From:   Vakul Garg <vakul.garg@nxp.com>
To:     "linux-crypto@vger.kernel.org" <linux-crypto@vger.kernel.org>,
        "herbert@gondor.apana.org.au" <herbert@gondor.apana.org.au>
CC:     Horia Geanta <horia.geanta@nxp.com>,
        Aymen Sghaier <aymen.sghaier@nxp.com>,
        Vakul Garg <vakul.garg@nxp.com>
Subject: [PATCH 1/3] crypto: caam/jr - Remove spinlock for output job ring
Thread-Topic: [PATCH 1/3] crypto: caam/jr - Remove spinlock for output job
 ring
Thread-Index: AQHU2uRPul9h7cTAM0qkye+2AiaphQ==
Date:   Fri, 15 Mar 2019 04:05:22 +0000
Message-ID: <20190315040239.24705-2-vakul.garg@nxp.com>
References: <20190315040239.24705-1-vakul.garg@nxp.com>
In-Reply-To: <20190315040239.24705-1-vakul.garg@nxp.com>
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For each job ring pair, the output ring is processed exactly by one cpu
at a time under a tasklet context (one per ring). Therefore, there is no
need to protect a job ring's access & its private data structure using a
lock. Hence the lock can be removed.

Signed-off-by: Vakul Garg <vakul.garg@nxp.com>
---
 drivers/crypto/caam/intern.h | 1 -
 drivers/crypto/caam/jr.c     | 5 -----
 2 files changed, 6 deletions(-)

diff --git a/drivers/crypto/caam/intern.h b/drivers/crypto/caam/intern.h
index 30d5b6c5892f..48d62e020599 100644
--- a/drivers/crypto/caam/intern.h
+++ b/drivers/crypto/caam/intern.h
@@ -56,7 +56,6 @@ struct caam_drv_private_jr {
 	u32 inpring_avail;	/* Number of free entries in input ring */
 	int head;			/* entinfo (s/w ring) head index */
 	dma_addr_t *inpring;	/* Base of input ring, alloc DMA-safe */
-	spinlock_t outlock ____cacheline_aligned; /* Output ring index lock */
 	int out_ring_read_index;	/* Output index "tail" */
 	int tail;			/* entinfo (s/w ring) tail index */
 	struct jr_outentry *outring;	/* Base of output ring, DMA-safe */
diff --git a/drivers/crypto/caam/jr.c b/drivers/crypto/caam/jr.c
index b9caa95755d1..89de7297d099 100644
--- a/drivers/crypto/caam/jr.c
+++ b/drivers/crypto/caam/jr.c
@@ -177,8 +177,6 @@ static void caam_jr_dequeue(unsigned long devarg)
=20
 		head =3D READ_ONCE(jrp->head);
=20
-		spin_lock(&jrp->outlock);
-
 		sw_idx =3D tail =3D jrp->tail;
 		hw_idx =3D jrp->out_ring_read_index;
=20
@@ -234,8 +232,6 @@ static void caam_jr_dequeue(unsigned long devarg)
 			jrp->tail =3D tail;
 		}
=20
-		spin_unlock(&jrp->outlock);
-
 		/* Finally, execute user's callback */
 		usercall(dev, userdesc, userstatus, userarg);
 		outring_used--;
@@ -452,7 +448,6 @@ static int caam_jr_init(struct device *dev)
 	jrp->inpring_avail =3D JOBR_DEPTH;
=20
 	spin_lock_init(&jrp->inplock);
-	spin_lock_init(&jrp->outlock);
=20
 	/* Select interrupt coalescing parameters */
 	clrsetbits_32(&jrp->rregs->rconfig_lo, 0, JOBR_INTC |
--=20
2.13.6