spinlock.c File Reference

#include <stdbool.h>
#include <stdint.h>
#include <string.h>
#include <sys/kassert.h>
#include <sys/kconfig.h>
#include <sys/kdebug.h>
#include <sys/ktime.h>
#include <sys/mp.h>
#include <sys/spinlock.h>
#include <machine/atomic.h>
#include <machine/amd64.h>
#include <machine/amd64op.h>

Include dependency graph for spinlock.c:

Go to the source code of this file.

Functions
	LIST_HEAD (LockListHead, Spinlock)
void	Spinlock_Init (Spinlock *lock, const char *name, uint64_t type)
void	Spinlock_Destroy (Spinlock *lock)
void	Spinlock_Lock (Spinlock *lock) __NO_LOCK_ANALYSIS
void	Spinlock_Unlock (Spinlock *lock) __NO_LOCK_ANALYSIS
bool	Spinlock_IsHeld (Spinlock *lock)
void	Debug_Spinlocks (int argc, const char *argv[])
	REGISTER_DBGCMD (spinlocks, "Display list of spinlocks", Debug_Spinlocks)
void	Debug_LockStack (int argc, const char *argv[])
	REGISTER_DBGCMD (lockstack, "Display stack of held spinlocks", Debug_LockStack)

Variables
Spinlock	lockListLock

Function Documentation

Debug_LockStack()

void Debug_LockStack	(	int	argc,
		const char *	argv[]
	)

Definition at line 152 of file spinlock.c.

{
    int c = CPU();
    Spinlock *lock;
 
    kprintf("Lock Stack:\n");
    TAILQ_FOREACH(lock, &lockStack[c], lockStack) {
        kprintf("    %s\n", lock->name);
    }
}

Here is the call graph for this function:

Debug_Spinlocks()

void Debug_Spinlocks	(	int	argc,
		const char *	argv[]
	)

Definition at line 132 of file spinlock.c.

{
    Spinlock *lock;
 
    Spinlock_Lock(&lockListLock);
 
    kprintf("%-36s Locked CPU    Count     WaitTime     LockTime\n", "Lock Name");
    LIST_FOREACH(lock, &lockList, lockList)
    {
        kprintf("%-36s %6llu %3llu %8llu %12llu %12llu\n", lock->name,
                lock->lock, lock->cpu, lock->count,
                lock->waitTime, lock->lockTime);
    }
 
    Spinlock_Unlock(&lockListLock);
}

Here is the call graph for this function:

LIST_HEAD()

LIST_HEAD	(	LockListHead	,
		Spinlock
	)

Definition at line 26 of file spinlock.c.

{
    int c;
 
    for (c = 0; c < MAX_CPUS; c++) {
        TAILQ_INIT(&lockStack[c]);
    }
}

REGISTER_DBGCMD() [1/2]

REGISTER_DBGCMD	(	lockstack	,
		"Display stack of held spinlocks"	,
		Debug_LockStack
	)

REGISTER_DBGCMD() [2/2]

REGISTER_DBGCMD	(	spinlocks	,
		"Display list of spinlocks"	,
		Debug_Spinlocks
	)

Spinlock_Destroy()

void Spinlock_Destroy

(

Spinlock *

lock

)

Definition at line 61 of file spinlock.c.

{
    Spinlock_Lock(&lockListLock);
    LIST_REMOVE(lock, lockList);
    Spinlock_Unlock(&lockListLock);
}

Here is the call graph for this function:

Here is the caller graph for this function:

Spinlock_Init()

void Spinlock_Init	(	Spinlock *	lock,
		const char *	name,
		uint64_t	type
	)

Definition at line 43 of file spinlock.c.

{
    lock->lock = 0;
    lock->cpu = 0;
    lock->count = 0;
    lock->rCount = 0;
    lock->lockTime = 0;
    lock->waitTime = 0;
    lock->type = type;
 
    strncpy(&lock->name[0], name, SPINLOCK_NAMELEN);
 
    Spinlock_Lock(&lockListLock);
    LIST_INSERT_HEAD(&lockList, lock, lockList);
    Spinlock_Unlock(&lockListLock);
}

Here is the call graph for this function:

Here is the caller graph for this function:

Spinlock_IsHeld()

bool Spinlock_IsHeld

(

Spinlock *

lock

)

Definition at line 126 of file spinlock.c.

{
    return (lock->cpu == CPU()) && (lock->lock == 1);
}

Here is the caller graph for this function:

Spinlock_Lock()

void Spinlock_Lock

(

Spinlock *

lock

)

Spinlock_Lock –

Spin until we acquire the spinlock. This will also disable interrupts to prevent deadlocking with interrupt handlers.

Definition at line 75 of file spinlock.c.

{
    uint64_t startTSC;
    Critical_Enter();
 
    startTSC = Time_GetTSC();
    while (atomic_swap_uint64(&lock->lock, 1) == 1)
    {
        if (lock->type == SPINLOCK_TYPE_RECURSIVE && lock->cpu == CPU()) {
            break;
        }
        if ((Time_GetTSC() - startTSC) / ticksPerSecond > 1) {
            kprintf("Spinlock_Lock(%s): waiting for over a second!\n", lock->name);
            breakpoint();
        }
    }
    lock->waitTime += Time_GetTSC() - startTSC;
 
    lock->cpu = CPU();
    lock->count++;
 
    lock->rCount++;
    if (lock->rCount == 1)
        lock->lockedTSC = Time_GetTSC();
 
    TAILQ_INSERT_TAIL(&lockStack[CPU()], lock, lockStack);
}

Here is the call graph for this function:

Spinlock_Unlock()

void Spinlock_Unlock

(

Spinlock *

lock

)

Spinlock_Unlock –

Release the spinlock. This will re-enable interrupts.

Definition at line 109 of file spinlock.c.

{
    ASSERT(lock->cpu == CPU());
 
    TAILQ_REMOVE(&lockStack[CPU()], lock, lockStack);
 
    lock->rCount--;
    if (lock->rCount == 0) {
        lock->cpu = 0;
        lock->lockTime += Time_GetTSC() - lock->lockedTSC;
        atomic_set_uint64(&lock->lock, 0);
    }
 
    Critical_Exit();
}

Here is the call graph for this function:

Variable Documentation

lockListLock

Spinlock lockListLock

Initial value:

= {
    0, 0, 0, 0, 0, 0, 0,
    SPINLOCK_TYPE_NORMAL,
    "SPINLOCK LIST",
}

Definition at line 21 of file spinlock.c.