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From: Sameer Goel <sameer.goel@linaro.org>
To: xen-devel@lists.xenproject.org, julien.grall@arm.com,
	mjaggi@caviumnetworks.com
Cc: sstabellini@kernel.org, wei.liu2@citrix.com,
	george.dunlap@eu.citrix.com, Andrew.Cooper3@citrix.com,
	andre.przywara@linaro.org, jbeulich@suse.com,
	Sameer Goel <sameer.goel@linaro.org>,
	Ian.Jackson@citrix.com, nd@arm.com, shankerd@codeaurora.org
Subject: [RFC v4 1/8] Port WARN_ON_ONCE() from Linux
Date: Mon, 18 Dec 2017 20:16:56 -0700	[thread overview]
Message-ID: <20171219031703.23420-2-sameer.goel@linaro.org> (raw)
In-Reply-To: <20171219031703.23420-1-sameer.goel@linaro.org>

Port WARN_ON_ONCE macro from Linux.

Signed-off-by: Sameer Goel <sameer.goel@linaro.org>
---
 xen/include/xen/lib.h | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/xen/include/xen/lib.h b/xen/include/xen/lib.h
index ed00ae1379..83206c0848 100644
--- a/xen/include/xen/lib.h
+++ b/xen/include/xen/lib.h
@@ -11,6 +11,17 @@
 #define BUG_ON(p)  do { if (unlikely(p)) BUG();  } while (0)
 #define WARN_ON(p) do { if (unlikely(p)) WARN(); } while (0)
 
+#define WARN_ON_ONCE(p)	({                          \
+    static bool __section(".data.unlikely") __warned; \
+    int __ret_warn_once = !!(p);                    \
+                                                    \
+    if (unlikely(__ret_warn_once && !__warned)) {   \
+        __warned = true;                            \
+        WARN_ON(1);                                 \
+    }                                               \
+    unlikely(__ret_warn_once);                      \
+})
+
 #if __GNUC__ > 4 || (__GNUC__ == 4 && __GNUC_MINOR__ >= 6)
 /* Force a compilation error if condition is true */
 #define BUILD_BUG_ON(cond) ({ _Static_assert(!(cond), "!(" #cond ")"); })
-- 
2.14.1


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  reply	other threads:[~2017-12-19  3:17 UTC|newest]

Thread overview: 37+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-12-19  3:16 [RFC v4 0/8] SMMUv3 driver Sameer Goel
2017-12-19  3:16 ` Sameer Goel [this message]
2018-01-23 11:33   ` [RFC v4 1/8] Port WARN_ON_ONCE() from Linux Julien Grall
2018-01-23 16:13   ` Wei Liu
2018-01-26  1:45     ` Sameer Goel
2017-12-19  3:16 ` [RFC v4 2/8] xen/bitops: Rename LOG_2 to ilog2 Sameer Goel
2018-01-23 11:36   ` Julien Grall
2018-01-23 11:39   ` Roger Pau Monné
2018-01-23 11:44     ` Julien Grall
2018-01-23 12:10       ` Roger Pau Monné
2018-01-23 12:17         ` Julien Grall
2017-12-19  3:16 ` [RFC v4 3/8] xen/linux_compat: Add a Linux compat header Sameer Goel
2018-01-23 16:28   ` Wei Liu
2018-01-23 16:51   ` Roger Pau Monné
2018-02-09 17:54     ` Sameer Goel
2017-12-19  3:16 ` [RFC v4 4/8] passthrough/arm: Modify SMMU driver to use generic device definition Sameer Goel
2018-01-23 11:41   ` Julien Grall
2017-12-19  3:17 ` [RFC v4 5/8] Add verbatim copy of arm-smmu-v3.c from Linux Sameer Goel
2017-12-19  3:17 ` [RFC v4 6/8] xen/iommu: smmu-v3: Add Xen specific code to enable the ported driver Sameer Goel
2018-01-03  5:47   ` Manish Jaggi
2018-01-15 20:34     ` Julien Grall
2018-01-16 12:37       ` Manish Jaggi
2018-01-16 13:13         ` Julien Grall
2018-01-23 15:18   ` Julien Grall
2018-02-09 17:56     ` Sameer Goel
2018-02-09 18:11       ` Julien Grall
2017-12-19  3:17 ` [RFC v4 7/8] xen/smmu: Add a new config define for legacy SMMU Sameer Goel
2018-01-23 15:26   ` Julien Grall
2017-12-19  3:17 ` [RFC v4 8/8] drivers/passthrough/arm: Refactor code for arm smmu drivers Sameer Goel
2018-01-03  5:34   ` Manish Jaggi
2018-01-15 20:41     ` Julien Grall
2018-01-16 12:40       ` Manish Jaggi
2018-01-16 13:14         ` Julien Grall
2018-01-16 13:27           ` Manish Jaggi
2018-01-16 13:40             ` Julien Grall
2018-01-17  6:37               ` Manish Jaggi
2018-01-23 15:38   ` Julien Grall

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