[PATCH 3/7] m68k: remove the inline copy_{from,to}_user variants

Christoph Hellwig
2021-07-09T07:02:08Z

Small access already use get_user/put_user so move the whole larger user
copy machinery out of line.

This saves almost 10k of .text for a defconfig build:

text data bss dec hex filename
4019751 1344434 170104 5534289 547251 vmlinux.pre
4015417 1338962 170104 5524483 544c03 vmlinux.post

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
arch/m68k/include/asm/uaccess.h | 201 +-------------------------------
arch/m68k/lib/uaccess.c | 12 +-
2 files changed, 10 insertions(+), 203 deletions(-)

diff --git a/arch/m68k/include/asm/uaccess.h b/arch/m68k/include/asm/uaccess.h
index 01334a9658c4..96aae4d4656b 100644
--- a/arch/m68k/include/asm/uaccess.h
+++ b/arch/m68k/include/asm/uaccess.h
@@ -181,203 +181,10 @@ asm volatile ("\n" \
})
#define get_user(x, ptr) __get_user(x, ptr)

-unsigned long __generic_copy_from_user(void *to, const void __user *from, unsigned long n);
-unsigned long __generic_copy_to_user(void __user *to, const void *from, unsigned long n);
-
-#define __suffix0
-#define __suffix1 b
-#define __suffix2 w
-#define __suffix4 l
-
-#define ____constant_copy_from_user_asm(res, to, from, tmp, n1, n2, n3, s1, s2, s3)\
- asm volatile ("\n" \
- "1: "MOVES"."#s1" (%2)+,%3\n" \
- " move."#s1" %3,(%1)+\n" \
- " .ifnc \""#s2"\",\"\"\n" \
- "2: "MOVES"."#s2" (%2)+,%3\n" \
- " move."#s2" %3,(%1)+\n" \
- " .ifnc \""#s3"\",\"\"\n" \
- "3: "MOVES"."#s3" (%2)+,%3\n" \
- " move."#s3" %3,(%1)+\n" \
- " .endif\n" \
- " .endif\n" \
- "4:\n" \
- " .section __ex_table,\"a\"\n" \
- " .align 4\n" \
- " .long 1b,10f\n" \
- " .ifnc \""#s2"\",\"\"\n" \
- " .long 2b,20f\n" \
- " .ifnc \""#s3"\",\"\"\n" \
- " .long 3b,30f\n" \
- " .endif\n" \
- " .endif\n" \
- " .previous\n" \
- "\n" \
- " .section .fixup,\"ax\"\n" \
- " .even\n" \
- "10: addq.l #"#n1",%0\n" \
- " .ifnc \""#s2"\",\"\"\n" \
- "20: addq.l #"#n2",%0\n" \
- " .ifnc \""#s3"\",\"\"\n" \
- "30: addq.l #"#n3",%0\n" \
- " .endif\n" \
- " .endif\n" \
- " jra 4b\n" \
- " .previous\n" \
- : "+d" (res), "+&a" (to), "+a" (from), "=&d" (tmp) \
- : : "memory")
-
-#define ___constant_copy_from_user_asm(res, to, from, tmp, n1, n2, n3, s1, s2, s3)\
- ____constant_copy_from_user_asm(res, to, from, tmp, n1, n2, n3, s1, s2, s3)
-#define __constant_copy_from_user_asm(res, to, from, tmp, n1, n2, n3) \
- ___constant_copy_from_user_asm(res, to, from, tmp, n1, n2, n3, \
- __suffix##n1, __suffix##n2, __suffix##n3)
-
-static __always_inline unsigned long
-__constant_copy_from_user(void *to, const void __user *from, unsigned long n)
-{
- unsigned long res = 0, tmp;
-
- switch (n) {
- case 1:
- __constant_copy_from_user_asm(res, to, from, tmp, 1, 0, 0);
- break;
- case 2:
- __constant_copy_from_user_asm(res, to, from, tmp, 2, 0, 0);
- break;
- case 3:
- __constant_copy_from_user_asm(res, to, from, tmp, 2, 1, 0);
- break;
- case 4:
- __constant_copy_from_user_asm(res, to, from, tmp, 4, 0, 0);
- break;
- case 5:
- __constant_copy_from_user_asm(res, to, from, tmp, 4, 1, 0);
- break;
- case 6:
- __constant_copy_from_user_asm(res, to, from, tmp, 4, 2, 0);
- break;
- case 7:
- __constant_copy_from_user_asm(res, to, from, tmp, 4, 2, 1);
- break;
- case 8:
- __constant_copy_from_user_asm(res, to, from, tmp, 4, 4, 0);
- break;
- case 9:
- __constant_copy_from_user_asm(res, to, from, tmp, 4, 4, 1);
- break;
- case 10:
- __constant_copy_from_user_asm(res, to, from, tmp, 4, 4, 2);
- break;
- case 12:
- __constant_copy_from_user_asm(res, to, from, tmp, 4, 4, 4);
- break;
- default:
- /* we limit the inlined version to 3 moves */
- return __generic_copy_from_user(to, from, n);
- }
-
- return res;
-}
-
-#define __constant_copy_to_user_asm(res, to, from, tmp, n, s1, s2, s3) \
- asm volatile ("\n" \
- " move."#s1" (%2)+,%3\n" \
- "11: "MOVES"."#s1" %3,(%1)+\n" \
- "12: move."#s2" (%2)+,%3\n" \
- "21: "MOVES"."#s2" %3,(%1)+\n" \
- "22:\n" \
- " .ifnc \""#s3"\",\"\"\n" \
- " move."#s3" (%2)+,%3\n" \
- "31: "MOVES"."#s3" %3,(%1)+\n" \
- "32:\n" \
- " .endif\n" \
- "4:\n" \
- "\n" \
- " .section __ex_table,\"a\"\n" \
- " .align 4\n" \
- " .long 11b,5f\n" \
- " .long 12b,5f\n" \
- " .long 21b,5f\n" \
- " .long 22b,5f\n" \
- " .ifnc \""#s3"\",\"\"\n" \
- " .long 31b,5f\n" \
- " .long 32b,5f\n" \
- " .endif\n" \
- " .previous\n" \
- "\n" \
- " .section .fixup,\"ax\"\n" \
- " .even\n" \
- "5: moveq.l #"#n",%0\n" \
- " jra 4b\n" \
- " .previous\n" \
- : "+d" (res), "+a" (to), "+a" (from), "=&d" (tmp) \
- : : "memory")
-
-static __always_inline unsigned long
-__constant_copy_to_user(void __user *to, const void *from, unsigned long n)
-{
- unsigned long res = 0, tmp;
-
- switch (n) {
- case 1:
- __put_user_asm(res, *(u8 *)from, (u8 __user *)to, b, d, 1);
- break;
- case 2:
- __put_user_asm(res, *(u16 *)from, (u16 __user *)to, w, r, 2);
- break;
- case 3:
- __constant_copy_to_user_asm(res, to, from, tmp, 3, w, b,);
- break;
- case 4:
- __put_user_asm(res, *(u32 *)from, (u32 __user *)to, l, r, 4);
- break;
- case 5:
- __constant_copy_to_user_asm(res, to, from, tmp, 5, l, b,);
- break;
- case 6:
- __constant_copy_to_user_asm(res, to, from, tmp, 6, l, w,);
- break;
- case 7:
- __constant_copy_to_user_asm(res, to, from, tmp, 7, l, w, b);
- break;
- case 8:
- __constant_copy_to_user_asm(res, to, from, tmp, 8, l, l,);
- break;
- case 9:
- __constant_copy_to_user_asm(res, to, from, tmp, 9, l, l, b);
- break;
- case 10:
- __constant_copy_to_user_asm(res, to, from, tmp, 10, l, l, w);
- break;
- case 12:
- __constant_copy_to_user_asm(res, to, from, tmp, 12, l, l, l);
- break;
- default:
- /* limit the inlined version to 3 moves */
- return __generic_copy_to_user(to, from, n);
- }
-
- return res;
-}
-
-static inline unsigned long
-raw_copy_from_user(void *to, const void __user *from, unsigned long n)
-{
- if (__builtin_constant_p(n))
- return __constant_copy_from_user(to, from, n);
- return __generic_copy_from_user(to, from, n);
-}
-
-static inline unsigned long
-raw_copy_to_user(void __user *to, const void *from, unsigned long n)
-{
- if (__builtin_constant_p(n))
- return __constant_copy_to_user(to, from, n);
- return __generic_copy_to_user(to, from, n);
-}
-#define INLINE_COPY_FROM_USER
-#define INLINE_COPY_TO_USER
+unsigned long raw_copy_from_user(void *to, const void __user *from,
+ unsigned long n);
+unsigned long raw_copy_to_user(void __user *to, const void *from,
+ unsigned long n);

#define user_addr_max() \
(uaccess_kernel() ? ~0UL : TASK_SIZE)
diff --git a/arch/m68k/lib/uaccess.c b/arch/m68k/lib/uaccess.c
index 7646e461aa62..56022d06b780 100644
--- a/arch/m68k/lib/uaccess.c
+++ b/arch/m68k/lib/uaccess.c
@@ -7,8 +7,8 @@
#include <linux/module.h>
#include <linux/uaccess.h>

-unsigned long __generic_copy_from_user(void *to, const void __user *from,
- unsigned long n)
+unsigned long raw_copy_from_user(void *to, const void __user *from,
+ unsigned long n)
{
unsigned long tmp, res;

@@ -51,10 +51,10 @@ unsigned long __generic_copy_from_user(void *to, const void __user *from,

return res;
}
-EXPORT_SYMBOL(__generic_copy_from_user);
+EXPORT_SYMBOL(raw_copy_from_user);

-unsigned long __generic_copy_to_user(void __user *to, const void *from,
- unsigned long n)
+unsigned long raw_copy_to_user(void __user *to, const void *from,
+ unsigned long n)
{
unsigned long tmp, res;

@@ -95,7 +95,7 @@ unsigned long __generic_copy_to_user(void __user *to, const void *from,

return res;
}
-EXPORT_SYMBOL(__generic_copy_to_user);
+EXPORT_SYMBOL(raw_copy_to_user);

/*
* Zero Userspace
--
2.30.2