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authorJordan Crouse <jcrouse@codeaurora.org>2018-07-24 19:33:23 +0300
committerRob Clark <robdclark@gmail.com>2018-07-30 15:49:41 +0300
commit5dc634bdbfd6dd9bdf98bce0d6f64878e1d47b1f (patch)
treefe3b6b07dcc1c70ad53b27c10f53e0ea9d52732b /drivers/gpu/drm/drm_print.c
parent4538d7324507fed892a18b79ad72c8501b6e7027 (diff)
downloadlinux-5dc634bdbfd6dd9bdf98bce0d6f64878e1d47b1f.tar.xz
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>
Diffstat (limited to 'drivers/gpu/drm/drm_print.c')
-rw-r--r--drivers/gpu/drm/drm_print.c84
1 files changed, 49 insertions, 35 deletions
diff --git a/drivers/gpu/drm/drm_print.c b/drivers/gpu/drm/drm_print.c
index 45d787611723..0e7fc3e7dfb4 100644
--- a/drivers/gpu/drm/drm_print.c
+++ b/drivers/gpu/drm/drm_print.c
@@ -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)
@@ -65,42 +55,66 @@ 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;
- }
+ iterator->offset += len;
+ iterator->remain -= len;
+ }
+}
+EXPORT_SYMBOL(__drm_puts_coredump);
- /* Print the string into a temporary buffer */
- buf = kmalloc(len + 1,
- GFP_KERNEL | __GFP_NOWARN | __GFP_NORETRY);
- if (!buf)
- return;
+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;
+ }
- snprintf(buf, len + 1, "%pV", vaf);
+ /* 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;
- /* Copy out the remaining bits */
- memcpy(iterator->data + pos, buf, iterator->remain);
+ snprintf(((char *) iterator->data) + pos,
+ iterator->remain, "%pV", vaf);
- iterator->offset += iterator->remain;
- iterator->remain = 0;
+ iterator->offset += len;
+ iterator->remain -= len;
- kfree(buf);
+ 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);