From: Nicolas Saenz Julienne Date: Tue, 20 Nov 2018 14:53:47 +0000 (+0100) Subject: staging: vchiq_util: get rid of unneeded memory barriers X-Git-Tag: v5.0-rc1~97^2~190 X-Git-Url: https://asedeno.scripts.mit.edu/gitweb/?a=commitdiff_plain;h=96f33712725e93677b2a91b68d93548068fb5c98;p=linux.git staging: vchiq_util: get rid of unneeded memory barriers All the memory operations featured in this file modify/access memory that is only accessed by the CPU. So we can assume that all the memory barrier handling done by the completion routines is good enough for us. Signed-off-by: Nicolas Saenz Julienne Acked-by: Stefan Wahren Signed-off-by: Greg Kroah-Hartman --- diff --git a/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_util.c b/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_util.c index 44b954daa74a..4b8554bc647e 100644 --- a/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_util.c +++ b/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_util.c @@ -84,20 +84,7 @@ void vchiu_queue_push(VCHIU_QUEUE_T *queue, VCHIQ_HEADER_T *header) flush_signals(current); } - /* - * Write to queue->storage must be visible after read from - * queue->read - */ - smp_mb(); - queue->storage[queue->write & (queue->size - 1)] = header; - - /* - * Write to queue->storage must be visible before write to - * queue->write - */ - smp_wmb(); - queue->write++; complete(&queue->push); @@ -112,12 +99,6 @@ VCHIQ_HEADER_T *vchiu_queue_peek(VCHIU_QUEUE_T *queue) complete(&queue->push); // We haven't removed anything from the queue. - /* - * Read from queue->storage must be visible after read from - * queue->write - */ - smp_rmb(); - return queue->storage[queue->read & (queue->size - 1)]; } @@ -130,20 +111,7 @@ VCHIQ_HEADER_T *vchiu_queue_pop(VCHIU_QUEUE_T *queue) flush_signals(current); } - /* - * Read from queue->storage must be visible after read from - * queue->write - */ - smp_rmb(); - header = queue->storage[queue->read & (queue->size - 1)]; - - /* - * Read from queue->storage must be visible before write to - * queue->read - */ - smp_mb(); - queue->read++; complete(&queue->pop);