Files
linux-nvgpu/drivers/gpu/nvgpu/common/sync/channel_sync_syncpt.c
Konsta Hölttä 52835c39ae gpu: nvgpu: do not skip completed syncpt prefences
A corner case has existed since ancient times for syncpoint-backed
prefences to not cause a gpu wait if the fence is found to be completed
in the submit path. This adds some unnecessary complexity, so don't
check for completion in software. Let the gpu "wait" for these
known-to-be-trivial waits too. Necessary priv cmdbuf space has been
allocated anyway.

Originally nvhost had 16-bit fences which would wrap around relatively
quickly, so waiting for an old fence could have looked like waiting for
a fence that will expire long in the future. With 32-bit thresholds,
this hasn't been the case for several Tegra generations anymore, and
nvhost doesn't ignore waits like this either.

The wait priv cmdbuf in submit path can still be missing even with a
prefence supplied because the Android sync framework supports sync fds
that contain zero fences inside; this can happen at least when merging
fences that have all been expired. In such conditions the wait cmdbuf
wouldn't even get allocated.

[this is squashed with commit 8b3b0cb12d118 (gpu: nvgpu: allow no wait
cmd with valid input fence) from
https://git-master.nvidia.com/r/c/linux-nvgpu/+/2325677]

Jira NVGPU-4548

Change-Id: Ie81fd8735c2614d0fedb7242dc9869d0961610eb
Signed-off-by: Konsta Hölttä <kholtta@nvidia.com>
Reviewed-on: https://git-master.nvidia.com/r/c/linux-nvgpu/+/2321762
(cherry picked from commit 8f3dac44934eb727b1bf4fb853f019cf4c15a5cd)
Reviewed-on: https://git-master.nvidia.com/r/c/linux-nvgpu/+/2324254
Reviewed-by: automaticguardword <automaticguardword@nvidia.com>
Reviewed-by: svc-mobile-coverity <svc-mobile-coverity@nvidia.com>
Reviewed-by: svc-mobile-misra <svc-mobile-misra@nvidia.com>
Reviewed-by: svc-mobile-cert <svc-mobile-cert@nvidia.com>
Reviewed-by: Alex Waterman <alexw@nvidia.com>
Reviewed-by: mobile promotions <svcmobile_promotions@nvidia.com>
GVS: Gerrit_Virtual_Submit
Tested-by: mobile promotions <svcmobile_promotions@nvidia.com>
2020-12-15 14:13:28 -06:00

388 lines
10 KiB
C

/*
* GK20A Channel Synchronization Abstraction
*
* Copyright (c) 2014-2020, NVIDIA CORPORATION. All rights reserved.
*
* Permission is hereby granted, free of charge, to any person obtaining a
* copy of this software and associated documentation files (the "Software"),
* to deal in the Software without restriction, including without limitation
* the rights to use, copy, modify, merge, publish, distribute, sublicense,
* and/or sell copies of the Software, and to permit persons to whom the
* Software is furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
* DEALINGS IN THE SOFTWARE.
*/
#include <nvgpu/kmem.h>
#include <nvgpu/log.h>
#include <nvgpu/atomic.h>
#include <nvgpu/bug.h>
#include <nvgpu/list.h>
#include <nvgpu/nvhost.h>
#include <nvgpu/gk20a.h>
#include <nvgpu/os_fence.h>
#include <nvgpu/os_fence_syncpts.h>
#include <nvgpu/channel.h>
#include <nvgpu/channel_sync.h>
#include <nvgpu/channel_sync_syncpt.h>
#include <nvgpu/fence.h>
#include <nvgpu/string.h>
#include "channel_sync_priv.h"
struct nvgpu_channel_sync_syncpt {
struct nvgpu_channel_sync base;
struct nvgpu_channel *c;
struct nvgpu_nvhost_dev *nvhost;
u32 id;
struct nvgpu_mem syncpt_buf;
};
static struct nvgpu_channel_sync_syncpt *
nvgpu_channel_sync_syncpt_from_base(struct nvgpu_channel_sync *base)
{
return (struct nvgpu_channel_sync_syncpt *)
((uintptr_t)base -
offsetof(struct nvgpu_channel_sync_syncpt, base));
}
static int channel_sync_syncpt_gen_wait_cmd(struct nvgpu_channel *c,
u32 id, u32 thresh, struct priv_cmd_entry *wait_cmd,
u32 wait_cmd_size, u32 pos, bool preallocated)
{
int err = 0;
if (!preallocated) {
err = nvgpu_channel_alloc_priv_cmdbuf(c,
c->g->ops.sync.syncpt.get_wait_cmd_size(),
wait_cmd);
if (err != 0) {
nvgpu_err(c->g, "not enough priv cmd buffer space");
return err;
}
}
nvgpu_log(c->g, gpu_dbg_info, "sp->id %d gpu va %llx",
id, c->vm->syncpt_ro_map_gpu_va);
c->g->ops.sync.syncpt.add_wait_cmd(c->g, wait_cmd,
pos * wait_cmd_size, id, thresh,
c->vm->syncpt_ro_map_gpu_va);
return 0;
}
static int channel_sync_syncpt_wait_raw(struct nvgpu_channel_sync_syncpt *s,
u32 id, u32 thresh, struct priv_cmd_entry *wait_cmd)
{
struct nvgpu_channel *c = s->c;
int err = 0;
u32 wait_cmd_size = c->g->ops.sync.syncpt.get_wait_cmd_size();
if (!nvgpu_nvhost_syncpt_is_valid_pt_ext(s->nvhost, id)) {
return -EINVAL;
}
err = channel_sync_syncpt_gen_wait_cmd(c, id, thresh,
wait_cmd, wait_cmd_size, 0, false);
return err;
}
static int channel_sync_syncpt_wait_fd(struct nvgpu_channel_sync *s, int fd,
struct priv_cmd_entry *wait_cmd, u32 max_wait_cmds)
{
struct nvgpu_os_fence os_fence = {0};
struct nvgpu_os_fence_syncpt os_fence_syncpt = {0};
struct nvgpu_channel_sync_syncpt *sp =
nvgpu_channel_sync_syncpt_from_base(s);
struct nvgpu_channel *c = sp->c;
int err = 0;
u32 i, num_fences, wait_cmd_size;
u32 syncpt_id = 0U;
u32 syncpt_thresh = 0U;
err = nvgpu_os_fence_fdget(&os_fence, c, fd);
if (err != 0) {
return -EINVAL;
}
err = nvgpu_os_fence_get_syncpts(&os_fence_syncpt, &os_fence);
if (err != 0) {
goto cleanup;
}
num_fences = nvgpu_os_fence_syncpt_get_num_syncpoints(&os_fence_syncpt);
if (num_fences == 0U) {
goto cleanup;
}
if ((max_wait_cmds != 0U) && (num_fences > max_wait_cmds)) {
err = -EINVAL;
goto cleanup;
}
for (i = 0; i < num_fences; i++) {
nvgpu_os_fence_syncpt_extract_nth_syncpt(
&os_fence_syncpt, i, &syncpt_id, &syncpt_thresh);
if ((syncpt_id == 0U) || !nvgpu_nvhost_syncpt_is_valid_pt_ext(
c->g->nvhost, syncpt_id)) {
err = -EINVAL;
goto cleanup;
}
}
wait_cmd_size = c->g->ops.sync.syncpt.get_wait_cmd_size();
err = nvgpu_channel_alloc_priv_cmdbuf(c,
wait_cmd_size * num_fences, wait_cmd);
if (err != 0) {
nvgpu_err(c->g, "not enough priv cmd buffer space");
err = -EINVAL;
goto cleanup;
}
for (i = 0; i < num_fences; i++) {
nvgpu_os_fence_syncpt_extract_nth_syncpt(
&os_fence_syncpt, i, &syncpt_id, &syncpt_thresh);
err = channel_sync_syncpt_gen_wait_cmd(c, syncpt_id,
syncpt_thresh, wait_cmd, wait_cmd_size, i, true);
}
cleanup:
os_fence.ops->drop_ref(&os_fence);
return err;
}
static void channel_sync_syncpt_update(void *priv, int nr_completed)
{
struct nvgpu_channel *ch = priv;
nvgpu_channel_update(ch);
/* note: channel_get() is in channel_sync_syncpt_incr_common() */
nvgpu_channel_put(ch);
}
static int channel_sync_syncpt_incr_common(struct nvgpu_channel_sync *s,
bool wfi_cmd,
bool register_irq,
struct priv_cmd_entry *incr_cmd,
struct nvgpu_fence_type *fence,
bool need_sync_fence)
{
u32 thresh;
int err;
struct nvgpu_channel_sync_syncpt *sp =
nvgpu_channel_sync_syncpt_from_base(s);
struct nvgpu_channel *c = sp->c;
struct nvgpu_os_fence os_fence = {0};
err = nvgpu_channel_alloc_priv_cmdbuf(c,
c->g->ops.sync.syncpt.get_incr_cmd_size(wfi_cmd),
incr_cmd);
if (err != 0) {
return err;
}
nvgpu_log(c->g, gpu_dbg_info, "sp->id %d gpu va %llx",
sp->id, sp->syncpt_buf.gpu_va);
c->g->ops.sync.syncpt.add_incr_cmd(c->g, wfi_cmd,
incr_cmd, sp->id, sp->syncpt_buf.gpu_va);
thresh = nvgpu_nvhost_syncpt_incr_max_ext(sp->nvhost, sp->id,
c->g->ops.sync.syncpt.get_incr_per_release());
if (register_irq) {
struct nvgpu_channel *referenced = nvgpu_channel_get(c);
WARN_ON(!referenced);
if (referenced) {
/* note: channel_put() is in
* channel_sync_syncpt_update() */
err = nvgpu_nvhost_intr_register_notifier(
sp->nvhost,
sp->id, thresh,
channel_sync_syncpt_update, c);
if (err != 0) {
nvgpu_channel_put(referenced);
}
/* Adding interrupt action should
* never fail. A proper error handling
* here would require us to decrement
* the syncpt max back to its original
* value. */
WARN(err,
"failed to set submit complete interrupt");
}
}
if (need_sync_fence) {
err = nvgpu_os_fence_syncpt_create(&os_fence, c, sp->nvhost,
sp->id, thresh);
if (err != 0) {
goto clean_up_priv_cmd;
}
}
err = nvgpu_fence_from_syncpt(fence, sp->nvhost,
sp->id, thresh, os_fence);
if (err != 0) {
if (nvgpu_os_fence_is_initialized(&os_fence) != 0) {
os_fence.ops->drop_ref(&os_fence);
}
goto clean_up_priv_cmd;
}
return 0;
clean_up_priv_cmd:
nvgpu_channel_update_priv_cmd_q_and_free_entry(c, incr_cmd);
return err;
}
static int channel_sync_syncpt_incr(struct nvgpu_channel_sync *s,
struct priv_cmd_entry *entry,
struct nvgpu_fence_type *fence,
bool need_sync_fence,
bool register_irq)
{
/* Don't put wfi cmd to this one since we're not returning
* a fence to user space. */
return channel_sync_syncpt_incr_common(s,
false /* no wfi */,
register_irq /* register irq */,
entry, fence, need_sync_fence);
}
static int channel_sync_syncpt_incr_user(struct nvgpu_channel_sync *s,
int wait_fence_fd,
struct priv_cmd_entry *entry,
struct nvgpu_fence_type *fence,
bool wfi,
bool need_sync_fence,
bool register_irq)
{
/* Need to do 'wfi + host incr' since we return the fence
* to user space. */
return channel_sync_syncpt_incr_common(s,
wfi,
register_irq /* register irq */,
entry, fence, need_sync_fence);
}
int nvgpu_channel_sync_wait_syncpt(struct nvgpu_channel_sync_syncpt *s,
u32 id, u32 thresh, struct priv_cmd_entry *entry)
{
return channel_sync_syncpt_wait_raw(s, id, thresh, entry);
}
static void channel_sync_syncpt_set_min_eq_max(struct nvgpu_channel_sync *s)
{
struct nvgpu_channel_sync_syncpt *sp =
nvgpu_channel_sync_syncpt_from_base(s);
nvgpu_nvhost_syncpt_set_min_eq_max_ext(sp->nvhost, sp->id);
}
static u32 channel_sync_syncpt_get_id(struct nvgpu_channel_sync_syncpt *sp)
{
return sp->id;
}
static void channel_sync_syncpt_destroy(struct nvgpu_channel_sync *s)
{
struct nvgpu_channel_sync_syncpt *sp =
nvgpu_channel_sync_syncpt_from_base(s);
sp->c->g->ops.sync.syncpt.free_buf(sp->c, &sp->syncpt_buf);
nvgpu_nvhost_syncpt_set_min_eq_max_ext(sp->nvhost, sp->id);
nvgpu_nvhost_syncpt_put_ref_ext(sp->nvhost, sp->id);
nvgpu_kfree(sp->c->g, sp);
}
u32 nvgpu_channel_sync_get_syncpt_id(struct nvgpu_channel_sync_syncpt *s)
{
return channel_sync_syncpt_get_id(s);
}
static const struct nvgpu_channel_sync_ops channel_sync_syncpt_ops = {
.wait_fence_fd = channel_sync_syncpt_wait_fd,
.incr = channel_sync_syncpt_incr,
.incr_user = channel_sync_syncpt_incr_user,
.set_min_eq_max = channel_sync_syncpt_set_min_eq_max,
.destroy = channel_sync_syncpt_destroy,
};
struct nvgpu_channel_sync_syncpt *
nvgpu_channel_sync_to_syncpt(struct nvgpu_channel_sync *sync)
{
struct nvgpu_channel_sync_syncpt *syncpt = NULL;
if (sync->ops == &channel_sync_syncpt_ops) {
syncpt = nvgpu_channel_sync_syncpt_from_base(sync);
}
return syncpt;
}
struct nvgpu_channel_sync *
nvgpu_channel_sync_syncpt_create(struct nvgpu_channel *c)
{
struct nvgpu_channel_sync_syncpt *sp;
char syncpt_name[32];
int err;
sp = nvgpu_kzalloc(c->g, sizeof(*sp));
if (sp == NULL) {
return NULL;
}
sp->c = c;
sp->nvhost = c->g->nvhost;
snprintf(syncpt_name, sizeof(syncpt_name),
"%s_%d", c->g->name, c->chid);
sp->id = nvgpu_nvhost_get_syncpt_host_managed(sp->nvhost,
c->chid, syncpt_name);
if (sp->id == 0U) {
nvgpu_kfree(c->g, sp);
nvgpu_err(c->g, "failed to get free syncpt");
return NULL;
}
err = sp->c->g->ops.sync.syncpt.alloc_buf(sp->c, sp->id,
&sp->syncpt_buf);
if (err != 0) {
nvgpu_nvhost_syncpt_put_ref_ext(sp->nvhost, sp->id);
nvgpu_kfree(c->g, sp);
nvgpu_err(c->g, "failed to allocate syncpoint buffer");
return NULL;
}
nvgpu_nvhost_syncpt_set_min_eq_max_ext(sp->nvhost, sp->id);
nvgpu_atomic_set(&sp->base.refcount, 0);
sp->base.ops = &channel_sync_syncpt_ops;
return &sp->base;
}