Subject: [PATCH RFC PKS/PMEM 53/58] lib: Utilize new kmap_thread()

From: [email-masked]
Date: Fri, 9 Oct 2020 12:50:28 -0700

From: Ira Weiny <[email-masked]>

These kmap() calls are localized to a single thread.  To avoid the over
head of global PKRS updates use the new kmap_thread() call.

Cc: Alexander Viro <[email-masked]>
Cc: "Jérôme Glisse" <[email-masked]>
Cc: Martin KaFai Lau <[email-masked]>
Cc: Song Liu <[email-masked]>
Cc: Yonghong Song <[email-masked]>
Cc: Andrii Nakryiko <[email-masked]>
Cc: John Fastabend <[email-masked]>
Cc: KP Singh <[email-masked]>
Signed-off-by: Ira Weiny <[email-masked]>
---
 lib/iov_iter.c | 12 ++++++------
 lib/test_bpf.c |  4 ++--
 lib/test_hmm.c |  8 ++++----
 3 files changed, 12 insertions(+), 12 deletions(-)

diff --git a/lib/iov_iter.c b/lib/iov_iter.c
index 5e40786c8f12..1d47f957cf95 100644
--- a/lib/iov_iter.c
+++ b/lib/iov_iter.c
@@ -208,7 +208,7 @@ static size_t copy_page_to_iter_iovec(struct page *page, size_t offset, size_t b
 	}
 	/* Too bad - revert to non-atomic kmap */
 
-	kaddr = kmap(page);
+	kaddr = kmap_thread(page);
 	from = kaddr + offset;
 	left = copyout(buf, from, copy);
 	copy -= left;
@@ -225,7 +225,7 @@ static size_t copy_page_to_iter_iovec(struct page *page, size_t offset, size_t b
 		from += copy;
 		bytes -= copy;
 	}
-	kunmap(page);
+	kunmap_thread(page);
 
 done:
 	if (skip == iov->iov_len) {
@@ -292,7 +292,7 @@ static size_t copy_page_from_iter_iovec(struct page *page, size_t offset, size_t
 	}
 	/* Too bad - revert to non-atomic kmap */
 
-	kaddr = kmap(page);
+	kaddr = kmap_thread(page);
 	to = kaddr + offset;
 	left = copyin(to, buf, copy);
 	copy -= left;
@@ -309,7 +309,7 @@ static size_t copy_page_from_iter_iovec(struct page *page, size_t offset, size_t
 		to += copy;
 		bytes -= copy;
 	}
-	kunmap(page);
+	kunmap_thread(page);
 
 done:
 	if (skip == iov->iov_len) {
@@ -1742,10 +1742,10 @@ int iov_iter_for_each_range(struct iov_iter *i, size_t bytes,
 		return 0;
 
 	iterate_all_kinds(i, bytes, v, -EINVAL, ({
-		w.iov_base = kmap(v.bv_page) + v.bv_offset;
+		w.iov_base = kmap_thread(v.bv_page) + v.bv_offset;
 		w.iov_len = v.bv_len;
 		err = f(&w, context);
-		kunmap(v.bv_page);
+		kunmap_thread(v.bv_page);
 		err;}), ({
 		w = v;
 		err = f(&w, context);})
diff --git a/lib/test_bpf.c b/lib/test_bpf.c
index ca7d635bccd9..441f822f56ba 100644
--- a/lib/test_bpf.c
+++ b/lib/test_bpf.c
@@ -6506,11 +6506,11 @@ static void *generate_test_data(struct bpf_test *test, int sub)
 		if (!page)
 			goto err_kfree_skb;
 
-		ptr = kmap(page);
+		ptr = kmap_thread(page);
 		if (!ptr)
 			goto err_free_page;
 		memcpy(ptr, test->frag_data, MAX_DATA);
-		kunmap(page);
+		kunmap_thread(page);
 		skb_add_rx_frag(skb, 0, page, 0, MAX_DATA, MAX_DATA);
 	}
 
diff --git a/lib/test_hmm.c b/lib/test_hmm.c
index e7dc3de355b7..e40d26f97f45 100644
--- a/lib/test_hmm.c
+++ b/lib/test_hmm.c
@@ -329,9 +329,9 @@ static int dmirror_do_read(struct dmirror *dmirror, unsigned long start,
 		if (!page)
 			return -ENOENT;
 
-		tmp = kmap(page);
+		tmp = kmap_thread(page);
 		memcpy(ptr, tmp, PAGE_SIZE);
-		kunmap(page);
+		kunmap_thread(page);
 
 		ptr += PAGE_SIZE;
 		bounce->cpages++;
@@ -398,9 +398,9 @@ static int dmirror_do_write(struct dmirror *dmirror, unsigned long start,
 		if (!page || xa_pointer_tag(entry) != DPT_XA_TAG_WRITE)
 			return -ENOENT;
 
-		tmp = kmap(page);
+		tmp = kmap_thread(page);
 		memcpy(tmp, ptr, PAGE_SIZE);
-		kunmap(page);
+		kunmap_thread(page);
 
 		ptr += PAGE_SIZE;
 		bounce->cpages++;
-- 
2.28.0.rc0.12.gb6a658bd00c9