[src/trunk]: src/sys/opencrypto update locking notes of opencrypto(9)

[knakahara <knakahara%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/090919986b7e
branches:  trunk
changeset: 355336:090919986b7e
user:      knakahara <knakahara%NetBSD.org@localhost>
date:      Wed Jul 26 06:44:50 2017 +0000

description:
update locking notes of opencrypto(9)

diffstat:

 sys/opencrypto/cryptodev.h |  15 ++++++++++-----
 1 files changed, 10 insertions(+), 5 deletions(-)

diffs (31 lines):

diff -r 4bffc789a474 -r 090919986b7e sys/opencrypto/cryptodev.h
--- a/sys/opencrypto/cryptodev.h        Wed Jul 26 06:44:01 2017 +0000
+++ b/sys/opencrypto/cryptodev.h        Wed Jul 26 06:44:50 2017 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: cryptodev.h,v 1.38 2017/07/18 06:01:36 knakahara Exp $ */
+/*     $NetBSD: cryptodev.h,v 1.39 2017/07/26 06:44:50 knakahara Exp $ */
 /*     $FreeBSD: src/sys/opencrypto/cryptodev.h,v 1.2.2.6 2003/07/02 17:04:50 sam Exp $        */
 /*     $OpenBSD: cryptodev.h,v 1.33 2002/07/17 23:52:39 art Exp $      */
 
@@ -670,12 +670,17 @@
  * + crypto_drivers[i] and its all members are protected by
  *   crypto_drivers[i].cc_lock (a spin lock)
  *       spin lock as crypto_unblock() can be called in interrupt context
- * + crp_q and crp_kq are procted by crypto_q_mtx (an adaptive lock)
- * + crp_ret_q, crp_ret_kq and crypto_exit_flag are protected by
- *   crypto_ret_q_mtx (a spin lock)
+ * + percpu'ed crp_q and crp_kq are procted by splsoftnet.
+ * + crp_ret_q, crp_ret_kq and crypto_exit_flag that are members of
+ *   struct crypto_crp_ret_qs are protected by crypto_crp_ret_qs.crp_ret_q_mtx
+ *   (a spin lock)
  *       spin lock as crypto_done() can be called in interrupt context
+ *       NOTE:
+ *       It is not known whether crypto_done()(in interrupt context) is called
+ *       in the same CPU as crypto_dispatch() is called.
+ *       So, struct crypto_crp_ret_qs cannot be percpu(9).
  *
  * Locking order:
- *     - crypto_q_mtx => crypto_drv_mtx => crypto_drivers[i].cc_lock
+ *     - crypto_drv_mtx => crypto_drivers[i].cc_lock
  */
 #endif /* _CRYPTO_CRYPTO_H_ */