Commit 5dc634bd authored by Jordan Crouse's avatar Jordan Crouse Committed by Rob Clark
Browse files

drm: Add puts callback for the coredump printer 



Add a puts function for the coredump printer to bypass printf()
for constant strings for a speed boost. Reorganize the
coredump printf callback to share as much code as possible.

v2: Try to reuse code between print and puts as suggested by
    Chris Wilson

Signed-off-by: default avatarJordan Crouse <jcrouse@codeaurora.org>
Signed-off-by: default avatarRob Clark <robdclark@gmail.com>
parent 4538d732

drivers/gpu/drm/drm_print.c

+49 −35
Original line number Diff line number Diff line
@@ -30,7 +30,7 @@ 
#include <drm/drmP.h>

#include <drm/drm_print.h>



void __drm_printfn_coredump(struct drm_printer *p, struct va_format *vaf)

void __drm_puts_coredump(struct drm_printer *p, const char *str)

{

	struct drm_print_iterator *iterator = p->arg;

	ssize_t len;
@@ -38,26 +38,16 @@ void __drm_printfn_coredump(struct drm_printer *p, struct va_format *vaf) 
	if (!iterator->remain)

		return;



	/* Figure out how big the string will be */

	len = snprintf(NULL, 0, "%pV", vaf);



	if (iterator->offset < iterator->start) {

		char *buf;

		ssize_t copy;



		len = strlen(str);



		if (iterator->offset + len <= iterator->start) {

			iterator->offset += len;

			return;

		}



		/* Print the string into a temporary buffer */

		buf = kmalloc(len + 1,

			GFP_KERNEL | __GFP_NOWARN | __GFP_NORETRY);

		if (!buf)

			return;



		snprintf(buf, len + 1, "%pV", vaf);



		copy = len - (iterator->start - iterator->offset);



		if (copy > iterator->remain)
@@ -65,17 +55,45 @@ void __drm_printfn_coredump(struct drm_printer *p, struct va_format *vaf) 


		/* Copy out the bit of the string that we need */

		memcpy(iterator->data,

			buf + (iterator->start - iterator->offset), copy);

			str + (iterator->start - iterator->offset), copy);



		iterator->offset = iterator->start + copy;

		iterator->remain -= copy;



		kfree(buf);

	} else {

		ssize_t pos = iterator->offset - iterator->start;



		len = min_t(ssize_t, strlen(str), iterator->remain);



		memcpy(iterator->data + pos, str, len);



		iterator->offset += len;

		iterator->remain -= len;

	}

}

EXPORT_SYMBOL(__drm_puts_coredump);



void __drm_printfn_coredump(struct drm_printer *p, struct va_format *vaf)

{

	struct drm_print_iterator *iterator = p->arg;

	size_t len;

	char *buf;



	if (!iterator->remain)

		return;



	/* Figure out how big the string will be */

	len = snprintf(NULL, 0, "%pV", vaf);



	/* This is the easiest path, we've already advanced beyond the offset */

	if (iterator->offset + len <= iterator->start) {

		iterator->offset += len;

		return;

	}



	/* Then check if we can directly copy into the target buffer */

	if ((iterator->offset >= iterator->start) && (len < iterator->remain)) {

		ssize_t pos = iterator->offset - iterator->start;



		if (len < iterator->remain) {

		snprintf(((char *) iterator->data) + pos,

			iterator->remain, "%pV", vaf);
@@ -85,23 +103,19 @@ void __drm_printfn_coredump(struct drm_printer *p, struct va_format *vaf) 
		return;

	}



		/* Print the string into a temporary buffer */

		buf = kmalloc(len + 1,

			GFP_KERNEL | __GFP_NOWARN | __GFP_NORETRY);

	/*

	 * Finally, hit the slow path and make a temporary string to copy over

	 * using _drm_puts_coredump

	 */

	buf = kmalloc(len + 1, GFP_KERNEL | __GFP_NOWARN | __GFP_NORETRY);

	if (!buf)

		return;



	snprintf(buf, len + 1, "%pV", vaf);



		/* Copy out the remaining bits */

		memcpy(iterator->data + pos, buf, iterator->remain);



		iterator->offset += iterator->remain;

		iterator->remain = 0;

	__drm_puts_coredump(p, (const char *) buf);



	kfree(buf);

}

}

EXPORT_SYMBOL(__drm_printfn_coredump);



void __drm_puts_seq_file(struct drm_printer *p, const char *str)

include/drm/drm_print.h

+2 −0
Original line number Diff line number Diff line
@@ -75,6 +75,7 @@ struct drm_printer { 
};



void __drm_printfn_coredump(struct drm_printer *p, struct va_format *vaf);

void __drm_puts_coredump(struct drm_printer *p, const char *str);

void __drm_printfn_seq_file(struct drm_printer *p, struct va_format *vaf);

void __drm_puts_seq_file(struct drm_printer *p, const char *str);

void __drm_printfn_info(struct drm_printer *p, struct va_format *vaf);
@@ -163,6 +164,7 @@ drm_coredump_printer(struct drm_print_iterator *iter) 
{

	struct drm_printer p = {

		.printfn = __drm_printfn_coredump,

		.puts = __drm_puts_coredump,

		.arg = iter,

	};

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