linux-kernel - [PATCH] rdma/qib: Remove deprecated kmap() call

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Message-Id: <20230217-kmap-qib-v1-1-e5a6fde167e0@intel.com>
Date:   Tue, 07 Mar 2023 09:15:31 -0800
From:   Ira Weiny <ira.weiny@...el.com>
To:     Dennis Dalessandro <dennis.dalessandro@...nelisnetworks.com>,
        Jason Gunthorpe <jgg@...pe.ca>,
        Leon Romanovsky <leon@...nel.org>
Cc:     linux-rdma@...r.kernel.org, linux-kernel@...r.kernel.org,
        Ira Weiny <ira.weiny@...el.com>
Subject: [PATCH] rdma/qib: Remove deprecated kmap() call

kmap() has been deprecated in favor of the kmap_local_page() call.
kmap_local_page() is thread local.

In the sdma coalesce case the page allocated is potentially free'ed in a
different context through qib_sdma_get_complete() ->
qib_user_sdma_make_progress().  The use of kmap_local_page() is
inappropriate in this call path.  However, the page is allocated using
GFP_KERNEL and will never be from highmem.

Remove the use of kmap calls and use page_address() in this case.

Signed-off-by: Ira Weiny <ira.weiny@...el.com>
---
 drivers/infiniband/hw/qib/qib_user_sdma.c | 11 +++--------
 1 file changed, 3 insertions(+), 8 deletions(-)

diff --git a/drivers/infiniband/hw/qib/qib_user_sdma.c b/drivers/infiniband/hw/qib/qib_user_sdma.c
index 9fe03d6ffac1..336eb15a721f 100644
--- a/drivers/infiniband/hw/qib/qib_user_sdma.c
+++ b/drivers/infiniband/hw/qib/qib_user_sdma.c
@@ -320,7 +320,6 @@ static int qib_user_sdma_page_to_frags(const struct qib_devdata *dd,
 			unpin_user_page(page);
 		} else {
 			/* coalesce case */
-			kunmap(page);
 			__free_page(page);
 		}
 		ret = -ENOMEM;
@@ -572,7 +571,7 @@ static int qib_user_sdma_coalesce(const struct qib_devdata *dd,
 		goto done;
 	}
 
-	mpage = kmap(page);
+	mpage = page_address(page);
 	mpage_save = mpage;
 	for (i = 0; i < niov; i++) {
 		int cfur;
@@ -581,7 +580,7 @@ static int qib_user_sdma_coalesce(const struct qib_devdata *dd,
 				      iov[i].iov_base, iov[i].iov_len);
 		if (cfur) {
 			ret = -EFAULT;
-			goto free_unmap;
+			goto page_free;
 		}
 
 		mpage += iov[i].iov_len;
@@ -592,8 +591,7 @@ static int qib_user_sdma_coalesce(const struct qib_devdata *dd,
 			page, 0, 0, len, mpage_save);
 	goto done;
 
-free_unmap:
-	kunmap(page);
+page_free:
 	__free_page(page);
 done:
 	return ret;
@@ -627,9 +625,6 @@ static void qib_user_sdma_free_pkt_frag(struct device *dev,
 				       pkt->addr[i].dma_length,
 				       DMA_TO_DEVICE);
 
-		if (pkt->addr[i].kvaddr)
-			kunmap(pkt->addr[i].page);
-
 		if (pkt->addr[i].put_page)
 			unpin_user_page(pkt->addr[i].page);
 		else

---
base-commit: 8ca09d5fa3549d142c2080a72a4c70ce389163cd
change-id: 20230217-kmap-qib-27a563231f85

Best regards,
-- 
Ira Weiny <ira.weiny@...el.com>