linux-sparse.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Eliav Farber <farbere@amazon.com>
To: <richard@nod.at>, <anton.ivanov@cambridgegreys.com>,
	<johannes@sipsolutions.net>, <dave.hansen@linux.intel.com>,
	<luto@kernel.org>, <peterz@infradead.org>, <tglx@linutronix.de>,
	<mingo@redhat.com>, <bp@alien8.de>, <x86@kernel.org>,
	<hpa@zytor.com>, <tony.luck@intel.com>, <qiuxu.zhuo@intel.com>,
	<james.morse@arm.com>, <mchehab@kernel.org>, <rric@kernel.org>,
	<harry.wentland@amd.com>, <sunpeng.li@amd.com>,
	<Rodrigo.Siqueira@amd.com>, <alexander.deucher@amd.com>,
	<christian.koenig@amd.com>, <Xinhui.Pan@amd.com>,
	<airlied@gmail.com>, <daniel@ffwll.ch>, <evan.quan@amd.com>,
	<maarten.lankhorst@linux.intel.com>, <mripard@kernel.org>,
	<tzimmermann@suse.de>, <jdelvare@suse.com>, <linux@roeck-us.net>,
	<linus.walleij@linaro.org>, <dmitry.torokhov@gmail.com>,
	<wens@csie.org>, <jernej.skrabec@gmail.com>,
	<samuel@sholland.org>, <agk@redhat.com>, <snitzer@kernel.org>,
	<dm-devel@lists.linux.dev>, <mailhol.vincent@wanadoo.fr>,
	<wg@grandegger.com>, <mkl@pengutronix.de>, <davem@davemloft.net>,
	<edumazet@google.com>, <kuba@kernel.org>, <pabeni@redhat.com>,
	<alexandre.torgue@foss.st.com>, <joabreu@synopsys.com>,
	<mcoquelin.stm32@gmail.com>, <krzysztof.kozlowski@linaro.org>,
	<malattia@linux.it>, <hdegoede@redhat.com>,
	<ilpo.jarvinen@linux.intel.com>, <markgross@kernel.org>,
	<artur.paszkiewicz@intel.com>, <jejb@linux.ibm.com>,
	<martin.petersen@oracle.com>, <sakari.ailus@linux.intel.com>,
	<gregkh@linuxfoundation.org>, <clm@fb.com>,
	<josef@toxicpanda.com>, <dsterba@suse.com>,
	<luc.vanoostenryck@gmail.com>, <rostedt@goodmis.org>,
	<mhiramat@kernel.org>, <pmladek@suse.com>,
	<andriy.shevchenko@linux.intel.com>, <linux@rasmusvillemoes.dk>,
	<senozhatsky@chromium.org>, <minchan@kernel.org>,
	<akpm@linux-foundation.org>, <dsahern@kernel.org>,
	<shuah@kernel.org>, <keescook@chromium.org>, <wad@chromium.org>,
	<farbere@amazon.com>, <David.Laight@ACULAB.COM>,
	<arnd@kernel.org>, <linux-um@lists.infradead.org>,
	<linux-kernel@vger.kernel.org>, <linux-edac@vger.kernel.org>,
	<amd-gfx@lists.freedesktop.org>,
	<dri-devel@lists.freedesktop.org>, <linux-hwmon@vger.kernel.org>,
	<linux-input@vger.kernel.org>,
	<linux-arm-kernel@lists.infradead.org>,
	<linux-sunxi@lists.linux.dev>, <linux-media@vger.kernel.org>,
	<linux-can@vger.kernel.org>, <netdev@vger.kernel.org>,
	<linux-stm32@st-md-mailman.stormreply.com>,
	<platform-driver-x86@vger.kernel.org>,
	<linux-scsi@vger.kernel.org>, <linux-staging@lists.linux.dev>,
	<linux-btrfs@vger.kernel.org>, <linux-sparse@vger.kernel.org>,
	<linux-trace-kernel@vger.kernel.org>, <linux-mm@kvack.org>,
	<linux-kselftest@vger.kernel.org>, <bpf@vger.kernel.org>,
	<stable@vger.kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>,
	David Laight <David.Laight@aculab.com>,
	Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Subject: [PATCH 03/15 6.6.y] minmax: add a few more MIN_T/MAX_T users
Date: Mon, 22 Sep 2025 10:32:29 +0000	[thread overview]
Message-ID: <20250922103241.16213-4-farbere@amazon.com> (raw)
In-Reply-To: <20250922103241.16213-1-farbere@amazon.com>

From: Linus Torvalds <torvalds@linux-foundation.org>

[ Upstream commit 4477b39c32fdc03363affef4b11d48391e6dc9ff ]

Commit 3a7e02c040b1 ("minmax: avoid overly complicated constant
expressions in VM code") added the simpler MIN_T/MAX_T macros in order
to avoid some excessive expansion from the rather complicated regular
min/max macros.

The complexity of those macros stems from two issues:

 (a) trying to use them in situations that require a C constant
     expression (in static initializers and for array sizes)

 (b) the type sanity checking

and MIN_T/MAX_T avoids both of these issues.

Now, in the whole (long) discussion about all this, it was pointed out
that the whole type sanity checking is entirely unnecessary for
min_t/max_t which get a fixed type that the comparison is done in.

But that still leaves min_t/max_t unnecessarily complicated due to
worries about the C constant expression case.

However, it turns out that there really aren't very many cases that use
min_t/max_t for this, and we can just force-convert those.

This does exactly that.

Which in turn will then allow for much simpler implementations of
min_t()/max_t().  All the usual "macros in all upper case will evaluate
the arguments multiple times" rules apply.

We should do all the same things for the regular min/max() vs MIN/MAX()
cases, but that has the added complexity of various drivers defining
their own local versions of MIN/MAX, so that needs another level of
fixes first.

Link: https://lore.kernel.org/all/b47fad1d0cf8449886ad148f8c013dae@AcuMS.aculab.com/
Cc: David Laight <David.Laight@aculab.com>
Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Eliav Farber <farbere@amazon.com>
---
 arch/x86/mm/pgtable.c                             | 2 +-
 drivers/edac/sb_edac.c                            | 4 ++--
 drivers/gpu/drm/drm_color_mgmt.c                  | 2 +-
 drivers/md/dm-integrity.c                         | 6 +++---
 drivers/net/ethernet/stmicro/stmmac/stmmac_main.c | 2 +-
 net/ipv4/proc.c                                   | 2 +-
 net/ipv6/proc.c                                   | 2 +-
 7 files changed, 10 insertions(+), 10 deletions(-)

diff --git a/arch/x86/mm/pgtable.c b/arch/x86/mm/pgtable.c
index b18f5a71e679..98aa303ad054 100644
--- a/arch/x86/mm/pgtable.c
+++ b/arch/x86/mm/pgtable.c
@@ -107,7 +107,7 @@ static inline void pgd_list_del(pgd_t *pgd)
 #define UNSHARED_PTRS_PER_PGD				\
 	(SHARED_KERNEL_PMD ? KERNEL_PGD_BOUNDARY : PTRS_PER_PGD)
 #define MAX_UNSHARED_PTRS_PER_PGD			\
-	max_t(size_t, KERNEL_PGD_BOUNDARY, PTRS_PER_PGD)
+	MAX_T(size_t, KERNEL_PGD_BOUNDARY, PTRS_PER_PGD)
 
 
 static void pgd_set_mm(pgd_t *pgd, struct mm_struct *mm)
diff --git a/drivers/edac/sb_edac.c b/drivers/edac/sb_edac.c
index 0c779a0326b6..6c3a40e6f4c6 100644
--- a/drivers/edac/sb_edac.c
+++ b/drivers/edac/sb_edac.c
@@ -109,8 +109,8 @@ static const u32 knl_interleave_list[] = {
 	0x104, 0x10c, 0x114, 0x11c,   /* 20-23 */
 };
 #define MAX_INTERLEAVE							\
-	(max_t(unsigned int, ARRAY_SIZE(sbridge_interleave_list),	\
-	       max_t(unsigned int, ARRAY_SIZE(ibridge_interleave_list),	\
+	(MAX_T(unsigned int, ARRAY_SIZE(sbridge_interleave_list),	\
+	       MAX_T(unsigned int, ARRAY_SIZE(ibridge_interleave_list),	\
 		     ARRAY_SIZE(knl_interleave_list))))
 
 struct interleave_pkg {
diff --git a/drivers/gpu/drm/drm_color_mgmt.c b/drivers/gpu/drm/drm_color_mgmt.c
index d021497841b8..3969dc548cff 100644
--- a/drivers/gpu/drm/drm_color_mgmt.c
+++ b/drivers/gpu/drm/drm_color_mgmt.c
@@ -532,7 +532,7 @@ int drm_plane_create_color_properties(struct drm_plane *plane,
 {
 	struct drm_device *dev = plane->dev;
 	struct drm_property *prop;
-	struct drm_prop_enum_list enum_list[max_t(int, DRM_COLOR_ENCODING_MAX,
+	struct drm_prop_enum_list enum_list[MAX_T(int, DRM_COLOR_ENCODING_MAX,
 						       DRM_COLOR_RANGE_MAX)];
 	int i, len;
 
diff --git a/drivers/md/dm-integrity.c b/drivers/md/dm-integrity.c
index 1e27a5bce2d9..0bd76f8d4dc6 100644
--- a/drivers/md/dm-integrity.c
+++ b/drivers/md/dm-integrity.c
@@ -1794,7 +1794,7 @@ static void integrity_metadata(struct work_struct *w)
 		struct bio *bio = dm_bio_from_per_bio_data(dio, sizeof(struct dm_integrity_io));
 		char *checksums;
 		unsigned int extra_space = unlikely(digest_size > ic->tag_size) ? digest_size - ic->tag_size : 0;
-		char checksums_onstack[max_t(size_t, HASH_MAX_DIGESTSIZE, MAX_TAG_SIZE)];
+		char checksums_onstack[MAX_T(size_t, HASH_MAX_DIGESTSIZE, MAX_TAG_SIZE)];
 		sector_t sector;
 		unsigned int sectors_to_process;
 
@@ -2073,7 +2073,7 @@ static bool __journal_read_write(struct dm_integrity_io *dio, struct bio *bio,
 				} while (++s < ic->sectors_per_block);
 #ifdef INTERNAL_VERIFY
 				if (ic->internal_hash) {
-					char checksums_onstack[max_t(size_t, HASH_MAX_DIGESTSIZE, MAX_TAG_SIZE)];
+					char checksums_onstack[MAX_T(size_t, HASH_MAX_DIGESTSIZE, MAX_TAG_SIZE)];
 
 					integrity_sector_checksum(ic, logical_sector, mem + bv.bv_offset, checksums_onstack);
 					if (unlikely(memcmp(checksums_onstack, journal_entry_tag(ic, je), ic->tag_size))) {
@@ -2638,7 +2638,7 @@ static void do_journal_write(struct dm_integrity_c *ic, unsigned int write_start
 				    unlikely(from_replay) &&
 #endif
 				    ic->internal_hash) {
-					char test_tag[max_t(size_t, HASH_MAX_DIGESTSIZE, MAX_TAG_SIZE)];
+					char test_tag[MAX_T(size_t, HASH_MAX_DIGESTSIZE, MAX_TAG_SIZE)];
 
 					integrity_sector_checksum(ic, sec + ((l - j) << ic->sb->log2_sectors_per_block),
 								  (char *)access_journal_data(ic, i, l), test_tag);
diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
index ff5389a8efc3..f3155d69a013 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
@@ -2841,7 +2841,7 @@ static void stmmac_dma_interrupt(struct stmmac_priv *priv)
 	u32 channels_to_check = tx_channel_count > rx_channel_count ?
 				tx_channel_count : rx_channel_count;
 	u32 chan;
-	int status[max_t(u32, MTL_MAX_TX_QUEUES, MTL_MAX_RX_QUEUES)];
+	int status[MAX_T(u32, MTL_MAX_TX_QUEUES, MTL_MAX_RX_QUEUES)];
 
 	/* Make sure we never check beyond our status buffer. */
 	if (WARN_ON_ONCE(channels_to_check > ARRAY_SIZE(status)))
diff --git a/net/ipv4/proc.c b/net/ipv4/proc.c
index a85b0aba3646..b444767b15a5 100644
--- a/net/ipv4/proc.c
+++ b/net/ipv4/proc.c
@@ -43,7 +43,7 @@
 #include <net/sock.h>
 #include <net/raw.h>
 
-#define TCPUDP_MIB_MAX max_t(u32, UDP_MIB_MAX, TCP_MIB_MAX)
+#define TCPUDP_MIB_MAX MAX_T(u32, UDP_MIB_MAX, TCP_MIB_MAX)
 
 /*
  *	Report socket allocation statistics [mea@utu.fi]
diff --git a/net/ipv6/proc.c b/net/ipv6/proc.c
index 6d1d9221649d..752327b10dde 100644
--- a/net/ipv6/proc.c
+++ b/net/ipv6/proc.c
@@ -27,7 +27,7 @@
 #include <net/ipv6.h>
 
 #define MAX4(a, b, c, d) \
-	max_t(u32, max_t(u32, a, b), max_t(u32, c, d))
+	MAX_T(u32, MAX_T(u32, a, b), MAX_T(u32, c, d))
 #define SNMP_MIB_MAX MAX4(UDP_MIB_MAX, TCP_MIB_MAX, \
 			IPSTATS_MIB_MAX, ICMP_MIB_MAX)
 
-- 
2.47.3


  parent reply	other threads:[~2025-09-22 10:34 UTC|newest]

Thread overview: 16+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2025-09-22 10:32 [PATCH 00/15 v6.6.y] Backport minmax.h updates from v6.17-rc7 Eliav Farber
2025-09-22 10:32 ` [PATCH 01/15 6.6.y] minmax: avoid overly complicated constant expressions in VM code Eliav Farber
2025-09-22 10:32 ` [PATCH 02/15 6.6.y] minmax: simplify and clarify min_t()/max_t() implementation Eliav Farber
2025-09-22 10:32 ` Eliav Farber [this message]
2025-09-22 10:32 ` [PATCH 04/15 6.6.y] minmax: make generic MIN() and MAX() macros available everywhere Eliav Farber
2025-09-22 10:32 ` [PATCH 05/15 6.6.y] minmax: simplify min()/max()/clamp() implementation Eliav Farber
2025-09-22 10:32 ` [PATCH 06/15 6.6.y] minmax: don't use max() in situations that want a C constant expression Eliav Farber
2025-09-22 10:32 ` [PATCH 07/15 6.6.y] minmax: improve macro expansion and type checking Eliav Farber
2025-09-22 10:32 ` [PATCH 08/15 6.6.y] minmax: fix up min3() and max3() too Eliav Farber
2025-09-22 10:32 ` [PATCH 09/15 6.6.y] minmax.h: add whitespace around operators and after commas Eliav Farber
2025-09-22 10:32 ` [PATCH 10/15 6.6.y] minmax.h: update some comments Eliav Farber
2025-09-22 10:32 ` [PATCH 11/15 6.6.y] minmax.h: reduce the #define expansion of min(), max() and clamp() Eliav Farber
2025-09-22 10:32 ` [PATCH 12/15 6.6.y] minmax.h: use BUILD_BUG_ON_MSG() for the lo < hi test in clamp() Eliav Farber
2025-09-22 10:32 ` [PATCH 13/15 6.6.y] minmax.h: move all the clamp() definitions after the min/max() ones Eliav Farber
2025-09-22 10:32 ` [PATCH 14/15 6.6.y] minmax.h: simplify the variants of clamp() Eliav Farber
2025-09-22 10:32 ` [PATCH 15/15 6.6.y] minmax.h: remove some #defines that are only expanded once Eliav Farber

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20250922103241.16213-4-farbere@amazon.com \
    --to=farbere@amazon.com \
    --cc=David.Laight@ACULAB.COM \
    --cc=Rodrigo.Siqueira@amd.com \
    --cc=Xinhui.Pan@amd.com \
    --cc=agk@redhat.com \
    --cc=airlied@gmail.com \
    --cc=akpm@linux-foundation.org \
    --cc=alexander.deucher@amd.com \
    --cc=alexandre.torgue@foss.st.com \
    --cc=amd-gfx@lists.freedesktop.org \
    --cc=andriy.shevchenko@linux.intel.com \
    --cc=anton.ivanov@cambridgegreys.com \
    --cc=arnd@kernel.org \
    --cc=artur.paszkiewicz@intel.com \
    --cc=bp@alien8.de \
    --cc=bpf@vger.kernel.org \
    --cc=christian.koenig@amd.com \
    --cc=clm@fb.com \
    --cc=daniel@ffwll.ch \
    --cc=dave.hansen@linux.intel.com \
    --cc=davem@davemloft.net \
    --cc=dm-devel@lists.linux.dev \
    --cc=dmitry.torokhov@gmail.com \
    --cc=dri-devel@lists.freedesktop.org \
    --cc=dsahern@kernel.org \
    --cc=dsterba@suse.com \
    --cc=edumazet@google.com \
    --cc=evan.quan@amd.com \
    --cc=gregkh@linuxfoundation.org \
    --cc=harry.wentland@amd.com \
    --cc=hdegoede@redhat.com \
    --cc=hpa@zytor.com \
    --cc=ilpo.jarvinen@linux.intel.com \
    --cc=james.morse@arm.com \
    --cc=jdelvare@suse.com \
    --cc=jejb@linux.ibm.com \
    --cc=jernej.skrabec@gmail.com \
    --cc=joabreu@synopsys.com \
    --cc=johannes@sipsolutions.net \
    --cc=josef@toxicpanda.com \
    --cc=keescook@chromium.org \
    --cc=krzysztof.kozlowski@linaro.org \
    --cc=kuba@kernel.org \
    --cc=linus.walleij@linaro.org \
    --cc=linux-arm-kernel@lists.infradead.org \
    --cc=linux-btrfs@vger.kernel.org \
    --cc=linux-can@vger.kernel.org \
    --cc=linux-edac@vger.kernel.org \
    --cc=linux-hwmon@vger.kernel.org \
    --cc=linux-input@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-kselftest@vger.kernel.org \
    --cc=linux-media@vger.kernel.org \
    --cc=linux-mm@kvack.org \
    --cc=linux-scsi@vger.kernel.org \
    --cc=linux-sparse@vger.kernel.org \
    --cc=linux-staging@lists.linux.dev \
    --cc=linux-stm32@st-md-mailman.stormreply.com \
    --cc=linux-sunxi@lists.linux.dev \
    --cc=linux-trace-kernel@vger.kernel.org \
    --cc=linux-um@lists.infradead.org \
    --cc=linux@rasmusvillemoes.dk \
    --cc=linux@roeck-us.net \
    --cc=lorenzo.stoakes@oracle.com \
    --cc=luc.vanoostenryck@gmail.com \
    --cc=luto@kernel.org \
    --cc=maarten.lankhorst@linux.intel.com \
    --cc=mailhol.vincent@wanadoo.fr \
    --cc=malattia@linux.it \
    --cc=markgross@kernel.org \
    --cc=martin.petersen@oracle.com \
    --cc=mchehab@kernel.org \
    --cc=mcoquelin.stm32@gmail.com \
    --cc=mhiramat@kernel.org \
    --cc=minchan@kernel.org \
    --cc=mingo@redhat.com \
    --cc=mkl@pengutronix.de \
    --cc=mripard@kernel.org \
    --cc=netdev@vger.kernel.org \
    --cc=pabeni@redhat.com \
    --cc=peterz@infradead.org \
    --cc=platform-driver-x86@vger.kernel.org \
    --cc=pmladek@suse.com \
    --cc=qiuxu.zhuo@intel.com \
    --cc=richard@nod.at \
    --cc=rostedt@goodmis.org \
    --cc=rric@kernel.org \
    --cc=sakari.ailus@linux.intel.com \
    --cc=samuel@sholland.org \
    --cc=senozhatsky@chromium.org \
    --cc=shuah@kernel.org \
    --cc=snitzer@kernel.org \
    --cc=stable@vger.kernel.org \
    --cc=sunpeng.li@amd.com \
    --cc=tglx@linutronix.de \
    --cc=tony.luck@intel.com \
    --cc=torvalds@linux-foundation.org \
    --cc=tzimmermann@suse.de \
    --cc=wad@chromium.org \
    --cc=wens@csie.org \
    --cc=wg@grandegger.com \
    --cc=x86@kernel.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).