before and after sleeping - * PWAIT == priority of waiting on resource - */ - sst = tsleep(evtchn_waddr, PWAIT|PCATCH, "evchwt", 10); - } - - /* Byte lengths of two chunks. Chunk split (if any) is at ring wrap. */ - if ( ((c ^ p) & EVTCHN_RING_SIZE) != 0 ) { - bytes1 = (EVTCHN_RING_SIZE - EVTCHN_RING_MASK(c)) * sizeof(uint16_t); - bytes2 = EVTCHN_RING_MASK(p) * sizeof(uint16_t); - } - else { - bytes1 = (p - c) * sizeof(uint16_t); - bytes2 = 0; - } - - /* Truncate chunks according to caller's maximum byte count. */ - if ( bytes1 > count ) { - bytes1 = count; - bytes2 = 0; - } - else if ( (bytes1 + bytes2) > count ) { - bytes2 = count - bytes1; - } - - if ( uiomove(&ring[EVTCHN_RING_MASK(c)], bytes1, uio) || - ((bytes2 != 0) && uiomove(&ring[0], bytes2, uio))) - /* keeping this around as its replacement is not equivalent - * copyout(&ring[0], &buf[bytes1], bytes2) - */ - { - rc = EFAULT; - goto out; - } - - ring_cons += (bytes1 + bytes2) / sizeof(uint16_t); - - rc = bytes1 + bytes2; - - out: - - return rc; -} - -static int -evtchn_write(struct cdev *dev, struct uio *uio, int ioflag) -{ - int rc, i, count; - - count = uio->uio_resid; - - uint16_t *kbuf = (uint16_t *)malloc(PAGE_SIZE, M_DEVBUF, M_WAITOK); - - - if ( kbuf == NULL ) - return ENOMEM; - - count &= ~1; /* even number of bytes */ - - if ( count == 0 ) { - rc = 0; - goto out; - } - - if ( count > PAGE_SIZE ) - count = PAGE_SIZE; - - if ( uiomove(kbuf, count, uio) != 0 ) { - rc = EFAULT; - goto out; - } - - mtx_lock_spin(&lock); - for ( i = 0; i < (count/2); i++ ) - if ( test_bit(kbuf[i], &bound_ports[0]) ) - evtchn_unmask_port(kbuf[i]); - mtx_unlock_spin(&lock); - - rc = count; - - out: - free(kbuf, M_DEVBUF); - return rc; -} - -static int -evtchn_ioctl(struct cdev *dev, unsigned long cmd, caddr_t arg, - int mode, struct thread *td __unused) -{ - int rc = 0; - -#ifdef NOTYET - mtx_lock_spin(&lock); - - switch ( cmd ) - { - case EVTCHN_RESET: - __evtchn_reset_buffer_ring(); - break; - case EVTCHN_BIND: - if ( !synch_test_and_set_bit((uintptr_t)arg, &bound_ports[0]) ) - unmask_evtchn((uintptr_t)arg); - else - rc = EINVAL; - break; - case EVTCHN_UNBIND: - if ( synch_test_and_clear_bit((uintptr_t)arg, &bound_ports[0]) ) - mask_evtchn((uintptr_t)arg); - else - rc = EINVAL; - break; - default: - rc = ENOSYS; - break; - } - - mtx_unlock_spin(&lock); -#endif - - return rc; -} - -static int -evtchn_poll(struct cdev *dev, int poll_events, struct thread *td) -{ - - evtchn_softc_t *sc; - unsigned int mask = POLLOUT | POLLWRNORM; - - sc = dev->si_drv1; - - if ( ring_cons != ring_prod ) - mask |= POLLIN | POLLRDNORM; - else if ( ring_overflow ) - mask = POLLERR; - else - selrecord(td, &sc->ev_rsel); - - - return mask; -} - - -static int -evtchn_open(struct cdev *dev, int flag, int otyp, struct thread *td) -{ - uint16_t *_ring; - - if (flag & O_NONBLOCK) - return EBUSY; - - if ( synch_test_and_set_bit(0, &evtchn_dev_inuse) ) - return EBUSY; - - if ( (_ring = (uint16_t *)malloc(PAGE_SIZE, M_DEVBUF, M_WAITOK)) == NULL ) - return ENOMEM; - - mtx_lock_spin(&lock); - ring = _ring; - __evtchn_reset_buffer_ring(); - mtx_unlock_spin(&lock); - - - return 0; -} - -static int -evtchn_close(struct cdev *dev, int flag, int otyp, struct thread *td __unused) -{ - int i; - - if (ring != NULL) { - free(ring, M_DEVBUF); - ring = NULL; - } - mtx_lock_spin(&lock); - for ( i = 0; i < NR_EVENT_CHANNELS; i++ ) - if ( synch_test_and_clear_bit(i, &bound_ports[0]) ) - evtchn_mask_port(i); - mtx_unlock_spin(&lock); - - evtchn_dev_inuse = 0; - - return 0; -} - -static struct cdevsw evtchn_devsw = { - .d_version = D_VERSION, - .d_open = evtchn_open, - .d_close = evtchn_close, - .d_read = evtchn_read, - .d_write = evtchn_write, - .d_ioctl = evtchn_ioctl, - .d_poll = evtchn_poll, - .d_name = "evtchn", -}; - - -/* XXX - if this device is ever supposed to support use by more than one process - * this global static will have to go away - */ -static struct cdev *evtchn_dev; - - - -static int -evtchn_dev_init(void *dummy __unused) -{ - /* XXX I believe we don't need these leaving them here for now until we - * have some semblance of it working - */ - mtx_init(&upcall_lock, "evtchup", NULL, MTX_DEF); - - /* (DEVFS) create '/dev/misc/evtchn'. */ - evtchn_dev = make_dev(&evtchn_devsw, 0, UID_ROOT, GID_WHEEL, 0600, "xen/evtchn"); - - mtx_init(&lock, "evch", NULL, MTX_SPIN | MTX_NOWITNESS); - - evtchn_dev->si_drv1 = malloc(sizeof(evtchn_softc_t), M_DEVBUF, M_WAITOK); - bzero(evtchn_dev->si_drv1, sizeof(evtchn_softc_t)); - - if (bootverbose) - printf("Event-channel device installed.\n"); - - return 0; -} - -SYSINIT(evtchn_dev_init, SI_SUB_DRIVERS, SI_ORDER_FIRST, evtchn_dev_init, NULL); |