Merge tag 'irq-msi-2025-05-25' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull MSI updates from Thomas Gleixner:
 "Updates for the MSI subsystem (core code and PCI):

   - Switch the MSI descriptor locking to lock guards

   - Replace a broken and naive implementation of PCI/MSI-X control word
     updates in the PCI/TPH driver with a properly serialized variant in
     the PCI/MSI core code.

   - Remove the MSI descriptor abuse in the SCCI/UFS/QCOM driver by
     replacing the direct access to the MSI descriptors with the proper
     API function calls. People will never understand that APIs exist
     for a reason...

   - Provide core infrastructre for the upcoming PCI endpoint library
     extensions. Currently limited to ARM GICv3+, but in theory
     extensible to other architectures.

   - Provide a MSI domain::teardown() callback, which allows drivers to
     undo the effects of the prepare() callback.

   - Move the MSI domain::prepare() callback invocation to domain
     creation time to avoid redundant (and in case of ARM/GIC-V3-ITS
     confusing) invocations on every allocation.

     In combination with the new teardown callback this removes some
     ugly hacks in the GIC-V3-ITS driver, which pretended to work around
     the short comings of the core code so far. With this update the
     code is correct by design and implementation.

   - Make the irqchip MSI library globally available, provide a MSI
     parent domain creation helper and convert a bunch of (PCI/)MSI
     drivers over to the modern MSI parent mechanism. This is the first
     step to get rid of at least one incarnation of the three PCI/MSI
     management schemes.

   - The usual small cleanups and improvements"

* tag 'irq-msi-2025-05-25' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (33 commits)
  PCI/MSI: Use bool for MSI enable state tracking
  PCI: tegra: Convert to MSI parent infrastructure
  PCI: xgene: Convert to MSI parent infrastructure
  PCI: apple: Convert to MSI parent infrastructure
  irqchip/msi-lib: Honour the MSI_FLAG_NO_AFFINITY flag
  irqchip/mvebu: Convert to msi_create_parent_irq_domain() helper
  irqchip/gic: Convert to msi_create_parent_irq_domain() helper
  genirq/msi: Add helper for creating MSI-parent irq domains
  irqchip: Make irq-msi-lib.h globally available
  irqchip/gic-v3-its: Use allocation size from the prepare call
  genirq/msi: Engage the .msi_teardown() callback on domain removal
  genirq/msi: Move prepare() call to per-device allocation
  irqchip/gic-v3-its: Implement .msi_teardown() callback
  genirq/msi: Add .msi_teardown() callback as the reverse of .msi_prepare()
  irqchip/gic-v3-its: Add support for device tree msi-map and msi-mask
  dt-bindings: PCI: pci-ep: Add support for iommu-map and msi-map
  irqchip/gic-v3-its: Set IRQ_DOMAIN_FLAG_MSI_IMMUTABLE for ITS
  irqdomain: Add IRQ_DOMAIN_FLAG_MSI_IMMUTABLE and irq_domain_is_msi_immutable()
  platform-msi: Add msi_remove_device_irq_domain() in platform_device_msi_free_irqs_all()
  genirq/msi: Rename msi_[un]lock_descs()
  ...

5 files changed, 76 insertions, 6 deletions

diff --git a/include/linux/cleanup.h b/include/linux/cleanup.h
index 7e57047e1564..7093e1d08af0 100644
--- a/include/linux/cleanup.h
+++ b/include/linux/cleanup.h
@@ -216,6 +216,25 @@ const volatile void * __must_check_fn(const volatile void *val)
 
 #define return_ptr(p)	return no_free_ptr(p)
 
+/*
+ * Only for situations where an allocation is handed in to another function
+ * and consumed by that function on success.
+ *
+ *	struct foo *f __free(kfree) = kzalloc(sizeof(*f), GFP_KERNEL);
+ *
+ *	setup(f);
+ *	if (some_condition)
+ *		return -EINVAL;
+ *	....
+ *	ret = bar(f);
+ *	if (!ret)
+ *		retain_and_null_ptr(f);
+ *	return ret;
+ *
+ * After retain_and_null_ptr(f) the variable f is NULL and cannot be
+ * dereferenced anymore.
+ */
+#define retain_and_null_ptr(p)		((void)__get_and_null(p, NULL))
 
 /*
  * DEFINE_CLASS(name, type, exit, init, init_args...):
diff --git a/include/linux/irqchip/irq-msi-lib.h b/include/linux/irqchip/irq-msi-lib.h
new file mode 100644
index 000000000000..dd8d1d138544
--- /dev/null
+++ b/include/linux/irqchip/irq-msi-lib.h
@@ -0,0 +1,27 @@
+// SPDX-License-Identifier: GPL-2.0-only
+// Copyright (C) 2022 Linutronix GmbH
+// Copyright (C) 2022 Intel
+
+#ifndef _IRQCHIP_IRQ_MSI_LIB_H
+#define _IRQCHIP_IRQ_MSI_LIB_H
+
+#include <linux/bits.h>
+#include <linux/irqdomain.h>
+#include <linux/msi.h>
+
+#ifdef CONFIG_PCI_MSI
+#define MATCH_PCI_MSI		BIT(DOMAIN_BUS_PCI_MSI)
+#else
+#define MATCH_PCI_MSI		(0)
+#endif
+
+#define MATCH_PLATFORM_MSI	BIT(DOMAIN_BUS_PLATFORM_MSI)
+
+int msi_lib_irq_domain_select(struct irq_domain *d, struct irq_fwspec *fwspec,
+			      enum irq_domain_bus_token bus_token);
+
+bool msi_lib_init_dev_msi_info(struct device *dev, struct irq_domain *domain,
+			       struct irq_domain *real_parent,
+			       struct msi_domain_info *info);
+
+#endif /* _IRQCHIP_IRQ_MSI_LIB_H */
diff --git a/include/linux/irqdomain.h b/include/linux/irqdomain.h
index 2f6e4c9dd743..7387d183029b 100644
--- a/include/linux/irqdomain.h
+++ b/include/linux/irqdomain.h
@@ -209,6 +209,9 @@ enum {
 	/* Irq domain must destroy generic chips when removed */
 	IRQ_DOMAIN_FLAG_DESTROY_GC	= (1 << 10),
 
+	/* Address and data pair is mutable when irq_set_affinity() */
+	IRQ_DOMAIN_FLAG_MSI_IMMUTABLE	= (1 << 11),
+
 	/*
 	 * Flags starting from IRQ_DOMAIN_FLAG_NONCORE are reserved
 	 * for implementation specific purposes and ignored by the
@@ -256,6 +259,8 @@ 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;
 
 /**
@@ -627,6 +632,10 @@ static inline bool irq_domain_is_msi_device(struct irq_domain *domain)
 	return domain->flags & IRQ_DOMAIN_FLAG_MSI_DEVICE;
 }
 
+static inline bool irq_domain_is_msi_immutable(struct irq_domain *domain)
+{
+	return domain->flags & IRQ_DOMAIN_FLAG_MSI_IMMUTABLE;
+}
 #else	/* CONFIG_IRQ_DOMAIN_HIERARCHY */
 static inline int irq_domain_alloc_irqs(struct irq_domain *domain, unsigned int nr_irqs,
 					int node, void *arg)
diff --git a/include/linux/msi.h b/include/linux/msi.h
index 86e42742fd0f..6863540f4b71 100644
--- a/include/linux/msi.h
+++ b/include/linux/msi.h
@@ -229,8 +229,11 @@ struct msi_dev_domain {
 
 int msi_setup_device_data(struct device *dev);
 
-void msi_lock_descs(struct device *dev);
-void msi_unlock_descs(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);
@@ -420,6 +423,7 @@ struct msi_domain_info;
  * @msi_init:		Domain specific init function for MSI interrupts
  * @msi_free:		Domain specific function to free a MSI interrupts
  * @msi_prepare:	Prepare the allocation of the interrupts in the domain
+ * @msi_teardown:	Reverse the effects of @msi_prepare
  * @prepare_desc:	Optional function to prepare the allocated MSI descriptor
  *			in the domain
  * @set_desc:		Set the msi descriptor for an interrupt
@@ -435,8 +439,9 @@ struct msi_domain_info;
  * @get_hwirq, @msi_init and @msi_free are callbacks used by the underlying
  * irqdomain.
  *
- * @msi_check, @msi_prepare, @prepare_desc and @set_desc are callbacks used by the
- * msi_domain_alloc/free_irqs*() variants.
+ * @msi_check, @msi_prepare, @msi_teardown, @prepare_desc and
+ * @set_desc are callbacks used by the msi_domain_alloc/free_irqs*()
+ * variants.
  *
  * @domain_alloc_irqs, @domain_free_irqs can be used to override the
  * default allocation/free functions (__msi_domain_alloc/free_irqs). This
@@ -458,6 +463,8 @@ struct msi_domain_ops {
 	int		(*msi_prepare)(struct irq_domain *domain,
 				       struct device *dev, int nvec,
 				       msi_alloc_info_t *arg);
+	void		(*msi_teardown)(struct irq_domain *domain,
+					msi_alloc_info_t *arg);
 	void		(*prepare_desc)(struct irq_domain *domain, msi_alloc_info_t *arg,
 					struct msi_desc *desc);
 	void		(*set_desc)(msi_alloc_info_t *arg,
@@ -486,6 +493,7 @@ struct msi_domain_ops {
  * @handler:		Optional: associated interrupt flow handler
  * @handler_data:	Optional: associated interrupt flow handler data
  * @handler_name:	Optional: associated interrupt flow handler name
+ * @alloc_data:		Optional: associated interrupt allocation data
  * @data:		Optional: domain specific data
  */
 struct msi_domain_info {
@@ -498,6 +506,7 @@ struct msi_domain_info {
 	irq_flow_handler_t		handler;
 	void				*handler_data;
 	const char			*handler_name;
+	msi_alloc_info_t		*alloc_data;
 	void				*data;
 };
 
@@ -507,12 +516,14 @@ struct msi_domain_info {
  * @chip:	Interrupt chip for this domain
  * @ops:	MSI domain ops
  * @info:	MSI domain info data
+ * @alloc_info:	MSI domain allocation data (architecture specific)
  */
 struct msi_domain_template {
 	char			name[48];
 	struct irq_chip		chip;
 	struct msi_domain_ops	ops;
 	struct msi_domain_info	info;
+	msi_alloc_info_t	alloc_info;
 };
 
 /*
@@ -625,6 +636,10 @@ struct irq_domain *msi_create_irq_domain(struct fwnode_handle *fwnode,
 					 struct msi_domain_info *info,
 					 struct irq_domain *parent);
 
+struct irq_domain_info;
+struct irq_domain *msi_create_parent_irq_domain(struct irq_domain_info *info,
+						const struct msi_parent_ops *msi_parent_ops);
+
 bool msi_create_device_irq_domain(struct device *dev, unsigned int domid,
 				  const struct msi_domain_template *template,
 				  unsigned int hwsize, void *domain_data,
diff --git a/include/linux/pci.h b/include/linux/pci.h
index 51e2bd6405cd..b231cbc67a35 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -1671,7 +1671,7 @@ void pci_disable_msi(struct pci_dev *dev);
 int pci_msix_vec_count(struct pci_dev *dev);
 void pci_disable_msix(struct pci_dev *dev);
 void pci_restore_msi_state(struct pci_dev *dev);
-int pci_msi_enabled(void);
+bool pci_msi_enabled(void);
 int pci_enable_msi(struct pci_dev *dev);
 int pci_enable_msix_range(struct pci_dev *dev, struct msix_entry *entries,
 			  int minvec, int maxvec);
@@ -1704,7 +1704,7 @@ static inline void pci_disable_msi(struct pci_dev *dev) { }
 static inline int pci_msix_vec_count(struct pci_dev *dev) { return -ENOSYS; }
 static inline void pci_disable_msix(struct pci_dev *dev) { }
 static inline void pci_restore_msi_state(struct pci_dev *dev) { }
-static inline int pci_msi_enabled(void) { return 0; }
+static inline bool pci_msi_enabled(void) { return false; }
 static inline int pci_enable_msi(struct pci_dev *dev)
 { return -ENOSYS; }
 static inline int pci_enable_msix_range(struct pci_dev *dev,