arch/arm64/include/asm/sysreg.h

Source file repositories/reference/linux-study-clean/arch/arm64/include/asm/sysreg.h

File Facts

System
Linux kernel
Corpus path
arch/arm64/include/asm/sysreg.h
Extension
.h
Size
49261 bytes
Lines
1272
Domain
Architecture Layer
Bucket
arch/arm64
Inferred role
Architecture Layer: implementation source
Status
source implementation candidate

Why This File Exists

CPU and platform-specific kernel glue: boot entry, traps, syscall entry, interrupts, page tables, context switch, and low-level barriers.

Dependency Surface

Detected Declarations

Annotated Snippet

#ifndef __ASM_SYSREG_H
#define __ASM_SYSREG_H

#include <linux/bits.h>
#include <linux/stringify.h>
#include <linux/kasan-tags.h>
#include <linux/kconfig.h>

#include <asm/gpr-num.h>

/*
 * ARMv8 ARM reserves the following encoding for system registers:
 * (Ref: ARMv8 ARM, Section: "System instruction class encoding overview",
 *  C5.2, version:ARM DDI 0487A.f)
 *	[20-19] : Op0
 *	[18-16] : Op1
 *	[15-12] : CRn
 *	[11-8]  : CRm
 *	[7-5]   : Op2
 */
#define Op0_shift	19
#define Op0_mask	0x3
#define Op1_shift	16
#define Op1_mask	0x7
#define CRn_shift	12
#define CRn_mask	0xf
#define CRm_shift	8
#define CRm_mask	0xf
#define Op2_shift	5
#define Op2_mask	0x7

#define sys_reg(op0, op1, crn, crm, op2) \
	(((op0) << Op0_shift) | ((op1) << Op1_shift) | \
	 ((crn) << CRn_shift) | ((crm) << CRm_shift) | \
	 ((op2) << Op2_shift))

#define sys_insn	sys_reg

#define sys_reg_Op0(id)	(((id) >> Op0_shift) & Op0_mask)
#define sys_reg_Op1(id)	(((id) >> Op1_shift) & Op1_mask)
#define sys_reg_CRn(id)	(((id) >> CRn_shift) & CRn_mask)
#define sys_reg_CRm(id)	(((id) >> CRm_shift) & CRm_mask)
#define sys_reg_Op2(id)	(((id) >> Op2_shift) & Op2_mask)

#ifndef CONFIG_BROKEN_GAS_INST

#ifdef __ASSEMBLER__
// The space separator is omitted so that __emit_inst(x) can be parsed as
// either an assembler directive or an assembler macro argument.
#define __emit_inst(x)			.inst(x)
#else
#define __emit_inst(x)			".inst " __stringify((x)) "\n\t"
#endif

#else  /* CONFIG_BROKEN_GAS_INST */

#ifndef CONFIG_CPU_BIG_ENDIAN
#define __INSTR_BSWAP(x)		(x)
#else  /* CONFIG_CPU_BIG_ENDIAN */
#define __INSTR_BSWAP(x)		((((x) << 24) & 0xff000000)	| \
					 (((x) <<  8) & 0x00ff0000)	| \
					 (((x) >>  8) & 0x0000ff00)	| \
					 (((x) >> 24) & 0x000000ff))
#endif	/* CONFIG_CPU_BIG_ENDIAN */

#ifdef __ASSEMBLER__
#define __emit_inst(x)			.long __INSTR_BSWAP(x)
#else  /* __ASSEMBLER__ */
#define __emit_inst(x)			".long " __stringify(__INSTR_BSWAP(x)) "\n\t"
#endif	/* __ASSEMBLER__ */

#endif	/* CONFIG_BROKEN_GAS_INST */

/*
 * Instructions for modifying PSTATE fields.
 * As per Arm ARM for v8-A, Section "C.5.1.3 op0 == 0b00, architectural hints,
 * barriers and CLREX, and PSTATE access", ARM DDI 0487 C.a, system instructions
 * for accessing PSTATE fields have the following encoding:
 *	Op0 = 0, CRn = 4
 *	Op1, Op2 encodes the PSTATE field modified and defines the constraints.
 *	CRm = Imm4 for the instruction.
 *	Rt = 0x1f
 */
#define pstate_field(op1, op2)		((op1) << Op1_shift | (op2) << Op2_shift)
#define PSTATE_Imm_shift		CRm_shift
#define ENCODE_PSTATE(x, r)		(0xd500401f | PSTATE_ ## r | ((!!x) << PSTATE_Imm_shift))
#define SET_PSTATE(x, r)		__emit_inst(ENCODE_PSTATE(x, r))

#define PSTATE_PAN			pstate_field(0, 4)
#define PSTATE_UAO			pstate_field(0, 3)

Annotation

Implementation Notes