perf/x86/intel: Rename DMR offcore_rsp attribute to offmodule_rspgrafted

DMR introduces Offmodule Response events in place of the legacy
Offcore Response events, but it still exposes the inherited
offcore_rsp PMU attribute for programming the corresponding MSR data.

Rename the DMR PMU attribute to offmodule_rsp so the sysfs interface
matches the underlying event name and avoids user & tooling confusion.

Signed-off-by: Dapeng Mi <dapeng1.mi@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://patch.msgid.link/20260917015234.981153-12-dapeng1.mi@linux.intel.com

1 files changed, 66 insertions, 0 deletions

diff --git a/fs/nullfs.c b/fs/nullfs.c
new file mode 100644
index 000000000..e06352c7b
--- /dev/null
+++ b/fs/nullfs.c
@@ -0,0 +1,66 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/* Copyright (c) 2026 Christian Brauner <brauner@kernel.org> */
+#include <linux/fs/super_types.h>
+#include <linux/fs_context.h>
+#include <linux/magic.h>
+
+#include "mount.h"
+
+static const struct super_operations nullfs_super_operations = {
+	.statfs	= simple_statfs,
+};
+
+static int nullfs_fs_fill_super(struct super_block *s, struct fs_context *fc)
+{
+	struct inode *inode;
+
+	s->s_maxbytes		= MAX_LFS_FILESIZE;
+	s->s_blocksize		= PAGE_SIZE;
+	s->s_blocksize_bits	= PAGE_SHIFT;
+	s->s_magic		= NULL_FS_MAGIC;
+	s->s_op			= &nullfs_super_operations;
+	s->s_export_op		= NULL;
+	s->s_xattr		= NULL;
+	s->s_time_gran		= 1;
+	s->s_d_flags		= 0;
+
+	inode = new_inode(s);
+	if (!inode)
+		return -ENOMEM;
+
+	/* nullfs is permanently empty... */
+	make_empty_dir_inode(inode);
+	simple_inode_init_ts(inode);
+	inode->i_ino	= 1;
+	/* ... and immutable. */
+	inode->i_flags |= S_IMMUTABLE;
+
+	s->s_root = d_make_root(inode);
+	if (!s->s_root)
+		return -ENOMEM;
+
+	return 0;
+}
+
+static int nullfs_fs_get_tree(struct fs_context *fc)
+{
+	return get_tree_nodev(fc, nullfs_fs_fill_super);
+}
+
+static const struct fs_context_operations nullfs_fs_context_ops = {
+	.get_tree	= nullfs_fs_get_tree,
+};
+
+static int nullfs_init_fs_context(struct fs_context *fc)
+{
+	fc->ops		= &nullfs_fs_context_ops;
+	fc->sb_flags	|= SB_NOUSER;
+	fc->s_iflags	|= SB_I_NOEXEC | SB_I_NODEV;
+	return 0;
+}
+
+struct file_system_type nullfs_fs_type = {
+	.name			= "nullfs",
+	.init_fs_context	= nullfs_init_fs_context,
+	.kill_sb		= kill_anon_super,
+};