minmax: make generic MIN() and MAX() macros available everywhere

torvalds · gregkh · commit 7d4fa074a220 · 2025-10-02T13:40:43.000+02:00
[ Upstream commit 1a251f5 ] This just standardizes the use of MIN() and MAX() macros, with the very traditional semantics. The goal is to use these for C constant expressions and for top-level / static initializers, and so be able to simplify the min()/max() macros. These macro names were used by various kernel code - they are very traditional, after all - and all such users have been fixed up, with a few different approaches: - trivial duplicated macro definitions have been removed Note that 'trivial' here means that it's obviously kernel code that already included all the major kernel headers, and thus gets the new generic MIN/MAX macros automatically. - non-trivial duplicated macro definitions are guarded with #ifndef This is the "yes, they define their own versions, but no, the include situation is not entirely obvious, and maybe they don't get the generic version automatically" case. - strange use case #1 A couple of drivers decided that the way they want to describe their versioning is with #define MAJ 1 #define MIN 2 #define DRV_VERSION __stringify(MAJ) "." __stringify(MIN) which adds zero value and I just did my Alexander the Great impersonation, and rewrote that pointless Gordian knot as #define DRV_VERSION "1.2" instead. - strange use case #2 A couple of drivers thought that it's a good idea to have a random 'MIN' or 'MAX' define for a value or index into a table, rather than the traditional macro that takes arguments. These values were re-written as C enum's instead. The new function-line macros only expand when followed by an open parenthesis, and thus don't clash with enum use. Happily, there weren't really all that many of these cases, and a lot of users already had the pattern of using '#ifndef' guarding (or in one case just using '#undef MIN') before defining their own private version that does the same thing. I left such cases alone. 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> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/arch/um/drivers/mconsole_user.c b/arch/um/drivers/mconsole_user.c
@@ -71,7 +71,9 @@ static struct mconsole_command *mconsole_parse(struct mc_request *req)
 	return NULL;
 }
 
+#ifndef MIN
 #define MIN(a,b) ((a)<(b) ? (a):(b))
+#endif
 
 #define STRINGX(x) #x
 #define STRING(x) STRINGX(x)
diff --git a/drivers/edac/skx_common.h b/drivers/edac/skx_common.h
@@ -45,7 +45,6 @@
 #define I10NM_NUM_CHANNELS	MAX(I10NM_NUM_DDR_CHANNELS, I10NM_NUM_HBM_CHANNELS)
 #define I10NM_NUM_DIMMS		MAX(I10NM_NUM_DDR_DIMMS, I10NM_NUM_HBM_DIMMS)
 
-#define MAX(a, b)	((a) > (b) ? (a) : (b))
 #define NUM_IMC		MAX(SKX_NUM_IMC, I10NM_NUM_IMC)
 #define NUM_CHANNELS	MAX(SKX_NUM_CHANNELS, I10NM_NUM_CHANNELS)
 #define NUM_DIMMS	MAX(SKX_NUM_DIMMS, I10NM_NUM_DIMMS)
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu.h b/drivers/gpu/drm/amd/amdgpu/amdgpu.h
@@ -1258,7 +1258,9 @@ int emu_soc_asic_init(struct amdgpu_device *adev);
 
 #define amdgpu_inc_vram_lost(adev) atomic_inc(&((adev)->vram_lost_counter));
 
+#ifndef MIN
 #define MIN(X, Y) ((X) < (Y) ? (X) : (Y))
+#endif
 
 /* Common functions */
 bool amdgpu_device_has_job_running(struct amdgpu_device *adev);
diff --git a/drivers/gpu/drm/amd/display/modules/hdcp/hdcp_ddc.c b/drivers/gpu/drm/amd/display/modules/hdcp/hdcp_ddc.c
@@ -25,7 +25,9 @@
 
 #include "hdcp.h"
 
+#ifndef MIN
 #define MIN(a, b) ((a) < (b) ? (a) : (b))
+#endif
 #define HDCP_I2C_ADDR 0x3a	/* 0x74 >> 1*/
 #define KSV_READ_SIZE 0xf	/* 0x6803b - 0x6802c */
 #define HDCP_MAX_AUX_TRANSACTION_SIZE 16
diff --git a/drivers/gpu/drm/amd/pm/powerplay/hwmgr/ppevvmath.h b/drivers/gpu/drm/amd/pm/powerplay/hwmgr/ppevvmath.h
@@ -22,12 +22,18 @@
  */
 #include <asm/div64.h>
 
-#define SHIFT_AMOUNT 16 /* We multiply all original integers with 2^SHIFT_AMOUNT to get the fInt representation */
+enum ppevvmath_constants {
+	/* We multiply all original integers with 2^SHIFT_AMOUNT to get the fInt representation */
+	SHIFT_AMOUNT	= 16,
 
-#define PRECISION 5 /* Change this value to change the number of decimal places in the final output - 5 is a good default */
+	/* Change this value to change the number of decimal places in the final output - 5 is a good default */
+	PRECISION	=  5,
 
-#define SHIFTED_2 (2 << SHIFT_AMOUNT)
-#define MAX (1 << (SHIFT_AMOUNT - 1)) - 1 /* 32767 - Might change in the future */
+	SHIFTED_2	= (2 << SHIFT_AMOUNT),
+
+	/* 32767 - Might change in the future */
+	MAX		= (1 << (SHIFT_AMOUNT - 1)) - 1,
+};
 
 /* -------------------------------------------------------------------------------
  * NEW TYPE - fINT
diff --git a/drivers/gpu/drm/amd/pm/swsmu/smu11/sienna_cichlid_ppt.c b/drivers/gpu/drm/amd/pm/swsmu/smu11/sienna_cichlid_ppt.c
@@ -2081,7 +2081,9 @@ static int sienna_cichlid_display_disable_memory_clock_switch(struct smu_context
 	return ret;
 }
 
+#ifndef MAX
 #define MAX(a, b)	((a) > (b) ? (a) : (b))
+#endif
 
 static int sienna_cichlid_update_pcie_parameters(struct smu_context *smu,
 						 uint8_t pcie_gen_cap,
diff --git a/drivers/gpu/drm/amd/pm/swsmu/smu13/smu_v13_0_0_ppt.c b/drivers/gpu/drm/amd/pm/swsmu/smu13/smu_v13_0_0_ppt.c
@@ -1255,7 +1255,10 @@ static int smu_v13_0_0_get_thermal_temperature_range(struct smu_context *smu,
 	return 0;
 }
 
+#ifndef MAX
 #define MAX(a, b)	((a) > (b) ? (a) : (b))
+#endif
+
 static ssize_t smu_v13_0_0_get_gpu_metrics(struct smu_context *smu,
 					   void **table)
 {
diff --git a/drivers/gpu/drm/amd/pm/swsmu/smu13/smu_v13_0_7_ppt.c b/drivers/gpu/drm/amd/pm/swsmu/smu13/smu_v13_0_7_ppt.c
@@ -1263,7 +1263,10 @@ static int smu_v13_0_7_get_thermal_temperature_range(struct smu_context *smu,
 	return 0;
 }
 
+#ifndef MAX
 #define MAX(a, b)	((a) > (b) ? (a) : (b))
+#endif
+
 static ssize_t smu_v13_0_7_get_gpu_metrics(struct smu_context *smu,
 					   void **table)
 {
diff --git a/drivers/gpu/drm/radeon/evergreen_cs.c b/drivers/gpu/drm/radeon/evergreen_cs.c
@@ -33,8 +33,10 @@
 #include "evergreen_reg_safe.h"
 #include "cayman_reg_safe.h"
 
+#ifndef MIN
 #define MAX(a,b)                   (((a)>(b))?(a):(b))
 #define MIN(a,b)                   (((a)<(b))?(a):(b))
+#endif
 
 #define REG_SAFE_BM_SIZE ARRAY_SIZE(evergreen_reg_safe_bm)
 
diff --git a/drivers/hwmon/adt7475.c b/drivers/hwmon/adt7475.c
@@ -23,23 +23,23 @@
 #include <linux/util_macros.h>
 
 /* Indexes for the sysfs hooks */
-
-#define INPUT		0
-#define MIN		1
-#define MAX		2
-#define CONTROL		3
-#define OFFSET		3
-#define AUTOMIN		4
-#define THERM		5
-#define HYSTERSIS	6
-
+enum adt_sysfs_id {
+	INPUT		= 0,
+	MIN		= 1,
+	MAX		= 2,
+	CONTROL		= 3,
+	OFFSET		= 3,	// Dup
+	AUTOMIN		= 4,
+	THERM		= 5,
+	HYSTERSIS	= 6,
 /*
  * These are unique identifiers for the sysfs functions - unlike the
  * numbers above, these are not also indexes into an array
  */
+	ALARM		= 9,
+	FAULT		= 10,
+};
 
-#define ALARM		9
-#define FAULT		10
 
 /* 7475 Common Registers */
 
diff --git a/drivers/media/dvb-frontends/stv0367_priv.h b/drivers/media/dvb-frontends/stv0367_priv.h
@@ -25,8 +25,11 @@
 #endif
 
 /* MACRO definitions */
+#ifndef MIN
 #define MAX(X, Y) ((X) >= (Y) ? (X) : (Y))
 #define MIN(X, Y) ((X) <= (Y) ? (X) : (Y))
+#endif
+
 #define INRANGE(X, Y, Z) \
 	((((X) <= (Y)) && ((Y) <= (Z))) || \
 	(((Z) <= (Y)) && ((Y) <= (X))) ? 1 : 0)
diff --git a/drivers/net/fjes/fjes_main.c b/drivers/net/fjes/fjes_main.c
@@ -14,9 +14,7 @@
 #include "fjes.h"
 #include "fjes_trace.h"
 
-#define MAJ 1
-#define MIN 2
-#define DRV_VERSION __stringify(MAJ) "." __stringify(MIN)
+#define DRV_VERSION "1.2"
 #define DRV_NAME	"fjes"
 char fjes_driver_name[] = DRV_NAME;
 char fjes_driver_version[] = DRV_VERSION;
diff --git a/drivers/nfc/pn544/i2c.c b/drivers/nfc/pn544/i2c.c
@@ -126,8 +126,6 @@ struct pn544_i2c_fw_secure_blob {
 #define PN544_FW_CMD_RESULT_COMMAND_REJECTED 0xE0
 #define PN544_FW_CMD_RESULT_CHUNK_ERROR 0xE6
 
-#define MIN(X, Y) ((X) < (Y) ? (X) : (Y))
-
 #define PN544_FW_WRITE_BUFFER_MAX_LEN 0x9f7
 #define PN544_FW_I2C_MAX_PAYLOAD PN544_HCI_I2C_LLC_MAX_SIZE
 #define PN544_FW_I2C_WRITE_FRAME_HEADER_LEN 8
diff --git a/drivers/platform/x86/sony-laptop.c b/drivers/platform/x86/sony-laptop.c
@@ -757,7 +757,6 @@ static union acpi_object *__call_snc_method(acpi_handle handle, char *method,
 	return result;
 }
 
-#define MIN(a, b)	(a > b ? b : a)
 static int sony_nc_buffer_call(acpi_handle handle, char *name, u64 *value,
 		void *buffer, size_t buflen)
 {
diff --git a/drivers/scsi/isci/init.c b/drivers/scsi/isci/init.c
@@ -65,11 +65,7 @@
 #include "task.h"
 #include "probe_roms.h"
 
-#define MAJ 1
-#define MIN 2
-#define BUILD 0
-#define DRV_VERSION __stringify(MAJ) "." __stringify(MIN) "." \
-	__stringify(BUILD)
+#define DRV_VERSION "1.2.0"
 
 MODULE_VERSION(DRV_VERSION);
 
diff --git a/drivers/staging/media/atomisp/pci/hive_isp_css_include/math_support.h b/drivers/staging/media/atomisp/pci/hive_isp_css_include/math_support.h
@@ -31,11 +31,6 @@
 /* A => B */
 #define IMPLIES(a, b)        (!(a) || (b))
 
-/* for preprocessor and array sizing use MIN and MAX
-   otherwise use min and max */
-#define MAX(a, b)            (((a) > (b)) ? (a) : (b))
-#define MIN(a, b)            (((a) < (b)) ? (a) : (b))
-
 #define ROUND_DIV(a, b)      (((b) != 0) ? ((a) + ((b) >> 1)) / (b) : 0)
 #define CEIL_DIV(a, b)       (((b) != 0) ? ((a) + (b) - 1) / (b) : 0)
 #define CEIL_MUL(a, b)       (CEIL_DIV(a, b) * (b))
diff --git a/include/linux/minmax.h b/include/linux/minmax.h
@@ -274,6 +274,8 @@ static inline bool in_range32(u32 val, u32 start, u32 len)
  * Use these carefully: no type checking, and uses the arguments
  * multiple times. Use for obvious constants only.
  */
+#define MIN(a,b) __cmp(min,a,b)
+#define MAX(a,b) __cmp(max,a,b)
 #define MIN_T(type,a,b) __cmp(min,(type)(a),(type)(b))
 #define MAX_T(type,a,b) __cmp(max,(type)(a),(type)(b))
 
diff --git a/kernel/trace/preemptirq_delay_test.c b/kernel/trace/preemptirq_delay_test.c
@@ -34,8 +34,6 @@ MODULE_PARM_DESC(cpu_affinity, "Cpu num test is running on");
 
 static struct completion done;
 
-#define MIN(x, y) ((x) < (y) ? (x) : (y))
-
 static void busy_wait(ulong time)
 {
 	u64 start, end;
diff --git a/lib/btree.c b/lib/btree.c
@@ -43,7 +43,6 @@
 #include <linux/slab.h>
 #include <linux/module.h>
 
-#define MAX(a, b) ((a) > (b) ? (a) : (b))
 #define NODESIZE MAX(L1_CACHE_BYTES, 128)
 
 struct btree_geo {
diff --git a/lib/decompress_unlzma.c b/lib/decompress_unlzma.c
@@ -37,7 +37,9 @@
 
 #include <linux/decompress/mm.h>
 
+#ifndef MIN
 #define	MIN(a, b) (((a) < (b)) ? (a) : (b))
+#endif
 
 static long long INIT read_int(unsigned char *ptr, int size)
 {
diff --git a/mm/zsmalloc.c b/mm/zsmalloc.c
@@ -123,7 +123,6 @@
 #define ISOLATED_BITS	3
 #define MAGIC_VAL_BITS	8
 
-#define MAX(a, b) ((a) >= (b) ? (a) : (b))
 /* ZS_MIN_ALLOC_SIZE must be multiple of ZS_ALIGN */
 #define ZS_MIN_ALLOC_SIZE \
 	MAX(32, (ZS_MAX_PAGES_PER_ZSPAGE << PAGE_SHIFT >> OBJ_INDEX_BITS))
diff --git a/tools/testing/selftests/seccomp/seccomp_bpf.c b/tools/testing/selftests/seccomp/seccomp_bpf.c
@@ -60,7 +60,9 @@
 #define SKIP(s, ...)	XFAIL(s, ##__VA_ARGS__)
 #endif
 
+#ifndef MIN
 #define MIN(X, Y) ((X) < (Y) ? (X) : (Y))
+#endif
 
 #ifndef PR_SET_PTRACER
 # define PR_SET_PTRACER 0x59616d61
diff --git a/tools/testing/selftests/vm/mremap_test.c b/tools/testing/selftests/vm/mremap_test.c
@@ -22,7 +22,9 @@
 #define VALIDATION_DEFAULT_THRESHOLD 4	/* 4MB */
 #define VALIDATION_NO_THRESHOLD 0	/* Verify the entire region */
 
+#ifndef MIN
 #define MIN(X, Y) ((X) < (Y) ? (X) : (Y))
+#endif
 
 struct config {
 	unsigned long long src_alignment;

Original file line number	Diff line number	Diff line change
`@@ -71,7 +71,9 @@ static struct mconsole_command mconsole_parse(struct mc_request req)`
`71`	`71`	`return NULL;`
`72`	`72`	`}`
`73`	`73`
	`74`	`+#ifndef MIN`
`74`	`75`	`#define MIN(a,b) ((a)<(b) ? (a):(b))`
	`76`	`+#endif`
`75`	`77`
`76`	`78`	`#define STRINGX(x) #x`
`77`	`79`	`#define STRING(x) STRINGX(x)`
Original file line number	Diff line number	Diff line change
`@@ -2081,7 +2081,9 @@ static int sienna_cichlid_display_disable_memory_clock_switch(struct smu_context`
`2081`	`2081`	`return ret;`
`2082`	`2082`	`}`
`2083`	`2083`
	`2084`	`+#ifndef MAX`
`2084`	`2085`	`#define MAX(a, b) ((a) > (b) ? (a) : (b))`
	`2086`	`+#endif`
`2085`	`2087`
`2086`	`2088`	`static int sienna_cichlid_update_pcie_parameters(struct smu_context *smu,`
`2087`	`2089`	`uint8_t pcie_gen_cap,`
Original file line number	Diff line number	Diff line change
`@@ -1255,7 +1255,10 @@ static int smu_v13_0_0_get_thermal_temperature_range(struct smu_context *smu,`
`1255`	`1255`	`return 0;`
`1256`	`1256`	`}`
`1257`	`1257`
	`1258`	`+#ifndef MAX`
`1258`	`1259`	`#define MAX(a, b) ((a) > (b) ? (a) : (b))`
	`1260`	`+#endif`
	`1261`	`+`
`1259`	`1262`	`static ssize_t smu_v13_0_0_get_gpu_metrics(struct smu_context *smu,`
`1260`	`1263`	`void **table)`
`1261`	`1264`	`{`
Original file line number	Diff line number	Diff line change
`@@ -1263,7 +1263,10 @@ static int smu_v13_0_7_get_thermal_temperature_range(struct smu_context *smu,`
`1263`	`1263`	`return 0;`
`1264`	`1264`	`}`
`1265`	`1265`
	`1266`	`+#ifndef MAX`
`1266`	`1267`	`#define MAX(a, b) ((a) > (b) ? (a) : (b))`
	`1268`	`+#endif`
	`1269`	`+`
`1267`	`1270`	`static ssize_t smu_v13_0_7_get_gpu_metrics(struct smu_context *smu,`
`1268`	`1271`	`void **table)`
`1269`	`1272`	`{`