Commit 5c99e022 authored by Thomas Gleixner's avatar Thomas Gleixner
Browse files

genirq/msi: Use lock guards for MSI descriptor locking 



Provide a lock guard for MSI descriptor locking and update the core code
accordingly.

No functional change intended.

Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
Reviewed-by: default avatarJonathan Cameron <Jonathan.Cameron@huawei.com>
Link: https://lore.kernel.org/all/20250313130321.506045185@linutronix.de
parent 08549ff3

include/linux/irqdomain.h

+2 −0
Original line number Diff line number Diff line
@@ -281,6 +281,8 @@ static inline struct fwnode_handle *irq_domain_alloc_fwnode(phys_addr_t *pa) 


void irq_domain_free_fwnode(struct fwnode_handle *fwnode);



DEFINE_FREE(irq_domain_free_fwnode, struct fwnode_handle *, if (_T) irq_domain_free_fwnode(_T))



struct irq_domain_chip_generic_info;



/**

include/linux/msi.h

+3 −0
Original line number Diff line number Diff line
@@ -227,6 +227,9 @@ int msi_setup_device_data(struct device *dev); 
void msi_lock_descs(struct device *dev);

void msi_unlock_descs(struct device *dev);



DEFINE_LOCK_GUARD_1(msi_descs_lock, struct device, msi_lock_descs(_T->lock),

		    msi_unlock_descs(_T->lock));



struct msi_desc *msi_domain_first_desc(struct device *dev, unsigned int domid,

				       enum msi_desc_filter filter);

kernel/irq/msi.c

+40 −69
Original line number Diff line number Diff line
@@ -443,7 +443,6 @@ EXPORT_SYMBOL_GPL(msi_next_desc); 
unsigned int msi_domain_get_virq(struct device *dev, unsigned int domid, unsigned int index)

{

	struct msi_desc *desc;

	unsigned int ret = 0;

	bool pcimsi = false;

	struct xarray *xa;
@@ -457,7 +456,7 @@ unsigned int msi_domain_get_virq(struct device *dev, unsigned int domid, unsigne 
	if (dev_is_pci(dev) && domid == MSI_DEFAULT_DOMAIN)

		pcimsi = to_pci_dev(dev)->msi_enabled;



	msi_lock_descs(dev);

	guard(msi_descs_lock)(dev);

	xa = &dev->msi.data->__domains[domid].store;

	desc = xa_load(xa, pcimsi ? 0 : index);

	if (desc && desc->irq) {
@@ -466,16 +465,12 @@ unsigned int msi_domain_get_virq(struct device *dev, unsigned int domid, unsigne 
		 * PCI-MSIX and platform MSI use a descriptor per

		 * interrupt.

		 */

		if (pcimsi) {

		if (!pcimsi)

			return desc->irq;

		if (index < desc->nvec_used)

				ret = desc->irq + index;

		} else {

			ret = desc->irq;

		}

			return desc->irq + index;

	}



	msi_unlock_descs(dev);

	return ret;

	return 0;

}

EXPORT_SYMBOL_GPL(msi_domain_get_virq);
@@ -993,9 +988,8 @@ bool msi_create_device_irq_domain(struct device *dev, unsigned int domid, 
				  void *chip_data)

{

	struct irq_domain *domain, *parent = dev->msi.domain;

	struct fwnode_handle *fwnode, *fwnalloced = NULL;

	struct msi_domain_template *bundle;

	const struct msi_parent_ops *pops;

	struct fwnode_handle *fwnode;



	if (!irq_domain_is_msi_parent(parent))

		return false;
@@ -1003,6 +997,7 @@ bool msi_create_device_irq_domain(struct device *dev, unsigned int domid, 
	if (domid >= MSI_MAX_DEVICE_IRQDOMAINS)

		return false;



	struct msi_domain_template *bundle __free(kfree) =

		bundle = kmemdup(template, sizeof(*bundle), GFP_KERNEL);

	if (!bundle)

		return false;
@@ -1026,41 +1021,36 @@ bool msi_create_device_irq_domain(struct device *dev, unsigned int domid, 
	 * node as they are not guaranteed to have a fwnode. They are never

	 * looked up and always handled in the context of the device.

	 */

	if (bundle->info.flags & MSI_FLAG_USE_DEV_FWNODE)

		fwnode = dev->fwnode;

	struct fwnode_handle *fwnode_alloced __free(irq_domain_free_fwnode) = NULL;



	if (!(bundle->info.flags & MSI_FLAG_USE_DEV_FWNODE))

		fwnode = fwnode_alloced = irq_domain_alloc_named_fwnode(bundle->name);

	else

		fwnode = fwnalloced = irq_domain_alloc_named_fwnode(bundle->name);

		fwnode = dev->fwnode;



	if (!fwnode)

		goto free_bundle;

		return false;



	if (msi_setup_device_data(dev))

		goto free_fwnode;



	msi_lock_descs(dev);

		return false;



	guard(msi_descs_lock)(dev);

	if (WARN_ON_ONCE(msi_get_device_domain(dev, domid)))

		goto fail;

		return false;



	if (!pops->init_dev_msi_info(dev, parent, parent, &bundle->info))

		goto fail;

		return false;



	domain = __msi_create_irq_domain(fwnode, &bundle->info, IRQ_DOMAIN_FLAG_MSI_DEVICE, parent);

	if (!domain)

		goto fail;

		return false;



	/* @bundle and @fwnode_alloced are now in use. Prevent cleanup */

	retain_ptr(bundle);

	retain_ptr(fwnode_alloced);

	domain->dev = dev;

	dev->msi.data->__domains[domid].domain = domain;

	msi_unlock_descs(dev);

	return true;



fail:

	msi_unlock_descs(dev);

free_fwnode:

	irq_domain_free_fwnode(fwnalloced);

free_bundle:

	kfree(bundle);

	return false;

}



/**
@@ -1074,12 +1064,10 @@ void msi_remove_device_irq_domain(struct device *dev, unsigned int domid) 
	struct msi_domain_info *info;

	struct irq_domain *domain;



	msi_lock_descs(dev);



	guard(msi_descs_lock)(dev);

	domain = msi_get_device_domain(dev, domid);



	if (!domain || !irq_domain_is_msi_device(domain))

		goto unlock;

		return;



	dev->msi.data->__domains[domid].domain = NULL;

	info = domain->host_data;
@@ -1088,9 +1076,6 @@ void msi_remove_device_irq_domain(struct device *dev, unsigned int domid) 
	irq_domain_remove(domain);

	irq_domain_free_fwnode(fwnode);

	kfree(container_of(info, struct msi_domain_template, info));



unlock:

	msi_unlock_descs(dev);

}



/**
@@ -1106,16 +1091,14 @@ bool msi_match_device_irq_domain(struct device *dev, unsigned int domid, 
{

	struct msi_domain_info *info;

	struct irq_domain *domain;

	bool ret = false;



	msi_lock_descs(dev);

	guard(msi_descs_lock)(dev);

	domain = msi_get_device_domain(dev, domid);

	if (domain && irq_domain_is_msi_device(domain)) {

		info = domain->host_data;

		ret = info->bus_token == bus_token;

		return info->bus_token == bus_token;

	}

	msi_unlock_descs(dev);

	return ret;

	return false;

}



static int msi_domain_prepare_irqs(struct irq_domain *domain, struct device *dev,
@@ -1365,12 +1348,9 @@ int msi_domain_alloc_irqs_range(struct device *dev, unsigned int domid, 
		.last	= last,

		.nirqs	= last + 1 - first,

	};

	int ret;



	msi_lock_descs(dev);

	ret = msi_domain_alloc_locked(dev, &ctrl);

	msi_unlock_descs(dev);

	return ret;

	guard(msi_descs_lock)(dev);

	return msi_domain_alloc_locked(dev, &ctrl);

}

EXPORT_SYMBOL_GPL(msi_domain_alloc_irqs_range);
@@ -1474,12 +1454,8 @@ struct msi_map msi_domain_alloc_irq_at(struct device *dev, unsigned int domid, u 
				       const struct irq_affinity_desc *affdesc,

				       union msi_instance_cookie *icookie)

{

	struct msi_map map;



	msi_lock_descs(dev);

	map = __msi_domain_alloc_irq_at(dev, domid, index, affdesc, icookie);

	msi_unlock_descs(dev);

	return map;

	guard(msi_descs_lock)(dev);

	return __msi_domain_alloc_irq_at(dev, domid, index, affdesc, icookie);

}



/**
@@ -1516,13 +1492,11 @@ int msi_device_domain_alloc_wired(struct irq_domain *domain, unsigned int hwirq, 


	icookie.value = ((u64)type << 32) | hwirq;



	msi_lock_descs(dev);

	guard(msi_descs_lock)(dev);

	if (WARN_ON_ONCE(msi_get_device_domain(dev, domid) != domain))

		map.index = -EINVAL;

	else

		map = __msi_domain_alloc_irq_at(dev, domid, MSI_ANY_INDEX, NULL, &icookie);

	msi_unlock_descs(dev);



	return map.index >= 0 ? map.virq : map.index;

}
@@ -1615,9 +1589,8 @@ static void msi_domain_free_irqs_range_locked(struct device *dev, unsigned int d 
void msi_domain_free_irqs_range(struct device *dev, unsigned int domid,

				unsigned int first, unsigned int last)

{

	msi_lock_descs(dev);

	guard(msi_descs_lock)(dev);

	msi_domain_free_irqs_range_locked(dev, domid, first, last);

	msi_unlock_descs(dev);

}

EXPORT_SYMBOL_GPL(msi_domain_free_irqs_all);
@@ -1647,9 +1620,8 @@ void msi_domain_free_irqs_all_locked(struct device *dev, unsigned int domid) 
 */

void msi_domain_free_irqs_all(struct device *dev, unsigned int domid)

{

	msi_lock_descs(dev);

	guard(msi_descs_lock)(dev);

	msi_domain_free_irqs_all_locked(dev, domid);

	msi_unlock_descs(dev);

}



/**
@@ -1668,13 +1640,12 @@ void msi_device_domain_free_wired(struct irq_domain *domain, unsigned int virq) 
	if (WARN_ON_ONCE(!dev || !desc || domain->bus_token != DOMAIN_BUS_WIRED_TO_MSI))

		return;



	msi_lock_descs(dev);

	if (!WARN_ON_ONCE(msi_get_device_domain(dev, MSI_DEFAULT_DOMAIN) != domain)) {

	guard(msi_descs_lock)(dev);

	if (WARN_ON_ONCE(msi_get_device_domain(dev, MSI_DEFAULT_DOMAIN) != domain))

		return;

	msi_domain_free_irqs_range_locked(dev, MSI_DEFAULT_DOMAIN, desc->msi_index,

					  desc->msi_index);

}

	msi_unlock_descs(dev);

}



/**

 * msi_get_domain_info - Get the MSI interrupt domain info for @domain