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: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>

diff --git a/Documentation/core-api/printk-formats.rst b/Documentation/core-api/printk-formats.rst
index ff48b55040ef5acfd3ddac0cfca818f35116f472..a7fae4538946702ecadd09558a043dffb0ab60e3 100644 (file)
--- a/Documentation/core-api/printk-formats.rst
+++ b/Documentation/core-api/printk-formats.rst
@@ -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
 ----------
 

diff --git a/lib/test_printf.c b/lib/test_printf.c
index 53527ea822b53c0c35eb0025cd80cecde54403b3..659b6cc0d483e3018a3b511bb53d714ee116cbcb 100644 (file)
--- a/lib/test_printf.c
+++ b/lib/test_printf.c
@@ -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();

diff --git a/lib/vsprintf.c b/lib/vsprintf.c
index 37a54a6dd59481f0696d9c365cf0f1e06e762110..3add92329bae3d906200f9e09d1e916e97d14ae2 100644 (file)
--- a/lib/vsprintf.c
+++ b/lib/vsprintf.c
@@ -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':