Commit e8c97af0 authored by Randy Dunlap's avatar Randy Dunlap Committed by Linus Torvalds

linux/kernel.h: add/correct kernel-doc notation

Add kernel-doc notation for some macros.  Correct kernel-doc comments &
typos for a few macros.

Link: http://lkml.kernel.org/r/76fa1403-1511-be4c-e9c4-456b43edfad3@infradead.orgSigned-off-by: default avatarRandy Dunlap <rdunlap@infradead.org>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent e65c62b1
......@@ -44,6 +44,12 @@
#define STACK_MAGIC 0xdeadbeef
/**
* REPEAT_BYTE - repeat the value @x multiple times as an unsigned long value
* @x: value to repeat
*
* NOTE: @x is not checked for > 0xff; larger values produce odd results.
*/
#define REPEAT_BYTE(x) ((~0ul / 0xff) * (x))
/* @a is a power of 2 value */
......@@ -57,6 +63,10 @@
#define READ 0
#define WRITE 1
/**
* ARRAY_SIZE - get the number of elements in array @arr
* @arr: array to be sized
*/
#define ARRAY_SIZE(arr) (sizeof(arr) / sizeof((arr)[0]) + __must_be_array(arr))
#define u64_to_user_ptr(x) ( \
......@@ -76,7 +86,15 @@
#define round_up(x, y) ((((x)-1) | __round_mask(x, y))+1)
#define round_down(x, y) ((x) & ~__round_mask(x, y))
/**
* FIELD_SIZEOF - get the size of a struct's field
* @t: the target struct
* @f: the target struct's field
* Return: the size of @f in the struct definition without having a
* declared instance of @t.
*/
#define FIELD_SIZEOF(t, f) (sizeof(((t*)0)->f))
#define DIV_ROUND_UP __KERNEL_DIV_ROUND_UP
#define DIV_ROUND_DOWN_ULL(ll, d) \
......@@ -107,7 +125,7 @@
/*
* Divide positive or negative dividend by positive or negative divisor
* and round to closest integer. Result is undefined for negative
* divisors if he dividend variable type is unsigned and for negative
* divisors if the dividend variable type is unsigned and for negative
* dividends if the divisor variable type is unsigned.
*/
#define DIV_ROUND_CLOSEST(x, divisor)( \
......@@ -247,13 +265,13 @@ extern int _cond_resched(void);
* @ep_ro: right open interval endpoint
*
* Perform a "reciprocal multiplication" in order to "scale" a value into
* range [0, ep_ro), where the upper interval endpoint is right-open.
* range [0, @ep_ro), where the upper interval endpoint is right-open.
* This is useful, e.g. for accessing a index of an array containing
* ep_ro elements, for example. Think of it as sort of modulus, only that
* @ep_ro elements, for example. Think of it as sort of modulus, only that
* the result isn't that of modulo. ;) Note that if initial input is a
* small value, then result will return 0.
*
* Return: a result based on val in interval [0, ep_ro).
* Return: a result based on @val in interval [0, @ep_ro).
*/
static inline u32 reciprocal_scale(u32 val, u32 ep_ro)
{
......@@ -618,8 +636,8 @@ do { \
* trace_printk - printf formatting in the ftrace buffer
* @fmt: the printf format for printing
*
* Note: __trace_printk is an internal function for trace_printk and
* the @ip is passed in via the trace_printk macro.
* Note: __trace_printk is an internal function for trace_printk() and
* the @ip is passed in via the trace_printk() macro.
*
* This function allows a kernel developer to debug fast path sections
* that printk is not appropriate for. By scattering in various
......@@ -629,7 +647,7 @@ do { \
* This is intended as a debugging tool for the developer only.
* Please refrain from leaving trace_printks scattered around in
* your code. (Extra memory is used for special buffers that are
* allocated when trace_printk() is used)
* allocated when trace_printk() is used.)
*
* A little optization trick is done here. If there's only one
* argument, there's no need to scan the string for printf formats.
......@@ -681,7 +699,7 @@ int __trace_printk(unsigned long ip, const char *fmt, ...);
* the @ip is passed in via the trace_puts macro.
*
* This is similar to trace_printk() but is made for those really fast
* paths that a developer wants the least amount of "Heisenbug" affects,
* paths that a developer wants the least amount of "Heisenbug" effects,
* where the processing of the print format is still too much.
*
* This function allows a kernel developer to debug fast path sections
......@@ -692,7 +710,7 @@ int __trace_printk(unsigned long ip, const char *fmt, ...);
* This is intended as a debugging tool for the developer only.
* Please refrain from leaving trace_puts scattered around in
* your code. (Extra memory is used for special buffers that are
* allocated when trace_puts() is used)
* allocated when trace_puts() is used.)
*
* Returns: 0 if nothing was written, positive # if string was.
* (1 when __trace_bputs is used, strlen(str) when __trace_puts is used)
......@@ -771,6 +789,12 @@ static inline void ftrace_dump(enum ftrace_dump_mode oops_dump_mode) { }
t2 min2 = (y); \
(void) (&min1 == &min2); \
min1 < min2 ? min1 : min2; })
/**
* min - return minimum of two values of the same or compatible types
* @x: first value
* @y: second value
*/
#define min(x, y) \
__min(typeof(x), typeof(y), \
__UNIQUE_ID(min1_), __UNIQUE_ID(min2_), \
......@@ -781,12 +805,31 @@ static inline void ftrace_dump(enum ftrace_dump_mode oops_dump_mode) { }
t2 max2 = (y); \
(void) (&max1 == &max2); \
max1 > max2 ? max1 : max2; })
/**
* max - return maximum of two values of the same or compatible types
* @x: first value
* @y: second value
*/
#define max(x, y) \
__max(typeof(x), typeof(y), \
__UNIQUE_ID(max1_), __UNIQUE_ID(max2_), \
x, y)
/**
* min3 - return minimum of three values
* @x: first value
* @y: second value
* @z: third value
*/
#define min3(x, y, z) min((typeof(x))min(x, y), z)
/**
* max3 - return maximum of three values
* @x: first value
* @y: second value
* @z: third value
*/
#define max3(x, y, z) max((typeof(x))max(x, y), z)
/**
......@@ -805,8 +848,8 @@ static inline void ftrace_dump(enum ftrace_dump_mode oops_dump_mode) { }
* @lo: lowest allowable value
* @hi: highest allowable value
*
* This macro does strict typechecking of lo/hi to make sure they are of the
* same type as val. See the unnecessary pointer comparisons.
* This macro does strict typechecking of @lo/@hi to make sure they are of the
* same type as @val. See the unnecessary pointer comparisons.
*/
#define clamp(val, lo, hi) min((typeof(val))max(val, lo), hi)
......@@ -816,11 +859,24 @@ static inline void ftrace_dump(enum ftrace_dump_mode oops_dump_mode) { }
*
* Or not use min/max/clamp at all, of course.
*/
/**
* min_t - return minimum of two values, using the specified type
* @type: data type to use
* @x: first value
* @y: second value
*/
#define min_t(type, x, y) \
__min(type, type, \
__UNIQUE_ID(min1_), __UNIQUE_ID(min2_), \
x, y)
/**
* max_t - return maximum of two values, using the specified type
* @type: data type to use
* @x: first value
* @y: second value
*/
#define max_t(type, x, y) \
__max(type, type, \
__UNIQUE_ID(min1_), __UNIQUE_ID(min2_), \
......@@ -834,7 +890,7 @@ static inline void ftrace_dump(enum ftrace_dump_mode oops_dump_mode) { }
* @hi: maximum allowable value
*
* This macro does no typechecking and uses temporary variables of type
* 'type' to make all the comparisons.
* @type to make all the comparisons.
*/
#define clamp_t(type, val, lo, hi) min_t(type, max_t(type, val, lo), hi)
......@@ -845,15 +901,17 @@ static inline void ftrace_dump(enum ftrace_dump_mode oops_dump_mode) { }
* @hi: maximum allowable value
*
* This macro does no typechecking and uses temporary variables of whatever
* type the input argument 'val' is. This is useful when val is an unsigned
* type and min and max are literals that will otherwise be assigned a signed
* type the input argument @val is. This is useful when @val is an unsigned
* type and @lo and @hi are literals that will otherwise be assigned a signed
* integer type.
*/
#define clamp_val(val, lo, hi) clamp_t(typeof(val), val, lo, hi)
/*
* swap - swap value of @a and @b
/**
* swap - swap values of @a and @b
* @a: first value
* @b: second value
*/
#define swap(a, b) \
do { typeof(a) __tmp = (a); (a) = (b); (b) = __tmp; } while (0)
......
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