[PATCH 4/6] kernel: move use_mm/unuse_mm to kthread.c

From: Christoph Hellwig
Date: Sat Apr 04 2020 - 05:41:31 EST


These helpers are only for use with kernel threads, and I will tie them
more into the kthread infrastructure going forward. Also move the
prototypes to kthread.h - mmu_context.h was a little weird to start with
as it otherwise contains very low-level MM bits.

Signed-off-by: Christoph Hellwig <hch@xxxxxx>
---
drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd.h | 1 +
.../drm/amd/amdgpu/amdgpu_amdkfd_arcturus.c | 1 -
.../drm/amd/amdgpu/amdgpu_amdkfd_gfx_v10.c | 1 -
.../gpu/drm/amd/amdgpu/amdgpu_amdkfd_gfx_v7.c | 2 -
.../gpu/drm/amd/amdgpu/amdgpu_amdkfd_gfx_v8.c | 2 -
.../gpu/drm/amd/amdgpu/amdgpu_amdkfd_gfx_v9.c | 2 -
drivers/gpu/drm/i915/gvt/kvmgt.c | 2 +-
drivers/usb/gadget/function/f_fs.c | 2 +-
drivers/usb/gadget/legacy/inode.c | 2 +-
drivers/vhost/vhost.c | 1 -
fs/aio.c | 1 -
fs/io-wq.c | 1 -
fs/io_uring.c | 1 -
include/linux/kthread.h | 5 ++
include/linux/mmu_context.h | 5 --
kernel/kthread.c | 56 ++++++++++++++++
mm/Makefile | 2 +-
mm/mmu_context.c | 64 -------------------
18 files changed, 66 insertions(+), 85 deletions(-)
delete mode 100644 mm/mmu_context.c

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd.h b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd.h
index 4db143c19dcc..bce5e93fefc8 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd.h
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd.h
@@ -27,6 +27,7 @@

#include <linux/types.h>
#include <linux/mm.h>
+#include <linux/kthread.h>
#include <linux/workqueue.h>
#include <kgd_kfd_interface.h>
#include <drm/ttm/ttm_execbuf_util.h>
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_arcturus.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_arcturus.c
index 6529caca88fe..35d4a5ab0228 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_arcturus.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_arcturus.c
@@ -22,7 +22,6 @@
#include <linux/module.h>
#include <linux/fdtable.h>
#include <linux/uaccess.h>
-#include <linux/mmu_context.h>
#include <linux/firmware.h>
#include "amdgpu.h"
#include "amdgpu_amdkfd.h"
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gfx_v10.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gfx_v10.c
index 4ec6d0c03201..b1655054b919 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gfx_v10.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gfx_v10.c
@@ -19,7 +19,6 @@
* ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
* OTHER DEALINGS IN THE SOFTWARE.
*/
-#include <linux/mmu_context.h>
#include "amdgpu.h"
#include "amdgpu_amdkfd.h"
#include "gc/gc_10_1_0_offset.h"
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gfx_v7.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gfx_v7.c
index 0b7e78748540..7d01420c0c85 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gfx_v7.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gfx_v7.c
@@ -20,8 +20,6 @@
* OTHER DEALINGS IN THE SOFTWARE.
*/

-#include <linux/mmu_context.h>
-
#include "amdgpu.h"
#include "amdgpu_amdkfd.h"
#include "cikd.h"
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gfx_v8.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gfx_v8.c
index ccd635b812b5..635cd1a26bed 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gfx_v8.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gfx_v8.c
@@ -20,8 +20,6 @@
* OTHER DEALINGS IN THE SOFTWARE.
*/

-#include <linux/mmu_context.h>
-
#include "amdgpu.h"
#include "amdgpu_amdkfd.h"
#include "gfx_v8_0.h"
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gfx_v9.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gfx_v9.c
index df841c2ac5e7..c7fd0c47b254 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gfx_v9.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gfx_v9.c
@@ -19,8 +19,6 @@
* ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
* OTHER DEALINGS IN THE SOFTWARE.
*/
-#include <linux/mmu_context.h>
-
#include "amdgpu.h"
#include "amdgpu_amdkfd.h"
#include "gc/gc_9_0_offset.h"
diff --git a/drivers/gpu/drm/i915/gvt/kvmgt.c b/drivers/gpu/drm/i915/gvt/kvmgt.c
index 5848400620b4..dee01c371bf5 100644
--- a/drivers/gpu/drm/i915/gvt/kvmgt.c
+++ b/drivers/gpu/drm/i915/gvt/kvmgt.c
@@ -31,7 +31,7 @@
#include <linux/init.h>
#include <linux/device.h>
#include <linux/mm.h>
-#include <linux/mmu_context.h>
+#include <linux/kthread.h>
#include <linux/sched/mm.h>
#include <linux/types.h>
#include <linux/list.h>
diff --git a/drivers/usb/gadget/function/f_fs.c b/drivers/usb/gadget/function/f_fs.c
index c81023b195c3..c57b1b2507c6 100644
--- a/drivers/usb/gadget/function/f_fs.c
+++ b/drivers/usb/gadget/function/f_fs.c
@@ -32,7 +32,7 @@
#include <linux/usb/functionfs.h>

#include <linux/aio.h>
-#include <linux/mmu_context.h>
+#include <linux/kthread.h>
#include <linux/poll.h>
#include <linux/eventfd.h>

diff --git a/drivers/usb/gadget/legacy/inode.c b/drivers/usb/gadget/legacy/inode.c
index aa0de9e35afa..8b5233888bf8 100644
--- a/drivers/usb/gadget/legacy/inode.c
+++ b/drivers/usb/gadget/legacy/inode.c
@@ -21,7 +21,7 @@
#include <linux/sched.h>
#include <linux/slab.h>
#include <linux/poll.h>
-#include <linux/mmu_context.h>
+#include <linux/kthread.h>
#include <linux/aio.h>
#include <linux/uio.h>
#include <linux/refcount.h>
diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c
index f44340b41494..4e9ce54869af 100644
--- a/drivers/vhost/vhost.c
+++ b/drivers/vhost/vhost.c
@@ -14,7 +14,6 @@
#include <linux/vhost.h>
#include <linux/uio.h>
#include <linux/mm.h>
-#include <linux/mmu_context.h>
#include <linux/miscdevice.h>
#include <linux/mutex.h>
#include <linux/poll.h>
diff --git a/fs/aio.c b/fs/aio.c
index 5f3d3d814928..328829f0343b 100644
--- a/fs/aio.c
+++ b/fs/aio.c
@@ -27,7 +27,6 @@
#include <linux/file.h>
#include <linux/mm.h>
#include <linux/mman.h>
-#include <linux/mmu_context.h>
#include <linux/percpu.h>
#include <linux/slab.h>
#include <linux/timer.h>
diff --git a/fs/io-wq.c b/fs/io-wq.c
index cc5cf2209fb0..c49c2bdbafb5 100644
--- a/fs/io-wq.c
+++ b/fs/io-wq.c
@@ -10,7 +10,6 @@
#include <linux/errno.h>
#include <linux/sched/signal.h>
#include <linux/mm.h>
-#include <linux/mmu_context.h>
#include <linux/sched/mm.h>
#include <linux/percpu.h>
#include <linux/slab.h>
diff --git a/fs/io_uring.c b/fs/io_uring.c
index 358f97be9c7b..27a4ecb724ca 100644
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -55,7 +55,6 @@
#include <linux/fdtable.h>
#include <linux/mm.h>
#include <linux/mman.h>
-#include <linux/mmu_context.h>
#include <linux/percpu.h>
#include <linux/slab.h>
#include <linux/kthread.h>
diff --git a/include/linux/kthread.h b/include/linux/kthread.h
index 8bbcaad7ef0f..c2d40c9672d6 100644
--- a/include/linux/kthread.h
+++ b/include/linux/kthread.h
@@ -5,6 +5,8 @@
#include <linux/err.h>
#include <linux/sched.h>

+struct mm_struct;
+
__printf(4, 5)
struct task_struct *kthread_create_on_node(int (*threadfn)(void *data),
void *data,
@@ -198,6 +200,9 @@ bool kthread_cancel_delayed_work_sync(struct kthread_delayed_work *work);

void kthread_destroy_worker(struct kthread_worker *worker);

+void use_mm(struct mm_struct *mm);
+void unuse_mm(struct mm_struct *mm);
+
struct cgroup_subsys_state;

#ifdef CONFIG_BLK_CGROUP
diff --git a/include/linux/mmu_context.h b/include/linux/mmu_context.h
index d9a543a9e1cc..c51a84132d7c 100644
--- a/include/linux/mmu_context.h
+++ b/include/linux/mmu_context.h
@@ -4,11 +4,6 @@

#include <asm/mmu_context.h>

-struct mm_struct;
-
-void use_mm(struct mm_struct *mm);
-void unuse_mm(struct mm_struct *mm);
-
/* Architectures that care about IRQ state in switch_mm can override this. */
#ifndef switch_mm_irqs_off
# define switch_mm_irqs_off switch_mm
diff --git a/kernel/kthread.c b/kernel/kthread.c
index bfbfa481be3a..ce4610316377 100644
--- a/kernel/kthread.c
+++ b/kernel/kthread.c
@@ -1,13 +1,17 @@
// SPDX-License-Identifier: GPL-2.0-only
/* Kernel thread helper functions.
* Copyright (C) 2004 IBM Corporation, Rusty Russell.
+ * Copyright (C) 2009 Red Hat, Inc.
*
* Creation is done via kthreadd, so that we get a clean environment
* even if we're invoked from userspace (think modprobe, hotplug cpu,
* etc.).
*/
#include <uapi/linux/sched/types.h>
+#include <linux/mm.h>
+#include <linux/mmu_context.h>
#include <linux/sched.h>
+#include <linux/sched/mm.h>
#include <linux/sched/task.h>
#include <linux/kthread.h>
#include <linux/completion.h>
@@ -25,6 +29,7 @@
#include <linux/numa.h>
#include <trace/events/sched.h>

+
static DEFINE_SPINLOCK(kthread_create_lock);
static LIST_HEAD(kthread_create_list);
struct task_struct *kthreadd_task;
@@ -1203,6 +1208,57 @@ void kthread_destroy_worker(struct kthread_worker *worker)
}
EXPORT_SYMBOL(kthread_destroy_worker);

+/*
+ * use_mm
+ * Makes the calling kernel thread take on the specified
+ * mm context.
+ * (Note: this routine is intended to be called only
+ * from a kernel thread context)
+ */
+void use_mm(struct mm_struct *mm)
+{
+ struct mm_struct *active_mm;
+ struct task_struct *tsk = current;
+
+ task_lock(tsk);
+ active_mm = tsk->active_mm;
+ if (active_mm != mm) {
+ mmgrab(mm);
+ tsk->active_mm = mm;
+ }
+ tsk->mm = mm;
+ switch_mm(active_mm, mm, tsk);
+ task_unlock(tsk);
+#ifdef finish_arch_post_lock_switch
+ finish_arch_post_lock_switch();
+#endif
+
+ if (active_mm != mm)
+ mmdrop(active_mm);
+}
+EXPORT_SYMBOL_GPL(use_mm);
+
+/*
+ * unuse_mm
+ * Reverses the effect of use_mm, i.e. releases the
+ * specified mm context which was earlier taken on
+ * by the calling kernel thread
+ * (Note: this routine is intended to be called only
+ * from a kernel thread context)
+ */
+void unuse_mm(struct mm_struct *mm)
+{
+ struct task_struct *tsk = current;
+
+ task_lock(tsk);
+ sync_mm_rss(mm);
+ tsk->mm = NULL;
+ /* active_mm is still 'mm' */
+ enter_lazy_tlb(mm, tsk);
+ task_unlock(tsk);
+}
+EXPORT_SYMBOL_GPL(unuse_mm);
+
#ifdef CONFIG_BLK_CGROUP
/**
* kthread_associate_blkcg - associate blkcg to current kthread
diff --git a/mm/Makefile b/mm/Makefile
index dbc8346d16ca..0af4ee81aed2 100644
--- a/mm/Makefile
+++ b/mm/Makefile
@@ -41,7 +41,7 @@ obj-y := filemap.o mempool.o oom_kill.o fadvise.o \
maccess.o page-writeback.o \
readahead.o swap.o truncate.o vmscan.o shmem.o \
util.o mmzone.o vmstat.o backing-dev.o \
- mm_init.o mmu_context.o percpu.o slab_common.o \
+ mm_init.o percpu.o slab_common.o \
compaction.o vmacache.o \
interval_tree.o list_lru.o workingset.o \
debug.o gup.o $(mmu-y)
diff --git a/mm/mmu_context.c b/mm/mmu_context.c
deleted file mode 100644
index 3e612ae748e9..000000000000
--- a/mm/mmu_context.c
+++ /dev/null
@@ -1,64 +0,0 @@
-/* Copyright (C) 2009 Red Hat, Inc.
- *
- * See ../COPYING for licensing terms.
- */
-
-#include <linux/mm.h>
-#include <linux/sched.h>
-#include <linux/sched/mm.h>
-#include <linux/sched/task.h>
-#include <linux/mmu_context.h>
-#include <linux/export.h>
-
-#include <asm/mmu_context.h>
-
-/*
- * use_mm
- * Makes the calling kernel thread take on the specified
- * mm context.
- * (Note: this routine is intended to be called only
- * from a kernel thread context)
- */
-void use_mm(struct mm_struct *mm)
-{
- struct mm_struct *active_mm;
- struct task_struct *tsk = current;
-
- task_lock(tsk);
- active_mm = tsk->active_mm;
- if (active_mm != mm) {
- mmgrab(mm);
- tsk->active_mm = mm;
- }
- tsk->mm = mm;
- switch_mm(active_mm, mm, tsk);
- task_unlock(tsk);
-#ifdef finish_arch_post_lock_switch
- finish_arch_post_lock_switch();
-#endif
-
- if (active_mm != mm)
- mmdrop(active_mm);
-}
-EXPORT_SYMBOL_GPL(use_mm);
-
-/*
- * unuse_mm
- * Reverses the effect of use_mm, i.e. releases the
- * specified mm context which was earlier taken on
- * by the calling kernel thread
- * (Note: this routine is intended to be called only
- * from a kernel thread context)
- */
-void unuse_mm(struct mm_struct *mm)
-{
- struct task_struct *tsk = current;
-
- task_lock(tsk);
- sync_mm_rss(mm);
- tsk->mm = NULL;
- /* active_mm is still 'mm' */
- enter_lazy_tlb(mm, tsk);
- task_unlock(tsk);
-}
-EXPORT_SYMBOL_GPL(unuse_mm);
--
2.25.1