linux-kernel - [PATCH 16/17] lib: Use mempcy_to/from

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Date:   Mon, 23 Nov 2020 22:07:54 -0800
From:   ira.weiny@...el.com
To:     Andrew Morton <akpm@...ux-foundation.org>
Cc:     Ira Weiny <ira.weiny@...el.com>,
        Alexei Starovoitov <ast@...nel.org>,
        Daniel Borkmann <daniel@...earbox.net>,
        Jérôme Glisse <jglisse@...hat.com>,
        Thomas Gleixner <tglx@...utronix.de>,
        Dave Hansen <dave.hansen@...el.com>,
        Matthew Wilcox <willy@...radead.org>,
        Christoph Hellwig <hch@...radead.org>,
        Dan Williams <dan.j.williams@...el.com>,
        Al Viro <viro@...iv.linux.org.uk>,
        Eric Biggers <ebiggers@...nel.org>,
        Luis Chamberlain <mcgrof@...nel.org>,
        Patrik Jakobsson <patrik.r.jakobsson@...il.com>,
        Jani Nikula <jani.nikula@...ux.intel.com>,
        Joonas Lahtinen <joonas.lahtinen@...ux.intel.com>,
        Rodrigo Vivi <rodrigo.vivi@...el.com>,
        David Howells <dhowells@...hat.com>, Chris Mason <clm@...com>,
        Josef Bacik <josef@...icpanda.com>,
        David Sterba <dsterba@...e.com>,
        Steve French <sfrench@...ba.org>,
        Jaegeuk Kim <jaegeuk@...nel.org>, Chao Yu <yuchao0@...wei.com>,
        Nicolas Pitre <nico@...xnic.net>,
        "Martin K. Petersen" <martin.petersen@...cle.com>,
        Brian King <brking@...ibm.com>,
        Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        Kirti Wankhede <kwankhede@...dia.com>,
        linux-kernel@...r.kernel.org, linux-fsdevel@...r.kernel.org
Subject: [PATCH 16/17] lib: Use mempcy_to/from_page()

From: Ira Weiny <ira.weiny@...el.com>

Remove kmap/mem*()/kunmap pattern and use memcpy_to/from_page()

Cc: Alexei Starovoitov <ast@...nel.org>
Cc: Daniel Borkmann <daniel@...earbox.net>
Cc: "Jérôme Glisse" <jglisse@...hat.com>
Signed-off-by: Ira Weiny <ira.weiny@...el.com>
---
 lib/test_bpf.c | 11 ++---------
 lib/test_hmm.c | 10 ++--------
 2 files changed, 4 insertions(+), 17 deletions(-)

diff --git a/lib/test_bpf.c b/lib/test_bpf.c
index ca7d635bccd9..def048bc1c48 100644
--- a/lib/test_bpf.c
+++ b/lib/test_bpf.c
@@ -14,6 +14,7 @@
 #include <linux/skbuff.h>
 #include <linux/netdevice.h>
 #include <linux/if_vlan.h>
+#include <linux/pagemap.h>
 #include <linux/random.h>
 #include <linux/highmem.h>
 #include <linux/sched.h>
@@ -6499,25 +6500,17 @@ static void *generate_test_data(struct bpf_test *test, int sub)
 		 * single fragment to the skb, filled with
 		 * test->frag_data.
 		 */
-		void *ptr;
-
 		page = alloc_page(GFP_KERNEL);
 
 		if (!page)
 			goto err_kfree_skb;
 
-		ptr = kmap(page);
-		if (!ptr)
-			goto err_free_page;
-		memcpy(ptr, test->frag_data, MAX_DATA);
-		kunmap(page);
+		memcpy_to_page(page, 0, test->frag_data, MAX_DATA);
 		skb_add_rx_frag(skb, 0, page, 0, MAX_DATA, MAX_DATA);
 	}
 
 	return skb;
 
-err_free_page:
-	__free_page(page);
 err_kfree_skb:
 	kfree_skb(skb);
 	return NULL;
diff --git a/lib/test_hmm.c b/lib/test_hmm.c
index 80a78877bd93..6a5fe7c4088b 100644
--- a/lib/test_hmm.c
+++ b/lib/test_hmm.c
@@ -321,16 +321,13 @@ static int dmirror_do_read(struct dmirror *dmirror, unsigned long start,
 	for (pfn = start >> PAGE_SHIFT; pfn < (end >> PAGE_SHIFT); pfn++) {
 		void *entry;
 		struct page *page;
-		void *tmp;
 
 		entry = xa_load(&dmirror->pt, pfn);
 		page = xa_untag_pointer(entry);
 		if (!page)
 			return -ENOENT;
 
-		tmp = kmap(page);
-		memcpy(ptr, tmp, PAGE_SIZE);
-		kunmap(page);
+		memcpy_from_page(ptr, page, 0, PAGE_SIZE);
 
 		ptr += PAGE_SIZE;
 		bounce->cpages++;
@@ -390,16 +387,13 @@ static int dmirror_do_write(struct dmirror *dmirror, unsigned long start,
 	for (pfn = start >> PAGE_SHIFT; pfn < (end >> PAGE_SHIFT); pfn++) {
 		void *entry;
 		struct page *page;
-		void *tmp;
 
 		entry = xa_load(&dmirror->pt, pfn);
 		page = xa_untag_pointer(entry);
 		if (!page || xa_pointer_tag(entry) != DPT_XA_TAG_WRITE)
 			return -ENOENT;
 
-		tmp = kmap(page);
-		memcpy(tmp, ptr, PAGE_SIZE);
-		kunmap(page);
+		memcpy_to_page(page, 0, ptr, PAGE_SIZE);
 
 		ptr += PAGE_SIZE;
 		bounce->cpages++;
-- 
2.28.0.rc0.12.gb6a658bd00c9