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authorNicolas Pitre <nico@cam.org>2005-11-01 14:52:24 -0500
committerRussell King <rmk+kernel@arm.linux.org.uk>2005-11-01 14:52:24 -0500
commitfadab0943d1c5b652a66858bb99b204fedaad96b (patch)
treeae8f83cd0b6c97ee2120688f3e4f4cfd431b0c3e /arch/arm/lib
parent7549423000fc38d39a8b81c601dea0332c113a42 (diff)
[ARM] 2948/1: new preemption safe copy_{to|from}_user implementation
Patch from Nicolas Pitre This patch provides a preemption safe implementation of copy_to_user and copy_from_user based on the copy template also used for memcpy. It is enabled unconditionally when CONFIG_PREEMPT=y. Otherwise if the configured architecture is not ARMv3 then it is enabled as well as it gives better performances at least on StrongARM and XScale cores. If ARMv3 is not too affected or if it doesn't matter too much then uaccess.S could be removed altogether. Signed-off-by: Nicolas Pitre <nico@cam.org> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Diffstat (limited to 'arch/arm/lib')
-rw-r--r--arch/arm/lib/Makefile16
-rw-r--r--arch/arm/lib/copy_from_user.S101
-rw-r--r--arch/arm/lib/copy_to_user.S101
3 files changed, 216 insertions, 2 deletions
diff --git a/arch/arm/lib/Makefile b/arch/arm/lib/Makefile
index 8f9770f1af19..391f3ab3ff32 100644
--- a/arch/arm/lib/Makefile
+++ b/arch/arm/lib/Makefile
@@ -9,13 +9,25 @@ lib-y := backtrace.o changebit.o csumipv6.o csumpartial.o \
9 copy_page.o delay.o findbit.o memchr.o memcpy.o \ 9 copy_page.o delay.o findbit.o memchr.o memcpy.o \
10 memmove.o memset.o memzero.o setbit.o \ 10 memmove.o memset.o memzero.o setbit.o \
11 strncpy_from_user.o strnlen_user.o \ 11 strncpy_from_user.o strnlen_user.o \
12 strchr.o strrchr.o testchangebit.o \ 12 strchr.o strrchr.o \
13 testclearbit.o testsetbit.o uaccess.o \ 13 testchangebit.o testclearbit.o testsetbit.o \
14 getuser.o putuser.o clear_user.o \ 14 getuser.o putuser.o clear_user.o \
15 ashldi3.o ashrdi3.o lshrdi3.o muldi3.o \ 15 ashldi3.o ashrdi3.o lshrdi3.o muldi3.o \
16 ucmpdi2.o lib1funcs.o div64.o sha1.o \ 16 ucmpdi2.o lib1funcs.o div64.o sha1.o \
17 io-readsb.o io-writesb.o io-readsl.o io-writesl.o 17 io-readsb.o io-writesb.o io-readsl.o io-writesl.o
18 18
19# the code in uaccess.S is not preemption safe and
20# probably faster on ARMv3 only
21ifeq ($CONFIG_PREEMPT,y)
22 lib-y += copy_from_user.o copy_to_user.o
23else
24ifneq ($(CONFIG_CPU_32v3),y)
25 lib-y += copy_from_user.o copy_to_user.o
26else
27 lib-y += uaccess.o
28endif
29endif
30
19ifeq ($(CONFIG_CPU_32v3),y) 31ifeq ($(CONFIG_CPU_32v3),y)
20 lib-y += io-readsw-armv3.o io-writesw-armv3.o 32 lib-y += io-readsw-armv3.o io-writesw-armv3.o
21else 33else
diff --git a/arch/arm/lib/copy_from_user.S b/arch/arm/lib/copy_from_user.S
new file mode 100644
index 000000000000..7497393a0e81
--- /dev/null
+++ b/arch/arm/lib/copy_from_user.S
@@ -0,0 +1,101 @@
1/*
2 * linux/arch/arm/lib/copy_from_user.S
3 *
4 * Author: Nicolas Pitre
5 * Created: Sep 29, 2005
6 * Copyright: MontaVista Software, Inc.
7 *
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License version 2 as
10 * published by the Free Software Foundation.
11 */
12
13#include <linux/linkage.h>
14#include <asm/assembler.h>
15
16/*
17 * Prototype:
18 *
19 * size_t __arch_copy_from_user(void *to, const void *from, size_t n)
20 *
21 * Purpose:
22 *
23 * copy a block to kernel memory from user memory
24 *
25 * Params:
26 *
27 * to = kernel memory
28 * from = user memory
29 * n = number of bytes to copy
30 *
31 * Return value:
32 *
33 * Number of bytes NOT copied.
34 */
35
36 .macro ldr1w ptr reg abort
37100: ldrt \reg, [\ptr], #4
38 .section __ex_table, "a"
39 .long 100b, \abort
40 .previous
41 .endm
42
43 .macro ldr4w ptr reg1 reg2 reg3 reg4 abort
44 ldr1w \ptr, \reg1, \abort
45 ldr1w \ptr, \reg2, \abort
46 ldr1w \ptr, \reg3, \abort
47 ldr1w \ptr, \reg4, \abort
48 .endm
49
50 .macro ldr8w ptr reg1 reg2 reg3 reg4 reg5 reg6 reg7 reg8 abort
51 ldr4w \ptr, \reg1, \reg2, \reg3, \reg4, \abort
52 ldr4w \ptr, \reg5, \reg6, \reg7, \reg8, \abort
53 .endm
54
55 .macro ldr1b ptr reg cond=al abort
56100: ldr\cond\()bt \reg, [\ptr], #1
57 .section __ex_table, "a"
58 .long 100b, \abort
59 .previous
60 .endm
61
62 .macro str1w ptr reg abort
63 str \reg, [\ptr], #4
64 .endm
65
66 .macro str8w ptr reg1 reg2 reg3 reg4 reg5 reg6 reg7 reg8 abort
67 stmia \ptr!, {\reg1, \reg2, \reg3, \reg4, \reg5, \reg6, \reg7, \reg8}
68 .endm
69
70 .macro str1b ptr reg cond=al abort
71 str\cond\()b \reg, [\ptr], #1
72 .endm
73
74 .macro enter reg1 reg2
75 mov r3, #0
76 stmdb sp!, {r0, r2, r3, \reg1, \reg2}
77 .endm
78
79 .macro exit reg1 reg2
80 add sp, sp, #8
81 ldmfd sp!, {r0, \reg1, \reg2}
82 .endm
83
84 .text
85
86ENTRY(__arch_copy_from_user)
87
88#include "copy_template.S"
89
90 .section .fixup,"ax"
91 .align 0
92 copy_abort_preamble
93 ldmfd sp!, {r1, r2}
94 sub r3, r0, r1
95 rsb r1, r3, r2
96 str r1, [sp]
97 bl __memzero
98 ldr r0, [sp], #4
99 copy_abort_end
100 .previous
101
diff --git a/arch/arm/lib/copy_to_user.S b/arch/arm/lib/copy_to_user.S
new file mode 100644
index 000000000000..4a6d8ea14022
--- /dev/null
+++ b/arch/arm/lib/copy_to_user.S
@@ -0,0 +1,101 @@
1/*
2 * linux/arch/arm/lib/copy_to_user.S
3 *
4 * Author: Nicolas Pitre
5 * Created: Sep 29, 2005
6 * Copyright: MontaVista Software, Inc.
7 *
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License version 2 as
10 * published by the Free Software Foundation.
11 */
12
13#include <linux/linkage.h>
14#include <asm/assembler.h>
15
16/*
17 * Prototype:
18 *
19 * size_t __arch_copy_to_user(void *to, const void *from, size_t n)
20 *
21 * Purpose:
22 *
23 * copy a block to user memory from kernel memory
24 *
25 * Params:
26 *
27 * to = user memory
28 * from = kernel memory
29 * n = number of bytes to copy
30 *
31 * Return value:
32 *
33 * Number of bytes NOT copied.
34 */
35
36 .macro ldr1w ptr reg abort
37 ldr \reg, [\ptr], #4
38 .endm
39
40 .macro ldr4w ptr reg1 reg2 reg3 reg4 abort
41 ldmia \ptr!, {\reg1, \reg2, \reg3, \reg4}
42 .endm
43
44 .macro ldr8w ptr reg1 reg2 reg3 reg4 reg5 reg6 reg7 reg8 abort
45 ldmia \ptr!, {\reg1, \reg2, \reg3, \reg4, \reg5, \reg6, \reg7, \reg8}
46 .endm
47
48 .macro ldr1b ptr reg cond=al abort
49 ldr\cond\()b \reg, [\ptr], #1
50 .endm
51
52 .macro str1w ptr reg abort
53100: strt \reg, [\ptr], #4
54 .section __ex_table, "a"
55 .long 100b, \abort
56 .previous
57 .endm
58
59 .macro str8w ptr reg1 reg2 reg3 reg4 reg5 reg6 reg7 reg8 abort
60 str1w \ptr, \reg1, \abort
61 str1w \ptr, \reg2, \abort
62 str1w \ptr, \reg3, \abort
63 str1w \ptr, \reg4, \abort
64 str1w \ptr, \reg5, \abort
65 str1w \ptr, \reg6, \abort
66 str1w \ptr, \reg7, \abort
67 str1w \ptr, \reg8, \abort
68 .endm
69
70 .macro str1b ptr reg cond=al abort
71100: str\cond\()bt \reg, [\ptr], #1
72 .section __ex_table, "a"
73 .long 100b, \abort
74 .previous
75 .endm
76
77 .macro enter reg1 reg2
78 mov r3, #0
79 stmdb sp!, {r0, r2, r3, \reg1, \reg2}
80 .endm
81
82 .macro exit reg1 reg2
83 add sp, sp, #8
84 ldmfd sp!, {r0, \reg1, \reg2}
85 .endm
86
87 .text
88
89ENTRY(__arch_copy_to_user)
90
91#include "copy_template.S"
92
93 .section .fixup,"ax"
94 .align 0
95 copy_abort_preamble
96 ldmfd sp!, {r1, r2, r3}
97 sub r0, r0, r1
98 rsb r0, r0, r2
99 copy_abort_end
100 .previous
101