Merge tag 'irq-msi-2025-03-23' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull MSI irq updates from Thomas Gleixner: - Switch the MSI descriptor locking to guards - Replace the broken PCI/TPH implementation, which lacks any form of serialization against concurrent modifications with a properly serialized mechanism in the PCI/MSI core code - Replace the MSI descriptor abuse in the SCSI/UFS Qualcom driver with dedicated driver internal storage * tag 'irq-msi-2025-03-23' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: genirq/msi: Rename msi_[un]lock_descs() scsi: ufs: qcom: Remove the MSI descriptor abuse PCI/TPH: Replace the broken MSI-X control word update PCI/MSI: Provide a sane mechanism for TPH PCI: hv: Switch MSI descriptor locking to guard() PCI/MSI: Switch to MSI descriptor locking to guard() NTB/msi: Switch MSI descriptor locking to lock guard() soc: ti: ti_sci_inta_msi: Switch MSI descriptor locking to guard() genirq/msi: Use lock guards for MSI descriptor locking cleanup: Provide retain_ptr() genirq/msi: Make a few functions static
2026-05-12 16:15:05 -04:00 · 2025-03-25 09:15:17 -07:00
parent 43a7eec035 8327df4059
commit 36f5f026df
12 changed files with 256 additions and 291 deletions
--- a/kernel/irq/msi.c
+++ b/kernel/irq/msi.c
@@ -270,16 +270,11 @@ static int msi_domain_add_simple_msi_descs(struct device *dev, struct msi_ctrl *
 	return ret;
 }

-void __get_cached_msi_msg(struct msi_desc *entry, struct msi_msg *msg)
-{
-	*msg = entry->msg;
-}
-
 void get_cached_msi_msg(unsigned int irq, struct msi_msg *msg)
 {
 	struct msi_desc *entry = irq_get_msi_desc(irq);

-	__get_cached_msi_msg(entry, msg);
+	*msg = entry->msg;
 }
 EXPORT_SYMBOL_GPL(get_cached_msi_msg);

@@ -343,26 +338,30 @@ int msi_setup_device_data(struct device *dev)
 }

 /**
- * msi_lock_descs - Lock the MSI descriptor storage of a device
+ * __msi_lock_descs - Lock the MSI descriptor storage of a device
 * @dev:	Device to operate on
+ *
+ * Internal function for guard(msi_descs_lock). Don't use in code.
 */
-void msi_lock_descs(struct device *dev)
+void __msi_lock_descs(struct device *dev)
 {
 	mutex_lock(&dev->msi.data->mutex);
 }
-EXPORT_SYMBOL_GPL(msi_lock_descs);
+EXPORT_SYMBOL_GPL(__msi_lock_descs);

 /**
- * msi_unlock_descs - Unlock the MSI descriptor storage of a device
+ * __msi_unlock_descs - Unlock the MSI descriptor storage of a device
 * @dev:	Device to operate on
+ *
+ * Internal function for guard(msi_descs_lock). Don't use in code.
 */
-void msi_unlock_descs(struct device *dev)
+void __msi_unlock_descs(struct device *dev)
 {
 	/* Invalidate the index which was cached by the iterator */
 	dev->msi.data->__iter_idx = MSI_XA_MAX_INDEX;
 	mutex_unlock(&dev->msi.data->mutex);
 }
-EXPORT_SYMBOL_GPL(msi_unlock_descs);
+EXPORT_SYMBOL_GPL(__msi_unlock_descs);

 static struct msi_desc *msi_find_desc(struct msi_device_data *md, unsigned int domid,
 				      enum msi_desc_filter filter)
@@ -448,7 +447,6 @@ 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;

@@ -462,7 +460,7 @@ 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) {
@@ -471,16 +469,12 @@ 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 (index < desc->nvec_used)
-				ret = desc->irq + index;
-		} else {
-			ret = desc->irq;
-		}
+		if (!pcimsi)
+			return desc->irq;
+		if (index < desc->nvec_used)
+			return desc->irq + index;
 	}
-
-	msi_unlock_descs(dev);
-	return ret;
+	return 0;
 }
 EXPORT_SYMBOL_GPL(msi_domain_get_virq);

@@ -998,9 +992,8 @@ 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;
@@ -1008,7 +1001,8 @@ bool msi_create_device_irq_domain(struct device *dev, unsigned int domid,
 	if (domid >= MSI_MAX_DEVICE_IRQDOMAINS)
 		return false;

-	bundle = kmemdup(template, sizeof(*bundle), GFP_KERNEL);
+	struct msi_domain_template *bundle __free(kfree) =
+		bundle = kmemdup(template, sizeof(*bundle), GFP_KERNEL);
 	if (!bundle)
 		return false;

@@ -1031,41 +1025,36 @@ 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;
 }

 /**
@@ -1079,12 +1068,10 @@ 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;
@@ -1093,9 +1080,6 @@ 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);
 }

 /**
@@ -1111,16 +1095,14 @@ 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,
@@ -1351,33 +1333,6 @@ static int msi_domain_alloc_locked(struct device *dev, struct msi_ctrl *ctrl)
 	return ret;
 }

-/**
- * msi_domain_alloc_irqs_range_locked - Allocate interrupts from a MSI interrupt domain
- * @dev:	Pointer to device struct of the device for which the interrupts
- *		are allocated
- * @domid:	Id of the interrupt domain to operate on
- * @first:	First index to allocate (inclusive)
- * @last:	Last index to allocate (inclusive)
- *
- * Must be invoked from within a msi_lock_descs() / msi_unlock_descs()
- * pair. Use this for MSI irqdomains which implement their own descriptor
- * allocation/free.
- *
- * Return: %0 on success or an error code.
- */
-int msi_domain_alloc_irqs_range_locked(struct device *dev, unsigned int domid,
-				       unsigned int first, unsigned int last)
-{
-	struct msi_ctrl ctrl = {
-		.domid	= domid,
-		.first	= first,
-		.last	= last,
-		.nirqs	= last + 1 - first,
-	};
-
-	return msi_domain_alloc_locked(dev, &ctrl);
-}
-
 /**
 * msi_domain_alloc_irqs_range - Allocate interrupts from a MSI interrupt domain
 * @dev:	Pointer to device struct of the device for which the interrupts
@@ -1391,12 +1346,15 @@ int msi_domain_alloc_irqs_range_locked(struct device *dev, unsigned int domid,
 int msi_domain_alloc_irqs_range(struct device *dev, unsigned int domid,
 				unsigned int first, unsigned int last)
 {
-	int ret;
+	struct msi_ctrl ctrl = {
+		.domid	= domid,
+		.first	= first,
+		.last	= last,
+		.nirqs	= last + 1 - first,
+	};

-	msi_lock_descs(dev);
-	ret = msi_domain_alloc_irqs_range_locked(dev, domid, first, last);
-	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);

@@ -1500,12 +1458,8 @@ 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);
 }

 /**
@@ -1542,13 +1496,11 @@ 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;
 }

@@ -1618,8 +1570,8 @@ static void msi_domain_free_locked(struct device *dev, struct msi_ctrl *ctrl)
 * @first:	First index to free (inclusive)
 * @last:	Last index to free (inclusive)
 */
-void msi_domain_free_irqs_range_locked(struct device *dev, unsigned int domid,
-				       unsigned int first, unsigned int last)
+static void msi_domain_free_irqs_range_locked(struct device *dev, unsigned int domid,
+					      unsigned int first, unsigned int last)
 {
 	struct msi_ctrl ctrl = {
 		.domid	= domid,
@@ -1641,9 +1593,8 @@ void msi_domain_free_irqs_range_locked(struct device *dev, unsigned int domid,
 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);

@@ -1673,9 +1624,8 @@ 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);
 }

 /**
@@ -1694,12 +1644,11 @@ 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)) {
-		msi_domain_free_irqs_range_locked(dev, MSI_DEFAULT_DOMAIN, desc->msi_index,
-						  desc->msi_index);
-	}
-	msi_unlock_descs(dev);
+	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);
 }

 /**