diff options
author | Gerald Schaefer <geraldsc@de.ibm.com> | 2006-12-04 15:40:45 +0100 |
---|---|---|
committer | Martin Schwidefsky <schwidefsky@de.ibm.com> | 2006-12-04 15:40:45 +0100 |
commit | 59f35d53fde3987d071ea1c9bf1c9ba29fcb69fe (patch) | |
tree | 50853c1bf3ad3af080707fb2e6b3722d3d86db9e /arch/s390/lib/uaccess_std.c | |
parent | d57de5a36791cb1b7285649c62f183b0d3505f7d (diff) |
[S390] Add dynamic size check for usercopy functions.
Use a wrapper for copy_to/from_user to chose the best usercopy method.
The mvcos instruction is better for sizes greater than 256 bytes, if
mvcos is not available a page table walk is better for sizes greater
than 1024 bytes. Also removed the redundant copy_to/from_user_std_small
functions.
Signed-off-by: Gerald Schaefer <geraldsc@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Diffstat (limited to 'arch/s390/lib/uaccess_std.c')
-rw-r--r-- | arch/s390/lib/uaccess_std.c | 67 |
1 files changed, 15 insertions, 52 deletions
diff --git a/arch/s390/lib/uaccess_std.c b/arch/s390/lib/uaccess_std.c index f44f0078b354..2d549ed2e113 100644 --- a/arch/s390/lib/uaccess_std.c +++ b/arch/s390/lib/uaccess_std.c @@ -28,6 +28,9 @@ #define SLR "slgr" #endif +extern size_t copy_from_user_pt(size_t n, const void __user *from, void *to); +extern size_t copy_to_user_pt(size_t n, void __user *to, const void *from); + size_t copy_from_user_std(size_t size, const void __user *ptr, void *x) { unsigned long tmp1, tmp2; @@ -69,34 +72,11 @@ size_t copy_from_user_std(size_t size, const void __user *ptr, void *x) return size; } -size_t copy_from_user_std_small(size_t size, const void __user *ptr, void *x) +size_t copy_from_user_std_check(size_t size, const void __user *ptr, void *x) { - unsigned long tmp1, tmp2; - - tmp1 = 0UL; - asm volatile( - "0: mvcp 0(%0,%2),0(%1),%3\n" - " "SLR" %0,%0\n" - " j 5f\n" - "1: la %4,255(%1)\n" /* %4 = ptr + 255 */ - " "LHI" %3,-4096\n" - " nr %4,%3\n" /* %4 = (ptr + 255) & -4096 */ - " "SLR" %4,%1\n" - " "CLR" %0,%4\n" /* copy crosses next page boundary? */ - " jnh 5f\n" - "2: mvcp 0(%4,%2),0(%1),%3\n" - " "SLR" %0,%4\n" - " "ALR" %2,%4\n" - "3:"LHI" %4,-1\n" - " "ALR" %4,%0\n" /* copy remaining size, subtract 1 */ - " bras %3,4f\n" - " xc 0(1,%2),0(%2)\n" - "4: ex %4,0(%3)\n" - "5:\n" - EX_TABLE(0b,1b) EX_TABLE(2b,3b) - : "+a" (size), "+a" (ptr), "+a" (x), "+a" (tmp1), "=a" (tmp2) - : : "cc", "memory"); - return size; + if (size <= 1024) + return copy_from_user_std(size, ptr, x); + return copy_from_user_pt(size, ptr, x); } size_t copy_to_user_std(size_t size, void __user *ptr, const void *x) @@ -130,28 +110,11 @@ size_t copy_to_user_std(size_t size, void __user *ptr, const void *x) return size; } -size_t copy_to_user_std_small(size_t size, void __user *ptr, const void *x) +size_t copy_to_user_std_check(size_t size, void __user *ptr, const void *x) { - unsigned long tmp1, tmp2; - - tmp1 = 0UL; - asm volatile( - "0: mvcs 0(%0,%1),0(%2),%3\n" - " "SLR" %0,%0\n" - " j 3f\n" - "1: la %4,255(%1)\n" /* ptr + 255 */ - " "LHI" %3,-4096\n" - " nr %4,%3\n" /* (ptr + 255) & -4096UL */ - " "SLR" %4,%1\n" - " "CLR" %0,%4\n" /* copy crosses next page boundary? */ - " jnh 3f\n" - "2: mvcs 0(%4,%1),0(%2),%3\n" - " "SLR" %0,%4\n" - "3:\n" - EX_TABLE(0b,1b) EX_TABLE(2b,3b) - : "+a" (size), "+a" (ptr), "+a" (x), "+a" (tmp1), "=a" (tmp2) - : : "cc", "memory"); - return size; + if (size <= 1024) + return copy_to_user_std(size, ptr, x); + return copy_to_user_pt(size, ptr, x); } size_t copy_in_user_std(size_t size, void __user *to, const void __user *from) @@ -343,10 +306,10 @@ int futex_atomic_cmpxchg(int __user *uaddr, int oldval, int newval) } struct uaccess_ops uaccess_std = { - .copy_from_user = copy_from_user_std, - .copy_from_user_small = copy_from_user_std_small, - .copy_to_user = copy_to_user_std, - .copy_to_user_small = copy_to_user_std_small, + .copy_from_user = copy_from_user_std_check, + .copy_from_user_small = copy_from_user_std, + .copy_to_user = copy_to_user_std_check, + .copy_to_user_small = copy_to_user_std, .copy_in_user = copy_in_user_std, .clear_user = clear_user_std, .strnlen_user = strnlen_user_std, |