| // 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; |
| |
| tmp1 = -4096UL; |
| asm volatile( |
| " lghi 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] "K" (0x81UL) |
| : "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; |
| |
| tmp1 = -4096UL; |
| asm volatile( |
| " llilh 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] "K" (0x81UL) |
| : "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; |
| |
| tmp1 = -4096UL; |
| asm volatile( |
| " llilh 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] "K" (0x81UL) |
| : "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); |
