ce7599567e
The __cpuinit type of throwaway sections might have made sense
some time ago when RAM was more constrained, but now the savings
do not offset the cost and complications. For example, the fix in
commit 5e427ec2d0 ("x86: Fix bit corruption at CPU resume time")
is a good example of the nasty type of bugs that can be created
with improper use of the various __init prefixes.
After a discussion on LKML[1] it was decided that cpuinit should go
the way of devinit and be phased out. Once all the users are gone,
we can then finally remove the macros themselves from linux/init.h.
Note that some harmless section mismatch warnings may result, since
notify_cpu_starting() and cpu_up() are arch independent (kernel/cpu.c)
are flagged as __cpuinit -- so if we remove the __cpuinit from
arch specific callers, we will also get section mismatch warnings.
As an intermediate step, we intend to turn the linux/init.h cpuinit
content into no-ops as early as possible, since that will get rid
of these warnings. In any case, they are temporary and harmless.
This removes all the arch/arc uses of the __cpuinit macros from
all C files. Currently arc does not have any __CPUINIT used in
assembly files.
[1] https://lkml.org/lkml/2013/5/20/589
Cc: Vineet Gupta <vgupta@synopsys.com>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
333 lines
7.5 KiB
C
333 lines
7.5 KiB
C
/*
|
|
* Copyright (C) 2004, 2007-2010, 2011-2012 Synopsys, Inc. (www.synopsys.com)
|
|
*
|
|
* 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.
|
|
*
|
|
* RajeshwarR: Dec 11, 2007
|
|
* -- Added support for Inter Processor Interrupts
|
|
*
|
|
* Vineetg: Nov 1st, 2007
|
|
* -- Initial Write (Borrowed heavily from ARM)
|
|
*/
|
|
|
|
#include <linux/module.h>
|
|
#include <linux/init.h>
|
|
#include <linux/spinlock.h>
|
|
#include <linux/sched.h>
|
|
#include <linux/interrupt.h>
|
|
#include <linux/profile.h>
|
|
#include <linux/errno.h>
|
|
#include <linux/err.h>
|
|
#include <linux/mm.h>
|
|
#include <linux/cpu.h>
|
|
#include <linux/smp.h>
|
|
#include <linux/irq.h>
|
|
#include <linux/delay.h>
|
|
#include <linux/atomic.h>
|
|
#include <linux/percpu.h>
|
|
#include <linux/cpumask.h>
|
|
#include <linux/spinlock_types.h>
|
|
#include <linux/reboot.h>
|
|
#include <asm/processor.h>
|
|
#include <asm/setup.h>
|
|
#include <asm/mach_desc.h>
|
|
|
|
arch_spinlock_t smp_atomic_ops_lock = __ARCH_SPIN_LOCK_UNLOCKED;
|
|
arch_spinlock_t smp_bitops_lock = __ARCH_SPIN_LOCK_UNLOCKED;
|
|
|
|
struct plat_smp_ops plat_smp_ops;
|
|
|
|
/* XXX: per cpu ? Only needed once in early seconday boot */
|
|
struct task_struct *secondary_idle_tsk;
|
|
|
|
/* Called from start_kernel */
|
|
void __init smp_prepare_boot_cpu(void)
|
|
{
|
|
}
|
|
|
|
/*
|
|
* Initialise the CPU possible map early - this describes the CPUs
|
|
* which may be present or become present in the system.
|
|
*/
|
|
void __init smp_init_cpus(void)
|
|
{
|
|
unsigned int i;
|
|
|
|
for (i = 0; i < NR_CPUS; i++)
|
|
set_cpu_possible(i, true);
|
|
}
|
|
|
|
/* called from init ( ) => process 1 */
|
|
void __init smp_prepare_cpus(unsigned int max_cpus)
|
|
{
|
|
int i;
|
|
|
|
/*
|
|
* Initialise the present map, which describes the set of CPUs
|
|
* actually populated at the present time.
|
|
*/
|
|
for (i = 0; i < max_cpus; i++)
|
|
set_cpu_present(i, true);
|
|
}
|
|
|
|
void __init smp_cpus_done(unsigned int max_cpus)
|
|
{
|
|
|
|
}
|
|
|
|
/*
|
|
* After power-up, a non Master CPU needs to wait for Master to kick start it
|
|
*
|
|
* The default implementation halts
|
|
*
|
|
* This relies on platform specific support allowing Master to directly set
|
|
* this CPU's PC (to be @first_lines_of_secondary() and kick start it.
|
|
*
|
|
* In lack of such h/w assist, platforms can override this function
|
|
* - make this function busy-spin on a token, eventually set by Master
|
|
* (from arc_platform_smp_wakeup_cpu())
|
|
* - Once token is available, jump to @first_lines_of_secondary
|
|
* (using inline asm).
|
|
*
|
|
* Alert: can NOT use stack here as it has not been determined/setup for CPU.
|
|
* If it turns out to be elaborate, it's better to code it in assembly
|
|
*
|
|
*/
|
|
void __attribute__((weak)) arc_platform_smp_wait_to_boot(int cpu)
|
|
{
|
|
/*
|
|
* As a hack for debugging - since debugger will single-step over the
|
|
* FLAG insn - wrap the halt itself it in a self loop
|
|
*/
|
|
__asm__ __volatile__(
|
|
"1: \n"
|
|
" flag 1 \n"
|
|
" b 1b \n");
|
|
}
|
|
|
|
const char *arc_platform_smp_cpuinfo(void)
|
|
{
|
|
return plat_smp_ops.info;
|
|
}
|
|
|
|
/*
|
|
* The very first "C" code executed by secondary
|
|
* Called from asm stub in head.S
|
|
* "current"/R25 already setup by low level boot code
|
|
*/
|
|
void start_kernel_secondary(void)
|
|
{
|
|
struct mm_struct *mm = &init_mm;
|
|
unsigned int cpu = smp_processor_id();
|
|
|
|
/* MMU, Caches, Vector Table, Interrupts etc */
|
|
setup_processor();
|
|
|
|
atomic_inc(&mm->mm_users);
|
|
atomic_inc(&mm->mm_count);
|
|
current->active_mm = mm;
|
|
|
|
notify_cpu_starting(cpu);
|
|
set_cpu_online(cpu, true);
|
|
|
|
pr_info("## CPU%u LIVE ##: Executing Code...\n", cpu);
|
|
|
|
if (machine_desc->init_smp)
|
|
machine_desc->init_smp(smp_processor_id());
|
|
|
|
arc_local_timer_setup(cpu);
|
|
|
|
local_irq_enable();
|
|
preempt_disable();
|
|
cpu_startup_entry(CPUHP_ONLINE);
|
|
}
|
|
|
|
/*
|
|
* Called from kernel_init( ) -> smp_init( ) - for each CPU
|
|
*
|
|
* At this point, Secondary Processor is "HALT"ed:
|
|
* -It booted, but was halted in head.S
|
|
* -It was configured to halt-on-reset
|
|
* So need to wake it up.
|
|
*
|
|
* Essential requirements being where to run from (PC) and stack (SP)
|
|
*/
|
|
int __cpu_up(unsigned int cpu, struct task_struct *idle)
|
|
{
|
|
unsigned long wait_till;
|
|
|
|
secondary_idle_tsk = idle;
|
|
|
|
pr_info("Idle Task [%d] %p", cpu, idle);
|
|
pr_info("Trying to bring up CPU%u ...\n", cpu);
|
|
|
|
if (plat_smp_ops.cpu_kick)
|
|
plat_smp_ops.cpu_kick(cpu,
|
|
(unsigned long)first_lines_of_secondary);
|
|
|
|
/* wait for 1 sec after kicking the secondary */
|
|
wait_till = jiffies + HZ;
|
|
while (time_before(jiffies, wait_till)) {
|
|
if (cpu_online(cpu))
|
|
break;
|
|
}
|
|
|
|
if (!cpu_online(cpu)) {
|
|
pr_info("Timeout: CPU%u FAILED to comeup !!!\n", cpu);
|
|
return -1;
|
|
}
|
|
|
|
secondary_idle_tsk = NULL;
|
|
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* not supported here
|
|
*/
|
|
int __init setup_profiling_timer(unsigned int multiplier)
|
|
{
|
|
return -EINVAL;
|
|
}
|
|
|
|
/*****************************************************************************/
|
|
/* Inter Processor Interrupt Handling */
|
|
/*****************************************************************************/
|
|
|
|
/*
|
|
* structures for inter-processor calls
|
|
* A Collection of single bit ipi messages
|
|
*
|
|
*/
|
|
|
|
/*
|
|
* TODO_rajesh investigate tlb message types.
|
|
* IPI Timer not needed because each ARC has an individual Interrupting Timer
|
|
*/
|
|
enum ipi_msg_type {
|
|
IPI_NOP = 0,
|
|
IPI_RESCHEDULE = 1,
|
|
IPI_CALL_FUNC,
|
|
IPI_CALL_FUNC_SINGLE,
|
|
IPI_CPU_STOP
|
|
};
|
|
|
|
struct ipi_data {
|
|
unsigned long bits;
|
|
};
|
|
|
|
static DEFINE_PER_CPU(struct ipi_data, ipi_data);
|
|
|
|
static void ipi_send_msg(const struct cpumask *callmap, enum ipi_msg_type msg)
|
|
{
|
|
unsigned long flags;
|
|
unsigned int cpu;
|
|
|
|
local_irq_save(flags);
|
|
|
|
for_each_cpu(cpu, callmap) {
|
|
struct ipi_data *ipi = &per_cpu(ipi_data, cpu);
|
|
set_bit(msg, &ipi->bits);
|
|
}
|
|
|
|
/* Call the platform specific cross-CPU call function */
|
|
if (plat_smp_ops.ipi_send)
|
|
plat_smp_ops.ipi_send((void *)callmap);
|
|
|
|
local_irq_restore(flags);
|
|
}
|
|
|
|
void smp_send_reschedule(int cpu)
|
|
{
|
|
ipi_send_msg(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);
|
|
ipi_send_msg(&targets, IPI_CPU_STOP);
|
|
}
|
|
|
|
void arch_send_call_function_single_ipi(int cpu)
|
|
{
|
|
ipi_send_msg(cpumask_of(cpu), IPI_CALL_FUNC_SINGLE);
|
|
}
|
|
|
|
void arch_send_call_function_ipi_mask(const struct cpumask *mask)
|
|
{
|
|
ipi_send_msg(mask, IPI_CALL_FUNC);
|
|
}
|
|
|
|
/*
|
|
* ipi_cpu_stop - handle IPI from smp_send_stop()
|
|
*/
|
|
static void ipi_cpu_stop(unsigned int cpu)
|
|
{
|
|
machine_halt();
|
|
}
|
|
|
|
static inline void __do_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_RESCHEDULE:
|
|
scheduler_ipi();
|
|
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:
|
|
ipi_cpu_stop(cpu);
|
|
break;
|
|
}
|
|
} while (msg < BITS_PER_LONG);
|
|
|
|
}
|
|
|
|
/*
|
|
* arch-common ISR to handle for inter-processor interrupts
|
|
* Has hooks for platform specific IPI
|
|
*/
|
|
irqreturn_t do_IPI(int irq, void *dev_id)
|
|
{
|
|
int cpu = smp_processor_id();
|
|
struct ipi_data *ipi = &per_cpu(ipi_data, cpu);
|
|
unsigned long ops;
|
|
|
|
if (plat_smp_ops.ipi_clear)
|
|
plat_smp_ops.ipi_clear(cpu, irq);
|
|
|
|
/*
|
|
* XXX: is this loop really needed
|
|
* And do we need to move ipi_clean inside
|
|
*/
|
|
while ((ops = xchg(&ipi->bits, 0)) != 0)
|
|
__do_IPI(&ops, ipi, cpu);
|
|
|
|
return IRQ_HANDLED;
|
|
}
|
|
|
|
/*
|
|
* API called by platform code to hookup arch-common ISR to their IPI IRQ
|
|
*/
|
|
static DEFINE_PER_CPU(int, ipi_dev);
|
|
int smp_ipi_irq_setup(int cpu, int irq)
|
|
{
|
|
int *dev_id = &per_cpu(ipi_dev, smp_processor_id());
|
|
return request_percpu_irq(irq, do_IPI, "IPI Interrupt", dev_id);
|
|
}
|