[U-Boot,v2] tiny-printf: Add support for %p format
diff mbox

Message ID 20170410065322.17131-1-vigneshr@ti.com
State Accepted
Commit cdce1f762029619e80061833b153cdbf3d0a0860
Delegated to: Tom Rini
Headers show

Commit Message

Vignesh Raghavendra April 10, 2017, 6:53 a.m. UTC
Add support for %p, %pa[p], %pM, %pm and %pI4 formats to tiny-printf.
%pM and %pI4 are widely used by SPL networking stack and is required if
networking support is desired in SPL.
%p, %pa and %pap are mostly used by debug prints and hence supported
only when DEBUG is enabled.

Before this patch:
$ size spl/u-boot-spl
   text	   data	    bss	    dec	    hex	filename
  99325	   4899	 218584	 322808	  4ecf8	spl/u-boot-spl

After this patch (with CONFIG_SPL_NET_SUPPORT):
$ size spl/u-boot-spl
   text	   data	    bss	    dec	    hex	filename
  99666	   4899	 218584	 323149	  4ee4d	spl/u-boot-spl

So, this patch adds ~350 bytes to code size.

If CONFIG_SPL_NET_SUPPORT is not enabled, this adds ~25 bytes.

If CONFIG_USE_TINY_PRINTF is disabled then:
$ size spl/u-boot-spl
  text	   data	    bss	    dec	    hex	filename
 101116	   4899	 218584	 324599	  4f3f7	spl/u-boot-spl

So, there is still ~1.4K space saved even with support for %pM/%pI4.

Compiler used is to build is:
arm-linux-gnueabihf-gcc (Linaro GCC 6.2-2016.11) 6.2.1 20161016

Signed-off-by: Vignesh R <vigneshr@ti.com>
---

Changes wrt RFC:
* support %p[ap] only under DEBUG
* Add comparsion data w/o tiny printf to commit message.

 lib/tiny-printf.c | 154 ++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 154 insertions(+)

Comments

Tom Rini April 11, 2017, 1:18 p.m. UTC | #1
On Mon, Apr 10, 2017 at 12:23:22PM +0530, Vignesh R wrote:

> Add support for %p, %pa[p], %pM, %pm and %pI4 formats to tiny-printf.
> %pM and %pI4 are widely used by SPL networking stack and is required if
> networking support is desired in SPL.
> %p, %pa and %pap are mostly used by debug prints and hence supported
> only when DEBUG is enabled.
> 
> Before this patch:
> $ size spl/u-boot-spl
>    text	   data	    bss	    dec	    hex	filename
>   99325	   4899	 218584	 322808	  4ecf8	spl/u-boot-spl
> 
> After this patch (with CONFIG_SPL_NET_SUPPORT):
> $ size spl/u-boot-spl
>    text	   data	    bss	    dec	    hex	filename
>   99666	   4899	 218584	 323149	  4ee4d	spl/u-boot-spl
> 
> So, this patch adds ~350 bytes to code size.
> 
> If CONFIG_SPL_NET_SUPPORT is not enabled, this adds ~25 bytes.
> 
> If CONFIG_USE_TINY_PRINTF is disabled then:
> $ size spl/u-boot-spl
>   text	   data	    bss	    dec	    hex	filename
>  101116	   4899	 218584	 324599	  4f3f7	spl/u-boot-spl
> 
> So, there is still ~1.4K space saved even with support for %pM/%pI4.
> 
> Compiler used is to build is:
> arm-linux-gnueabihf-gcc (Linaro GCC 6.2-2016.11) 6.2.1 20161016
> 
> Signed-off-by: Vignesh R <vigneshr@ti.com>

Reviewed-by: Tom Rini <trini@konsulko.com>
Simon Glass April 11, 2017, 1:56 p.m. UTC | #2
On 10 April 2017 at 00:53, Vignesh R <vigneshr@ti.com> wrote:
> Add support for %p, %pa[p], %pM, %pm and %pI4 formats to tiny-printf.
> %pM and %pI4 are widely used by SPL networking stack and is required if
> networking support is desired in SPL.
> %p, %pa and %pap are mostly used by debug prints and hence supported
> only when DEBUG is enabled.
>
> Before this patch:
> $ size spl/u-boot-spl
>    text    data     bss     dec     hex filename
>   99325    4899  218584  322808   4ecf8 spl/u-boot-spl
>
> After this patch (with CONFIG_SPL_NET_SUPPORT):
> $ size spl/u-boot-spl
>    text    data     bss     dec     hex filename
>   99666    4899  218584  323149   4ee4d spl/u-boot-spl
>
> So, this patch adds ~350 bytes to code size.
>
> If CONFIG_SPL_NET_SUPPORT is not enabled, this adds ~25 bytes.
>
> If CONFIG_USE_TINY_PRINTF is disabled then:
> $ size spl/u-boot-spl
>   text     data     bss     dec     hex filename
>  101116    4899  218584  324599   4f3f7 spl/u-boot-spl
>
> So, there is still ~1.4K space saved even with support for %pM/%pI4.
>
> Compiler used is to build is:
> arm-linux-gnueabihf-gcc (Linaro GCC 6.2-2016.11) 6.2.1 20161016
>
> Signed-off-by: Vignesh R <vigneshr@ti.com>
> ---
>
> Changes wrt RFC:
> * support %p[ap] only under DEBUG
> * Add comparsion data w/o tiny printf to commit message.
>
>  lib/tiny-printf.c | 154 ++++++++++++++++++++++++++++++++++++++++++++++++++++++
>  1 file changed, 154 insertions(+)
>
> diff --git a/lib/tiny-printf.c b/lib/tiny-printf.c
> index 6def8f98aa41..0b04813dc206 100644
> --- a/lib/tiny-printf.c
> +++ b/lib/tiny-printf.c
> @@ -12,6 +12,7 @@
>  #include <common.h>
>  #include <stdarg.h>
>  #include <serial.h>
> +#include <linux/ctype.h>
>
>  struct printf_info {
>         char *bf;       /* Digit buffer */
> @@ -52,6 +53,154 @@ static void div_out(struct printf_info *info, unsigned long *num,
>                 out_dgt(info, dgt);
>  }
>
> +#ifdef CONFIG_SPL_NET_SUPPORT
> +static void string(struct printf_info *info, char *s)
> +{
> +       char ch;
> +
> +       while ((ch = *s++))
> +               out(info, ch);
> +}
> +
> +static const char hex_asc[] = "0123456789abcdef";
> +#define hex_asc_lo(x)  hex_asc[((x) & 0x0f)]
> +#define hex_asc_hi(x)  hex_asc[((x) & 0xf0) >> 4]
> +
> +static inline char *pack_hex_byte(char *buf, u8 byte)
> +{
> +       *buf++ = hex_asc_hi(byte);
> +       *buf++ = hex_asc_lo(byte);
> +       return buf;
> +}
> +
> +static void mac_address_string(struct printf_info *info, u8 *addr,
> +                               bool separator)
> +{
> +       /* (6 * 2 hex digits), 5 colons and trailing zero */
> +       char mac_addr[6 * 3];
> +       char *p = mac_addr;
> +       int i;
> +
> +       for (i = 0; i < 6; i++) {
> +               p = pack_hex_byte(p, addr[i]);
> +               if (separator && i != 5)
> +                       *p++ = ':';
> +       }
> +       *p = '\0';
> +
> +       string(info, mac_addr);
> +}
> +
> +static char *put_dec_trunc(char *buf, unsigned int q)
> +{
> +       unsigned int d3, d2, d1, d0;
> +       d1 = (q >> 4) & 0xf;
> +       d2 = (q >> 8) & 0xf;
> +       d3 = (q >> 12);
> +
> +       d0 = 6 * (d3 + d2 + d1) + (q & 0xf);
> +       q = (d0 * 0xcd) >> 11;
> +       d0 = d0 - 10 * q;
> +       *buf++ = d0 + '0'; /* least significant digit */
> +       d1 = q + 9 * d3 + 5 * d2 + d1;
> +       if (d1 != 0) {
> +               q = (d1 * 0xcd) >> 11;
> +               d1 = d1 - 10 * q;
> +               *buf++ = d1 + '0'; /* next digit */
> +
> +               d2 = q + 2 * d2;
> +               if ((d2 != 0) || (d3 != 0)) {
> +                       q = (d2 * 0xd) >> 7;
> +                       d2 = d2 - 10 * q;
> +                       *buf++ = d2 + '0'; /* next digit */
> +
> +                       d3 = q + 4 * d3;
> +                       if (d3 != 0) {
> +                               q = (d3 * 0xcd) >> 11;
> +                               d3 = d3 - 10 * q;
> +                               *buf++ = d3 + '0';  /* next digit */
> +                               if (q != 0)
> +                                       *buf++ = q + '0'; /* most sign. digit */

OMG not the nicest code!

> +                       }
> +               }
> +       }
> +       return buf;
> +}
> +
> +static void ip4_addr_string(struct printf_info *info, u8 *addr)
> +{
> +       /* (4 * 3 decimal digits), 3 dots and trailing zero */
> +       char ip4_addr[4 * 4];
> +       char temp[3];   /* hold each IP quad in reverse order */
> +       char *p = ip4_addr;
> +       int i, digits;
> +
> +       for (i = 0; i < 4; i++) {
> +               digits = put_dec_trunc(temp, addr[i]) - temp;
> +               /* reverse the digits in the quad */
> +               while (digits--)
> +                       *p++ = temp[digits];
> +               if (i != 3)
> +                       *p++ = '.';
> +       }
> +       *p = '\0';
> +
> +       string(info, ip4_addr);
> +}
> +#endif
> +
> +/*
> + * Show a '%p' thing.  A kernel extension is that the '%p' is followed
> + * by an extra set of characters that are extended format
> + * specifiers.
> + *
> + * Right now we handle:
> + *
> + * - 'M' For a 6-byte MAC address, it prints the address in the
> + *       usual colon-separated hex notation.
> + * - 'm' Same as above except there is no colon-separator.
> + * - 'I4'for IPv4 addresses printed in the usual way (dot-separated
> + *       decimal).
> + */
> +
> +static void pointer(struct printf_info *info, const char *fmt, void *ptr)
> +{
> +#ifdef DEBUG

What is the #ifdef DEBUG for? It may not be enabled globally so I
don't think you can do this. You probably need this code always.

Having said that, at some point it would be nice to have a global
debug framework, which understood how to enable/disable debugging at
build-time or run-time.

Regards,
Simon
Tom Rini April 11, 2017, 2 p.m. UTC | #3
On Tue, Apr 11, 2017 at 07:56:06AM -0600, Simon Glass wrote:
> On 10 April 2017 at 00:53, Vignesh R <vigneshr@ti.com> wrote:
> > Add support for %p, %pa[p], %pM, %pm and %pI4 formats to tiny-printf.
> > %pM and %pI4 are widely used by SPL networking stack and is required if
> > networking support is desired in SPL.
> > %p, %pa and %pap are mostly used by debug prints and hence supported
> > only when DEBUG is enabled.
[snip]
> > +static void pointer(struct printf_info *info, const char *fmt, void *ptr)
> > +{
> > +#ifdef DEBUG
> 
> What is the #ifdef DEBUG for? It may not be enabled globally so I
> don't think you can do this. You probably need this code always.

So, %p/%pa/%pa[p] are used in debug() prints, which only matter when
DEBUG is set.  Doing it this way means we globally bloat by (I think I
snipped out..) 25 bytes? instead of ~250 bytes.  And since we're in
tiny-printf, which we use when every byte counts, I'm happier about only
bloating by 25 bytes here.
Simon Glass April 11, 2017, 2:03 p.m. UTC | #4
Hi Tom,

On 11 April 2017 at 08:00, Tom Rini <trini@konsulko.com> wrote:
> On Tue, Apr 11, 2017 at 07:56:06AM -0600, Simon Glass wrote:
>> On 10 April 2017 at 00:53, Vignesh R <vigneshr@ti.com> wrote:
>> > Add support for %p, %pa[p], %pM, %pm and %pI4 formats to tiny-printf.
>> > %pM and %pI4 are widely used by SPL networking stack and is required if
>> > networking support is desired in SPL.
>> > %p, %pa and %pap are mostly used by debug prints and hence supported
>> > only when DEBUG is enabled.
> [snip]
>> > +static void pointer(struct printf_info *info, const char *fmt, void *ptr)
>> > +{
>> > +#ifdef DEBUG
>>
>> What is the #ifdef DEBUG for? It may not be enabled globally so I
>> don't think you can do this. You probably need this code always.
>
> So, %p/%pa/%pa[p] are used in debug() prints, which only matter when
> DEBUG is set.  Doing it this way means we globally bloat by (I think I
> snipped out..) 25 bytes? instead of ~250 bytes.  And since we're in
> tiny-printf, which we use when every byte counts, I'm happier about only
> bloating by 25 bytes here.

What I mean is that typically DEBUG is enabled file by file. So if I
want to output something I need to enable DEBUG in this file as well?
That seems confusing to me. Perhaps it needs another CONFIG option?

Regards,
Simon
Tom Rini April 11, 2017, 2:13 p.m. UTC | #5
On Tue, Apr 11, 2017 at 08:03:07AM -0600, Simon Glass wrote:
> Hi Tom,
> 
> On 11 April 2017 at 08:00, Tom Rini <trini@konsulko.com> wrote:
> > On Tue, Apr 11, 2017 at 07:56:06AM -0600, Simon Glass wrote:
> >> On 10 April 2017 at 00:53, Vignesh R <vigneshr@ti.com> wrote:
> >> > Add support for %p, %pa[p], %pM, %pm and %pI4 formats to tiny-printf.
> >> > %pM and %pI4 are widely used by SPL networking stack and is required if
> >> > networking support is desired in SPL.
> >> > %p, %pa and %pap are mostly used by debug prints and hence supported
> >> > only when DEBUG is enabled.
> > [snip]
> >> > +static void pointer(struct printf_info *info, const char *fmt, void *ptr)
> >> > +{
> >> > +#ifdef DEBUG
> >>
> >> What is the #ifdef DEBUG for? It may not be enabled globally so I
> >> don't think you can do this. You probably need this code always.
> >
> > So, %p/%pa/%pa[p] are used in debug() prints, which only matter when
> > DEBUG is set.  Doing it this way means we globally bloat by (I think I
> > snipped out..) 25 bytes? instead of ~250 bytes.  And since we're in
> > tiny-printf, which we use when every byte counts, I'm happier about only
> > bloating by 25 bytes here.
> 
> What I mean is that typically DEBUG is enabled file by file. So if I
> want to output something I need to enable DEBUG in this file as well?
> That seems confusing to me. Perhaps it needs another CONFIG option?

I usually end up whacking DEBUG into common.h myself, so I hadn't
thought about it that way.  Long-term, yeah, we should think about how
to handle debug stuff as there's times you want everything on and times
you just want a little bit on, and we're talking about the we-need-space
case here too.
Simon Glass April 11, 2017, 2:28 p.m. UTC | #6
On 11 April 2017 at 08:13, Tom Rini <trini@konsulko.com> wrote:
> On Tue, Apr 11, 2017 at 08:03:07AM -0600, Simon Glass wrote:
>> Hi Tom,
>>
>> On 11 April 2017 at 08:00, Tom Rini <trini@konsulko.com> wrote:
>> > On Tue, Apr 11, 2017 at 07:56:06AM -0600, Simon Glass wrote:
>> >> On 10 April 2017 at 00:53, Vignesh R <vigneshr@ti.com> wrote:
>> >> > Add support for %p, %pa[p], %pM, %pm and %pI4 formats to tiny-printf.
>> >> > %pM and %pI4 are widely used by SPL networking stack and is required if
>> >> > networking support is desired in SPL.
>> >> > %p, %pa and %pap are mostly used by debug prints and hence supported
>> >> > only when DEBUG is enabled.
>> > [snip]
>> >> > +static void pointer(struct printf_info *info, const char *fmt, void *ptr)
>> >> > +{
>> >> > +#ifdef DEBUG
>> >>
>> >> What is the #ifdef DEBUG for? It may not be enabled globally so I
>> >> don't think you can do this. You probably need this code always.
>> >
>> > So, %p/%pa/%pa[p] are used in debug() prints, which only matter when
>> > DEBUG is set.  Doing it this way means we globally bloat by (I think I
>> > snipped out..) 25 bytes? instead of ~250 bytes.  And since we're in
>> > tiny-printf, which we use when every byte counts, I'm happier about only
>> > bloating by 25 bytes here.
>>
>> What I mean is that typically DEBUG is enabled file by file. So if I
>> want to output something I need to enable DEBUG in this file as well?
>> That seems confusing to me. Perhaps it needs another CONFIG option?
>
> I usually end up whacking DEBUG into common.h myself, so I hadn't
> thought about it that way.  Long-term, yeah, we should think about how
> to handle debug stuff as there's times you want everything on and times
> you just want a little bit on, and we're talking about the we-need-space
> case here too.

OK. Would be a nice little project for someone :-)

Reviewed-by: Simon Glass <sjg@chromium.org>
Tom Rini April 14, 2017, 9:10 p.m. UTC | #7
On Mon, Apr 10, 2017 at 12:23:22PM +0530, Vignesh R wrote:

> Add support for %p, %pa[p], %pM, %pm and %pI4 formats to tiny-printf.
> %pM and %pI4 are widely used by SPL networking stack and is required if
> networking support is desired in SPL.
> %p, %pa and %pap are mostly used by debug prints and hence supported
> only when DEBUG is enabled.
> 
> Before this patch:
> $ size spl/u-boot-spl
>    text	   data	    bss	    dec	    hex	filename
>   99325	   4899	 218584	 322808	  4ecf8	spl/u-boot-spl
> 
> After this patch (with CONFIG_SPL_NET_SUPPORT):
> $ size spl/u-boot-spl
>    text	   data	    bss	    dec	    hex	filename
>   99666	   4899	 218584	 323149	  4ee4d	spl/u-boot-spl
> 
> So, this patch adds ~350 bytes to code size.
> 
> If CONFIG_SPL_NET_SUPPORT is not enabled, this adds ~25 bytes.
> 
> If CONFIG_USE_TINY_PRINTF is disabled then:
> $ size spl/u-boot-spl
>   text	   data	    bss	    dec	    hex	filename
>  101116	   4899	 218584	 324599	  4f3f7	spl/u-boot-spl
> 
> So, there is still ~1.4K space saved even with support for %pM/%pI4.
> 
> Compiler used is to build is:
> arm-linux-gnueabihf-gcc (Linaro GCC 6.2-2016.11) 6.2.1 20161016
> 
> Signed-off-by: Vignesh R <vigneshr@ti.com>
> Reviewed-by: Tom Rini <trini@konsulko.com>
> Reviewed-by: Simon Glass <sjg@chromium.org>

Applied to u-boot/master, thanks!

Patch
diff mbox

diff --git a/lib/tiny-printf.c b/lib/tiny-printf.c
index 6def8f98aa41..0b04813dc206 100644
--- a/lib/tiny-printf.c
+++ b/lib/tiny-printf.c
@@ -12,6 +12,7 @@ 
 #include <common.h>
 #include <stdarg.h>
 #include <serial.h>
+#include <linux/ctype.h>
 
 struct printf_info {
 	char *bf;	/* Digit buffer */
@@ -52,6 +53,154 @@  static void div_out(struct printf_info *info, unsigned long *num,
 		out_dgt(info, dgt);
 }
 
+#ifdef CONFIG_SPL_NET_SUPPORT
+static void string(struct printf_info *info, char *s)
+{
+	char ch;
+
+	while ((ch = *s++))
+		out(info, ch);
+}
+
+static const char hex_asc[] = "0123456789abcdef";
+#define hex_asc_lo(x)	hex_asc[((x) & 0x0f)]
+#define hex_asc_hi(x)	hex_asc[((x) & 0xf0) >> 4]
+
+static inline char *pack_hex_byte(char *buf, u8 byte)
+{
+	*buf++ = hex_asc_hi(byte);
+	*buf++ = hex_asc_lo(byte);
+	return buf;
+}
+
+static void mac_address_string(struct printf_info *info, u8 *addr,
+				bool separator)
+{
+	/* (6 * 2 hex digits), 5 colons and trailing zero */
+	char mac_addr[6 * 3];
+	char *p = mac_addr;
+	int i;
+
+	for (i = 0; i < 6; i++) {
+		p = pack_hex_byte(p, addr[i]);
+		if (separator && i != 5)
+			*p++ = ':';
+	}
+	*p = '\0';
+
+	string(info, mac_addr);
+}
+
+static char *put_dec_trunc(char *buf, unsigned int q)
+{
+	unsigned int d3, d2, d1, d0;
+	d1 = (q >> 4) & 0xf;
+	d2 = (q >> 8) & 0xf;
+	d3 = (q >> 12);
+
+	d0 = 6 * (d3 + d2 + d1) + (q & 0xf);
+	q = (d0 * 0xcd) >> 11;
+	d0 = d0 - 10 * q;
+	*buf++ = d0 + '0'; /* least significant digit */
+	d1 = q + 9 * d3 + 5 * d2 + d1;
+	if (d1 != 0) {
+		q = (d1 * 0xcd) >> 11;
+		d1 = d1 - 10 * q;
+		*buf++ = d1 + '0'; /* next digit */
+
+		d2 = q + 2 * d2;
+		if ((d2 != 0) || (d3 != 0)) {
+			q = (d2 * 0xd) >> 7;
+			d2 = d2 - 10 * q;
+			*buf++ = d2 + '0'; /* next digit */
+
+			d3 = q + 4 * d3;
+			if (d3 != 0) {
+				q = (d3 * 0xcd) >> 11;
+				d3 = d3 - 10 * q;
+				*buf++ = d3 + '0';  /* next digit */
+				if (q != 0)
+					*buf++ = q + '0'; /* most sign. digit */
+			}
+		}
+	}
+	return buf;
+}
+
+static void ip4_addr_string(struct printf_info *info, u8 *addr)
+{
+	/* (4 * 3 decimal digits), 3 dots and trailing zero */
+	char ip4_addr[4 * 4];
+	char temp[3];	/* hold each IP quad in reverse order */
+	char *p = ip4_addr;
+	int i, digits;
+
+	for (i = 0; i < 4; i++) {
+		digits = put_dec_trunc(temp, addr[i]) - temp;
+		/* reverse the digits in the quad */
+		while (digits--)
+			*p++ = temp[digits];
+		if (i != 3)
+			*p++ = '.';
+	}
+	*p = '\0';
+
+	string(info, ip4_addr);
+}
+#endif
+
+/*
+ * Show a '%p' thing.  A kernel extension is that the '%p' is followed
+ * by an extra set of characters that are extended format
+ * specifiers.
+ *
+ * Right now we handle:
+ *
+ * - 'M' For a 6-byte MAC address, it prints the address in the
+ *       usual colon-separated hex notation.
+ * - 'm' Same as above except there is no colon-separator.
+ * - 'I4'for IPv4 addresses printed in the usual way (dot-separated
+ *       decimal).
+ */
+
+static void pointer(struct printf_info *info, const char *fmt, void *ptr)
+{
+#ifdef DEBUG
+	unsigned long num = (uintptr_t)ptr;
+	unsigned long div;
+#endif
+
+	switch (*fmt) {
+#ifdef DEBUG
+	case 'a':
+
+		switch (fmt[1]) {
+		case 'p':
+		default:
+			num = *(phys_addr_t *)ptr;
+			break;
+		}
+		break;
+#endif
+#ifdef CONFIG_SPL_NET_SUPPORT
+	case 'm':
+		return mac_address_string(info, ptr, false);
+	case 'M':
+		return mac_address_string(info, ptr, true);
+	case 'I':
+		if (fmt[1] == '4')
+			return ip4_addr_string(info, ptr);
+#endif
+	default:
+		break;
+	}
+#ifdef DEBUG
+	div = 1UL << (sizeof(long) * 8 - 4);
+	for (; div; div /= 0x10)
+		div_out(info, &num, div);
+#endif
+}
+
 static int _vprintf(struct printf_info *info, const char *fmt, va_list va)
 {
 	char ch;
@@ -144,6 +293,11 @@  static int _vprintf(struct printf_info *info, const char *fmt, va_list va)
 			case 's':
 				p = va_arg(va, char*);
 				break;
+			case 'p':
+				pointer(info, fmt, va_arg(va, void *));
+				while (isalnum(fmt[0]))
+					fmt++;
+				break;
 			case '%':
 				out(info, '%');
 			default: