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authorRussell King <rmk+kernel@armlinux.org.uk>2019-01-04 14:34:46 +0000
committerRussell King <rmk+kernel@armlinux.org.uk>2019-01-04 14:34:46 +0000
commit6de92920a717ea2b7b45bb3d651b8bb951eab185 (patch)
tree92778efc5a0c31a4a26c1ab826a56be5a12cde45
parent97b6f89f7269b746b68e7985c16d2354c688d29a (diff)
parent07a496de4c7eb0b1e80ab53f9d6465ea55ac1bd7 (diff)
Merge commit 'smp-hotplug^{/omap2}' into for-linusfor-4.21
-rw-r--r--arch/arm/mach-omap2/omap-smp.c20
-rw-r--r--arch/arm/mach-realview/Makefile1
-rw-r--r--arch/arm/mach-realview/hotplug.c111
-rw-r--r--arch/arm/mach-realview/hotplug.h1
-rw-r--r--arch/arm/mach-realview/platsmp-dt.c8
-rw-r--r--arch/arm/mach-vexpress/Makefile1
-rw-r--r--arch/arm/mach-vexpress/core.h2
-rw-r--r--arch/arm/mach-vexpress/platsmp.c7
-rw-r--r--arch/arm/plat-versatile/Makefile1
-rw-r--r--arch/arm/plat-versatile/headsmp.S2
-rw-r--r--arch/arm/plat-versatile/hotplug.c (renamed from arch/arm/mach-vexpress/hotplug.c)47
-rw-r--r--arch/arm/plat-versatile/include/plat/platsmp.h2
-rw-r--r--arch/arm/plat-versatile/platsmp.c47
13 files changed, 73 insertions, 177 deletions
diff --git a/arch/arm/mach-omap2/omap-smp.c b/arch/arm/mach-omap2/omap-smp.c
index 1c73694c871a..10e070368f64 100644
--- a/arch/arm/mach-omap2/omap-smp.c
+++ b/arch/arm/mach-omap2/omap-smp.c
@@ -69,8 +69,6 @@ static const struct omap_smp_config omap5_cfg __initconst = {
.startup_addr = omap5_secondary_startup,
};
-static DEFINE_SPINLOCK(boot_lock);
-
void __iomem *omap4_get_scu_base(void)
{
return cfg.scu_base;
@@ -173,12 +171,6 @@ static void omap4_secondary_init(unsigned int cpu)
/* Enable ACR to allow for ICUALLU workaround */
omap5_secondary_harden_predictor();
}
-
- /*
- * Synchronise with the boot thread.
- */
- spin_lock(&boot_lock);
- spin_unlock(&boot_lock);
}
static int omap4_boot_secondary(unsigned int cpu, struct task_struct *idle)
@@ -188,12 +180,6 @@ static int omap4_boot_secondary(unsigned int cpu, struct task_struct *idle)
static struct powerdomain *cpu1_pwrdm;
/*
- * Set synchronisation state between this boot processor
- * and the secondary one
- */
- spin_lock(&boot_lock);
-
- /*
* Update the AuxCoreBoot0 with boot state for secondary core.
* omap4_secondary_startup() routine will hold the secondary core till
* the AuxCoreBoot1 register is updated with cpu state
@@ -266,12 +252,6 @@ static int omap4_boot_secondary(unsigned int cpu, struct task_struct *idle)
arch_send_wakeup_ipi_mask(cpumask_of(cpu));
- /*
- * Now the secondary core is starting up let it run its
- * calibrations, then wait for it to finish
- */
- spin_unlock(&boot_lock);
-
return 0;
}
diff --git a/arch/arm/mach-realview/Makefile b/arch/arm/mach-realview/Makefile
index adf39ad71cc3..6ca6400fa51e 100644
--- a/arch/arm/mach-realview/Makefile
+++ b/arch/arm/mach-realview/Makefile
@@ -5,4 +5,3 @@ ccflags-$(CONFIG_ARCH_MULTIPLATFORM) := -I$(srctree)/arch/arm/plat-versatile/inc
obj-y += realview-dt.o
obj-$(CONFIG_SMP) += platsmp-dt.o
-obj-$(CONFIG_HOTPLUG_CPU) += hotplug.o
diff --git a/arch/arm/mach-realview/hotplug.c b/arch/arm/mach-realview/hotplug.c
deleted file mode 100644
index 968e2d1964f6..000000000000
--- a/arch/arm/mach-realview/hotplug.c
+++ /dev/null
@@ -1,111 +0,0 @@
-/*
- * linux/arch/arm/mach-realview/hotplug.c
- *
- * Copyright (C) 2002 ARM Ltd.
- * All Rights Reserved
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License version 2 as
- * published by the Free Software Foundation.
- */
-#include <linux/kernel.h>
-#include <linux/errno.h>
-#include <linux/smp.h>
-
-#include <asm/cp15.h>
-#include <asm/smp_plat.h>
-
-static inline void cpu_enter_lowpower(void)
-{
- unsigned int v;
-
- asm volatile(
- " mcr p15, 0, %1, c7, c5, 0\n"
- " mcr p15, 0, %1, c7, c10, 4\n"
- /*
- * Turn off coherency
- */
- " mrc p15, 0, %0, c1, c0, 1\n"
- " bic %0, %0, #0x20\n"
- " mcr p15, 0, %0, c1, c0, 1\n"
- " mrc p15, 0, %0, c1, c0, 0\n"
- " bic %0, %0, %2\n"
- " mcr p15, 0, %0, c1, c0, 0\n"
- : "=&r" (v)
- : "r" (0), "Ir" (CR_C)
- : "cc");
-}
-
-static inline void cpu_leave_lowpower(void)
-{
- unsigned int v;
-
- asm volatile( "mrc p15, 0, %0, c1, c0, 0\n"
- " orr %0, %0, %1\n"
- " mcr p15, 0, %0, c1, c0, 0\n"
- " mrc p15, 0, %0, c1, c0, 1\n"
- " orr %0, %0, #0x20\n"
- " mcr p15, 0, %0, c1, c0, 1\n"
- : "=&r" (v)
- : "Ir" (CR_C)
- : "cc");
-}
-
-static inline void platform_do_lowpower(unsigned int cpu, int *spurious)
-{
- /*
- * there is no power-control hardware on this platform, so all
- * we can do is put the core into WFI; this is safe as the calling
- * code will have already disabled interrupts
- */
- for (;;) {
- /*
- * here's the WFI
- */
- asm(".word 0xe320f003\n"
- :
- :
- : "memory", "cc");
-
- if (pen_release == cpu_logical_map(cpu)) {
- /*
- * OK, proper wakeup, we're done
- */
- break;
- }
-
- /*
- * Getting here, means that we have come out of WFI without
- * having been woken up - this shouldn't happen
- *
- * Just note it happening - when we're woken, we can report
- * its occurrence.
- */
- (*spurious)++;
- }
-}
-
-/*
- * platform-specific code to shutdown a CPU
- *
- * Called with IRQs disabled
- */
-void realview_cpu_die(unsigned int cpu)
-{
- int spurious = 0;
-
- /*
- * we're ready for shutdown now, so do it
- */
- cpu_enter_lowpower();
- platform_do_lowpower(cpu, &spurious);
-
- /*
- * bring this CPU back into the world of cache
- * coherency, and then restore interrupts
- */
- cpu_leave_lowpower();
-
- if (spurious)
- pr_warn("CPU%u: %u spurious wakeup calls\n", cpu, spurious);
-}
diff --git a/arch/arm/mach-realview/hotplug.h b/arch/arm/mach-realview/hotplug.h
deleted file mode 100644
index eacd7a4dad2f..000000000000
--- a/arch/arm/mach-realview/hotplug.h
+++ /dev/null
@@ -1 +0,0 @@
-void realview_cpu_die(unsigned int cpu);
diff --git a/arch/arm/mach-realview/platsmp-dt.c b/arch/arm/mach-realview/platsmp-dt.c
index c242423bf8db..ce331b3dbf54 100644
--- a/arch/arm/mach-realview/platsmp-dt.c
+++ b/arch/arm/mach-realview/platsmp-dt.c
@@ -17,7 +17,6 @@
#include <asm/smp_scu.h>
#include <plat/platsmp.h>
-#include "hotplug.h"
#define REALVIEW_SYS_FLAGSSET_OFFSET 0x30
@@ -79,6 +78,13 @@ static void __init realview_smp_prepare_cpus(unsigned int max_cpus)
__pa_symbol(versatile_secondary_startup));
}
+#ifdef CONFIG_HOTPLUG_CPU
+static void realview_cpu_die(unsigned int cpu)
+{
+ return versatile_immitation_cpu_die(cpu, 0x20);
+}
+#endif
+
static const struct smp_operations realview_dt_smp_ops __initconst = {
.smp_prepare_cpus = realview_smp_prepare_cpus,
.smp_secondary_init = versatile_secondary_init,
diff --git a/arch/arm/mach-vexpress/Makefile b/arch/arm/mach-vexpress/Makefile
index 51c35e2b737a..3651a1ed0f2b 100644
--- a/arch/arm/mach-vexpress/Makefile
+++ b/arch/arm/mach-vexpress/Makefile
@@ -15,6 +15,5 @@ obj-$(CONFIG_ARCH_VEXPRESS_TC2_PM) += tc2_pm.o
CFLAGS_tc2_pm.o += -march=armv7-a
CFLAGS_REMOVE_tc2_pm.o = -pg
obj-$(CONFIG_SMP) += platsmp.o
-obj-$(CONFIG_HOTPLUG_CPU) += hotplug.o
obj-$(CONFIG_ARCH_MPS2) += v2m-mps2.o
diff --git a/arch/arm/mach-vexpress/core.h b/arch/arm/mach-vexpress/core.h
index a162ab46ee02..f4a7519084f1 100644
--- a/arch/arm/mach-vexpress/core.h
+++ b/arch/arm/mach-vexpress/core.h
@@ -1,5 +1,3 @@
bool vexpress_smp_init_ops(void);
extern const struct smp_operations vexpress_smp_dt_ops;
-
-extern void vexpress_cpu_die(unsigned int cpu);
diff --git a/arch/arm/mach-vexpress/platsmp.c b/arch/arm/mach-vexpress/platsmp.c
index 742499bac6d0..af0113be5970 100644
--- a/arch/arm/mach-vexpress/platsmp.c
+++ b/arch/arm/mach-vexpress/platsmp.c
@@ -82,6 +82,13 @@ static void __init vexpress_smp_dt_prepare_cpus(unsigned int max_cpus)
vexpress_flags_set(__pa_symbol(versatile_secondary_startup));
}
+#ifdef CONFIG_HOTPLUG_CPU
+static void vexpress_cpu_die(unsigned int cpu)
+{
+ versatile_immitation_cpu_die(cpu, 0x40);
+}
+#endif
+
const struct smp_operations vexpress_smp_dt_ops __initconst = {
.smp_prepare_cpus = vexpress_smp_dt_prepare_cpus,
.smp_secondary_init = versatile_secondary_init,
diff --git a/arch/arm/plat-versatile/Makefile b/arch/arm/plat-versatile/Makefile
index bff3ba889882..b2f0ddfdc4cc 100644
--- a/arch/arm/plat-versatile/Makefile
+++ b/arch/arm/plat-versatile/Makefile
@@ -2,3 +2,4 @@ ccflags-$(CONFIG_ARCH_MULTIPLATFORM) := -I$(srctree)/$(src)/include
obj-$(CONFIG_PLAT_VERSATILE_SCHED_CLOCK) += sched-clock.o
obj-$(CONFIG_SMP) += headsmp.o platsmp.o
+obj-$(CONFIG_HOTPLUG_CPU) += hotplug.o
diff --git a/arch/arm/plat-versatile/headsmp.S b/arch/arm/plat-versatile/headsmp.S
index 40f27e52de75..e99396dfa6f3 100644
--- a/arch/arm/plat-versatile/headsmp.S
+++ b/arch/arm/plat-versatile/headsmp.S
@@ -37,5 +37,5 @@ pen: ldr r7, [r6]
.align
1: .long .
- .long pen_release
+ .long versatile_cpu_release
ENDPROC(versatile_secondary_startup)
diff --git a/arch/arm/mach-vexpress/hotplug.c b/arch/arm/plat-versatile/hotplug.c
index d8f1a05f5e87..c974958417fe 100644
--- a/arch/arm/mach-vexpress/hotplug.c
+++ b/arch/arm/plat-versatile/hotplug.c
@@ -1,12 +1,15 @@
/*
- * linux/arch/arm/mach-realview/hotplug.c
- *
* Copyright (C) 2002 ARM Ltd.
* All Rights Reserved
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
+ *
+ * This hotplug implementation is _specific_ to the situation found on
+ * ARM development platforms where there is _no_ possibility of actually
+ * taking a CPU offline, resetting it, or otherwise. Real platforms must
+ * NOT copy this code.
*/
#include <linux/kernel.h>
#include <linux/errno.h>
@@ -15,9 +18,9 @@
#include <asm/smp_plat.h>
#include <asm/cp15.h>
-#include "core.h"
+#include <plat/platsmp.h>
-static inline void cpu_enter_lowpower(void)
+static inline void versatile_immitation_enter_lowpower(unsigned int actrl_mask)
{
unsigned int v;
@@ -34,11 +37,11 @@ static inline void cpu_enter_lowpower(void)
" bic %0, %0, %2\n"
" mcr p15, 0, %0, c1, c0, 0\n"
: "=&r" (v)
- : "r" (0), "Ir" (CR_C), "Ir" (0x40)
+ : "r" (0), "Ir" (CR_C), "Ir" (actrl_mask)
: "cc");
}
-static inline void cpu_leave_lowpower(void)
+static inline void versatile_immitation_leave_lowpower(unsigned int actrl_mask)
{
unsigned int v;
@@ -50,21 +53,23 @@ static inline void cpu_leave_lowpower(void)
" orr %0, %0, %2\n"
" mcr p15, 0, %0, c1, c0, 1\n"
: "=&r" (v)
- : "Ir" (CR_C), "Ir" (0x40)
+ : "Ir" (CR_C), "Ir" (actrl_mask)
: "cc");
}
-static inline void platform_do_lowpower(unsigned int cpu, int *spurious)
+static inline void versatile_immitation_do_lowpower(unsigned int cpu, int *spurious)
{
/*
* there is no power-control hardware on this platform, so all
* we can do is put the core into WFI; this is safe as the calling
- * code will have already disabled interrupts
+ * code will have already disabled interrupts.
+ *
+ * This code should not be used outside Versatile platforms.
*/
for (;;) {
wfi();
- if (pen_release == cpu_logical_map(cpu)) {
+ if (versatile_cpu_release == cpu_logical_map(cpu)) {
/*
* OK, proper wakeup, we're done
*/
@@ -83,25 +88,17 @@ static inline void platform_do_lowpower(unsigned int cpu, int *spurious)
}
/*
- * platform-specific code to shutdown a CPU
- *
- * Called with IRQs disabled
+ * platform-specific code to shutdown a CPU.
+ * This code supports immitation-style CPU hotplug for Versatile/Realview/
+ * Versatile Express platforms that are unable to do real CPU hotplug.
*/
-void vexpress_cpu_die(unsigned int cpu)
+void versatile_immitation_cpu_die(unsigned int cpu, unsigned int actrl_mask)
{
int spurious = 0;
- /*
- * we're ready for shutdown now, so do it
- */
- cpu_enter_lowpower();
- platform_do_lowpower(cpu, &spurious);
-
- /*
- * bring this CPU back into the world of cache
- * coherency, and then restore interrupts
- */
- cpu_leave_lowpower();
+ versatile_immitation_enter_lowpower(actrl_mask);
+ versatile_immitation_do_lowpower(cpu, &spurious);
+ versatile_immitation_leave_lowpower(actrl_mask);
if (spurious)
pr_warn("CPU%u: %u spurious wakeup calls\n", cpu, spurious);
diff --git a/arch/arm/plat-versatile/include/plat/platsmp.h b/arch/arm/plat-versatile/include/plat/platsmp.h
index 50fb830192e0..1b087fbbc700 100644
--- a/arch/arm/plat-versatile/include/plat/platsmp.h
+++ b/arch/arm/plat-versatile/include/plat/platsmp.h
@@ -8,7 +8,9 @@
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
+extern volatile int versatile_cpu_release;
extern void versatile_secondary_startup(void);
extern void versatile_secondary_init(unsigned int cpu);
extern int versatile_boot_secondary(unsigned int cpu, struct task_struct *idle);
+void versatile_immitation_cpu_die(unsigned int cpu, unsigned int actrl_mask);
diff --git a/arch/arm/plat-versatile/platsmp.c b/arch/arm/plat-versatile/platsmp.c
index c2366510187a..6e2836243187 100644
--- a/arch/arm/plat-versatile/platsmp.c
+++ b/arch/arm/plat-versatile/platsmp.c
@@ -7,6 +7,11 @@
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
+ *
+ * This code is specific to the hardware found on ARM Realview and
+ * Versatile Express platforms where the CPUs are unable to be individually
+ * woken, and where there is no way to hot-unplug CPUs. Real platforms
+ * should not copy this code.
*/
#include <linux/init.h>
#include <linux/errno.h>
@@ -21,18 +26,32 @@
#include <plat/platsmp.h>
/*
- * Write pen_release in a way that is guaranteed to be visible to all
- * observers, irrespective of whether they're taking part in coherency
+ * versatile_cpu_release controls the release of CPUs from the holding
+ * pen in headsmp.S, which exists because we are not always able to
+ * control the release of individual CPUs from the board firmware.
+ * Production platforms do not need this.
+ */
+volatile int versatile_cpu_release = -1;
+
+/*
+ * Write versatile_cpu_release in a way that is guaranteed to be visible to
+ * all observers, irrespective of whether they're taking part in coherency
* or not. This is necessary for the hotplug code to work reliably.
*/
-static void write_pen_release(int val)
+static void versatile_write_cpu_release(int val)
{
- pen_release = val;
+ versatile_cpu_release = val;
smp_wmb();
- sync_cache_w(&pen_release);
+ sync_cache_w(&versatile_cpu_release);
}
-static DEFINE_SPINLOCK(boot_lock);
+/*
+ * versatile_lock exists to avoid running the loops_per_jiffy delay loop
+ * calibrations on the secondary CPU while the requesting CPU is using
+ * the limited-bandwidth bus - which affects the calibration value.
+ * Production platforms do not need this.
+ */
+static DEFINE_RAW_SPINLOCK(versatile_lock);
void versatile_secondary_init(unsigned int cpu)
{
@@ -40,13 +59,13 @@ void versatile_secondary_init(unsigned int cpu)
* let the primary processor know we're out of the
* pen, then head off into the C entry point
*/
- write_pen_release(-1);
+ versatile_write_cpu_release(-1);
/*
* Synchronise with the boot thread.
*/
- spin_lock(&boot_lock);
- spin_unlock(&boot_lock);
+ raw_spin_lock(&versatile_lock);
+ raw_spin_unlock(&versatile_lock);
}
int versatile_boot_secondary(unsigned int cpu, struct task_struct *idle)
@@ -57,7 +76,7 @@ int versatile_boot_secondary(unsigned int cpu, struct task_struct *idle)
* Set synchronisation state between this boot processor
* and the secondary one
*/
- spin_lock(&boot_lock);
+ raw_spin_lock(&versatile_lock);
/*
* This is really belt and braces; we hold unintended secondary
@@ -65,7 +84,7 @@ int versatile_boot_secondary(unsigned int cpu, struct task_struct *idle)
* since we haven't sent them a soft interrupt, they shouldn't
* be there.
*/
- write_pen_release(cpu_logical_map(cpu));
+ versatile_write_cpu_release(cpu_logical_map(cpu));
/*
* Send the secondary CPU a soft interrupt, thereby causing
@@ -77,7 +96,7 @@ int versatile_boot_secondary(unsigned int cpu, struct task_struct *idle)
timeout = jiffies + (1 * HZ);
while (time_before(jiffies, timeout)) {
smp_rmb();
- if (pen_release == -1)
+ if (versatile_cpu_release == -1)
break;
udelay(10);
@@ -87,7 +106,7 @@ int versatile_boot_secondary(unsigned int cpu, struct task_struct *idle)
* now the secondary core is starting up let it run its
* calibrations, then wait for it to finish
*/
- spin_unlock(&boot_lock);
+ raw_spin_unlock(&versatile_lock);
- return pen_release != -1 ? -ENOSYS : 0;
+ return versatile_cpu_release != -1 ? -ENOSYS : 0;
}