blob: d44214072779e7abbbe0862a3af28b2c01954cbb [file] [log] [blame]
// SPDX-License-Identifier: GPL-2.0
/*
* Standard user space access functions based on mvcp/mvcs and doing
* interesting things in the secondary space mode.
*
* Copyright IBM Corp. 2006,2014
* Author(s): Martin Schwidefsky (schwidefsky@de.ibm.com),
* Gerald Schaefer (gerald.schaefer@de.ibm.com)
*/
#include <linux/uaccess.h>
#include <linux/export.h>
#include <linux/mm.h>
#include <asm/asm-extable.h>
#ifdef CONFIG_DEBUG_ENTRY
void debug_user_asce(int exit)
{
unsigned long cr1, cr7;
__ctl_store(cr1, 1, 1);
__ctl_store(cr7, 7, 7);
if (cr1 == S390_lowcore.kernel_asce && cr7 == S390_lowcore.user_asce)
return;
panic("incorrect ASCE on kernel %s\n"
"cr1: %016lx cr7: %016lx\n"
"kernel: %016llx user: %016llx\n",
exit ? "exit" : "entry", cr1, cr7,
S390_lowcore.kernel_asce, S390_lowcore.user_asce);
}
#endif /*CONFIG_DEBUG_ENTRY */
static unsigned long raw_copy_from_user_key(void *to, const void __user *from,
unsigned long size, unsigned long key)
{
unsigned long tmp1, tmp2;
union oac spec = {
.oac2.key = key,
.oac2.as = PSW_BITS_AS_SECONDARY,
.oac2.k = 1,
.oac2.a = 1,
};
tmp1 = -4096UL;
asm volatile(
" lr 0,%[spec]\n"
"0: mvcos 0(%2),0(%1),%0\n"
"6: jz 4f\n"
"1: algr %0,%3\n"
" slgr %1,%3\n"
" slgr %2,%3\n"
" j 0b\n"
"2: la %4,4095(%1)\n"/* %4 = ptr + 4095 */
" nr %4,%3\n" /* %4 = (ptr + 4095) & -4096 */
" slgr %4,%1\n"
" clgr %0,%4\n" /* copy crosses next page boundary? */
" jnh 5f\n"
"3: mvcos 0(%2),0(%1),%4\n"
"7: slgr %0,%4\n"
" j 5f\n"
"4: slgr %0,%0\n"
"5:\n"
EX_TABLE(0b,2b) EX_TABLE(3b,5b) EX_TABLE(6b,2b) EX_TABLE(7b,5b)
: "+a" (size), "+a" (from), "+a" (to), "+a" (tmp1), "=a" (tmp2)
: [spec] "d" (spec.val)
: "cc", "memory", "0");
return size;
}
unsigned long raw_copy_from_user(void *to, const void __user *from, unsigned long n)
{
return raw_copy_from_user_key(to, from, n, 0);
}
EXPORT_SYMBOL(raw_copy_from_user);
unsigned long _copy_from_user_key(void *to, const void __user *from,
unsigned long n, unsigned long key)
{
unsigned long res = n;
might_fault();
if (!should_fail_usercopy()) {
instrument_copy_from_user_before(to, from, n);
res = raw_copy_from_user_key(to, from, n, key);
instrument_copy_from_user_after(to, from, n, res);
}
if (unlikely(res))
memset(to + (n - res), 0, res);
return res;
}
EXPORT_SYMBOL(_copy_from_user_key);
static unsigned long raw_copy_to_user_key(void __user *to, const void *from,
unsigned long size, unsigned long key)
{
unsigned long tmp1, tmp2;
union oac spec = {
.oac1.key = key,
.oac1.as = PSW_BITS_AS_SECONDARY,
.oac1.k = 1,
.oac1.a = 1,
};
tmp1 = -4096UL;
asm volatile(
" lr 0,%[spec]\n"
"0: mvcos 0(%1),0(%2),%0\n"
"6: jz 4f\n"
"1: algr %0,%3\n"
" slgr %1,%3\n"
" slgr %2,%3\n"
" j 0b\n"
"2: la %4,4095(%1)\n"/* %4 = ptr + 4095 */
" nr %4,%3\n" /* %4 = (ptr + 4095) & -4096 */
" slgr %4,%1\n"
" clgr %0,%4\n" /* copy crosses next page boundary? */
" jnh 5f\n"
"3: mvcos 0(%1),0(%2),%4\n"
"7: slgr %0,%4\n"
" j 5f\n"
"4: slgr %0,%0\n"
"5:\n"
EX_TABLE(0b,2b) EX_TABLE(3b,5b) EX_TABLE(6b,2b) EX_TABLE(7b,5b)
: "+a" (size), "+a" (to), "+a" (from), "+a" (tmp1), "=a" (tmp2)
: [spec] "d" (spec.val)
: "cc", "memory", "0");
return size;
}
unsigned long raw_copy_to_user(void __user *to, const void *from, unsigned long n)
{
return raw_copy_to_user_key(to, from, n, 0);
}
EXPORT_SYMBOL(raw_copy_to_user);
unsigned long _copy_to_user_key(void __user *to, const void *from,
unsigned long n, unsigned long key)
{
might_fault();
if (should_fail_usercopy())
return n;
instrument_copy_to_user(to, from, n);
return raw_copy_to_user_key(to, from, n, key);
}
EXPORT_SYMBOL(_copy_to_user_key);
unsigned long __clear_user(void __user *to, unsigned long size)
{
unsigned long tmp1, tmp2;
union oac spec = {
.oac1.as = PSW_BITS_AS_SECONDARY,
.oac1.a = 1,
};
tmp1 = -4096UL;
asm volatile(
" lr 0,%[spec]\n"
"0: mvcos 0(%1),0(%4),%0\n"
"6: jz 4f\n"
"1: algr %0,%2\n"
" slgr %1,%2\n"
" j 0b\n"
"2: la %3,4095(%1)\n"/* %4 = to + 4095 */
" nr %3,%2\n" /* %4 = (to + 4095) & -4096 */
" slgr %3,%1\n"
" clgr %0,%3\n" /* copy crosses next page boundary? */
" jnh 5f\n"
"3: mvcos 0(%1),0(%4),%3\n"
"7: slgr %0,%3\n"
" j 5f\n"
"4: slgr %0,%0\n"
"5:\n"
EX_TABLE(0b,2b) EX_TABLE(6b,2b) EX_TABLE(3b,5b) EX_TABLE(7b,5b)
: "+&a" (size), "+&a" (to), "+a" (tmp1), "=&a" (tmp2)
: "a" (empty_zero_page), [spec] "d" (spec.val)
: "cc", "memory", "0");
return size;
}
EXPORT_SYMBOL(__clear_user);