| Kyle Swenson | 8d8f654 | 2021-03-15 11:02:55 -0600 | [diff] [blame^] | 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 | |
| 62 | 1: /* 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 |
| 77 | 1: |
| 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 |
| 85 | idle_loop: |
| 86 | LOAD_REG_IMMEDIATE(r11, EV_HCALL_TOKEN(EV_IDLE)) |
| 87 | |
| 88 | .global epapr_ev_idle_start |
| 89 | epapr_ev_idle_start: |
| 90 | li r3, -1 |
| 91 | nop |
| 92 | nop |
| 93 | nop |
| 94 | b idle_loop |
| 95 | .endm |
| 96 | |
| 97 | BOOK3E_IDLE epapr_ev_idle EPAPR_EV_IDLE_LOOP |
| 98 | |
| 99 | BOOK3E_IDLE book3e_idle BOOK3E_IDLE_LOOP |
| 100 | |
| 101 | #endif /* CONFIG_PPC64 */ |