1/* 2 * Copyright 2010 IBM Corp, Benjamin Herrenschmidt <benh@kernel.crashing.org> 3 * 4 * Generic idle routine for Book3E processors 5 * 6 * This program is free software; you can redistribute it and/or 7 * modify it under the terms of the GNU General Public License 8 * as published by the Free Software Foundation; either version 9 * 2 of the License, or (at your option) any later version. 10 */ 11 12#include <linux/threads.h> 13#include <asm/reg.h> 14#include <asm/ppc_asm.h> 15#include <asm/asm-offsets.h> 16#include <asm/ppc-opcode.h> 17#include <asm/processor.h> 18#include <asm/thread_info.h> 19#include <asm/epapr_hcalls.h> 20 21/* 64-bit version only for now */ 22#ifdef CONFIG_PPC64 23 24.macro BOOK3E_IDLE name loop 25_GLOBAL(\name) 26 /* Save LR for later */ 27 mflr r0 28 std r0,16(r1) 29 30 /* Hard disable interrupts */ 31 wrteei 0 32 33 /* Now check if an interrupt came in while we were soft disabled 34 * since we may otherwise lose it (doorbells etc...). 35 */ 36 lbz r3,PACAIRQHAPPENED(r13) 37 cmpwi cr0,r3,0 38 bnelr 39 40 /* Now we are going to mark ourselves as soft and hard enabled in 41 * order to be able to take interrupts while asleep. We inform lockdep 42 * of that. We don't actually turn interrupts on just yet tho. 43 */ 44#ifdef CONFIG_TRACE_IRQFLAGS 45 stdu r1,-128(r1) 46 bl trace_hardirqs_on 47 addi r1,r1,128 48#endif 49 li r0,1 50 stb r0,PACASOFTIRQEN(r13) 51 52 /* Interrupts will make use return to LR, so get something we want 53 * in there 54 */ 55 bl 1f 56 57 /* And return (interrupts are on) */ 58 ld r0,16(r1) 59 mtlr r0 60 blr 61 621: /* Let's set the _TLF_NAPPING flag so interrupts make us return 63 * to the right spot 64 */ 65 CURRENT_THREAD_INFO(r11, r1) 66 ld r10,TI_LOCAL_FLAGS(r11) 67 ori r10,r10,_TLF_NAPPING 68 std r10,TI_LOCAL_FLAGS(r11) 69 70 /* We can now re-enable hard interrupts and go to sleep */ 71 wrteei 1 72 \loop 73 74.endm 75 76.macro BOOK3E_IDLE_LOOP 771: 78 PPC_WAIT(0) 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 book3e_idle BOOK3E_IDLE_LOOP 100 101#endif /* CONFIG_PPC64 */ 102