Patch "minmax: Introduce {min,max}_array()" has been added to the 6.1-stable tree

[gregkh at linuxfoundation.org]

This is a note to let you know that I've just added the patch titled

    minmax: Introduce {min,max}_array()

to the 6.1-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     minmax-introduce-min-max-_array.patch
and it can be found in the queue-6.1 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable at vger.kernel.org> know about it.


>From prvs=3555e8f33=farbere at amazon.com Wed Sep 24 22:25:22 2025
From: Eliav Farber <farbere at amazon.com>
Date: Wed, 24 Sep 2025 20:23:03 +0000
Subject: minmax: Introduce {min,max}_array()
To: <linux at armlinux.org.uk>, <richard at nod.at>, <anton.ivanov at cambridgegreys.com>, <johannes at sipsolutions.net>, <dave.hansen at linux.intel.com>, <luto at kernel.org>, <peterz at infradead.org>, <tglx at linutronix.de>, <mingo at redhat.com>, <bp at alien8.de>, <x86 at kernel.org>, <hpa at zytor.com>, <tony.luck at intel.com>, <qiuxu.zhuo at intel.com>, <mchehab at kernel.org>, <james.morse at arm.com>, <rric at kernel.org>, <harry.wentland at amd.com>, <sunpeng.li at amd.com>, <Rodrigo.Siqueira at amd.com>, <alexander.deucher at amd.com>, <christian.koenig at amd.com>, <Xinhui.Pan at amd.com>, <airlied at gmail.com>, <daniel at ffwll.ch>, <evan.quan at amd.com>, <james.qian.wang at arm.com>, <liviu.dudau at arm.com>, <mihail.atanassov at arm.com>, <brian.starkey at arm.com>, <maarten.lankhorst at linux.intel.com>, <mripard at kernel.org>, <tzimmermann at suse.de>, <robdclark at gmail.com>, <quic_abhinavk at quicinc.com>, <dmitry.baryshkov at linaro.org>, <sean at poorly.run>, <jdelvare at suse.com>, <linux at roeck-us.net>, <linus.walleij at linaro.org>, <dmitry.torokhov at gmail.com>, <maz at k
 ernel.org>, <wens at csie.org>, <jernej.skrabec at gmail.com>, <samuel at sholland.org>, <agk at redhat.com>, <snitzer at kernel.org>, <dm-devel at redhat.com>, <rajur at chelsio.com>, <davem at davemloft.net>, <edumazet at google.com>, <kuba at kernel.org>, <pabeni at redhat.com>, <peppe.cavallaro at st.com>, <alexandre.torgue at foss.st.com>, <joabreu at synopsys.com>, <mcoquelin.stm32 at gmail.com>, <krzysztof.kozlowski at linaro.org>, <malattia at linux.it>, <hdegoede at redhat.com>, <markgross at kernel.org>, <artur.paszkiewicz at intel.com>, <jejb at linux.ibm.com>, <martin.petersen at oracle.com>, <sakari.ailus at linux.intel.com>, <gregkh at linuxfoundation.org>, <fei1.li at intel.com>, <clm at fb.com>, <josef at toxicpanda.com>, <dsterba at suse.com>, <jack at suse.com>, <tytso at mit.edu>, <adilger.kernel at dilger.ca>, <dushistov at mail.ru>, <luc.vanoostenryck at gmail.com>, <rostedt at goodmis.org>, <mhiramat at kernel.org>, <pmladek at suse.com>, <senozhatsky at chromium.org>, <andriy.shevchenko at linux.intel.com>, <linux at rasmusvillemoes.dk>, <minchan at kernel.org>, <ngupta at vflare.
 org>, <akpm at linux-foundation.org>, <yoshfuji at linux-ipv6.org>, <dsahern at kernel.org>, <pablo at netfilter.org>, <kadlec at netfilter.org>, <fw at strlen.de>, <jmaloy at redhat.com>, <ying.xue at windriver.com>, <andrii at kernel.org>, <mykolal at fb.com>, <ast at kernel.org>, <daniel at iogearbox.net>, <martin.lau at linux.dev>, <song at kernel.org>, <yhs at fb.com>, <john.fastabend at gmail.com>, <kpsingh at kernel.org>, <sdf at google.com>, <haoluo at google.com>, <jolsa at kernel.org>, <shuah at kernel.org>, <keescook at chromium.org>, <wad at chromium.org>, <willy at infradead.org>, <farbere at amazon.com>, <sashal at kernel.org>, <ruanjinjie at huawei.com>, <quic_akhilpo at quicinc.com>, <David.Laight at ACULAB.COM>, <herve.codina at bootlin.com>, <linux-arm-kernel at lists.infradead.org>, <linux-kernel at vger.kernel.org>, <linux-um at lists.infradead.org>, <linux-edac at vger.kernel.org>, <amd-gfx at lists.freedesktop.org>, <dri-devel at lists.freedesktop.org>, <linux-arm-msm at vger.kernel.org>, <freedreno at lists.freedesktop.org>, <linux-hwmon at vger.kernel.org>, <linux-input at vge
 r.kernel.org>, <linux-sunxi at lists.linux.dev>, <linux-media at vger.kernel.org>, <netdev at vger.kernel.org>, <linux-stm32 at st-md-mailman.stormreply.com>, <platform-driver-x86 at vger.kernel.org>, <linux-scsi at vger.kernel.org>, <linux-staging at lists.linux.dev>, <linux-btrfs at vger.kernel.org>, <linux-ext4 at vger.kernel.org>, <linux-sparse at vger.kernel.org>, <linux-mm at kvack.org>, <netfilter-devel at vger.kernel.org>, <coreteam at netfilter.org>, <tipc-discussion at lists.sourceforge.net>, <bpf at vger.kernel.org>, <linux-kselftest at vger.kernel.org>, <stable at vger.kernel.org>
Cc: Andy Shevchenko <andy.shevchenko at gmail.com>, Christophe Leroy <christophe.leroy at csgroup.eu>
Message-ID: <20250924202320.32333-3-farbere at amazon.com>

From: Herve Codina <herve.codina at bootlin.com>

[ Upstream commit c952c748c7a983a8bda9112984e6f2c1f6e441a5 ]

Introduce min_array() (resp max_array()) in order to get the
minimal (resp maximum) of values present in an array.

Signed-off-by: Herve Codina <herve.codina at bootlin.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko at gmail.com>
Reviewed-by: Christophe Leroy <christophe.leroy at csgroup.eu>
Link: https://lore.kernel.org/r/20230623085830.749991-8-herve.codina@bootlin.com
Signed-off-by: Mark Brown <broonie at kernel.org>
Signed-off-by: Eliav Farber <farbere at amazon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh at linuxfoundation.org>
---
 include/linux/minmax.h |   64 +++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 64 insertions(+)

--- a/include/linux/minmax.h
+++ b/include/linux/minmax.h
@@ -168,6 +168,70 @@
  */
 #define max_t(type, x, y)	__careful_cmp(max, (type)(x), (type)(y))
 
+/*
+ * Remove a const qualifier from integer types
+ * _Generic(foo, type-name: association, ..., default: association) performs a
+ * comparison against the foo type (not the qualified type).
+ * Do not use the const keyword in the type-name as it will not match the
+ * unqualified type of foo.
+ */
+#define __unconst_integer_type_cases(type)	\
+	unsigned type:  (unsigned type)0,	\
+	signed type:    (signed type)0
+
+#define __unconst_integer_typeof(x) typeof(			\
+	_Generic((x),						\
+		char: (char)0,					\
+		__unconst_integer_type_cases(char),		\
+		__unconst_integer_type_cases(short),		\
+		__unconst_integer_type_cases(int),		\
+		__unconst_integer_type_cases(long),		\
+		__unconst_integer_type_cases(long long),	\
+		default: (x)))
+
+/*
+ * Do not check the array parameter using __must_be_array().
+ * In the following legit use-case where the "array" passed is a simple pointer,
+ * __must_be_array() will return a failure.
+ * --- 8< ---
+ * int *buff
+ * ...
+ * min = min_array(buff, nb_items);
+ * --- 8< ---
+ *
+ * The first typeof(&(array)[0]) is needed in order to support arrays of both
+ * 'int *buff' and 'int buff[N]' types.
+ *
+ * The array can be an array of const items.
+ * typeof() keeps the const qualifier. Use __unconst_integer_typeof() in order
+ * to discard the const qualifier for the __element variable.
+ */
+#define __minmax_array(op, array, len) ({				\
+	typeof(&(array)[0]) __array = (array);				\
+	typeof(len) __len = (len);					\
+	__unconst_integer_typeof(__array[0]) __element = __array[--__len]; \
+	while (__len--)							\
+		__element = op(__element, __array[__len]);		\
+	__element; })
+
+/**
+ * min_array - return minimum of values present in an array
+ * @array: array
+ * @len: array length
+ *
+ * Note that @len must not be zero (empty array).
+ */
+#define min_array(array, len) __minmax_array(min, array, len)
+
+/**
+ * max_array - return maximum of values present in an array
+ * @array: array
+ * @len: array length
+ *
+ * Note that @len must not be zero (empty array).
+ */
+#define max_array(array, len) __minmax_array(max, array, len)
+
 /**
  * clamp_t - return a value clamped to a given range using a given type
  * @type: the type of variable to use


Patches currently in stable-queue which might be from farbere at amazon.com are

queue-6.1/minmax-fix-indentation-of-__cmp_once-and-__clamp_once.patch
queue-6.1/minmax-add-in_range-macro.patch
queue-6.1/minmax-deduplicate-__unconst_integer_typeof.patch
queue-6.1/minmax-introduce-min-max-_array.patch