.\"
.\" $FreeBSD$
.\"
-.Dd August 24, 2015
+.Dd October 31, 2015
.Dt IOAT 4
.Os
.Sh NAME
.Nm I/OAT
.Nd Intel I/O Acceleration Technology
.Sh SYNOPSIS
+To compile this driver into your kernel,
+place the following line in your kernel configuration file:
+.Bd -ragged -offset indent
.Cd "device ioat"
+.Ed
+.Pp
+Or, to load the driver as a module at boot, place the following line in
+.Xr loader.conf 5 :
+.Bd -literal -offset indent
+ioat_load="YES"
+.Ed
+.Pp
In
.Xr loader.conf 5 :
.Pp
(only critical errors; maximum of 3)
.Pp
.Ft typedef void
-.Fn (*bus_dmaengine_callback_t) "void *arg"
+.Fn (*bus_dmaengine_callback_t) "void *arg" "int error"
.Pp
.Ft bus_dmaengine_t
.Fn ioat_get_dmaengine "uint32_t channel_index"
.Ft void
+.Fn ioat_put_dmaengine "bus_dmaengine_t dmaengine"
+.Ft void
.Fn ioat_acquire "bus_dmaengine_t dmaengine"
.Ft void
.Fn ioat_release "bus_dmaengine_t dmaengine"
.Fa "uint32_t flags"
.Fc
.Ft struct bus_dmadesc *
+.Fo ioat_blockfill
+.Fa "bus_dmaengine_t dmaengine"
+.Fa "bus_addr_t dst"
+.Fa "uint64_t fillpattern"
+.Fa "bus_size_t len"
+.Fa "bus_dmaengine_callback_t callback_fn"
+.Fa "void *callback_arg"
+.Fa "uint32_t flags"
+.Fc
+.Ft struct bus_dmadesc *
.Fo ioat_null
.Fa "bus_dmaengine_t dmaengine"
.Fa "bus_dmaengine_callback_t callback_fn"
Each may be used independently.
Operations on a single channel proceed sequentially.
.Pp
-Copy operations may be used to offload memory copies to the DMA engines.
+Blockfill operations can be used to write a 64-bit pattern to memory.
+.Pp
+Copy operations can be used to offload memory copies to the DMA engines.
.Pp
Null operations do nothing, but may be used to test the interrupt and callback
mechanism.
flag.
For example, a user might submit multiple operations to the same channel and
only enable an interrupt and callback for the last operation.
+.Pp
+All operations are safe to use in a non-blocking context with the
+.Ar DMA_NO_WAIT
+flag.
+(Of course, allocations may fail and operations requested with
+.Ar DMA_NO_WAIT
+may return NULL.)
+.Pp
+All operations, as well as
+.Fn ioat_get_dmaengine ,
+can return NULL in special circumstances.
+For example, if the
+.Nm
+driver is being unloaded, or the administrator has induced a hardware reset, or
+a usage error has resulted in a hardware error state that needs to be recovered
+from.
+.Pp
+It is invalid to attempt to submit new DMA operations in a
+.Fa bus_dmaengine_callback_t
+context.
.Sh USAGE
A typical user will lookup the DMA engine object for a given channel with
.Fn ioat_get_dmaengine .
.Ar bus_dmaengine_t
object for exclusive access to enqueue operations on that channel.
Then, they will submit one or more operations using
-.Fn ioat_copy
+.Fn ioat_blockfill ,
+.Fn ioat_copy ,
or
.Fn ioat_null .
-Finally, they will
+After queueing one or more individual DMA operations, they will
.Fn ioat_release
the
.Ar bus_dmaengine_t
argument will be invoked with the provided
.Fa callback_arg
when the operation is complete.
+When they are finished with the
+.Ar bus_dmaengine_t ,
+the user should
+.Fn ioat_put_dmaengine .
+.Pp
+Users MUST NOT block between
+.Fn ioat_acquire
+and
+.Fn ioat_release .
+Users SHOULD NOT hold
+.Ar bus_dmaengine_t
+references for a very long time to enable fault recovery and kernel module
+unload.
.Pp
For an example of usage, see
.Pa src/sys/dev/ioat/ioat_test.c .
.Nm
driver was developed by
.An \&Jim Harris Aq Mt jimharris@FreeBSD.org ,
+.An \&Carl Delsey Aq Mt carl.r.delsey@intel.com ,
and
-.An \&Carl Delsey Aq Mt carl.r.delsey@intel.com .
+.An \&Conrad Meyer Aq Mt cem@FreeBSD.org .
This manual page was written by
.An \&Conrad Meyer Aq Mt cem@FreeBSD.org .
.Sh CAVEATS
Copy operation takes bus addresses as parameters, not virtual addresses.
.Pp
-Copies larger than max transfer size (1MB) are not supported.
+Buffers for individual copy operations must be physically contiguous.
+.Pp
+Copies larger than max transfer size (1MB, but may vary by hardware) are not
+supported.
Future versions will likely support this by breaking up the transfer into
smaller sizes.
.Sh BUGS
The
.Nm
-driver only supports copy and null operations at this time.
+driver only supports blockfill, copy, and null operations at this time.
The driver does not yet support advanced DMA modes, such as XOR, that some
I/OAT devices support.
#include <sys/module.h>
#include <sys/mutex.h>
#include <sys/rman.h>
+#include <sys/sbuf.h>
#include <sys/sysctl.h>
#include <sys/time.h>
#include <dev/pci/pcireg.h>
int error);
static void ioat_interrupt_handler(void *arg);
static boolean_t ioat_model_resets_msix(struct ioat_softc *ioat);
+static int chanerr_to_errno(uint32_t);
static void ioat_process_events(struct ioat_softc *ioat);
static inline uint32_t ioat_get_active(struct ioat_softc *ioat);
static inline uint32_t ioat_get_ring_space(struct ioat_softc *ioat);
struct ioat_descriptor **);
static int ring_shrink(struct ioat_softc *, uint32_t oldorder,
struct ioat_descriptor **);
+static void ioat_halted_debug(struct ioat_softc *, uint32_t);
static void ioat_timer_callback(void *arg);
static void dump_descriptor(void *hw_desc);
static void ioat_submit_single(struct ioat_softc *ioat);
static inline struct ioat_softc *ioat_get(struct ioat_softc *,
enum ioat_ref_kind);
static inline void ioat_put(struct ioat_softc *, enum ioat_ref_kind);
+static inline void _ioat_putn(struct ioat_softc *, uint32_t,
+ enum ioat_ref_kind, boolean_t);
static inline void ioat_putn(struct ioat_softc *, uint32_t,
enum ioat_ref_kind);
+static inline void ioat_putn_locked(struct ioat_softc *, uint32_t,
+ enum ioat_ref_kind);
static void ioat_drain_locked(struct ioat_softc *);
#define ioat_log_message(v, ...) do { \
/* TODO: need to check DCA here if we ever do XOR/PQ */
mtx_init(&ioat->submit_lock, "ioat_submit", NULL, MTX_DEF);
- mtx_init(&ioat->cleanup_lock, "ioat_process_events", NULL, MTX_DEF);
+ mtx_init(&ioat->cleanup_lock, "ioat_cleanup", NULL, MTX_DEF);
callout_init(&ioat->timer, 1);
+ /* Establish lock order for Witness */
+ mtx_lock(&ioat->submit_lock);
+ mtx_lock(&ioat->cleanup_lock);
+ mtx_unlock(&ioat->cleanup_lock);
+ mtx_unlock(&ioat->submit_lock);
+
ioat->is_resize_pending = FALSE;
ioat->is_completion_pending = FALSE;
ioat->is_reset_pending = FALSE;
ioat_process_events(ioat);
}
+static int
+chanerr_to_errno(uint32_t chanerr)
+{
+
+ if (chanerr == 0)
+ return (0);
+ if ((chanerr & (IOAT_CHANERR_XSADDERR | IOAT_CHANERR_XDADDERR)) != 0)
+ return (EFAULT);
+ if ((chanerr & (IOAT_CHANERR_RDERR | IOAT_CHANERR_WDERR)) != 0)
+ return (EIO);
+ /* This one is probably our fault: */
+ if ((chanerr & IOAT_CHANERR_NDADDERR) != 0)
+ return (EIO);
+ return (EIO);
+}
+
static void
ioat_process_events(struct ioat_softc *ioat)
{
struct ioat_descriptor *desc;
struct bus_dmadesc *dmadesc;
uint64_t comp_update, status;
- uint32_t completed;
+ uint32_t completed, chanerr;
+ int error;
mtx_lock(&ioat->cleanup_lock);
dmadesc = &desc->bus_dmadesc;
CTR1(KTR_IOAT, "completing desc %d", ioat->tail);
- if (dmadesc->callback_fn)
- (*dmadesc->callback_fn)(dmadesc->callback_arg);
+ if (dmadesc->callback_fn != NULL)
+ dmadesc->callback_fn(dmadesc->callback_arg, 0);
completed++;
ioat->tail++;
ioat_putn(ioat, completed, IOAT_ACTIVE_DESCR_REF);
wakeup(&ioat->tail);
+
+ if (!is_ioat_halted(comp_update))
+ return;
+
+ /*
+ * Fatal programming error on this DMA channel. Flush any outstanding
+ * work with error status and restart the engine.
+ */
+ ioat_log_message(0, "Channel halted due to fatal programming error\n");
+ mtx_lock(&ioat->submit_lock);
+ mtx_lock(&ioat->cleanup_lock);
+ ioat->quiescing = TRUE;
+
+ chanerr = ioat_read_4(ioat, IOAT_CHANERR_OFFSET);
+ ioat_halted_debug(ioat, chanerr);
+
+ while (ioat_get_active(ioat) > 0) {
+ desc = ioat_get_ring_entry(ioat, ioat->tail);
+ dmadesc = &desc->bus_dmadesc;
+ CTR1(KTR_IOAT, "completing err desc %d", ioat->tail);
+
+ if (dmadesc->callback_fn != NULL)
+ dmadesc->callback_fn(dmadesc->callback_arg,
+ chanerr_to_errno(chanerr));
+
+ ioat_putn_locked(ioat, 1, IOAT_ACTIVE_DESCR_REF);
+ ioat->tail++;
+ }
+
+ /* Clear error status */
+ ioat_write_4(ioat, IOAT_CHANERR_OFFSET, chanerr);
+
+ mtx_unlock(&ioat->cleanup_lock);
+ mtx_unlock(&ioat->submit_lock);
+
+ ioat_log_message(0, "Resetting channel to recover from error\n");
+ error = ioat_reset_hw(ioat);
+ KASSERT(error == 0, ("%s: reset failed: %d", __func__, error));
}
/*
if (hw_desc == NULL)
goto out;
+ memset(&desc->bus_dmadesc, 0, sizeof(desc->bus_dmadesc));
desc->u.generic = hw_desc;
error = bus_dmamap_load(ioat->hw_desc_tag, ioat->hw_desc_map, hw_desc,
if (chanerr == 0)
return;
- mtx_lock(&ioat->submit_lock);
+ mtx_assert(&ioat->cleanup_lock, MA_OWNED);
+
desc = ioat_get_ring_entry(ioat, ioat->tail + 0);
dump_descriptor(desc->u.raw);
desc = ioat_get_ring_entry(ioat, ioat->tail + 1);
dump_descriptor(desc->u.raw);
- mtx_unlock(&ioat->submit_lock);
}
static void
{
struct ioat_descriptor **newring;
struct ioat_softc *ioat;
- uint64_t status;
- uint32_t chanerr, order;
+ uint32_t order;
ioat = arg;
ioat_log_message(1, "%s\n", __func__);
if (ioat->is_completion_pending) {
- status = ioat_get_chansts(ioat);
-
- /*
- * When halted due to errors, check for channel programming
- * errors before advancing the completion state.
- */
- if (is_ioat_halted(status)) {
- chanerr = ioat_read_4(ioat, IOAT_CHANERR_OFFSET);
- ioat_halted_debug(ioat, chanerr);
- }
ioat_process_events(ioat);
- } else {
- mtx_lock(&ioat->submit_lock);
- order = ioat->ring_size_order;
- if (ioat->is_resize_pending || order == IOAT_MIN_ORDER) {
- mtx_unlock(&ioat->submit_lock);
- goto out;
- }
- ioat->is_resize_pending = TRUE;
+ return;
+ }
+
+ /* Slowly scale the ring down if idle. */
+ mtx_lock(&ioat->submit_lock);
+ order = ioat->ring_size_order;
+ if (ioat->is_resize_pending || order == IOAT_MIN_ORDER) {
mtx_unlock(&ioat->submit_lock);
+ goto out;
+ }
+ ioat->is_resize_pending = TRUE;
+ mtx_unlock(&ioat->submit_lock);
- newring = ioat_prealloc_ring(ioat, 1 << (order - 1), FALSE,
- M_NOWAIT);
+ newring = ioat_prealloc_ring(ioat, 1 << (order - 1), FALSE,
+ M_NOWAIT);
- mtx_lock(&ioat->submit_lock);
- KASSERT(ioat->ring_size_order == order,
- ("resize_pending protects order"));
+ mtx_lock(&ioat->submit_lock);
+ KASSERT(ioat->ring_size_order == order,
+ ("resize_pending protects order"));
- if (newring != NULL)
- ring_shrink(ioat, order, newring);
+ if (newring != NULL)
+ ring_shrink(ioat, order, newring);
- ioat->is_resize_pending = FALSE;
- mtx_unlock(&ioat->submit_lock);
+ ioat->is_resize_pending = FALSE;
+ mtx_unlock(&ioat->submit_lock);
out:
- /* Slowly scale the ring down if idle. */
- if (ioat->ring_size_order > IOAT_MIN_ORDER)
- callout_reset(&ioat->timer, 10 * hz,
- ioat_timer_callback, ioat);
- }
+ if (ioat->ring_size_order > IOAT_MIN_ORDER)
+ callout_reset(&ioat->timer, 10 * hz,
+ ioat_timer_callback, ioat);
}
/*
}
chanerr = ioat_read_4(ioat, IOAT_CHANERR_OFFSET);
- ioat_halted_debug(ioat, chanerr);
if (chanerr != 0) {
+ mtx_lock(&ioat->cleanup_lock);
+ ioat_halted_debug(ioat, chanerr);
+ mtx_unlock(&ioat->cleanup_lock);
error = EIO;
goto out;
}
return (error);
}
+static int
+sysctl_handle_chansts(SYSCTL_HANDLER_ARGS)
+{
+ struct ioat_softc *ioat;
+ struct sbuf sb;
+ uint64_t status;
+ int error;
+
+ ioat = arg1;
+
+ status = ioat_get_chansts(ioat) & IOAT_CHANSTS_STATUS;
+
+ sbuf_new_for_sysctl(&sb, NULL, 256, req);
+ switch (status) {
+ case IOAT_CHANSTS_ACTIVE:
+ sbuf_printf(&sb, "ACTIVE");
+ break;
+ case IOAT_CHANSTS_IDLE:
+ sbuf_printf(&sb, "IDLE");
+ break;
+ case IOAT_CHANSTS_SUSPENDED:
+ sbuf_printf(&sb, "SUSPENDED");
+ break;
+ case IOAT_CHANSTS_HALTED:
+ sbuf_printf(&sb, "HALTED");
+ break;
+ case IOAT_CHANSTS_ARMED:
+ sbuf_printf(&sb, "ARMED");
+ break;
+ default:
+ sbuf_printf(&sb, "UNKNOWN");
+ break;
+ }
+ error = sbuf_finish(&sb);
+ sbuf_delete(&sb);
+
+ if (error != 0 || req->newptr == NULL)
+ return (error);
+ return (EINVAL);
+}
+
+static int
+sysctl_handle_error(SYSCTL_HANDLER_ARGS)
+{
+ struct ioat_descriptor *desc;
+ struct ioat_softc *ioat;
+ int error, arg;
+
+ ioat = arg1;
+
+ arg = 0;
+ error = SYSCTL_OUT(req, &arg, sizeof(arg));
+ if (error != 0 || req->newptr == NULL)
+ return (error);
+
+ error = SYSCTL_IN(req, &arg, sizeof(arg));
+ if (error != 0)
+ return (error);
+
+ if (arg != 0) {
+ ioat_acquire(&ioat->dmaengine);
+ desc = ioat_op_generic(ioat, IOAT_OP_COPY, 1,
+ 0xffff000000000000ull, 0xffff000000000000ull, NULL, NULL,
+ 0);
+ if (desc == NULL)
+ error = ENOMEM;
+ else
+ ioat_submit_single(ioat);
+ ioat_release(&ioat->dmaengine);
+ }
+ return (error);
+}
+
static int
sysctl_handle_reset(SYSCTL_HANDLER_ARGS)
{
SYSCTL_ADD_PROC(ctx, par, OID_AUTO, "force_hw_reset",
CTLTYPE_INT | CTLFLAG_RW, ioat, 0, sysctl_handle_reset, "I",
"Set to non-zero to reset the hardware");
+ SYSCTL_ADD_PROC(ctx, par, OID_AUTO, "force_hw_error",
+ CTLTYPE_INT | CTLFLAG_RW, ioat, 0, sysctl_handle_error, "I",
+ "Set to non-zero to inject a recoverable hardware error");
+ SYSCTL_ADD_PROC(ctx, par, OID_AUTO, "chansts",
+ CTLTYPE_STRING | CTLFLAG_RD, ioat, 0, sysctl_handle_chansts, "A",
+ "String of the channel status");
}
static inline struct ioat_softc *
static inline void
ioat_putn(struct ioat_softc *ioat, uint32_t n, enum ioat_ref_kind kind)
+{
+
+ _ioat_putn(ioat, n, kind, FALSE);
+}
+
+static inline void
+ioat_putn_locked(struct ioat_softc *ioat, uint32_t n, enum ioat_ref_kind kind)
+{
+
+ _ioat_putn(ioat, n, kind, TRUE);
+}
+
+static inline void
+_ioat_putn(struct ioat_softc *ioat, uint32_t n, enum ioat_ref_kind kind,
+ boolean_t locked)
{
uint32_t old;
return;
}
- mtx_lock(IOAT_REFLK);
+ if (locked)
+ mtx_assert(IOAT_REFLK, MA_OWNED);
+ else
+ mtx_lock(IOAT_REFLK);
+
old = atomic_fetchadd_32(&ioat->refcnt, -n);
KASSERT(old >= n, ("refcnt error"));
if (old == n)
wakeup(IOAT_REFLK);
- mtx_unlock(IOAT_REFLK);
+ if (!locked)
+ mtx_unlock(IOAT_REFLK);
}
static inline void
projects / people / julieng / freebsd.git / commitdiff