+++ /dev/null
-/*
- * Optimized user space space access functions based on mvcos.
- *
- * Copyright IBM Corp. 2006
- * Author(s): Martin Schwidefsky (schwidefsky@de.ibm.com),
- * Gerald Schaefer (gerald.schaefer@de.ibm.com)
- */
-
-#include <linux/jump_label.h>
-#include <linux/errno.h>
-#include <linux/init.h>
-#include <linux/mm.h>
-#include <asm/facility.h>
-#include <asm/uaccess.h>
-#include <asm/futex.h>
-#include "uaccess.h"
-
-#ifndef CONFIG_64BIT
-#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
-
-static struct static_key have_mvcos = STATIC_KEY_INIT_TRUE;
-
-static inline unsigned long copy_from_user_mvcos(void *x, const void __user *ptr,
- unsigned long size)
-{
- 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"
- "9: jz 7f\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 4f\n"
- "3: .insn ss,0xc80000000000,0(%4,%2),0(%1),0\n"
- "10:"SLR" %0,%4\n"
- " "ALR" %2,%4\n"
- "4:"LHI" %4,-1\n"
- " "ALR" %4,%0\n" /* copy remaining size, subtract 1 */
- " bras %3,6f\n" /* memset loop */
- " xc 0(1,%2),0(%2)\n"
- "5: xc 0(256,%2),0(%2)\n"
- " la %2,256(%2)\n"
- "6:"AHI" %4,-256\n"
- " jnm 5b\n"
- " ex %4,0(%3)\n"
- " j 8f\n"
- "7:"SLR" %0,%0\n"
- "8: \n"
- EX_TABLE(0b,2b) EX_TABLE(3b,4b) EX_TABLE(9b,2b) EX_TABLE(10b,4b)
- : "+a" (size), "+a" (ptr), "+a" (x), "+a" (tmp1), "=a" (tmp2)
- : "d" (reg0) : "cc", "memory");
- return size;
-}
-
-unsigned long __copy_from_user(void *to, const void __user *from, unsigned long n)
-{
- if (static_key_true(&have_mvcos))
- return copy_from_user_mvcos(to, from, n);
- return copy_from_user_pt(to, from, n);
-}
-EXPORT_SYMBOL(__copy_from_user);
-
-static inline unsigned long copy_to_user_mvcos(void __user *ptr, const void *x,
- unsigned long size)
-{
- 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"
- "6: 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"
- "7:"SLR" %0,%4\n"
- " j 5f\n"
- "4:"SLR" %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)
- : "d" (reg0) : "cc", "memory");
- return size;
-}
-
-unsigned long __copy_to_user(void __user *to, const void *from, unsigned long n)
-{
- if (static_key_true(&have_mvcos))
- return copy_to_user_mvcos(to, from, n);
- return copy_to_user_pt(to, from, n);
-}
-EXPORT_SYMBOL(__copy_to_user);
-
-static inline unsigned long copy_in_user_mvcos(void __user *to, const void __user *from,
- unsigned long size)
-{
- 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;
-}
-
-unsigned long __copy_in_user(void __user *to, const void __user *from, unsigned long n)
-{
- if (static_key_true(&have_mvcos))
- return copy_in_user_mvcos(to, from, n);
- return copy_in_user_pt(to, from, n);
-}
-EXPORT_SYMBOL(__copy_in_user);
-
-static inline unsigned long clear_user_mvcos(void __user *to, unsigned long size)
-{
- 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;
-}
-
-unsigned long __clear_user(void __user *to, unsigned long size)
-{
- if (static_key_true(&have_mvcos))
- return clear_user_mvcos(to, size);
- return clear_user_pt(to, size);
-}
-EXPORT_SYMBOL(__clear_user);
-
-static inline unsigned long strnlen_user_mvcos(const char __user *src,
- unsigned long count)
-{
- unsigned long done, len, offset, len_str;
- char buf[256];
-
- done = 0;
- do {
- offset = (unsigned long)src & ~PAGE_MASK;
- len = min(256UL, PAGE_SIZE - offset);
- len = min(count - done, len);
- if (copy_from_user_mvcos(buf, src, len))
- return 0;
- len_str = strnlen(buf, len);
- done += len_str;
- src += len_str;
- } while ((len_str == len) && (done < count));
- return done + 1;
-}
-
-unsigned long __strnlen_user(const char __user *src, unsigned long count)
-{
- if (static_key_true(&have_mvcos))
- return strnlen_user_mvcos(src, count);
- return strnlen_user_pt(src, count);
-}
-EXPORT_SYMBOL(__strnlen_user);
-
-static inline long strncpy_from_user_mvcos(char *dst, const char __user *src,
- long count)
-{
- unsigned long done, len, offset, len_str;
-
- if (unlikely(count <= 0))
- return 0;
- done = 0;
- do {
- offset = (unsigned long)src & ~PAGE_MASK;
- len = min(count - done, PAGE_SIZE - offset);
- if (copy_from_user_mvcos(dst, src, len))
- return -EFAULT;
- len_str = strnlen(dst, len);
- done += len_str;
- src += len_str;
- dst += len_str;
- } while ((len_str == len) && (done < count));
- return done;
-}
-
-long __strncpy_from_user(char *dst, const char __user *src, long count)
-{
- if (static_key_true(&have_mvcos))
- return strncpy_from_user_mvcos(dst, src, count);
- return strncpy_from_user_pt(dst, src, count);
-}
-EXPORT_SYMBOL(__strncpy_from_user);
-
-/*
- * The uaccess page tabe walk variant can be enforced with the "uaccesspt"
- * kernel parameter. This is mainly for debugging purposes.
- */
-static int force_uaccess_pt __initdata;
-
-static int __init parse_uaccess_pt(char *__unused)
-{
- force_uaccess_pt = 1;
- return 0;
-}
-early_param("uaccesspt", parse_uaccess_pt);
-
-static int __init uaccess_init(void)
-{
- if (IS_ENABLED(CONFIG_32BIT) || force_uaccess_pt || !test_facility(27))
- static_key_slow_dec(&have_mvcos);
- return 0;
-}
-early_initcall(uaccess_init);
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