Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
runtime constants: add default dummy infrastructure
This adds the initial dummy support for 'runtime constants' for when
an architecture doesn't actually support an implementation of fixing
up said runtime constants.
This ends up being the fallback to just using the variables as regular
__ro_after_init variables, and changes the dcache d_hash() function to
use this model.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
+34
-1
+10
-1
fs/dcache.c
+10
-1
fs/dcache.c
···
35
35
#include "internal.h"
36
36
#include "mount.h"
37
37
38
+
#include <asm/runtime-const.h>
39
+
38
40
/*
39
41
* Usage:
40
42
* dcache->d_inode->i_lock protects:
···
104
102
105
103
static inline struct hlist_bl_head *d_hash(unsigned long hashlen)
106
104
{
107
-
return dentry_hashtable + ((u32)hashlen >> d_hash_shift);
105
+
return runtime_const_ptr(dentry_hashtable) +
106
+
runtime_const_shift_right_32(hashlen, d_hash_shift);
108
107
}
109
108
110
109
#define IN_LOOKUP_SHIFT 10
···
3132
3129
0,
3133
3130
0);
3134
3131
d_hash_shift = 32 - d_hash_shift;
3132
+
3133
+
runtime_const_init(shift, d_hash_shift);
3134
+
runtime_const_init(ptr, dentry_hashtable);
3135
3135
}
3136
3136
3137
3137
static void __init dcache_init(void)
···
3163
3157
0,
3164
3158
0);
3165
3159
d_hash_shift = 32 - d_hash_shift;
3160
+
3161
+
runtime_const_init(shift, d_hash_shift);
3162
+
runtime_const_init(ptr, dentry_hashtable);
3166
3163
}
3167
3164
3168
3165
/* SLAB cache for __getname() consumers */
+1
include/asm-generic/Kbuild
+1
include/asm-generic/Kbuild
+15
include/asm-generic/runtime-const.h
+15
include/asm-generic/runtime-const.h
···
1
+
/* SPDX-License-Identifier: GPL-2.0 */
2
+
#ifndef _ASM_RUNTIME_CONST_H
3
+
#define _ASM_RUNTIME_CONST_H
4
+
5
+
/*
6
+
* This is the fallback for when the architecture doesn't
7
+
* support the runtime const operations.
8
+
*
9
+
* We just use the actual symbols as-is.
10
+
*/
11
+
#define runtime_const_ptr(sym) (sym)
12
+
#define runtime_const_shift_right_32(val, sym) ((u32)(val)>>(sym))
13
+
#define runtime_const_init(type,sym) do { } while (0)
14
+
15
+
#endif
+8
include/asm-generic/vmlinux.lds.h
+8
include/asm-generic/vmlinux.lds.h
···
944
944
#define CON_INITCALL \
945
945
BOUNDED_SECTION_POST_LABEL(.con_initcall.init, __con_initcall, _start, _end)
946
946
947
+
#define RUNTIME_NAME(t,x) runtime_##t##_##x
948
+
949
+
#define RUNTIME_CONST(t,x) \
950
+
. = ALIGN(8); \
951
+
RUNTIME_NAME(t,x) : AT(ADDR(RUNTIME_NAME(t,x)) - LOAD_OFFSET) { \
952
+
*(RUNTIME_NAME(t,x)); \
953
+
}
954
+
947
955
/* Alignment must be consistent with (kunit_suite *) in include/kunit/test.h */
948
956
#define KUNIT_TABLE() \
949
957
. = ALIGN(8); \