s390/uaccess: Merge cmpxchg_user_key() inline assemblies

The inline assemblies for __cmpxchg_user_key1() and __cmpxchg_user_key2()
are identical. Get rid of the duplication and provide a common helper
function.

Suggested-by: Mete Durlu <meted@linux.ibm.com>
Acked-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>

diff --git a/arch/s390/lib/uaccess.c b/arch/s390/lib/uaccess.c
index 750360cce02c0ca020e0025b0abedd476e04a0fd..1a6ba105e071839b580f9acf51c411192503c77a 100644 (file)
--- a/arch/s390/lib/uaccess.c
+++ b/arch/s390/lib/uaccess.c
@@ -150,20 +150,16 @@ EXPORT_SYMBOL(_copy_to_user_key);
 
 #define CMPXCHG_USER_KEY_MAX_LOOPS 128
 
-int __kprobes __cmpxchg_user_key1(unsigned long address, unsigned char *uval,
-                                 unsigned char old, unsigned char new, unsigned long key)
+static nokprobe_inline int __cmpxchg_user_key_small(unsigned long address, unsigned int *uval,
+                                                   unsigned int old, unsigned int new,
+                                                   unsigned int mask, unsigned long key)
 {
-       unsigned int prev, shift, mask, _old, _new;
        unsigned long count;
+       unsigned int prev;
        bool sacf_flag;
        int rc = 0;
 
        skey_regions_initialize();
-       shift = (3 ^ (address & 3)) << 3;
-       address ^= address & 3;
-       _old = (unsigned int)old << shift;
-       _new = (unsigned int)new << shift;
-       mask = ~(0xff << shift);
        sacf_flag = enable_sacf_uaccess();
        asm_inline volatile(
                "20:    spka    0(%[key])\n"
@@ -193,8 +189,8 @@ int __kprobes __cmpxchg_user_key1(unsigned long address, unsigned char *uval,
                : [rc] "+&d" (rc),
                [prev] "=&d" (prev),
                [address] "+Q" (*(int *)address),
-               [tmp] "+&d" (_old),
-               [new] "+&d" (_new),
+               [tmp] "+&d" (old),
+               [new] "+&d" (new),
                [mask] "+&d" (mask),
                [count] "=a" (count)
                : [key] "%[count]" (key << 4),
@@ -202,68 +198,42 @@ int __kprobes __cmpxchg_user_key1(unsigned long address, unsigned char *uval,
                [max_loops] "J" (CMPXCHG_USER_KEY_MAX_LOOPS)
                : "memory", "cc");
        disable_sacf_uaccess(sacf_flag);
-       *uval = prev >> shift;
+       *uval = prev;
        if (!count)
                rc = -EAGAIN;
        return rc;
 }
+
+int __kprobes __cmpxchg_user_key1(unsigned long address, unsigned char *uval,
+                                 unsigned char old, unsigned char new, unsigned long key)
+{
+       unsigned int prev, shift, mask, _old, _new;
+       int rc;
+
+       shift = (3 ^ (address & 3)) << 3;
+       address ^= address & 3;
+       _old = (unsigned int)old << shift;
+       _new = (unsigned int)new << shift;
+       mask = ~(0xff << shift);
+       rc = __cmpxchg_user_key_small(address, &prev, _old, _new, mask, key);
+       *uval = prev >> shift;
+       return rc;
+}
 EXPORT_SYMBOL(__cmpxchg_user_key1);
 
 int __kprobes __cmpxchg_user_key2(unsigned long address, unsigned short *uval,
                                  unsigned short old, unsigned short new, unsigned long key)
 {
        unsigned int prev, shift, mask, _old, _new;
-       unsigned long count;
-       bool sacf_flag;
-       int rc = 0;
+       int rc;
 
-       skey_regions_initialize();
        shift = (2 ^ (address & 2)) << 3;
        address ^= address & 2;
        _old = (unsigned int)old << shift;
        _new = (unsigned int)new << shift;
        mask = ~(0xffff << shift);
-       sacf_flag = enable_sacf_uaccess();
-       asm_inline volatile(
-               "20:    spka    0(%[key])\n"
-               "       sacf    256\n"
-               "       llill   %[count],%[max_loops]\n"
-               "0:     l       %[prev],%[address]\n"
-               "1:     nr      %[prev],%[mask]\n"
-               "       xilf    %[mask],0xffffffff\n"
-               "       or      %[new],%[prev]\n"
-               "       or      %[prev],%[tmp]\n"
-               "2:     lr      %[tmp],%[prev]\n"
-               "3:     cs      %[prev],%[new],%[address]\n"
-               "4:     jnl     5f\n"
-               "       xr      %[tmp],%[prev]\n"
-               "       xr      %[new],%[tmp]\n"
-               "       nr      %[tmp],%[mask]\n"
-               "       jnz     5f\n"
-               "       brct    %[count],2b\n"
-               "5:     sacf    768\n"
-               "       spka    %[default_key]\n"
-               "21:\n"
-               EX_TABLE_UA_LOAD_REG(0b, 5b, %[rc], %[prev])
-               EX_TABLE_UA_LOAD_REG(1b, 5b, %[rc], %[prev])
-               EX_TABLE_UA_LOAD_REG(3b, 5b, %[rc], %[prev])
-               EX_TABLE_UA_LOAD_REG(4b, 5b, %[rc], %[prev])
-               SKEY_REGION(20b, 21b)
-               : [rc] "+&d" (rc),
-               [prev] "=&d" (prev),
-               [address] "+Q" (*(int *)address),
-               [tmp] "+&d" (_old),
-               [new] "+&d" (_new),
-               [mask] "+&d" (mask),
-               [count] "=a" (count)
-               : [key] "%[count]" (key << 4),
-               [default_key] "J" (PAGE_DEFAULT_KEY),
-               [max_loops] "J" (CMPXCHG_USER_KEY_MAX_LOOPS)
-               : "memory", "cc");
-       disable_sacf_uaccess(sacf_flag);
+       rc = __cmpxchg_user_key_small(address, &prev, _old, _new, mask, key);
        *uval = prev >> shift;
-       if (!count)
-               rc = -EAGAIN;
        return rc;
 }
 EXPORT_SYMBOL(__cmpxchg_user_key2);