Hexagon: Add SMP support

Signed-off-by: Richard Kuo <rkuo@codeaurora.org>
Signed-off-by: Linas Vepstas <linas@codeaurora.org>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Richard Kuo 2011-10-31 18:46:34 -05:00 committed by Linus Torvalds
parent cf9750bae2
commit 43afdf5083
3 changed files with 372 additions and 0 deletions

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/*
* SMP definitions for the Hexagon architecture
*
* Copyright (c) 2010-2011, Code Aurora Forum. 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 and
* only version 2 as published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
* 02110-1301, USA.
*/
#ifndef __ASM_SMP_H
#define __ASM_SMP_H
#include <linux/cpumask.h>
#define raw_smp_processor_id() (current_thread_info()->cpu)
enum ipi_message_type {
IPI_NOP = 0,
IPI_RESCHEDULE = 1,
IPI_CALL_FUNC,
IPI_CALL_FUNC_SINGLE,
IPI_CPU_STOP,
IPI_TIMER,
};
extern void send_ipi(const struct cpumask *cpumask, enum ipi_message_type msg);
extern void smp_start_cpus(void);
extern void arch_send_call_function_single_ipi(int cpu);
extern void arch_send_call_function_ipi_mask(const struct cpumask *mask);
extern void smp_vm_unmask_irq(void *info);
#endif

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arch/hexagon/kernel/smp.c Normal file
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/*
* SMP support for Hexagon
*
* Copyright (c) 2010-2011, Code Aurora Forum. 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 and
* only version 2 as published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
* 02110-1301, USA.
*/
#include <linux/err.h>
#include <linux/errno.h>
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/module.h>
#include <linux/percpu.h>
#include <linux/sched.h>
#include <linux/smp.h>
#include <linux/spinlock.h>
#include <asm/system.h> /* xchg */
#include <asm/time.h> /* timer_interrupt */
#include <asm/hexagon_vm.h>
#define BASE_IPI_IRQ 26
/*
* cpu_possible_map needs to be filled out prior to setup_per_cpu_areas
* (which is prior to any of our smp_prepare_cpu crap), in order to set
* up the... per_cpu areas.
*/
struct ipi_data {
unsigned long bits;
};
static DEFINE_PER_CPU(struct ipi_data, ipi_data);
static inline void __handle_ipi(unsigned long *ops, struct ipi_data *ipi,
int cpu)
{
unsigned long msg = 0;
do {
msg = find_next_bit(ops, BITS_PER_LONG, msg+1);
switch (msg) {
case IPI_TIMER:
ipi_timer();
break;
case IPI_CALL_FUNC:
generic_smp_call_function_interrupt();
break;
case IPI_CALL_FUNC_SINGLE:
generic_smp_call_function_single_interrupt();
break;
case IPI_CPU_STOP:
/*
* call vmstop()
*/
__vmstop();
break;
case IPI_RESCHEDULE:
scheduler_ipi();
break;
}
} while (msg < BITS_PER_LONG);
}
/* Used for IPI call from other CPU's to unmask int */
void smp_vm_unmask_irq(void *info)
{
__vmintop_locen((long) info);
}
/*
* This is based on Alpha's IPI stuff.
* Supposed to take (int, void*) as args now.
* Specifically, first arg is irq, second is the irq_desc.
*/
irqreturn_t handle_ipi(int irq, void *desc)
{
int cpu = smp_processor_id();
struct ipi_data *ipi = &per_cpu(ipi_data, cpu);
unsigned long ops;
while ((ops = xchg(&ipi->bits, 0)) != 0)
__handle_ipi(&ops, ipi, cpu);
return IRQ_HANDLED;
}
void send_ipi(const struct cpumask *cpumask, enum ipi_message_type msg)
{
unsigned long flags;
unsigned long cpu;
unsigned long retval;
local_irq_save(flags);
for_each_cpu(cpu, cpumask) {
struct ipi_data *ipi = &per_cpu(ipi_data, cpu);
set_bit(msg, &ipi->bits);
/* Possible barrier here */
retval = __vmintop_post(BASE_IPI_IRQ+cpu);
if (retval != 0) {
printk(KERN_ERR "interrupt %ld not configured?\n",
BASE_IPI_IRQ+cpu);
}
}
local_irq_restore(flags);
}
static struct irqaction ipi_intdesc = {
.handler = handle_ipi,
.flags = IRQF_TRIGGER_RISING,
.name = "ipi_handler"
};
void __init smp_prepare_boot_cpu(void)
{
}
/*
* interrupts should already be disabled from the VM
* SP should already be correct; need to set THREADINFO_REG
* to point to current thread info
*/
void __cpuinit start_secondary(void)
{
unsigned int cpu;
unsigned long thread_ptr;
/* Calculate thread_info pointer from stack pointer */
__asm__ __volatile__(
"%0 = SP;\n"
: "=r" (thread_ptr)
);
thread_ptr = thread_ptr & ~(THREAD_SIZE-1);
__asm__ __volatile__(
QUOTED_THREADINFO_REG " = %0;\n"
:
: "r" (thread_ptr)
);
/* Set the memory struct */
atomic_inc(&init_mm.mm_count);
current->active_mm = &init_mm;
cpu = smp_processor_id();
setup_irq(BASE_IPI_IRQ + cpu, &ipi_intdesc);
/* Register the clock_event dummy */
setup_percpu_clockdev();
printk(KERN_INFO "%s cpu %d\n", __func__, current_thread_info()->cpu);
set_cpu_online(cpu, true);
while (!cpumask_test_cpu(cpu, cpu_active_mask))
cpu_relax();
local_irq_enable();
cpu_idle();
}
/*
* called once for each present cpu
* apparently starts up the CPU and then
* maintains control until "cpu_online(cpu)" is set.
*/
int __cpuinit __cpu_up(unsigned int cpu)
{
struct task_struct *idle;
struct thread_info *thread;
void *stack_start;
/* Create new init task for the CPU */
idle = fork_idle(cpu);
if (IS_ERR(idle))
panic(KERN_ERR "fork_idle failed\n");
thread = (struct thread_info *)idle->stack;
thread->cpu = cpu;
/* Boot to the head. */
stack_start = ((void *) thread) + THREAD_SIZE;
__vmstart(start_secondary, stack_start);
while (!cpu_isset(cpu, cpu_online_map))
barrier();
return 0;
}
void __init smp_cpus_done(unsigned int max_cpus)
{
}
void __init smp_prepare_cpus(unsigned int max_cpus)
{
int i;
/*
* should eventually have some sort of machine
* descriptor that has this stuff
*/
/* Right now, let's just fake it. */
for (i = 0; i < max_cpus; i++)
cpu_set(i, cpu_present_map);
/* Also need to register the interrupts for IPI */
if (max_cpus > 1)
setup_irq(BASE_IPI_IRQ, &ipi_intdesc);
}
void smp_send_reschedule(int cpu)
{
send_ipi(cpumask_of(cpu), IPI_RESCHEDULE);
}
void smp_send_stop(void)
{
struct cpumask targets;
cpumask_copy(&targets, cpu_online_mask);
cpumask_clear_cpu(smp_processor_id(), &targets);
send_ipi(&targets, IPI_CPU_STOP);
}
void arch_send_call_function_single_ipi(int cpu)
{
send_ipi(cpumask_of(cpu), IPI_CALL_FUNC_SINGLE);
}
void arch_send_call_function_ipi_mask(const struct cpumask *mask)
{
send_ipi(mask, IPI_CALL_FUNC);
}
int setup_profiling_timer(unsigned int multiplier)
{
return -EINVAL;
}
void smp_start_cpus(void)
{
int i;
for (i = 0; i < NR_CPUS; i++)
cpu_set(i, cpu_possible_map);
}

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/*
* CPU topology for Hexagon
*
* Copyright (c) 2010-2011, Code Aurora Forum. 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 and
* only version 2 as published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
* 02110-1301, USA.
*/
#include <linux/cpu.h>
#include <linux/cpumask.h>
#include <linux/init.h>
#include <linux/node.h>
#include <linux/nodemask.h>
#include <linux/percpu.h>
/* Swiped from MIPS. */
static DEFINE_PER_CPU(struct cpu, cpu_devices);
static int __init topology_init(void)
{
int i, ret;
for_each_present_cpu(i) {
/*
* register_cpu takes a per_cpu pointer and
* just points it at another per_cpu struct...
*/
ret = register_cpu(&per_cpu(cpu_devices, i), i);
if (ret)
printk(KERN_WARNING "topology_init: register_cpu %d "
"failed (%d)\n", i, ret);
}
return 0;
}
subsys_initcall(topology_init);