From 6cbafbd144334616156c48d343ff323837df1fb3 Mon Sep 17 00:00:00 2001
From: Mark Salyzyn <salyzyn@google.com>
Date: Wed, 31 Aug 2016 08:09:04 -0700
Subject: FROMLIST: pstore: drop pmsg bounce buffer

(from https://lkml.org/lkml/2016/9/1/428)
(cherry pick from android-3.10 commit b58133100b38f2bf83cad2d7097417a3a196ed0b)

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@google.com>
Bug: 31057326
Change-Id: I4cdee1cd31467aa3e6c605bce2fbd4de5b0f8caa
---
 include/linux/pstore.h     | 11 ++++++++---
 include/linux/pstore_ram.h |  7 +++++--
 2 files changed, 13 insertions(+), 5 deletions(-)

(limited to 'include')

diff --git a/include/linux/pstore.h b/include/linux/pstore.h
index 289884121..d1482b779 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 {
@@ -61,6 +62,10 @@ struct pstore_info {
 			enum kmsg_dump_reason reason, u64 *id,
 			unsigned int part, const char *buf, 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);
diff --git a/include/linux/pstore_ram.h b/include/linux/pstore_ram.h
index 712757f32..45ac5a0d2 100644
--- a/include/linux/pstore_ram.h
+++ b/include/linux/pstore_ram.h
@@ -17,11 +17,12 @@
 #ifndef __LINUX_PSTORE_RAM_H__
 #define __LINUX_PSTORE_RAM_H__
 
+#include <linux/compiler.h>
 #include <linux/device.h>
+#include <linux/init.h>
 #include <linux/kernel.h>
 #include <linux/list.h>
 #include <linux/types.h>
-#include <linux/init.h>
 
 struct persistent_ram_buffer;
 struct rs_control;
@@ -59,7 +60,9 @@ void persistent_ram_free(struct persistent_ram_zone *prz);
 void persistent_ram_zap(struct persistent_ram_zone *prz);
 
 int persistent_ram_write(struct persistent_ram_zone *prz, const void *s,
-	unsigned int count);
+			 unsigned int count);
+int persistent_ram_write_user(struct persistent_ram_zone *prz,
+			      const void __user *s, unsigned int count);
 
 void persistent_ram_save_old(struct persistent_ram_zone *prz);
 size_t persistent_ram_old_size(struct persistent_ram_zone *prz);
-- 
cgit v1.2.3