Merge branch 'devel-stable' into for-next
Conflicts: arch/arm/include/asm/atomic.h arch/arm/include/asm/hardirq.h arch/arm/kernel/smp.c
This commit is contained in:
Russell King
@@ -17,3 +17,5 @@ obj-$(CONFIG_MCPM) += mcpm_head.o mcpm_entry.o mcpm_platsmp.o vlock.o
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||||
AFLAGS_mcpm_head.o := -march=armv7-a
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AFLAGS_vlock.o := -march=armv7-a
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obj-$(CONFIG_TI_PRIV_EDMA) += edma.o
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obj-$(CONFIG_BL_SWITCHER) += bL_switcher.o
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obj-$(CONFIG_BL_SWITCHER_DUMMY_IF) += bL_switcher_dummy_if.o
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||||
822
arch/arm/common/bL_switcher.c
Normal file
822
arch/arm/common/bL_switcher.c
Normal file
@@ -0,0 +1,822 @@
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||||
/*
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* arch/arm/common/bL_switcher.c -- big.LITTLE cluster switcher core driver
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*
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* Created by: Nicolas Pitre, March 2012
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* Copyright: (C) 2012-2013 Linaro Limited
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*
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||||
* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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||||
*/
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#include <linux/atomic.h>
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#include <linux/init.h>
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||||
#include <linux/kernel.h>
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#include <linux/module.h>
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#include <linux/sched.h>
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#include <linux/interrupt.h>
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#include <linux/cpu_pm.h>
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#include <linux/cpu.h>
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#include <linux/cpumask.h>
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#include <linux/kthread.h>
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#include <linux/wait.h>
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#include <linux/time.h>
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#include <linux/clockchips.h>
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#include <linux/hrtimer.h>
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#include <linux/tick.h>
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#include <linux/notifier.h>
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#include <linux/mm.h>
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||||
#include <linux/mutex.h>
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#include <linux/smp.h>
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#include <linux/spinlock.h>
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#include <linux/string.h>
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#include <linux/sysfs.h>
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#include <linux/irqchip/arm-gic.h>
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#include <linux/moduleparam.h>
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#include <asm/smp_plat.h>
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#include <asm/cputype.h>
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#include <asm/suspend.h>
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#include <asm/mcpm.h>
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#include <asm/bL_switcher.h>
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#define CREATE_TRACE_POINTS
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#include <trace/events/power_cpu_migrate.h>
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||||
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/*
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||||
* Use our own MPIDR accessors as the generic ones in asm/cputype.h have
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* __attribute_const__ and we don't want the compiler to assume any
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* constness here as the value _does_ change along some code paths.
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||||
*/
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||||
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||||
static int read_mpidr(void)
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||||
{
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unsigned int id;
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asm volatile ("mrc p15, 0, %0, c0, c0, 5" : "=r" (id));
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return id & MPIDR_HWID_BITMASK;
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||||
}
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||||
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||||
/*
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* Get a global nanosecond time stamp for tracing.
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||||
*/
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||||
static s64 get_ns(void)
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||||
{
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struct timespec ts;
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||||
getnstimeofday(&ts);
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||||
return timespec_to_ns(&ts);
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||||
}
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||||
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||||
/*
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||||
* bL switcher core code.
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||||
*/
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||||
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static void bL_do_switch(void *_arg)
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{
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unsigned ib_mpidr, ib_cpu, ib_cluster;
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long volatile handshake, **handshake_ptr = _arg;
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pr_debug("%s\n", __func__);
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ib_mpidr = cpu_logical_map(smp_processor_id());
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||||
ib_cpu = MPIDR_AFFINITY_LEVEL(ib_mpidr, 0);
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ib_cluster = MPIDR_AFFINITY_LEVEL(ib_mpidr, 1);
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||||
/* Advertise our handshake location */
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if (handshake_ptr) {
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||||
handshake = 0;
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||||
*handshake_ptr = &handshake;
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||||
} else
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||||
handshake = -1;
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||||
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||||
/*
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* Our state has been saved at this point. Let's release our
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* inbound CPU.
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*/
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mcpm_set_entry_vector(ib_cpu, ib_cluster, cpu_resume);
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sev();
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||||
/*
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||||
* From this point, we must assume that our counterpart CPU might
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||||
* have taken over in its parallel world already, as if execution
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||||
* just returned from cpu_suspend(). It is therefore important to
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||||
* be very careful not to make any change the other guy is not
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||||
* expecting. This is why we need stack isolation.
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||||
*
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||||
* Fancy under cover tasks could be performed here. For now
|
||||
* we have none.
|
||||
*/
|
||||
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||||
/*
|
||||
* Let's wait until our inbound is alive.
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||||
*/
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||||
while (!handshake) {
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||||
wfe();
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smp_mb();
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}
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||||
|
||||
/* Let's put ourself down. */
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||||
mcpm_cpu_power_down();
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||||
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||||
/* should never get here */
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||||
BUG();
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||||
}
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||||
|
||||
/*
|
||||
* Stack isolation. To ensure 'current' remains valid, we just use another
|
||||
* piece of our thread's stack space which should be fairly lightly used.
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||||
* The selected area starts just above the thread_info structure located
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||||
* at the very bottom of the stack, aligned to a cache line, and indexed
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||||
* with the cluster number.
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||||
*/
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||||
#define STACK_SIZE 512
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||||
extern void call_with_stack(void (*fn)(void *), void *arg, void *sp);
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||||
static int bL_switchpoint(unsigned long _arg)
|
||||
{
|
||||
unsigned int mpidr = read_mpidr();
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||||
unsigned int clusterid = MPIDR_AFFINITY_LEVEL(mpidr, 1);
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||||
void *stack = current_thread_info() + 1;
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||||
stack = PTR_ALIGN(stack, L1_CACHE_BYTES);
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||||
stack += clusterid * STACK_SIZE + STACK_SIZE;
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||||
call_with_stack(bL_do_switch, (void *)_arg, stack);
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||||
BUG();
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||||
}
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|
||||
/*
|
||||
* Generic switcher interface
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||||
*/
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||||
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||||
static unsigned int bL_gic_id[MAX_CPUS_PER_CLUSTER][MAX_NR_CLUSTERS];
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||||
static int bL_switcher_cpu_pairing[NR_CPUS];
|
||||
|
||||
/*
|
||||
* bL_switch_to - Switch to a specific cluster for the current CPU
|
||||
* @new_cluster_id: the ID of the cluster to switch to.
|
||||
*
|
||||
* This function must be called on the CPU to be switched.
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||||
* Returns 0 on success, else a negative status code.
|
||||
*/
|
||||
static int bL_switch_to(unsigned int new_cluster_id)
|
||||
{
|
||||
unsigned int mpidr, this_cpu, that_cpu;
|
||||
unsigned int ob_mpidr, ob_cpu, ob_cluster, ib_mpidr, ib_cpu, ib_cluster;
|
||||
struct completion inbound_alive;
|
||||
struct tick_device *tdev;
|
||||
enum clock_event_mode tdev_mode;
|
||||
long volatile *handshake_ptr;
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||||
int ipi_nr, ret;
|
||||
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||||
this_cpu = smp_processor_id();
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||||
ob_mpidr = read_mpidr();
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||||
ob_cpu = MPIDR_AFFINITY_LEVEL(ob_mpidr, 0);
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||||
ob_cluster = MPIDR_AFFINITY_LEVEL(ob_mpidr, 1);
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BUG_ON(cpu_logical_map(this_cpu) != ob_mpidr);
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||||
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if (new_cluster_id == ob_cluster)
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||||
return 0;
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||||
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||||
that_cpu = bL_switcher_cpu_pairing[this_cpu];
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||||
ib_mpidr = cpu_logical_map(that_cpu);
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ib_cpu = MPIDR_AFFINITY_LEVEL(ib_mpidr, 0);
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||||
ib_cluster = MPIDR_AFFINITY_LEVEL(ib_mpidr, 1);
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||||
pr_debug("before switch: CPU %d MPIDR %#x -> %#x\n",
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this_cpu, ob_mpidr, ib_mpidr);
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||||
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||||
this_cpu = smp_processor_id();
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||||
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||||
/* Close the gate for our entry vectors */
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||||
mcpm_set_entry_vector(ob_cpu, ob_cluster, NULL);
|
||||
mcpm_set_entry_vector(ib_cpu, ib_cluster, NULL);
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||||
|
||||
/* Install our "inbound alive" notifier. */
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||||
init_completion(&inbound_alive);
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||||
ipi_nr = register_ipi_completion(&inbound_alive, this_cpu);
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ipi_nr |= ((1 << 16) << bL_gic_id[ob_cpu][ob_cluster]);
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mcpm_set_early_poke(ib_cpu, ib_cluster, gic_get_sgir_physaddr(), ipi_nr);
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||||
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||||
/*
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||||
* Let's wake up the inbound CPU now in case it requires some delay
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||||
* to come online, but leave it gated in our entry vector code.
|
||||
*/
|
||||
ret = mcpm_cpu_power_up(ib_cpu, ib_cluster);
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||||
if (ret) {
|
||||
pr_err("%s: mcpm_cpu_power_up() returned %d\n", __func__, ret);
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||||
return ret;
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||||
}
|
||||
|
||||
/*
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||||
* Raise a SGI on the inbound CPU to make sure it doesn't stall
|
||||
* in a possible WFI, such as in bL_power_down().
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||||
*/
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||||
gic_send_sgi(bL_gic_id[ib_cpu][ib_cluster], 0);
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||||
|
||||
/*
|
||||
* Wait for the inbound to come up. This allows for other
|
||||
* tasks to be scheduled in the mean time.
|
||||
*/
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||||
wait_for_completion(&inbound_alive);
|
||||
mcpm_set_early_poke(ib_cpu, ib_cluster, 0, 0);
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||||
|
||||
/*
|
||||
* From this point we are entering the switch critical zone
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||||
* and can't take any interrupts anymore.
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||||
*/
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||||
local_irq_disable();
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local_fiq_disable();
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||||
trace_cpu_migrate_begin(get_ns(), ob_mpidr);
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||||
|
||||
/* redirect GIC's SGIs to our counterpart */
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||||
gic_migrate_target(bL_gic_id[ib_cpu][ib_cluster]);
|
||||
|
||||
tdev = tick_get_device(this_cpu);
|
||||
if (tdev && !cpumask_equal(tdev->evtdev->cpumask, cpumask_of(this_cpu)))
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||||
tdev = NULL;
|
||||
if (tdev) {
|
||||
tdev_mode = tdev->evtdev->mode;
|
||||
clockevents_set_mode(tdev->evtdev, CLOCK_EVT_MODE_SHUTDOWN);
|
||||
}
|
||||
|
||||
ret = cpu_pm_enter();
|
||||
|
||||
/* we can not tolerate errors at this point */
|
||||
if (ret)
|
||||
panic("%s: cpu_pm_enter() returned %d\n", __func__, ret);
|
||||
|
||||
/* Swap the physical CPUs in the logical map for this logical CPU. */
|
||||
cpu_logical_map(this_cpu) = ib_mpidr;
|
||||
cpu_logical_map(that_cpu) = ob_mpidr;
|
||||
|
||||
/* Let's do the actual CPU switch. */
|
||||
ret = cpu_suspend((unsigned long)&handshake_ptr, bL_switchpoint);
|
||||
if (ret > 0)
|
||||
panic("%s: cpu_suspend() returned %d\n", __func__, ret);
|
||||
|
||||
/* We are executing on the inbound CPU at this point */
|
||||
mpidr = read_mpidr();
|
||||
pr_debug("after switch: CPU %d MPIDR %#x\n", this_cpu, mpidr);
|
||||
BUG_ON(mpidr != ib_mpidr);
|
||||
|
||||
mcpm_cpu_powered_up();
|
||||
|
||||
ret = cpu_pm_exit();
|
||||
|
||||
if (tdev) {
|
||||
clockevents_set_mode(tdev->evtdev, tdev_mode);
|
||||
clockevents_program_event(tdev->evtdev,
|
||||
tdev->evtdev->next_event, 1);
|
||||
}
|
||||
|
||||
trace_cpu_migrate_finish(get_ns(), ib_mpidr);
|
||||
local_fiq_enable();
|
||||
local_irq_enable();
|
||||
|
||||
*handshake_ptr = 1;
|
||||
dsb_sev();
|
||||
|
||||
if (ret)
|
||||
pr_err("%s exiting with error %d\n", __func__, ret);
|
||||
return ret;
|
||||
}
|
||||
|
||||
struct bL_thread {
|
||||
spinlock_t lock;
|
||||
struct task_struct *task;
|
||||
wait_queue_head_t wq;
|
||||
int wanted_cluster;
|
||||
struct completion started;
|
||||
bL_switch_completion_handler completer;
|
||||
void *completer_cookie;
|
||||
};
|
||||
|
||||
static struct bL_thread bL_threads[NR_CPUS];
|
||||
|
||||
static int bL_switcher_thread(void *arg)
|
||||
{
|
||||
struct bL_thread *t = arg;
|
||||
struct sched_param param = { .sched_priority = 1 };
|
||||
int cluster;
|
||||
bL_switch_completion_handler completer;
|
||||
void *completer_cookie;
|
||||
|
||||
sched_setscheduler_nocheck(current, SCHED_FIFO, ¶m);
|
||||
complete(&t->started);
|
||||
|
||||
do {
|
||||
if (signal_pending(current))
|
||||
flush_signals(current);
|
||||
wait_event_interruptible(t->wq,
|
||||
t->wanted_cluster != -1 ||
|
||||
kthread_should_stop());
|
||||
|
||||
spin_lock(&t->lock);
|
||||
cluster = t->wanted_cluster;
|
||||
completer = t->completer;
|
||||
completer_cookie = t->completer_cookie;
|
||||
t->wanted_cluster = -1;
|
||||
t->completer = NULL;
|
||||
spin_unlock(&t->lock);
|
||||
|
||||
if (cluster != -1) {
|
||||
bL_switch_to(cluster);
|
||||
|
||||
if (completer)
|
||||
completer(completer_cookie);
|
||||
}
|
||||
} while (!kthread_should_stop());
|
||||
|
||||
return 0;
|
||||
}
|
||||
|
||||
static struct task_struct *bL_switcher_thread_create(int cpu, void *arg)
|
||||
{
|
||||
struct task_struct *task;
|
||||
|
||||
task = kthread_create_on_node(bL_switcher_thread, arg,
|
||||
cpu_to_node(cpu), "kswitcher_%d", cpu);
|
||||
if (!IS_ERR(task)) {
|
||||
kthread_bind(task, cpu);
|
||||
wake_up_process(task);
|
||||
} else
|
||||
pr_err("%s failed for CPU %d\n", __func__, cpu);
|
||||
return task;
|
||||
}
|
||||
|
||||
/*
|
||||
* bL_switch_request_cb - Switch to a specific cluster for the given CPU,
|
||||
* with completion notification via a callback
|
||||
*
|
||||
* @cpu: the CPU to switch
|
||||
* @new_cluster_id: the ID of the cluster to switch to.
|
||||
* @completer: switch completion callback. if non-NULL,
|
||||
* @completer(@completer_cookie) will be called on completion of
|
||||
* the switch, in non-atomic context.
|
||||
* @completer_cookie: opaque context argument for @completer.
|
||||
*
|
||||
* This function causes a cluster switch on the given CPU by waking up
|
||||
* the appropriate switcher thread. This function may or may not return
|
||||
* before the switch has occurred.
|
||||
*
|
||||
* If a @completer callback function is supplied, it will be called when
|
||||
* the switch is complete. This can be used to determine asynchronously
|
||||
* when the switch is complete, regardless of when bL_switch_request()
|
||||
* returns. When @completer is supplied, no new switch request is permitted
|
||||
* for the affected CPU until after the switch is complete, and @completer
|
||||
* has returned.
|
||||
*/
|
||||
int bL_switch_request_cb(unsigned int cpu, unsigned int new_cluster_id,
|
||||
bL_switch_completion_handler completer,
|
||||
void *completer_cookie)
|
||||
{
|
||||
struct bL_thread *t;
|
||||
|
||||
if (cpu >= ARRAY_SIZE(bL_threads)) {
|
||||
pr_err("%s: cpu %d out of bounds\n", __func__, cpu);
|
||||
return -EINVAL;
|
||||
}
|
||||
|
||||
t = &bL_threads[cpu];
|
||||
|
||||
if (IS_ERR(t->task))
|
||||
return PTR_ERR(t->task);
|
||||
if (!t->task)
|
||||
return -ESRCH;
|
||||
|
||||
spin_lock(&t->lock);
|
||||
if (t->completer) {
|
||||
spin_unlock(&t->lock);
|
||||
return -EBUSY;
|
||||
}
|
||||
t->completer = completer;
|
||||
t->completer_cookie = completer_cookie;
|
||||
t->wanted_cluster = new_cluster_id;
|
||||
spin_unlock(&t->lock);
|
||||
wake_up(&t->wq);
|
||||
return 0;
|
||||
}
|
||||
EXPORT_SYMBOL_GPL(bL_switch_request_cb);
|
||||
|
||||
/*
|
||||
* Activation and configuration code.
|
||||
*/
|
||||
|
||||
static DEFINE_MUTEX(bL_switcher_activation_lock);
|
||||
static BLOCKING_NOTIFIER_HEAD(bL_activation_notifier);
|
||||
static unsigned int bL_switcher_active;
|
||||
static unsigned int bL_switcher_cpu_original_cluster[NR_CPUS];
|
||||
static cpumask_t bL_switcher_removed_logical_cpus;
|
||||
|
||||
int bL_switcher_register_notifier(struct notifier_block *nb)
|
||||
{
|
||||
return blocking_notifier_chain_register(&bL_activation_notifier, nb);
|
||||
}
|
||||
EXPORT_SYMBOL_GPL(bL_switcher_register_notifier);
|
||||
|
||||
int bL_switcher_unregister_notifier(struct notifier_block *nb)
|
||||
{
|
||||
return blocking_notifier_chain_unregister(&bL_activation_notifier, nb);
|
||||
}
|
||||
EXPORT_SYMBOL_GPL(bL_switcher_unregister_notifier);
|
||||
|
||||
static int bL_activation_notify(unsigned long val)
|
||||
{
|
||||
int ret;
|
||||
|
||||
ret = blocking_notifier_call_chain(&bL_activation_notifier, val, NULL);
|
||||
if (ret & NOTIFY_STOP_MASK)
|
||||
pr_err("%s: notifier chain failed with status 0x%x\n",
|
||||
__func__, ret);
|
||||
return notifier_to_errno(ret);
|
||||
}
|
||||
|
||||
static void bL_switcher_restore_cpus(void)
|
||||
{
|
||||
int i;
|
||||
|
||||
for_each_cpu(i, &bL_switcher_removed_logical_cpus)
|
||||
cpu_up(i);
|
||||
}
|
||||
|
||||
static int bL_switcher_halve_cpus(void)
|
||||
{
|
||||
int i, j, cluster_0, gic_id, ret;
|
||||
unsigned int cpu, cluster, mask;
|
||||
cpumask_t available_cpus;
|
||||
|
||||
/* First pass to validate what we have */
|
||||
mask = 0;
|
||||
for_each_online_cpu(i) {
|
||||
cpu = MPIDR_AFFINITY_LEVEL(cpu_logical_map(i), 0);
|
||||
cluster = MPIDR_AFFINITY_LEVEL(cpu_logical_map(i), 1);
|
||||
if (cluster >= 2) {
|
||||
pr_err("%s: only dual cluster systems are supported\n", __func__);
|
||||
return -EINVAL;
|
||||
}
|
||||
if (WARN_ON(cpu >= MAX_CPUS_PER_CLUSTER))
|
||||
return -EINVAL;
|
||||
mask |= (1 << cluster);
|
||||
}
|
||||
if (mask != 3) {
|
||||
pr_err("%s: no CPU pairing possible\n", __func__);
|
||||
return -EINVAL;
|
||||
}
|
||||
|
||||
/*
|
||||
* Now let's do the pairing. We match each CPU with another CPU
|
||||
* from a different cluster. To get a uniform scheduling behavior
|
||||
* without fiddling with CPU topology and compute capacity data,
|
||||
* we'll use logical CPUs initially belonging to the same cluster.
|
||||
*/
|
||||
memset(bL_switcher_cpu_pairing, -1, sizeof(bL_switcher_cpu_pairing));
|
||||
cpumask_copy(&available_cpus, cpu_online_mask);
|
||||
cluster_0 = -1;
|
||||
for_each_cpu(i, &available_cpus) {
|
||||
int match = -1;
|
||||
cluster = MPIDR_AFFINITY_LEVEL(cpu_logical_map(i), 1);
|
||||
if (cluster_0 == -1)
|
||||
cluster_0 = cluster;
|
||||
if (cluster != cluster_0)
|
||||
continue;
|
||||
cpumask_clear_cpu(i, &available_cpus);
|
||||
for_each_cpu(j, &available_cpus) {
|
||||
cluster = MPIDR_AFFINITY_LEVEL(cpu_logical_map(j), 1);
|
||||
/*
|
||||
* Let's remember the last match to create "odd"
|
||||
* pairings on purpose in order for other code not
|
||||
* to assume any relation between physical and
|
||||
* logical CPU numbers.
|
||||
*/
|
||||
if (cluster != cluster_0)
|
||||
match = j;
|
||||
}
|
||||
if (match != -1) {
|
||||
bL_switcher_cpu_pairing[i] = match;
|
||||
cpumask_clear_cpu(match, &available_cpus);
|
||||
pr_info("CPU%d paired with CPU%d\n", i, match);
|
||||
}
|
||||
}
|
||||
|
||||
/*
|
||||
* Now we disable the unwanted CPUs i.e. everything that has no
|
||||
* pairing information (that includes the pairing counterparts).
|
||||
*/
|
||||
cpumask_clear(&bL_switcher_removed_logical_cpus);
|
||||
for_each_online_cpu(i) {
|
||||
cpu = MPIDR_AFFINITY_LEVEL(cpu_logical_map(i), 0);
|
||||
cluster = MPIDR_AFFINITY_LEVEL(cpu_logical_map(i), 1);
|
||||
|
||||
/* Let's take note of the GIC ID for this CPU */
|
||||
gic_id = gic_get_cpu_id(i);
|
||||
if (gic_id < 0) {
|
||||
pr_err("%s: bad GIC ID for CPU %d\n", __func__, i);
|
||||
bL_switcher_restore_cpus();
|
||||
return -EINVAL;
|
||||
}
|
||||
bL_gic_id[cpu][cluster] = gic_id;
|
||||
pr_info("GIC ID for CPU %u cluster %u is %u\n",
|
||||
cpu, cluster, gic_id);
|
||||
|
||||
if (bL_switcher_cpu_pairing[i] != -1) {
|
||||
bL_switcher_cpu_original_cluster[i] = cluster;
|
||||
continue;
|
||||
}
|
||||
|
||||
ret = cpu_down(i);
|
||||
if (ret) {
|
||||
bL_switcher_restore_cpus();
|
||||
return ret;
|
||||
}
|
||||
cpumask_set_cpu(i, &bL_switcher_removed_logical_cpus);
|
||||
}
|
||||
|
||||
return 0;
|
||||
}
|
||||
|
||||
/* Determine the logical CPU a given physical CPU is grouped on. */
|
||||
int bL_switcher_get_logical_index(u32 mpidr)
|
||||
{
|
||||
int cpu;
|
||||
|
||||
if (!bL_switcher_active)
|
||||
return -EUNATCH;
|
||||
|
||||
mpidr &= MPIDR_HWID_BITMASK;
|
||||
for_each_online_cpu(cpu) {
|
||||
int pairing = bL_switcher_cpu_pairing[cpu];
|
||||
if (pairing == -1)
|
||||
continue;
|
||||
if ((mpidr == cpu_logical_map(cpu)) ||
|
||||
(mpidr == cpu_logical_map(pairing)))
|
||||
return cpu;
|
||||
}
|
||||
return -EINVAL;
|
||||
}
|
||||
|
||||
static void bL_switcher_trace_trigger_cpu(void *__always_unused info)
|
||||
{
|
||||
trace_cpu_migrate_current(get_ns(), read_mpidr());
|
||||
}
|
||||
|
||||
int bL_switcher_trace_trigger(void)
|
||||
{
|
||||
int ret;
|
||||
|
||||
preempt_disable();
|
||||
|
||||
bL_switcher_trace_trigger_cpu(NULL);
|
||||
ret = smp_call_function(bL_switcher_trace_trigger_cpu, NULL, true);
|
||||
|
||||
preempt_enable();
|
||||
|
||||
return ret;
|
||||
}
|
||||
EXPORT_SYMBOL_GPL(bL_switcher_trace_trigger);
|
||||
|
||||
static int bL_switcher_enable(void)
|
||||
{
|
||||
int cpu, ret;
|
||||
|
||||
mutex_lock(&bL_switcher_activation_lock);
|
||||
lock_device_hotplug();
|
||||
if (bL_switcher_active) {
|
||||
unlock_device_hotplug();
|
||||
mutex_unlock(&bL_switcher_activation_lock);
|
||||
return 0;
|
||||
}
|
||||
|
||||
pr_info("big.LITTLE switcher initializing\n");
|
||||
|
||||
ret = bL_activation_notify(BL_NOTIFY_PRE_ENABLE);
|
||||
if (ret)
|
||||
goto error;
|
||||
|
||||
ret = bL_switcher_halve_cpus();
|
||||
if (ret)
|
||||
goto error;
|
||||
|
||||
bL_switcher_trace_trigger();
|
||||
|
||||
for_each_online_cpu(cpu) {
|
||||
struct bL_thread *t = &bL_threads[cpu];
|
||||
spin_lock_init(&t->lock);
|
||||
init_waitqueue_head(&t->wq);
|
||||
init_completion(&t->started);
|
||||
t->wanted_cluster = -1;
|
||||
t->task = bL_switcher_thread_create(cpu, t);
|
||||
}
|
||||
|
||||
bL_switcher_active = 1;
|
||||
bL_activation_notify(BL_NOTIFY_POST_ENABLE);
|
||||
pr_info("big.LITTLE switcher initialized\n");
|
||||
goto out;
|
||||
|
||||
error:
|
||||
pr_warn("big.LITTLE switcher initialization failed\n");
|
||||
bL_activation_notify(BL_NOTIFY_POST_DISABLE);
|
||||
|
||||
out:
|
||||
unlock_device_hotplug();
|
||||
mutex_unlock(&bL_switcher_activation_lock);
|
||||
return ret;
|
||||
}
|
||||
|
||||
#ifdef CONFIG_SYSFS
|
||||
|
||||
static void bL_switcher_disable(void)
|
||||
{
|
||||
unsigned int cpu, cluster;
|
||||
struct bL_thread *t;
|
||||
struct task_struct *task;
|
||||
|
||||
mutex_lock(&bL_switcher_activation_lock);
|
||||
lock_device_hotplug();
|
||||
|
||||
if (!bL_switcher_active)
|
||||
goto out;
|
||||
|
||||
if (bL_activation_notify(BL_NOTIFY_PRE_DISABLE) != 0) {
|
||||
bL_activation_notify(BL_NOTIFY_POST_ENABLE);
|
||||
goto out;
|
||||
}
|
||||
|
||||
bL_switcher_active = 0;
|
||||
|
||||
/*
|
||||
* To deactivate the switcher, we must shut down the switcher
|
||||
* threads to prevent any other requests from being accepted.
|
||||
* Then, if the final cluster for given logical CPU is not the
|
||||
* same as the original one, we'll recreate a switcher thread
|
||||
* just for the purpose of switching the CPU back without any
|
||||
* possibility for interference from external requests.
|
||||
*/
|
||||
for_each_online_cpu(cpu) {
|
||||
t = &bL_threads[cpu];
|
||||
task = t->task;
|
||||
t->task = NULL;
|
||||
if (!task || IS_ERR(task))
|
||||
continue;
|
||||
kthread_stop(task);
|
||||
/* no more switch may happen on this CPU at this point */
|
||||
cluster = MPIDR_AFFINITY_LEVEL(cpu_logical_map(cpu), 1);
|
||||
if (cluster == bL_switcher_cpu_original_cluster[cpu])
|
||||
continue;
|
||||
init_completion(&t->started);
|
||||
t->wanted_cluster = bL_switcher_cpu_original_cluster[cpu];
|
||||
task = bL_switcher_thread_create(cpu, t);
|
||||
if (!IS_ERR(task)) {
|
||||
wait_for_completion(&t->started);
|
||||
kthread_stop(task);
|
||||
cluster = MPIDR_AFFINITY_LEVEL(cpu_logical_map(cpu), 1);
|
||||
if (cluster == bL_switcher_cpu_original_cluster[cpu])
|
||||
continue;
|
||||
}
|
||||
/* If execution gets here, we're in trouble. */
|
||||
pr_crit("%s: unable to restore original cluster for CPU %d\n",
|
||||
__func__, cpu);
|
||||
pr_crit("%s: CPU %d can't be restored\n",
|
||||
__func__, bL_switcher_cpu_pairing[cpu]);
|
||||
cpumask_clear_cpu(bL_switcher_cpu_pairing[cpu],
|
||||
&bL_switcher_removed_logical_cpus);
|
||||
}
|
||||
|
||||
bL_switcher_restore_cpus();
|
||||
bL_switcher_trace_trigger();
|
||||
|
||||
bL_activation_notify(BL_NOTIFY_POST_DISABLE);
|
||||
|
||||
out:
|
||||
unlock_device_hotplug();
|
||||
mutex_unlock(&bL_switcher_activation_lock);
|
||||
}
|
||||
|
||||
static ssize_t bL_switcher_active_show(struct kobject *kobj,
|
||||
struct kobj_attribute *attr, char *buf)
|
||||
{
|
||||
return sprintf(buf, "%u\n", bL_switcher_active);
|
||||
}
|
||||
|
||||
static ssize_t bL_switcher_active_store(struct kobject *kobj,
|
||||
struct kobj_attribute *attr, const char *buf, size_t count)
|
||||
{
|
||||
int ret;
|
||||
|
||||
switch (buf[0]) {
|
||||
case '0':
|
||||
bL_switcher_disable();
|
||||
ret = 0;
|
||||
break;
|
||||
case '1':
|
||||
ret = bL_switcher_enable();
|
||||
break;
|
||||
default:
|
||||
ret = -EINVAL;
|
||||
}
|
||||
|
||||
return (ret >= 0) ? count : ret;
|
||||
}
|
||||
|
||||
static ssize_t bL_switcher_trace_trigger_store(struct kobject *kobj,
|
||||
struct kobj_attribute *attr, const char *buf, size_t count)
|
||||
{
|
||||
int ret = bL_switcher_trace_trigger();
|
||||
|
||||
return ret ? ret : count;
|
||||
}
|
||||
|
||||
static struct kobj_attribute bL_switcher_active_attr =
|
||||
__ATTR(active, 0644, bL_switcher_active_show, bL_switcher_active_store);
|
||||
|
||||
static struct kobj_attribute bL_switcher_trace_trigger_attr =
|
||||
__ATTR(trace_trigger, 0200, NULL, bL_switcher_trace_trigger_store);
|
||||
|
||||
static struct attribute *bL_switcher_attrs[] = {
|
||||
&bL_switcher_active_attr.attr,
|
||||
&bL_switcher_trace_trigger_attr.attr,
|
||||
NULL,
|
||||
};
|
||||
|
||||
static struct attribute_group bL_switcher_attr_group = {
|
||||
.attrs = bL_switcher_attrs,
|
||||
};
|
||||
|
||||
static struct kobject *bL_switcher_kobj;
|
||||
|
||||
static int __init bL_switcher_sysfs_init(void)
|
||||
{
|
||||
int ret;
|
||||
|
||||
bL_switcher_kobj = kobject_create_and_add("bL_switcher", kernel_kobj);
|
||||
if (!bL_switcher_kobj)
|
||||
return -ENOMEM;
|
||||
ret = sysfs_create_group(bL_switcher_kobj, &bL_switcher_attr_group);
|
||||
if (ret)
|
||||
kobject_put(bL_switcher_kobj);
|
||||
return ret;
|
||||
}
|
||||
|
||||
#endif /* CONFIG_SYSFS */
|
||||
|
||||
bool bL_switcher_get_enabled(void)
|
||||
{
|
||||
mutex_lock(&bL_switcher_activation_lock);
|
||||
|
||||
return bL_switcher_active;
|
||||
}
|
||||
EXPORT_SYMBOL_GPL(bL_switcher_get_enabled);
|
||||
|
||||
void bL_switcher_put_enabled(void)
|
||||
{
|
||||
mutex_unlock(&bL_switcher_activation_lock);
|
||||
}
|
||||
EXPORT_SYMBOL_GPL(bL_switcher_put_enabled);
|
||||
|
||||
/*
|
||||
* Veto any CPU hotplug operation on those CPUs we've removed
|
||||
* while the switcher is active.
|
||||
* We're just not ready to deal with that given the trickery involved.
|
||||
*/
|
||||
static int bL_switcher_hotplug_callback(struct notifier_block *nfb,
|
||||
unsigned long action, void *hcpu)
|
||||
{
|
||||
if (bL_switcher_active) {
|
||||
int pairing = bL_switcher_cpu_pairing[(unsigned long)hcpu];
|
||||
switch (action & 0xf) {
|
||||
case CPU_UP_PREPARE:
|
||||
case CPU_DOWN_PREPARE:
|
||||
if (pairing == -1)
|
||||
return NOTIFY_BAD;
|
||||
}
|
||||
}
|
||||
return NOTIFY_DONE;
|
||||
}
|
||||
|
||||
static bool no_bL_switcher;
|
||||
core_param(no_bL_switcher, no_bL_switcher, bool, 0644);
|
||||
|
||||
static int __init bL_switcher_init(void)
|
||||
{
|
||||
int ret;
|
||||
|
||||
if (MAX_NR_CLUSTERS != 2) {
|
||||
pr_err("%s: only dual cluster systems are supported\n", __func__);
|
||||
return -EINVAL;
|
||||
}
|
||||
|
||||
cpu_notifier(bL_switcher_hotplug_callback, 0);
|
||||
|
||||
if (!no_bL_switcher) {
|
||||
ret = bL_switcher_enable();
|
||||
if (ret)
|
||||
return ret;
|
||||
}
|
||||
|
||||
#ifdef CONFIG_SYSFS
|
||||
ret = bL_switcher_sysfs_init();
|
||||
if (ret)
|
||||
pr_err("%s: unable to create sysfs entry\n", __func__);
|
||||
#endif
|
||||
|
||||
return 0;
|
||||
}
|
||||
|
||||
late_initcall(bL_switcher_init);
|
||||
71
arch/arm/common/bL_switcher_dummy_if.c
Normal file
71
arch/arm/common/bL_switcher_dummy_if.c
Normal file
@@ -0,0 +1,71 @@
|
||||
/*
|
||||
* arch/arm/common/bL_switcher_dummy_if.c -- b.L switcher dummy interface
|
||||
*
|
||||
* Created by: Nicolas Pitre, November 2012
|
||||
* Copyright: (C) 2012-2013 Linaro Limited
|
||||
*
|
||||
* Dummy interface to user space for debugging purpose only.
|
||||
*
|
||||
* 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/init.h>
|
||||
#include <linux/module.h>
|
||||
#include <linux/fs.h>
|
||||
#include <linux/miscdevice.h>
|
||||
#include <asm/uaccess.h>
|
||||
#include <asm/bL_switcher.h>
|
||||
|
||||
static ssize_t bL_switcher_write(struct file *file, const char __user *buf,
|
||||
size_t len, loff_t *pos)
|
||||
{
|
||||
unsigned char val[3];
|
||||
unsigned int cpu, cluster;
|
||||
int ret;
|
||||
|
||||
pr_debug("%s\n", __func__);
|
||||
|
||||
if (len < 3)
|
||||
return -EINVAL;
|
||||
|
||||
if (copy_from_user(val, buf, 3))
|
||||
return -EFAULT;
|
||||
|
||||
/* format: <cpu#>,<cluster#> */
|
||||
if (val[0] < '0' || val[0] > '9' ||
|
||||
val[1] != ',' ||
|
||||
val[2] < '0' || val[2] > '1')
|
||||
return -EINVAL;
|
||||
|
||||
cpu = val[0] - '0';
|
||||
cluster = val[2] - '0';
|
||||
ret = bL_switch_request(cpu, cluster);
|
||||
|
||||
return ret ? : len;
|
||||
}
|
||||
|
||||
static const struct file_operations bL_switcher_fops = {
|
||||
.write = bL_switcher_write,
|
||||
.owner = THIS_MODULE,
|
||||
};
|
||||
|
||||
static struct miscdevice bL_switcher_device = {
|
||||
MISC_DYNAMIC_MINOR,
|
||||
"b.L_switcher",
|
||||
&bL_switcher_fops
|
||||
};
|
||||
|
||||
static int __init bL_switcher_dummy_if_init(void)
|
||||
{
|
||||
return misc_register(&bL_switcher_device);
|
||||
}
|
||||
|
||||
static void __exit bL_switcher_dummy_if_exit(void)
|
||||
{
|
||||
misc_deregister(&bL_switcher_device);
|
||||
}
|
||||
|
||||
module_init(bL_switcher_dummy_if_init);
|
||||
module_exit(bL_switcher_dummy_if_exit);
|
||||
@@ -27,6 +27,18 @@ void mcpm_set_entry_vector(unsigned cpu, unsigned cluster, void *ptr)
|
||||
sync_cache_w(&mcpm_entry_vectors[cluster][cpu]);
|
||||
}
|
||||
|
||||
extern unsigned long mcpm_entry_early_pokes[MAX_NR_CLUSTERS][MAX_CPUS_PER_CLUSTER][2];
|
||||
|
||||
void mcpm_set_early_poke(unsigned cpu, unsigned cluster,
|
||||
unsigned long poke_phys_addr, unsigned long poke_val)
|
||||
{
|
||||
unsigned long *poke = &mcpm_entry_early_pokes[cluster][cpu][0];
|
||||
poke[0] = poke_phys_addr;
|
||||
poke[1] = poke_val;
|
||||
__cpuc_flush_dcache_area((void *)poke, 8);
|
||||
outer_clean_range(__pa(poke), __pa(poke + 2));
|
||||
}
|
||||
|
||||
static const struct mcpm_platform_ops *platform_ops;
|
||||
|
||||
int __init mcpm_platform_register(const struct mcpm_platform_ops *ops)
|
||||
|
||||
@@ -15,6 +15,7 @@
|
||||
|
||||
#include <linux/linkage.h>
|
||||
#include <asm/mcpm.h>
|
||||
#include <asm/assembler.h>
|
||||
|
||||
#include "vlock.h"
|
||||
|
||||
@@ -47,6 +48,7 @@
|
||||
|
||||
ENTRY(mcpm_entry_point)
|
||||
|
||||
ARM_BE8(setend be)
|
||||
THUMB( adr r12, BSYM(1f) )
|
||||
THUMB( bx r12 )
|
||||
THUMB( .thumb )
|
||||
@@ -71,12 +73,19 @@ ENTRY(mcpm_entry_point)
|
||||
* position independent way.
|
||||
*/
|
||||
adr r5, 3f
|
||||
ldmia r5, {r6, r7, r8, r11}
|
||||
ldmia r5, {r0, r6, r7, r8, r11}
|
||||
add r0, r5, r0 @ r0 = mcpm_entry_early_pokes
|
||||
add r6, r5, r6 @ r6 = mcpm_entry_vectors
|
||||
ldr r7, [r5, r7] @ r7 = mcpm_power_up_setup_phys
|
||||
add r8, r5, r8 @ r8 = mcpm_sync
|
||||
add r11, r5, r11 @ r11 = first_man_locks
|
||||
|
||||
@ Perform an early poke, if any
|
||||
add r0, r0, r4, lsl #3
|
||||
ldmia r0, {r0, r1}
|
||||
teq r0, #0
|
||||
strne r1, [r0]
|
||||
|
||||
mov r0, #MCPM_SYNC_CLUSTER_SIZE
|
||||
mla r8, r0, r10, r8 @ r8 = sync cluster base
|
||||
|
||||
@@ -195,7 +204,8 @@ mcpm_entry_gated:
|
||||
|
||||
.align 2
|
||||
|
||||
3: .word mcpm_entry_vectors - .
|
||||
3: .word mcpm_entry_early_pokes - .
|
||||
.word mcpm_entry_vectors - 3b
|
||||
.word mcpm_power_up_setup_phys - 3b
|
||||
.word mcpm_sync - 3b
|
||||
.word first_man_locks - 3b
|
||||
@@ -214,6 +224,10 @@ first_man_locks:
|
||||
ENTRY(mcpm_entry_vectors)
|
||||
.space 4 * MAX_NR_CLUSTERS * MAX_CPUS_PER_CLUSTER
|
||||
|
||||
.type mcpm_entry_early_pokes, #object
|
||||
ENTRY(mcpm_entry_early_pokes)
|
||||
.space 8 * MAX_NR_CLUSTERS * MAX_CPUS_PER_CLUSTER
|
||||
|
||||
.type mcpm_power_up_setup_phys, #object
|
||||
ENTRY(mcpm_power_up_setup_phys)
|
||||
.space 4 @ set by mcpm_sync_init()
|
||||
|
||||
Reference in New Issue
Block a user