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// 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/jump_label.h>
#include <linux/uaccess.h>
#include <linux/export.h>
#include <linux/errno.h>
#include <linux/mm.h>
#include <asm/mmu_context.h>
#include <asm/facility.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 */
#ifndef CONFIG_HAVE_MARCH_Z10_FEATURES
static DEFINE_STATIC_KEY_FALSE(have_mvcos);
static int __init uaccess_init(void)
{
if (test_facility(27))
static_branch_enable(&have_mvcos);
return 0;
}
early_initcall(uaccess_init);
static inline int copy_with_mvcos(void)
{
if (static_branch_likely(&have_mvcos))
return 1;
return 0;
}
#else
static inline int copy_with_mvcos(void)
{
return 1;
}
#endif
static inline unsigned long copy_from_user_mvcos(void *x, const void __user *ptr,
unsigned long size)
{
unsigned long tmp1, tmp2;
union oac spec = {
.oac2.as = PSW_BITS_AS_SECONDARY,
.oac2.a = 1,
};
tmp1 = -4096UL;
asm volatile(
" lr 0,%[spec]\n"
"0: .insn ss,0xc80000000000,0(%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: .insn ss,0xc80000000000,0(%4,%2),0(%1),0\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" (ptr), "+a" (x), "+a" (tmp1), "=a" (tmp2)
: [spec] "d" (spec.val)
: "cc", "memory", "0");
return size;
}
static inline unsigned long copy_from_user_mvcp(void *x, const void __user *ptr,
unsigned long size)
{
unsigned long tmp1, tmp2;
tmp1 = -256UL;
asm volatile(
" sacf 0\n"
"0: mvcp 0(%0,%2),0(%1),%3\n"
"7: jz 5f\n"
"1: algr %0,%3\n"
" la %1,256(%1)\n"
" la %2,256(%2)\n"
"2: mvcp 0(%0,%2),0(%1),%3\n"
"8: jnz 1b\n"
" j 5f\n"
"3: la %4,255(%1)\n" /* %4 = ptr + 255 */
" lghi %3,-4096\n"
" nr %4,%3\n" /* %4 = (ptr + 255) & -4096 */
" slgr %4,%1\n"
" clgr %0,%4\n" /* copy crosses next page boundary? */
" jnh 6f\n"
"4: mvcp 0(%4,%2),0(%1),%3\n"
"9: slgr %0,%4\n"
" j 6f\n"
"5: slgr %0,%0\n"
"6: sacf 768\n"
EX_TABLE(0b,3b) EX_TABLE(2b,3b) EX_TABLE(4b,6b)
EX_TABLE(7b,3b) EX_TABLE(8b,3b) EX_TABLE(9b,6b)
: "+a" (size), "+a" (ptr), "+a" (x), "+a" (tmp1), "=a" (tmp2)
: : "cc", "memory");
return size;
}
unsigned long raw_copy_from_user(void *to, const void __user *from, unsigned long n)
{
if (copy_with_mvcos())
return copy_from_user_mvcos(to, from, n);
return copy_from_user_mvcp(to, from, n);
}
EXPORT_SYMBOL(raw_copy_from_user);
static inline unsigned long copy_to_user_mvcos(void __user *ptr, const void *x,
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: .insn ss,0xc80000000000,0(%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: .insn ss,0xc80000000000,0(%4,%1),0(%2),0\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" (ptr), "+a" (x), "+a" (tmp1), "=a" (tmp2)
: [spec] "d" (spec.val)
: "cc", "memory", "0");
return size;
}
static inline unsigned long copy_to_user_mvcs(void __user *ptr, const void *x,
unsigned long size)
{
unsigned long tmp1, tmp2;
tmp1 = -256UL;
asm volatile(
" sacf 0\n"
"0: mvcs 0(%0,%1),0(%2),%3\n"
"7: jz 5f\n"
"1: algr %0,%3\n"
" la %1,256(%1)\n"
" la %2,256(%2)\n"
"2: mvcs 0(%0,%1),0(%2),%3\n"
"8: jnz 1b\n"
" j 5f\n"
"3: la %4,255(%1)\n" /* %4 = ptr + 255 */
" lghi %3,-4096\n"
" nr %4,%3\n" /* %4 = (ptr + 255) & -4096 */
" slgr %4,%1\n"
" clgr %0,%4\n" /* copy crosses next page boundary? */
" jnh 6f\n"
"4: mvcs 0(%4,%1),0(%2),%3\n"
"9: slgr %0,%4\n"
" j 6f\n"
"5: slgr %0,%0\n"
"6: sacf 768\n"
EX_TABLE(0b,3b) EX_TABLE(2b,3b) EX_TABLE(4b,6b)
EX_TABLE(7b,3b) EX_TABLE(8b,3b) EX_TABLE(9b,6b)
: "+a" (size), "+a" (ptr), "+a" (x), "+a" (tmp1), "=a" (tmp2)
: : "cc", "memory");
return size;
}
unsigned long raw_copy_to_user(void __user *to, const void *from, unsigned long n)
{
if (copy_with_mvcos())
return copy_to_user_mvcos(to, from, n);
return copy_to_user_mvcs(to, from, n);
}
EXPORT_SYMBOL(raw_copy_to_user);
static inline unsigned long clear_user_mvcos(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: .insn ss,0xc80000000000,0(%0,%1),0(%4),0\n"
" 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: .insn ss,0xc80000000000,0(%3,%1),0(%4),0\n"
" slgr %0,%3\n"
" j 5f\n"
"4: slgr %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), [spec] "d" (spec.val)
: "cc", "memory", "0");
return size;
}
static inline unsigned long clear_user_xc(void __user *to, unsigned long size)
{
unsigned long tmp1, tmp2;
asm volatile(
" sacf 256\n"
" aghi %0,-1\n"
" jo 5f\n"
" bras %3,3f\n"
" xc 0(1,%1),0(%1)\n"
"0: aghi %0,257\n"
" la %2,255(%1)\n" /* %2 = ptr + 255 */
" srl %2,12\n"
" sll %2,12\n" /* %2 = (ptr + 255) & -4096 */
" slgr %2,%1\n"
" clgr %0,%2\n" /* clear crosses next page boundary? */
" jnh 5f\n"
" aghi %2,-1\n"
"1: ex %2,0(%3)\n"
" aghi %2,1\n"
" slgr %0,%2\n"
" j 5f\n"
"2: xc 0(256,%1),0(%1)\n"
" la %1,256(%1)\n"
"3: aghi %0,-256\n"
" jnm 2b\n"
"4: ex %0,0(%3)\n"
"5: slgr %0,%0\n"
"6: sacf 768\n"
EX_TABLE(1b,6b) EX_TABLE(2b,0b) EX_TABLE(4b,0b)
: "+a" (size), "+a" (to), "=a" (tmp1), "=a" (tmp2)
: : "cc", "memory");
return size;
}
unsigned long __clear_user(void __user *to, unsigned long size)
{
if (copy_with_mvcos())
return clear_user_mvcos(to, size);
return clear_user_xc(to, size);
}
EXPORT_SYMBOL(__clear_user);
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