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From:   David Laight <David.Laight@ACULAB.COM>
To:     "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
        "'Andy Shevchenko'" <andriy.shevchenko@linux.intel.com>,
        'Andrew Morton' <akpm@linux-foundation.org>,
        "Matthew Wilcox (Oracle)" <willy@infradead.org>,
        Christoph Hellwig <hch@infradead.org>,
        "Jason A. Donenfeld" <Jason@zx2c4.com>
Subject: [PATCH next 1/5] minmax: Add min_unsigned(a, b) and max_unsigned(a,
 b)
Thread-Topic: [PATCH next 1/5] minmax: Add min_unsigned(a, b) and
 max_unsigned(a, b)
Thread-Index: Adm+2zJY+ejT7PjHQ52rHHfvsNPoKA==
Date:   Tue, 25 Jul 2023 10:00:45 +0000
Message-ID: <eb4a78e460d040058f7f6299c083e25a@AcuMS.aculab.com>
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These can be used when min()/max() errors a signed v unsigned
compare when the signed value is known to be non-negative.

Unlike min_t(some_unsigned_type, a, b) min_unsigned() will never
mask off high bits if an inappropriate type is selected.

Signed-off-by: David Laight <david.laight@aculab.com>
---
 include/linux/minmax.h | 17 +++++++++++++++++
 1 file changed, 17 insertions(+)

diff --git a/include/linux/minmax.h b/include/linux/minmax.h
index 396df1121bff..531860e9cc55 100644
--- a/include/linux/minmax.h
+++ b/include/linux/minmax.h
@@ -73,6 +73,23 @@
  */
 #define max(x, y)	__careful_cmp(x, y, >)
 
+/**
+ * min_unsigned - return minimum of two non-negative values
+ *   Signed types are zero extended to match a larger unsigned type.
+ * @x: first value
+ * @y: second value
+ */
+#define min_unsigned(x, y)	\
+	__careful_cmp((x) + 0u + 0ul + 0ull, (y) + 0u + 0ul + 0ull, <)
+
+/**
+ * max_unsigned - return maximum of two non-negative values
+ * @x: first value
+ * @y: second value
+ */
+#define max_unsigned(x, y)	\
+	__careful_cmp((x) + 0u + 0ul + 0ull, (y) + 0u + 0ul + 0ull, >)
+
 /**
  * min3 - return minimum of three values
  * @x: first value
-- 
2.17.1

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