Merge branch 'akpm' (patches from Andrew)

Merge fixes from Andrew Morton:
 "14 fixes"

* emailed patches from Andrew Morton <akpm@linux-foundation.org>:
  byteswap: try to avoid __builtin_constant_p gcc bug
  lib/stackdepot: avoid to return 0 handle
  mm: fix kcompactd hang during memory offlining
  modpost: fix module autoloading for OF devices with generic compatible property
  proc: prevent accessing /proc/<PID>/environ until it's ready
  mm/zswap: provide unique zpool name
  mm: thp: kvm: fix memory corruption in KVM with THP enabled
  MAINTAINERS: fix Rajendra Nayak's address
  mm, cma: prevent nr_isolated_* counters from going negative
  mm: update min_free_kbytes from khugepaged after core initialization
  huge pagecache: mmap_sem is unlocked when truncation splits pmd
  rapidio/mport_cdev: fix uapi type definitions
  mm: memcontrol: let v2 cgroups follow changes in system swappiness
  mm: thp: correct split_huge_pages file permission

3 files changed, 26 insertions, 271 deletions

diff --git a/include/linux/page-flags.h b/include/linux/page-flags.h
index f4ed4f1b0c77..6b052aa7b5b7 100644
--- a/include/linux/page-flags.h
+++ b/include/linux/page-flags.h
@@ -517,6 +517,27 @@ static inline int PageTransCompound(struct page *page)
 }
 
 /*
+ * PageTransCompoundMap is the same as PageTransCompound, but it also
+ * guarantees the primary MMU has the entire compound page mapped
+ * through pmd_trans_huge, which in turn guarantees the secondary MMUs
+ * can also map the entire compound page. This allows the secondary
+ * MMUs to call get_user_pages() only once for each compound page and
+ * to immediately map the entire compound page with a single secondary
+ * MMU fault. If there will be a pmd split later, the secondary MMUs
+ * will get an update through the MMU notifier invalidation through
+ * split_huge_pmd().
+ *
+ * Unlike PageTransCompound, this is safe to be called only while
+ * split_huge_pmd() cannot run from under us, like if protected by the
+ * MMU notifier, otherwise it may result in page->_mapcount < 0 false
+ * positives.
+ */
+static inline int PageTransCompoundMap(struct page *page)
+{
+	return PageTransCompound(page) && atomic_read(&page->_mapcount) < 0;
+}
+
+/*
  * PageTransTail returns true for both transparent huge pages
  * and hugetlbfs pages, so it should only be called when it's known
  * that hugetlbfs pages aren't involved.
@@ -559,6 +580,7 @@ static inline int TestClearPageDoubleMap(struct page *page)
 #else
 TESTPAGEFLAG_FALSE(TransHuge)
 TESTPAGEFLAG_FALSE(TransCompound)
+TESTPAGEFLAG_FALSE(TransCompoundMap)
 TESTPAGEFLAG_FALSE(TransTail)
 TESTPAGEFLAG_FALSE(DoubleMap)
 	TESTSETFLAG_FALSE(DoubleMap)
diff --git a/include/linux/rio_mport_cdev.h b/include/linux/rio_mport_cdev.h
deleted file mode 100644
index b65d19df76d2..000000000000
--- a/include/linux/rio_mport_cdev.h
+++ /dev/null
@@ -1,271 +0,0 @@
-/*
- * Copyright (c) 2015-2016, Integrated Device Technology Inc.
- * Copyright (c) 2015, Prodrive Technologies
- * Copyright (c) 2015, Texas Instruments Incorporated
- * Copyright (c) 2015, RapidIO Trade Association
- * All rights reserved.
- *
- * This software is available to you under a choice of one of two licenses.
- * You may choose to be licensed under the terms of the GNU General Public
- * License(GPL) Version 2, or the BSD-3 Clause license below:
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are met:
- *
- * 1. Redistributions of source code must retain the above copyright notice,
- * this list of conditions and the following disclaimer.
- *
- * 2. Redistributions in binary form must reproduce the above copyright notice,
- * this list of conditions and the following disclaimer in the documentation
- * and/or other materials provided with the distribution.
- *
- * 3. Neither the name of the copyright holder nor the names of its contributors
- * may be used to endorse or promote products derived from this software without
- * specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
- * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
- * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
- * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR
- * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
- * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
- * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
- * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
- * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
- * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
- * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-
-#ifndef _RIO_MPORT_CDEV_H_
-#define _RIO_MPORT_CDEV_H_
-
-#ifndef __user
-#define __user
-#endif
-
-struct rio_mport_maint_io {
-	uint32_t rioid;		/* destID of remote device */
-	uint32_t hopcount;	/* hopcount to remote device */
-	uint32_t offset;	/* offset in register space */
-	size_t length;		/* length in bytes */
-	void __user *buffer;	/* data buffer */
-};
-
-/*
- * Definitions for RapidIO data transfers:
- * - memory mapped (MAPPED)
- * - packet generation from memory (TRANSFER)
- */
-#define RIO_TRANSFER_MODE_MAPPED	(1 << 0)
-#define RIO_TRANSFER_MODE_TRANSFER	(1 << 1)
-#define RIO_CAP_DBL_SEND		(1 << 2)
-#define RIO_CAP_DBL_RECV		(1 << 3)
-#define RIO_CAP_PW_SEND			(1 << 4)
-#define RIO_CAP_PW_RECV			(1 << 5)
-#define RIO_CAP_MAP_OUTB		(1 << 6)
-#define RIO_CAP_MAP_INB			(1 << 7)
-
-struct rio_mport_properties {
-	uint16_t hdid;
-	uint8_t id;			/* Physical port ID */
-	uint8_t  index;
-	uint32_t flags;
-	uint32_t sys_size;		/* Default addressing size */
-	uint8_t  port_ok;
-	uint8_t  link_speed;
-	uint8_t  link_width;
-	uint32_t dma_max_sge;
-	uint32_t dma_max_size;
-	uint32_t dma_align;
-	uint32_t transfer_mode;		/* Default transfer mode */
-	uint32_t cap_sys_size;		/* Capable system sizes */
-	uint32_t cap_addr_size;		/* Capable addressing sizes */
-	uint32_t cap_transfer_mode;	/* Capable transfer modes */
-	uint32_t cap_mport;		/* Mport capabilities */
-};
-
-/*
- * Definitions for RapidIO events;
- * - incoming port-writes
- * - incoming doorbells
- */
-#define RIO_DOORBELL	(1 << 0)
-#define RIO_PORTWRITE	(1 << 1)
-
-struct rio_doorbell {
-	uint32_t rioid;
-	uint16_t payload;
-};
-
-struct rio_doorbell_filter {
-	uint32_t rioid;			/* 0xffffffff to match all ids */
-	uint16_t low;
-	uint16_t high;
-};
-
-
-struct rio_portwrite {
-	uint32_t payload[16];
-};
-
-struct rio_pw_filter {
-	uint32_t mask;
-	uint32_t low;
-	uint32_t high;
-};
-
-/* RapidIO base address for inbound requests set to value defined below
- * indicates that no specific RIO-to-local address translation is requested
- * and driver should use direct (one-to-one) address mapping.
-*/
-#define RIO_MAP_ANY_ADDR	(uint64_t)(~((uint64_t) 0))
-
-struct rio_mmap {
-	uint32_t rioid;
-	uint64_t rio_addr;
-	uint64_t length;
-	uint64_t handle;
-	void *address;
-};
-
-struct rio_dma_mem {
-	uint64_t length;		/* length of DMA memory */
-	uint64_t dma_handle;		/* handle associated with this memory */
-	void *buffer;			/* pointer to this memory */
-};
-
-
-struct rio_event {
-	unsigned int header;	/* event type RIO_DOORBELL or RIO_PORTWRITE */
-	union {
-		struct rio_doorbell doorbell;	/* header for RIO_DOORBELL */
-		struct rio_portwrite portwrite; /* header for RIO_PORTWRITE */
-	} u;
-};
-
-enum rio_transfer_sync {
-	RIO_TRANSFER_SYNC,	/* synchronous transfer */
-	RIO_TRANSFER_ASYNC,	/* asynchronous transfer */
-	RIO_TRANSFER_FAF,	/* fire-and-forget transfer */
-};
-
-enum rio_transfer_dir {
-	RIO_TRANSFER_DIR_READ,	/* Read operation */
-	RIO_TRANSFER_DIR_WRITE,	/* Write operation */
-};
-
-/*
- * RapidIO data exchange transactions are lists of individual transfers. Each
- * transfer exchanges data between two RapidIO devices by remote direct memory
- * access and has its own completion code.
- *
- * The RapidIO specification defines four types of data exchange requests:
- * NREAD, NWRITE, SWRITE and NWRITE_R. The RapidIO DMA channel interface allows
- * to specify the required type of write operation or combination of them when
- * only the last data packet requires response.
- *
- * NREAD:    read up to 256 bytes from remote device memory into local memory
- * NWRITE:   write up to 256 bytes from local memory to remote device memory
- *           without confirmation
- * SWRITE:   as NWRITE, but all addresses and payloads must be 64-bit aligned
- * NWRITE_R: as NWRITE, but expect acknowledgment from remote device.
- *
- * The default exchange is chosen from NREAD and any of the WRITE modes as the
- * driver sees fit. For write requests the user can explicitly choose between
- * any of the write modes for each transaction.
- */
-enum rio_exchange {
-	RIO_EXCHANGE_DEFAULT,	/* Default method */
-	RIO_EXCHANGE_NWRITE,	/* All packets using NWRITE */
-	RIO_EXCHANGE_SWRITE,	/* All packets using SWRITE */
-	RIO_EXCHANGE_NWRITE_R,	/* Last packet NWRITE_R, others NWRITE */
-	RIO_EXCHANGE_SWRITE_R,	/* Last packet NWRITE_R, others SWRITE */
-	RIO_EXCHANGE_NWRITE_R_ALL, /* All packets using NWRITE_R */
-};
-
-struct rio_transfer_io {
-	uint32_t rioid;			/* Target destID */
-	uint64_t rio_addr;		/* Address in target's RIO mem space */
-	enum rio_exchange method;	/* Data exchange method */
-	void __user *loc_addr;
-	uint64_t handle;
-	uint64_t offset;		/* Offset in buffer */
-	uint64_t length;		/* Length in bytes */
-	uint32_t completion_code;	/* Completion code for this transfer */
-};
-
-struct rio_transaction {
-	uint32_t transfer_mode;		/* Data transfer mode */
-	enum rio_transfer_sync sync;	/* Synchronization method */
-	enum rio_transfer_dir dir;	/* Transfer direction */
-	size_t count;			/* Number of transfers */
-	struct rio_transfer_io __user *block;	/* Array of <count> transfers */
-};
-
-struct rio_async_tx_wait {
-	uint32_t token;		/* DMA transaction ID token */
-	uint32_t timeout;	/* Wait timeout in msec, if 0 use default TO */
-};
-
-#define RIO_MAX_DEVNAME_SZ	20
-
-struct rio_rdev_info {
-	uint32_t destid;
-	uint8_t hopcount;
-	uint32_t comptag;
-	char name[RIO_MAX_DEVNAME_SZ + 1];
-};
-
-/* Driver IOCTL codes */
-#define RIO_MPORT_DRV_MAGIC           'm'
-
-#define RIO_MPORT_MAINT_HDID_SET	\
-	_IOW(RIO_MPORT_DRV_MAGIC, 1, uint16_t)
-#define RIO_MPORT_MAINT_COMPTAG_SET	\
-	_IOW(RIO_MPORT_DRV_MAGIC, 2, uint32_t)
-#define RIO_MPORT_MAINT_PORT_IDX_GET	\
-	_IOR(RIO_MPORT_DRV_MAGIC, 3, uint32_t)
-#define RIO_MPORT_GET_PROPERTIES \
-	_IOR(RIO_MPORT_DRV_MAGIC, 4, struct rio_mport_properties)
-#define RIO_MPORT_MAINT_READ_LOCAL \
-	_IOR(RIO_MPORT_DRV_MAGIC, 5, struct rio_mport_maint_io)
-#define RIO_MPORT_MAINT_WRITE_LOCAL \
-	_IOW(RIO_MPORT_DRV_MAGIC, 6, struct rio_mport_maint_io)
-#define RIO_MPORT_MAINT_READ_REMOTE \
-	_IOR(RIO_MPORT_DRV_MAGIC, 7, struct rio_mport_maint_io)
-#define RIO_MPORT_MAINT_WRITE_REMOTE \
-	_IOW(RIO_MPORT_DRV_MAGIC, 8, struct rio_mport_maint_io)
-#define RIO_ENABLE_DOORBELL_RANGE	\
-	_IOW(RIO_MPORT_DRV_MAGIC, 9, struct rio_doorbell_filter)
-#define RIO_DISABLE_DOORBELL_RANGE	\
-	_IOW(RIO_MPORT_DRV_MAGIC, 10, struct rio_doorbell_filter)
-#define RIO_ENABLE_PORTWRITE_RANGE	\
-	_IOW(RIO_MPORT_DRV_MAGIC, 11, struct rio_pw_filter)
-#define RIO_DISABLE_PORTWRITE_RANGE	\
-	_IOW(RIO_MPORT_DRV_MAGIC, 12, struct rio_pw_filter)
-#define RIO_SET_EVENT_MASK		\
-	_IOW(RIO_MPORT_DRV_MAGIC, 13, unsigned int)
-#define RIO_GET_EVENT_MASK		\
-	_IOR(RIO_MPORT_DRV_MAGIC, 14, unsigned int)
-#define RIO_MAP_OUTBOUND \
-	_IOWR(RIO_MPORT_DRV_MAGIC, 15, struct rio_mmap)
-#define RIO_UNMAP_OUTBOUND \
-	_IOW(RIO_MPORT_DRV_MAGIC, 16, struct rio_mmap)
-#define RIO_MAP_INBOUND \
-	_IOWR(RIO_MPORT_DRV_MAGIC, 17, struct rio_mmap)
-#define RIO_UNMAP_INBOUND \
-	_IOW(RIO_MPORT_DRV_MAGIC, 18, uint64_t)
-#define RIO_ALLOC_DMA \
-	_IOWR(RIO_MPORT_DRV_MAGIC, 19, struct rio_dma_mem)
-#define RIO_FREE_DMA \
-	_IOW(RIO_MPORT_DRV_MAGIC, 20, uint64_t)
-#define RIO_TRANSFER \
-	_IOWR(RIO_MPORT_DRV_MAGIC, 21, struct rio_transaction)
-#define RIO_WAIT_FOR_ASYNC \
-	_IOW(RIO_MPORT_DRV_MAGIC, 22, struct rio_async_tx_wait)
-#define RIO_DEV_ADD \
-	_IOW(RIO_MPORT_DRV_MAGIC, 23, struct rio_rdev_info)
-#define RIO_DEV_DEL \
-	_IOW(RIO_MPORT_DRV_MAGIC, 24, struct rio_rdev_info)
-
-#endif /* _RIO_MPORT_CDEV_H_ */
diff --git a/include/linux/swap.h b/include/linux/swap.h
index 2b83359c19ca..0a4cd4703f40 100644
--- a/include/linux/swap.h
+++ b/include/linux/swap.h
@@ -533,6 +533,10 @@ static inline swp_entry_t get_swap_page(void)
 #ifdef CONFIG_MEMCG
 static inline int mem_cgroup_swappiness(struct mem_cgroup *memcg)
 {
+	/* Cgroup2 doesn't have per-cgroup swappiness */
+	if (cgroup_subsys_on_dfl(memory_cgrp_subsys))
+		return vm_swappiness;
+
 	/* root ? */
 	if (mem_cgroup_disabled() || !memcg->css.parent)
 		return vm_swappiness;