ioat(4): Simplify by removing dynamic scaling
This paves the way for a contiguous descriptor array. A contiguous descriptor array has the benefit that we can make strong assertions about whether an address is a valid descriptor or not. The other benefit is that future generations of I/OAT hardware will require a contiguous descriptor array anyway. The downside is that after system boot, big chunks of contiguous memory is much harder to find. So dynamic scaling after boot is basically impossible. Reviewed by: markj Sponsored by: Dell EMC Isilon
This commit is contained in:
cem
parent
d9353248ee
commit
77a763e63a
@ -63,7 +63,6 @@ __FBSDID("$FreeBSD$");
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#define BUS_SPACE_MAXADDR_40BIT 0xFFFFFFFFFFULL
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#endif
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#define IOAT_REFLK (&ioat->submit_lock)
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#define IOAT_SHRINK_PERIOD (10 * hz)
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static int ioat_probe(device_t device);
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static int ioat_attach(device_t device);
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@ -90,15 +89,8 @@ static struct ioat_descriptor *ioat_alloc_ring_entry(struct ioat_softc *,
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static int ioat_reserve_space(struct ioat_softc *, uint32_t, int mflags);
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static struct ioat_descriptor *ioat_get_ring_entry(struct ioat_softc *ioat,
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uint32_t index);
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static struct ioat_descriptor **ioat_prealloc_ring(struct ioat_softc *,
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uint32_t size, boolean_t need_dscr, int mflags);
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static int ring_grow(struct ioat_softc *, uint32_t oldorder,
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struct ioat_descriptor **);
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static int ring_shrink(struct ioat_softc *, uint32_t oldorder,
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struct ioat_descriptor **);
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static void ioat_halted_debug(struct ioat_softc *, uint32_t);
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static void ioat_poll_timer_callback(void *arg);
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static void ioat_shrink_timer_callback(void *arg);
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static void dump_descriptor(void *hw_desc);
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static void ioat_submit_single(struct ioat_softc *ioat);
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static void ioat_comp_update_map(void *arg, bus_dma_segment_t *seg, int nseg,
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@ -135,6 +127,10 @@ int g_ioat_debug_level = 0;
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SYSCTL_INT(_hw_ioat, OID_AUTO, debug_level, CTLFLAG_RWTUN, &g_ioat_debug_level,
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0, "Set log level (0-3) for ioat(4). Higher is more verbose.");
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unsigned g_ioat_ring_order = 13;
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SYSCTL_UINT(_hw_ioat, OID_AUTO, ring_order, CTLFLAG_RDTUN, &g_ioat_ring_order,
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0, "Set IOAT ring order. (1 << this) == ring size.");
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/*
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* OS <-> Driver interface structures
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*/
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@ -336,7 +332,6 @@ ioat_detach(device_t device)
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ioat_teardown_intr(ioat);
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callout_drain(&ioat->poll_timer);
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callout_drain(&ioat->shrink_timer);
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pci_disable_busmaster(device);
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@ -453,7 +448,6 @@ ioat3_attach(device_t device)
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mtx_init(&ioat->submit_lock, "ioat_submit", NULL, MTX_DEF);
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mtx_init(&ioat->cleanup_lock, "ioat_cleanup", NULL, MTX_DEF);
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callout_init(&ioat->poll_timer, 1);
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callout_init(&ioat->shrink_timer, 1);
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TASK_INIT(&ioat->reset_task, 0, ioat_reset_hw_task, ioat);
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/* Establish lock order for Witness */
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@ -462,7 +456,6 @@ ioat3_attach(device_t device)
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mtx_unlock(&ioat->cleanup_lock);
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mtx_unlock(&ioat->submit_lock);
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ioat->is_resize_pending = FALSE;
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ioat->is_submitter_processing = FALSE;
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ioat->is_completion_pending = FALSE;
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ioat->is_reset_pending = FALSE;
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@ -484,7 +477,7 @@ ioat3_attach(device_t device)
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if (error != 0)
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return (error);
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ioat->ring_size_order = IOAT_MIN_ORDER;
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ioat->ring_size_order = g_ioat_ring_order;
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num_descriptors = 1 << ioat->ring_size_order;
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@ -725,8 +718,6 @@ ioat_process_events(struct ioat_softc *ioat)
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pending = (ioat_get_active(ioat) != 0);
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if (!pending && ioat->is_completion_pending) {
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ioat->is_completion_pending = FALSE;
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callout_reset(&ioat->shrink_timer, IOAT_SHRINK_PERIOD,
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ioat_shrink_timer_callback, ioat);
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callout_stop(&ioat->poll_timer);
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}
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mtx_unlock(&ioat->submit_lock);
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@ -781,8 +772,6 @@ ioat_process_events(struct ioat_softc *ioat)
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if (ioat->is_completion_pending) {
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ioat->is_completion_pending = FALSE;
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callout_reset(&ioat->shrink_timer, IOAT_SHRINK_PERIOD,
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ioat_shrink_timer_callback, ioat);
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callout_stop(&ioat->poll_timer);
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}
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@ -964,7 +953,6 @@ ioat_release(bus_dmaengine_t dmaengine)
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ioat->is_completion_pending = TRUE;
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callout_reset(&ioat->poll_timer, 1, ioat_poll_timer_callback,
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ioat);
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callout_stop(&ioat->shrink_timer);
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}
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mtx_unlock(&ioat->submit_lock);
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}
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@ -1402,8 +1390,6 @@ ioat_free_ring_entry(struct ioat_softc *ioat, struct ioat_descriptor *desc)
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static int
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ioat_reserve_space(struct ioat_softc *ioat, uint32_t num_descs, int mflags)
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{
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struct ioat_descriptor **new_ring;
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uint32_t order;
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boolean_t dug;
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int error;
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@ -1411,7 +1397,7 @@ ioat_reserve_space(struct ioat_softc *ioat, uint32_t num_descs, int mflags)
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error = 0;
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dug = FALSE;
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if (num_descs < 1 || num_descs >= (1 << IOAT_MAX_ORDER)) {
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if (num_descs < 1 || num_descs >= (1 << ioat->ring_size_order)) {
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error = EINVAL;
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goto out;
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}
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@ -1428,8 +1414,7 @@ ioat_reserve_space(struct ioat_softc *ioat, uint32_t num_descs, int mflags)
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CTR3(KTR_IOAT, "%s channel=%u starved (%u)", __func__,
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ioat->chan_idx, num_descs);
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if (!dug && !ioat->is_submitter_processing &&
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(1 << ioat->ring_size_order) > num_descs) {
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if (!dug && !ioat->is_submitter_processing) {
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ioat->is_submitter_processing = TRUE;
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mtx_unlock(&ioat->submit_lock);
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@ -1446,46 +1431,15 @@ ioat_reserve_space(struct ioat_softc *ioat, uint32_t num_descs, int mflags)
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continue;
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}
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order = ioat->ring_size_order;
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if (ioat->is_resize_pending || order == IOAT_MAX_ORDER) {
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if ((mflags & M_WAITOK) != 0) {
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CTR2(KTR_IOAT, "%s channel=%u blocking on completions",
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__func__, ioat->chan_idx);
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msleep(&ioat->tail, &ioat->submit_lock, 0,
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"ioat_rsz", 0);
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continue;
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}
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if ((mflags & M_WAITOK) == 0) {
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error = EAGAIN;
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break;
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}
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ioat->is_resize_pending = TRUE;
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for (;;) {
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mtx_unlock(&ioat->submit_lock);
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new_ring = ioat_prealloc_ring(ioat, 1 << (order + 1),
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TRUE, mflags);
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mtx_lock(&ioat->submit_lock);
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KASSERT(ioat->ring_size_order == order,
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("is_resize_pending should protect order"));
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if (new_ring == NULL) {
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KASSERT((mflags & M_WAITOK) == 0,
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("allocation failed"));
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error = EAGAIN;
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break;
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}
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error = ring_grow(ioat, order, new_ring);
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if (error == 0)
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break;
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}
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ioat->is_resize_pending = FALSE;
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wakeup(&ioat->tail);
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if (error)
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break;
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CTR2(KTR_IOAT, "%s channel=%u blocking on completions",
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__func__, ioat->chan_idx);
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msleep(&ioat->tail, &ioat->submit_lock, 0,
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"ioat_full", 0);
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continue;
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}
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out:
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@ -1495,39 +1449,6 @@ ioat_reserve_space(struct ioat_softc *ioat, uint32_t num_descs, int mflags)
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return (error);
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}
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static struct ioat_descriptor **
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ioat_prealloc_ring(struct ioat_softc *ioat, uint32_t size, boolean_t need_dscr,
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int mflags)
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{
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struct ioat_descriptor **ring;
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uint32_t i;
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int error;
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KASSERT(size > 0 && powerof2(size), ("bogus size"));
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ring = malloc(size * sizeof(*ring), M_IOAT, M_ZERO | mflags);
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if (ring == NULL)
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return (NULL);
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if (need_dscr) {
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error = ENOMEM;
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for (i = size / 2; i < size; i++) {
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ring[i] = ioat_alloc_ring_entry(ioat, mflags);
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if (ring[i] == NULL)
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goto out;
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ring[i]->id = i;
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}
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}
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error = 0;
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out:
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if (error != 0 && ring != NULL) {
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ioat_free_ring(ioat, size, ring);
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ring = NULL;
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}
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return (ring);
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}
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static void
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ioat_free_ring(struct ioat_softc *ioat, uint32_t size,
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struct ioat_descriptor **ring)
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@ -1548,181 +1469,6 @@ ioat_get_ring_entry(struct ioat_softc *ioat, uint32_t index)
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return (ioat->ring[index % (1 << ioat->ring_size_order)]);
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}
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static int
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ring_grow(struct ioat_softc *ioat, uint32_t oldorder,
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struct ioat_descriptor **newring)
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{
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struct ioat_descriptor *tmp, *next;
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struct ioat_dma_hw_descriptor *hw;
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uint32_t oldsize, newsize, head, tail, i, end;
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int error;
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CTR2(KTR_IOAT, "%s channel=%u", __func__, ioat->chan_idx);
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mtx_assert(&ioat->submit_lock, MA_OWNED);
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if (oldorder != ioat->ring_size_order || oldorder >= IOAT_MAX_ORDER) {
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error = EINVAL;
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goto out;
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}
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oldsize = (1 << oldorder);
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newsize = (1 << (oldorder + 1));
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mtx_lock(&ioat->cleanup_lock);
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head = ioat->head & (oldsize - 1);
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tail = ioat->tail & (oldsize - 1);
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/* Copy old descriptors to new ring */
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for (i = 0; i < oldsize; i++)
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newring[i] = ioat->ring[i];
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/*
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* If head has wrapped but tail hasn't, we must swap some descriptors
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* around so that tail can increment directly to head.
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*/
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if (head < tail) {
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for (i = 0; i <= head; i++) {
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tmp = newring[oldsize + i];
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newring[oldsize + i] = newring[i];
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newring[oldsize + i]->id = oldsize + i;
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newring[i] = tmp;
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newring[i]->id = i;
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}
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head += oldsize;
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}
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KASSERT(head >= tail, ("invariants"));
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/* Head didn't wrap; we only need to link in oldsize..newsize */
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if (head < oldsize) {
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i = oldsize - 1;
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end = newsize;
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} else {
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/* Head did wrap; link newhead..newsize and 0..oldhead */
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i = head;
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end = newsize + (head - oldsize) + 1;
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}
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/*
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* Fix up hardware ring, being careful not to trample the active
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* section (tail -> head).
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*/
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for (; i < end; i++) {
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KASSERT((i & (newsize - 1)) < tail ||
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(i & (newsize - 1)) >= head, ("trampling snake"));
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next = newring[(i + 1) & (newsize - 1)];
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hw = newring[i & (newsize - 1)]->u.dma;
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hw->next = next->hw_desc_bus_addr;
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}
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#ifdef INVARIANTS
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for (i = 0; i < newsize; i++) {
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next = newring[(i + 1) & (newsize - 1)];
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hw = newring[i & (newsize - 1)]->u.dma;
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KASSERT(hw->next == next->hw_desc_bus_addr,
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("mismatch at i:%u (oldsize:%u); next=%p nextaddr=0x%lx"
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" (tail:%u)", i, oldsize, next, next->hw_desc_bus_addr,
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tail));
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}
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#endif
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free(ioat->ring, M_IOAT);
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ioat->ring = newring;
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ioat->ring_size_order = oldorder + 1;
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ioat->tail = tail;
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ioat->head = head;
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error = 0;
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mtx_unlock(&ioat->cleanup_lock);
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out:
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if (error)
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ioat_free_ring(ioat, (1 << (oldorder + 1)), newring);
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return (error);
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}
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static int
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ring_shrink(struct ioat_softc *ioat, uint32_t oldorder,
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struct ioat_descriptor **newring)
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{
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struct ioat_dma_hw_descriptor *hw;
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struct ioat_descriptor *ent, *next;
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uint32_t oldsize, newsize, current_idx, new_idx, i;
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int error;
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CTR2(KTR_IOAT, "%s channel=%u", __func__, ioat->chan_idx);
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mtx_assert(&ioat->submit_lock, MA_OWNED);
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if (oldorder != ioat->ring_size_order || oldorder <= IOAT_MIN_ORDER) {
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error = EINVAL;
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goto out_unlocked;
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}
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oldsize = (1 << oldorder);
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newsize = (1 << (oldorder - 1));
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mtx_lock(&ioat->cleanup_lock);
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/* Can't shrink below current active set! */
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if (ioat_get_active(ioat) >= newsize) {
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error = ENOMEM;
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goto out;
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}
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/*
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* Copy current descriptors to the new ring, dropping the removed
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* descriptors.
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*/
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for (i = 0; i < newsize; i++) {
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current_idx = (ioat->tail + i) & (oldsize - 1);
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new_idx = (ioat->tail + i) & (newsize - 1);
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newring[new_idx] = ioat->ring[current_idx];
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newring[new_idx]->id = new_idx;
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}
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/* Free deleted descriptors */
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for (i = newsize; i < oldsize; i++) {
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ent = ioat_get_ring_entry(ioat, ioat->tail + i);
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ioat_free_ring_entry(ioat, ent);
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}
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/* Fix up hardware ring. */
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hw = newring[(ioat->tail + newsize - 1) & (newsize - 1)]->u.dma;
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next = newring[(ioat->tail + newsize) & (newsize - 1)];
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hw->next = next->hw_desc_bus_addr;
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#ifdef INVARIANTS
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for (i = 0; i < newsize; i++) {
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next = newring[(i + 1) & (newsize - 1)];
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hw = newring[i & (newsize - 1)]->u.dma;
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KASSERT(hw->next == next->hw_desc_bus_addr,
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("mismatch at i:%u (newsize:%u); next=%p nextaddr=0x%lx "
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"(tail:%u)", i, newsize, next, next->hw_desc_bus_addr,
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ioat->tail));
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}
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#endif
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free(ioat->ring, M_IOAT);
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ioat->ring = newring;
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ioat->ring_size_order = oldorder - 1;
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error = 0;
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out:
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mtx_unlock(&ioat->cleanup_lock);
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out_unlocked:
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if (error)
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ioat_free_ring(ioat, (1 << (oldorder - 1)), newring);
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return (error);
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}
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static void
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ioat_halted_debug(struct ioat_softc *ioat, uint32_t chanerr)
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{
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@ -1753,55 +1499,6 @@ ioat_poll_timer_callback(void *arg)
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ioat_process_events(ioat);
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}
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static void
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ioat_shrink_timer_callback(void *arg)
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{
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struct ioat_descriptor **newring;
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struct ioat_softc *ioat;
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uint32_t order;
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ioat = arg;
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ioat_log_message(1, "%s\n", __func__);
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/* Slowly scale the ring down if idle. */
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mtx_lock(&ioat->submit_lock);
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/* Don't run while the hardware is being reset. */
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if (ioat->resetting) {
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mtx_unlock(&ioat->submit_lock);
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return;
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}
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order = ioat->ring_size_order;
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if (ioat->is_completion_pending || ioat->is_resize_pending ||
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order == IOAT_MIN_ORDER) {
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mtx_unlock(&ioat->submit_lock);
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goto out;
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}
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ioat->is_resize_pending = TRUE;
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mtx_unlock(&ioat->submit_lock);
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newring = ioat_prealloc_ring(ioat, 1 << (order - 1), FALSE,
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M_NOWAIT);
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mtx_lock(&ioat->submit_lock);
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KASSERT(ioat->ring_size_order == order,
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("resize_pending protects order"));
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if (newring != NULL && !ioat->is_completion_pending)
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ring_shrink(ioat, order, newring);
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else if (newring != NULL)
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ioat_free_ring(ioat, (1 << (order - 1)), newring);
|
||||
|
||||
ioat->is_resize_pending = FALSE;
|
||||
mtx_unlock(&ioat->submit_lock);
|
||||
|
||||
out:
|
||||
if (ioat->ring_size_order > IOAT_MIN_ORDER)
|
||||
callout_reset(&ioat->shrink_timer, IOAT_SHRINK_PERIOD,
|
||||
ioat_shrink_timer_callback, ioat);
|
||||
}
|
||||
|
||||
/*
|
||||
* Support Functions
|
||||
*/
|
||||
@ -2128,8 +1825,6 @@ ioat_setup_sysctl(device_t device)
|
||||
SYSCTL_ADD_UQUAD(ctx, state, OID_AUTO, "last_completion", CTLFLAG_RD,
|
||||
ioat->comp_update, "HW addr of last completion");
|
||||
|
||||
SYSCTL_ADD_INT(ctx, state, OID_AUTO, "is_resize_pending", CTLFLAG_RD,
|
||||
&ioat->is_resize_pending, 0, "resize pending");
|
||||
SYSCTL_ADD_INT(ctx, state, OID_AUTO, "is_submitter_processing",
|
||||
CTLFLAG_RD, &ioat->is_submitter_processing, 0,
|
||||
"submitter processing");
|
||||
@ -2307,16 +2002,8 @@ DB_SHOW_COMMAND(ioat, db_show_ioat)
|
||||
db_printf(" c_lock: %p\n", sc->poll_timer.c_lock);
|
||||
db_printf(" c_flags: 0x%x\n", (unsigned)sc->poll_timer.c_flags);
|
||||
|
||||
db_printf(" shrink_timer:\n");
|
||||
db_printf(" c_time: %ju\n", (uintmax_t)sc->shrink_timer.c_time);
|
||||
db_printf(" c_arg: %p\n", sc->shrink_timer.c_arg);
|
||||
db_printf(" c_func: %p\n", sc->shrink_timer.c_func);
|
||||
db_printf(" c_lock: %p\n", sc->shrink_timer.c_lock);
|
||||
db_printf(" c_flags: 0x%x\n", (unsigned)sc->shrink_timer.c_flags);
|
||||
|
||||
db_printf(" quiescing: %d\n", (int)sc->quiescing);
|
||||
db_printf(" destroying: %d\n", (int)sc->destroying);
|
||||
db_printf(" is_resize_pending: %d\n", (int)sc->is_resize_pending);
|
||||
db_printf(" is_submitter_processing: %d\n",
|
||||
(int)sc->is_submitter_processing);
|
||||
db_printf(" is_completion_pending: %d\n", (int)sc->is_completion_pending);
|
||||
|
||||
@ -487,7 +487,6 @@ struct ioat_softc {
|
||||
boolean_t quiescing;
|
||||
boolean_t destroying;
|
||||
boolean_t is_submitter_processing;
|
||||
boolean_t is_resize_pending;
|
||||
boolean_t is_completion_pending; /* submit_lock */
|
||||
boolean_t is_reset_pending;
|
||||
boolean_t is_channel_running;
|
||||
|
||||
Loading…
Reference in New Issue
Block a user