RE: [Intel-gfx] [PATCH 3/5] drm/i915/gt: kill fetch_and_zero usage

From: Upadhyay, Tejas
Date: Mon Dec 12 2022 - 04:14:53 EST




> -----Original Message-----
> From: Intel-gfx <intel-gfx-bounces@xxxxxxxxxxxxxxxxxxxxx> On Behalf Of
> Andrzej Hajda
> Sent: Friday, December 9, 2022 9:19 PM
> To: linux-kernel@xxxxxxxxxxxxxxx; intel-gfx@xxxxxxxxxxxxxxxxxxxxx; dri-
> devel@xxxxxxxxxxxxxxxxxxxxx
> Cc: Hajda, Andrzej <andrzej.hajda@xxxxxxxxx>; Arnd Bergmann
> <arnd@xxxxxxxx>; Vivi, Rodrigo <rodrigo.vivi@xxxxxxxxx>; Andrew Morton
> <akpm@xxxxxxxxxxxxxxxxxxxx>; Andy Shevchenko
> <andriy.shevchenko@xxxxxxxxxxxxxxx>
> Subject: [Intel-gfx] [PATCH 3/5] drm/i915/gt: kill fetch_and_zero usage
>
> Better use recently introduced kernel core helper.
>
> Signed-off-by: Andrzej Hajda <andrzej.hajda@xxxxxxxxx>
> ---
> drivers/gpu/drm/i915/gt/intel_engine_cs.c | 2 +-
> drivers/gpu/drm/i915/gt/intel_engine_heartbeat.c | 4 ++--
> drivers/gpu/drm/i915/gt/intel_execlists_submission.c | 4 ++--
> drivers/gpu/drm/i915/gt/intel_ggtt.c | 4 ++--
> drivers/gpu/drm/i915/gt/intel_gsc.c | 2 +-
> drivers/gpu/drm/i915/gt/intel_gt.c | 4 ++--
> drivers/gpu/drm/i915/gt/intel_gt_pm.c | 2 +-
> drivers/gpu/drm/i915/gt/intel_lrc.c | 6 +++---
> drivers/gpu/drm/i915/gt/intel_migrate.c | 2 +-
> drivers/gpu/drm/i915/gt/intel_rc6.c | 2 +-
> drivers/gpu/drm/i915/gt/intel_rps.c | 2 +-
> drivers/gpu/drm/i915/gt/selftest_context.c | 2 +-
> drivers/gpu/drm/i915/gt/selftest_ring_submission.c | 2 +-
> drivers/gpu/drm/i915/gt/selftest_timeline.c | 2 +-
> drivers/gpu/drm/i915/gt/uc/intel_uc.c | 2 +-
> drivers/gpu/drm/i915/gt/uc/intel_uc_fw.c | 2 +-
> 16 files changed, 22 insertions(+), 22 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/gt/intel_engine_cs.c
> b/drivers/gpu/drm/i915/gt/intel_engine_cs.c
> index c33e0d72d6702b..de318d96d52abd 100644
> --- a/drivers/gpu/drm/i915/gt/intel_engine_cs.c
> +++ b/drivers/gpu/drm/i915/gt/intel_engine_cs.c
> @@ -1024,7 +1024,7 @@ static void cleanup_status_page(struct
> intel_engine_cs *engine)
> /* Prevent writes into HWSP after returning the page to the system */
> intel_engine_set_hwsp_writemask(engine, ~0u);
>
> - vma = fetch_and_zero(&engine->status_page.vma);
> + vma = exchange(&engine->status_page.vma, NULL);
> if (!vma)
> return;
>
> diff --git a/drivers/gpu/drm/i915/gt/intel_engine_heartbeat.c
> b/drivers/gpu/drm/i915/gt/intel_engine_heartbeat.c
> index 9a527e1f5be655..6029fafaaa674f 100644
> --- a/drivers/gpu/drm/i915/gt/intel_engine_heartbeat.c
> +++ b/drivers/gpu/drm/i915/gt/intel_engine_heartbeat.c
> @@ -229,7 +229,7 @@ static void heartbeat(struct work_struct *wrk)
> mutex_unlock(&ce->timeline->mutex);
> out:
> if (!engine->i915->params.enable_hangcheck ||
> !next_heartbeat(engine))
> - i915_request_put(fetch_and_zero(&engine-
> >heartbeat.systole));
> + i915_request_put(exchange(&engine->heartbeat.systole, 0));
> intel_engine_pm_put(engine);
> }
>
> @@ -244,7 +244,7 @@ void intel_engine_unpark_heartbeat(struct
> intel_engine_cs *engine) void intel_engine_park_heartbeat(struct
> intel_engine_cs *engine) {
> if (cancel_delayed_work(&engine->heartbeat.work))
> - i915_request_put(fetch_and_zero(&engine-
> >heartbeat.systole));
> + i915_request_put(exchange(&engine->heartbeat.systole, 0));
> }
>
> void intel_gt_unpark_heartbeats(struct intel_gt *gt) diff --git
> a/drivers/gpu/drm/i915/gt/intel_execlists_submission.c
> b/drivers/gpu/drm/i915/gt/intel_execlists_submission.c
> index 49a8f10d76c77b..29e78078d55a8b 100644
> --- a/drivers/gpu/drm/i915/gt/intel_execlists_submission.c
> +++ b/drivers/gpu/drm/i915/gt/intel_execlists_submission.c
> @@ -3197,7 +3197,7 @@ static void execlists_reset_cancel(struct
> intel_engine_cs *engine)
> RB_CLEAR_NODE(rb);
>
> spin_lock(&ve->base.sched_engine->lock);
> - rq = fetch_and_zero(&ve->request);
> + rq = exchange(&ve->request, NULL);
> if (rq) {
> if (i915_request_mark_eio(rq)) {
> rq->engine = engine;
> @@ -3602,7 +3602,7 @@ static void rcu_virtual_context_destroy(struct
> work_struct *wrk)
>
> spin_lock_irq(&ve->base.sched_engine->lock);
>
> - old = fetch_and_zero(&ve->request);
> + old = exchange(&ve->request, NULL);
> if (old) {
> GEM_BUG_ON(!__i915_request_is_complete(old));
> __i915_request_submit(old);
> diff --git a/drivers/gpu/drm/i915/gt/intel_ggtt.c
> b/drivers/gpu/drm/i915/gt/intel_ggtt.c
> index 0c7fe360f87331..2eb0173c6e968c 100644
> --- a/drivers/gpu/drm/i915/gt/intel_ggtt.c
> +++ b/drivers/gpu/drm/i915/gt/intel_ggtt.c
> @@ -684,7 +684,7 @@ static void fini_aliasing_ppgtt(struct i915_ggtt *ggtt) {
> struct i915_ppgtt *ppgtt;
>
> - ppgtt = fetch_and_zero(&ggtt->alias);
> + ppgtt = exchange(&ggtt->alias, NULL);
> if (!ppgtt)
> return;
>
> @@ -1238,7 +1238,7 @@ bool i915_ggtt_resume_vm(struct
> i915_address_space *vm)
> was_bound);
>
> if (obj) { /* only used during resume => exclusive access */
> - write_domain_objs |= fetch_and_zero(&obj-
> >write_domain);
> + write_domain_objs |= exchange(&obj-
> >write_domain, 0);
> obj->read_domains |= I915_GEM_DOMAIN_GTT;
> }
> }
> diff --git a/drivers/gpu/drm/i915/gt/intel_gsc.c
> b/drivers/gpu/drm/i915/gt/intel_gsc.c
> index bcc3605158dbde..7226b42bb70b2a 100644
> --- a/drivers/gpu/drm/i915/gt/intel_gsc.c
> +++ b/drivers/gpu/drm/i915/gt/intel_gsc.c
> @@ -70,7 +70,7 @@ gsc_ext_om_alloc(struct intel_gsc *gsc, struct
> intel_gsc_intf *intf, size_t size
>
> static void gsc_ext_om_destroy(struct intel_gsc_intf *intf) {
> - struct drm_i915_gem_object *obj = fetch_and_zero(&intf->gem_obj);
> + struct drm_i915_gem_object *obj = exchange(&intf->gem_obj, NULL);
>
> if (!obj)
> return;
> diff --git a/drivers/gpu/drm/i915/gt/intel_gt.c
> b/drivers/gpu/drm/i915/gt/intel_gt.c
> index 4e7af9bc73ad05..a277bd47db813e 100644
> --- a/drivers/gpu/drm/i915/gt/intel_gt.c
> +++ b/drivers/gpu/drm/i915/gt/intel_gt.c
> @@ -757,7 +757,7 @@ int intel_gt_init(struct intel_gt *gt)
> intel_uc_fini(&gt->uc);
> err_engines:
> intel_engines_release(gt);
> - i915_vm_put(fetch_and_zero(&gt->vm));
> + i915_vm_put(exchange(&gt->vm, 0));
> err_pm:
> intel_gt_pm_fini(gt);
> intel_gt_fini_scratch(gt);
> @@ -806,7 +806,7 @@ void intel_gt_driver_release(struct intel_gt *gt) {
> struct i915_address_space *vm;
>
> - vm = fetch_and_zero(&gt->vm);
> + vm = exchange(&gt->vm, NULL);
> if (vm) /* FIXME being called twice on error paths :( */
> i915_vm_put(vm);
>
> diff --git a/drivers/gpu/drm/i915/gt/intel_gt_pm.c
> b/drivers/gpu/drm/i915/gt/intel_gt_pm.c
> index 16db85fab0b19b..f066936994a9e2 100644
> --- a/drivers/gpu/drm/i915/gt/intel_gt_pm.c
> +++ b/drivers/gpu/drm/i915/gt/intel_gt_pm.c
> @@ -123,7 +123,7 @@ static int __gt_unpark(struct intel_wakeref *wf)
> static int __gt_park(struct intel_wakeref *wf) {
> struct intel_gt *gt = container_of(wf, typeof(*gt), wakeref);
> - intel_wakeref_t wakeref = fetch_and_zero(&gt->awake);
> + intel_wakeref_t wakeref = exchange(&gt->awake, 0);
> struct drm_i915_private *i915 = gt->i915;
>
> GT_TRACE(gt, "\n");
> diff --git a/drivers/gpu/drm/i915/gt/intel_lrc.c
> b/drivers/gpu/drm/i915/gt/intel_lrc.c
> index 7771a19008c604..9a2bfb6d14196c 100644
> --- a/drivers/gpu/drm/i915/gt/intel_lrc.c
> +++ b/drivers/gpu/drm/i915/gt/intel_lrc.c
> @@ -1144,7 +1144,7 @@ __lrc_alloc_state(struct intel_context *ce, struct
> intel_engine_cs *engine) static struct intel_timeline * pinned_timeline(struct
> intel_context *ce, struct intel_engine_cs *engine) {
> - struct intel_timeline *tl = fetch_and_zero(&ce->timeline);
> + struct intel_timeline *tl = exchange(&ce->timeline, NULL);
>
> return intel_timeline_create_from_engine(engine,
> page_unmask_bits(tl)); } @@ -1261,8 +1261,8 @@ void lrc_fini(struct
> intel_context *ce)
> if (!ce->state)
> return;
>
> - intel_ring_put(fetch_and_zero(&ce->ring));
> - i915_vma_put(fetch_and_zero(&ce->state));
> + intel_ring_put(exchange(&ce->ring, 0));
> + i915_vma_put(exchange(&ce->state, 0));
> }
>
> void lrc_destroy(struct kref *kref)
> diff --git a/drivers/gpu/drm/i915/gt/intel_migrate.c
> b/drivers/gpu/drm/i915/gt/intel_migrate.c
> index b405a04135ca21..2c076a51b66b30 100644
> --- a/drivers/gpu/drm/i915/gt/intel_migrate.c
> +++ b/drivers/gpu/drm/i915/gt/intel_migrate.c
> @@ -1116,7 +1116,7 @@ void intel_migrate_fini(struct intel_migrate *m) {
> struct intel_context *ce;
>
> - ce = fetch_and_zero(&m->context);
> + ce = exchange(&m->context, NULL);
> if (!ce)
> return;
>
> diff --git a/drivers/gpu/drm/i915/gt/intel_rc6.c
> b/drivers/gpu/drm/i915/gt/intel_rc6.c
> index 2ee4051e4d9613..2451ebddb0f982 100644
> --- a/drivers/gpu/drm/i915/gt/intel_rc6.c
> +++ b/drivers/gpu/drm/i915/gt/intel_rc6.c
> @@ -702,7 +702,7 @@ void intel_rc6_fini(struct intel_rc6 *rc6)
>
> intel_rc6_disable(rc6);
>
> - pctx = fetch_and_zero(&rc6->pctx);
> + pctx = exchange(&rc6->pctx, NULL);
> if (pctx)
> i915_gem_object_put(pctx);
>
> diff --git a/drivers/gpu/drm/i915/gt/intel_rps.c
> b/drivers/gpu/drm/i915/gt/intel_rps.c
> index 9ad3bc7201cbaa..a102d8768e1d7b 100644
> --- a/drivers/gpu/drm/i915/gt/intel_rps.c
> +++ b/drivers/gpu/drm/i915/gt/intel_rps.c
> @@ -1831,7 +1831,7 @@ static void rps_work(struct work_struct *work)
> u32 pm_iir = 0;
>
> spin_lock_irq(gt->irq_lock);
> - pm_iir = fetch_and_zero(&rps->pm_iir) & rps->pm_events;
> + pm_iir = exchange(&rps->pm_iir, 0) & rps->pm_events;
> client_boost = atomic_read(&rps->num_waiters);
> spin_unlock_irq(gt->irq_lock);
>
> diff --git a/drivers/gpu/drm/i915/gt/selftest_context.c
> b/drivers/gpu/drm/i915/gt/selftest_context.c
> index 76fbae358072df..ca0a38de696eec 100644
> --- a/drivers/gpu/drm/i915/gt/selftest_context.c
> +++ b/drivers/gpu/drm/i915/gt/selftest_context.c
> @@ -171,7 +171,7 @@ static int live_context_size(void *arg)
> * active state is sufficient, we are only checking that we
> * don't use more than we planned.
> */
> - saved = fetch_and_zero(&engine->default_state);
> + saved = exchange(&engine->default_state, NULL);
>
> /* Overlaps with the execlists redzone */
> engine->context_size += I915_GTT_PAGE_SIZE; diff --git
> a/drivers/gpu/drm/i915/gt/selftest_ring_submission.c
> b/drivers/gpu/drm/i915/gt/selftest_ring_submission.c
> index 87ceb0f374b673..9e901f1d5d76a9 100644
> --- a/drivers/gpu/drm/i915/gt/selftest_ring_submission.c
> +++ b/drivers/gpu/drm/i915/gt/selftest_ring_submission.c
> @@ -269,7 +269,7 @@ static int live_ctx_switch_wa(void *arg)
> if (IS_GRAPHICS_VER(gt->i915, 4, 5))
> continue; /* MI_STORE_DWORD is privileged! */
>
> - saved_wa = fetch_and_zero(&engine->wa_ctx.vma);
> + saved_wa = exchange(&engine->wa_ctx.vma, NULL);
>
> intel_engine_pm_get(engine);
> err = __live_ctx_switch_wa(engine);
> diff --git a/drivers/gpu/drm/i915/gt/selftest_timeline.c
> b/drivers/gpu/drm/i915/gt/selftest_timeline.c
> index 522d0190509ccc..d74b13b1b38a6e 100644
> --- a/drivers/gpu/drm/i915/gt/selftest_timeline.c
> +++ b/drivers/gpu/drm/i915/gt/selftest_timeline.c
> @@ -892,7 +892,7 @@ static int create_watcher(struct hwsp_watcher *w,
> static int check_watcher(struct hwsp_watcher *w, const char *name,
> bool (*op)(u32 hwsp, u32 seqno))
> {
> - struct i915_request *rq = fetch_and_zero(&w->rq);
> + struct i915_request *rq = exchange(&w->rq, NULL);
> u32 offset, end;
> int err;
>
> diff --git a/drivers/gpu/drm/i915/gt/uc/intel_uc.c
> b/drivers/gpu/drm/i915/gt/uc/intel_uc.c
> index 4f4b519e12c1b7..0085b1727dd47a 100644
> --- a/drivers/gpu/drm/i915/gt/uc/intel_uc.c
> +++ b/drivers/gpu/drm/i915/gt/uc/intel_uc.c
> @@ -166,7 +166,7 @@ static void __uc_capture_load_err_log(struct intel_uc
> *uc)
>
> static void __uc_free_load_err_log(struct intel_uc *uc) {
> - struct drm_i915_gem_object *log = fetch_and_zero(&uc-
> >load_err_log);
> + struct drm_i915_gem_object *log = exchange(&uc->load_err_log,
> NULL);
>
> if (log)
> i915_gem_object_put(log);
> diff --git a/drivers/gpu/drm/i915/gt/uc/intel_uc_fw.c
> b/drivers/gpu/drm/i915/gt/uc/intel_uc_fw.c
> index 6c83a8b66c9e32..44ff6da26bd698 100644
> --- a/drivers/gpu/drm/i915/gt/uc/intel_uc_fw.c
> +++ b/drivers/gpu/drm/i915/gt/uc/intel_uc_fw.c
> @@ -1055,7 +1055,7 @@ void intel_uc_fw_cleanup_fetch(struct intel_uc_fw
> *uc_fw)
> if (!intel_uc_fw_is_available(uc_fw))
> return;
>
> - i915_gem_object_put(fetch_and_zero(&uc_fw->obj));
> + i915_gem_object_put(exchange(&uc_fw->obj, 0));

Should this be set to NULL instead?

Thanks,
Tejas
>
> intel_uc_fw_change_status(uc_fw,
> INTEL_UC_FIRMWARE_SELECTED); }
> --
> 2.34.1