[src/trunk]: src/sys/external/bsd/drm2/include/linux Kludge up <linux/ratelim...

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

details:   https://anonhg.NetBSD.org/src/rev/578fabf4d10f
branches:  trunk
changeset: 1027862:578fabf4d10f
user:      riastradh <riastradh%NetBSD.org@localhost>
date:      Sun Dec 19 00:59:17 2021 +0000

description:
Kludge up <linux/ratelimit.h> with ppsratecheck.

diffstat:

 sys/external/bsd/drm2/include/linux/ratelimit.h |  44 ++++++++++++++++++++++++-
 1 files changed, 43 insertions(+), 1 deletions(-)

diffs (56 lines):

diff -r 84fd81c9fb6f -r 578fabf4d10f sys/external/bsd/drm2/include/linux/ratelimit.h
--- a/sys/external/bsd/drm2/include/linux/ratelimit.h   Sun Dec 19 00:59:10 2021 +0000
+++ b/sys/external/bsd/drm2/include/linux/ratelimit.h   Sun Dec 19 00:59:17 2021 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: ratelimit.h,v 1.2 2014/03/18 18:20:43 riastradh Exp $  */
+/*     $NetBSD: ratelimit.h,v 1.3 2021/12/19 00:59:17 riastradh Exp $  */
 
 /*-
  * Copyright (c) 2013 The NetBSD Foundation, Inc.
@@ -32,4 +32,46 @@
 #ifndef _LINUX_RATELIMIT_H_
 #define _LINUX_RATELIMIT_H_
 
+#include <sys/atomic.h>
+#include <sys/stdbool.h>
+#include <sys/time.h>
+
+struct linux_ratelimit {
+       volatile unsigned       rl_lock;
+       struct timeval          rl_lasttime;
+       int                     rl_curpps;
+       unsigned                rl_maxpps;
+};
+
+/*
+ * XXX Assumes hz=100 so this works in static initializers, and/or
+ * hopes the caller just uses DEFAULT_RATELIMIT_INTERVAL and doesn't
+ * mention hz.
+ */
+#define        DEFAULT_RATELIMIT_INTERVAL      (5*100)
+#define        DEFAULT_RATELIMIT_BURST         10
+
+#define        DEFINE_RATELIMIT_STATE(n, i, b)                                       \
+       struct linux_ratelimit n = {                                          \
+               .rl_lock = 0,                                                 \
+               .rl_lasttime = { .tv_sec = 0, .tv_usec = 0 },                 \
+               .rl_curpps = 0,                                               \
+               .rl_maxpps = (b)/((i)/100),                                   \
+       }
+
+static inline bool
+__ratelimit(struct linux_ratelimit *r)
+{
+       int ok;
+
+       if (atomic_cas_uint(&r->rl_lock, 0, 1))
+               return false;
+       membar_enter();
+       ok = ppsratecheck(&r->rl_lasttime, &r->rl_curpps, r->rl_maxpps);
+       membar_exit();
+       r->rl_lock = 0;
+
+       return ok;
+}
+
 #endif  /* _LINUX_RATELIMIT_H_ */