ioat: Handle channel-fatal HW errors safely

Certain invalid operations trigger hardware error conditions.  Error
conditions that only halt one channel can be detected and recovered by
resetting the channel.  Error conditions that halt the whole device are
generally not recoverable.

Add a sysctl to inject channel-fatal HW errors,
'dev.ioat.<N>.force_hw_error=1'.

When a halt due to a channel error is detected, ioat(4) blocks new
operations from being queued on the channel, completes any outstanding
operations with an error status, and resets the channel before allowing
new operations to be queued again.

Update ioat.4 to document error recovery;  document blockfill introduced
in r290021 while we are here;  document ioat_put_dmaengine() added in
r289907;  document DMA_NO_WAIT added in r289982.

Sponsored by:	EMC / Isilon Storage Division

6 files changed, 283 insertions, 56 deletions

diff --git a/share/man/man4/ioat.4 b/share/man/man4/ioat.4
index 301ab4f..62d85f1 100644
--- a/share/man/man4/ioat.4
+++ b/share/man/man4/ioat.4
@@ -24,14 +24,25 @@
 .\"
 .\" $FreeBSD$
 .\"
-.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
@@ -46,11 +57,13 @@ In
 (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"
@@ -65,6 +78,16 @@ In
 .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"
@@ -82,7 +105,9 @@ There is a number of DMA channels per CPU package.
 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.
@@ -92,6 +117,26 @@ All operations can optionally trigger an interrupt at completion with the
 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 .
@@ -101,10 +146,11 @@ the
 .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
@@ -114,6 +160,19 @@ The routine they provided for the
 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 .
@@ -135,19 +194,23 @@ The
 .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.
diff --git a/sys/dev/ioat/ioat.c b/sys/dev/ioat/ioat.c
index f946dc4..8245adf 100644
--- a/sys/dev/ioat/ioat.c
+++ b/sys/dev/ioat/ioat.c
@@ -38,6 +38,7 @@ __FBSDID("$FreeBSD$");
 #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>
@@ -65,6 +66,7 @@ static void ioat_dmamap_cb(void *arg, bus_dma_segment_t *segs, int nseg,
     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);
@@ -83,6 +85,7 @@ static int ring_grow(struct ioat_softc *, uint32_t oldorder,
     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);
@@ -94,8 +97,12 @@ static int sysctl_handle_reset(SYSCTL_HANDLER_ARGS);
 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 {					\
@@ -388,9 +395,15 @@ ioat3_attach(device_t device)
 	/* 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;
@@ -566,13 +579,30 @@ ioat_interrupt_handler(void *arg)
 	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);
 
@@ -590,8 +620,8 @@ ioat_process_events(struct ioat_softc *ioat)
 		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++;
@@ -613,6 +643,44 @@ out:
 
 	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));
 }
 
 /*
@@ -841,6 +909,7 @@ ioat_alloc_ring_entry(struct ioat_softc *ioat, int mflags)
 	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,
@@ -1168,13 +1237,13 @@ ioat_halted_debug(struct ioat_softc *ioat, uint32_t chanerr)
 	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
@@ -1182,53 +1251,43 @@ ioat_timer_callback(void *arg)
 {
 	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);
 }
 
 /*
@@ -1326,8 +1385,10 @@ ioat_reset_hw(struct ioat_softc *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;
 	}
@@ -1359,6 +1420,79 @@ out:
 }
 
 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)
 {
 	struct ioat_softc *ioat;
@@ -1435,6 +1569,12 @@ ioat_setup_sysctl(device_t device)
 	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 *
@@ -1458,6 +1598,21 @@ ioat_get(struct ioat_softc *ioat, enum ioat_ref_kind kind)
 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;
 
 	KASSERT(kind < IOAT_NUM_REF_KINDS, ("bogus"));
@@ -1479,13 +1634,18 @@ ioat_putn(struct ioat_softc *ioat, uint32_t n, enum ioat_ref_kind kind)
 			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
diff --git a/sys/dev/ioat/ioat.h b/sys/dev/ioat/ioat.h
index d72dcc5..c5a4855 100644
--- a/sys/dev/ioat/ioat.h
+++ b/sys/dev/ioat/ioat.h
@@ -50,7 +50,7 @@ __FBSDID("$FreeBSD$");
 
 typedef void *bus_dmaengine_t;
 struct bus_dmadesc;
-typedef void (*bus_dmaengine_callback_t)(void *arg);
+typedef void (*bus_dmaengine_callback_t)(void *arg, int error);
 
 /*
  * Called first to acquire a reference to the DMA channel
diff --git a/sys/dev/ioat/ioat_hw.h b/sys/dev/ioat/ioat_hw.h
index 99b8d3e..43c78ca 100644
--- a/sys/dev/ioat/ioat_hw.h
+++ b/sys/dev/ioat/ioat_hw.h
@@ -81,7 +81,9 @@ __FBSDID("$FreeBSD$");
 #define	IOAT_CHANCTRL_ERR_COMPLETION_EN		0x0004
 #define	IOAT_CHANCTRL_INT_REARM			0x0001
 #define	IOAT_CHANCTRL_RUN			(IOAT_CHANCTRL_INT_REARM |\
-						 IOAT_CHANCTRL_ANY_ERR_ABORT_EN)
+						 IOAT_CHANCTRL_ERR_COMPLETION_EN |\
+						 IOAT_CHANCTRL_ANY_ERR_ABORT_EN |\
+						 IOAT_CHANCTRL_ERR_INT_EN)
 
 #define	IOAT_CHANCMD_OFFSET		0x84
 #define	IOAT_CHANCMD_RESET		0x20
@@ -98,6 +100,7 @@ __FBSDID("$FreeBSD$");
 #define	IOAT_CHANSTS_IDLE		0x1
 #define	IOAT_CHANSTS_SUSPENDED		0x2
 #define	IOAT_CHANSTS_HALTED		0x3
+#define	IOAT_CHANSTS_ARMED		0x4
 
 #define	IOAT_CHANSTS_UNAFFILIATED_ERROR	0x8ULL
 #define	IOAT_CHANSTS_SOFT_ERROR		0x10ULL
diff --git a/sys/dev/ioat/ioat_internal.h b/sys/dev/ioat/ioat_internal.h
index 8bcf770..4ec738e 100644
--- a/sys/dev/ioat/ioat_internal.h
+++ b/sys/dev/ioat/ioat_internal.h
@@ -343,8 +343,6 @@ struct ioat_descriptor {
 		struct ioat_raw_hw_descriptor		*raw;
 	} u;
 	uint32_t		id;
-	uint32_t		length;
-	enum validate_flags	*validate_result;
 	bus_addr_t		hw_desc_bus_addr;
 };
 
diff --git a/sys/dev/ioat/ioat_test.c b/sys/dev/ioat/ioat_test.c
index 3b45e48..a8311ab 100644
--- a/sys/dev/ioat/ioat_test.c
+++ b/sys/dev/ioat/ioat_test.c
@@ -166,11 +166,14 @@ ioat_compare_ok(struct test_transaction *tx)
 }
 
 static void
-ioat_dma_test_callback(void *arg)
+ioat_dma_test_callback(void *arg, int error)
 {
 	struct test_transaction *tx;
 	struct ioat_test *test;
 
+	if (error != 0)
+		ioat_test_log(0, "%s: Got error: %d\n", __func__, error);
+
 	tx = arg;
 	test = tx->test;