arch/arm64/include/asm/assembler.h

/*
 * Based on arch/arm/include/asm/assembler.h
 *
 * Copyright (C) 1996-2000 Russell King
 * Copyright (C) 2012 ARM Ltd.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
#ifndef __ASSEMBLY__
#error "Only include this from assembly code"
#endif

#ifndef __ASM_ASSEMBLER_H
#define __ASM_ASSEMBLER_H

#include <asm/cputype.h>
#include <asm/ptrace.h>
#include <asm/thread_info.h>

/*
 * Stack pushing/popping (register pairs only). Equivalent to store decrement
 * before, load increment after.
 */
	.macro	push, xreg1, xreg2
	stp	\xreg1, \xreg2, [sp, #-16]!
	.endm

	.macro	pop, xreg1, xreg2
	ldp	\xreg1, \xreg2, [sp], #16
	.endm

/*
 * Enable and disable interrupts.
 */
	.macro	disable_irq
	msr	daifset, #2
	.endm

	.macro	enable_irq
	msr	daifclr, #2
	.endm

/*
 * Enable and disable debug exceptions.
 */
	.macro	disable_dbg
	msr	daifset, #8
	.endm

	.macro	enable_dbg
	msr	daifclr, #8
	.endm

	.macro	disable_step_tsk, flgs, tmp
	tbz	\flgs, #TIF_SINGLESTEP, 9990f
	mrs	\tmp, mdscr_el1
	bic	\tmp, \tmp, #1
	msr	mdscr_el1, \tmp
	isb	// Synchronise with enable_dbg
9990:
	.endm

	.macro	enable_step_tsk, flgs, tmp
	tbz	\flgs, #TIF_SINGLESTEP, 9990f
	disable_dbg
	mrs	\tmp, mdscr_el1
	orr	\tmp, \tmp, #1
	msr	mdscr_el1, \tmp
9990:
	.endm

/*
 * Enable both debug exceptions and interrupts. This is likely to be
 * faster than two daifclr operations, since writes to this register
 * are self-synchronising.
 */
	.macro	enable_dbg_and_irq
	msr	daifclr, #(8 | 2)
	.endm

/*
 * SMP data memory barrier
 */
	.macro	smp_dmb, opt
	dmb	\opt
	.endm

#define USER(l, x...)				\
9999:	x;					\
	.section __ex_table,"a";		\
	.align	3;				\
	.quad	9999b,l;			\
	.previous

/*
 * Register aliases.
 */
lr	.req	x30		// link register

/*
 * Vector entry
 */
	 .macro	ventry	label
	.align	7
	b	\label
	.endm

/*
 * Select code when configured for BE.
 */
#ifdef CONFIG_CPU_BIG_ENDIAN
#define CPU_BE(code...) code
#else
#define CPU_BE(code...)
#endif

/*
 * Select code when configured for LE.
 */
#ifdef CONFIG_CPU_BIG_ENDIAN
#define CPU_LE(code...)
#else
#define CPU_LE(code...) code
#endif

/*
 * Define a macro that constructs a 64-bit value by concatenating two
 * 32-bit registers. Note that on big endian systems the order of the
 * registers is swapped.
 */
#ifndef CONFIG_CPU_BIG_ENDIAN
	.macro	regs_to_64, rd, lbits, hbits
#else
	.macro	regs_to_64, rd, hbits, lbits
#endif
	orr	\rd, \lbits, \hbits, lsl #32
	.endm

/*
 * Pseudo-ops for PC-relative adr/ldr/str <reg>, <symbol> where
 * <symbol> is within the range +/- 4 GB of the PC.
 */
	/*
	 * @dst: destination register (64 bit wide)
	 * @sym: name of the symbol
	 * @tmp: optional scratch register to be used if <dst> == sp, which
	 *       is not allowed in an adrp instruction
	 */
	.macro	adr_l, dst, sym, tmp=
	.ifb	\tmp
	adrp	\dst, \sym
	add	\dst, \dst, :lo12:\sym
	.else
	adrp	\tmp, \sym
	add	\dst, \tmp, :lo12:\sym
	.endif
	.endm

	/*
	 * @dst: destination register (32 or 64 bit wide)
	 * @sym: name of the symbol
	 * @tmp: optional 64-bit scratch register to be used if <dst> is a
	 *       32-bit wide register, in which case it cannot be used to hold
	 *       the address
	 */
	.macro	ldr_l, dst, sym, tmp=
	.ifb	\tmp
	adrp	\dst, \sym
	ldr	\dst, [\dst, :lo12:\sym]
	.else
	adrp	\tmp, \sym
	ldr	\dst, [\tmp, :lo12:\sym]
	.endif
	.endm

	/*
	 * @src: source register (32 or 64 bit wide)
	 * @sym: name of the symbol
	 * @tmp: mandatory 64-bit scratch register to calculate the address
	 *       while <src> needs to be preserved.
	 */
	.macro	str_l, src, sym, tmp
	adrp	\tmp, \sym
	str	\src, [\tmp, :lo12:\sym]
	.endm

/*
 * Annotate a function as position independent, i.e., safe to be called before
 * the kernel virtual mapping is activated.
 */
#define ENDPIPROC(x)			\
	.globl	__pi_##x;		\
	.type 	__pi_##x, %function;	\
	.set	__pi_##x, x;		\
	.size	__pi_##x, . - x;	\
	ENDPROC(x)

	/*
	 * mov_q - move an immediate constant into a 64-bit register using
	 *         between 2 and 4 movz/movk instructions (depending on the
	 *         magnitude and sign of the operand)
	 */
	.macro	mov_q, reg, val
	.if (((\val) >> 31) == 0 || ((\val) >> 31) == 0x1ffffffff)
	movz	\reg, :abs_g1_s:\val
	.else
	.if (((\val) >> 47) == 0 || ((\val) >> 47) == 0x1ffff)
	movz	\reg, :abs_g2_s:\val
	.else
	movz	\reg, :abs_g3:\val
	movk	\reg, :abs_g2_nc:\val
	.endif
	movk	\reg, :abs_g1_nc:\val
	.endif
	movk	\reg, :abs_g0_nc:\val
	.endm

/*
 * Check the MIDR_EL1 of the current CPU for a given model and a range of
 * variant/revision. See asm/cputype.h for the macros used below.
 *
 *	model:		MIDR_CPU_PART of CPU
 *	rv_min:		Minimum of MIDR_CPU_VAR_REV()
 *	rv_max:		Maximum of MIDR_CPU_VAR_REV()
 *	res:		Result register.
 *	tmp1, tmp2, tmp3: Temporary registers
 *
 * Corrupts: res, tmp1, tmp2, tmp3
 * Returns:  0, if the CPU id doesn't match. Non-zero otherwise
 */
	.macro	cpu_midr_match model, rv_min, rv_max, res, tmp1, tmp2, tmp3
	mrs		\res, midr_el1
	mov_q		\tmp1, (MIDR_REVISION_MASK | MIDR_VARIANT_MASK)
	mov_q		\tmp2, MIDR_CPU_PART_MASK
	and		\tmp3, \res, \tmp2	// Extract model
	and		\tmp1, \res, \tmp1	// rev & variant
	mov_q		\tmp2, \model
	cmp		\tmp3, \tmp2
	cset		\res, eq
	cbz		\res, .Ldone\@		// Model matches ?

	.if (\rv_min != 0)			// Skip min check if rv_min == 0
	mov_q		\tmp3, \rv_min
	cmp		\tmp1, \tmp3
	cset		\res, ge
	.endif					// \rv_min != 0
	/* Skip rv_max check if rv_min == rv_max && rv_min != 0 */
	.if ((\rv_min != \rv_max) || \rv_min == 0)
	mov_q		\tmp2, \rv_max
	cmp		\tmp1, \tmp2
	cset		\tmp2, le
	and		\res, \res, \tmp2
	.endif
.Ldone\@:
	.endm

#endif	/* __ASM_ASSEMBLER_H */