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authorRalf Baechle <ralf@linux-mips.org>2013-05-21 10:53:37 +0200
committerRalf Baechle <ralf@linux-mips.org>2013-05-22 01:34:25 +0200
commit49f2ec91e14ce9bb20fdac88a38243129f3261c3 (patch)
tree91692c8fc63a0d08f71be20d6b4618468da90662 /arch
parent1a461c5bdcc815280fa5f51e3775bc05ed98af13 (diff)
MIPS: Consolidate idle loop / WAIT instruction support in a single file.
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Diffstat (limited to 'arch')
-rw-r--r--arch/mips/kernel/Makefile2
-rw-r--r--arch/mips/kernel/cpu-probe.c198
-rw-r--r--arch/mips/kernel/idle.c232
-rw-r--r--arch/mips/kernel/process.c13
4 files changed, 233 insertions, 212 deletions
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 <asm/spram.h>
#include <asm/uaccess.h>
-/*
- * 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 = &current_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 = &current_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 <linux/export.h>
+#include <linux/init.h>
+#include <linux/irqflags.h>
+#include <linux/printk.h>
+#include <linux/sched.h>
+#include <asm/cpu.h>
+#include <asm/cpu-info.h>
+#include <asm/mipsregs.h>
+
+/*
+ * 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 = &current_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);