[PATCH v2 0/6] fsl-mc: Move over to device MSI infrastructure

[PATCH v2 0/6] fsl-mc: Move over to device MSI infrastructure

[Marc Zyngier]

This is the second drop of this cleanup series for the fsl-mc MSI
infrastructure, initially posted at [1].

* From v1 [1]:

  - Drop the now unused DOMAIN_BUS_FSL_MC_MSI bus token

  - Tidy-up fsl_mc_write_msi_msg() while removing the legacy helper

  - Fix include ordering in irq-gic-its-msi-parent.c

  - Various commit message cleanups

  - Collected tags from Ioana and Sascha, with thanks

  - Rebased on top of v7.0.rc1

[1] https://lore.kernel.org/r/20260218135203.2267907-1-maz@kernel.org

Marc Zyngier (6):
  fsl-mc: Remove MSI domain propagation to sub-devices
  fsl-mc: Add minimal infrastructure to use platform MSI
  irqchip/gic-v3-its: Add fsl_mc device plumbing to the msi-parent
    handling
  fsl-mc: Switch over to per-device platform MSI
  fsl-mc: Remove legacy MSI implementation
  platform-msi: Remove stale comment

 drivers/base/platform-msi.c                 |   4 -
 drivers/bus/fsl-mc/dprc-driver.c            |  14 +-
 drivers/bus/fsl-mc/fsl-mc-bus.c             |   4 +-
 drivers/bus/fsl-mc/fsl-mc-msi.c             | 166 +++----------------
 drivers/bus/fsl-mc/fsl-mc-private.h         |   2 +-
 drivers/irqchip/Kconfig                     |   6 -
 drivers/irqchip/Makefile                    |   1 -
 drivers/irqchip/irq-gic-its-msi-parent.c    |   7 +-
 drivers/irqchip/irq-gic-v3-its-fsl-mc-msi.c | 168 --------------------
 include/linux/fsl/mc.h                      |   6 +-
 include/linux/irqdomain_defs.h              |   1 -
 11 files changed, 39 insertions(+), 340 deletions(-)
 delete mode 100644 drivers/irqchip/irq-gic-v3-its-fsl-mc-msi.c

-- 
2.47.3

[PATCH v2 1/6] fsl-mc: Remove MSI domain propagation to sub-devices

[Marc Zyngier]

Only the root device generates MSIs (it is the only one talking to
the ITS), so propagating the domain is pretty pointless. Remove it.

Reviewed-by: Ioana Ciornei <ioana.ciornei@nxp.com>
Tested-by: Ioana Ciornei <ioana.ciornei@nxp.com> # LX2160ARDB, LS2088ARDB
Tested-by: Sascha Bischoff <sascha.bischoff@arm.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
---
 drivers/bus/fsl-mc/fsl-mc-bus.c | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/drivers/bus/fsl-mc/fsl-mc-bus.c b/drivers/bus/fsl-mc/fsl-mc-bus.c
index c117745cf2065..1a6c8e3c0b27f 100644
--- a/drivers/bus/fsl-mc/fsl-mc-bus.c
+++ b/drivers/bus/fsl-mc/fsl-mc-bus.c
@@ -854,14 +854,12 @@ int fsl_mc_device_add(struct fsl_mc_obj_desc *obj_desc,
 	} else {
 		/*
 		 * A non-DPRC object has to be a child of a DPRC, use the
-		 * parent's ICID and interrupt domain.
+		 * parent's ICID.
 		 */
 		mc_dev->icid = parent_mc_dev->icid;
 		mc_dev->dma_mask = FSL_MC_DEFAULT_DMA_MASK;
 		mc_dev->dev.dma_mask = &mc_dev->dma_mask;
 		mc_dev->dev.coherent_dma_mask = mc_dev->dma_mask;
-		dev_set_msi_domain(&mc_dev->dev,
-				   dev_get_msi_domain(&parent_mc_dev->dev));
 	}
 
 	/*
-- 
2.47.3

[PATCH v2 2/6] fsl-mc: Add minimal infrastructure to use platform MSI

[Marc Zyngier]

Add the tiny bit of infrastructure required to use platform MSI
instead of the current hack. This means providing a write_msi_msg
callback, as well as irq domain and devid retrieval helpers.

Reviewed-by: Ioana Ciornei <ioana.ciornei@nxp.com>
Tested-by: Ioana Ciornei <ioana.ciornei@nxp.com> # LX2160ARDB, LS2088ARDB
Tested-by: Sascha Bischoff <sascha.bischoff@arm.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
---
 drivers/bus/fsl-mc/fsl-mc-msi.c     | 50 ++++++++++++++++++++++++-----
 drivers/bus/fsl-mc/fsl-mc-private.h |  1 +
 include/linux/fsl/mc.h              |  2 ++
 3 files changed, 45 insertions(+), 8 deletions(-)

diff --git a/drivers/bus/fsl-mc/fsl-mc-msi.c b/drivers/bus/fsl-mc/fsl-mc-msi.c
index 82cd69f7884c6..c9f50969e88ce 100644
--- a/drivers/bus/fsl-mc/fsl-mc-msi.c
+++ b/drivers/bus/fsl-mc/fsl-mc-msi.c
@@ -110,13 +110,8 @@ static void __fsl_mc_msi_write_msg(struct fsl_mc_device *mc_bus_dev,
 	}
 }
 
-/*
- * NOTE: This function is invoked with interrupts disabled
- */
-static void fsl_mc_msi_write_msg(struct irq_data *irq_data,
-				 struct msi_msg *msg)
+static void fsl_mc_write_msi_msg(struct msi_desc *msi_desc, struct msi_msg *msg)
 {
-	struct msi_desc *msi_desc = irq_data_get_msi_desc(irq_data);
 	struct fsl_mc_device *mc_bus_dev = to_fsl_mc_device(msi_desc->dev);
 	struct fsl_mc_bus *mc_bus = to_fsl_mc_bus(mc_bus_dev);
 	struct fsl_mc_device_irq *mc_dev_irq =
@@ -130,6 +125,17 @@ static void fsl_mc_msi_write_msg(struct irq_data *irq_data,
 	__fsl_mc_msi_write_msg(mc_bus_dev, mc_dev_irq, msi_desc);
 }
 
+/*
+ * NOTE: This function is invoked with interrupts disabled
+ */
+static void fsl_mc_msi_write_msg(struct irq_data *irq_data,
+				 struct msi_msg *msg)
+{
+	struct msi_desc *msi_desc = irq_data_get_msi_desc(irq_data);
+
+	fsl_mc_write_msi_msg(msi_desc, msg);
+}
+
 static void fsl_mc_msi_update_chip_ops(struct msi_domain_info *info)
 {
 	struct irq_chip *chip = info->chip;
@@ -209,6 +215,20 @@ struct irq_domain *fsl_mc_find_msi_domain(struct device *dev)
 	return msi_domain;
 }
 
+struct irq_domain *fsl_mc_get_msi_parent(struct device *dev)
+{
+	struct fsl_mc_device *mc_dev = to_fsl_mc_device(dev);
+	struct device *root_dprc_dev;
+	struct device *bus_dev;
+
+	fsl_mc_get_root_dprc(dev, &root_dprc_dev);
+	bus_dev = root_dprc_dev->parent;
+
+	return (bus_dev->of_node ?
+		of_msi_get_domain(bus_dev, bus_dev->of_node, DOMAIN_BUS_NEXUS) :
+		iort_get_device_domain(bus_dev, mc_dev->icid, DOMAIN_BUS_NEXUS));
+}
+
 int fsl_mc_msi_domain_alloc_irqs(struct device *dev,  unsigned int irq_count)
 {
 	int error = msi_setup_device_data(dev);
@@ -220,8 +240,10 @@ int fsl_mc_msi_domain_alloc_irqs(struct device *dev,  unsigned int irq_count)
 	 * NOTE: Calling this function will trigger the invocation of the
 	 * its_fsl_mc_msi_prepare() callback
 	 */
-	error = msi_domain_alloc_irqs_range(dev, MSI_DEFAULT_DOMAIN, 0, irq_count - 1);
-
+	if (!irq_domain_is_msi_parent(dev_get_msi_domain(dev)))
+		error = msi_domain_alloc_irqs_range(dev, MSI_DEFAULT_DOMAIN, 0, irq_count - 1);
+	else
+		error = platform_device_msi_init_and_alloc_irqs(dev, irq_count, fsl_mc_write_msi_msg);
 	if (error)
 		dev_err(dev, "Failed to allocate IRQs\n");
 	return error;
@@ -231,3 +253,15 @@ void fsl_mc_msi_domain_free_irqs(struct device *dev)
 {
 	msi_domain_free_irqs_all(dev, MSI_DEFAULT_DOMAIN);
 }
+
+u32 fsl_mc_get_msi_id(struct device *dev)
+{
+	struct fsl_mc_device *mc_dev = to_fsl_mc_device(dev);
+	struct device *root_dprc_dev;
+
+	fsl_mc_get_root_dprc(dev, &root_dprc_dev);
+
+	return (root_dprc_dev->parent->of_node ?
+		of_msi_xlate(dev, NULL, mc_dev->icid) :
+		iort_msi_map_id(dev, mc_dev->icid));
+}
diff --git a/drivers/bus/fsl-mc/fsl-mc-private.h b/drivers/bus/fsl-mc/fsl-mc-private.h
index beed4c53533d8..44868f874fd66 100644
--- a/drivers/bus/fsl-mc/fsl-mc-private.h
+++ b/drivers/bus/fsl-mc/fsl-mc-private.h
@@ -642,6 +642,7 @@ int fsl_mc_msi_domain_alloc_irqs(struct device *dev,
 void fsl_mc_msi_domain_free_irqs(struct device *dev);
 
 struct irq_domain *fsl_mc_find_msi_domain(struct device *dev);
+struct irq_domain *fsl_mc_get_msi_parent(struct device *dev);
 
 int __must_check fsl_create_mc_io(struct device *dev,
 				  phys_addr_t mc_portal_phys_addr,
diff --git a/include/linux/fsl/mc.h b/include/linux/fsl/mc.h
index 897d6211c1635..bcc38c0fc230a 100644
--- a/include/linux/fsl/mc.h
+++ b/include/linux/fsl/mc.h
@@ -361,9 +361,11 @@ int mc_send_command(struct fsl_mc_io *mc_io, struct fsl_mc_command *cmd);
 
 #ifdef CONFIG_FSL_MC_BUS
 #define dev_is_fsl_mc(_dev) ((_dev)->bus == &fsl_mc_bus_type)
+u32 fsl_mc_get_msi_id(struct device *dev);
 #else
 /* If fsl-mc bus is not present device cannot belong to fsl-mc bus */
 #define dev_is_fsl_mc(_dev) (0)
+#define fsl_mc_get_msi_id(_dev)	(0)
 #endif
 
 /* Macro to check if a device is a container device */
-- 
2.47.3

[PATCH v2 3/6] irqchip/gic-v3-its: Add fsl_mc device plumbing to the msi-parent handling

[Marc Zyngier]

Make the ITS code aware of fsl_mc devices by plumbing the devid
retrieval primitive.

Reviewed-by: Ioana Ciornei <ioana.ciornei@nxp.com>
Tested-by: Ioana Ciornei <ioana.ciornei@nxp.com> # LX2160ARDB, LS2088ARDB
Tested-by: Sascha Bischoff <sascha.bischoff@arm.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
---
 drivers/irqchip/irq-gic-its-msi-parent.c | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/drivers/irqchip/irq-gic-its-msi-parent.c b/drivers/irqchip/irq-gic-its-msi-parent.c
index a832cdb2e6978..d36b278ae66c5 100644
--- a/drivers/irqchip/irq-gic-its-msi-parent.c
+++ b/drivers/irqchip/irq-gic-its-msi-parent.c
@@ -5,6 +5,7 @@
 // Copyright (C) 2022 Intel
 
 #include <linux/acpi_iort.h>
+#include <linux/fsl/mc.h>
 #include <linux/of_address.h>
 #include <linux/pci.h>
 
@@ -187,9 +188,11 @@ static int its_pmsi_prepare(struct irq_domain *domain, struct device *dev,
 {
 	struct msi_domain_info *msi_info;
 	u32 dev_id;
-	int ret;
+	int ret = 0;
 
-	if (dev->of_node)
+	if (dev_is_fsl_mc(dev))
+		dev_id = fsl_mc_get_msi_id(dev);
+	else if (dev->of_node)
 		ret = of_pmsi_get_msi_info(domain->parent, dev, &dev_id, NULL);
 	else
 		ret = iort_pmsi_get_msi_info(dev, &dev_id, NULL);
-- 
2.47.3

[PATCH v2 4/6] fsl-mc: Switch over to per-device platform MSI

[Marc Zyngier]

Obtain the msi-parent irqdomain instead of the fsl_mc domain,
which magically engages the per-device infrastructure.

Additionally, simplify the overly complicated error handling.

Reviewed-by: Ioana Ciornei <ioana.ciornei@nxp.com>
Tested-by: Ioana Ciornei <ioana.ciornei@nxp.com> # LX2160ARDB, LS2088ARDB
Tested-by: Sascha Bischoff <sascha.bischoff@arm.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
---
 drivers/bus/fsl-mc/dprc-driver.c | 14 +++++---------
 1 file changed, 5 insertions(+), 9 deletions(-)

diff --git a/drivers/bus/fsl-mc/dprc-driver.c b/drivers/bus/fsl-mc/dprc-driver.c
index db67442addad2..a85706826fa06 100644
--- a/drivers/bus/fsl-mc/dprc-driver.c
+++ b/drivers/bus/fsl-mc/dprc-driver.c
@@ -609,9 +609,8 @@ int dprc_setup(struct fsl_mc_device *mc_dev)
 {
 	struct device *parent_dev = mc_dev->dev.parent;
 	struct fsl_mc_bus *mc_bus = to_fsl_mc_bus(mc_dev);
-	struct irq_domain *mc_msi_domain;
+	struct irq_domain *mc_msi_domain = NULL;
 	bool mc_io_created = false;
-	bool msi_domain_set = false;
 	bool uapi_created = false;
 	u16 major_ver, minor_ver;
 	size_t region_size;
@@ -652,14 +651,12 @@ int dprc_setup(struct fsl_mc_device *mc_dev)
 		uapi_created = true;
 	}
 
-	mc_msi_domain = fsl_mc_find_msi_domain(&mc_dev->dev);
-	if (!mc_msi_domain) {
+	mc_msi_domain = fsl_mc_get_msi_parent(&mc_dev->dev);
+	if (!mc_msi_domain)
 		dev_warn(&mc_dev->dev,
 			 "WARNING: MC bus without interrupt support\n");
-	} else {
+	else
 		dev_set_msi_domain(&mc_dev->dev, mc_msi_domain);
-		msi_domain_set = true;
-	}
 
 	error = dprc_open(mc_dev->mc_io, 0, mc_dev->obj_desc.id,
 			  &mc_dev->mc_handle);
@@ -699,8 +696,7 @@ int dprc_setup(struct fsl_mc_device *mc_dev)
 	(void)dprc_close(mc_dev->mc_io, 0, mc_dev->mc_handle);
 
 error_cleanup_msi_domain:
-	if (msi_domain_set)
-		dev_set_msi_domain(&mc_dev->dev, NULL);
+	dev_set_msi_domain(&mc_dev->dev, NULL);
 
 	if (mc_io_created) {
 		fsl_destroy_mc_io(mc_dev->mc_io);
-- 
2.47.3

[PATCH v2 5/6] fsl-mc: Remove legacy MSI implementation

[Marc Zyngier]

Get rid of most of the fsl_mc MSI infrastructure, which is now replaced
by common code.

Reviewed-by: Ioana Ciornei <ioana.ciornei@nxp.com>
Tested-by: Ioana Ciornei <ioana.ciornei@nxp.com> # LX2160ARDB, LS2088ARDB
Tested-by: Sascha Bischoff <sascha.bischoff@arm.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
---
 drivers/bus/fsl-mc/fsl-mc-msi.c             | 166 +------------------
 drivers/bus/fsl-mc/fsl-mc-private.h         |   1 -
 drivers/irqchip/Kconfig                     |   6 -
 drivers/irqchip/Makefile                    |   1 -
 drivers/irqchip/irq-gic-v3-its-fsl-mc-msi.c | 168 --------------------
 include/linux/fsl/mc.h                      |   4 -
 include/linux/irqdomain_defs.h              |   1 -
 7 files changed, 8 insertions(+), 339 deletions(-)
 delete mode 100644 drivers/irqchip/irq-gic-v3-its-fsl-mc-msi.c

diff --git a/drivers/bus/fsl-mc/fsl-mc-msi.c b/drivers/bus/fsl-mc/fsl-mc-msi.c
index c9f50969e88ce..be38b43803dea 100644
--- a/drivers/bus/fsl-mc/fsl-mc-msi.c
+++ b/drivers/bus/fsl-mc/fsl-mc-msi.c
@@ -15,53 +15,16 @@
 
 #include "fsl-mc-private.h"
 
-#ifdef GENERIC_MSI_DOMAIN_OPS
-/*
- * Generate a unique ID identifying the interrupt (only used within the MSI
- * irqdomain.  Combine the icid with the interrupt index.
- */
-static irq_hw_number_t fsl_mc_domain_calc_hwirq(struct fsl_mc_device *dev,
-						struct msi_desc *desc)
-{
-	/*
-	 * Make the base hwirq value for ICID*10000 so it is readable
-	 * as a decimal value in /proc/interrupts.
-	 */
-	return (irq_hw_number_t)(desc->msi_index + (dev->icid * 10000));
-}
-
-static void fsl_mc_msi_set_desc(msi_alloc_info_t *arg,
-				struct msi_desc *desc)
-{
-	arg->desc = desc;
-	arg->hwirq = fsl_mc_domain_calc_hwirq(to_fsl_mc_device(desc->dev),
-					      desc);
-}
-#else
-#define fsl_mc_msi_set_desc NULL
-#endif
-
-static void fsl_mc_msi_update_dom_ops(struct msi_domain_info *info)
-{
-	struct msi_domain_ops *ops = info->ops;
-
-	if (!ops)
-		return;
-
-	/*
-	 * set_desc should not be set by the caller
-	 */
-	if (!ops->set_desc)
-		ops->set_desc = fsl_mc_msi_set_desc;
-}
-
-static void __fsl_mc_msi_write_msg(struct fsl_mc_device *mc_bus_dev,
-				   struct fsl_mc_device_irq *mc_dev_irq,
-				   struct msi_desc *msi_desc)
+static void fsl_mc_write_msi_msg(struct msi_desc *msi_desc, struct msi_msg *msg)
 {
-	int error;
+	struct fsl_mc_device *mc_bus_dev = to_fsl_mc_device(msi_desc->dev);
+	struct fsl_mc_bus *mc_bus = to_fsl_mc_bus(mc_bus_dev);
+	struct fsl_mc_device_irq *mc_dev_irq = &mc_bus->irq_resources[msi_desc->msi_index];
 	struct fsl_mc_device *owner_mc_dev = mc_dev_irq->mc_dev;
 	struct dprc_irq_cfg irq_cfg;
+	int error;
+
+	msi_desc->msg = *msg;
 
 	/*
 	 * msi_desc->msg.address is 0x0 when this function is invoked in
@@ -110,111 +73,6 @@ static void __fsl_mc_msi_write_msg(struct fsl_mc_device *mc_bus_dev,
 	}
 }
 
-static void fsl_mc_write_msi_msg(struct msi_desc *msi_desc, struct msi_msg *msg)
-{
-	struct fsl_mc_device *mc_bus_dev = to_fsl_mc_device(msi_desc->dev);
-	struct fsl_mc_bus *mc_bus = to_fsl_mc_bus(mc_bus_dev);
-	struct fsl_mc_device_irq *mc_dev_irq =
-		&mc_bus->irq_resources[msi_desc->msi_index];
-
-	msi_desc->msg = *msg;
-
-	/*
-	 * Program the MSI (paddr, value) pair in the device:
-	 */
-	__fsl_mc_msi_write_msg(mc_bus_dev, mc_dev_irq, msi_desc);
-}
-
-/*
- * NOTE: This function is invoked with interrupts disabled
- */
-static void fsl_mc_msi_write_msg(struct irq_data *irq_data,
-				 struct msi_msg *msg)
-{
-	struct msi_desc *msi_desc = irq_data_get_msi_desc(irq_data);
-
-	fsl_mc_write_msi_msg(msi_desc, msg);
-}
-
-static void fsl_mc_msi_update_chip_ops(struct msi_domain_info *info)
-{
-	struct irq_chip *chip = info->chip;
-
-	if (!chip)
-		return;
-
-	/*
-	 * irq_write_msi_msg should not be set by the caller
-	 */
-	if (!chip->irq_write_msi_msg)
-		chip->irq_write_msi_msg = fsl_mc_msi_write_msg;
-}
-
-/**
- * fsl_mc_msi_create_irq_domain - Create a fsl-mc MSI interrupt domain
- * @fwnode:	Optional firmware node of the interrupt controller
- * @info:	MSI domain info
- * @parent:	Parent irq domain
- *
- * Updates the domain and chip ops and creates a fsl-mc MSI
- * interrupt domain.
- *
- * Returns:
- * A domain pointer or NULL in case of failure.
- */
-struct irq_domain *fsl_mc_msi_create_irq_domain(struct fwnode_handle *fwnode,
-						struct msi_domain_info *info,
-						struct irq_domain *parent)
-{
-	struct irq_domain *domain;
-
-	if (WARN_ON((info->flags & MSI_FLAG_LEVEL_CAPABLE)))
-		info->flags &= ~MSI_FLAG_LEVEL_CAPABLE;
-	if (info->flags & MSI_FLAG_USE_DEF_DOM_OPS)
-		fsl_mc_msi_update_dom_ops(info);
-	if (info->flags & MSI_FLAG_USE_DEF_CHIP_OPS)
-		fsl_mc_msi_update_chip_ops(info);
-	info->flags |= MSI_FLAG_ALLOC_SIMPLE_MSI_DESCS | MSI_FLAG_FREE_MSI_DESCS;
-
-	domain = msi_create_irq_domain(fwnode, info, parent);
-	if (domain)
-		irq_domain_update_bus_token(domain, DOMAIN_BUS_FSL_MC_MSI);
-
-	return domain;
-}
-
-struct irq_domain *fsl_mc_find_msi_domain(struct device *dev)
-{
-	struct device *root_dprc_dev;
-	struct device *bus_dev;
-	struct irq_domain *msi_domain;
-	struct fsl_mc_device *mc_dev = to_fsl_mc_device(dev);
-
-	fsl_mc_get_root_dprc(dev, &root_dprc_dev);
-	bus_dev = root_dprc_dev->parent;
-
-	if (bus_dev->of_node) {
-		msi_domain = of_msi_map_get_device_domain(dev,
-						  mc_dev->icid,
-						  DOMAIN_BUS_FSL_MC_MSI);
-
-		/*
-		 * if the msi-map property is missing assume that all the
-		 * child containers inherit the domain from the parent
-		 */
-		if (!msi_domain)
-
-			msi_domain = of_msi_get_domain(bus_dev,
-						bus_dev->of_node,
-						DOMAIN_BUS_FSL_MC_MSI);
-	} else {
-		msi_domain = iort_get_device_domain(dev, mc_dev->icid,
-						    DOMAIN_BUS_FSL_MC_MSI);
-	}
-
-	return msi_domain;
-}
-
 struct irq_domain *fsl_mc_get_msi_parent(struct device *dev)
 {
 	struct fsl_mc_device *mc_dev = to_fsl_mc_device(dev);
@@ -232,18 +90,10 @@ struct irq_domain *fsl_mc_get_msi_parent(struct device *dev)
 int fsl_mc_msi_domain_alloc_irqs(struct device *dev,  unsigned int irq_count)
 {
 	int error = msi_setup_device_data(dev);
-
 	if (error)
 		return error;
 
-	/*
-	 * NOTE: Calling this function will trigger the invocation of the
-	 * its_fsl_mc_msi_prepare() callback
-	 */
-	if (!irq_domain_is_msi_parent(dev_get_msi_domain(dev)))
-		error = msi_domain_alloc_irqs_range(dev, MSI_DEFAULT_DOMAIN, 0, irq_count - 1);
-	else
-		error = platform_device_msi_init_and_alloc_irqs(dev, irq_count, fsl_mc_write_msi_msg);
+	error = platform_device_msi_init_and_alloc_irqs(dev, irq_count, fsl_mc_write_msi_msg);
 	if (error)
 		dev_err(dev, "Failed to allocate IRQs\n");
 	return error;
diff --git a/drivers/bus/fsl-mc/fsl-mc-private.h b/drivers/bus/fsl-mc/fsl-mc-private.h
index 44868f874fd66..197edcc8cde46 100644
--- a/drivers/bus/fsl-mc/fsl-mc-private.h
+++ b/drivers/bus/fsl-mc/fsl-mc-private.h
@@ -641,7 +641,6 @@ int fsl_mc_msi_domain_alloc_irqs(struct device *dev,
 
 void fsl_mc_msi_domain_free_irqs(struct device *dev);
 
-struct irq_domain *fsl_mc_find_msi_domain(struct device *dev);
 struct irq_domain *fsl_mc_get_msi_parent(struct device *dev);
 
 int __must_check fsl_create_mc_io(struct device *dev,
diff --git a/drivers/irqchip/Kconfig b/drivers/irqchip/Kconfig
index f07b00d7fef90..3e5b2040cb4ef 100644
--- a/drivers/irqchip/Kconfig
+++ b/drivers/irqchip/Kconfig
@@ -51,12 +51,6 @@ config ARM_GIC_V3_ITS
 	default ARM_GIC_V3
 	select IRQ_MSI_IOMMU
 
-config ARM_GIC_V3_ITS_FSL_MC
-	bool
-	depends on ARM_GIC_V3_ITS
-	depends on FSL_MC_BUS
-	default ARM_GIC_V3_ITS
-
 config ARM_GIC_V5
 	bool
 	select IRQ_DOMAIN_HIERARCHY
diff --git a/drivers/irqchip/Makefile b/drivers/irqchip/Makefile
index 26aa3b6ec99fd..d5a28cee0d8eb 100644
--- a/drivers/irqchip/Makefile
+++ b/drivers/irqchip/Makefile
@@ -35,7 +35,6 @@ obj-$(CONFIG_ARM_GIC_V2M)		+= irq-gic-v2m.o
 obj-$(CONFIG_ARM_GIC_V3)		+= irq-gic-v3.o irq-gic-v3-mbi.o irq-gic-common.o
 obj-$(CONFIG_ARM_GIC_ITS_PARENT)	+= irq-gic-its-msi-parent.o
 obj-$(CONFIG_ARM_GIC_V3_ITS)		+= irq-gic-v3-its.o irq-gic-v4.o
-obj-$(CONFIG_ARM_GIC_V3_ITS_FSL_MC)	+= irq-gic-v3-its-fsl-mc-msi.o
 obj-$(CONFIG_ARM_GIC_V5)		+= irq-gic-v5.o irq-gic-v5-irs.o irq-gic-v5-its.o \
 					   irq-gic-v5-iwb.o
 obj-$(CONFIG_HISILICON_IRQ_MBIGEN)	+= irq-mbigen.o
diff --git a/drivers/irqchip/irq-gic-v3-its-fsl-mc-msi.c b/drivers/irqchip/irq-gic-v3-its-fsl-mc-msi.c
deleted file mode 100644
index b5785472765a3..0000000000000
--- a/drivers/irqchip/irq-gic-v3-its-fsl-mc-msi.c
+++ /dev/null
@@ -1,168 +0,0 @@
-// SPDX-License-Identifier: GPL-2.0
-/*
- * Freescale Management Complex (MC) bus driver MSI support
- *
- * Copyright (C) 2015-2016 Freescale Semiconductor, Inc.
- * Author: German Rivera <German.Rivera@freescale.com>
- *
- */
-
-#include <linux/acpi.h>
-#include <linux/acpi_iort.h>
-#include <linux/irq.h>
-#include <linux/msi.h>
-#include <linux/of.h>
-#include <linux/of_irq.h>
-#include <linux/fsl/mc.h>
-
-static struct irq_chip its_msi_irq_chip = {
-	.name = "ITS-fMSI",
-	.irq_mask = irq_chip_mask_parent,
-	.irq_unmask = irq_chip_unmask_parent,
-	.irq_eoi = irq_chip_eoi_parent,
-	.irq_set_affinity = msi_domain_set_affinity
-};
-
-static u32 fsl_mc_msi_domain_get_msi_id(struct irq_domain *domain,
-					struct fsl_mc_device *mc_dev)
-{
-	struct device_node *of_node;
-	u32 out_id;
-
-	of_node = irq_domain_get_of_node(domain);
-	out_id = of_node ? of_msi_xlate(&mc_dev->dev, &of_node, mc_dev->icid) :
-			iort_msi_map_id(&mc_dev->dev, mc_dev->icid);
-
-	return out_id;
-}
-
-static int its_fsl_mc_msi_prepare(struct irq_domain *msi_domain,
-				  struct device *dev,
-				  int nvec, msi_alloc_info_t *info)
-{
-	struct fsl_mc_device *mc_bus_dev;
-	struct msi_domain_info *msi_info;
-
-	if (!dev_is_fsl_mc(dev))
-		return -EINVAL;
-
-	mc_bus_dev = to_fsl_mc_device(dev);
-	if (!(mc_bus_dev->flags & FSL_MC_IS_DPRC))
-		return -EINVAL;
-
-	/*
-	 * Set the device Id to be passed to the GIC-ITS:
-	 *
-	 * NOTE: This device id corresponds to the IOMMU stream ID
-	 * associated with the DPRC object (ICID).
-	 */
-	info->scratchpad[0].ul = fsl_mc_msi_domain_get_msi_id(msi_domain,
-							      mc_bus_dev);
-	msi_info = msi_get_domain_info(msi_domain->parent);
-
-	/* Allocate at least 32 MSIs, and always as a power of 2 */
-	nvec = max_t(int, 32, roundup_pow_of_two(nvec));
-	return msi_info->ops->msi_prepare(msi_domain->parent, dev, nvec, info);
-}
-
-static struct msi_domain_ops its_fsl_mc_msi_ops __ro_after_init = {
-	.msi_prepare = its_fsl_mc_msi_prepare,
-};
-
-static struct msi_domain_info its_fsl_mc_msi_domain_info = {
-	.flags	= (MSI_FLAG_USE_DEF_DOM_OPS | MSI_FLAG_USE_DEF_CHIP_OPS),
-	.ops	= &its_fsl_mc_msi_ops,
-	.chip	= &its_msi_irq_chip,
-};
-
-static const struct of_device_id its_device_id[] = {
-	{	.compatible	= "arm,gic-v3-its",	},
-	{},
-};
-
-static void __init its_fsl_mc_msi_init_one(struct fwnode_handle *handle,
-					  const char *name)
-{
-	struct irq_domain *parent;
-	struct irq_domain *mc_msi_domain;
-
-	parent = irq_find_matching_fwnode(handle, DOMAIN_BUS_NEXUS);
-	if (!parent || !msi_get_domain_info(parent)) {
-		pr_err("%s: unable to locate ITS domain\n", name);
-		return;
-	}
-
-	mc_msi_domain = fsl_mc_msi_create_irq_domain(handle,
-						&its_fsl_mc_msi_domain_info,
-						parent);
-	if (!mc_msi_domain) {
-		pr_err("%s: unable to create fsl-mc domain\n", name);
-		return;
-	}
-
-	pr_info("fsl-mc MSI: %s domain created\n", name);
-}
-
-#ifdef CONFIG_ACPI
-static int __init
-its_fsl_mc_msi_parse_madt(union acpi_subtable_headers *header,
-			  const unsigned long end)
-{
-	struct acpi_madt_generic_translator *its_entry;
-	struct fwnode_handle *dom_handle;
-	const char *node_name;
-	int err = 0;
-
-	its_entry = (struct acpi_madt_generic_translator *)header;
-	node_name = kasprintf(GFP_KERNEL, "ITS@0x%lx",
-			      (long)its_entry->base_address);
-
-	dom_handle = iort_find_domain_token(its_entry->translation_id);
-	if (!dom_handle) {
-		pr_err("%s: Unable to locate ITS domain handle\n", node_name);
-		err = -ENXIO;
-		goto out;
-	}
-
-	its_fsl_mc_msi_init_one(dom_handle, node_name);
-
-out:
-	kfree(node_name);
-	return err;
-}
-
-
-static void __init its_fsl_mc_acpi_msi_init(void)
-{
-	acpi_table_parse_madt(ACPI_MADT_TYPE_GENERIC_TRANSLATOR,
-			      its_fsl_mc_msi_parse_madt, 0);
-}
-#else
-static inline void its_fsl_mc_acpi_msi_init(void) { }
-#endif
-
-static void __init its_fsl_mc_of_msi_init(void)
-{
-	struct device_node *np;
-
-	for (np = of_find_matching_node(NULL, its_device_id); np;
-	     np = of_find_matching_node(np, its_device_id)) {
-		if (!of_device_is_available(np))
-			continue;
-		if (!of_property_read_bool(np, "msi-controller"))
-			continue;
-
-		its_fsl_mc_msi_init_one(of_fwnode_handle(np),
-					np->full_name);
-	}
-}
-
-static int __init its_fsl_mc_msi_init(void)
-{
-	its_fsl_mc_of_msi_init();
-	its_fsl_mc_acpi_msi_init();
-
-	return 0;
-}
-
-early_initcall(its_fsl_mc_msi_init);
diff --git a/include/linux/fsl/mc.h b/include/linux/fsl/mc.h
index bcc38c0fc230a..e9522233f9b57 100644
--- a/include/linux/fsl/mc.h
+++ b/include/linux/fsl/mc.h
@@ -425,10 +425,6 @@ int __must_check fsl_mc_object_allocate(struct fsl_mc_device *mc_dev,
 
 void fsl_mc_object_free(struct fsl_mc_device *mc_adev);
 
-struct irq_domain *fsl_mc_msi_create_irq_domain(struct fwnode_handle *fwnode,
-						struct msi_domain_info *info,
-						struct irq_domain *parent);
-
 int __must_check fsl_mc_allocate_irqs(struct fsl_mc_device *mc_dev);
 
 void fsl_mc_free_irqs(struct fsl_mc_device *mc_dev);
diff --git a/include/linux/irqdomain_defs.h b/include/linux/irqdomain_defs.h
index 36653e2ee1c92..3a03bdfeeee93 100644
--- a/include/linux/irqdomain_defs.h
+++ b/include/linux/irqdomain_defs.h
@@ -17,7 +17,6 @@ enum irq_domain_bus_token {
 	DOMAIN_BUS_PLATFORM_MSI,
 	DOMAIN_BUS_NEXUS,
 	DOMAIN_BUS_IPI,
-	DOMAIN_BUS_FSL_MC_MSI,
 	DOMAIN_BUS_TI_SCI_INTA_MSI,
 	DOMAIN_BUS_WAKEUP,
 	DOMAIN_BUS_VMD_MSI,
-- 
2.47.3

[PATCH v2 6/6] platform-msi: Remove stale comment

[Marc Zyngier]

The backward compatibility code for the previous incarnation of
platform MSI was removed in e9894248994ca ("genirq/msi: Remove
platform MSI leftovers"), but the comment about that removal is
still present.  Remove it.

Reviewed-by: Ioana Ciornei <ioana.ciornei@nxp.com>
Tested-by: Ioana Ciornei <ioana.ciornei@nxp.com> # LX2160ARDB, LS2088ARDB
Tested-by: Sascha Bischoff <sascha.bischoff@arm.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
---
 drivers/base/platform-msi.c | 4 ----
 1 file changed, 4 deletions(-)

diff --git a/drivers/base/platform-msi.c b/drivers/base/platform-msi.c
index 70db08f3ac6fa..69eed058eb208 100644
--- a/drivers/base/platform-msi.c
+++ b/drivers/base/platform-msi.c
@@ -61,10 +61,6 @@ static const struct msi_domain_template platform_msi_template = {
  * parent. The parent domain sets up the new domain. The domain has
  * a fixed size of @nvec. The domain is managed by devres and will
  * be removed when the device is removed.
- *
- * Note: For migration purposes this falls back to the original platform_msi code
- *	 up to the point where all platforms have been converted to the MSI
- *	 parent model.
  */
 int platform_device_msi_init_and_alloc_irqs(struct device *dev, unsigned int nvec,
 					    irq_write_msi_msg_t write_msi_msg)
-- 
2.47.3

Re: [PATCH v2 0/6] fsl-mc: Move over to device MSI infrastructure

[Thomas Gleixner]

On Tue, Feb 24 2026 at 10:09, Marc Zyngier wrote:

> This is the second drop of this cleanup series for the fsl-mc MSI
> infrastructure, initially posted at [1].
>
> * From v1 [1]:
>
>   - Drop the now unused DOMAIN_BUS_FSL_MC_MSI bus token
>
>   - Tidy-up fsl_mc_write_msi_msg() while removing the legacy helper
>
>   - Fix include ordering in irq-gic-its-msi-parent.c
>
>   - Various commit message cleanups
>
>   - Collected tags from Ioana and Sascha, with thanks
>
>   - Rebased on top of v7.0.rc1
>
> [1] https://lore.kernel.org/r/20260218135203.2267907-1-maz@kernel.org

Acked-by: Thomas Gleixner <tglx@kernel.org>

in case this goes through the FSL SoC tree. If not, please let me know
and I pick it up.

Thanks,

        tglx

Re: [PATCH v2 0/6] fsl-mc: Move over to device MSI infrastructure

[Christophe Leroy (CS GROUP)]

On Tue, 24 Feb 2026 10:09:30 +0000, Marc Zyngier wrote:
> This is the second drop of this cleanup series for the fsl-mc MSI
> infrastructure, initially posted at [1].
> 
> * From v1 [1]:
> 
>   - Drop the now unused DOMAIN_BUS_FSL_MC_MSI bus token
> 
> [...]

Applied, thanks!

[1/6] fsl-mc: Remove MSI domain propagation to sub-devices
      commit: 1fb7392ee3408494d4d62c09a8c3e5f5934caba7
[2/6] fsl-mc: Add minimal infrastructure to use platform MSI
      commit: 0c9f522f2d41c7e055a602a0d2c41dc7af01010b
[3/6] irqchip/gic-v3-its: Add fsl_mc device plumbing to the msi-parent handling
      commit: cf3179b4e53f527aba9f0c6c3b921619c8adf761
[4/6] fsl-mc: Switch over to per-device platform MSI
      commit: 4a958e47c246fa3fb8954f4303e0da15ab3d026d
[5/6] fsl-mc: Remove legacy MSI implementation
      commit: 14b1cbcc6cec0b02298f4adf717646cd943b7ef6
[6/6] platform-msi: Remove stale comment
      commit: f0a2eac6a597268034fd40d92c1469182438b53d

Best regards,
-- 
Christophe Leroy (CS GROUP) <chleroy@kernel.org>