[PATCH v1 0/5] fs/seq_file: introduce seq_hex_dump() helper

[PATCH v1 0/5] fs/seq_file: introduce seq_hex_dump() helper

[Andy Shevchenko]

This introduces a new helper and switches current users to use it.

parisc and s390 weren't tested anyhow, the other are compile tested.

Andy Shevchenko (5):
  seq_file: provide an analogue of print_hex_dump()
  saa7164: convert to seq_hex_dump()
  crypto: qat - use seq_hex_dump() to dump buffers
  parisc: use seq_hex_dump() to dump buffers
  [S390] zcrypt: use seq_hex_dump() to dump buffers

 .../crypto/qat/qat_common/adf_transport_debug.c    | 16 ++--------
 drivers/media/pci/saa7164/saa7164-core.c           | 31 +++----------------
 drivers/parisc/ccio-dma.c                          | 14 ++-------
 drivers/parisc/sba_iommu.c                         | 11 ++-----
 drivers/s390/crypto/zcrypt_api.c                   | 10 +------
 fs/seq_file.c                                      | 35 ++++++++++++++++++++++
 include/linux/seq_file.h                           |  4 +++
 7 files changed, 52 insertions(+), 69 deletions(-)

-- 
2.0.1

[PATCH v1 1/5] seq_file: provide an analogue of print_hex_dump()

[Andy Shevchenko]

The new seq_hex_dump() is a complete analogue of print_hex_dump().

We have few users of this functionality already. It allows to reduce their
codebase.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
---
 fs/seq_file.c            | 35 +++++++++++++++++++++++++++++++++++
 include/linux/seq_file.h |  4 ++++
 2 files changed, 39 insertions(+)

diff --git a/fs/seq_file.c b/fs/seq_file.c
index 3857b72..fec4a6b 100644
--- a/fs/seq_file.c
+++ b/fs/seq_file.c
@@ -12,6 +12,7 @@
 #include <linux/slab.h>
 #include <linux/cred.h>
 #include <linux/mm.h>
+#include <linux/printk.h>
 
 #include <asm/uaccess.h>
 #include <asm/page.h>
@@ -794,6 +795,40 @@ void seq_pad(struct seq_file *m, char c)
 }
 EXPORT_SYMBOL(seq_pad);
 
+/* Analogue of print_hex_dump() */
+void seq_hex_dump(struct seq_file *m, const char *prefix_str, int prefix_type,
+		  int rowsize, int groupsize, const void *buf, size_t len,
+		  bool ascii)
+{
+	const u8 *ptr = buf;
+	int i, linelen, remaining = len;
+	unsigned char linebuf[32 * 3 + 2 + 32 + 1];
+
+	if (rowsize != 16 && rowsize != 32)
+		rowsize = 16;
+
+	for (i = 0; i < len; i += rowsize) {
+		linelen = min(remaining, rowsize);
+		remaining -= rowsize;
+
+		hex_dump_to_buffer(ptr + i, linelen, rowsize, groupsize,
+				   linebuf, sizeof(linebuf), ascii);
+
+		switch (prefix_type) {
+		case DUMP_PREFIX_ADDRESS:
+			seq_printf(m, "%s%p: %s\n", prefix_str, ptr + i, linebuf);
+			break;
+		case DUMP_PREFIX_OFFSET:
+			seq_printf(m, "%s%.8x: %s\n", prefix_str, i, linebuf);
+			break;
+		default:
+			seq_printf(m, "%s%s\n", prefix_str, linebuf);
+			break;
+		}
+	}
+}
+EXPORT_SYMBOL(seq_hex_dump);
+
 struct list_head *seq_list_start(struct list_head *head, loff_t pos)
 {
 	struct list_head *lh;
diff --git a/include/linux/seq_file.h b/include/linux/seq_file.h
index 52e0097..6a8be4c 100644
--- a/include/linux/seq_file.h
+++ b/include/linux/seq_file.h
@@ -107,6 +107,10 @@ int seq_write(struct seq_file *seq, const void *data, size_t len);
 __printf(2, 3) int seq_printf(struct seq_file *, const char *, ...);
 __printf(2, 0) int seq_vprintf(struct seq_file *, const char *, va_list args);
 
+void seq_hex_dump(struct seq_file *m, const char *prefix_str, int prefix_type,
+		  int rowsize, int groupsize, const void *buf, size_t len,
+		  bool ascii);
+
 int seq_path(struct seq_file *, const struct path *, const char *);
 int seq_dentry(struct seq_file *, struct dentry *, const char *);
 int seq_path_root(struct seq_file *m, const struct path *path,
-- 
2.0.1

Re: [PATCH v1 1/5] seq_file: provide an analogue of print_hex_dump()

[Marek Vasut]

On Wednesday, July 09, 2014 at 05:24:26 PM, Andy Shevchenko wrote:
> The new seq_hex_dump() is a complete analogue of print_hex_dump().
> 
> We have few users of this functionality already. It allows to reduce their
> codebase.
> 
> Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
> ---
>  fs/seq_file.c            | 35 +++++++++++++++++++++++++++++++++++
>  include/linux/seq_file.h |  4 ++++
>  2 files changed, 39 insertions(+)
> 
> diff --git a/fs/seq_file.c b/fs/seq_file.c
> index 3857b72..fec4a6b 100644
> --- a/fs/seq_file.c
> +++ b/fs/seq_file.c
> @@ -12,6 +12,7 @@
>  #include <linux/slab.h>
>  #include <linux/cred.h>
>  #include <linux/mm.h>
> +#include <linux/printk.h>
> 
>  #include <asm/uaccess.h>
>  #include <asm/page.h>
> @@ -794,6 +795,40 @@ void seq_pad(struct seq_file *m, char c)
>  }
>  EXPORT_SYMBOL(seq_pad);
> 
> +/* Analogue of print_hex_dump() */
> +void seq_hex_dump(struct seq_file *m, const char *prefix_str, int
> prefix_type, +		  int rowsize, int groupsize, const void *buf, 
size_t len,
> +		  bool ascii)
> +{
> +	const u8 *ptr = buf;
> +	int i, linelen, remaining = len;
> +	unsigned char linebuf[32 * 3 + 2 + 32 + 1];
> +
> +	if (rowsize != 16 && rowsize != 32)
> +		rowsize = 16;
> +
> +	for (i = 0; i < len; i += rowsize) {
> +		linelen = min(remaining, rowsize);
> +		remaining -= rowsize;
> +
> +		hex_dump_to_buffer(ptr + i, linelen, rowsize, groupsize,
> +				   linebuf, sizeof(linebuf), ascii);
> +
> +		switch (prefix_type) {
> +		case DUMP_PREFIX_ADDRESS:
> +			seq_printf(m, "%s%p: %s\n", prefix_str, ptr + i, 
linebuf);
> +			break;
> +		case DUMP_PREFIX_OFFSET:
> +			seq_printf(m, "%s%.8x: %s\n", prefix_str, i, linebuf);
> +			break;
> +		default:
> +			seq_printf(m, "%s%s\n", prefix_str, linebuf);
> +			break;
> +		}
> +	}
> +}
> +EXPORT_SYMBOL(seq_hex_dump);

The above function looks like almost verbatim copy of print_hex_dump(). The only 
difference I can spot is that it's calling seq_printf() instead of printk(). Can 
you not instead generalize print_hex_dump() and based on it's invocation, make 
it call either seq_printf() or printk() ?

Best regards,

Re: [PATCH v1 1/5] seq_file: provide an analogue of print_hex_dump()

[Joe Perches]

On Wed, 2014-07-09 at 22:39 +0200, Marek Vasut wrote:
> The above function looks like almost verbatim copy of print_hex_dump(). The only 
> difference I can spot is that it's calling seq_printf() instead of printk(). Can 
> you not instead generalize print_hex_dump() and based on it's invocation, make 
> it call either seq_printf() or printk() ?

How do you propose doing that given any seq_<foo> call
requires a struct seq_file * and print_hex_dump needs
a KERN_<LEVEL>.

Is there an actual value to it?

Re: [PATCH v1 1/5] seq_file: provide an analogue of print_hex_dump()

[Marek Vasut]

On Wednesday, July 09, 2014 at 11:21:08 PM, Joe Perches wrote:
> On Wed, 2014-07-09 at 22:39 +0200, Marek Vasut wrote:
> > The above function looks like almost verbatim copy of print_hex_dump().
> > The only difference I can spot is that it's calling seq_printf() instead
> > of printk(). Can you not instead generalize print_hex_dump() and based
> > on it's invocation, make it call either seq_printf() or printk() ?
> 
> How do you propose doing that given any seq_<foo> call
> requires a struct seq_file * and print_hex_dump needs
> a KERN_<LEVEL>.

I can imagine a rather nasty way, I can't say I would like it myself tho. The 
general idea would be to pull out the entire switch {} statement into a separate 
functions , one for printk() and one for seq_printf() cases. Then, have a 
generic do_hex_dump() call which would take as an argument a pointer to either 
of those functions and a void * to either the seq_file or level . Finally, there 
would have to be a wrapper to call the do_hex_dump() with the correct function 
pointer and it's associated arg.

Nasty? Yes ... Ineffective? Most likely.

> Is there an actual value to it?

Reducing the code duplication, but I wonder if there is a smarter solution than 
the horrid one above.

Best regards,
Marek Vasut

Re: [PATCH v1 1/5] seq_file: provide an analogue of print_hex_dump()

[Andy Shevchenko]

On Thu, 2014-07-10 at 09:58 +0200, Marek Vasut wrote:
> On Wednesday, July 09, 2014 at 11:21:08 PM, Joe Perches wrote:
> > On Wed, 2014-07-09 at 22:39 +0200, Marek Vasut wrote:
> > > The above function looks like almost verbatim copy of print_hex_dump().
> > > The only difference I can spot is that it's calling seq_printf() instead
> > > of printk(). Can you not instead generalize print_hex_dump() and based
> > > on it's invocation, make it call either seq_printf() or printk() ?
> > 
> > How do you propose doing that given any seq_<foo> call
> > requires a struct seq_file * and print_hex_dump needs
> > a KERN_<LEVEL>.
> 
> I can imagine a rather nasty way, I can't say I would like it myself tho. The 
> general idea would be to pull out the entire switch {} statement into a separate 
> functions , one for printk() and one for seq_printf() cases. Then, have a 
> generic do_hex_dump() call which would take as an argument a pointer to either 
> of those functions and a void * to either the seq_file or level . Finally, there 
> would have to be a wrapper to call the do_hex_dump() with the correct function 
> pointer and it's associated arg.
> 
> Nasty? Yes ... Ineffective? Most likely.

It looks not good idea, yeah.

> > Is there an actual value to it?
> 
> Reducing the code duplication, but I wonder if there is a smarter solution than 
> the horrid one above.

I have considered to modify hex_dump_to_buffer() to return how many
bytes it actually proceed to the buffer. In that case we can directly
print to m->buf like other seq_<foo> calls do.

But I still have doubts about it. Any opinion?

-- 
Andy Shevchenko <andriy.shevchenko@intel.com>
Intel Finland Oy

Re: [PATCH v1 1/5] seq_file: provide an analogue of print_hex_dump()

[Joe Perches]

On Thu, 2014-07-10 at 12:50 +0300, Andy Shevchenko wrote:
> I have considered to modify hex_dump_to_buffer() to return how many
> bytes it actually proceed to the buffer. In that case we can directly
> print to m->buf like other seq_<foo> calls do.
> 
> But I still have doubts about it. Any opinion?

Simpler is better.

[PATCH v1 2/5] saa7164: convert to seq_hex_dump()

[Andy Shevchenko]

Instead of custom approach let's use recently added seq_hex_dump() helper.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
---
 drivers/media/pci/saa7164/saa7164-core.c | 31 ++++---------------------------
 1 file changed, 4 insertions(+), 27 deletions(-)

diff --git a/drivers/media/pci/saa7164/saa7164-core.c b/drivers/media/pci/saa7164/saa7164-core.c
index 1bf0697..6f81584 100644
--- a/drivers/media/pci/saa7164/saa7164-core.c
+++ b/drivers/media/pci/saa7164/saa7164-core.c
@@ -1065,7 +1065,6 @@ static int saa7164_proc_show(struct seq_file *m, void *v)
 	struct saa7164_dev *dev;
 	struct tmComResBusInfo *b;
 	struct list_head *list;
-	int i, c;
 
 	if (saa7164_devcount == 0)
 		return 0;
@@ -1089,35 +1088,13 @@ static int saa7164_proc_show(struct seq_file *m, void *v)
 
 		seq_printf(m, " .m_pdwGetReadPos  = 0x%x (0x%08x)\n",
 			b->m_dwGetWritePos, saa7164_readl(b->m_dwGetWritePos));
-		c = 0;
 		seq_printf(m, "\n  Set Ring:\n");
-		seq_printf(m, "\n addr  00 01 02 03 04 05 06 07 08 09 0a 0b 0c 0d 0e 0f\n");
-		for (i = 0; i < b->m_dwSizeSetRing; i++) {
-			if (c == 0)
-				seq_printf(m, " %04x:", i);
+		seq_hex_dump(m, " ", DUMP_PREFIX_OFFSET, 16, 1,
+			     b->m_pdwSetRing, b->m_dwSizeSetRing, false);
 
-			seq_printf(m, " %02x", *(b->m_pdwSetRing + i));
-
-			if (++c == 16) {
-				seq_printf(m, "\n");
-				c = 0;
-			}
-		}
-
-		c = 0;
 		seq_printf(m, "\n  Get Ring:\n");
-		seq_printf(m, "\n addr  00 01 02 03 04 05 06 07 08 09 0a 0b 0c 0d 0e 0f\n");
-		for (i = 0; i < b->m_dwSizeGetRing; i++) {
-			if (c == 0)
-				seq_printf(m, " %04x:", i);
-
-			seq_printf(m, " %02x", *(b->m_pdwGetRing + i));
-
-			if (++c == 16) {
-				seq_printf(m, "\n");
-				c = 0;
-			}
-		}
+		seq_hex_dump(m, " ", DUMP_PREFIX_OFFSET, 16, 1,
+			     b->m_pdwGetRing, b->m_dwSizeGetRing, false);
 
 		mutex_unlock(&b->lock);
 
-- 
2.0.1

Re: [PATCH v1 2/5] saa7164: convert to seq_hex_dump()

[Steven Toth]

On Wed, Jul 9, 2014 at 11:24 AM, Andy Shevchenko
<andriy.shevchenko@linux.intel.com> wrote:
> Instead of custom approach let's use recently added seq_hex_dump() helper.
>
> Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>

ack

Reviewed-by: Steven Toth <stoth@kernellabs.com>

-- 
Steven Toth - Kernel Labs
http://www.kernellabs.com

Re: [PATCH v1 2/5] saa7164: convert to seq_hex_dump()

[Mauro Carvalho Chehab]

Em Wed, 9 Jul 2014 14:24:29 -0400
Steven Toth <stoth@kernellabs.com> escreveu:

> On Wed, Jul 9, 2014 at 11:24 AM, Andy Shevchenko
> <andriy.shevchenko@linux.intel.com> wrote:
> > Instead of custom approach let's use recently added seq_hex_dump() helper.
> >
> > Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
> 
> ack
> 
> Reviewed-by: Steven Toth <stoth@kernellabs.com>
> 
Acked-by: Mauro Carvalho Chehab <m.chehab@samsung.com>

Regards,
Mauro

[PATCH v1 3/5] crypto: qat - use seq_hex_dump() to dump buffers

[Andy Shevchenko]

Instead of custom approach let's use recently introduced seq_hex_dump() helper.

In this case it slightly changes the output, namely the four tetrads will be
output on one line.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
---
 drivers/crypto/qat/qat_common/adf_transport_debug.c | 16 ++--------------
 1 file changed, 2 insertions(+), 14 deletions(-)

diff --git a/drivers/crypto/qat/qat_common/adf_transport_debug.c b/drivers/crypto/qat/qat_common/adf_transport_debug.c
index 6b69745..8b103cf 100644
--- a/drivers/crypto/qat/qat_common/adf_transport_debug.c
+++ b/drivers/crypto/qat/qat_common/adf_transport_debug.c
@@ -86,9 +86,7 @@ static int adf_ring_show(struct seq_file *sfile, void *v)
 {
 	struct adf_etr_ring_data *ring = sfile->private;
 	struct adf_etr_bank_data *bank = ring->bank;
-	uint32_t *msg = v;
 	void __iomem *csr = ring->bank->csr_addr;
-	int i, x;
 
 	if (v == SEQ_START_TOKEN) {
 		int head, tail, empty;
@@ -111,18 +109,8 @@ static int adf_ring_show(struct seq_file *sfile, void *v)
 		seq_puts(sfile, "----------- Ring data ------------\n");
 		return 0;
 	}
-	seq_printf(sfile, "%p:", msg);
-	x = 0;
-	i = 0;
-	for (; i < (ADF_MSG_SIZE_TO_BYTES(ring->msg_size) >> 2); i++) {
-		seq_printf(sfile, " %08X", *(msg + i));
-		if ((ADF_MSG_SIZE_TO_BYTES(ring->msg_size) >> 2) != i + 1 &&
-		    (++x == 8)) {
-			seq_printf(sfile, "\n%p:", msg + i + 1);
-			x = 0;
-		}
-	}
-	seq_puts(sfile, "\n");
+	seq_hex_dump(sfile, "", DUMP_PREFIX_ADDRESS, 16, 4,
+		     v, ADF_MSG_SIZE_TO_BYTES(ring->msg_size), false);
 	return 0;
 }
 
-- 
2.0.1

Re: [PATCH v1 3/5] crypto: qat - use seq_hex_dump() to dump buffers

[Andy Shevchenko]

On Wed, 2014-07-09 at 11:31 -0700, Tadeusz Struk wrote:
> On 07/09/2014 08:24 AM, Andy Shevchenko wrote:
> 
> > In this case it slightly changes the output, namely the four tetrads will be
> > output on one line.
> > 
> > Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
> 
> It's ok, I can still read it.

It seems I miscalculated the tetrads. It should be 8 per line, correct?
In that case we could easily use 32 bytes per line and thus remove that
paragraph from commit message.

> Acked-by: Tadeusz Struk <tadeusz.struk@intel.com>

Thanks!


-- 
Andy Shevchenko <andriy.shevchenko@intel.com>
Intel Finland Oy

[PATCH v1 4/5] parisc: use seq_hex_dump() to dump buffers

[Andy Shevchenko]

Instead of custom approach let's use recently introduced seq_hex_dump() helper.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
---
 drivers/parisc/ccio-dma.c  | 14 +++-----------
 drivers/parisc/sba_iommu.c | 11 +++--------
 2 files changed, 6 insertions(+), 19 deletions(-)

diff --git a/drivers/parisc/ccio-dma.c b/drivers/parisc/ccio-dma.c
index 8b490d7..9d353d2 100644
--- a/drivers/parisc/ccio-dma.c
+++ b/drivers/parisc/ccio-dma.c
@@ -1101,20 +1101,12 @@ static const struct file_operations ccio_proc_info_fops = {
 
 static int ccio_proc_bitmap_info(struct seq_file *m, void *p)
 {
-	int len = 0;
 	struct ioc *ioc = ioc_list;
 
 	while (ioc != NULL) {
-		u32 *res_ptr = (u32 *)ioc->res_map;
-		int j;
-
-		for (j = 0; j < (ioc->res_size / sizeof(u32)); j++) {
-			if ((j & 7) == 0)
-				len += seq_puts(m, "\n   ");
-			len += seq_printf(m, "%08x", *res_ptr);
-			res_ptr++;
-		}
-		len += seq_puts(m, "\n\n");
+		seq_hex_dump(m, "   ", DUMP_PREFIX_NONE, 32, 4, ioc->res_map,
+			     ioc->res_size, false);
+		seq_putc(m, '\n');
 		ioc = ioc->next;
 		break; /* XXX - remove me */
 	}
diff --git a/drivers/parisc/sba_iommu.c b/drivers/parisc/sba_iommu.c
index 1ff1b67..fbc4db9 100644
--- a/drivers/parisc/sba_iommu.c
+++ b/drivers/parisc/sba_iommu.c
@@ -1857,15 +1857,10 @@ sba_proc_bitmap_info(struct seq_file *m, void *p)
 {
 	struct sba_device *sba_dev = sba_list;
 	struct ioc *ioc = &sba_dev->ioc[0];	/* FIXME: Multi-IOC support! */
-	unsigned int *res_ptr = (unsigned int *)ioc->res_map;
-	int i, len = 0;
 
-	for (i = 0; i < (ioc->res_size/sizeof(unsigned int)); ++i, ++res_ptr) {
-		if ((i & 7) == 0)
-			len += seq_printf(m, "\n   ");
-		len += seq_printf(m, " %08x", *res_ptr);
-	}
-	len += seq_printf(m, "\n");
+	seq_hex_dump(m, "   ", DUMP_PREFIX_NONE, 32, 4, ioc->res_map,
+		     ioc->res_size, false);
+	seq_printf(m, "\n");
 
 	return 0;
 }
-- 
2.0.1

Re: [PATCH v1 4/5] parisc: use seq_hex_dump() to dump buffers

[Joe Perches]

On Wed, 2014-07-09 at 18:24 +0300, Andy Shevchenko wrote:
> Instead of custom approach let's use recently introduced seq_hex_dump() helper.

Doesn't this also change the output from
   1111111122222222333333334444444455555555666666667777777788888888
to
   11111111 22222222 33333333 44444444 55555555 66666666 77777777 88888888

Re: [PATCH v1 4/5] parisc: use seq_hex_dump() to dump buffers

[Andy Shevchenko]

In one case indeed it does, in another - no, though it seems it prints
same data (by meaning) in both cases. I would like driver maintainer
to say a word what they think about it.

On Wed, Jul 9, 2014 at 9:26 PM, Joe Perches <joe@perches.com> wrote:
> On Wed, 2014-07-09 at 18:24 +0300, Andy Shevchenko wrote:
>> Instead of custom approach let's use recently introduced seq_hex_dump() helper.
>
> Doesn't this also change the output from
>    1111111122222222333333334444444455555555666666667777777788888888
> to
>    11111111 22222222 33333333 44444444 55555555 66666666 77777777 88888888
>
>
> --
> To unsubscribe from this list: send the line "unsubscribe linux-media" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html



-- 
With Best Regards,
Andy Shevchenko

[PATCH v1 5/5] [S390] zcrypt: use seq_hex_dump() to dump buffers

[Andy Shevchenko]

Instead of custom approach let's use recently introduced seq_hex_dump() helper.

In this case it slightly changes the output, namely the four tetrads will be
output on one line.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
---
 drivers/s390/crypto/zcrypt_api.c | 10 +---------
 1 file changed, 1 insertion(+), 9 deletions(-)

diff --git a/drivers/s390/crypto/zcrypt_api.c b/drivers/s390/crypto/zcrypt_api.c
index 0e18c5d..d1f9983 100644
--- a/drivers/s390/crypto/zcrypt_api.c
+++ b/drivers/s390/crypto/zcrypt_api.c
@@ -1203,16 +1203,8 @@ static void sprinthx(unsigned char *title, struct seq_file *m,
 static void sprinthx4(unsigned char *title, struct seq_file *m,
 		      unsigned int *array, unsigned int len)
 {
-	int r;
-
 	seq_printf(m, "\n%s\n", title);
-	for (r = 0; r < len; r++) {
-		if ((r % 8) == 0)
-			seq_printf(m, "    ");
-		seq_printf(m, "%08X ", array[r]);
-		if ((r % 8) == 7)
-			seq_putc(m, '\n');
-	}
+	seq_hex_dump(m, "    ", DUMP_PREFIX_NONE, 32, 4, array, len, false);
 	seq_putc(m, '\n');
 }
 
-- 
2.0.1

Re: [PATCH v1 5/5] [S390] zcrypt: use seq_hex_dump() to dump buffers

[Andy Shevchenko]

On Wed, 2014-07-09 at 18:24 +0300, Andy Shevchenko wrote:
> Instead of custom approach let's use recently introduced seq_hex_dump() helper.
> 
> In this case it slightly changes the output, namely the four tetrads will be
> output on one line.

The above paragraph is not true and will be removed in v2.
The output is kept the same as in original code.

> 
> Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
> ---
>  drivers/s390/crypto/zcrypt_api.c | 10 +---------
>  1 file changed, 1 insertion(+), 9 deletions(-)
> 
> diff --git a/drivers/s390/crypto/zcrypt_api.c b/drivers/s390/crypto/zcrypt_api.c
> index 0e18c5d..d1f9983 100644
> --- a/drivers/s390/crypto/zcrypt_api.c
> +++ b/drivers/s390/crypto/zcrypt_api.c
> @@ -1203,16 +1203,8 @@ static void sprinthx(unsigned char *title, struct seq_file *m,
>  static void sprinthx4(unsigned char *title, struct seq_file *m,
>  		      unsigned int *array, unsigned int len)
>  {
> -	int r;
> -
>  	seq_printf(m, "\n%s\n", title);
> -	for (r = 0; r < len; r++) {
> -		if ((r % 8) == 0)
> -			seq_printf(m, "    ");
> -		seq_printf(m, "%08X ", array[r]);
> -		if ((r % 8) == 7)
> -			seq_putc(m, '\n');
> -	}
> +	seq_hex_dump(m, "    ", DUMP_PREFIX_NONE, 32, 4, array, len, false);
>  	seq_putc(m, '\n');
>  }
>  


-- 
Andy Shevchenko <andriy.shevchenko@intel.com>
Intel Finland Oy

Re: [PATCH v1 0/5] fs/seq_file: introduce seq_hex_dump() helper

[Joe Perches]

On Wed, 2014-07-09 at 18:24 +0300, Andy Shevchenko wrote:
> This introduces a new helper and switches current users to use it.

While seq_print_hex_dump seems useful, I'm not sure
existing forms can be changed to use it if any output
content changes.

seq_ is supposed to be a stable API.