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Commit 24140594 authored by Christoph Hellwig's avatar Christoph Hellwig Committed by Arnd Bergmann
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[CELL] spu_base: locking cleanup 



Sort out the locking mess in spu_base and document the current rules.
As an added benefit spu_alloc* and spu_free don't block anymore.

Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
Signed-off-by: default avatarArnd Bergmann <arnd.bergmann@de.ibm.com>
parent 9e7cbcbb

arch/powerpc/platforms/cell/spu_base.c

+51 −33
Original line number Diff line number Diff line
@@ -42,12 +42,30 @@ const struct spu_management_ops *spu_management_ops; 
EXPORT_SYMBOL_GPL(spu_management_ops);



const struct spu_priv1_ops *spu_priv1_ops;

EXPORT_SYMBOL_GPL(spu_priv1_ops);



static LIST_HEAD(spu_full_list);

static DEFINE_MUTEX(spu_mutex);

static DEFINE_SPINLOCK(spu_list_lock);

struct cbe_spu_info cbe_spu_info[MAX_NUMNODES];

EXPORT_SYMBOL_GPL(cbe_spu_info);



EXPORT_SYMBOL_GPL(spu_priv1_ops);

/*

 * Protects cbe_spu_info and spu->number.

 */

static DEFINE_SPINLOCK(spu_lock);



/*

 * List of all spus in the system.

 *

 * This list is iterated by callers from irq context and callers that

 * want to sleep.  Thus modifications need to be done with both

 * spu_full_list_lock and spu_full_list_mutex held, while iterating

 * through it requires either of these locks.

 *

 * In addition spu_full_list_lock protects all assignmens to

 * spu->mm.

 */

static LIST_HEAD(spu_full_list);

static DEFINE_SPINLOCK(spu_full_list_lock);

static DEFINE_MUTEX(spu_full_list_mutex);



void spu_invalidate_slbs(struct spu *spu)

{
@@ -66,12 +84,12 @@ void spu_flush_all_slbs(struct mm_struct *mm) 
	struct spu *spu;

	unsigned long flags;



	spin_lock_irqsave(&spu_list_lock, flags);

	spin_lock_irqsave(&spu_full_list_lock, flags);

	list_for_each_entry(spu, &spu_full_list, full_list) {

		if (spu->mm == mm)

			spu_invalidate_slbs(spu);

	}

	spin_unlock_irqrestore(&spu_list_lock, flags);

	spin_unlock_irqrestore(&spu_full_list_lock, flags);

}



/* The hack below stinks... try to do something better one of
@@ -89,9 +107,9 @@ void spu_associate_mm(struct spu *spu, struct mm_struct *mm) 
{

	unsigned long flags;



	spin_lock_irqsave(&spu_list_lock, flags);

	spin_lock_irqsave(&spu_full_list_lock, flags);

	spu->mm = mm;

	spin_unlock_irqrestore(&spu_list_lock, flags);

	spin_unlock_irqrestore(&spu_full_list_lock, flags);

	if (mm)

		mm_needs_global_tlbie(mm);

}
@@ -429,7 +447,7 @@ struct spu *spu_alloc_spu(struct spu *req_spu) 
{

	struct spu *spu, *ret = NULL;



	mutex_lock(&spu_mutex);

	spin_lock(&spu_lock);

	list_for_each_entry(spu, &cbe_spu_info[req_spu->node].free_spus, list) {

		if (spu == req_spu) {

			list_del_init(&spu->list);
@@ -439,7 +457,7 @@ struct spu *spu_alloc_spu(struct spu *req_spu) 
			break;

		}

	}

	mutex_unlock(&spu_mutex);

	spin_unlock(&spu_lock);

	return ret;

}

EXPORT_SYMBOL_GPL(spu_alloc_spu);
@@ -448,14 +466,14 @@ struct spu *spu_alloc_node(int node) 
{

	struct spu *spu = NULL;



	mutex_lock(&spu_mutex);

	spin_lock(&spu_lock);

	if (!list_empty(&cbe_spu_info[node].free_spus)) {

		spu = list_entry(cbe_spu_info[node].free_spus.next, struct spu,

									list);

		list_del_init(&spu->list);

		pr_debug("Got SPU %d %d\n", spu->number, spu->node);

	}

	mutex_unlock(&spu_mutex);

	spin_unlock(&spu_lock);



	if (spu)

		spu_init_channels(spu);
@@ -479,9 +497,9 @@ struct spu *spu_alloc(void) 


void spu_free(struct spu *spu)

{

	mutex_lock(&spu_mutex);

	spin_lock(&spu_lock);

	list_add_tail(&spu->list, &cbe_spu_info[spu->node].free_spus);

	mutex_unlock(&spu_mutex);

	spin_unlock(&spu_lock);

}

EXPORT_SYMBOL_GPL(spu_free);
@@ -502,12 +520,12 @@ struct sysdev_class spu_sysdev_class = { 
int spu_add_sysdev_attr(struct sysdev_attribute *attr)

{

	struct spu *spu;

	mutex_lock(&spu_mutex);



	mutex_lock(&spu_full_list_mutex);

	list_for_each_entry(spu, &spu_full_list, full_list)

		sysdev_create_file(&spu->sysdev, attr);

	mutex_unlock(&spu_full_list_mutex);



	mutex_unlock(&spu_mutex);

	return 0;

}

EXPORT_SYMBOL_GPL(spu_add_sysdev_attr);
@@ -515,12 +533,12 @@ EXPORT_SYMBOL_GPL(spu_add_sysdev_attr); 
int spu_add_sysdev_attr_group(struct attribute_group *attrs)

{

	struct spu *spu;

	mutex_lock(&spu_mutex);



	mutex_lock(&spu_full_list_mutex);

	list_for_each_entry(spu, &spu_full_list, full_list)

		sysfs_create_group(&spu->sysdev.kobj, attrs);

	mutex_unlock(&spu_full_list_mutex);



	mutex_unlock(&spu_mutex);

	return 0;

}

EXPORT_SYMBOL_GPL(spu_add_sysdev_attr_group);
@@ -529,24 +547,22 @@ EXPORT_SYMBOL_GPL(spu_add_sysdev_attr_group); 
void spu_remove_sysdev_attr(struct sysdev_attribute *attr)

{

	struct spu *spu;

	mutex_lock(&spu_mutex);



	mutex_lock(&spu_full_list_mutex);

	list_for_each_entry(spu, &spu_full_list, full_list)

		sysdev_remove_file(&spu->sysdev, attr);



	mutex_unlock(&spu_mutex);

	mutex_unlock(&spu_full_list_mutex);

}

EXPORT_SYMBOL_GPL(spu_remove_sysdev_attr);



void spu_remove_sysdev_attr_group(struct attribute_group *attrs)

{

	struct spu *spu;

	mutex_lock(&spu_mutex);



	mutex_lock(&spu_full_list_mutex);

	list_for_each_entry(spu, &spu_full_list, full_list)

		sysfs_remove_group(&spu->sysdev.kobj, attrs);



	mutex_unlock(&spu_mutex);

	mutex_unlock(&spu_full_list_mutex);

}

EXPORT_SYMBOL_GPL(spu_remove_sysdev_attr_group);
@@ -582,9 +598,9 @@ static int __init create_spu(void *data) 
		goto out;



	spin_lock_init(&spu->register_lock);

	mutex_lock(&spu_mutex);

	spin_lock(&spu_lock);

	spu->number = number++;

	mutex_unlock(&spu_mutex);

	spin_unlock(&spu_lock);



	ret = spu_create_spu(spu, data);
@@ -601,14 +617,17 @@ static int __init create_spu(void *data) 
	if (ret)

		goto out_free_irqs;



	mutex_lock(&spu_mutex);

	spin_lock_irqsave(&spu_list_lock, flags);

	spin_lock(&spu_lock);

	list_add(&spu->list, &cbe_spu_info[spu->node].free_spus);

	list_add(&spu->cbe_list, &cbe_spu_info[spu->node].spus);

	cbe_spu_info[spu->node].n_spus++;

	spin_unlock(&spu_lock);



	mutex_lock(&spu_full_list_mutex);

	spin_lock_irqsave(&spu_full_list_lock, flags);

	list_add(&spu->full_list, &spu_full_list);

	spin_unlock_irqrestore(&spu_list_lock, flags);

	mutex_unlock(&spu_mutex);

	spin_unlock_irqrestore(&spu_full_list_lock, flags);

	mutex_unlock(&spu_full_list_mutex);



	spu->stats.util_state = SPU_UTIL_IDLE_LOADED;

	ktime_get_ts(&ts);
@@ -675,9 +694,6 @@ static ssize_t spu_stat_show(struct sys_device *sysdev, char *buf) 


static SYSDEV_ATTR(stat, 0644, spu_stat_show, NULL);



struct cbe_spu_info cbe_spu_info[MAX_NUMNODES];

EXPORT_SYMBOL_GPL(cbe_spu_info);



/* Hardcoded affinity idxs for QS20 */

#define SPES_PER_BE 8

static int QS20_reg_idxs[SPES_PER_BE] =   { 0, 2, 4, 6, 7, 5, 3, 1 };
@@ -847,8 +863,10 @@ static int __init init_spu_base(void) 
		fb_append_extra_logo(&logo_spe_clut224, ret);

	}



	mutex_lock(&spu_full_list_mutex);

	xmon_register_spus(&spu_full_list);

	crash_register_spus(&spu_full_list);

	mutex_unlock(&spu_full_list_mutex);

	spu_add_sysdev_attr(&attr_stat);



	if (of_has_vicinity()) {