arch/arm/lib/csumpartialcopyuser.S

   1 /* SPDX-License-Identifier: GPL-2.0-only */
   2 /*
   3  *  linux/arch/arm/lib/csumpartialcopyuser.S
   4  *
   5  *  Copyright (C) 1995-1998 Russell King
   6  *
   7  * 27/03/03 Ian Molton Clean up CONFIG_CPU
   8  */
   9 #include <linux/linkage.h>
  10 #include <asm/assembler.h>
  11 #include <asm/errno.h>
  12 #include <asm/asm-offsets.h>
  13
  14                 .text
  15
  16 #if defined(CONFIG_CPU_SW_DOMAIN_PAN)
  17
  18                 .macro  save_regs
  19                 mrc     p15, 0, ip, c3, c0, 0
  20                 stmfd   sp!, {r1, r2, r4 - r8, ip, lr}
  21                 uaccess_enable ip
  22                 .endm
  23
  24                 .macro  load_regs
  25                 ldmfd   sp!, {r1, r2, r4 - r8, ip, lr}
  26                 mcr     p15, 0, ip, c3, c0, 0
  27                 ret     lr
  28                 .endm
  29
  30 #elif defined(CONFIG_CPU_TTBR0_PAN)
  31
  32                 .macro  save_regs
  33                 mrc     p15, 0, ip, c2, c0, 2           @ read TTBCR
  34                 stmfd   sp!, {r1, r2, r4 - r8, ip, lr}
  35                 uaccess_enable ip
  36                 .endm
  37
  38                 .macro  load_regs
  39                 ldmfd   sp!, {r1, r2, r4 - r8, ip, lr}
  40                 mcr     p15, 0, ip, c2, c0, 2           @ restore TTBCR
  41                 ret     lr
  42                 .endm
  43
  44 #else
  45
  46                 .macro  save_regs
  47                 stmfd   sp!, {r1, r2, r4 - r8, lr}
  48                 .endm
  49
  50                 .macro  load_regs
  51                 ldmfd   sp!, {r1, r2, r4 - r8, pc}
  52                 .endm
  53
  54 #endif
  55
  56                 .macro  load1b, reg1
  57                 ldrusr  \reg1, r0, 1
  58                 .endm
  59
  60                 .macro  load2b, reg1, reg2
  61                 ldrusr  \reg1, r0, 1
  62                 ldrusr  \reg2, r0, 1
  63                 .endm
  64
  65                 .macro  load1l, reg1
  66                 ldrusr  \reg1, r0, 4
  67                 .endm
  68
  69                 .macro  load2l, reg1, reg2
  70                 ldrusr  \reg1, r0, 4
  71                 ldrusr  \reg2, r0, 4
  72                 .endm
  73
  74                 .macro  load4l, reg1, reg2, reg3, reg4
  75                 ldrusr  \reg1, r0, 4
  76                 ldrusr  \reg2, r0, 4
  77                 ldrusr  \reg3, r0, 4
  78                 ldrusr  \reg4, r0, 4
  79                 .endm
  80
  81 /*
  82  * unsigned int
  83  * csum_partial_copy_from_user(const char *src, char *dst, int len)
  84  *  r0 = src, r1 = dst, r2 = len
  85  *  Returns : r0 = checksum or 0
  86  */
  87
  88 #define FN_ENTRY        ENTRY(csum_partial_copy_from_user)
  89 #define FN_EXIT         ENDPROC(csum_partial_copy_from_user)
  90
  91 #include "csumpartialcopygeneric.S"
  92
  93 /*
  94  * We report fault by returning 0 csum - impossible in normal case, since
  95  * we start with 0xffffffff for initial sum.
  96  */
  97                 .pushsection .text.fixup,"ax"
  98                 .align  4
  99 9001:           mov     r0, #0
 100                 load_regs
 101                 .popsection