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 Book3E 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 #ifdef CONFIG_PPC64 20 21 .macro BOOK3E_IDLE name loop 22 _GLOBAL(\name) 23 /* Save LR for later */ 24 mflr r0 25 std r0,16(r1) 26 27 /* Hard disable interrupts */ 28 wrteei 0 29 30 /* Now check if an interrupt came in while we were soft disabled 31 * since we may otherwise lose it (doorbells etc...). 32 */ 33 lbz r3,PACAIRQHAPPENED(r13) 34 cmpwi cr0,r3,0 35 bne 2f 36 37 /* Now we are going to mark ourselves as soft and hard enabled in 38 * order to be able to take interrupts while asleep. We inform lockdep 39 * of that. We don't actually turn interrupts on just yet tho. 40 */ 41 #ifdef CONFIG_TRACE_IRQFLAGS 42 stdu r1,-128(r1) 43 bl trace_hardirqs_on 44 addi r1,r1,128 45 #endif 46 li r0,IRQS_ENABLED 47 stb r0,PACAIRQSOFTMASK(r13) 48 49 /* Interrupts will make use return to LR, so get something we want 50 * in there 51 */ 52 bl 1f 53 54 /* And return (interrupts are on) */ 55 ld r0,16(r1) 56 mtlr r0 57 blr 58 59 1: /* Let's set the _TLF_NAPPING flag so interrupts make us return 60 * to the right spot 61 */ 62 ld r11, PACACURRENT(r13) 63 ld r10,TI_LOCAL_FLAGS(r11) 64 ori r10,r10,_TLF_NAPPING 65 std r10,TI_LOCAL_FLAGS(r11) 66 67 /* We can now re-enable hard interrupts and go to sleep */ 68 wrteei 1 69 \loop 70 71 2: 72 lbz r10,PACAIRQHAPPENED(r13) 73 ori r10,r10,PACA_IRQ_HARD_DIS 74 stb r10,PACAIRQHAPPENED(r13) 75 blr 76 .endm 77 78 .macro BOOK3E_IDLE_LOOP 79 1: 80 PPC_WAIT(0) 81 b 1b 82 .endm 83 84 /* epapr_ev_idle_start below is patched with the proper hcall 85 opcodes during kernel initialization */ 86 .macro EPAPR_EV_IDLE_LOOP 87 idle_loop: 88 LOAD_REG_IMMEDIATE(r11, EV_HCALL_TOKEN(EV_IDLE)) 89 90 .global epapr_ev_idle_start 91 epapr_ev_idle_start: 92 li r3, -1 93 nop 94 nop 95 nop 96 b idle_loop 97 .endm 98 99 BOOK3E_IDLE epapr_ev_idle EPAPR_EV_IDLE_LOOP 100 101 BOOK3E_IDLE book3e_idle BOOK3E_IDLE_LOOP 102 103 #endif /* CONFIG_PPC64 */ 104