pstore/pmsg: drop bounce buffer
Removing a bounce buffer copy operation in the pmsg driver path is
always better. We also gain in overall performance by not requesting
a vmalloc on every write as this can cause precious RT tasks, such
as user facing media operation, to stall while memory is being
reclaimed. Added a write_buf_user to the pstore functions, a backup
platform write_buf_user that uses the small buffer that is part of
the instance, and implemented a ramoops write_buf_user that only
supports PSTORE_TYPE_PMSG.
Signed-off-by: Mark Salyzyn <salyzyn@android.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
diff --git a/include/linux/pstore.h b/include/linux/pstore.h
index 50d4752..92013cc 100644
--- a/include/linux/pstore.h
+++ b/include/linux/pstore.h
@@ -22,12 +22,13 @@
#ifndef _LINUX_PSTORE_H
#define _LINUX_PSTORE_H
-#include <linux/time.h>
+#include <linux/compiler.h>
+#include <linux/errno.h>
#include <linux/kmsg_dump.h>
#include <linux/mutex.h>
-#include <linux/types.h>
#include <linux/spinlock.h>
-#include <linux/errno.h>
+#include <linux/time.h>
+#include <linux/types.h>
/* types */
enum pstore_type_id {
@@ -68,6 +69,10 @@
enum kmsg_dump_reason reason, u64 *id,
unsigned int part, const char *buf, bool compressed,
size_t size, struct pstore_info *psi);
+ int (*write_buf_user)(enum pstore_type_id type,
+ enum kmsg_dump_reason reason, u64 *id,
+ unsigned int part, const char __user *buf,
+ bool compressed, size_t size, struct pstore_info *psi);
int (*erase)(enum pstore_type_id type, u64 id,
int count, struct timespec time,
struct pstore_info *psi);