Commit 4d42c447 authored by Andy Shevchenko's avatar Andy Shevchenko Committed by Alexandre Belloni
Browse files

lib/vsprintf: Print time and date in human readable format via %pt 



There are users which print time and date represented by content of
struct rtc_time in human readable format.

Instead of open coding that each time introduce %ptR[dt][r] specifier.

Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Guan Xuetao <gxt@mprc.pku.edu.cn>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jason Wessel <jason.wessel@windriver.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Jonathan Hunter <jonathanh@nvidia.com>
Cc: Krzysztof Kozlowski <krzk@kernel.org>
Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
Cc: Thierry Reding <thierry.reding@gmail.com>
Cc: Petr Mladek <pmladek@suse.com>
Signed-off-by: default avatarAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: default avatarPetr Mladek <pmladek@suse.com>
Signed-off-by: default avatarAlexandre Belloni <alexandre.belloni@bootlin.com>
parent 8c4cf161

Documentation/core-api/printk-formats.rst

+18 −0
Original line number Diff line number Diff line
@@ -412,6 +412,24 @@ Examples:: 


Passed by reference.



Time and date (struct rtc_time)

-------------------------------



::



	%ptR		YYYY-mm-ddTHH:MM:SS

	%ptRd		YYYY-mm-dd

	%ptRt		HH:MM:SS

	%ptR[dt][r]



For printing date and time as represented by struct rtc_time structure in

human readable format.



By default year will be incremented by 1900 and month by 1. Use %ptRr (raw)

to suppress this behaviour.



Passed by reference.



struct clk

----------

lib/test_printf.c

+58 −3
Original line number Diff line number Diff line
@@ -9,6 +9,7 @@ 
#include <linux/module.h>

#include <linux/printk.h>

#include <linux/random.h>

#include <linux/rtc.h>

#include <linux/slab.h>

#include <linux/string.h>
@@ -249,12 +250,11 @@ plain_format(void) 
#endif	/* BITS_PER_LONG == 64 */



static int __init

plain_hash(void)

plain_hash_to_buffer(const void *p, char *buf, size_t len)

{

	char buf[PLAIN_BUF_SIZE];

	int nchars;



	nchars = snprintf(buf, PLAIN_BUF_SIZE, "%p", PTR);

	nchars = snprintf(buf, len, "%p", p);



	if (nchars != PTR_WIDTH)

		return -1;
@@ -265,6 +265,20 @@ plain_hash(void) 
		return 0;

	}



	return 0;

}





static int __init

plain_hash(void)

{

	char buf[PLAIN_BUF_SIZE];

	int ret;



	ret = plain_hash_to_buffer(PTR, buf, PLAIN_BUF_SIZE);

	if (ret)

		return ret;



	if (strncmp(buf, PTR_STR, PTR_WIDTH) == 0)

		return -1;
@@ -294,6 +308,23 @@ plain(void) 
	}

}



static void __init

test_hashed(const char *fmt, const void *p)

{

	char buf[PLAIN_BUF_SIZE];

	int ret;



	/*

	 * No need to increase failed test counter since this is assumed

	 * to be called after plain().

	 */

	ret = plain_hash_to_buffer(p, buf, PLAIN_BUF_SIZE);

	if (ret)

		return;



	test(buf, fmt, p);

}



static void __init

symbol_ptr(void)

{
@@ -418,6 +449,29 @@ struct_va_format(void) 
{

}



static void __init

struct_rtc_time(void)

{

	/* 1543210543 */

	const struct rtc_time tm = {

		.tm_sec = 43,

		.tm_min = 35,

		.tm_hour = 5,

		.tm_mday = 26,

		.tm_mon = 10,

		.tm_year = 118,

	};



	test_hashed("%pt", &tm);



	test("2018-11-26T05:35:43", "%ptR", &tm);

	test("0118-10-26T05:35:43", "%ptRr", &tm);

	test("05:35:43|2018-11-26", "%ptRt|%ptRd", &tm, &tm);

	test("05:35:43|0118-10-26", "%ptRtr|%ptRdr", &tm, &tm);

	test("05:35:43|2018-11-26", "%ptRttr|%ptRdtr", &tm, &tm);

	test("05:35:43 tr|2018-11-26 tr", "%ptRt tr|%ptRd tr", &tm, &tm);

}



static void __init

struct_clk(void)

{
@@ -529,6 +583,7 @@ test_pointer(void) 
	uuid();

	dentry();

	struct_va_format();

	struct_rtc_time();

	struct_clk();

	bitmap();

	netdev_features();

lib/vsprintf.c

+100 −0
Original line number Diff line number Diff line
@@ -30,6 +30,7 @@ 
#include <linux/ioport.h>

#include <linux/dcache.h>

#include <linux/cred.h>

#include <linux/rtc.h>

#include <linux/uuid.h>

#include <linux/of.h>

#include <net/addrconf.h>
@@ -822,6 +823,20 @@ static const struct printf_spec default_dec_spec = { 
	.precision = -1,

};



static const struct printf_spec default_dec02_spec = {

	.base = 10,

	.field_width = 2,

	.precision = -1,

	.flags = ZEROPAD,

};



static const struct printf_spec default_dec04_spec = {

	.base = 10,

	.field_width = 4,

	.precision = -1,

	.flags = ZEROPAD,

};



static noinline_for_stack

char *resource_string(char *buf, char *end, struct resource *res,

		      struct printf_spec spec, const char *fmt)
@@ -1549,6 +1564,87 @@ char *address_val(char *buf, char *end, const void *addr, const char *fmt) 
	return special_hex_number(buf, end, num, size);

}



static noinline_for_stack

char *date_str(char *buf, char *end, const struct rtc_time *tm, bool r)

{

	int year = tm->tm_year + (r ? 0 : 1900);

	int mon = tm->tm_mon + (r ? 0 : 1);



	buf = number(buf, end, year, default_dec04_spec);

	if (buf < end)

		*buf = '-';

	buf++;



	buf = number(buf, end, mon, default_dec02_spec);

	if (buf < end)

		*buf = '-';

	buf++;



	return number(buf, end, tm->tm_mday, default_dec02_spec);

}



static noinline_for_stack

char *time_str(char *buf, char *end, const struct rtc_time *tm, bool r)

{

	buf = number(buf, end, tm->tm_hour, default_dec02_spec);

	if (buf < end)

		*buf = ':';

	buf++;



	buf = number(buf, end, tm->tm_min, default_dec02_spec);

	if (buf < end)

		*buf = ':';

	buf++;



	return number(buf, end, tm->tm_sec, default_dec02_spec);

}



static noinline_for_stack

char *rtc_str(char *buf, char *end, const struct rtc_time *tm, const char *fmt)

{

	bool have_t = true, have_d = true;

	bool raw = false;

	int count = 2;



	switch (fmt[count]) {

	case 'd':

		have_t = false;

		count++;

		break;

	case 't':

		have_d = false;

		count++;

		break;

	}



	raw = fmt[count] == 'r';



	if (have_d)

		buf = date_str(buf, end, tm, raw);

	if (have_d && have_t) {

		/* Respect ISO 8601 */

		if (buf < end)

			*buf = 'T';

		buf++;

	}

	if (have_t)

		buf = time_str(buf, end, tm, raw);



	return buf;

}



static noinline_for_stack

char *time_and_date(char *buf, char *end, void *ptr, struct printf_spec spec,

		    const char *fmt)

{

	switch (fmt[1]) {

	case 'R':

		return rtc_str(buf, end, (const struct rtc_time *)ptr, fmt);

	default:

		return ptr_to_id(buf, end, ptr, spec);

	}

}



static noinline_for_stack

char *clock(char *buf, char *end, struct clk *clk, struct printf_spec spec,

	    const char *fmt)
@@ -1828,6 +1924,8 @@ char *device_node_string(char *buf, char *end, struct device_node *dn, 
 * - 'd[234]' For a dentry name (optionally 2-4 last components)

 * - 'D[234]' Same as 'd' but for a struct file

 * - 'g' For block_device name (gendisk + partition number)

 * - 't[R][dt][r]' For time and date as represented:

 *      R    struct rtc_time

 * - 'C' For a clock, it prints the name (Common Clock Framework) or address

 *       (legacy clock framework) of the clock

 * - 'Cn' For a clock, it prints the name (Common Clock Framework) or address
@@ -1952,6 +2050,8 @@ char *pointer(const char *fmt, char *buf, char *end, void *ptr, 
		return address_val(buf, end, ptr, fmt);

	case 'd':

		return dentry_name(buf, end, ptr, spec, fmt);

	case 't':

		return time_and_date(buf, end, ptr, spec, fmt);

	case 'C':

		return clock(buf, end, ptr, spec, fmt);

	case 'D':

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