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
 999001:		mov	r0, #0
100		load_regs
101		.popsection