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Commit cf41f3e0 authored by Yong Ding's avatar Yong Ding
Browse files

soc: qcom: hab: refine hab virtual channel's resource free 



Whenever a vchan is locally closed in hab_vchan_close or hab_free,
4 actions should be taken immediately, including,
 - remove it from the local hab context
 - mark its local closed flag
 - notify remote side and unblock local blocking calls over it
 - decrease the refcnt on the vchan

Change-Id: I3fbde9464f6405b6dadac248768a5fd857a29128
Signed-off-by: default avatarYong Ding <yongding@codeaurora.org>
parent 67b38b04

drivers/soc/qcom/hab/hab.c

+13 −20
Original line number Diff line number Diff line
@@ -720,11 +720,18 @@ void hab_vchan_close(struct uhab_context *ctx, int32_t vcid) 
	write_lock(&ctx->ctx_lock);

	list_for_each_entry_safe(vchan, tmp, &ctx->vchannels, node) {

		if (vchan->id == vcid) {

			/* local close starts */

			vchan->closed = 1;

			write_unlock(&ctx->ctx_lock);



			/* vchan is not in this ctx anymore */

			list_del(&vchan->node);

			ctx->vcnt--;



			pr_debug("vcid %x remote %x session %d refcnt %d\n",

				vchan->id, vchan->otherend_id,

				vchan->session_id, get_refcnt(vchan->refcount));



			write_unlock(&ctx->ctx_lock);

			/* unblocking blocked in-calls */

			hab_vchan_stop_notify(vchan);

			hab_vchan_put(vchan); /* there is a lock inside */
@@ -1069,28 +1076,14 @@ static int hab_release(struct inode *inodep, struct file *filep) 
	write_lock(&ctx->ctx_lock);

	/* notify remote side on vchan closing */

	list_for_each_entry_safe(vchan, tmp, &ctx->vchannels, node) {

		/* local close starts */

		vchan->closed = 1;



		list_del(&vchan->node); /* vchan is not in this ctx anymore */

		ctx->vcnt--;



		if (!vchan->closed) { /* locally hasn't closed yet */

			if (!kref_get_unless_zero(&vchan->refcount)) {

				pr_err("vchan %x %x refcnt %d mismanaged closed %d remote closed %d\n",

					vchan->id,

					vchan->otherend_id,

					get_refcnt(vchan->refcount),

					vchan->closed, vchan->otherend_closed);

				continue; /* vchan is already being freed */

			} else {

		write_unlock(&ctx->ctx_lock);

		hab_vchan_stop_notify(vchan);

				/* put for notify. shouldn't cause free */

				hab_vchan_put(vchan);

				write_lock(&ctx->ctx_lock);

			}

		} else

			continue;



		/* for the missing local vchan close */

		write_unlock(&ctx->ctx_lock);

		hab_vchan_put(vchan); /* there is a lock inside */

		write_lock(&ctx->ctx_lock);

	}

drivers/soc/qcom/hab/hab_vchan.c

+4 −36
Original line number Diff line number Diff line
@@ -85,9 +85,6 @@ hab_vchan_free(struct kref *ref) 
	}

	spin_unlock_bh(&vchan->rx_lock);



	/* the release vchan from ctx was done earlier in vchan close() */

	hab_ctx_put(ctx); /* now ctx is not needed from this vchan's view */



	/* release vchan from pchan. no more msg for this vchan */

	write_lock_bh(&pchan->vchans_lock);

	list_for_each_entry_safe(vc, vc_tmp, &pchan->vchannels, pnode) {
@@ -100,6 +97,9 @@ hab_vchan_free(struct kref *ref) 
	}

	write_unlock_bh(&pchan->vchans_lock);



	/* the release vchan from ctx was done earlier in vchan close() */

	hab_ctx_put(ctx); /* now ctx is not needed from this vchan's view */



	/* release idr at the last so same idr will not be used early */

	spin_lock_bh(&pchan->vid_lock);

	idr_remove(&pchan->vchan_idr, HAB_VCID_GET_ID(vchan->id));
@@ -274,42 +274,10 @@ int hab_vchan_find_domid(struct virtual_channel *vchan) 
	return vchan ? vchan->pchan->dom_id : -1;

}



/* this sould be only called once after refcnt is zero */

static void hab_vchan_schedule_free(struct kref *ref)

{

	struct virtual_channel *vchanin =

		container_of(ref, struct virtual_channel, refcount);

	struct uhab_context *ctx = vchanin->ctx;

	struct virtual_channel *vchan, *tmp;

	int bnotify = 0;



	/*

	 * similar logic is in ctx free. if ctx free runs first,

	 * this is skipped

	 */

	write_lock_bh(&ctx->ctx_lock);

	list_for_each_entry_safe(vchan, tmp, &ctx->vchannels, node) {

		if (vchan == vchanin) {

			pr_debug("vchan free refcnt = %d\n",

					 get_refcnt(vchan->refcount));

			ctx->vcnt--;

			list_del(&vchan->node);

			bnotify = 1;

			break;

		}

	}

	write_unlock_bh(&ctx->ctx_lock);



	if (bnotify)

		hab_vchan_stop_notify(vchan);



	hab_vchan_free(ref);

}



void hab_vchan_put(struct virtual_channel *vchan)

{

	if (vchan)

		kref_put(&vchan->refcount, hab_vchan_schedule_free);

		kref_put(&vchan->refcount, hab_vchan_free);

}



int hab_vchan_query(struct uhab_context *ctx, int32_t vcid, uint64_t *ids,