/* * This file contains the power_save function for 6xx & 7xxx CPUs * rewritten in assembler * * Warning ! This code assumes that if your machine has a 750fx * it will have PLL 1 set to low speed mode (used during NAP/DOZE). * if this is not the case some additional changes will have to * be done to check a runtime var (a bit like powersave-nap) * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public License * as published by the Free Software Foundation; either version * 2 of the License, or (at your option) any later version. */ #include #include #include #include #include #include #include "ppc_defs.h" #undef DEBUG .text /* * Init idle, called at early CPU setup time from head.S for each CPU * Make sure no rest of NAP mode remains in HID0, save default * values for some CPU specific registers. Called with r24 * containing CPU number and r3 reloc offset */ .globl init_idle_6xx init_idle_6xx: BEGIN_FTR_SECTION mfspr r4,SPRN_HID0 rlwinm r4,r4,0,10,8 /* Clear NAP */ mtspr SPRN_HID0, r4 b 1f END_FTR_SECTION_IFSET(CPU_FTR_CAN_NAP) blr 1: slwi r5,r24,2 add r5,r5,r3 BEGIN_FTR_SECTION mfspr r4,SPRN_MSSCR0 addis r6,r5, nap_save_msscr0@ha stw r4,nap_save_msscr0@l(r6) END_FTR_SECTION_IFSET(CPU_FTR_NAP_DISABLE_L2_PR) BEGIN_FTR_SECTION mfspr r4,SPRN_HID1 addis r6,r5,nap_save_hid1@ha stw r4,nap_save_hid1@l(r6) END_FTR_SECTION_IFSET(CPU_FTR_750FX) blr /* * Here is the power_save function. This could eventually be * split into several functions & changing the function pointer * depending on the various features. */ .globl power_save power_save: /* Check if we can nap or doze, put HID0 mask in r3 */ lis r3, 0 BEGIN_FTR_SECTION lis r3,HID0_DOZE@h END_FTR_SECTION_IFSET(CPU_FTR_CAN_DOZE) BEGIN_FTR_SECTION /* We must dynamically check for the NAP feature as it * can be cleared by CPU init after the fixups are done */ lis r4,cur_cpu_spec@ha lwz r4,cur_cpu_spec@l(r4) lwz r4,CPU_SPEC_FEATURES(r4) andi. r0,r4,CPU_FTR_CAN_NAP beq 1f /* Now check if user or arch enabled NAP mode */ lis r4,powersave_nap@ha lwz r4,powersave_nap@l(r4) cmpi 0,r4,0 beq 1f lis r3,HID0_NAP@h 1: END_FTR_SECTION_IFSET(CPU_FTR_CAN_NAP) cmpi 0,r3,0 beqlr /* Clear MSR:EE */ mfmsr r7 rlwinm r0,r7,0,17,15 mtmsr r0 /* Check current->need_resched */ lwz r4,NEED_RESCHED(r2) cmpi 0,r4,0 beq+ 1f mtmsr r7 /* out of line this ? */ blr 1: /* Some pre-nap cleanups needed on some CPUs */ andis. r0,r3,HID0_NAP@h beq 2f BEGIN_FTR_SECTION /* Disable L2 prefetch on some 745x and try to ensure * L2 prefetch engines are idle. As explained by errata * text, we can't be sure they are, we just hope very hard * that well be enough (sic !). At least I noticed Apple * doesn't even bother doing the dcbf's here... */ mfspr r4,SPRN_MSSCR0 rlwinm r4,r4,0,0,29 sync mtspr SPRN_MSSCR0,r4 sync isync lis r4,KERNELBASE@h dcbf 0,r4 dcbf 0,r4 dcbf 0,r4 dcbf 0,r4 END_FTR_SECTION_IFSET(CPU_FTR_NAP_DISABLE_L2_PR) #ifdef DEBUG lis r6,nap_enter_count@ha lwz r4,nap_enter_count@l(r6) addi r4,r4,1 stw r4,nap_enter_count@l(r6) #endif 2: BEGIN_FTR_SECTION /* Go to low speed mode on some 750FX */ lis r4,powersave_lowspeed@ha lwz r4,powersave_lowspeed@l(r4) cmpi 0,r4,0 beq 1f mfspr r4,SPRN_HID1 oris r4,r4,0x0001 mtspr SPRN_HID1,r4 1: END_FTR_SECTION_IFSET(CPU_FTR_750FX) /* Go to NAP or DOZE now */ mfspr r4,SPRN_HID0 lis r5,(HID0_NAP|HID0_SLEEP)@h BEGIN_FTR_SECTION oris r5,r5,HID0_DOZE@h END_FTR_SECTION_IFSET(CPU_FTR_CAN_DOZE) andc r4,r4,r5 or r4,r4,r3 BEGIN_FTR_SECTION oris r4,r4,HID0_DPM@h /* that should be done once for all */ END_FTR_SECTION_IFCLR(CPU_FTR_NO_DPM) mtspr SPRN_HID0,r4 BEGIN_FTR_SECTION DSSALL sync END_FTR_SECTION_IFSET(CPU_FTR_ALTIVEC) ori r7,r7,MSR_EE /* Could be ommited (already set) */ oris r7,r7,MSR_POW@h sync isync mtmsr r7 .globl power_save_6xx_ret power_save_6xx_ret: isync sync blr /* * Return from NAP/DOZE mode, restore some CPU specific registers, * we are called with DR/IR still off and r2 containing physical * address of current. */ .globl power_save_6xx_restore power_save_6xx_restore: mfspr r22,SPRN_HID0 rlwinm. r22,r22,0,10,8 /* Clear NAP & copy NAP bit !state to cr1 EQ */ cror 4*cr1+eq,4*cr0+eq,4*cr0+eq BEGIN_FTR_SECTION rlwinm r22,r22,0,9,7 /* Clear DOZE */ END_FTR_SECTION_IFSET(CPU_FTR_CAN_DOZE) mtspr SPRN_HID0, r22 #ifdef DEBUG beq cr1,1f lis r22,(nap_return_count-KERNELBASE)@ha lwz r24,nap_return_count@l(r22) addi r24,r24,1 stw r24,nap_return_count@l(r22) 1: #endif lwz r24,PROCESSOR(r2) slwi r24,r24,2 /* Todo make sure all these are in the same page * and load r22 (@ha part + CPU offset) only once */ BEGIN_FTR_SECTION beq cr1,1f addis r22,r24,(nap_save_msscr0-KERNELBASE)@ha lwz r22,nap_save_msscr0@l(r22) mtspr SPRN_MSSCR0, r22 sync isync 1: END_FTR_SECTION_IFSET(CPU_FTR_NAP_DISABLE_L2_PR) BEGIN_FTR_SECTION addis r22,r24,(nap_save_hid1-KERNELBASE)@ha lwz r22,nap_save_hid1@l(r22) mtspr SPRN_HID1, r22 END_FTR_SECTION_IFSET(CPU_FTR_750FX) b transfer_to_handler_cont .data .globl nap_save_msscr0 nap_save_msscr0: .space 4*NR_CPUS .globl nap_save_hid1 nap_save_hid1: .space 4*NR_CPUS #ifdef DEBUG .globl nap_enter_count nap_enter_count: .space 4 .globl nap_return_count nap_return_count: .space 4 #endif