Commit 3d3248db authored by Kishon Vijay Abraham I's avatar Kishon Vijay Abraham I Committed by Lorenzo Pieralisi
Browse files

PCI: endpoint: Replace spinlock with mutex 



The pci_epc_ops is not intended to be invoked from interrupt context.
Hence replace spin_lock_irqsave and spin_unlock_irqrestore with
mutex_lock and mutex_unlock respectively.

Signed-off-by: default avatarKishon Vijay Abraham I <kishon@ti.com>
Signed-off-by: default avatarLorenzo Pieralisi <lorenzo.pieralisi@arm.com>
parent 5779dd0a

drivers/pci/endpoint/pci-epc-core.c

+31 −51
Original line number Diff line number Diff line
@@ -120,7 +120,6 @@ const struct pci_epc_features *pci_epc_get_features(struct pci_epc *epc, 
						    u8 func_no)

{

	const struct pci_epc_features *epc_features;

	unsigned long flags;



	if (IS_ERR_OR_NULL(epc) || func_no >= epc->max_functions)

		return NULL;
@@ -128,9 +127,9 @@ const struct pci_epc_features *pci_epc_get_features(struct pci_epc *epc, 
	if (!epc->ops->get_features)

		return NULL;



	spin_lock_irqsave(&epc->lock, flags);

	mutex_lock(&epc->lock);

	epc_features = epc->ops->get_features(epc, func_no);

	spin_unlock_irqrestore(&epc->lock, flags);

	mutex_unlock(&epc->lock);



	return epc_features;

}
@@ -144,14 +143,12 @@ EXPORT_SYMBOL_GPL(pci_epc_get_features); 
 */

void pci_epc_stop(struct pci_epc *epc)

{

	unsigned long flags;



	if (IS_ERR(epc) || !epc->ops->stop)

		return;



	spin_lock_irqsave(&epc->lock, flags);

	mutex_lock(&epc->lock);

	epc->ops->stop(epc);

	spin_unlock_irqrestore(&epc->lock, flags);

	mutex_unlock(&epc->lock);

}

EXPORT_SYMBOL_GPL(pci_epc_stop);
@@ -164,7 +161,6 @@ EXPORT_SYMBOL_GPL(pci_epc_stop); 
int pci_epc_start(struct pci_epc *epc)

{

	int ret;

	unsigned long flags;



	if (IS_ERR(epc))

		return -EINVAL;
@@ -172,9 +168,9 @@ int pci_epc_start(struct pci_epc *epc) 
	if (!epc->ops->start)

		return 0;



	spin_lock_irqsave(&epc->lock, flags);

	mutex_lock(&epc->lock);

	ret = epc->ops->start(epc);

	spin_unlock_irqrestore(&epc->lock, flags);

	mutex_unlock(&epc->lock);



	return ret;

}
@@ -193,7 +189,6 @@ int pci_epc_raise_irq(struct pci_epc *epc, u8 func_no, 
		      enum pci_epc_irq_type type, u16 interrupt_num)

{

	int ret;

	unsigned long flags;



	if (IS_ERR_OR_NULL(epc) || func_no >= epc->max_functions)

		return -EINVAL;
@@ -201,9 +196,9 @@ int pci_epc_raise_irq(struct pci_epc *epc, u8 func_no, 
	if (!epc->ops->raise_irq)

		return 0;



	spin_lock_irqsave(&epc->lock, flags);

	mutex_lock(&epc->lock);

	ret = epc->ops->raise_irq(epc, func_no, type, interrupt_num);

	spin_unlock_irqrestore(&epc->lock, flags);

	mutex_unlock(&epc->lock);



	return ret;

}
@@ -219,7 +214,6 @@ EXPORT_SYMBOL_GPL(pci_epc_raise_irq); 
int pci_epc_get_msi(struct pci_epc *epc, u8 func_no)

{

	int interrupt;

	unsigned long flags;



	if (IS_ERR_OR_NULL(epc) || func_no >= epc->max_functions)

		return 0;
@@ -227,9 +221,9 @@ int pci_epc_get_msi(struct pci_epc *epc, u8 func_no) 
	if (!epc->ops->get_msi)

		return 0;



	spin_lock_irqsave(&epc->lock, flags);

	mutex_lock(&epc->lock);

	interrupt = epc->ops->get_msi(epc, func_no);

	spin_unlock_irqrestore(&epc->lock, flags);

	mutex_unlock(&epc->lock);



	if (interrupt < 0)

		return 0;
@@ -252,7 +246,6 @@ int pci_epc_set_msi(struct pci_epc *epc, u8 func_no, u8 interrupts) 
{

	int ret;

	u8 encode_int;

	unsigned long flags;



	if (IS_ERR_OR_NULL(epc) || func_no >= epc->max_functions ||

	    interrupts > 32)
@@ -263,9 +256,9 @@ int pci_epc_set_msi(struct pci_epc *epc, u8 func_no, u8 interrupts) 


	encode_int = order_base_2(interrupts);



	spin_lock_irqsave(&epc->lock, flags);

	mutex_lock(&epc->lock);

	ret = epc->ops->set_msi(epc, func_no, encode_int);

	spin_unlock_irqrestore(&epc->lock, flags);

	mutex_unlock(&epc->lock);



	return ret;

}
@@ -281,7 +274,6 @@ EXPORT_SYMBOL_GPL(pci_epc_set_msi); 
int pci_epc_get_msix(struct pci_epc *epc, u8 func_no)

{

	int interrupt;

	unsigned long flags;



	if (IS_ERR_OR_NULL(epc) || func_no >= epc->max_functions)

		return 0;
@@ -289,9 +281,9 @@ int pci_epc_get_msix(struct pci_epc *epc, u8 func_no) 
	if (!epc->ops->get_msix)

		return 0;



	spin_lock_irqsave(&epc->lock, flags);

	mutex_lock(&epc->lock);

	interrupt = epc->ops->get_msix(epc, func_no);

	spin_unlock_irqrestore(&epc->lock, flags);

	mutex_unlock(&epc->lock);



	if (interrupt < 0)

		return 0;
@@ -311,7 +303,6 @@ EXPORT_SYMBOL_GPL(pci_epc_get_msix); 
int pci_epc_set_msix(struct pci_epc *epc, u8 func_no, u16 interrupts)

{

	int ret;

	unsigned long flags;



	if (IS_ERR_OR_NULL(epc) || func_no >= epc->max_functions ||

	    interrupts < 1 || interrupts > 2048)
@@ -320,9 +311,9 @@ int pci_epc_set_msix(struct pci_epc *epc, u8 func_no, u16 interrupts) 
	if (!epc->ops->set_msix)

		return 0;



	spin_lock_irqsave(&epc->lock, flags);

	mutex_lock(&epc->lock);

	ret = epc->ops->set_msix(epc, func_no, interrupts - 1);

	spin_unlock_irqrestore(&epc->lock, flags);

	mutex_unlock(&epc->lock);



	return ret;

}
@@ -339,17 +330,15 @@ EXPORT_SYMBOL_GPL(pci_epc_set_msix); 
void pci_epc_unmap_addr(struct pci_epc *epc, u8 func_no,

			phys_addr_t phys_addr)

{

	unsigned long flags;



	if (IS_ERR_OR_NULL(epc) || func_no >= epc->max_functions)

		return;



	if (!epc->ops->unmap_addr)

		return;



	spin_lock_irqsave(&epc->lock, flags);

	mutex_lock(&epc->lock);

	epc->ops->unmap_addr(epc, func_no, phys_addr);

	spin_unlock_irqrestore(&epc->lock, flags);

	mutex_unlock(&epc->lock);

}

EXPORT_SYMBOL_GPL(pci_epc_unmap_addr);
@@ -367,7 +356,6 @@ int pci_epc_map_addr(struct pci_epc *epc, u8 func_no, 
		     phys_addr_t phys_addr, u64 pci_addr, size_t size)

{

	int ret;

	unsigned long flags;



	if (IS_ERR_OR_NULL(epc) || func_no >= epc->max_functions)

		return -EINVAL;
@@ -375,9 +363,9 @@ int pci_epc_map_addr(struct pci_epc *epc, u8 func_no, 
	if (!epc->ops->map_addr)

		return 0;



	spin_lock_irqsave(&epc->lock, flags);

	mutex_lock(&epc->lock);

	ret = epc->ops->map_addr(epc, func_no, phys_addr, pci_addr, size);

	spin_unlock_irqrestore(&epc->lock, flags);

	mutex_unlock(&epc->lock);



	return ret;

}
@@ -394,8 +382,6 @@ EXPORT_SYMBOL_GPL(pci_epc_map_addr); 
void pci_epc_clear_bar(struct pci_epc *epc, u8 func_no,

		       struct pci_epf_bar *epf_bar)

{

	unsigned long flags;



	if (IS_ERR_OR_NULL(epc) || func_no >= epc->max_functions ||

	    (epf_bar->barno == BAR_5 &&

	     epf_bar->flags & PCI_BASE_ADDRESS_MEM_TYPE_64))
@@ -404,9 +390,9 @@ void pci_epc_clear_bar(struct pci_epc *epc, u8 func_no, 
	if (!epc->ops->clear_bar)

		return;



	spin_lock_irqsave(&epc->lock, flags);

	mutex_lock(&epc->lock);

	epc->ops->clear_bar(epc, func_no, epf_bar);

	spin_unlock_irqrestore(&epc->lock, flags);

	mutex_unlock(&epc->lock);

}

EXPORT_SYMBOL_GPL(pci_epc_clear_bar);
@@ -422,7 +408,6 @@ int pci_epc_set_bar(struct pci_epc *epc, u8 func_no, 
		    struct pci_epf_bar *epf_bar)

{

	int ret;

	unsigned long irq_flags;

	int flags = epf_bar->flags;



	if (IS_ERR_OR_NULL(epc) || func_no >= epc->max_functions ||
@@ -437,9 +422,9 @@ int pci_epc_set_bar(struct pci_epc *epc, u8 func_no, 
	if (!epc->ops->set_bar)

		return 0;



	spin_lock_irqsave(&epc->lock, irq_flags);

	mutex_lock(&epc->lock);

	ret = epc->ops->set_bar(epc, func_no, epf_bar);

	spin_unlock_irqrestore(&epc->lock, irq_flags);

	mutex_unlock(&epc->lock);



	return ret;

}
@@ -460,7 +445,6 @@ int pci_epc_write_header(struct pci_epc *epc, u8 func_no, 
			 struct pci_epf_header *header)

{

	int ret;

	unsigned long flags;



	if (IS_ERR_OR_NULL(epc) || func_no >= epc->max_functions)

		return -EINVAL;
@@ -468,9 +452,9 @@ int pci_epc_write_header(struct pci_epc *epc, u8 func_no, 
	if (!epc->ops->write_header)

		return 0;



	spin_lock_irqsave(&epc->lock, flags);

	mutex_lock(&epc->lock);

	ret = epc->ops->write_header(epc, func_no, header);

	spin_unlock_irqrestore(&epc->lock, flags);

	mutex_unlock(&epc->lock);



	return ret;

}
@@ -487,8 +471,6 @@ EXPORT_SYMBOL_GPL(pci_epc_write_header); 
 */

int pci_epc_add_epf(struct pci_epc *epc, struct pci_epf *epf)

{

	unsigned long flags;



	if (epf->epc)

		return -EBUSY;
@@ -500,9 +482,9 @@ int pci_epc_add_epf(struct pci_epc *epc, struct pci_epf *epf) 


	epf->epc = epc;



	spin_lock_irqsave(&epc->lock, flags);

	mutex_lock(&epc->lock);

	list_add_tail(&epf->list, &epc->pci_epf);

	spin_unlock_irqrestore(&epc->lock, flags);

	mutex_unlock(&epc->lock);



	return 0;

}
@@ -517,15 +499,13 @@ EXPORT_SYMBOL_GPL(pci_epc_add_epf); 
 */

void pci_epc_remove_epf(struct pci_epc *epc, struct pci_epf *epf)

{

	unsigned long flags;



	if (!epc || IS_ERR(epc) || !epf)

		return;



	spin_lock_irqsave(&epc->lock, flags);

	mutex_lock(&epc->lock);

	list_del(&epf->list);

	epf->epc = NULL;

	spin_unlock_irqrestore(&epc->lock, flags);

	mutex_unlock(&epc->lock);

}

EXPORT_SYMBOL_GPL(pci_epc_remove_epf);
@@ -604,7 +584,7 @@ __pci_epc_create(struct device *dev, const struct pci_epc_ops *ops, 
		goto err_ret;

	}



	spin_lock_init(&epc->lock);

	mutex_init(&epc->lock);

	INIT_LIST_HEAD(&epc->pci_epf);

	ATOMIC_INIT_NOTIFIER_HEAD(&epc->notifier);

include/linux/pci-epc.h

+3 −3
Original line number Diff line number Diff line
@@ -88,7 +88,7 @@ struct pci_epc_mem { 
 * @mem: address space of the endpoint controller

 * @max_functions: max number of functions that can be configured in this EPC

 * @group: configfs group representing the PCI EPC device

 * @lock: spinlock to protect pci_epc ops

 * @lock: mutex to protect pci_epc ops

 * @notifier: used to notify EPF of any EPC events (like linkup)

 */

struct pci_epc {
@@ -98,8 +98,8 @@ struct pci_epc { 
	struct pci_epc_mem		*mem;

	u8				max_functions;

	struct config_group		*group;

	/* spinlock to protect against concurrent access of EP controller */

	spinlock_t			lock;

	/* mutex to protect against concurrent access of EP controller */

	struct mutex			lock;

	struct atomic_notifier_head	notifier;

};