Commit 44ece225 authored by Matthew Brost's avatar Matthew Brost
Browse files

drm/xe: Do not forward invalid TLB invalidation seqnos to upper layers 



Certain TLB invalidation operations send multiple H2G messages per seqno
with only the final H2G containing the valid seqno - the others carry an
invalid seqno. The G2H handler drops these invalid seqno to aovid
prematurely signaling a TLB invalidation fence.

With TLB_INVALIDATION_SEQNO_INVALID used to indicate in progress
multi-step TLB invalidations, reset tdr to ensure that timeout
won't prematurely trigger when G2H actions are still ongoing.

v2: Remove lock from xe_tlb_inval_reset_timeout. (Matthew B)

v3: Squash with dependent patch from Matthew Brost' series.

Signed-off-by: default avatarBrian Nguyen <brian3.nguyen@intel.com>
Reviewed-by: default avatarMatthew Brost <matthew.brost@intel.com>
Signed-off-by: default avatarMatthew Brost <matthew.brost@intel.com>
Link: https://patch.msgid.link/20251212213225.3564537-13-brian3.nguyen@intel.com
parent 825aed03

drivers/gpu/drm/xe/xe_tlb_inval.c

+20 −0
Original line number Diff line number Diff line
@@ -199,6 +199,20 @@ void xe_tlb_inval_reset(struct xe_tlb_inval *tlb_inval) 
	mutex_unlock(&tlb_inval->seqno_lock);

}



/**

 * xe_tlb_inval_reset_timeout() - Reset TLB inval fence timeout

 * @tlb_inval: TLB invalidation client

 *

 * Reset the TLB invalidation timeout timer.

 */

static void xe_tlb_inval_reset_timeout(struct xe_tlb_inval *tlb_inval)

{

	lockdep_assert_held(&tlb_inval->pending_lock);



	mod_delayed_work(system_wq, &tlb_inval->fence_tdr,

			 tlb_inval->ops->timeout_delay(tlb_inval));

}



static bool xe_tlb_inval_seqno_past(struct xe_tlb_inval *tlb_inval, int seqno)

{

	int seqno_recv = READ_ONCE(tlb_inval->seqno_recv);
@@ -360,6 +374,12 @@ void xe_tlb_inval_done_handler(struct xe_tlb_inval *tlb_inval, int seqno) 
	 * process_g2h_msg().

	 */

	spin_lock_irqsave(&tlb_inval->pending_lock, flags);

	if (seqno == TLB_INVALIDATION_SEQNO_INVALID) {

		xe_tlb_inval_reset_timeout(tlb_inval);

		spin_unlock_irqrestore(&tlb_inval->pending_lock, flags);

		return;

	}



	if (xe_tlb_inval_seqno_past(tlb_inval, seqno)) {

		spin_unlock_irqrestore(&tlb_inval->pending_lock, flags);

		return;

drivers/gpu/drm/xe/xe_tlb_inval_types.h

+1 −0
Original line number Diff line number Diff line
@@ -80,6 +80,7 @@ struct xe_tlb_inval { 
	const struct xe_tlb_inval_ops *ops;

	/** @tlb_inval.seqno: TLB invalidation seqno, protected by CT lock */

#define TLB_INVALIDATION_SEQNO_MAX	0x100000

#define TLB_INVALIDATION_SEQNO_INVALID	TLB_INVALIDATION_SEQNO_MAX

	int seqno;

	/** @tlb_invalidation.seqno_lock: protects @tlb_invalidation.seqno */

	struct mutex seqno_lock;