1/* SPDX-License-Identifier: GPL-2.0-or-later */ 2/* 3 * Copyright 2010 IBM Corp, Benjamin Herrenschmidt <benh@kernel.crashing.org> 4 * 5 * Generic idle routine for 64 bits e500 processors 6 */ 7 8#include <linux/threads.h> 9#include <asm/reg.h> 10#include <asm/ppc_asm.h> 11#include <asm/asm-offsets.h> 12#include <asm/ppc-opcode.h> 13#include <asm/processor.h> 14#include <asm/thread_info.h> 15#include <asm/epapr_hcalls.h> 16#include <asm/hw_irq.h> 17 18/* 64-bit version only for now */ 19.macro BOOK3E_IDLE name loop 20_GLOBAL(\name) 21 /* Save LR for later */ 22 mflr r0 23 std r0,16(r1) 24 25 /* Hard disable interrupts */ 26 wrteei 0 27 28 /* Now check if an interrupt came in while we were soft disabled 29 * since we may otherwise lose it (doorbells etc...). 30 */ 31 lbz r3,PACAIRQHAPPENED(r13) 32 cmpwi cr0,r3,0 33 bne 2f 34 35 /* Now we are going to mark ourselves as soft and hard enabled in 36 * order to be able to take interrupts while asleep. We inform lockdep 37 * of that. We don't actually turn interrupts on just yet tho. 38 */ 39#ifdef CONFIG_TRACE_IRQFLAGS 40 stdu r1,-128(r1) 41 bl trace_hardirqs_on 42 addi r1,r1,128 43#endif 44 li r0,IRQS_ENABLED 45 stb r0,PACAIRQSOFTMASK(r13) 46 47 /* Interrupts will make use return to LR, so get something we want 48 * in there 49 */ 50 bl 1f 51 52 /* And return (interrupts are on) */ 53 ld r0,16(r1) 54 mtlr r0 55 blr 56 571: /* Let's set the _TLF_NAPPING flag so interrupts make us return 58 * to the right spot 59 */ 60 ld r11, PACACURRENT(r13) 61 ld r10,TI_LOCAL_FLAGS(r11) 62 ori r10,r10,_TLF_NAPPING 63 std r10,TI_LOCAL_FLAGS(r11) 64 65 /* We can now re-enable hard interrupts and go to sleep */ 66 wrteei 1 67 \loop 68 692: 70 lbz r10,PACAIRQHAPPENED(r13) 71 ori r10,r10,PACA_IRQ_HARD_DIS 72 stb r10,PACAIRQHAPPENED(r13) 73 blr 74.endm 75 76.macro BOOK3E_IDLE_LOOP 771: 78 PPC_WAIT_v203 79 b 1b 80.endm 81 82/* epapr_ev_idle_start below is patched with the proper hcall 83 opcodes during kernel initialization */ 84.macro EPAPR_EV_IDLE_LOOP 85idle_loop: 86 LOAD_REG_IMMEDIATE(r11, EV_HCALL_TOKEN(EV_IDLE)) 87 88.global epapr_ev_idle_start 89epapr_ev_idle_start: 90 li r3, -1 91 nop 92 nop 93 nop 94 b idle_loop 95.endm 96 97BOOK3E_IDLE epapr_ev_idle EPAPR_EV_IDLE_LOOP 98 99BOOK3E_IDLE e500_idle BOOK3E_IDLE_LOOP 100