diff options
Diffstat (limited to 'sys/cam/scsi/scsi_sa.c')
| -rw-r--r-- | sys/cam/scsi/scsi_sa.c | 117 |
1 files changed, 113 insertions, 4 deletions
diff --git a/sys/cam/scsi/scsi_sa.c b/sys/cam/scsi/scsi_sa.c index f9b0872..6b941e0 100644 --- a/sys/cam/scsi/scsi_sa.c +++ b/sys/cam/scsi/scsi_sa.c @@ -43,6 +43,8 @@ __FBSDID("$FreeBSD$"); #include <sys/mtio.h> #ifdef _KERNEL #include <sys/conf.h> +#include <sys/sysctl.h> +#include <sys/taskqueue.h> #endif #include <sys/fcntl.h> #include <sys/devicestat.h> @@ -223,6 +225,8 @@ struct sa_softc { u_int32_t max_blk; u_int32_t min_blk; u_int32_t maxio; + u_int32_t cpi_maxio; + int allow_io_split; u_int32_t comp_algorithm; u_int32_t saved_comp_algorithm; u_int32_t media_blksize; @@ -268,6 +272,10 @@ struct sa_softc { open_rdonly : 1, /* open read-only */ open_pending_mount : 1, /* open pending mount */ ctrl_mode : 1; /* control device open */ + + struct task sysctl_task; + struct sysctl_ctx_list sysctl_ctx; + struct sysctl_oid *sysctl_tree; }; struct sa_quirk_entry { @@ -426,6 +434,22 @@ static int sardpos(struct cam_periph *periph, int, u_int32_t *); static int sasetpos(struct cam_periph *periph, int, u_int32_t *); +#ifndef SA_DEFAULT_IO_SPLIT +#define SA_DEFAULT_IO_SPLIT 0 +#endif + +static int sa_allow_io_split = SA_DEFAULT_IO_SPLIT; + +/* + * Tunable to allow the user to set a global allow_io_split value. Note + * that this WILL GO AWAY in FreeBSD 11.0. Silently splitting the I/O up + * is bad behavior, because it hides the true tape block size from the + * application. + */ +TUNABLE_INT("kern.cam.sa.allow_io_split", &sa_allow_io_split); +static SYSCTL_NODE(_kern_cam, OID_AUTO, sa, CTLFLAG_RD, 0, + "CAM Sequential Access Tape Driver"); + static struct periph_driver sadriver = { sainit, "sa", @@ -1448,6 +1472,49 @@ saasync(void *callback_arg, u_int32_t code, } } +static void +sasysctlinit(void *context, int pending) +{ + struct cam_periph *periph; + struct sa_softc *softc; + char tmpstr[80], tmpstr2[80]; + + periph = (struct cam_periph *)context; + /* + * If the periph is invalid, no need to setup the sysctls. + */ + if (periph->flags & CAM_PERIPH_INVALID) + goto bailout; + + softc = (struct sa_softc *)periph->softc; + + snprintf(tmpstr, sizeof(tmpstr), "CAM SA unit %d", periph->unit_number); + snprintf(tmpstr2, sizeof(tmpstr2), "%u", periph->unit_number); + + sysctl_ctx_init(&softc->sysctl_ctx); + softc->sysctl_tree = SYSCTL_ADD_NODE(&softc->sysctl_ctx, + SYSCTL_STATIC_CHILDREN(_kern_cam_sa), OID_AUTO, tmpstr2, + CTLFLAG_RD, 0, tmpstr); + if (softc->sysctl_tree == NULL) + goto bailout; + + SYSCTL_ADD_INT(&softc->sysctl_ctx, SYSCTL_CHILDREN(softc->sysctl_tree), + OID_AUTO, "allow_io_split", CTLTYPE_INT | CTLFLAG_RDTUN, + &softc->allow_io_split, 0, "Allow Splitting I/O"); + SYSCTL_ADD_INT(&softc->sysctl_ctx, SYSCTL_CHILDREN(softc->sysctl_tree), + OID_AUTO, "maxio", CTLTYPE_INT | CTLFLAG_RD, + &softc->maxio, 0, "Maximum I/O size"); + SYSCTL_ADD_INT(&softc->sysctl_ctx, SYSCTL_CHILDREN(softc->sysctl_tree), + OID_AUTO, "cpi_maxio", CTLTYPE_INT | CTLFLAG_RD, + &softc->cpi_maxio, 0, "Maximum Controller I/O size"); + +bailout: + /* + * Release the reference that was held when this task was enqueued. + */ + cam_periph_release(periph); +} + static cam_status saregister(struct cam_periph *periph, void *arg) { @@ -1455,6 +1522,7 @@ saregister(struct cam_periph *periph, void *arg) struct ccb_getdev *cgd; struct ccb_pathinq cpi; caddr_t match; + char tmpstr[80]; int i; cgd = (struct ccb_getdev *)arg; @@ -1509,21 +1577,55 @@ saregister(struct cam_periph *periph, void *arg) XPORT_DEVSTAT_TYPE(cpi.transport), DEVSTAT_PRIORITY_TAPE); /* - * If maxio isn't set, we fall back to DFLTPHYS. If it is set, we - * take it whether or not it's larger than MAXPHYS. physio will - * break it down into pieces small enough to fit in a buffer. + * Load the default value that is either compiled in, or loaded + * in the global kern.cam.sa.allow_io_split tunable. + */ + softc->allow_io_split = sa_allow_io_split; + + /* + * Load a per-instance tunable, if it exists. NOTE that this + * tunable WILL GO AWAY in FreeBSD 11.0. + */ + snprintf(tmpstr, sizeof(tmpstr), "kern.cam.sa.%u.allow_io_split", + periph->unit_number); + TUNABLE_INT_FETCH(tmpstr, &softc->allow_io_split); + + /* + * If maxio isn't set, we fall back to DFLTPHYS. Otherwise we take + * the smaller of cpi.maxio or MAXPHYS. */ if (cpi.maxio == 0) softc->maxio = DFLTPHYS; + else if (cpi.maxio > MAXPHYS) + softc->maxio = MAXPHYS; else softc->maxio = cpi.maxio; /* + * Record the controller's maximum I/O size so we can report it to + * the user later. + */ + softc->cpi_maxio = cpi.maxio; + + /* + * By default we tell physio that we do not want our I/O split. + * The user needs to have a 1:1 mapping between the size of his + * write to a tape character device and the size of the write + * that actually goes down to the drive. + */ + if (softc->allow_io_split == 0) + softc->si_flags = SI_NOSPLIT; + else + softc->si_flags = 0; + + TASK_INIT(&softc->sysctl_task, 0, sasysctlinit, periph); + + /* * If the SIM supports unmapped I/O, let physio know that we can * handle unmapped buffers. */ if (cpi.hba_misc & PIM_UNMAPPED) - softc->si_flags = SI_UNMAPPED; + softc->si_flags |= SI_UNMAPPED; softc->devs.ctl_dev = make_dev(&sa_cdevsw, SAMINOR(SA_CTLDEV, 0, SA_ATYPE_R), UID_ROOT, GID_OPERATOR, @@ -1586,6 +1688,13 @@ saregister(struct cam_periph *periph, void *arg) cam_periph_lock(periph); /* + * Bump the peripheral refcount for the sysctl thread, in case we + * get invalidated before the thread has a chance to run. + */ + cam_periph_acquire(periph); + taskqueue_enqueue(taskqueue_thread, &softc->sysctl_task); + + /* * Add an async callback so that we get * notified if this device goes away. */ |
