[S390] Use alternative user-copy operations for new hardware.

This introduces new user-copy operations which are optimized for
copying more than 256 Bytes on new hardware.

Signed-off-by: Gerald Schaefer <geraldsc@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

diff --git a/arch/s390/kernel/head64.S b/arch/s390/kernel/head64.S
index 1ebaa33..a8bdd96 100644 (file)
--- a/arch/s390/kernel/head64.S
+++ b/arch/s390/kernel/head64.S
@@ -250,6 +250,19 @@ startup_continue:
        oi      7(%r12),0x80            # set IDTE flag
 0:
 
+#
+# find out if we have the MVCOS instruction
+#
+       la      %r1,0f-.LPG1(%r13)      # set program check address
+       stg     %r1,__LC_PGM_NEW_PSW+8
+       .short  0xc800                  # mvcos 0(%r0),0(%r0),%r0
+       .short  0x0000
+       .short  0x0000
+0:     tm      0x8f,0x13               # special-operation exception?
+       bno     1f-.LPG1(%r13)          # if yes, MVCOS is present
+       oi      6(%r12),2               # set MVCOS flag
+1:
+
         lpswe .Lentry-.LPG1(13)         # jump to _stext in primary-space,
                                         # virtual and never return ...
         .align 16

diff --git a/arch/s390/kernel/setup.c b/arch/s390/kernel/setup.c
index e229af5..e3d9325 100644 (file)
--- a/arch/s390/kernel/setup.c
+++ b/arch/s390/kernel/setup.c
@@ -647,7 +647,11 @@ setup_arch(char **cmdline_p)
 
        memory_end = memory_size;
 
-       memcpy(&uaccess, &uaccess_std, sizeof(uaccess));
+       if (MACHINE_HAS_MVCOS)
+               memcpy(&uaccess, &uaccess_mvcos, sizeof(uaccess));
+       else
+               memcpy(&uaccess, &uaccess_std, sizeof(uaccess));
+
        parse_early_param();
 
 #ifndef CONFIG_64BIT

diff --git a/arch/s390/lib/Makefile b/arch/s390/lib/Makefile
index 96c8242..c42ffed 100644 (file)
--- a/arch/s390/lib/Makefile
+++ b/arch/s390/lib/Makefile
@@ -5,4 +5,5 @@
 EXTRA_AFLAGS := -traditional
 
 lib-y += delay.o string.o uaccess_std.o
+lib-$(CONFIG_64BIT) += uaccess_mvcos.o
 lib-$(CONFIG_SMP) += spinlock.o

diff --git a/arch/s390/lib/uaccess_mvcos.c b/arch/s390/lib/uaccess_mvcos.c
new file mode 100644 (file)
index 0000000..86c96d6
--- /dev/null
+++ b/arch/s390/lib/uaccess_mvcos.c
@@ -0,0 +1,156 @@
+/*
+ *  arch/s390/lib/uaccess_mvcos.c
+ *
+ *  Optimized user space space access functions based on mvcos.
+ *
+ *    Copyright (C) IBM Corp. 2006
+ *    Author(s): Martin Schwidefsky (schwidefsky@de.ibm.com),
+ *              Gerald Schaefer (gerald.schaefer@de.ibm.com)
+ */
+
+#include <linux/errno.h>
+#include <linux/mm.h>
+#include <asm/uaccess.h>
+#include <asm/futex.h>
+
+#ifndef __s390x__
+#define AHI    "ahi"
+#define ALR    "alr"
+#define CLR    "clr"
+#define LHI    "lhi"
+#define SLR    "slr"
+#else
+#define AHI    "aghi"
+#define ALR    "algr"
+#define CLR    "clgr"
+#define LHI    "lghi"
+#define SLR    "slgr"
+#endif
+
+size_t copy_from_user_mvcos(size_t size, const void __user *ptr, void *x)
+{
+       register unsigned long reg0 asm("0") = 0x81UL;
+       unsigned long tmp1, tmp2;
+
+       tmp1 = -4096UL;
+       asm volatile(
+               "0: .insn ss,0xc80000000000,0(%0,%2),0(%1),0\n"
+               "   jz    4f\n"
+               "1:"ALR"  %0,%3\n"
+               "  "SLR"  %1,%3\n"
+               "  "SLR"  %2,%3\n"
+               "   j     0b\n"
+               "2: la    %4,4095(%1)\n"/* %4 = ptr + 4095 */
+               "   nr    %4,%3\n"      /* %4 = (ptr + 4095) & -4096 */
+               "  "SLR"  %4,%1\n"
+               "  "CLR"  %0,%4\n"      /* copy crosses next page boundary? */
+               "   jnh   5f\n"
+               "3: .insn ss,0xc80000000000,0(%4,%2),0(%1),0\n"
+               "  "SLR"  %0,%4\n"
+               "   j     5f\n"
+               "4:"SLR"  %0,%0\n"
+               "5: \n"
+               EX_TABLE(0b,2b) EX_TABLE(3b,5b)
+               : "+a" (size), "+a" (ptr), "+a" (x), "+a" (tmp1), "=a" (tmp2)
+               : "d" (reg0) : "cc", "memory");
+       return size;
+}
+
+size_t copy_to_user_mvcos(size_t size, void __user *ptr, const void *x)
+{
+       register unsigned long reg0 asm("0") = 0x810000UL;
+       unsigned long tmp1, tmp2;
+
+       tmp1 = -4096UL;
+       asm volatile(
+               "0: .insn ss,0xc80000000000,0(%0,%1),0(%2),0\n"
+               "   jz    4f\n"
+               "1:"ALR"  %0,%3\n"
+               "  "SLR"  %1,%3\n"
+               "  "SLR"  %2,%3\n"
+               "   j     0b\n"
+               "2: la    %4,4095(%1)\n"/* %4 = ptr + 4095 */
+               "   nr    %4,%3\n"      /* %4 = (ptr + 4095) & -4096 */
+               "  "SLR"  %4,%1\n"
+               "  "CLR"  %0,%4\n"      /* copy crosses next page boundary? */
+               "   jnh   5f\n"
+               "3: .insn ss,0xc80000000000,0(%4,%1),0(%2),0\n"
+               "  "SLR"  %0,%4\n"
+               "   j     5f\n"
+               "4:"SLR"  %0,%0\n"
+               "5: \n"
+               EX_TABLE(0b,2b) EX_TABLE(3b,5b)
+               : "+a" (size), "+a" (ptr), "+a" (x), "+a" (tmp1), "=a" (tmp2)
+               : "d" (reg0) : "cc", "memory");
+       return size;
+}
+
+size_t copy_in_user_mvcos(size_t size, void __user *to, const void __user *from)
+{
+       register unsigned long reg0 asm("0") = 0x810081UL;
+       unsigned long tmp1, tmp2;
+
+       tmp1 = -4096UL;
+       /* FIXME: copy with reduced length. */
+       asm volatile(
+               "0: .insn ss,0xc80000000000,0(%0,%1),0(%2),0\n"
+               "   jz    2f\n"
+               "1:"ALR"  %0,%3\n"
+               "  "SLR"  %1,%3\n"
+               "  "SLR"  %2,%3\n"
+               "   j     0b\n"
+               "2:"SLR"  %0,%0\n"
+               "3: \n"
+               EX_TABLE(0b,3b)
+               : "+a" (size), "+a" (to), "+a" (from), "+a" (tmp1), "=a" (tmp2)
+               : "d" (reg0) : "cc", "memory");
+       return size;
+}
+
+size_t clear_user_mvcos(size_t size, void __user *to)
+{
+       register unsigned long reg0 asm("0") = 0x810000UL;
+       unsigned long tmp1, tmp2;
+
+       tmp1 = -4096UL;
+       asm volatile(
+               "0: .insn ss,0xc80000000000,0(%0,%1),0(%4),0\n"
+               "   jz    4f\n"
+               "1:"ALR"  %0,%2\n"
+               "  "SLR"  %1,%2\n"
+               "   j     0b\n"
+               "2: la    %3,4095(%1)\n"/* %4 = to + 4095 */
+               "   nr    %3,%2\n"      /* %4 = (to + 4095) & -4096 */
+               "  "SLR"  %3,%1\n"
+               "  "CLR"  %0,%3\n"      /* copy crosses next page boundary? */
+               "   jnh   5f\n"
+               "3: .insn ss,0xc80000000000,0(%3,%1),0(%4),0\n"
+               "  "SLR"  %0,%3\n"
+               "   j     5f\n"
+               "4:"SLR"  %0,%0\n"
+               "5: \n"
+               EX_TABLE(0b,2b) EX_TABLE(3b,5b)
+               : "+a" (size), "+a" (to), "+a" (tmp1), "=a" (tmp2)
+               : "a" (empty_zero_page), "d" (reg0) : "cc", "memory");
+       return size;
+}
+
+extern size_t copy_from_user_std_small(size_t, const void __user *, void *);
+extern size_t copy_to_user_std_small(size_t, void __user *, const void *);
+extern size_t strnlen_user_std(size_t, const char __user *);
+extern size_t strncpy_from_user_std(size_t, const char __user *, char *);
+extern int futex_atomic_op(int, int __user *, int, int *);
+extern int futex_atomic_cmpxchg(int __user *, int, int);
+
+struct uaccess_ops uaccess_mvcos = {
+       .copy_from_user = copy_from_user_mvcos,
+       .copy_from_user_small = copy_from_user_std_small,
+       .copy_to_user = copy_to_user_mvcos,
+       .copy_to_user_small = copy_to_user_std_small,
+       .copy_in_user = copy_in_user_mvcos,
+       .clear_user = clear_user_mvcos,
+       .strnlen_user = strnlen_user_std,
+       .strncpy_from_user = strncpy_from_user_std,
+       .futex_atomic_op = futex_atomic_op,
+       .futex_atomic_cmpxchg = futex_atomic_cmpxchg,
+};

diff --git a/include/asm-s390/setup.h b/include/asm-s390/setup.h
index 00c03e4..f195973 100644 (file)
--- a/include/asm-s390/setup.h
+++ b/include/asm-s390/setup.h
@@ -44,10 +44,12 @@ extern unsigned long machine_flags;
 #define MACHINE_HAS_IEEE       (machine_flags & 2)
 #define MACHINE_HAS_CSP                (machine_flags & 8)
 #define MACHINE_HAS_DIAG44     (1)
+#define MACHINE_HAS_MVCOS      (0)
 #else /* __s390x__ */
 #define MACHINE_HAS_IEEE       (1)
 #define MACHINE_HAS_CSP                (1)
 #define MACHINE_HAS_DIAG44     (machine_flags & 32)
+#define MACHINE_HAS_MVCOS      (machine_flags & 512)
 #endif /* __s390x__ */
 
 

diff --git a/include/asm-s390/uaccess.h b/include/asm-s390/uaccess.h
index 39a2716..e2047b0 100644 (file)
--- a/include/asm-s390/uaccess.h
+++ b/include/asm-s390/uaccess.h
@@ -100,6 +100,7 @@ struct uaccess_ops {
 
 extern struct uaccess_ops uaccess;
 extern struct uaccess_ops uaccess_std;
+extern struct uaccess_ops uaccess_mvcos;
 
 static inline int __put_user_fn(size_t size, void __user *ptr, void *x)
 {