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minmax: make generic MIN() and MAX() macros available everywhere
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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 <[email protected]>
Cc: Lorenzo Stoakes <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
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torvalds committed Jul 28, 2024
1 parent 8400291 commit 1a251f5
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Showing 20 changed files with 43 additions and 38 deletions.
2 changes: 2 additions & 0 deletions arch/um/drivers/mconsole_user.c
Original file line number Diff line number Diff line change
Expand Up @@ -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)
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1 change: 0 additions & 1 deletion drivers/edac/skx_common.h
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Expand Up @@ -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)
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2 changes: 2 additions & 0 deletions drivers/gpu/drm/amd/display/dc/core/dc_stream.c
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Expand Up @@ -35,8 +35,10 @@
#include "dc_stream_priv.h"

#define DC_LOGGER dc->ctx->logger
#ifndef MIN
#define MIN(X, Y) ((X) < (Y) ? (X) : (Y))
#define MAX(x, y) ((x > y) ? x : y)
#endif

/*******************************************************************************
* Private functions
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2 changes: 2 additions & 0 deletions drivers/gpu/drm/amd/display/modules/hdcp/hdcp_ddc.c
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Expand Up @@ -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
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14 changes: 10 additions & 4 deletions drivers/gpu/drm/amd/pm/powerplay/hwmgr/ppevvmath.h
Original file line number Diff line number Diff line change
Expand Up @@ -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
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2 changes: 2 additions & 0 deletions drivers/gpu/drm/radeon/evergreen_cs.c
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Expand Up @@ -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)

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24 changes: 12 additions & 12 deletions drivers/hwmon/adt7475.c
Original file line number Diff line number Diff line change
Expand Up @@ -22,23 +22,23 @@
#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 */

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3 changes: 3 additions & 0 deletions drivers/media/dvb-frontends/stv0367_priv.h
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Expand Up @@ -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)
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4 changes: 1 addition & 3 deletions drivers/net/fjes/fjes_main.c
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Expand Up @@ -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;
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2 changes: 0 additions & 2 deletions drivers/nfc/pn544/i2c.c
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Expand Up @@ -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
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1 change: 0 additions & 1 deletion drivers/platform/x86/sony-laptop.c
Original file line number Diff line number Diff line change
Expand Up @@ -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)
{
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6 changes: 1 addition & 5 deletions drivers/scsi/isci/init.c
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Expand Up @@ -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);

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Original file line number Diff line number Diff line change
Expand Up @@ -22,11 +22,6 @@
/* force a value to a lower even value */
#define EVEN_FLOOR(x) ((x) & ~1)

/* 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 CEIL_DIV(a, b) (((b) != 0) ? ((a) + (b) - 1) / (b) : 0)
#define CEIL_MUL(a, b) (CEIL_DIV(a, b) * (b))
#define CEIL_MUL2(a, b) (((a) + (b) - 1) & ~((b) - 1))
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2 changes: 2 additions & 0 deletions include/linux/minmax.h
Original file line number Diff line number Diff line change
Expand Up @@ -277,6 +277,8 @@ 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))

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2 changes: 0 additions & 2 deletions kernel/trace/preemptirq_delay_test.c
Original file line number Diff line number Diff line change
Expand Up @@ -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;
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1 change: 0 additions & 1 deletion lib/btree.c
Original file line number Diff line number Diff line change
Expand Up @@ -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 {
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2 changes: 2 additions & 0 deletions lib/decompress_unlzma.c
Original file line number Diff line number Diff line change
Expand Up @@ -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)
{
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2 changes: 0 additions & 2 deletions mm/zsmalloc.c
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Expand Up @@ -120,8 +120,6 @@
#define CLASS_BITS 8
#define MAGIC_VAL_BITS 8

#define MAX(a, b) ((a) >= (b) ? (a) : (b))

#define ZS_MAX_PAGES_PER_ZSPAGE (_AC(CONFIG_ZSMALLOC_CHAIN_SIZE, UL))

/* ZS_MIN_ALLOC_SIZE must be multiple of ZS_ALIGN */
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2 changes: 2 additions & 0 deletions tools/testing/selftests/mm/mremap_test.c
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Expand Up @@ -22,8 +22,10 @@
#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))
#define MAX(X, Y) ((X) > (Y) ? (X) : (Y))
#endif
#define SIZE_MB(m) ((size_t)m * (1024 * 1024))
#define SIZE_KB(k) ((size_t)k * 1024)

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2 changes: 2 additions & 0 deletions tools/testing/selftests/seccomp/seccomp_bpf.c
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Expand Up @@ -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
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