From 49f2ec91e14ce9bb20fdac88a38243129f3261c3 Mon Sep 17 00:00:00 2001 From: Ralf Baechle Date: Tue, 21 May 2013 10:53:37 +0200 Subject: [PATCH] MIPS: Consolidate idle loop / WAIT instruction support in a single file. Signed-off-by: Ralf Baechle --- arch/mips/kernel/Makefile | 2 +- arch/mips/kernel/cpu-probe.c | 198 ------------------------------ arch/mips/kernel/idle.c | 232 +++++++++++++++++++++++++++++++++++ arch/mips/kernel/process.c | 13 -- 4 files changed, 233 insertions(+), 212 deletions(-) create mode 100644 arch/mips/kernel/idle.c diff --git a/arch/mips/kernel/Makefile b/arch/mips/kernel/Makefile index 6ad9e04bdf62..423d871a946b 100644 --- a/arch/mips/kernel/Makefile +++ b/arch/mips/kernel/Makefile @@ -4,7 +4,7 @@ extra-y := head.o vmlinux.lds -obj-y += cpu-probe.o branch.o entry.o genex.o irq.o process.o \ +obj-y += cpu-probe.o branch.o entry.o genex.o idle.o irq.o process.o \ prom.o ptrace.o reset.o setup.o signal.o syscall.o \ time.o topology.o traps.o unaligned.o watch.o vdso.o diff --git a/arch/mips/kernel/cpu-probe.c b/arch/mips/kernel/cpu-probe.c index 4bbffdb9024f..c6568bf4b1b0 100644 --- a/arch/mips/kernel/cpu-probe.c +++ b/arch/mips/kernel/cpu-probe.c @@ -27,105 +27,6 @@ #include #include -/* - * Not all of the MIPS CPUs have the "wait" instruction available. Moreover, - * the implementation of the "wait" feature differs between CPU families. This - * points to the function that implements CPU specific wait. - * The wait instruction stops the pipeline and reduces the power consumption of - * the CPU very much. - */ -void (*cpu_wait)(void); -EXPORT_SYMBOL(cpu_wait); - -static void r3081_wait(void) -{ - unsigned long cfg = read_c0_conf(); - write_c0_conf(cfg | R30XX_CONF_HALT); -} - -static void r39xx_wait(void) -{ - local_irq_disable(); - if (!need_resched()) - write_c0_conf(read_c0_conf() | TX39_CONF_HALT); - local_irq_enable(); -} - -extern void r4k_wait(void); - -/* - * This variant is preferable as it allows testing need_resched and going to - * sleep depending on the outcome atomically. Unfortunately the "It is - * implementation-dependent whether the pipeline restarts when a non-enabled - * interrupt is requested" restriction in the MIPS32/MIPS64 architecture makes - * using this version a gamble. - */ -void r4k_wait_irqoff(void) -{ - local_irq_disable(); - if (!need_resched()) - __asm__(" .set push \n" - " .set mips3 \n" - " wait \n" - " .set pop \n"); - local_irq_enable(); - __asm__(" .globl __pastwait \n" - "__pastwait: \n"); -} - -/* - * The RM7000 variant has to handle erratum 38. The workaround is to not - * have any pending stores when the WAIT instruction is executed. - */ -static void rm7k_wait_irqoff(void) -{ - local_irq_disable(); - if (!need_resched()) - __asm__( - " .set push \n" - " .set mips3 \n" - " .set noat \n" - " mfc0 $1, $12 \n" - " sync \n" - " mtc0 $1, $12 # stalls until W stage \n" - " wait \n" - " mtc0 $1, $12 # stalls until W stage \n" - " .set pop \n"); - local_irq_enable(); -} - -/* - * The Au1xxx wait is available only if using 32khz counter or - * external timer source, but specifically not CP0 Counter. - * alchemy/common/time.c may override cpu_wait! - */ -static void au1k_wait(void) -{ - __asm__(" .set mips3 \n" - " cache 0x14, 0(%0) \n" - " cache 0x14, 32(%0) \n" - " sync \n" - " nop \n" - " wait \n" - " nop \n" - " nop \n" - " nop \n" - " nop \n" - " .set mips0 \n" - : : "r" (au1k_wait)); -} - -static int __initdata nowait; - -static int __init wait_disable(char *s) -{ - nowait = 1; - - return 1; -} - -__setup("nowait", wait_disable); - static int __cpuinitdata mips_fpu_disabled; static int __init fpu_disable(char *s) @@ -150,105 +51,6 @@ static int __init dsp_disable(char *s) __setup("nodsp", dsp_disable); -void __init check_wait(void) -{ - struct cpuinfo_mips *c = ¤t_cpu_data; - - if (nowait) { - printk("Wait instruction disabled.\n"); - return; - } - - switch (c->cputype) { - case CPU_R3081: - case CPU_R3081E: - cpu_wait = r3081_wait; - break; - case CPU_TX3927: - cpu_wait = r39xx_wait; - break; - case CPU_R4200: -/* case CPU_R4300: */ - case CPU_R4600: - case CPU_R4640: - case CPU_R4650: - case CPU_R4700: - case CPU_R5000: - case CPU_R5500: - case CPU_NEVADA: - case CPU_4KC: - case CPU_4KEC: - case CPU_4KSC: - case CPU_5KC: - case CPU_25KF: - case CPU_PR4450: - case CPU_BMIPS3300: - case CPU_BMIPS4350: - case CPU_BMIPS4380: - case CPU_BMIPS5000: - case CPU_CAVIUM_OCTEON: - case CPU_CAVIUM_OCTEON_PLUS: - case CPU_CAVIUM_OCTEON2: - case CPU_JZRISC: - case CPU_LOONGSON1: - case CPU_XLR: - case CPU_XLP: - cpu_wait = r4k_wait; - break; - - case CPU_RM7000: - cpu_wait = rm7k_wait_irqoff; - break; - - case CPU_M14KC: - case CPU_M14KEC: - case CPU_24K: - case CPU_34K: - case CPU_1004K: - cpu_wait = r4k_wait; - if (read_c0_config7() & MIPS_CONF7_WII) - cpu_wait = r4k_wait_irqoff; - break; - - case CPU_74K: - cpu_wait = r4k_wait; - if ((c->processor_id & 0xff) >= PRID_REV_ENCODE_332(2, 1, 0)) - cpu_wait = r4k_wait_irqoff; - break; - - case CPU_TX49XX: - cpu_wait = r4k_wait_irqoff; - break; - case CPU_ALCHEMY: - cpu_wait = au1k_wait; - break; - case CPU_20KC: - /* - * WAIT on Rev1.0 has E1, E2, E3 and E16. - * WAIT on Rev2.0 and Rev3.0 has E16. - * Rev3.1 WAIT is nop, why bother - */ - if ((c->processor_id & 0xff) <= 0x64) - break; - - /* - * Another rev is incremeting c0_count at a reduced clock - * rate while in WAIT mode. So we basically have the choice - * between using the cp0 timer as clocksource or avoiding - * the WAIT instruction. Until more details are known, - * disable the use of WAIT for 20Kc entirely. - cpu_wait = r4k_wait; - */ - break; - case CPU_RM9000: - if ((c->processor_id & 0x00ff) >= 0x40) - cpu_wait = r4k_wait; - break; - default: - break; - } -} - static inline void check_errata(void) { struct cpuinfo_mips *c = ¤t_cpu_data; diff --git a/arch/mips/kernel/idle.c b/arch/mips/kernel/idle.c new file mode 100644 index 000000000000..1e9d9383d49f --- /dev/null +++ b/arch/mips/kernel/idle.c @@ -0,0 +1,232 @@ +/* + * MIPS idle loop and WAIT instruction support. + * + * Copyright (C) xxxx the Anonymous + * Copyright (C) 1994 - 2006 Ralf Baechle + * Copyright (C) 2003, 2004 Maciej W. Rozycki + * Copyright (C) 2001, 2004, 2011, 2012 MIPS Technologies, Inc. + * + * 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 + +/* + * Not all of the MIPS CPUs have the "wait" instruction available. Moreover, + * the implementation of the "wait" feature differs between CPU families. This + * points to the function that implements CPU specific wait. + * The wait instruction stops the pipeline and reduces the power consumption of + * the CPU very much. + */ +void (*cpu_wait)(void); +EXPORT_SYMBOL(cpu_wait); + +static void r3081_wait(void) +{ + unsigned long cfg = read_c0_conf(); + write_c0_conf(cfg | R30XX_CONF_HALT); +} + +static void r39xx_wait(void) +{ + local_irq_disable(); + if (!need_resched()) + write_c0_conf(read_c0_conf() | TX39_CONF_HALT); + local_irq_enable(); +} + +extern void r4k_wait(void); + +/* + * This variant is preferable as it allows testing need_resched and going to + * sleep depending on the outcome atomically. Unfortunately the "It is + * implementation-dependent whether the pipeline restarts when a non-enabled + * interrupt is requested" restriction in the MIPS32/MIPS64 architecture makes + * using this version a gamble. + */ +void r4k_wait_irqoff(void) +{ + local_irq_disable(); + if (!need_resched()) + __asm__(" .set push \n" + " .set mips3 \n" + " wait \n" + " .set pop \n"); + local_irq_enable(); + __asm__(" .globl __pastwait \n" + "__pastwait: \n"); +} + +/* + * The RM7000 variant has to handle erratum 38. The workaround is to not + * have any pending stores when the WAIT instruction is executed. + */ +static void rm7k_wait_irqoff(void) +{ + local_irq_disable(); + if (!need_resched()) + __asm__( + " .set push \n" + " .set mips3 \n" + " .set noat \n" + " mfc0 $1, $12 \n" + " sync \n" + " mtc0 $1, $12 # stalls until W stage \n" + " wait \n" + " mtc0 $1, $12 # stalls until W stage \n" + " .set pop \n"); + local_irq_enable(); +} + +/* + * The Au1xxx wait is available only if using 32khz counter or + * external timer source, but specifically not CP0 Counter. + * alchemy/common/time.c may override cpu_wait! + */ +static void au1k_wait(void) +{ + __asm__(" .set mips3 \n" + " cache 0x14, 0(%0) \n" + " cache 0x14, 32(%0) \n" + " sync \n" + " nop \n" + " wait \n" + " nop \n" + " nop \n" + " nop \n" + " nop \n" + " .set mips0 \n" + : : "r" (au1k_wait)); +} + +static int __initdata nowait; + +static int __init wait_disable(char *s) +{ + nowait = 1; + + return 1; +} + +__setup("nowait", wait_disable); + +void __init check_wait(void) +{ + struct cpuinfo_mips *c = ¤t_cpu_data; + + if (nowait) { + printk("Wait instruction disabled.\n"); + return; + } + + switch (c->cputype) { + case CPU_R3081: + case CPU_R3081E: + cpu_wait = r3081_wait; + break; + case CPU_TX3927: + cpu_wait = r39xx_wait; + break; + case CPU_R4200: +/* case CPU_R4300: */ + case CPU_R4600: + case CPU_R4640: + case CPU_R4650: + case CPU_R4700: + case CPU_R5000: + case CPU_R5500: + case CPU_NEVADA: + case CPU_4KC: + case CPU_4KEC: + case CPU_4KSC: + case CPU_5KC: + case CPU_25KF: + case CPU_PR4450: + case CPU_BMIPS3300: + case CPU_BMIPS4350: + case CPU_BMIPS4380: + case CPU_BMIPS5000: + case CPU_CAVIUM_OCTEON: + case CPU_CAVIUM_OCTEON_PLUS: + case CPU_CAVIUM_OCTEON2: + case CPU_JZRISC: + case CPU_LOONGSON1: + case CPU_XLR: + case CPU_XLP: + cpu_wait = r4k_wait; + break; + + case CPU_RM7000: + cpu_wait = rm7k_wait_irqoff; + break; + + case CPU_M14KC: + case CPU_M14KEC: + case CPU_24K: + case CPU_34K: + case CPU_1004K: + cpu_wait = r4k_wait; + if (read_c0_config7() & MIPS_CONF7_WII) + cpu_wait = r4k_wait_irqoff; + break; + + case CPU_74K: + cpu_wait = r4k_wait; + if ((c->processor_id & 0xff) >= PRID_REV_ENCODE_332(2, 1, 0)) + cpu_wait = r4k_wait_irqoff; + break; + + case CPU_TX49XX: + cpu_wait = r4k_wait_irqoff; + break; + case CPU_ALCHEMY: + cpu_wait = au1k_wait; + break; + case CPU_20KC: + /* + * WAIT on Rev1.0 has E1, E2, E3 and E16. + * WAIT on Rev2.0 and Rev3.0 has E16. + * Rev3.1 WAIT is nop, why bother + */ + if ((c->processor_id & 0xff) <= 0x64) + break; + + /* + * Another rev is incremeting c0_count at a reduced clock + * rate while in WAIT mode. So we basically have the choice + * between using the cp0 timer as clocksource or avoiding + * the WAIT instruction. Until more details are known, + * disable the use of WAIT for 20Kc entirely. + cpu_wait = r4k_wait; + */ + break; + case CPU_RM9000: + if ((c->processor_id & 0x00ff) >= 0x40) + cpu_wait = r4k_wait; + break; + default: + break; + } +} + +void arch_cpu_idle(void) +{ +#ifdef CONFIG_MIPS_MT_SMTC + extern void smtc_idle_loop_hook(void); + + smtc_idle_loop_hook(); +#endif + if (cpu_wait) + (*cpu_wait)(); + else + local_irq_enable(); +} diff --git a/arch/mips/kernel/process.c b/arch/mips/kernel/process.c index a682a87bcc04..c6a041d9d05d 100644 --- a/arch/mips/kernel/process.c +++ b/arch/mips/kernel/process.c @@ -51,19 +51,6 @@ void arch_cpu_idle_dead(void) } #endif -void arch_cpu_idle(void) -{ -#ifdef CONFIG_MIPS_MT_SMTC - extern void smtc_idle_loop_hook(void); - - smtc_idle_loop_hook(); -#endif - if (cpu_wait) - (*cpu_wait)(); - else - local_irq_enable(); -} - asmlinkage void ret_from_fork(void); asmlinkage void ret_from_kernel_thread(void); -- 2.20.1