From 948cf67c4726cca2fc57533dccadfb54d890689d Mon Sep 17 00:00:00 2001 From: Benjamin Herrenschmidt Date: Mon, 24 Jan 2011 18:42:41 +1100 Subject: [PATCH] powerpc: Add NAP mode support on Power7 in HV mode Wakeup comes from the system reset handler with a potential loss of the non-hypervisor CPU state. We save the non-volatile state on the stack and a pointer to it in the PACA, which the system reset handler uses to restore things Signed-off-by: Benjamin Herrenschmidt --- arch/powerpc/include/asm/machdep.h | 1 + arch/powerpc/include/asm/paca.h | 2 +- arch/powerpc/include/asm/ppc-opcode.h | 6 ++ arch/powerpc/kernel/Makefile | 1 + arch/powerpc/kernel/exceptions-64s.S | 30 ++++++++- arch/powerpc/kernel/idle_power7.S | 97 +++++++++++++++++++++++++++ arch/powerpc/platforms/Kconfig | 4 ++ 7 files changed, 139 insertions(+), 2 deletions(-) create mode 100644 arch/powerpc/kernel/idle_power7.S diff --git a/arch/powerpc/include/asm/machdep.h b/arch/powerpc/include/asm/machdep.h index e4f01915fbb0..493dbb38e1ba 100644 --- a/arch/powerpc/include/asm/machdep.h +++ b/arch/powerpc/include/asm/machdep.h @@ -267,6 +267,7 @@ struct machdep_calls { extern void e500_idle(void); extern void power4_idle(void); +extern void power7_idle(void); extern void ppc6xx_idle(void); extern void book3e_idle(void); diff --git a/arch/powerpc/include/asm/paca.h b/arch/powerpc/include/asm/paca.h index ec57540cd7af..f6da4f517fca 100644 --- a/arch/powerpc/include/asm/paca.h +++ b/arch/powerpc/include/asm/paca.h @@ -125,7 +125,7 @@ struct paca_struct { struct task_struct *__current; /* Pointer to current */ u64 kstack; /* Saved Kernel stack addr */ u64 stab_rr; /* stab/slb round-robin counter */ - u64 saved_r1; /* r1 save for RTAS calls */ + u64 saved_r1; /* r1 save for RTAS calls or PM */ u64 saved_msr; /* MSR saved here by enter_rtas */ u16 trap_save; /* Used when bad stack is encountered */ u8 soft_enabled; /* irq soft-enable flag */ diff --git a/arch/powerpc/include/asm/ppc-opcode.h b/arch/powerpc/include/asm/ppc-opcode.h index 1255569387b6..384a96db794a 100644 --- a/arch/powerpc/include/asm/ppc-opcode.h +++ b/arch/powerpc/include/asm/ppc-opcode.h @@ -56,6 +56,9 @@ #define PPC_INST_TLBSRX_DOT 0x7c0006a5 #define PPC_INST_XXLOR 0xf0000510 +#define PPC_INST_NAP 0x4c000364 +#define PPC_INST_SLEEP 0x4c0003a4 + /* macros to insert fields into opcodes */ #define __PPC_RA(a) (((a) & 0x1f) << 16) #define __PPC_RB(b) (((b) & 0x1f) << 11) @@ -126,4 +129,7 @@ #define XXLOR(t, a, b) stringify_in_c(.long PPC_INST_XXLOR | \ VSX_XX3((t), (a), (b))) +#define PPC_NAP stringify_in_c(.long PPC_INST_NAP) +#define PPC_SLEEP stringify_in_c(.long PPC_INST_SLEEP) + #endif /* _ASM_POWERPC_PPC_OPCODE_H */ diff --git a/arch/powerpc/kernel/Makefile b/arch/powerpc/kernel/Makefile index 7c6eb4974f25..0fd6273bb8a9 100644 --- a/arch/powerpc/kernel/Makefile +++ b/arch/powerpc/kernel/Makefile @@ -44,6 +44,7 @@ obj-$(CONFIG_PPC_BOOK3E_64) += exceptions-64e.o idle_book3e.o obj-$(CONFIG_PPC64) += vdso64/ obj-$(CONFIG_ALTIVEC) += vecemu.o obj-$(CONFIG_PPC_970_NAP) += idle_power4.o +obj-$(CONFIG_PPC_P7_NAP) += idle_power7.o obj-$(CONFIG_PPC_OF) += of_platform.o prom_parse.o obj-$(CONFIG_PPC_CLOCK) += clock.o procfs-y := proc_powerpc.o diff --git a/arch/powerpc/kernel/exceptions-64s.S b/arch/powerpc/kernel/exceptions-64s.S index e513c1d35b2a..ad06333631ac 100644 --- a/arch/powerpc/kernel/exceptions-64s.S +++ b/arch/powerpc/kernel/exceptions-64s.S @@ -37,7 +37,35 @@ .globl __start_interrupts __start_interrupts: - STD_EXCEPTION_PSERIES(0x100, 0x100, system_reset) + .globl system_reset_pSeries; +system_reset_pSeries: + HMT_MEDIUM; + DO_KVM 0x100; + SET_SCRATCH0(r13) +#ifdef CONFIG_PPC_P7_NAP +BEGIN_FTR_SECTION + /* Running native on arch 2.06 or later, check if we are + * waking up from nap. We only handle no state loss and + * supervisor state loss. We do -not- handle hypervisor + * state loss at this time. + */ + mfspr r13,SPRN_SRR1 + rlwinm r13,r13,47-31,30,31 + cmpwi cr0,r13,1 + bne 1f + b .power7_wakeup_noloss +1: cmpwi cr0,r13,2 + bne 1f + b .power7_wakeup_loss + /* Total loss of HV state is fatal, we could try to use the + * PIR to locate a PACA, then use an emergency stack etc... + * but for now, let's just stay stuck here + */ +1: cmpwi cr0,r13,3 + beq . +END_FTR_SECTION_IFSET(CPU_FTR_HVMODE_206) +#endif /* CONFIG_PPC_P7_NAP */ + EXCEPTION_PROLOG_PSERIES(PACA_EXGEN, system_reset_common, EXC_STD) . = 0x200 _machine_check_pSeries: diff --git a/arch/powerpc/kernel/idle_power7.S b/arch/powerpc/kernel/idle_power7.S new file mode 100644 index 000000000000..f8f0bc7f1d4f --- /dev/null +++ b/arch/powerpc/kernel/idle_power7.S @@ -0,0 +1,97 @@ +/* + * This file contains the power_save function for 970-family CPUs. + * + * 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 +#include + +#undef DEBUG + + .text + +_GLOBAL(power7_idle) + /* Now check if user or arch enabled NAP mode */ + LOAD_REG_ADDRBASE(r3,powersave_nap) + lwz r4,ADDROFF(powersave_nap)(r3) + cmpwi 0,r4,0 + beqlr + + /* NAP is a state loss, we create a regs frame on the + * stack, fill it up with the state we care about and + * stick a pointer to it in PACAR1. We really only + * need to save PC, some CR bits and the NV GPRs, + * but for now an interrupt frame will do. + */ + mflr r0 + std r0,16(r1) + stdu r1,-INT_FRAME_SIZE(r1) + std r0,_LINK(r1) + std r0,_NIP(r1) + +#ifndef CONFIG_SMP + /* Make sure FPU, VSX etc... are flushed as we may lose + * state when going to nap mode + */ + bl .discard_lazy_cpu_state +#endif /* CONFIG_SMP */ + + /* Hard disable interrupts */ + mfmsr r9 + rldicl r9,r9,48,1 + rotldi r9,r9,16 + mtmsrd r9,1 /* hard-disable interrupts */ + li r0,0 + stb r0,PACASOFTIRQEN(r13) /* we'll hard-enable shortly */ + stb r0,PACAHARDIRQEN(r13) + + /* Continue saving state */ + SAVE_GPR(2, r1) + SAVE_NVGPRS(r1) + mfcr r3 + std r3,_CCR(r1) + std r9,_MSR(r1) + std r1,PACAR1(r13) + + /* Magic NAP mode enter sequence */ + std r0,0(r1) + ptesync + ld r0,0(r1) +1: cmp cr0,r0,r0 + bne 1b + PPC_NAP + b . + +_GLOBAL(power7_wakeup_loss) + GET_PACA(r13) + ld r1,PACAR1(r13) + REST_NVGPRS(r1) + REST_GPR(2, r1) + ld r3,_CCR(r1) + ld r4,_MSR(r1) + ld r5,_NIP(r1) + addi r1,r1,INT_FRAME_SIZE + mtcr r3 + mtspr SPRN_SRR1,r4 + mtspr SPRN_SRR0,r5 + rfid + +_GLOBAL(power7_wakeup_noloss) + GET_PACA(r13) + ld r1,PACAR1(r13) + ld r4,_MSR(r1) + ld r5,_NIP(r1) + addi r1,r1,INT_FRAME_SIZE + mtspr SPRN_SRR1,r4 + mtspr SPRN_SRR0,r5 + rfid diff --git a/arch/powerpc/platforms/Kconfig b/arch/powerpc/platforms/Kconfig index f7b07720aa30..658ffc50493d 100644 --- a/arch/powerpc/platforms/Kconfig +++ b/arch/powerpc/platforms/Kconfig @@ -147,6 +147,10 @@ config PPC_970_NAP bool default n +config PPC_P7_NAP + bool + default n + config PPC_INDIRECT_IO bool select GENERIC_IOMAP -- 2.39.5