smp.c

linux-2.6.15.6

/*
 *  linux/arch/m32r/kernel/smp.c
 *
 *  M32R SMP support routines.
 *
 *  Copyright (c) 2001, 2002  Hitoshi Yamamoto
 *
 *  Taken from i386 version.
 *    (c) 1995 Alan Cox, Building #3 <[e-mail]>
 *    (c) 1998-99, 2000 Ingo Molnar <[e-mail]>
 *
 *  This code is released under the GNU General Public License version 2 or
 *  later.
 */

#undef DEBUG_SMP

#include <linux/irq.h>
#include <linux/interrupt.h>
#include <linux/spinlock.h>
#include <linux/mm.h>
#include <linux/smp.h>
#include <linux/profile.h>
#include <linux/cpu.h>

#include <asm/cacheflush.h>
#include <asm/pgalloc.h>
#include <asm/atomic.h>
#include <asm/io.h>
#include <asm/mmu_context.h>
#include <asm/m32r.h>

/*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*/
/* Data structures and variables                                             */
/*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*/

/*
 * Structure and data for smp_call_function(). This is designed to minimise
 * static memory requirements. It also looks cleaner.
 */
static DEFINE_SPINLOCK(call_lock);

struct call_data_struct {
	void (*func) (void *info);
	void *info;
	atomic_t started;
	atomic_t finished;
	int wait;
} __attribute__ ((__aligned__(SMP_CACHE_BYTES)));

static struct call_data_struct *call_data;

/*
 * For flush_cache_all()
 */
static DEFINE_SPINLOCK(flushcache_lock);
static volatile unsigned long flushcache_cpumask = 0;

/*
 * For flush_tlb_others()
 */
static volatile cpumask_t flush_cpumask;
static struct mm_struct *flush_mm;
static struct vm_area_struct *flush_vma;
static volatile unsigned long flush_va;
static DEFINE_SPINLOCK(tlbstate_lock);
#define FLUSH_ALL 0xffffffff

DECLARE_PER_CPU(int, prof_multiplier);
DECLARE_PER_CPU(int, prof_old_multiplier);
DECLARE_PER_CPU(int, prof_counter);

extern spinlock_t ipi_lock[];

/*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*/
/* Function Prototypes                                                       */
/*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*/

void smp_send_reschedule(int);
void smp_reschedule_interrupt(void);

void smp_flush_cache_all(void);
void smp_flush_cache_all_interrupt(void);

void smp_flush_tlb_all(void);
static void flush_tlb_all_ipi(void *);

void smp_flush_tlb_mm(struct mm_struct *);
void smp_flush_tlb_range(struct vm_area_struct *, unsigned long, \
	unsigned long);
void smp_flush_tlb_page(struct vm_area_struct *, unsigned long);
static void flush_tlb_others(cpumask_t, struct mm_struct *,
	struct vm_area_struct *, unsigned long);
void smp_invalidate_interrupt(void);

void smp_send_stop(void);
static void stop_this_cpu(void *);

int smp_call_function(void (*) (void *), void *, int, int);
void smp_call_function_interrupt(void);

void smp_send_timer(void);
void smp_ipi_timer_interrupt(struct pt_regs *);
void smp_local_timer_interrupt(struct pt_regs *);

void send_IPI_allbutself(int, int);
static void send_IPI_mask(cpumask_t, int, int);
unsigned long send_IPI_mask_phys(cpumask_t, int, int);

/*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*/
/* Rescheduling request Routines                                             */
/*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*/

/*==========================================================================*
 * Name:         smp_send_reschedule
 *
 * Description:  This routine requests other CPU to execute rescheduling.
 *               1.Send 'RESCHEDULE_IPI' to other CPU.
 *                 Request other CPU to execute 'smp_reschedule_interrupt()'.
 *
 * Born on Date: 2002.02.05
 *
 * Arguments:    cpu_id - Target CPU ID
 *
 * Returns:      void (cannot fail)
 *
 * Modification log:
 * Date       Who Description
 * ---------- --- --------------------------------------------------------
 *
 *==========================================================================*/
void smp_send_reschedule(int cpu_id)
{
	WARN_ON(cpu_is_offline(cpu_id));
	send_IPI_mask(cpumask_of_cpu(cpu_id), RESCHEDULE_IPI, 1);
}

/*==========================================================================*
 * Name:         smp_reschedule_interrupt
 *
 * Description:  This routine executes on CPU which received
 *               'RESCHEDULE_IPI'.
 *               Rescheduling is processed at the exit of interrupt
 *               operation.
 *
 * Born on Date: 2002.02.05
 *
 * Arguments:    NONE
 *
 * Returns:      void (cannot fail)
 *
 * Modification log:
 * Date       Who Description
 * ---------- --- --------------------------------------------------------
 *
 *==========================================================================*/
void smp_reschedule_interrupt(void)
{
	/* nothing to do */
}

/*==========================================================================*
 * Name:         smp_flush_cache_all
 *
 * Description:  This routine sends a 'INVALIDATE_CACHE_IPI' to all other
 *               CPUs in the system.
 *
 * Born on Date: 2003-05-28
 *
 * Arguments:    NONE
 *
 * Returns:      void (cannot fail)
 *
 * Modification log:
 * Date       Who Description
 * ---------- --- --------------------------------------------------------
 *
 *==========================================================================*/
void smp_flush_cache_all(void)
{
	cpumask_t cpumask;
	unsigned long *mask;

	preempt_disable();
	cpumask = cpu_online_map;
	cpu_clear(smp_processor_id(), cpumask);
	spin_lock(&flushcache_lock);
	mask=cpus_addr(cpumask);
	atomic_set_mask(*mask, (atomic_t *)&flushcache_cpumask);
	send_IPI_mask(cpumask, INVALIDATE_CACHE_IPI, 0);
	_flush_cache_copyback_all();
	while (flushcache_cpumask)
		mb();
	spin_unlock(&flushcache_lock);
	preempt_enable();
}

void smp_flush_cache_all_interrupt(void)
{
	_flush_cache_copyback_all();
	clear_bit(smp_processor_id(), &flushcache_cpumask);
}

/*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*/
/* TLB flush request Routins                                                 */
/*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*/

/*==========================================================================*
 * Name:         smp_flush_tlb_all
 *
 * Description:  This routine flushes all processes TLBs.
 *               1.Request other CPU to execute 'flush_tlb_all_ipi()'.
 *               2.Execute 'do_flush_tlb_all_local()'.
 *
 * Born on Date: 2002.02.05
 *
 * Arguments:    NONE
 *
 * Returns:      void (cannot fail)
 *
 * Modification log:
 * Date       Who Description
 * ---------- --- --------------------------------------------------------
 *
 *==========================================================================*/
void smp_flush_tlb_all(void)
{
	unsigned long flags;

	preempt_disable();
	local_irq_save(flags);
	__flush_tlb_all();
	local_irq_restore(flags);
	smp_call_function(flush_tlb_all_ipi, 0, 1, 1);
	preempt_enable();
}

/*==========================================================================*
 * Name:         flush_tlb_all_ipi
 *
 * Description:  This routine flushes all local TLBs.
 *               1.Execute 'do_flush_tlb_all_local()'.
 *
 * Born on Date: 2002.02.05
 *
 * Arguments:    *info - not used
 *
 * Returns:      void (cannot fail)
 *
 * Modification log:
 * Date       Who Description
 * ---------- --- --------------------------------------------------------
 *
 *==========================================================================*/
static void flush_tlb_all_ipi(void *info)
{
	__flush_tlb_all();
}

/*==========================================================================*
 * Name:         smp_flush_tlb_mm
 *
 * Description:  This routine flushes the specified mm context TLB's.
 *
 * Born on Date: 2002.02.05
 *
 * Arguments:    *mm - a pointer to the mm struct for flush TLB
 *
 * Returns:      void (cannot fail)
 *
 * Modification log:
 * Date       Who Description
 * ---------- --- --------------------------------------------------------
 *
 *==========================================================================*/
void smp_flush_tlb_mm(struct mm_struct *mm)
{
	int cpu_id;
	cpumask_t cpu_mask;
	unsigned long *mmc;
	unsigned long flags;

	preempt_disable();
	cpu_id = smp_processor_id();
	mmc = &mm->context[cpu_id];
	cpu_mask = mm->cpu_vm_mask;
	cpu_clear(cpu_id, cpu_mask);

	if (*mmc != NO_CONTEXT) {
		local_irq_save(flags);
		*mmc = NO_CONTEXT;
		if (mm == current->mm)
			activate_context(mm);
		else
			cpu_clear(cpu_id, mm->cpu_vm_mask);
		local_irq_restore(flags);
	}
	if (!cpus_empty(cpu_mask))
		flush_tlb_others(cpu_mask, mm, NULL, FLUSH_ALL);

	preempt_enable();
}

/*==========================================================================*
 * Name:         smp_flush_tlb_range
 *
 * Description:  This routine flushes a range of pages.
 *
 * Born on Date: 2002.02.05
 *
 * Arguments:    *mm - a pointer to the mm struct for flush TLB
 *               start - not used
 *               end - not used
 *
 * Returns:      void (cannot fail)
 *
 * Modification log:
 * Date       Who Description
 * ---------- --- --------------------------------------------------------
 *
 *==========================================================================*/
void smp_flush_tlb_range(struct vm_area_struct *vma, unsigned long start,
	unsigned long end)
{
	smp_flush_tlb_mm(vma->vm_mm);
}

/*==========================================================================*
 * Name:         smp_flush_tlb_page
 *
 * Description:  This routine flushes one page.
 *
 * Born on Date: 2002.02.05
 *
 * Arguments:    *vma - a pointer to the vma struct include va
 *               va - virtual address for flush TLB
 *
 * Returns:      void (cannot fail)
 *
 * Modification log:
 * Date       Who Description
 * ---------- --- --------------------------------------------------------
 *
 *==========================================================================*/
void smp_flush_tlb_page(struct vm_area_struct *vma, unsigned long va)
{
	struct mm_struct *mm = vma->vm_mm;
	int cpu_id;
	cpumask_t cpu_mask;
	unsigned long *mmc;
	unsigned long flags;

	preempt_disable();
	cpu_id = smp_processor_id();
	mmc = &mm->context[cpu_id];
	cpu_mask = mm->cpu_vm_mask;
	cpu_clear(cpu_id, cpu_mask);

#ifdef DEBUG_SMP
	if (!mm)
		BUG();
#endif

	if (*mmc != NO_CONTEXT) {
		local_irq_save(flags);
		va &= PAGE_MASK;
		va |= (*mmc & MMU_CONTEXT_ASID_MASK);
		__flush_tlb_page(va);
		local_irq_restore(flags);
	}
	if (!cpus_empty(cpu_mask))
		flush_tlb_others(cpu_mask, mm, vma, va);

	preempt_enable();
}

/*==========================================================================*
 * Name:         flush_tlb_others
 *
 * Description:  This routine requests other CPU to execute flush TLB.
 *               1.Setup parmeters.
 *               2.Send 'INVALIDATE_TLB_IPI' to other CPU.
 *                 Request other CPU to execute 'smp_invalidate_interrupt()'.
 *               3.Wait for other CPUs operation finished.
 *
 * Born on Date: 2002.02.05
 *
 * Arguments:    cpumask - bitmap of target CPUs
 *               *mm -  a pointer to the mm struct for flush TLB
 *               *vma -  a pointer to the vma struct include va
 *               va - virtual address for flush TLB
 *
 * Returns:      void (cannot fail)
 *
 * Modification log:
 * Date       Who Description
 * ---------- --- --------------------------------------------------------
 *
 *==========================================================================*/
static void flush_tlb_others(cpumask_t cpumask, struct mm_struct *mm,
	struct vm_area_struct *vma, unsigned long va)
{
	unsigned long *mask;
#ifdef DEBUG_SMP
	unsigned long flags;
	__save_flags(flags);
	if (!(flags & 0x0040))	/* Interrupt Disable NONONO */
		BUG();
#endif /* DEBUG_SMP */

	/*
	 * A couple of (to be removed) sanity checks:
	 *
	 * - we do not send IPIs to not-yet booted CPUs.
	 * - current CPU must not be in mask
	 * - mask must exist :)
	 */
	BUG_ON(cpus_empty(cpumask));

	BUG_ON(cpu_isset(smp_processor_id(), cpumask));
	BUG_ON(!mm);

	/* If a CPU which we ran on has gone down, OK. */
	cpus_and(cpumask, cpumask, cpu_online_map);
	if (cpus_empty(cpumask))
		return;

	/*
	 * i'm not happy about this global shared spinlock in the
	 * MM hot path, but we'll see how contended it is.
	 * Temporarily this turns IRQs off, so that lockups are
	 * detected by the NMI watchdog.
	 */
	spin_lock(&tlbstate_lock);

	flush_mm = mm;
	flush_vma = vma;
	flush_va = va;
	mask=cpus_addr(cpumask);
	atomic_set_mask(*mask, (atomic_t *)&flush_cpumask);

	/*
	 * We have to send the IPI only to
	 * CPUs affected.
	 */
	send_IPI_mask(cpumask, INVALIDATE_TLB_IPI, 0);

	while (!cpus_empty(flush_cpumask)) {
		/* nothing. lockup detection does not belong here */
		mb();
	}

	flush_mm = NULL;
	flush_vma = NULL;
	flush_va = 0;
	spin_unlock(&tlbstate_lock);
}

/*==========================================================================*
 * Name:         smp_invalidate_interrupt
 *
 * Description:  This routine executes on CPU which received
 *               'INVALIDATE_TLB_IPI'.
 *               1.Flush local TLB.
 *               2.Report flush TLB process was finished.
 *
 * Born on Date: 2002.02.05
 *
 * Arguments:    NONE
 *
 * Returns:      void (cannot fail)
 *
 * Modification log: