278 lines
7.1 KiB
C
278 lines
7.1 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/*
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* Standard user space access functions based on mvcp/mvcs and doing
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* interesting things in the secondary space mode.
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*
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* Copyright IBM Corp. 2006,2014
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* Author(s): Martin Schwidefsky (schwidefsky@de.ibm.com),
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* Gerald Schaefer (gerald.schaefer@de.ibm.com)
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*/
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#include <linux/jump_label.h>
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#include <linux/uaccess.h>
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#include <linux/export.h>
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#include <linux/errno.h>
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#include <linux/mm.h>
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#include <asm/mmu_context.h>
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#include <asm/facility.h>
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#ifdef CONFIG_DEBUG_ENTRY
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void debug_user_asce(int exit)
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{
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unsigned long cr1, cr7;
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__ctl_store(cr1, 1, 1);
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__ctl_store(cr7, 7, 7);
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if (cr1 == S390_lowcore.kernel_asce && cr7 == S390_lowcore.user_asce)
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return;
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panic("incorrect ASCE on kernel %s\n"
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"cr1: %016lx cr7: %016lx\n"
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"kernel: %016llx user: %016llx\n",
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exit ? "exit" : "entry", cr1, cr7,
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S390_lowcore.kernel_asce, S390_lowcore.user_asce);
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}
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#endif /*CONFIG_DEBUG_ENTRY */
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#ifndef CONFIG_HAVE_MARCH_Z10_FEATURES
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static DEFINE_STATIC_KEY_FALSE(have_mvcos);
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static int __init uaccess_init(void)
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{
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if (test_facility(27))
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static_branch_enable(&have_mvcos);
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return 0;
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}
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early_initcall(uaccess_init);
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static inline int copy_with_mvcos(void)
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{
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if (static_branch_likely(&have_mvcos))
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return 1;
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return 0;
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}
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#else
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static inline int copy_with_mvcos(void)
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{
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return 1;
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}
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#endif
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static inline unsigned long copy_from_user_mvcos(void *x, const void __user *ptr,
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unsigned long size)
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{
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unsigned long tmp1, tmp2;
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tmp1 = -4096UL;
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asm volatile(
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" lghi 0,%[spec]\n"
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"0: .insn ss,0xc80000000000,0(%0,%2),0(%1),0\n"
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"6: jz 4f\n"
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"1: algr %0,%3\n"
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" slgr %1,%3\n"
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" slgr %2,%3\n"
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" j 0b\n"
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"2: la %4,4095(%1)\n"/* %4 = ptr + 4095 */
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" nr %4,%3\n" /* %4 = (ptr + 4095) & -4096 */
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" slgr %4,%1\n"
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" clgr %0,%4\n" /* copy crosses next page boundary? */
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" jnh 5f\n"
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"3: .insn ss,0xc80000000000,0(%4,%2),0(%1),0\n"
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"7: slgr %0,%4\n"
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" j 5f\n"
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"4: slgr %0,%0\n"
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"5:\n"
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EX_TABLE(0b,2b) EX_TABLE(3b,5b) EX_TABLE(6b,2b) EX_TABLE(7b,5b)
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: "+a" (size), "+a" (ptr), "+a" (x), "+a" (tmp1), "=a" (tmp2)
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: [spec] "K" (0x81UL)
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: "cc", "memory", "0");
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return size;
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}
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static inline unsigned long copy_from_user_mvcp(void *x, const void __user *ptr,
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unsigned long size)
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{
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unsigned long tmp1, tmp2;
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tmp1 = -256UL;
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asm volatile(
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" sacf 0\n"
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"0: mvcp 0(%0,%2),0(%1),%3\n"
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"7: jz 5f\n"
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"1: algr %0,%3\n"
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" la %1,256(%1)\n"
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" la %2,256(%2)\n"
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"2: mvcp 0(%0,%2),0(%1),%3\n"
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"8: jnz 1b\n"
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" j 5f\n"
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"3: la %4,255(%1)\n" /* %4 = ptr + 255 */
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" lghi %3,-4096\n"
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" nr %4,%3\n" /* %4 = (ptr + 255) & -4096 */
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" slgr %4,%1\n"
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" clgr %0,%4\n" /* copy crosses next page boundary? */
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" jnh 6f\n"
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"4: mvcp 0(%4,%2),0(%1),%3\n"
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"9: slgr %0,%4\n"
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" j 6f\n"
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"5: slgr %0,%0\n"
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"6: sacf 768\n"
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EX_TABLE(0b,3b) EX_TABLE(2b,3b) EX_TABLE(4b,6b)
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EX_TABLE(7b,3b) EX_TABLE(8b,3b) EX_TABLE(9b,6b)
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: "+a" (size), "+a" (ptr), "+a" (x), "+a" (tmp1), "=a" (tmp2)
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: : "cc", "memory");
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return size;
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}
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unsigned long raw_copy_from_user(void *to, const void __user *from, unsigned long n)
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{
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if (copy_with_mvcos())
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return copy_from_user_mvcos(to, from, n);
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return copy_from_user_mvcp(to, from, n);
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}
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EXPORT_SYMBOL(raw_copy_from_user);
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static inline unsigned long copy_to_user_mvcos(void __user *ptr, const void *x,
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unsigned long size)
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{
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unsigned long tmp1, tmp2;
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tmp1 = -4096UL;
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asm volatile(
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" llilh 0,%[spec]\n"
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"0: .insn ss,0xc80000000000,0(%0,%1),0(%2),0\n"
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"6: jz 4f\n"
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"1: algr %0,%3\n"
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" slgr %1,%3\n"
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" slgr %2,%3\n"
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" j 0b\n"
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"2: la %4,4095(%1)\n"/* %4 = ptr + 4095 */
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" nr %4,%3\n" /* %4 = (ptr + 4095) & -4096 */
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" slgr %4,%1\n"
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" clgr %0,%4\n" /* copy crosses next page boundary? */
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" jnh 5f\n"
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"3: .insn ss,0xc80000000000,0(%4,%1),0(%2),0\n"
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"7: slgr %0,%4\n"
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" j 5f\n"
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"4: slgr %0,%0\n"
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"5:\n"
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EX_TABLE(0b,2b) EX_TABLE(3b,5b) EX_TABLE(6b,2b) EX_TABLE(7b,5b)
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: "+a" (size), "+a" (ptr), "+a" (x), "+a" (tmp1), "=a" (tmp2)
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: [spec] "K" (0x81UL)
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: "cc", "memory", "0");
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return size;
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}
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static inline unsigned long copy_to_user_mvcs(void __user *ptr, const void *x,
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unsigned long size)
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{
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unsigned long tmp1, tmp2;
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tmp1 = -256UL;
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asm volatile(
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" sacf 0\n"
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"0: mvcs 0(%0,%1),0(%2),%3\n"
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"7: jz 5f\n"
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"1: algr %0,%3\n"
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" la %1,256(%1)\n"
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" la %2,256(%2)\n"
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"2: mvcs 0(%0,%1),0(%2),%3\n"
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"8: jnz 1b\n"
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" j 5f\n"
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"3: la %4,255(%1)\n" /* %4 = ptr + 255 */
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" lghi %3,-4096\n"
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" nr %4,%3\n" /* %4 = (ptr + 255) & -4096 */
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" slgr %4,%1\n"
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" clgr %0,%4\n" /* copy crosses next page boundary? */
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" jnh 6f\n"
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"4: mvcs 0(%4,%1),0(%2),%3\n"
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"9: slgr %0,%4\n"
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" j 6f\n"
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"5: slgr %0,%0\n"
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"6: sacf 768\n"
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EX_TABLE(0b,3b) EX_TABLE(2b,3b) EX_TABLE(4b,6b)
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EX_TABLE(7b,3b) EX_TABLE(8b,3b) EX_TABLE(9b,6b)
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: "+a" (size), "+a" (ptr), "+a" (x), "+a" (tmp1), "=a" (tmp2)
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: : "cc", "memory");
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return size;
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}
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unsigned long raw_copy_to_user(void __user *to, const void *from, unsigned long n)
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{
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if (copy_with_mvcos())
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return copy_to_user_mvcos(to, from, n);
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return copy_to_user_mvcs(to, from, n);
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}
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EXPORT_SYMBOL(raw_copy_to_user);
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static inline unsigned long clear_user_mvcos(void __user *to, unsigned long size)
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{
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unsigned long tmp1, tmp2;
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tmp1 = -4096UL;
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asm volatile(
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" llilh 0,%[spec]\n"
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"0: .insn ss,0xc80000000000,0(%0,%1),0(%4),0\n"
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"6: jz 4f\n"
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"1: algr %0,%2\n"
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" slgr %1,%2\n"
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" j 0b\n"
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"2: la %3,4095(%1)\n"/* %4 = to + 4095 */
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" nr %3,%2\n" /* %4 = (to + 4095) & -4096 */
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" slgr %3,%1\n"
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" clgr %0,%3\n" /* copy crosses next page boundary? */
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" jnh 5f\n"
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"3: .insn ss,0xc80000000000,0(%3,%1),0(%4),0\n"
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"7: slgr %0,%3\n"
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" j 5f\n"
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"4: slgr %0,%0\n"
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"5:\n"
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EX_TABLE(0b,2b) EX_TABLE(6b,2b) EX_TABLE(3b,5b) EX_TABLE(7b,5b)
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: "+&a" (size), "+&a" (to), "+a" (tmp1), "=&a" (tmp2)
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: "a" (empty_zero_page), [spec] "K" (0x81UL)
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: "cc", "memory", "0");
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return size;
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}
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static inline unsigned long clear_user_xc(void __user *to, unsigned long size)
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{
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unsigned long tmp1, tmp2;
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asm volatile(
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" sacf 256\n"
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" aghi %0,-1\n"
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" jo 5f\n"
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" bras %3,3f\n"
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" xc 0(1,%1),0(%1)\n"
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"0: aghi %0,257\n"
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" la %2,255(%1)\n" /* %2 = ptr + 255 */
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" srl %2,12\n"
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" sll %2,12\n" /* %2 = (ptr + 255) & -4096 */
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" slgr %2,%1\n"
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" clgr %0,%2\n" /* clear crosses next page boundary? */
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" jnh 5f\n"
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" aghi %2,-1\n"
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"1: ex %2,0(%3)\n"
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" aghi %2,1\n"
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" slgr %0,%2\n"
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" j 5f\n"
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"2: xc 0(256,%1),0(%1)\n"
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" la %1,256(%1)\n"
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"3: aghi %0,-256\n"
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" jnm 2b\n"
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"4: ex %0,0(%3)\n"
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"5: slgr %0,%0\n"
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"6: sacf 768\n"
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EX_TABLE(1b,6b) EX_TABLE(2b,0b) EX_TABLE(4b,0b)
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: "+a" (size), "+a" (to), "=a" (tmp1), "=a" (tmp2)
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: : "cc", "memory");
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return size;
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}
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unsigned long __clear_user(void __user *to, unsigned long size)
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{
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if (copy_with_mvcos())
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return clear_user_mvcos(to, size);
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return clear_user_xc(to, size);
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}
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EXPORT_SYMBOL(__clear_user);
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