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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/uaccess.h>
#include <linux/export.h>
#include <linux/mm.h>
#include <asm/asm-extable.h>
#include <asm/ctlreg.h>
#ifdef CONFIG_DEBUG_ENTRY
void debug_user_asce(int exit)
{
struct ctlreg cr1, cr7;
local_ctl_store(1, &cr1);
local_ctl_store(7, &cr7);
if (cr1.val == S390_lowcore.kernel_asce.val && cr7.val == S390_lowcore.user_asce.val)
return;
panic("incorrect ASCE on kernel %s\n"
"cr1: %016lx cr7: %016lx\n"
"kernel: %016lx user: %016lx\n",
exit ? "exit" : "entry", cr1.val, cr7.val,
S390_lowcore.kernel_asce.val, S390_lowcore.user_asce.val);
}
#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 rem;
union oac spec = {
.oac2.key = key,
.oac2.as = PSW_BITS_AS_SECONDARY,
.oac2.k = 1,
.oac2.a = 1,
};
asm volatile(
" lr 0,%[spec]\n"
"0: mvcos 0(%[to]),0(%[from]),%[size]\n"
"1: jz 5f\n"
" algr %[size],%[val]\n"
" slgr %[from],%[val]\n"
" slgr %[to],%[val]\n"
" j 0b\n"
"2: la %[rem],4095(%[from])\n" /* rem = from + 4095 */
" nr %[rem],%[val]\n" /* rem = (from + 4095) & -4096 */
" slgr %[rem],%[from]\n"
" clgr %[size],%[rem]\n" /* copy crosses next page boundary? */
" jnh 6f\n"
"3: mvcos 0(%[to]),0(%[from]),%[rem]\n"
"4: slgr %[size],%[rem]\n"
" j 6f\n"
"5: slgr %[size],%[size]\n"
"6:\n"
EX_TABLE(0b, 2b)
EX_TABLE(1b, 2b)
EX_TABLE(3b, 6b)
EX_TABLE(4b, 6b)
: [size] "+&a" (size), [from] "+&a" (from), [to] "+&a" (to), [rem] "=&a" (rem)
: [val] "a" (-4096UL), [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 rem;
union oac spec = {
.oac1.key = key,
.oac1.as = PSW_BITS_AS_SECONDARY,
.oac1.k = 1,
.oac1.a = 1,
};
asm volatile(
" lr 0,%[spec]\n"
"0: mvcos 0(%[to]),0(%[from]),%[size]\n"
"1: jz 5f\n"
" algr %[size],%[val]\n"
" slgr %[to],%[val]\n"
" slgr %[from],%[val]\n"
" j 0b\n"
"2: la %[rem],4095(%[to])\n" /* rem = to + 4095 */
" nr %[rem],%[val]\n" /* rem = (to + 4095) & -4096 */
" slgr %[rem],%[to]\n"
" clgr %[size],%[rem]\n" /* copy crosses next page boundary? */
" jnh 6f\n"
"3: mvcos 0(%[to]),0(%[from]),%[rem]\n"
"4: slgr %[size],%[rem]\n"
" j 6f\n"
"5: slgr %[size],%[size]\n"
"6:\n"
EX_TABLE(0b, 2b)
EX_TABLE(1b, 2b)
EX_TABLE(3b, 6b)
EX_TABLE(4b, 6b)
: [size] "+&a" (size), [to] "+&a" (to), [from] "+&a" (from), [rem] "=&a" (rem)
: [val] "a" (-4096UL), [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 rem;
union oac spec = {
.oac1.as = PSW_BITS_AS_SECONDARY,
.oac1.a = 1,
};
asm volatile(
" lr 0,%[spec]\n"
"0: mvcos 0(%[to]),0(%[zeropg]),%[size]\n"
"1: jz 5f\n"
" algr %[size],%[val]\n"
" slgr %[to],%[val]\n"
" j 0b\n"
"2: la %[rem],4095(%[to])\n" /* rem = to + 4095 */
" nr %[rem],%[val]\n" /* rem = (to + 4095) & -4096 */
" slgr %[rem],%[to]\n"
" clgr %[size],%[rem]\n" /* copy crosses next page boundary? */
" jnh 6f\n"
"3: mvcos 0(%[to]),0(%[zeropg]),%[rem]\n"
"4: slgr %[size],%[rem]\n"
" j 6f\n"
"5: slgr %[size],%[size]\n"
"6:\n"
EX_TABLE(0b, 2b)
EX_TABLE(1b, 2b)
EX_TABLE(3b, 6b)
EX_TABLE(4b, 6b)
: [size] "+&a" (size), [to] "+&a" (to), [rem] "=&a" (rem)
: [val] "a" (-4096UL), [zeropg] "a" (empty_zero_page), [spec] "d" (spec.val)
: "cc", "memory", "0");
return size;
}
EXPORT_SYMBOL(__clear_user);
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