On 14.07.2022 14:06, Mauro Carvalho Chehab wrote: > From: Prathap Kumar Valsan <prathap.kumar.valsan@xxxxxxxxx> > > Add routines to interface with GuC firmware for TLB invalidation. > > Signed-off-by: Prathap Kumar Valsan <prathap.kumar.valsan@xxxxxxxxx> > Cc: Bruce Chang <yu.bruce.chang@xxxxxxxxx> > Cc: Michal Wajdeczko <michal.wajdeczko@xxxxxxxxx> > Cc: Matthew Brost <matthew.brost@xxxxxxxxx> > Cc: Chris Wilson <chris.p.wilson@xxxxxxxxx> > Signed-off-by: Mauro Carvalho Chehab <mchehab@xxxxxxxxxx> > --- > > To avoid mailbombing on a large number of people, only mailing lists were C/C on the cover. > See [PATCH v2 00/21] at: https://lore.kernel.org/all/cover.1657800199.git.mchehab@xxxxxxxxxx/ > > .../gpu/drm/i915/gt/uc/abi/guc_actions_abi.h | 35 +++++++ > drivers/gpu/drm/i915/gt/uc/intel_guc.c | 90 ++++++++++++++++++ > drivers/gpu/drm/i915/gt/uc/intel_guc.h | 13 +++ > drivers/gpu/drm/i915/gt/uc/intel_guc_ct.c | 24 ++++- > drivers/gpu/drm/i915/gt/uc/intel_guc_fwif.h | 6 ++ > .../gpu/drm/i915/gt/uc/intel_guc_submission.c | 91 ++++++++++++++++++- > 6 files changed, 253 insertions(+), 6 deletions(-) > > diff --git a/drivers/gpu/drm/i915/gt/uc/abi/guc_actions_abi.h b/drivers/gpu/drm/i915/gt/uc/abi/guc_actions_abi.h > index 4ef9990ed7f8..2e39d8df4c82 100644 > --- a/drivers/gpu/drm/i915/gt/uc/abi/guc_actions_abi.h > +++ b/drivers/gpu/drm/i915/gt/uc/abi/guc_actions_abi.h > @@ -134,6 +134,10 @@ enum intel_guc_action { > INTEL_GUC_ACTION_REGISTER_CONTEXT_MULTI_LRC = 0x4601, > INTEL_GUC_ACTION_CLIENT_SOFT_RESET = 0x5507, > INTEL_GUC_ACTION_SET_ENG_UTIL_BUFF = 0x550A, > + INTEL_GUC_ACTION_NOTIFY_MEMORY_CAT_ERROR = 0x6000, should this be part of this patch ? > + INTEL_GUC_ACTION_PAGE_FAULT_NOTIFICATION = 0x6001, > + INTEL_GUC_ACTION_TLB_INVALIDATION = 0x7000, > + INTEL_GUC_ACTION_TLB_INVALIDATION_DONE = 0x7001, can we document layout of these actions ? > INTEL_GUC_ACTION_STATE_CAPTURE_NOTIFICATION = 0x8002, > INTEL_GUC_ACTION_NOTIFY_FLUSH_LOG_BUFFER_TO_FILE = 0x8003, > INTEL_GUC_ACTION_NOTIFY_CRASH_DUMP_POSTED = 0x8004, > @@ -177,4 +181,35 @@ enum intel_guc_state_capture_event_status { > > #define INTEL_GUC_STATE_CAPTURE_EVENT_STATUS_MASK 0x000000FF > > +#define INTEL_GUC_TLB_INVAL_TYPE_SHIFT 0 > +#define INTEL_GUC_TLB_INVAL_MODE_SHIFT 8 can we stop using SHIFT-based definitions and start using MASK-based instead ? then we will be able to use FIELD_PREP/GET like we do for i915_reg > +/* Flush PPC or SMRO caches along with TLB invalidation request */ > +#define INTEL_GUC_TLB_INVAL_FLUSH_CACHE (1 << 31) > + > +enum intel_guc_tlb_invalidation_type { > + INTEL_GUC_TLB_INVAL_GUC = 0x3, > +}; > + > +/* > + * 0: Heavy mode of Invalidation: > + * The pipeline of the engine(s) for which the invalidation is targeted to is > + * blocked, and all the in-flight transactions are guaranteed to be Globally > + * Observed before completing the TLB invalidation > + * 1: Lite mode of Invalidation: > + * TLBs of the targeted engine(s) are immediately invalidated. > + * In-flight transactions are NOT guaranteed to be Globally Observed before > + * completing TLB invalidation. > + * Light Invalidation Mode is to be used only when > + * it can be guaranteed (by SW) that the address translations remain invariant > + * for the in-flight transactions across the TLB invalidation. In other words, > + * this mode can be used when the TLB invalidation is intended to clear out the > + * stale cached translations that are no longer in use. Light Invalidation Mode > + * is much faster than the Heavy Invalidation Mode, as it does not wait for the > + * in-flight transactions to be GOd. > + */ either drop this comment or squash with patch 10/21 to fix it > +enum intel_guc_tlb_inval_mode { > + INTEL_GUC_TLB_INVAL_MODE_HEAVY = 0x0, > + INTEL_GUC_TLB_INVAL_MODE_LITE = 0x1, > +}; > + > #endif /* _ABI_GUC_ACTIONS_ABI_H */ > diff --git a/drivers/gpu/drm/i915/gt/uc/intel_guc.c b/drivers/gpu/drm/i915/gt/uc/intel_guc.c > index 2706a8c65090..5c59f9b144a3 100644 > --- a/drivers/gpu/drm/i915/gt/uc/intel_guc.c > +++ b/drivers/gpu/drm/i915/gt/uc/intel_guc.c > @@ -855,6 +855,96 @@ int intel_guc_self_cfg64(struct intel_guc *guc, u16 key, u64 value) > return __guc_self_cfg(guc, key, 2, value); > } > > +static int guc_send_invalidate_tlb(struct intel_guc *guc, u32 *action, u32 size) nit: maybe since MMIO TLB has moved to dedicated file, we can do the same with GUC TLB code like "intel_guc_tlb.c" ? > +{ > + struct intel_guc_tlb_wait _wq, *wq = &_wq; > + DEFINE_WAIT_FUNC(wait, woken_wake_function); > + int err = 0; > + u32 seqno; > + > + init_waitqueue_head(&_wq.wq); > + > + if (xa_alloc_cyclic_irq(&guc->tlb_lookup, &seqno, wq, > + xa_limit_32b, &guc->next_seqno, > + GFP_ATOMIC | __GFP_NOWARN) < 0) { > + /* Under severe memory pressure? Serialise TLB allocations */ > + xa_lock_irq(&guc->tlb_lookup); > + wq = xa_load(&guc->tlb_lookup, guc->serial_slot); > + wait_event_lock_irq(wq->wq, > + !READ_ONCE(wq->status), > + guc->tlb_lookup.xa_lock); > + /* > + * Update wq->status under lock to ensure only one waiter can > + * issue the tlb invalidation command using the serial slot at a > + * time. The condition is set to false before releasing the lock > + * so that other caller continue to wait until woken up again. > + */ > + wq->status = 1; > + xa_unlock_irq(&guc->tlb_lookup); > + > + seqno = guc->serial_slot; > + } > + > + action[1] = seqno; it's sad that we need to update in blind this action message if you don't want to expose seqno allocation in a helper function that each caller would use, then maybe assert that this action message is expected one > + > + add_wait_queue(&wq->wq, &wait); > + > + err = intel_guc_send_busy_loop(guc, action, size, G2H_LEN_DW_INVALIDATE_TLB, true); > + if (err) { > + /* > + * XXX: Failure of tlb invalidation is critical and would s/tlb/TLB > + * warrant a gt reset. > + */ > + goto out; > + } > +/* > + * GuC has a timeout of 1ms for a tlb invalidation response from GAM. On a ditto > + * timeout GuC drops the request and has no mechanism to notify the host about > + * the timeout. So keep a larger timeout that accounts for this individual > + * timeout and max number of outstanding invalidation requests that can be > + * queued in CT buffer. > + */ > +#define OUTSTANDING_GUC_TIMEOUT_PERIOD (HZ) > + if (!wait_woken(&wait, TASK_UNINTERRUPTIBLE, IIRC there was some discussion if we can rely on this in our scenario can you sync with Chris on that? > + OUTSTANDING_GUC_TIMEOUT_PERIOD)) { > + /* > + * XXX: Failure of tlb invalidation is critical and would s/tlb/TLB > + * warrant a gt reset. > + */ > + drm_err(&guc_to_gt(guc)->i915->drm, > + "tlb invalidation response timed out for seqno %u\n", seqno); s/tlb/TLB btw, should we care here about G2H_LEN_DW_INVALIDATE_TLB space that we reserved in send_busy_loop() ? > + err = -ETIME; > + } > +out: > + remove_wait_queue(&wq->wq, &wait); > + if (seqno != guc->serial_slot) > + xa_erase_irq(&guc->tlb_lookup, seqno); > + > + return err; > +} > + > +/* > + * Guc TLB Invalidation: Invalidate the TLB's of GuC itself. > + */ > +int intel_guc_invalidate_tlb_guc(struct intel_guc *guc, > + enum intel_guc_tlb_inval_mode mode) > +{ > + u32 action[] = { > + INTEL_GUC_ACTION_TLB_INVALIDATION, > + 0, > + INTEL_GUC_TLB_INVAL_GUC << INTEL_GUC_TLB_INVAL_TYPE_SHIFT | > + mode << INTEL_GUC_TLB_INVAL_MODE_SHIFT | > + INTEL_GUC_TLB_INVAL_FLUSH_CACHE, > + }; > + > + if (!INTEL_GUC_SUPPORTS_TLB_INVALIDATION(guc)) { > + DRM_ERROR("Tlb invalidation: Operation not supported in this platform!\n"); you should use drm_err() instead but wondering if maybe this should be treated as a coding error (and then use GEM_BUG/WARN_ON instead) but then not sure how to interpret the check for the intel_guc_ct_enabled() embedded in above macro ... note that intel_guc_ct_send() will return -ENODEV if CTB is down > + return 0; > + } > + > + return guc_send_invalidate_tlb(guc, action, ARRAY_SIZE(action)); > +} > + > /** > * intel_guc_load_status - dump information about GuC load status > * @guc: the GuC > diff --git a/drivers/gpu/drm/i915/gt/uc/intel_guc.h b/drivers/gpu/drm/i915/gt/uc/intel_guc.h > index d0d99f178f2d..f82a121b0838 100644 > --- a/drivers/gpu/drm/i915/gt/uc/intel_guc.h > +++ b/drivers/gpu/drm/i915/gt/uc/intel_guc.h > @@ -77,6 +77,10 @@ struct intel_guc { > atomic_t outstanding_submission_g2h; > > /** @interrupts: pointers to GuC interrupt-managing functions. */ > + struct xarray tlb_lookup; > + u32 serial_slot; > + u32 next_seqno; wrong place - above kernel-doc is for the struct below > + > struct { > void (*reset)(struct intel_guc *guc); > void (*enable)(struct intel_guc *guc); > @@ -248,6 +252,11 @@ struct intel_guc { > #endif > }; > > +struct intel_guc_tlb_wait { > + struct wait_queue_head wq; > + u8 status; > +} __aligned(4); > + > static inline struct intel_guc *log_to_guc(struct intel_guc_log *log) > { > return container_of(log, struct intel_guc, log); > @@ -363,6 +372,9 @@ int intel_guc_allocate_and_map_vma(struct intel_guc *guc, u32 size, > int intel_guc_self_cfg32(struct intel_guc *guc, u16 key, u32 value); > int intel_guc_self_cfg64(struct intel_guc *guc, u16 key, u64 value); > > +int intel_guc_invalidate_tlb_guc(struct intel_guc *guc, > + enum intel_guc_tlb_inval_mode mode); > + > static inline bool intel_guc_is_supported(struct intel_guc *guc) > { > return intel_uc_fw_is_supported(&guc->fw); > @@ -440,6 +452,7 @@ int intel_guc_engine_failure_process_msg(struct intel_guc *guc, > const u32 *msg, u32 len); > int intel_guc_error_capture_process_msg(struct intel_guc *guc, > const u32 *msg, u32 len); > +void intel_guc_tlb_invalidation_done(struct intel_guc *guc, u32 seqno); > > struct intel_engine_cs * > intel_guc_lookup_engine(struct intel_guc *guc, u8 guc_class, u8 instance); > diff --git a/drivers/gpu/drm/i915/gt/uc/intel_guc_ct.c b/drivers/gpu/drm/i915/gt/uc/intel_guc_ct.c > index f01325cd1b62..c1ce542b7855 100644 > --- a/drivers/gpu/drm/i915/gt/uc/intel_guc_ct.c > +++ b/drivers/gpu/drm/i915/gt/uc/intel_guc_ct.c > @@ -1023,7 +1023,7 @@ static int ct_process_request(struct intel_guc_ct *ct, struct ct_incoming_msg *r > return 0; > } > > -static bool ct_process_incoming_requests(struct intel_guc_ct *ct) > +static bool ct_process_incoming_requests(struct intel_guc_ct *ct, struct list_head *incoming) > { > unsigned long flags; > struct ct_incoming_msg *request; > @@ -1031,11 +1031,11 @@ static bool ct_process_incoming_requests(struct intel_guc_ct *ct) > int err; > > spin_lock_irqsave(&ct->requests.lock, flags); > - request = list_first_entry_or_null(&ct->requests.incoming, > + request = list_first_entry_or_null(incoming, > struct ct_incoming_msg, link); > if (request) > list_del(&request->link); > - done = !!list_empty(&ct->requests.incoming); > + done = !!list_empty(incoming); > spin_unlock_irqrestore(&ct->requests.lock, flags); > > if (!request) > @@ -1058,7 +1058,7 @@ static void ct_incoming_request_worker_func(struct work_struct *w) > bool done; > > do { > - done = ct_process_incoming_requests(ct); > + done = ct_process_incoming_requests(ct, &ct->requests.incoming); > } while (!done); > } > > @@ -1078,14 +1078,30 @@ static int ct_handle_event(struct intel_guc_ct *ct, struct ct_incoming_msg *requ > switch (action) { > case INTEL_GUC_ACTION_SCHED_CONTEXT_MODE_DONE: > case INTEL_GUC_ACTION_DEREGISTER_CONTEXT_DONE: > + case INTEL_GUC_ACTION_TLB_INVALIDATION_DONE: > g2h_release_space(ct, request->size); > } > + /* Handle tlb invalidation response in interrupt context */ since it breaks layering, can you add more comments why this is done in such way ? > + if (action == INTEL_GUC_ACTION_TLB_INVALIDATION_DONE) { > + const u32 *payload; > + u32 hxg_len, len; > + > + hxg_len = request->size - GUC_CTB_MSG_MIN_LEN; > + len = hxg_len - GUC_HXG_MSG_MIN_LEN; > + if (unlikely(len < 1)) > + return -EPROTO; > + payload = &hxg[GUC_HXG_MSG_MIN_LEN]; if we still need to handle this at this level, can we at least move this message decomposition to the handler (in other words: just pass hxg pointer instead of single dword payload) > + intel_guc_tlb_invalidation_done(ct_to_guc(ct), payload[0]); > + ct_free_msg(request); > + return 0; > + } > > spin_lock_irqsave(&ct->requests.lock, flags); > list_add_tail(&request->link, &ct->requests.incoming); > spin_unlock_irqrestore(&ct->requests.lock, flags); > > queue_work(system_unbound_wq, &ct->requests.worker); > + > return 0; > } > > diff --git a/drivers/gpu/drm/i915/gt/uc/intel_guc_fwif.h b/drivers/gpu/drm/i915/gt/uc/intel_guc_fwif.h > index b3c9a9327f76..3edf567b3f65 100644 > --- a/drivers/gpu/drm/i915/gt/uc/intel_guc_fwif.h > +++ b/drivers/gpu/drm/i915/gt/uc/intel_guc_fwif.h > @@ -22,6 +22,7 @@ > /* Payload length only i.e. don't include G2H header length */ > #define G2H_LEN_DW_SCHED_CONTEXT_MODE_SET 2 > #define G2H_LEN_DW_DEREGISTER_CONTEXT 1 > +#define G2H_LEN_DW_INVALIDATE_TLB 1 > > #define GUC_CONTEXT_DISABLE 0 > #define GUC_CONTEXT_ENABLE 1 > @@ -431,4 +432,9 @@ enum intel_guc_recv_message { > INTEL_GUC_RECV_MSG_EXCEPTION = BIT(30), > }; > > +#define INTEL_GUC_SUPPORTS_TLB_INVALIDATION(guc) \ > + ((intel_guc_ct_enabled(&(guc)->ct)) && \ do we need this check ? CTB is prerequisite for submission that is required below > + (intel_guc_submission_is_used(guc)) && \ > + (GRAPHICS_VER(guc_to_gt((guc))->i915) >= 12)) > + > #endif > diff --git a/drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c b/drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c > index 40f726c61e95..6888ea1bc7c1 100644 > --- a/drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c > +++ b/drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c > @@ -1653,11 +1653,20 @@ static void __guc_reset_context(struct intel_context *ce, intel_engine_mask_t st > intel_context_put(parent); > } > > +static void wake_up_tlb_invalidate(struct intel_guc_tlb_wait *wait) > +{ > + /* Barrier to ensure the store is observed by the woken thread */ > + smp_store_mb(wait->status, 0); > + wake_up(&wait->wq); > +} > + > void intel_guc_submission_reset(struct intel_guc *guc, intel_engine_mask_t stalled) > { > + struct intel_guc_tlb_wait *wait; > struct intel_context *ce; > unsigned long index; > unsigned long flags; > + unsigned long i; > > if (unlikely(!guc_submission_initialized(guc))) { > /* Reset called during driver load? GuC not yet initialised! */ > @@ -1683,6 +1692,13 @@ void intel_guc_submission_reset(struct intel_guc *guc, intel_engine_mask_t stall > > /* GuC is blown away, drop all references to contexts */ > xa_destroy(&guc->context_lookup); > + > + /* > + * The full GT reset will have cleared the TLB caches and flushed the > + * G2H message queue; we can release all the blocked waiters. > + */ > + xa_for_each(&guc->tlb_lookup, i, wait) > + wake_up_tlb_invalidate(wait); shouldn't this be closer to intel_guc_invalidate_tlb_guc() then we can avoid spreading code across many files same for the init/fini_tlb_lookup() functions below > } > > static void guc_cancel_context_requests(struct intel_context *ce) > @@ -1805,6 +1821,41 @@ void intel_guc_submission_reset_finish(struct intel_guc *guc) > static void destroyed_worker_func(struct work_struct *w); > static void reset_fail_worker_func(struct work_struct *w); > > +static int init_tlb_lookup(struct intel_guc *guc) > +{ > + struct intel_guc_tlb_wait *wait; > + int err; > + > + xa_init_flags(&guc->tlb_lookup, XA_FLAGS_ALLOC); > + > + wait = kzalloc(sizeof(*wait), GFP_KERNEL); > + if (!wait) > + return -ENOMEM; > + > + init_waitqueue_head(&wait->wq); > + err = xa_alloc_cyclic_irq(&guc->tlb_lookup, &guc->serial_slot, wait, > + xa_limit_32b, &guc->next_seqno, GFP_KERNEL); > + if (err == -ENOMEM) { > + kfree(wait); > + return err; > + } > + > + return 0; > +} > + > +static void fini_tlb_lookup(struct intel_guc *guc) > +{ > + struct intel_guc_tlb_wait *wait; > + > + wait = xa_load(&guc->tlb_lookup, guc->serial_slot); > + if (wait) { > + GEM_BUG_ON(wait->status); > + kfree(wait); > + } > + > + xa_destroy(&guc->tlb_lookup); > +} > + > /* > * Set up the memory resources to be shared with the GuC (via the GGTT) > * at firmware loading time. > @@ -1812,20 +1863,31 @@ static void reset_fail_worker_func(struct work_struct *w); > int intel_guc_submission_init(struct intel_guc *guc) > { > struct intel_gt *gt = guc_to_gt(guc); > + int ret; > > if (guc->submission_initialized) > return 0; > > + ret = init_tlb_lookup(guc); if we promote guc_tlb to own file/functions then maybe it could be init/fini directly from __uc_init_hw() ? > + if (ret) > + return ret; > + > guc->submission_state.guc_ids_bitmap = > bitmap_zalloc(NUMBER_MULTI_LRC_GUC_ID(guc), GFP_KERNEL); > - if (!guc->submission_state.guc_ids_bitmap) > - return -ENOMEM; > + if (!guc->submission_state.guc_ids_bitmap) { > + ret = -ENOMEM; > + goto err; > + } > > guc->timestamp.ping_delay = (POLL_TIME_CLKS / gt->clock_frequency + 1) * HZ; > guc->timestamp.shift = gpm_timestamp_shift(gt); > guc->submission_initialized = true; > > return 0; > + > +err: > + fini_tlb_lookup(guc); > + return ret; > } > > void intel_guc_submission_fini(struct intel_guc *guc) > @@ -1836,6 +1898,7 @@ void intel_guc_submission_fini(struct intel_guc *guc) > guc_flush_destroyed_contexts(guc); > i915_sched_engine_put(guc->sched_engine); > bitmap_free(guc->submission_state.guc_ids_bitmap); > + fini_tlb_lookup(guc); > guc->submission_initialized = false; > } > > @@ -4027,6 +4090,30 @@ g2h_context_lookup(struct intel_guc *guc, u32 ctx_id) > return ce; > } > > +static void wait_wake_outstanding_tlb_g2h(struct intel_guc *guc, u32 seqno) > +{ > + struct intel_guc_tlb_wait *wait; > + unsigned long flags; > + > + xa_lock_irqsave(&guc->tlb_lookup, flags); > + wait = xa_load(&guc->tlb_lookup, seqno); > + > + /* We received a response after the waiting task did exit with a timeout */ > + if (unlikely(!wait)) > + drm_dbg(&guc_to_gt(guc)->i915->drm, > + "Stale tlb invalidation response with seqno %d\n", seqno); hmm, this sounds like a problem as we shouldn't get any late notifications - do we really want to hide it under drm_dbg ? > + > + if (wait) > + wake_up_tlb_invalidate(wait); > + > + xa_unlock_irqrestore(&guc->tlb_lookup, flags); > +} > + > +void intel_guc_tlb_invalidation_done(struct intel_guc *guc, u32 seqno) > +{ > + wait_wake_outstanding_tlb_g2h(guc, seqno); > +} > + > int intel_guc_deregister_done_process_msg(struct intel_guc *guc, > const u32 *msg, > u32 len) ,Michal
