Update Linux to v5.4.2

Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/drivers/misc/sgi-gru/Makefile b/drivers/misc/sgi-gru/Makefile
index 0003a1d..8132116 100644
--- a/drivers/misc/sgi-gru/Makefile
+++ b/drivers/misc/sgi-gru/Makefile
@@ -1,3 +1,4 @@
+# SPDX-License-Identifier: GPL-2.0-only
 ccflags-$(CONFIG_SGI_GRU_DEBUG)	:= -DDEBUG
 
 obj-$(CONFIG_SGI_GRU) := gru.o
diff --git a/drivers/misc/sgi-gru/grufault.c b/drivers/misc/sgi-gru/grufault.c
index 93be82f..4b713a8 100644
--- a/drivers/misc/sgi-gru/grufault.c
+++ b/drivers/misc/sgi-gru/grufault.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
 /*
  * SN Platform GRU Driver
  *
@@ -8,20 +9,6 @@
  * the user CB.
  *
  *  Copyright (c) 2008 Silicon Graphics, Inc.  All Rights Reserved.
- *
- *  This program is free software; you can redistribute it and/or modify
- *  it under the terms of the GNU General Public License as published by
- *  the Free Software Foundation; either version 2 of the License, or
- *  (at your option) any later version.
- *
- *  This program is distributed in the hope that it will be useful,
- *  but WITHOUT ANY WARRANTY; without even the implied warranty of
- *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- *  GNU General Public License for more details.
- *
- *  You should have received a copy of the GNU General Public License
- *  along with this program; if not, write to the Free Software
- *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
  */
 
 #include <linux/kernel.h>
@@ -616,8 +603,8 @@
 	for_each_possible_blade(blade) {
 		if (uv_blade_nr_possible_cpus(blade))
 			continue;
-		 gru_intr(0, blade);
-		 gru_intr(1, blade);
+		gru_intr(0, blade);
+		gru_intr(1, blade);
 	}
 	return IRQ_HANDLED;
 }
diff --git a/drivers/misc/sgi-gru/grufile.c b/drivers/misc/sgi-gru/grufile.c
index 104a05f..9d04231 100644
--- a/drivers/misc/sgi-gru/grufile.c
+++ b/drivers/misc/sgi-gru/grufile.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
 /*
  * SN Platform GRU Driver
  *
@@ -7,20 +8,6 @@
  * This also incudes the driver initialization code.
  *
  *  Copyright (c) 2008-2014 Silicon Graphics, Inc.  All Rights Reserved.
- *
- *  This program is free software; you can redistribute it and/or modify
- *  it under the terms of the GNU General Public License as published by
- *  the Free Software Foundation; either version 2 of the License, or
- *  (at your option) any later version.
- *
- *  This program is distributed in the hope that it will be useful,
- *  but WITHOUT ANY WARRANTY; without even the implied warranty of
- *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- *  GNU General Public License for more details.
- *
- *  You should have received a copy of the GNU General Public License
- *  along with this program; if not, write to the Free Software
- *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
  */
 
 #include <linux/module.h>
@@ -586,6 +573,7 @@
 	gru_free_tables();
 	misc_deregister(&gru_miscdev);
 	gru_proc_exit();
+	mmu_notifier_synchronize();
 }
 
 static const struct file_operations gru_fops = {
diff --git a/drivers/misc/sgi-gru/gruhandles.c b/drivers/misc/sgi-gru/gruhandles.c
index 1ee8e82..f7224f9 100644
--- a/drivers/misc/sgi-gru/gruhandles.c
+++ b/drivers/misc/sgi-gru/gruhandles.c
@@ -1,21 +1,8 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
 /*
  *              GRU KERNEL MCS INSTRUCTIONS
  *
  *  Copyright (c) 2008 Silicon Graphics, Inc.  All Rights Reserved.
- *
- *  This program is free software; you can redistribute it and/or modify
- *  it under the terms of the GNU General Public License as published by
- *  the Free Software Foundation; either version 2 of the License, or
- *  (at your option) any later version.
- *
- *  This program is distributed in the hope that it will be useful,
- *  but WITHOUT ANY WARRANTY; without even the implied warranty of
- *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- *  GNU General Public License for more details.
- *
- *  You should have received a copy of the GNU General Public License
- *  along with this program; if not, write to the Free Software
- *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
  */
 
 #include <linux/kernel.h>
diff --git a/drivers/misc/sgi-gru/gruhandles.h b/drivers/misc/sgi-gru/gruhandles.h
index 3d7bd36..5a498bf 100644
--- a/drivers/misc/sgi-gru/gruhandles.h
+++ b/drivers/misc/sgi-gru/gruhandles.h
@@ -1,23 +1,10 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
 /*
  * SN Platform GRU Driver
  *
  *              GRU HANDLE DEFINITION
  *
  *  Copyright (c) 2008 Silicon Graphics, Inc.  All Rights Reserved.
- *
- *  This program is free software; you can redistribute it and/or modify
- *  it under the terms of the GNU General Public License as published by
- *  the Free Software Foundation; either version 2 of the License, or
- *  (at your option) any later version.
- *
- *  This program is distributed in the hope that it will be useful,
- *  but WITHOUT ANY WARRANTY; without even the implied warranty of
- *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- *  GNU General Public License for more details.
- *
- *  You should have received a copy of the GNU General Public License
- *  along with this program; if not, write to the Free Software
- *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
  */
 
 #ifndef __GRUHANDLES_H__
diff --git a/drivers/misc/sgi-gru/grukdump.c b/drivers/misc/sgi-gru/grukdump.c
index 1540a77..9869f4f 100644
--- a/drivers/misc/sgi-gru/grukdump.c
+++ b/drivers/misc/sgi-gru/grukdump.c
@@ -1,23 +1,10 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
 /*
  * SN Platform GRU Driver
  *
  *            Dump GRU State
  *
  *  Copyright (c) 2008 Silicon Graphics, Inc.  All Rights Reserved.
- *
- *  This program is free software; you can redistribute it and/or modify
- *  it under the terms of the GNU General Public License as published by
- *  the Free Software Foundation; either version 2 of the License, or
- *  (at your option) any later version.
- *
- *  This program is distributed in the hope that it will be useful,
- *  but WITHOUT ANY WARRANTY; without even the implied warranty of
- *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- *  GNU General Public License for more details.
- *
- *  You should have received a copy of the GNU General Public License
- *  along with this program; if not, write to the Free Software
- *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
  */
 
 #include <linux/kernel.h>
diff --git a/drivers/misc/sgi-gru/grukservices.c b/drivers/misc/sgi-gru/grukservices.c
index 0307690..0197441 100644
--- a/drivers/misc/sgi-gru/grukservices.c
+++ b/drivers/misc/sgi-gru/grukservices.c
@@ -1,23 +1,10 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
 /*
  * SN Platform GRU Driver
  *
  *              KERNEL SERVICES THAT USE THE GRU
  *
  *  Copyright (c) 2008 Silicon Graphics, Inc.  All Rights Reserved.
- *
- *  This program is free software; you can redistribute it and/or modify
- *  it under the terms of the GNU General Public License as published by
- *  the Free Software Foundation; either version 2 of the License, or
- *  (at your option) any later version.
- *
- *  This program is distributed in the hope that it will be useful,
- *  but WITHOUT ANY WARRANTY; without even the implied warranty of
- *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- *  GNU General Public License for more details.
- *
- *  You should have received a copy of the GNU General Public License
- *  along with this program; if not, write to the Free Software
- *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
  */
 
 #include <linux/kernel.h>
@@ -634,7 +621,7 @@
 			break;
 		case CBSS_PAGE_OVERFLOW:
 			STAT(mesq_noop_page_overflow);
-			/* fallthru */
+			/* fall through */
 		default:
 			BUG();
 		}
@@ -792,7 +779,7 @@
 		break;
 	case CBSS_PAGE_OVERFLOW:
 		STAT(mesq_page_overflow);
-		/* fallthru */
+		/* fall through */
 	default:
 		BUG();
 	}
diff --git a/drivers/misc/sgi-gru/grukservices.h b/drivers/misc/sgi-gru/grukservices.h
index 02aa94d..510e45e 100644
--- a/drivers/misc/sgi-gru/grukservices.h
+++ b/drivers/misc/sgi-gru/grukservices.h
@@ -1,20 +1,7 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
 
 /*
  *  Copyright (c) 2008 Silicon Graphics, Inc.  All Rights Reserved.
- *
- *  This program is free software; you can redistribute it and/or modify
- *  it under the terms of the GNU General Public License as published by
- *  the Free Software Foundation; either version 2 of the License, or
- *  (at your option) any later version.
- *
- *  This program is distributed in the hope that it will be useful,
- *  but WITHOUT ANY WARRANTY; without even the implied warranty of
- *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- *  GNU General Public License for more details.
- *
- *  You should have received a copy of the GNU General Public License
- *  along with this program; if not, write to the Free Software
- *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
  */
 #ifndef __GRU_KSERVICES_H_
 #define __GRU_KSERVICES_H_
diff --git a/drivers/misc/sgi-gru/grumain.c b/drivers/misc/sgi-gru/grumain.c
index ab174f2..40ac59d 100644
--- a/drivers/misc/sgi-gru/grumain.c
+++ b/drivers/misc/sgi-gru/grumain.c
@@ -1,23 +1,10 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
 /*
  * SN Platform GRU Driver
  *
  *            DRIVER TABLE MANAGER + GRU CONTEXT LOAD/UNLOAD
  *
  *  Copyright (c) 2008 Silicon Graphics, Inc.  All Rights Reserved.
- *
- *  This program is free software; you can redistribute it and/or modify
- *  it under the terms of the GNU General Public License as published by
- *  the Free Software Foundation; either version 2 of the License, or
- *  (at your option) any later version.
- *
- *  This program is distributed in the hope that it will be useful,
- *  but WITHOUT ANY WARRANTY; without even the implied warranty of
- *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- *  GNU General Public License for more details.
- *
- *  You should have received a copy of the GNU General Public License
- *  along with this program; if not, write to the Free Software
- *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
  */
 
 #include <linux/kernel.h>
diff --git a/drivers/misc/sgi-gru/gruprocfs.c b/drivers/misc/sgi-gru/gruprocfs.c
index 42ea2ec..3a8d76d 100644
--- a/drivers/misc/sgi-gru/gruprocfs.c
+++ b/drivers/misc/sgi-gru/gruprocfs.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
 /*
  * SN Platform GRU Driver
  *
@@ -6,20 +7,6 @@
  * This file supports the /proc interfaces for the GRU driver
  *
  *  Copyright (c) 2008 Silicon Graphics, Inc.  All Rights Reserved.
- *
- *  This program is free software; you can redistribute it and/or modify
- *  it under the terms of the GNU General Public License as published by
- *  the Free Software Foundation; either version 2 of the License, or
- *  (at your option) any later version.
- *
- *  This program is distributed in the hope that it will be useful,
- *  but WITHOUT ANY WARRANTY; without even the implied warranty of
- *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- *  GNU General Public License for more details.
- *
- *  You should have received a copy of the GNU General Public License
- *  along with this program; if not, write to the Free Software
- *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
  */
 
 #include <linux/proc_fs.h>
diff --git a/drivers/misc/sgi-gru/grutables.h b/drivers/misc/sgi-gru/grutables.h
index 3e041b6..a7e44b2 100644
--- a/drivers/misc/sgi-gru/grutables.h
+++ b/drivers/misc/sgi-gru/grutables.h
@@ -1,23 +1,10 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
 /*
  * SN Platform GRU Driver
  *
  *            GRU DRIVER TABLES, MACROS, externs, etc
  *
  *  Copyright (c) 2008 Silicon Graphics, Inc.  All Rights Reserved.
- *
- *  This program is free software; you can redistribute it and/or modify
- *  it under the terms of the GNU General Public License as published by
- *  the Free Software Foundation; either version 2 of the License, or
- *  (at your option) any later version.
- *
- *  This program is distributed in the hope that it will be useful,
- *  but WITHOUT ANY WARRANTY; without even the implied warranty of
- *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- *  GNU General Public License for more details.
- *
- *  You should have received a copy of the GNU General Public License
- *  along with this program; if not, write to the Free Software
- *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
  */
 
 #ifndef __GRUTABLES_H__
@@ -320,10 +307,8 @@
 
 struct gru_mm_struct {
 	struct mmu_notifier	ms_notifier;
-	atomic_t		ms_refcnt;
 	spinlock_t		ms_asid_lock;	/* protects ASID assignment */
 	atomic_t		ms_range_active;/* num range_invals active */
-	char			ms_released;
 	wait_queue_head_t	ms_wait_queue;
 	DECLARE_BITMAP(ms_asidmap, GRU_MAX_GRUS);
 	struct gru_mm_tracker	ms_asids[GRU_MAX_GRUS];
diff --git a/drivers/misc/sgi-gru/grutlbpurge.c b/drivers/misc/sgi-gru/grutlbpurge.c
index be28f05..10921cd 100644
--- a/drivers/misc/sgi-gru/grutlbpurge.c
+++ b/drivers/misc/sgi-gru/grutlbpurge.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
 /*
  * SN Platform GRU Driver
  *
@@ -9,20 +10,6 @@
  * from the GRU driver.
  *
  *  Copyright (c) 2008 Silicon Graphics, Inc.  All Rights Reserved.
- *
- *  This program is free software; you can redistribute it and/or modify
- *  it under the terms of the GNU General Public License as published by
- *  the Free Software Foundation; either version 2 of the License, or
- *  (at your option) any later version.
- *
- *  This program is distributed in the hope that it will be useful,
- *  but WITHOUT ANY WARRANTY; without even the implied warranty of
- *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- *  GNU General Public License for more details.
- *
- *  You should have received a copy of the GNU General Public License
- *  along with this program; if not, write to the Free Software
- *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
  */
 
 #include <linux/kernel.h>
@@ -220,9 +207,7 @@
  * MMUOPS notifier callout functions
  */
 static int gru_invalidate_range_start(struct mmu_notifier *mn,
-				       struct mm_struct *mm,
-				       unsigned long start, unsigned long end,
-				       bool blockable)
+			const struct mmu_notifier_range *range)
 {
 	struct gru_mm_struct *gms = container_of(mn, struct gru_mm_struct,
 						 ms_notifier);
@@ -230,15 +215,14 @@
 	STAT(mmu_invalidate_range);
 	atomic_inc(&gms->ms_range_active);
 	gru_dbg(grudev, "gms %p, start 0x%lx, end 0x%lx, act %d\n", gms,
-		start, end, atomic_read(&gms->ms_range_active));
-	gru_flush_tlb_range(gms, start, end - start);
+		range->start, range->end, atomic_read(&gms->ms_range_active));
+	gru_flush_tlb_range(gms, range->start, range->end - range->start);
 
 	return 0;
 }
 
 static void gru_invalidate_range_end(struct mmu_notifier *mn,
-				     struct mm_struct *mm, unsigned long start,
-				     unsigned long end)
+			const struct mmu_notifier_range *range)
 {
 	struct gru_mm_struct *gms = container_of(mn, struct gru_mm_struct,
 						 ms_notifier);
@@ -247,87 +231,51 @@
 	(void)atomic_dec_and_test(&gms->ms_range_active);
 
 	wake_up_all(&gms->ms_wait_queue);
-	gru_dbg(grudev, "gms %p, start 0x%lx, end 0x%lx\n", gms, start, end);
+	gru_dbg(grudev, "gms %p, start 0x%lx, end 0x%lx\n",
+		gms, range->start, range->end);
 }
 
-static void gru_release(struct mmu_notifier *mn, struct mm_struct *mm)
+static struct mmu_notifier *gru_alloc_notifier(struct mm_struct *mm)
 {
-	struct gru_mm_struct *gms = container_of(mn, struct gru_mm_struct,
-						 ms_notifier);
+	struct gru_mm_struct *gms;
 
-	gms->ms_released = 1;
-	gru_dbg(grudev, "gms %p\n", gms);
+	gms = kzalloc(sizeof(*gms), GFP_KERNEL);
+	if (!gms)
+		return ERR_PTR(-ENOMEM);
+	STAT(gms_alloc);
+	spin_lock_init(&gms->ms_asid_lock);
+	init_waitqueue_head(&gms->ms_wait_queue);
+
+	return &gms->ms_notifier;
 }
 
+static void gru_free_notifier(struct mmu_notifier *mn)
+{
+	kfree(container_of(mn, struct gru_mm_struct, ms_notifier));
+	STAT(gms_free);
+}
 
 static const struct mmu_notifier_ops gru_mmuops = {
-	.flags			= MMU_INVALIDATE_DOES_NOT_BLOCK,
 	.invalidate_range_start	= gru_invalidate_range_start,
 	.invalidate_range_end	= gru_invalidate_range_end,
-	.release		= gru_release,
+	.alloc_notifier		= gru_alloc_notifier,
+	.free_notifier		= gru_free_notifier,
 };
 
-/* Move this to the basic mmu_notifier file. But for now... */
-static struct mmu_notifier *mmu_find_ops(struct mm_struct *mm,
-			const struct mmu_notifier_ops *ops)
-{
-	struct mmu_notifier *mn, *gru_mn = NULL;
-
-	if (mm->mmu_notifier_mm) {
-		rcu_read_lock();
-		hlist_for_each_entry_rcu(mn, &mm->mmu_notifier_mm->list,
-					 hlist)
-		    if (mn->ops == ops) {
-			gru_mn = mn;
-			break;
-		}
-		rcu_read_unlock();
-	}
-	return gru_mn;
-}
-
 struct gru_mm_struct *gru_register_mmu_notifier(void)
 {
-	struct gru_mm_struct *gms;
 	struct mmu_notifier *mn;
-	int err;
 
-	mn = mmu_find_ops(current->mm, &gru_mmuops);
-	if (mn) {
-		gms = container_of(mn, struct gru_mm_struct, ms_notifier);
-		atomic_inc(&gms->ms_refcnt);
-	} else {
-		gms = kzalloc(sizeof(*gms), GFP_KERNEL);
-		if (!gms)
-			return ERR_PTR(-ENOMEM);
-		STAT(gms_alloc);
-		spin_lock_init(&gms->ms_asid_lock);
-		gms->ms_notifier.ops = &gru_mmuops;
-		atomic_set(&gms->ms_refcnt, 1);
-		init_waitqueue_head(&gms->ms_wait_queue);
-		err = __mmu_notifier_register(&gms->ms_notifier, current->mm);
-		if (err)
-			goto error;
-	}
-	if (gms)
-		gru_dbg(grudev, "gms %p, refcnt %d\n", gms,
-			atomic_read(&gms->ms_refcnt));
-	return gms;
-error:
-	kfree(gms);
-	return ERR_PTR(err);
+	mn = mmu_notifier_get_locked(&gru_mmuops, current->mm);
+	if (IS_ERR(mn))
+		return ERR_CAST(mn);
+
+	return container_of(mn, struct gru_mm_struct, ms_notifier);
 }
 
 void gru_drop_mmu_notifier(struct gru_mm_struct *gms)
 {
-	gru_dbg(grudev, "gms %p, refcnt %d, released %d\n", gms,
-		atomic_read(&gms->ms_refcnt), gms->ms_released);
-	if (atomic_dec_return(&gms->ms_refcnt) == 0) {
-		if (!gms->ms_released)
-			mmu_notifier_unregister(&gms->ms_notifier, current->mm);
-		kfree(gms);
-		STAT(gms_free);
-	}
+	mmu_notifier_put(&gms->ms_notifier);
 }
 
 /*