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| author | Maximilian Luz <luzmaximilian@gmail.com> | 2020-12-21 19:39:54 +0100 |
|---|---|---|
| committer | Hans de Goede <hdegoede@redhat.com> | 2021-01-07 00:06:17 +0100 |
| commit | 0d21bb8560ef6bd09cab873120f940a939ad3aec (patch) | |
| tree | c8ba1a175c47fabab387bbb3aa435c85664bf612 /drivers/platform/surface/aggregator/ssh_packet_layer.c | |
| parent | 3a7081f610a0ff6385f38cf65a019383cd34bfdd (diff) | |
| download | lwn-0d21bb8560ef6bd09cab873120f940a939ad3aec.tar.gz lwn-0d21bb8560ef6bd09cab873120f940a939ad3aec.zip | |
platform/surface: aggregator: Add trace points
Add trace points to the Surface Aggregator subsystem core. These trace
points can be used to track packets, requests, and allocations. They are
further intended for debugging and testing/validation, specifically in
combination with the error injection capabilities introduced in the
subsequent commit.
Signed-off-by: Maximilian Luz <luzmaximilian@gmail.com>
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Acked-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Link: https://lore.kernel.org/r/20201221183959.1186143-5-luzmaximilian@gmail.com
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Diffstat (limited to 'drivers/platform/surface/aggregator/ssh_packet_layer.c')
| -rw-r--r-- | drivers/platform/surface/aggregator/ssh_packet_layer.c | 26 |
1 files changed, 25 insertions, 1 deletions
diff --git a/drivers/platform/surface/aggregator/ssh_packet_layer.c b/drivers/platform/surface/aggregator/ssh_packet_layer.c index 23c2e31e7d0e..c4f082e57372 100644 --- a/drivers/platform/surface/aggregator/ssh_packet_layer.c +++ b/drivers/platform/surface/aggregator/ssh_packet_layer.c @@ -26,6 +26,8 @@ #include "ssh_packet_layer.h" #include "ssh_parser.h" +#include "trace.h" + /* * To simplify reasoning about the code below, we define a few concepts. The * system below is similar to a state-machine for packets, however, there are @@ -228,6 +230,8 @@ static void __ssh_ptl_packet_release(struct kref *kref) { struct ssh_packet *p = container_of(kref, struct ssh_packet, refcnt); + trace_ssam_packet_release(p); + ptl_dbg_cond(p->ptl, "ptl: releasing packet %p\n", p); p->ops->release(p); } @@ -356,6 +360,7 @@ static int ssh_ctrl_packet_alloc(struct ssh_packet **packet, buffer->ptr = (u8 *)(*packet + 1); buffer->len = SSH_MSG_LEN_CTRL; + trace_ssam_ctrl_packet_alloc(*packet, buffer->len); return 0; } @@ -365,6 +370,7 @@ static int ssh_ctrl_packet_alloc(struct ssh_packet **packet, */ static void ssh_ctrl_packet_free(struct ssh_packet *p) { + trace_ssam_ctrl_packet_free(p); kmem_cache_free(ssh_ctrl_packet_cache, p); } @@ -398,7 +404,12 @@ static void ssh_packet_next_try(struct ssh_packet *p) lockdep_assert_held(&p->ptl->queue.lock); - p->priority = __SSH_PACKET_PRIORITY(base, try + 1); + /* + * Ensure that we write the priority in one go via WRITE_ONCE() so we + * can access it via READ_ONCE() for tracing. Note that other access + * is guarded by the queue lock, so no need to use READ_ONCE() there. + */ + WRITE_ONCE(p->priority, __SSH_PACKET_PRIORITY(base, try + 1)); } /* Must be called with queue lock held. */ @@ -560,6 +571,7 @@ static void __ssh_ptl_complete(struct ssh_packet *p, int status) { struct ssh_ptl *ptl = READ_ONCE(p->ptl); + trace_ssam_packet_complete(p, status); ptl_dbg_cond(ptl, "ptl: completing packet %p (status: %d)\n", p, status); if (p->ops->complete) @@ -1014,6 +1026,8 @@ int ssh_ptl_submit(struct ssh_ptl *ptl, struct ssh_packet *p) struct ssh_ptl *ptl_old; int status; + trace_ssam_packet_submit(p); + /* Validate packet fields. */ if (test_bit(SSH_PACKET_TY_FLUSH_BIT, &p->state)) { if (p->data.ptr || test_bit(SSH_PACKET_TY_SEQUENCED_BIT, &p->state)) @@ -1065,6 +1079,8 @@ static int __ssh_ptl_resubmit(struct ssh_packet *packet) lockdep_assert_held(&packet->ptl->pending.lock); + trace_ssam_packet_resubmit(packet); + spin_lock(&packet->ptl->queue.lock); /* Check if the packet is out of tries. */ @@ -1148,6 +1164,8 @@ void ssh_ptl_cancel(struct ssh_packet *p) if (test_and_set_bit(SSH_PACKET_SF_CANCELED_BIT, &p->state)) return; + trace_ssam_packet_cancel(p); + /* * Lock packet and commit with memory barrier. If this packet has * already been locked, it's going to be removed and completed by @@ -1202,6 +1220,8 @@ static void ssh_ptl_timeout_reap(struct work_struct *work) bool resub = false; int status; + trace_ssam_ptl_timeout_reap(atomic_read(&ptl->pending.count)); + /* * Mark reaper as "not pending". This is done before checking any * packets to avoid lost-update type problems. @@ -1224,6 +1244,8 @@ static void ssh_ptl_timeout_reap(struct work_struct *work) continue; } + trace_ssam_packet_timeout(p); + status = __ssh_ptl_resubmit(p); /* @@ -1416,6 +1438,8 @@ static size_t ssh_ptl_rx_eval(struct ssh_ptl *ptl, struct ssam_span *source) if (!frame) /* Not enough data. */ return aligned.ptr - source->ptr; + trace_ssam_rx_frame_received(frame); + switch (frame->type) { case SSH_FRAME_TYPE_ACK: ssh_ptl_acknowledge(ptl, frame->seq); |