Backports Archive on lore.kernel.org
 help / color / Atom feed
From: Hauke Mehrtens <hauke@hauke-m.de>
To: backports@vger.kernel.org
Cc: johannes@sipsolutions.net, Hauke Mehrtens <hauke@hauke-m.de>
Subject: [PATCH 5/8] backports: rcupdate.h: Add rcu_swap_protected()
Date: Sat, 21 Mar 2020 00:39:47 +0100
Message-ID: <20200320233950.32257-6-hauke@hauke-m.de> (raw)
In-Reply-To: <20200320233950.32257-1-hauke@hauke-m.de>

Backport rcu_swap_protected() from upstream Linux commit 26e3e3cb0560
("scsi: rcu: Introduce rcu_swap_protected()"). This is used by the mt76
driver.

Signed-off-by: Hauke Mehrtens <hauke@hauke-m.de>
---
 backport/backport-include/linux/rcupdate.h | 18 ++++++++++++++++++
 1 file changed, 18 insertions(+)

diff --git a/backport/backport-include/linux/rcupdate.h b/backport/backport-include/linux/rcupdate.h
index cec4b3e8..db501007 100644
--- a/backport/backport-include/linux/rcupdate.h
+++ b/backport/backport-include/linux/rcupdate.h
@@ -59,4 +59,22 @@ rcu_head_after_call_rcu(struct rcu_head *rhp, rcu_callback_t f)
 }
 #endif /* < 4.20 */
 
+#ifndef rcu_swap_protected
+/**
+ * rcu_swap_protected() - swap an RCU and a regular pointer
+ * @rcu_ptr: RCU pointer
+ * @ptr: regular pointer
+ * @c: the conditions under which the dereference will take place
+ *
+ * Perform swap(@rcu_ptr, @ptr) where @rcu_ptr is an RCU-annotated pointer and
+ * @c is the argument that is passed to the rcu_dereference_protected() call
+ * used to read that pointer.
+ */
+#define rcu_swap_protected(rcu_ptr, ptr, c) do {			\
+	typeof(ptr) __tmp = rcu_dereference_protected((rcu_ptr), (c));	\
+	rcu_assign_pointer((rcu_ptr), (ptr));				\
+	(ptr) = __tmp;							\
+} while (0)
+#endif
+
 #endif /* __BACKPORT_LINUX_RCUPDATE_H */
-- 
2.20.1

--
To unsubscribe from this list: send the line "unsubscribe backports" in

  parent reply index

Thread overview: 9+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-03-20 23:39 [PATCH 0/8] backports: Update to version 5.5.10 Hauke Mehrtens
2020-03-20 23:39 ` [PATCH 1/8] backports: patches: Refresh against kernel 5.5.10 Hauke Mehrtens
2020-03-20 23:39 ` [PATCH 2/8] backports: fs.h: Add compat_ptr_ioctl() Hauke Mehrtens
2020-03-20 23:39 ` [PATCH 3/8] backports: stddef.h: Add sizeof_field() Hauke Mehrtens
2020-03-20 23:39 ` [PATCH 4/8] backports: Make qtnfmac depend on kernel 5.1 or later Hauke Mehrtens
2020-03-20 23:39 ` Hauke Mehrtens [this message]
2020-03-20 23:39 ` [PATCH 6/8] backports: netdevice.h: Add return value to napi_complete() Hauke Mehrtens
2020-03-20 23:39 ` [PATCH 7/8] backports: Do not build BPAUTO_BUILD_SYSTEM_DATA_VERIFICATION on < 3.13 Hauke Mehrtens
2020-03-20 23:39 ` [PATCH 8/8] backports: page_ref.h: Exclude page_ref_count() on kernel >= 4.4.216 Hauke Mehrtens

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20200320233950.32257-6-hauke@hauke-m.de \
    --to=hauke@hauke-m.de \
    --cc=backports@vger.kernel.org \
    --cc=johannes@sipsolutions.net \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

Backports Archive on lore.kernel.org

Archives are clonable:
	git clone --mirror https://lore.kernel.org/backports/0 backports/git/0.git

	# If you have public-inbox 1.1+ installed, you may
	# initialize and index your mirror using the following commands:
	public-inbox-init -V2 backports backports/ https://lore.kernel.org/backports \
		backports@vger.kernel.org
	public-inbox-index backports

Example config snippet for mirrors

Newsgroup available over NNTP:
	nntp://nntp.lore.kernel.org/org.kernel.vger.backports


AGPL code for this site: git clone https://public-inbox.org/public-inbox.git