block: remove rq_flush_dcache_pages

This function is trivial, and flush_dcache_page is always defined, so
just open code it in the 2.5 callers.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Link: https://lore.kernel.org/r/20211117061404.331732-3-hch@lst.deSigned-off-by: Jens Axboe <axboe@kernel.dk>

block/blk-core.c

@@ -1300,25 +1300,6 @@ void blk_steal_bios(struct bio_list *list, struct request *rq)
 }
 EXPORT_SYMBOL_GPL(blk_steal_bios);
 
-#if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE
-/**
- * rq_flush_dcache_pages - Helper function to flush all pages in a request
- * @rq: the request to be flushed
- *
- * Description:
- *     Flush all pages in @rq.
- */
-void rq_flush_dcache_pages(struct request *rq)
-{
-	struct req_iterator iter;
-	struct bio_vec bvec;
-
-	rq_for_each_segment(bvec, rq, iter)
-		flush_dcache_page(bvec.bv_page);
-}
-EXPORT_SYMBOL_GPL(rq_flush_dcache_pages);
-#endif
-
 /**
  * blk_lld_busy - Check if underlying low-level drivers of a device are busy
  * @q : the queue of the device being checked

drivers/mtd/mtd_blkdevs.c

@@ -46,6 +46,8 @@ static blk_status_t do_blktrans_request(struct mtd_blktrans_ops *tr,
 			       struct mtd_blktrans_dev *dev,
 			       struct request *req)
 {
+	struct req_iterator iter;
+	struct bio_vec bvec;
 	unsigned long block, nsect;
 	char *buf;
 
@@ -76,13 +78,17 @@ static blk_status_t do_blktrans_request(struct mtd_blktrans_ops *tr,
 			}
 		}
 		kunmap(bio_page(req->bio));
-		rq_flush_dcache_pages(req);
+
+		rq_for_each_segment(bvec, req, iter)
+			flush_dcache_page(bvec.bv_page);
 		return BLK_STS_OK;
 	case REQ_OP_WRITE:
 		if (!tr->writesect)
 			return BLK_STS_IOERR;
 
-		rq_flush_dcache_pages(req);
+		rq_for_each_segment(bvec, req, iter)
+			flush_dcache_page(bvec.bv_page);
+
 		buf = kmap(bio_page(req->bio)) + bio_offset(req->bio);
 		for (; nsect > 0; nsect--, block++, buf += tr->blksize) {
 			if (tr->writesect(dev, block, buf)) {

drivers/mtd/ubi/block.c

@@ -294,6 +294,8 @@ static void ubiblock_do_work(struct work_struct *work)
 	int ret;
 	struct ubiblock_pdu *pdu = container_of(work, struct ubiblock_pdu, work);
 	struct request *req = blk_mq_rq_from_pdu(pdu);
+	struct req_iterator iter;
+	struct bio_vec bvec;
 
 	blk_mq_start_request(req);
 
@@ -305,7 +307,9 @@ static void ubiblock_do_work(struct work_struct *work)
 	blk_rq_map_sg(req->q, req, pdu->usgl.sg);
 
 	ret = ubiblock_read(pdu);
-	rq_flush_dcache_pages(req);
+
+	rq_for_each_segment(bvec, req, iter)
+		flush_dcache_page(bvec.bv_page);
 
 	blk_mq_end_request(req, errno_to_blk_status(ret));
 }

include/linux/blk-mq.h

@@ -1132,14 +1132,4 @@ static inline bool blk_req_can_dispatch_to_zone(struct request *rq)
 }
 #endif /* CONFIG_BLK_DEV_ZONED */
 
-#ifndef ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE
-# error	"You should define ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE for your platform"
-#endif
-#if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE
-void rq_flush_dcache_pages(struct request *rq);
-#else
-static inline void rq_flush_dcache_pages(struct request *rq)
-{
-}
-#endif /* ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE */
 #endif /* BLK_MQ_H */