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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: Jordan Crouse <jcrouse@codeaurora.org>
Signed-off-by: Rob Clark <robdclark@gmail.com>
hifive-unleashed-5.1
Jordan Crouse 2018-07-24 10:33:23 -06:00 committed by Rob Clark
parent 4538d73245
commit 5dc634bdbf
2 changed files with 56 additions and 40 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

94
drivers/gpu/drm/drm_print.c
View File

@ -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)
@ -65,43 +55,67 @@ 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 {
char *buf;
ssize_t pos = iterator->offset - iterator->start;
if (len < iterator->remain) {
snprintf(((char *) iterator->data) + pos,
iterator->remain, "%pV", vaf);
len = min_t(ssize_t, strlen(str), iterator->remain);
iterator->offset += len;
iterator->remain -= len;
memcpy(iterator->data + pos, str, 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 out the remaining bits */
memcpy(iterator->data + pos, buf, iterator->remain);
iterator->offset += iterator->remain;
iterator->remain = 0;
kfree(buf);
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;
snprintf(((char *) iterator->data) + pos,
iterator->remain, "%pV", vaf);
iterator->offset += len;
iterator->remain -= len;
return;
}
/*
* 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);
__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)

2
include/drm/drm_print.h
View File

@ -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,
};