include/asm/entry-compact.h

1 /* SPDX-License-Identifier: GPL-2.0-only */
3  * Copyright (C) 2014-15 Synopsys, Inc. (www.synopsys.com)
4  * Copyright (C) 2004, 2007-2010, 2011-2012 Synopsys, Inc. (www.synopsys.com)
7  *  Stack switching code can no longer reliably rely on the fact that
10  *  it's prologue including stack switching from user mode
13  *  -Zero Overhead Loop Context shd be cleared when entering IRQ/EXcp/Trap
20  *  -Modified CALLEE_REG save/restore macros to handle the fact that
22  *  - Defined Stack Switching Macro to be reused in all intr/excp hdlrs
23  *  - Shaved off 11 instructions from RESTORE_ALL_INT1 by using the
32 #include <asm/asm-offsets.h>
33 #include <asm/irqflags-compact.h>
36 /*--------------------------------------------------------------
39  * Entry   : r9 contains pre-IRQ/exception/trap status32
41  *           SP at the time of entry (K/U) saved @ pt_regs->sp
43  *-------------------------------------------------------------*/
51 	 * assume SP is kernel mode SP. _NO_ need to do any stack switching
58 	 * 2. L1 IRQ taken, ISR starts (CPU auto-switched to KERNEL mode)
72 	 * Above brlo alone would treat it as a valid L1-L2 scenario
75 	 * L1 prelogue ONLY i.e. ilink2 is less than a pre-set marker in
81     /*------Intr/Ecxp happened in kernel mode, SP already setup ------ */
82 	/* save it nevertheless @ pt_regs->sp for uniformity */
85 	st	sp, [sp, PT_sp - SZ_PT_REGS]
87 88: /*------Intr/Ecxp happened in user mode, "switch" stack ------ */
94 	/* save U mode SP @ pt_regs->sp */
95 	st	sp, [r9, PT_sp - SZ_PT_REGS]
102 /*------------------------------------------------------------
104  * This is to re-enable Exceptions within exception
106  *-------------------------------------------------------------*/
120 /*--------------------------------------------------------------
122  * code the rest of prolog (stack switching). This is done by stashing
123  * it to memory (non-SMP case) or SCRATCH0 Aux Reg (SMP).
125  * Before saving the full regfile - this reg is restored back, only
127  *-------------------------------------------------------------*/
136 /*--------------------------------------------------------------
138  * -Switches stack to K mode (if not already)
139  * -Saves the register file
142  *-------------------------------------------------------------*/
151 	/* ARC700 doesn't provide auto-stack switching */
154 	st.a	r0, [sp, -8]    /* orig_r0 needed for syscall (skip ECR slot) */
155 	sub	sp, sp, 4	/* skip pt_regs->sp, already saved above */
192 /*--------------------------------------------------------------
202  *-------------------------------------------------------------*/
240 				       skip pt_regs->sp, already saved above */
262 /*--------------------------------------------------------------
270  *-------------------------------------------------------------*/
292 	bic \reg, sp, (THREAD_SIZE - 1)
295 /* Get CPU-ID of this core */