arch/arc/include/asm/entry.h - linux - Git at Google

 /* SPDX-License-Identifier: GPL-2.0-only */
 /*
  * Copyright (C) 2014-15 Synopsys, Inc. (www.synopsys.com)
  * Copyright (C) 2004, 2007-2010, 2011-2012 Synopsys, Inc. (www.synopsys.com)
  */

 #ifndef __ASM_ARC_ENTRY_H
 #define __ASM_ARC_ENTRY_H

 #include <asm/unistd.h>		/* For NR_syscalls defination */
 #include <asm/arcregs.h>
 #include <asm/ptrace.h>
 #include <asm/processor.h>	/* For VMALLOC_START */
 #include <asm/mmu.h>

 #ifdef CONFIG_ISA_ARCOMPACT
 #include <asm/entry-compact.h>	/* ISA specific bits */
 #else
 #include <asm/entry-arcv2.h>
 #endif

 /* Note on the LD/ST addr modes with addr reg wback
  *
  * LD.a same as LD.aw
  *
  * LD.a    reg1, [reg2, x]  => Pre Incr
  *      Eff Addr for load = [reg2 + x]
  *
  * LD.ab   reg1, [reg2, x]  => Post Incr
  *      Eff Addr for load = [reg2]
  */

 .macro PUSH reg
 	st.a	\reg, [sp, -4]
 .endm

 .macro PUSHAX aux
 	lr	r9, [\aux]
 	PUSH	r9
 .endm

 .macro POP reg
 	ld.ab	\reg, [sp, 4]
 .endm

 .macro POPAX aux
 	POP	r9
 	sr	r9, [\aux]
 .endm

 /*--------------------------------------------------------------
  * Helpers to save/restore Scratch Regs:
  * used by Interrupt/Exception Prologue/Epilogue
  *-------------------------------------------------------------*/
 .macro  SAVE_R0_TO_R12
 	PUSH	r0
 	PUSH	r1
 	PUSH	r2
 	PUSH	r3
 	PUSH	r4
 	PUSH	r5
 	PUSH	r6
 	PUSH	r7
 	PUSH	r8
 	PUSH	r9
 	PUSH	r10
 	PUSH	r11
 	PUSH	r12
 .endm

 .macro RESTORE_R12_TO_R0
 	POP	r12
 	POP	r11
 	POP	r10
 	POP	r9
 	POP	r8
 	POP	r7
 	POP	r6
 	POP	r5
 	POP	r4
 	POP	r3
 	POP	r2
 	POP	r1
 	POP	r0

 .endm

 /*--------------------------------------------------------------
  * Helpers to save/restore callee-saved regs:
  * used by several macros below
  *-------------------------------------------------------------*/
 .macro SAVE_R13_TO_R24
 	PUSH	r13
 	PUSH	r14
 	PUSH	r15
 	PUSH	r16
 	PUSH	r17
 	PUSH	r18
 	PUSH	r19
 	PUSH	r20
 	PUSH	r21
 	PUSH	r22
 	PUSH	r23
 	PUSH	r24
 .endm

 .macro RESTORE_R24_TO_R13
 	POP	r24
 	POP	r23
 	POP	r22
 	POP	r21
 	POP	r20
 	POP	r19
 	POP	r18
 	POP	r17
 	POP	r16
 	POP	r15
 	POP	r14
 	POP	r13
 .endm

 /*--------------------------------------------------------------
  * Collect User Mode callee regs as struct callee_regs - needed by
  * fork/do_signal/unaligned-access-emulation.
  * (By default only scratch regs are saved on entry to kernel)
  *
  * Special handling for r25 if used for caching Task Pointer.
  * It would have been saved in task->thread.user_r25 already, but to keep
  * the interface same it is copied into regular r25 placeholder in
  * struct callee_regs.
  *-------------------------------------------------------------*/
 .macro SAVE_CALLEE_SAVED_USER

 	mov	r12, sp		; save SP as ref to pt_regs
 	SAVE_R13_TO_R24

 #ifdef CONFIG_ARC_CURR_IN_REG
 	; Retrieve orig r25 and save it with rest of callee_regs
 	ld	r12, [r12, PT_user_r25]
 	PUSH	r12
 #else
 	PUSH	r25
 #endif

 .endm

 /*--------------------------------------------------------------
  * Save kernel Mode callee regs at the time of Contect Switch.
  *
  * Special handling for r25 if used for caching Task Pointer.
  * Kernel simply skips saving it since it will be loaded with
  * incoming task pointer anyways
  *-------------------------------------------------------------*/
 .macro SAVE_CALLEE_SAVED_KERNEL

 	SAVE_R13_TO_R24

 #ifdef CONFIG_ARC_CURR_IN_REG
 	sub     sp, sp, 4
 #else
 	PUSH	r25
 #endif
 .endm

 /*--------------------------------------------------------------
  * Opposite of SAVE_CALLEE_SAVED_KERNEL
  *-------------------------------------------------------------*/
 .macro RESTORE_CALLEE_SAVED_KERNEL

 #ifdef CONFIG_ARC_CURR_IN_REG
 	add     sp, sp, 4  /* skip usual r25 placeholder */
 #else
 	POP	r25
 #endif
 	RESTORE_R24_TO_R13
 .endm

 /*--------------------------------------------------------------
  * Opposite of SAVE_CALLEE_SAVED_USER
  *
  * ptrace tracer or unaligned-access fixup might have changed a user mode
  * callee reg which is saved back to usual r25 storage location
  *-------------------------------------------------------------*/
 .macro RESTORE_CALLEE_SAVED_USER

 #ifdef CONFIG_ARC_CURR_IN_REG
 	POP	r12
 #else
 	POP	r25
 #endif
 	RESTORE_R24_TO_R13

 	; SP is back to start of pt_regs
 #ifdef CONFIG_ARC_CURR_IN_REG
 	st	r12, [sp, PT_user_r25]
 #endif
 .endm

 /*--------------------------------------------------------------
  * Super FAST Restore callee saved regs by simply re-adjusting SP
  *-------------------------------------------------------------*/
 .macro DISCARD_CALLEE_SAVED_USER
 	add     sp, sp, SZ_CALLEE_REGS
 .endm

 /*-------------------------------------------------------------
  * given a tsk struct, get to the base of it's kernel mode stack
  * tsk->thread_info is really a PAGE, whose bottom hoists stack
  * which grows upwards towards thread_info
  *------------------------------------------------------------*/

 .macro GET_TSK_STACK_BASE tsk, out

 	/* Get task->thread_info (this is essentially start of a PAGE) */
 	ld  \out, [\tsk, TASK_THREAD_INFO]

 	/* Go to end of page where stack begins (grows upwards) */
 	add2 \out, \out, (THREAD_SIZE)/4

 .endm

 /*
  * @reg [OUT] thread_info->flags of "current"
  */
 .macro GET_CURR_THR_INFO_FLAGS  reg
 	GET_CURR_THR_INFO_FROM_SP  \reg
 	ld  \reg, [\reg, THREAD_INFO_FLAGS]
 .endm

 #ifdef CONFIG_SMP

 /*-------------------------------------------------
  * Retrieve the current running task on this CPU
  * 1. Determine curr CPU id.
  * 2. Use it to index into _current_task[ ]
  */
 .macro  GET_CURR_TASK_ON_CPU   reg
 	GET_CPU_ID  \reg
 	ld.as  \reg, [@_current_task, \reg]
 .endm

 /*-------------------------------------------------
  * Save a new task as the "current" task on this CPU
  * 1. Determine curr CPU id.
  * 2. Use it to index into _current_task[ ]
  *
  * Coded differently than GET_CURR_TASK_ON_CPU (which uses LD.AS)
  * because ST r0, [r1, offset] can ONLY have s9 @offset
  * while   LD can take s9 (4 byte insn) or LIMM (8 byte insn)
  */

 .macro  SET_CURR_TASK_ON_CPU    tsk, tmp
 	GET_CPU_ID  \tmp
 	add2 \tmp, @_current_task, \tmp
 	st   \tsk, [\tmp]
 #ifdef CONFIG_ARC_CURR_IN_REG
 	mov r25, \tsk
 #endif

 .endm


 #else   /* Uniprocessor implementation of macros */

 .macro  GET_CURR_TASK_ON_CPU    reg
 	ld  \reg, [@_current_task]
 .endm

 .macro  SET_CURR_TASK_ON_CPU    tsk, tmp
 	st  \tsk, [@_current_task]
 #ifdef CONFIG_ARC_CURR_IN_REG
 	mov r25, \tsk
 #endif
 .endm

 #endif /* SMP / UNI */

 /* ------------------------------------------------------------------
  * Get the ptr to some field of Current Task at @off in task struct
  *  -Uses r25 for Current task ptr if that is enabled
  */

 #ifdef CONFIG_ARC_CURR_IN_REG

 .macro GET_CURR_TASK_FIELD_PTR  off,  reg
 	add \reg, r25, \off
 .endm

 #else

 .macro GET_CURR_TASK_FIELD_PTR  off,  reg
 	GET_CURR_TASK_ON_CPU  \reg
 	add \reg, \reg, \off
 .endm

 #endif	/* CONFIG_ARC_CURR_IN_REG */

 #endif  /* __ASM_ARC_ENTRY_H */
	/* SPDX-License-Identifier: GPL-2.0-only */
	/*
	* Copyright (C) 2014-15 Synopsys, Inc. (www.synopsys.com)
	* Copyright (C) 2004, 2007-2010, 2011-2012 Synopsys, Inc. (www.synopsys.com)
	*/

	#ifndef __ASM_ARC_ENTRY_H
	#define __ASM_ARC_ENTRY_H

	#include <asm/unistd.h> /* For NR_syscalls defination */
	#include <asm/arcregs.h>
	#include <asm/ptrace.h>
	#include <asm/processor.h> /* For VMALLOC_START */
	#include <asm/mmu.h>

	#ifdef CONFIG_ISA_ARCOMPACT
	#include <asm/entry-compact.h> /* ISA specific bits */
	#else
	#include <asm/entry-arcv2.h>
	#endif

	/* Note on the LD/ST addr modes with addr reg wback
	*
	* LD.a same as LD.aw
	*
	* LD.a reg1, [reg2, x] => Pre Incr
	* Eff Addr for load = [reg2 + x]
	*
	* LD.ab reg1, [reg2, x] => Post Incr
	* Eff Addr for load = [reg2]
	*/

	.macro PUSH reg
	st.a \reg, [sp, -4]
	.endm

	.macro PUSHAX aux
	lr r9, [\aux]
	PUSH r9
	.endm

	.macro POP reg
	ld.ab \reg, [sp, 4]
	.endm

	.macro POPAX aux
	POP r9
	sr r9, [\aux]
	.endm

	/*--------------------------------------------------------------
	* Helpers to save/restore Scratch Regs:
	* used by Interrupt/Exception Prologue/Epilogue
	-------------------------------------------------------------/
	.macro SAVE_R0_TO_R12
	PUSH r0
	PUSH r1
	PUSH r2
	PUSH r3
	PUSH r4
	PUSH r5
	PUSH r6
	PUSH r7
	PUSH r8
	PUSH r9
	PUSH r10
	PUSH r11
	PUSH r12
	.endm

	.macro RESTORE_R12_TO_R0
	POP r12
	POP r11
	POP r10
	POP r9
	POP r8
	POP r7
	POP r6
	POP r5
	POP r4
	POP r3
	POP r2
	POP r1
	POP r0

	.endm

	/*--------------------------------------------------------------
	* Helpers to save/restore callee-saved regs:
	* used by several macros below
	-------------------------------------------------------------/
	.macro SAVE_R13_TO_R24
	PUSH r13
	PUSH r14
	PUSH r15
	PUSH r16
	PUSH r17
	PUSH r18
	PUSH r19
	PUSH r20
	PUSH r21
	PUSH r22
	PUSH r23
	PUSH r24
	.endm

	.macro RESTORE_R24_TO_R13
	POP r24
	POP r23
	POP r22
	POP r21
	POP r20
	POP r19
	POP r18
	POP r17
	POP r16
	POP r15
	POP r14
	POP r13
	.endm

	/*--------------------------------------------------------------
	* Collect User Mode callee regs as struct callee_regs - needed by
	* fork/do_signal/unaligned-access-emulation.
	* (By default only scratch regs are saved on entry to kernel)
	*
	* Special handling for r25 if used for caching Task Pointer.
	* It would have been saved in task->thread.user_r25 already, but to keep
	* the interface same it is copied into regular r25 placeholder in
	* struct callee_regs.
	-------------------------------------------------------------/
	.macro SAVE_CALLEE_SAVED_USER

	mov r12, sp ; save SP as ref to pt_regs
	SAVE_R13_TO_R24

	#ifdef CONFIG_ARC_CURR_IN_REG
	; Retrieve orig r25 and save it with rest of callee_regs
	ld r12, [r12, PT_user_r25]
	PUSH r12
	#else
	PUSH r25
	#endif

	.endm

	/*--------------------------------------------------------------
	* Save kernel Mode callee regs at the time of Contect Switch.
	*
	* Special handling for r25 if used for caching Task Pointer.
	* Kernel simply skips saving it since it will be loaded with
	* incoming task pointer anyways
	-------------------------------------------------------------/
	.macro SAVE_CALLEE_SAVED_KERNEL

	SAVE_R13_TO_R24

	#ifdef CONFIG_ARC_CURR_IN_REG
	sub sp, sp, 4
	#else
	PUSH r25
	#endif
	.endm

	/*--------------------------------------------------------------
	* Opposite of SAVE_CALLEE_SAVED_KERNEL
	-------------------------------------------------------------/
	.macro RESTORE_CALLEE_SAVED_KERNEL

	#ifdef CONFIG_ARC_CURR_IN_REG
	add sp, sp, 4 /* skip usual r25 placeholder */
	#else
	POP r25
	#endif
	RESTORE_R24_TO_R13
	.endm

	/*--------------------------------------------------------------
	* Opposite of SAVE_CALLEE_SAVED_USER
	*
	* ptrace tracer or unaligned-access fixup might have changed a user mode
	* callee reg which is saved back to usual r25 storage location
	-------------------------------------------------------------/
	.macro RESTORE_CALLEE_SAVED_USER

	#ifdef CONFIG_ARC_CURR_IN_REG
	POP r12
	#else
	POP r25
	#endif
	RESTORE_R24_TO_R13

	; SP is back to start of pt_regs
	#ifdef CONFIG_ARC_CURR_IN_REG
	st r12, [sp, PT_user_r25]
	#endif
	.endm

	/*--------------------------------------------------------------
	* Super FAST Restore callee saved regs by simply re-adjusting SP
	-------------------------------------------------------------/
	.macro DISCARD_CALLEE_SAVED_USER
	add sp, sp, SZ_CALLEE_REGS
	.endm

	/*-------------------------------------------------------------
	* given a tsk struct, get to the base of it's kernel mode stack
	* tsk->thread_info is really a PAGE, whose bottom hoists stack
	* which grows upwards towards thread_info
	------------------------------------------------------------/

	.macro GET_TSK_STACK_BASE tsk, out

	/* Get task->thread_info (this is essentially start of a PAGE) */
	ld \out, [\tsk, TASK_THREAD_INFO]

	/* Go to end of page where stack begins (grows upwards) */
	add2 \out, \out, (THREAD_SIZE)/4

	.endm

	/*
	* @reg [OUT] thread_info->flags of "current"
	*/
	.macro GET_CURR_THR_INFO_FLAGS reg
	GET_CURR_THR_INFO_FROM_SP \reg
	ld \reg, [\reg, THREAD_INFO_FLAGS]
	.endm

	#ifdef CONFIG_SMP

	/*-------------------------------------------------
	* Retrieve the current running task on this CPU
	* 1. Determine curr CPU id.
	* 2. Use it to index into _current_task[ ]
	*/
	.macro GET_CURR_TASK_ON_CPU reg
	GET_CPU_ID \reg
	ld.as \reg, [@_current_task, \reg]
	.endm

	/*-------------------------------------------------
	* Save a new task as the "current" task on this CPU
	* 1. Determine curr CPU id.
	* 2. Use it to index into _current_task[ ]
	*
	* Coded differently than GET_CURR_TASK_ON_CPU (which uses LD.AS)
	* because ST r0, [r1, offset] can ONLY have s9 @offset
	* while LD can take s9 (4 byte insn) or LIMM (8 byte insn)
	*/

	.macro SET_CURR_TASK_ON_CPU tsk, tmp
	GET_CPU_ID \tmp
	add2 \tmp, @_current_task, \tmp
	st \tsk, [\tmp]
	#ifdef CONFIG_ARC_CURR_IN_REG
	mov r25, \tsk
	#endif

	.endm


	#else /* Uniprocessor implementation of macros */

	.macro GET_CURR_TASK_ON_CPU reg
	ld \reg, [@_current_task]
	.endm

	.macro SET_CURR_TASK_ON_CPU tsk, tmp
	st \tsk, [@_current_task]
	#ifdef CONFIG_ARC_CURR_IN_REG
	mov r25, \tsk
	#endif
	.endm

	#endif /* SMP / UNI */

	/* ------------------------------------------------------------------
	* Get the ptr to some field of Current Task at @off in task struct
	* -Uses r25 for Current task ptr if that is enabled
	*/

	#ifdef CONFIG_ARC_CURR_IN_REG

	.macro GET_CURR_TASK_FIELD_PTR off, reg
	add \reg, r25, \off
	.endm

	#else

	.macro GET_CURR_TASK_FIELD_PTR off, reg
	GET_CURR_TASK_ON_CPU \reg
	add \reg, \reg, \off
	.endm

	#endif /* CONFIG_ARC_CURR_IN_REG */

	#endif /* __ASM_ARC_ENTRY_H */