[PATCH v3 00/14] PCI/MSI: Getting rid of msi_controller, and other cleanups

@@ -41,7 +41,6 @@ config PCI_TEGRA
 	bool "NVIDIA Tegra PCIe controller"
 	depends on ARCH_TEGRA || COMPILE_TEST
 	depends on PCI_MSI_IRQ_DOMAIN
-	select PCI_MSI_ARCH_FALLBACKS
 	help
 	  Say Y here if you want support for the PCIe host controller found
 	  on NVIDIA Tegra SoCs.

@@ -21,6 +21,7 @@
 #include <linux/interrupt.h>
 #include <linux/iopoll.h>
 #include <linux/irq.h>
+#include <linux/irqchip/chained_irq.h>
 #include <linux/irqdomain.h>
 #include <linux/kernel.h>
 #include <linux/init.h>

@@ -78,23 +79,8 @@
 #define AFI_MSI_FPCI_BAR_ST	0x64
 #define AFI_MSI_AXI_BAR_ST	0x68
 
-#define AFI_MSI_VEC0		0x6c
-#define AFI_MSI_VEC1		0x70
-#define AFI_MSI_VEC2		0x74
-#define AFI_MSI_VEC3		0x78
-#define AFI_MSI_VEC4		0x7c
-#define AFI_MSI_VEC5		0x80
-#define AFI_MSI_VEC6		0x84
-#define AFI_MSI_VEC7		0x88
-
-#define AFI_MSI_EN_VEC0		0x8c
-#define AFI_MSI_EN_VEC1		0x90
-#define AFI_MSI_EN_VEC2		0x94
-#define AFI_MSI_EN_VEC3		0x98
-#define AFI_MSI_EN_VEC4		0x9c
-#define AFI_MSI_EN_VEC5		0xa0
-#define AFI_MSI_EN_VEC6		0xa4
-#define AFI_MSI_EN_VEC7		0xa8
+#define AFI_MSI_VEC(x)		(0x6c + ((x) * 4))
+#define AFI_MSI_EN_VEC(x)	(0x8c + ((x) * 4))
 
 #define AFI_CONFIGURATION		0xac
 #define  AFI_CONFIGURATION_EN_FPCI		(1 << 0)

@@ -280,10 +266,10 @@
 #define LINK_RETRAIN_TIMEOUT 100000 /* in usec */
 
 struct tegra_msi {
-	struct msi_controller chip;
 	DECLARE_BITMAP(used, INT_PCI_MSI_NR);
 	struct irq_domain *domain;
-	struct mutex lock;
+	struct mutex map_lock;
+	spinlock_t mask_lock;
 	void *virt;
 	dma_addr_t phys;
 	int irq;

@@ -333,11 +319,6 @@ struct tegra_pcie_soc {
 	} ectl;
 };
 
-static inline struct tegra_msi *to_tegra_msi(struct msi_controller *chip)
-{
-	return container_of(chip, struct tegra_msi, chip);
-}
-
 struct tegra_pcie {
 	struct device *dev;
 

@@ -372,6 +353,11 @@ struct tegra_pcie {
 	struct dentry *debugfs;
 };
 
+static inline struct tegra_pcie *msi_to_pcie(struct tegra_msi *msi)
+{
+	return container_of(msi, struct tegra_pcie, msi);
+}
+
 struct tegra_pcie_port {
 	struct tegra_pcie *pcie;
 	struct device_node *np;

@@ -1432,7 +1418,6 @@ static void tegra_pcie_phys_put(struct tegra_pcie *pcie)
 	}
 }
 
-
 static int tegra_pcie_get_resources(struct tegra_pcie *pcie)
 {
 	struct device *dev = pcie->dev;

@@ -1509,6 +1494,7 @@ static int tegra_pcie_get_resources(struct tegra_pcie *pcie)
 phys_put:
 	if (soc->program_uphy)
 		tegra_pcie_phys_put(pcie);
+
 	return err;
 }
 

@@ -1551,161 +1537,227 @@ static void tegra_pcie_pme_turnoff(struct tegra_pcie_port *port)
 	afi_writel(pcie, val, AFI_PCIE_PME);
 }
 
-static int tegra_msi_alloc(struct tegra_msi *chip)
-{
-	int msi;
-
-	mutex_lock(&chip->lock);
-
-	msi = find_first_zero_bit(chip->used, INT_PCI_MSI_NR);
-	if (msi < INT_PCI_MSI_NR)
-		set_bit(msi, chip->used);
-	else
-		msi = -ENOSPC;
-
-	mutex_unlock(&chip->lock);
-
-	return msi;
-}
-
-static void tegra_msi_free(struct tegra_msi *chip, unsigned long irq)
+static void tegra_pcie_msi_irq(struct irq_desc *desc)
 {
-	struct device *dev = chip->chip.dev;
-
-	mutex_lock(&chip->lock);
-
-	if (!test_bit(irq, chip->used))
-		dev_err(dev, "trying to free unused MSI#%lu\n", irq);
-	else
-		clear_bit(irq, chip->used);
-
-	mutex_unlock(&chip->lock);
-}
-
-static irqreturn_t tegra_pcie_msi_irq(int irq, void *data)
-{
-	struct tegra_pcie *pcie = data;
-	struct device *dev = pcie->dev;
+	struct tegra_pcie *pcie = irq_desc_get_handler_data(desc);
+	struct irq_chip *chip = irq_desc_get_chip(desc);
 	struct tegra_msi *msi = &pcie->msi;
-	unsigned int i, processed = 0;
+	struct device *dev = pcie->dev;
+	unsigned int i;
+
+	chained_irq_enter(chip, desc);
 
 	for (i = 0; i < 8; i++) {
-		unsigned long reg = afi_readl(pcie, AFI_MSI_VEC0 + i * 4);
+		unsigned long reg = afi_readl(pcie, AFI_MSI_VEC(i));
 
 		while (reg) {
 			unsigned int offset = find_first_bit(&reg, 32);
 			unsigned int index = i * 32 + offset;
 			unsigned int irq;
 
-			/* clear the interrupt */
-			afi_writel(pcie, 1 << offset, AFI_MSI_VEC0 + i * 4);
-
-			irq = irq_find_mapping(msi->domain, index);
+			irq = irq_find_mapping(msi->domain->parent, index);
 			if (irq) {
-				if (test_bit(index, msi->used))
-					generic_handle_irq(irq);
-				else
-					dev_info(dev, "unhandled MSI\n");
+				generic_handle_irq(irq);
 			} else {
 				/*
 				 * that's weird who triggered this?
 				 * just clear it
 				 */
 				dev_info(dev, "unexpected MSI\n");
+				afi_writel(pcie, BIT(index % 32), AFI_MSI_VEC(index));
 			}
 
 			/* see if there's any more pending in this vector */
-			reg = afi_readl(pcie, AFI_MSI_VEC0 + i * 4);
-
-			processed++;
+			reg = afi_readl(pcie, AFI_MSI_VEC(i));
 		}
 	}
 
-	return processed > 0 ? IRQ_HANDLED : IRQ_NONE;
+	chained_irq_exit(chip, desc);
 }
 
-static int tegra_msi_setup_irq(struct msi_controller *chip,
-			       struct pci_dev *pdev, struct msi_desc *desc)
+static void tegra_msi_top_irq_ack(struct irq_data *d)
 {
-	struct tegra_msi *msi = to_tegra_msi(chip);
-	struct msi_msg msg;
-	unsigned int irq;
-	int hwirq;
+	irq_chip_ack_parent(d);
+}
 
-	hwirq = tegra_msi_alloc(msi);
-	if (hwirq < 0)
-		return hwirq;
+static void tegra_msi_top_irq_mask(struct irq_data *d)
+{
+	pci_msi_mask_irq(d);
+	irq_chip_mask_parent(d);
+}
 
-	irq = irq_create_mapping(msi->domain, hwirq);
-	if (!irq) {
-		tegra_msi_free(msi, hwirq);
-		return -EINVAL;
-	}
+static void tegra_msi_top_irq_unmask(struct irq_data *d)
+{
+	pci_msi_unmask_irq(d);
+	irq_chip_unmask_parent(d);
+}
+
+static struct irq_chip tegra_msi_top_chip = {
+	.name		= "tegra PCIe MSI",
+	.irq_ack	= tegra_msi_top_irq_ack,
+	.irq_mask	= tegra_msi_top_irq_mask,
+	.irq_unmask	= tegra_msi_top_irq_unmask,
+};
 
-	irq_set_msi_desc(irq, desc);
+static void tegra_msi_irq_ack(struct irq_data *d)
+{
+	struct tegra_msi *msi = irq_data_get_irq_chip_data(d);
+	struct tegra_pcie *pcie = msi_to_pcie(msi);
+	unsigned int index = d->hwirq / 32;
 
-	msg.address_lo = lower_32_bits(msi->phys);
-	msg.address_hi = upper_32_bits(msi->phys);
-	msg.data = hwirq;
+	/* clear the interrupt */
+	afi_writel(pcie, BIT(d->hwirq % 32), AFI_MSI_VEC(index));
+}
 
-	pci_write_msi_msg(irq, &msg);
+static void tegra_msi_irq_mask(struct irq_data *d)
+{
+	struct tegra_msi *msi = irq_data_get_irq_chip_data(d);
+	struct tegra_pcie *pcie = msi_to_pcie(msi);
+	unsigned int index = d->hwirq / 32;
+	unsigned long flags;
+	u32 value;
 
-	return 0;
+	spin_lock_irqsave(&msi->mask_lock, flags);
+	value = afi_readl(pcie, AFI_MSI_EN_VEC(index));
+	value &= ~BIT(d->hwirq % 32);
+	afi_writel(pcie, value, AFI_MSI_EN_VEC(index));
+	spin_unlock_irqrestore(&msi->mask_lock, flags);
+}
+
+static void tegra_msi_irq_unmask(struct irq_data *d)
+{
+	struct tegra_msi *msi = irq_data_get_irq_chip_data(d);
+	struct tegra_pcie *pcie = msi_to_pcie(msi);
+	unsigned int index = d->hwirq / 32;
+	unsigned long flags;
+	u32 value;
+
+	spin_lock_irqsave(&msi->mask_lock, flags);
+	value = afi_readl(pcie, AFI_MSI_EN_VEC(index));
+	value |= BIT(d->hwirq % 32);
+	afi_writel(pcie, value, AFI_MSI_EN_VEC(index));
+	spin_unlock_irqrestore(&msi->mask_lock, flags);
+}
+
+static int tegra_msi_set_affinity(struct irq_data *d, const struct cpumask *mask, bool force)
+{
+	return -EINVAL;
 }
 
-static void tegra_msi_teardown_irq(struct msi_controller *chip,
-				   unsigned int irq)
+static void tegra_compose_msi_msg(struct irq_data *data, struct msi_msg *msg)
 {
-	struct tegra_msi *msi = to_tegra_msi(chip);
-	struct irq_data *d = irq_get_irq_data(irq);
-	irq_hw_number_t hwirq = irqd_to_hwirq(d);
+	struct tegra_msi *msi = irq_data_get_irq_chip_data(data);
 
-	irq_dispose_mapping(irq);
-	tegra_msi_free(msi, hwirq);
+	msg->address_lo = lower_32_bits(msi->phys);
+	msg->address_hi = upper_32_bits(msi->phys);
+	msg->data = data->hwirq;
 }
 
-static struct irq_chip tegra_msi_irq_chip = {
-	.name = "Tegra PCIe MSI",
-	.irq_enable = pci_msi_unmask_irq,
-	.irq_disable = pci_msi_mask_irq,
-	.irq_mask = pci_msi_mask_irq,
-	.irq_unmask = pci_msi_unmask_irq,
+static struct irq_chip tegra_msi_bottom_chip = {
+	.name			= "Tegra MSI",
+	.irq_ack		= tegra_msi_irq_ack,
+	.irq_mask		= tegra_msi_irq_mask,
+	.irq_unmask		= tegra_msi_irq_unmask,
+	.irq_set_affinity 	= tegra_msi_set_affinity,
+	.irq_compose_msi_msg	= tegra_compose_msi_msg,
 };
 
-static int tegra_msi_map(struct irq_domain *domain, unsigned int irq,
-			 irq_hw_number_t hwirq)
+static int tegra_msi_domain_alloc(struct irq_domain *domain, unsigned int virq,
+				  unsigned int nr_irqs, void *args)
 {
-	irq_set_chip_and_handler(irq, &tegra_msi_irq_chip, handle_simple_irq);
-	irq_set_chip_data(irq, domain->host_data);
+	struct tegra_msi *msi = domain->host_data;
+	unsigned int i;
+	int hwirq;
+
+	mutex_lock(&msi->map_lock);
+
+	hwirq = bitmap_find_free_region(msi->used, INT_PCI_MSI_NR, order_base_2(nr_irqs));
+
+	mutex_unlock(&msi->map_lock);
+
+	if (hwirq < 0)
+		return -ENOSPC;
+
+	for (i = 0; i < nr_irqs; i++)
+		irq_domain_set_info(domain, virq + i, hwirq + i,
+				    &tegra_msi_bottom_chip, domain->host_data,
+				    handle_edge_irq, NULL, NULL);
 
 	tegra_cpuidle_pcie_irqs_in_use();
 
 	return 0;
 }
 
-static const struct irq_domain_ops msi_domain_ops = {
-	.map = tegra_msi_map,
+static void tegra_msi_domain_free(struct irq_domain *domain, unsigned int virq,
+				  unsigned int nr_irqs)
+{
+	struct irq_data *d = irq_domain_get_irq_data(domain, virq);
+	struct tegra_msi *msi = domain->host_data;
+
+	mutex_lock(&msi->map_lock);
+
+	bitmap_release_region(msi->used, d->hwirq, order_base_2(nr_irqs));
+
+	mutex_unlock(&msi->map_lock);
+}
+
+static const struct irq_domain_ops tegra_msi_domain_ops = {
+	.alloc = tegra_msi_domain_alloc,
+	.free = tegra_msi_domain_free,
+};
+
+static struct msi_domain_info tegra_msi_info = {
+	.flags	= (MSI_FLAG_USE_DEF_DOM_OPS | MSI_FLAG_USE_DEF_CHIP_OPS |
+		   MSI_FLAG_PCI_MSIX),
+	.chip	= &tegra_msi_top_chip,
 };
 
+static int tegra_allocate_domains(struct tegra_msi *msi)
+{
+	struct tegra_pcie *pcie = msi_to_pcie(msi);
+	struct fwnode_handle *fwnode = dev_fwnode(pcie->dev);
+	struct irq_domain *parent;
+
+	parent = irq_domain_create_linear(fwnode, INT_PCI_MSI_NR,
+					  &tegra_msi_domain_ops, msi);
+	if (!parent) {
+		dev_err(pcie->dev, "failed to create IRQ domain\n");
+		return -ENOMEM;
+	}
+	irq_domain_update_bus_token(parent, DOMAIN_BUS_NEXUS);
+
+	msi->domain = pci_msi_create_irq_domain(fwnode, &tegra_msi_info, parent);
+	if (!msi->domain) {
+		dev_err(pcie->dev, "failed to create MSI domain\n");
+		irq_domain_remove(parent);
+		return -ENOMEM;
+	}
+
+	return 0;
+}
+
+static void tegra_free_domains(struct tegra_msi *msi)
+{
+	struct irq_domain *parent = msi->domain->parent;
+
+	irq_domain_remove(msi->domain);
+	irq_domain_remove(parent);
+}
+
 static int tegra_pcie_msi_setup(struct tegra_pcie *pcie)
 {
-	struct pci_host_bridge *host = pci_host_bridge_from_priv(pcie);
 	struct platform_device *pdev = to_platform_device(pcie->dev);
 	struct tegra_msi *msi = &pcie->msi;
 	struct device *dev = pcie->dev;
 	int err;
 
-	mutex_init(&msi->lock);
-
-	msi->chip.dev = dev;
-	msi->chip.setup_irq = tegra_msi_setup_irq;
-	msi->chip.teardown_irq = tegra_msi_teardown_irq;
+	mutex_init(&msi->map_lock);
+	spin_lock_init(&msi->mask_lock);
 
-	msi->domain = irq_domain_add_linear(dev->of_node, INT_PCI_MSI_NR,
-					    &msi_domain_ops, &msi->chip);
-	if (!msi->domain) {
-		dev_err(dev, "failed to create IRQ domain\n");
-		return -ENOMEM;
+	if (IS_ENABLED(CONFIG_PCI_MSI)) {
+		err = tegra_allocate_domains(msi);
+		if (err)
+			return err;
 	}
 
 	err = platform_get_irq_byname(pdev, "msi");

@@ -1714,12 +1766,7 @@ static int tegra_pcie_msi_setup(struct tegra_pcie *pcie)
 
 	msi->irq = err;
 
-	err = request_irq(msi->irq, tegra_pcie_msi_irq, IRQF_NO_THREAD,
-			  tegra_msi_irq_chip.name, pcie);
-	if (err < 0) {
-		dev_err(dev, "failed to request IRQ: %d\n", err);
-		goto free_irq_domain;
-	}
+	irq_set_chained_handler_and_data(msi->irq, tegra_pcie_msi_irq, pcie);
 
 	/* Though the PCIe controller can address >32-bit address space, to
 	 * facilitate endpoints that support only 32-bit MSI target address,

@@ -1740,14 +1787,14 @@ static int tegra_pcie_msi_setup(struct tegra_pcie *pcie)
 		goto free_irq;
 	}
 
-	host->msi = &msi->chip;
-
 	return 0;
 
 free_irq:
-	free_irq(msi->irq, pcie);
+	irq_set_chained_handler_and_data(msi->irq, NULL, NULL);
 free_irq_domain:
-	irq_domain_remove(msi->domain);
+	if (IS_ENABLED(CONFIG_PCI_MSI))
+		tegra_free_domains(msi);
+
 	return err;
 }
 

@@ -1762,16 +1809,6 @@ static void tegra_pcie_enable_msi(struct tegra_pcie *pcie)
 	/* this register is in 4K increments */
 	afi_writel(pcie, 1, AFI_MSI_BAR_SZ);
 
-	/* enable all MSI vectors */
-	afi_writel(pcie, 0xffffffff, AFI_MSI_EN_VEC0);
-	afi_writel(pcie, 0xffffffff, AFI_MSI_EN_VEC1);
-	afi_writel(pcie, 0xffffffff, AFI_MSI_EN_VEC2);
-	afi_writel(pcie, 0xffffffff, AFI_MSI_EN_VEC3);
-	afi_writel(pcie, 0xffffffff, AFI_MSI_EN_VEC4);
-	afi_writel(pcie, 0xffffffff, AFI_MSI_EN_VEC5);
-	afi_writel(pcie, 0xffffffff, AFI_MSI_EN_VEC6);
-	afi_writel(pcie, 0xffffffff, AFI_MSI_EN_VEC7);
-
 	/* and unmask the MSI interrupt */
 	reg = afi_readl(pcie, AFI_INTR_MASK);
 	reg |= AFI_INTR_MASK_MSI_MASK;

@@ -1786,16 +1823,16 @@ static void tegra_pcie_msi_teardown(struct tegra_pcie *pcie)
 	dma_free_attrs(pcie->dev, PAGE_SIZE, msi->virt, msi->phys,
 		       DMA_ATTR_NO_KERNEL_MAPPING);
 
-	if (msi->irq > 0)
-		free_irq(msi->irq, pcie);
-
 	for (i = 0; i < INT_PCI_MSI_NR; i++) {
 		irq = irq_find_mapping(msi->domain, i);
 		if (irq > 0)
-			irq_dispose_mapping(irq);
+			irq_domain_free_irqs(irq, 1);
 	}
 
-	irq_domain_remove(msi->domain);
+	irq_set_chained_handler_and_data(msi->irq, NULL, NULL);
+
+	if (IS_ENABLED(CONFIG_PCI_MSI))
+		tegra_free_domains(msi);
 }
 
 static int tegra_pcie_disable_msi(struct tegra_pcie *pcie)

@@ -1807,16 +1844,6 @@ static int tegra_pcie_disable_msi(struct tegra_pcie *pcie)
 	value &= ~AFI_INTR_MASK_MSI_MASK;
 	afi_writel(pcie, value, AFI_INTR_MASK);
 
-	/* disable all MSI vectors */
-	afi_writel(pcie, 0, AFI_MSI_EN_VEC0);
-	afi_writel(pcie, 0, AFI_MSI_EN_VEC1);
-	afi_writel(pcie, 0, AFI_MSI_EN_VEC2);
-	afi_writel(pcie, 0, AFI_MSI_EN_VEC3);
-	afi_writel(pcie, 0, AFI_MSI_EN_VEC4);
-	afi_writel(pcie, 0, AFI_MSI_EN_VEC5);
-	afi_writel(pcie, 0, AFI_MSI_EN_VEC6);
-	afi_writel(pcie, 0, AFI_MSI_EN_VEC7);
-
 	return 0;
 }
 

@@ -94,7 +94,6 @@
  * struct xilinx_pcie_port - PCIe port information
  * @reg_base: IO Mapped Register Base
  * @irq: Interrupt number
- * @msi_pages: MSI pages
  * @dev: Device pointer
  * @msi_domain: MSI IRQ domain pointer
  * @leg_domain: Legacy IRQ domain pointer

@@ -103,7 +102,6 @@
 struct xilinx_pcie_port {
 	void __iomem *reg_base;
 	u32 irq;
-	unsigned long msi_pages;
 	struct device *dev;
 	struct irq_domain *msi_domain;
 	struct irq_domain *leg_domain;

@@ -274,10 +272,10 @@ static int xilinx_pcie_msi_setup_irq(struct msi_controller *chip,
 
 	irq_set_msi_desc(irq, desc);
 
-	msg_addr = virt_to_phys((void *)port->msi_pages);
+	msg_addr = ALIGN_DOWN(virt_to_phys(port), SZ_4K);
 
-	msg.address_hi = 0;
-	msg.address_lo = msg_addr;
+	msg.address_hi = upper_32_bits(msg_addr);
+	msg.address_lo = lower_32_bits(msg_addr);
 	msg.data = irq;
 
 	pci_write_msi_msg(irq, &msg);

@@ -330,13 +328,9 @@ static int xilinx_pcie_enable_msi(struct xilinx_pcie_port *port)
 {
 	phys_addr_t msg_addr;
 
-	port->msi_pages = __get_free_pages(GFP_KERNEL, 0);
-	if (!port->msi_pages)
-		return -ENOMEM;
-
-	msg_addr = virt_to_phys((void *)port->msi_pages);
-	pcie_write(port, 0x0, XILINX_PCIE_REG_MSIBASE1);
-	pcie_write(port, msg_addr, XILINX_PCIE_REG_MSIBASE2);
+	msg_addr = ALIGN_DOWN(virt_to_phys(port), SZ_4K);
+	pcie_write(port, upper_32_bits(msg_addr), XILINX_PCIE_REG_MSIBASE1);
+	pcie_write(port, lower_32_bits(msg_addr), XILINX_PCIE_REG_MSIBASE2);
 
 	return 0;
 }

@@ -64,39 +64,18 @@ static void pci_msi_teardown_msi_irqs(struct pci_dev *dev)
 /* Arch hooks */
 int __weak arch_setup_msi_irq(struct pci_dev *dev, struct msi_desc *desc)
 {
-	struct msi_controller *chip = dev->bus->msi;
-	int err;
-
-	if (!chip || !chip->setup_irq)
-		return -EINVAL;
-
-	err = chip->setup_irq(chip, dev, desc);
-	if (err < 0)
-		return err;
-
-	irq_set_chip_data(desc->irq, chip);
-
-	return 0;
+	return -EINVAL;
 }
 
 void __weak arch_teardown_msi_irq(unsigned int irq)
 {
-	struct msi_controller *chip = irq_get_chip_data(irq);
-
-	if (!chip || !chip->teardown_irq)
-		return;
-
-	chip->teardown_irq(chip, irq);
 }
 
 int __weak arch_setup_msi_irqs(struct pci_dev *dev, int nvec, int type)
 {
-	struct msi_controller *chip = dev->bus->msi;
 	struct msi_desc *entry;
 	int ret;
 
-	if (chip && chip->setup_irqs)
-		return chip->setup_irqs(chip, dev, nvec, type);
 	/*
 	 * If an architecture wants to support multiple MSI, it needs to
 	 * override arch_setup_msi_irqs()

@@ -895,7 +895,6 @@ static int pci_register_host_bridge(struct pci_host_bridge *bridge)
 	/* Temporarily move resources off the list */
 	list_splice_init(&bridge->windows, &resources);
 	bus->sysdata = bridge->sysdata;
-	bus->msi = bridge->msi;
 	bus->ops = bridge->ops;
 	bus->number = bus->busn_res.start = bridge->busnr;
 #ifdef CONFIG_PCI_DOMAINS_GENERIC

@@ -1053,7 +1052,6 @@ static struct pci_bus *pci_alloc_child_bus(struct pci_bus *parent,
 		return NULL;
 
 	child->parent = parent;
-	child->msi = parent->msi;
 	child->sysdata = parent->sysdata;
 	child->bus_flags = parent->bus_flags;
 

@@ -540,7 +540,6 @@ struct pci_host_bridge {
 	int (*map_irq)(const struct pci_dev *, u8, u8);
 	void (*release_fn)(struct pci_host_bridge *);
 	void		*release_data;
-	struct msi_controller *msi;
 	unsigned int	ignore_reset_delay:1;	/* For entire hierarchy */
 	unsigned int	no_ext_tags:1;		/* No Extended Tags */
 	unsigned int	native_aer:1;		/* OS may use PCIe AER */

@@ -621,7 +620,6 @@ struct pci_bus {
 	struct resource busn_res;	/* Bus numbers routed to this bus */
 
 	struct pci_ops	*ops;		/* Configuration access functions */
-	struct msi_controller *msi;	/* MSI controller */
 	void		*sysdata;	/* Hook for sys-specific extension */
 	struct proc_dir_entry *procdir;	/* Directory entry in /proc/bus/pci */
 

@@ -36,7 +36,6 @@ struct rcar_msi {
 	DECLARE_BITMAP(used, INT_PCI_MSI_NR);
 	struct irq_domain *domain;
 	struct msi_controller chip;
-	unsigned long pages;
 	struct mutex lock;
 	int irq1;
 	int irq2;

@@ -680,14 +679,15 @@ static void rcar_pcie_unmap_msi(struct rcar_pcie_host *host)
 static void rcar_pcie_hw_enable_msi(struct rcar_pcie_host *host)
 {
 	struct rcar_pcie *pcie = &host->pcie;
-	struct rcar_msi *msi = &host->msi;
-	unsigned long base;
+	struct device *dev = pcie->dev;
+	struct resource res;
 
-	/* setup MSI data target */
-	base = virt_to_phys((void *)msi->pages);
+	if (WARN_ON(of_address_to_resource(dev->of_node, 0, &res)))
+		return;
 
-	rcar_pci_write_reg(pcie, lower_32_bits(base) | MSIFE, PCIEMSIALR);
-	rcar_pci_write_reg(pcie, upper_32_bits(base), PCIEMSIAUR);
+	/* setup MSI data target */
+	rcar_pci_write_reg(pcie, lower_32_bits(res.start) | MSIFE, PCIEMSIALR);
+	rcar_pci_write_reg(pcie, upper_32_bits(res.start), PCIEMSIAUR);
 
 	/* enable all MSI interrupts */
 	rcar_pci_write_reg(pcie, 0xffffffff, PCIEMSIIER);

@@ -735,7 +735,6 @@ static int rcar_pcie_enable_msi(struct rcar_pcie_host *host)
 	}
 
 	/* setup MSI data target */
-	msi->pages = __get_free_pages(GFP_KERNEL | GFP_DMA32, 0);
 	rcar_pcie_hw_enable_msi(host);
 
 	return 0;

@@ -748,7 +747,6 @@ static int rcar_pcie_enable_msi(struct rcar_pcie_host *host)
 static void rcar_pcie_teardown_msi(struct rcar_pcie_host *host)
 {
 	struct rcar_pcie *pcie = &host->pcie;
-	struct rcar_msi *msi = &host->msi;
 
 	/* Disable all MSI interrupts */
 	rcar_pci_write_reg(pcie, 0, PCIEMSIIER);

@@ -756,8 +754,6 @@ static void rcar_pcie_teardown_msi(struct rcar_pcie_host *host)
 	/* Disable address decoding of the MSI interrupt, MSIFE */
 	rcar_pci_write_reg(pcie, 0, PCIEMSIALR);
 
-	free_pages(msi->pages, 0);
-
 	rcar_pcie_unmap_msi(host);
 }
 

@@ -473,7 +473,6 @@ struct hv_pcibus_device {
 	struct list_head dr_list;
 
 	struct msi_domain_info msi_info;
-	struct msi_controller msi_chip;
 	struct irq_domain *irq_domain;
 
 	spinlock_t retarget_msi_interrupt_lock;

@@ -1866,9 +1865,6 @@ static int create_root_hv_pci_bus(struct hv_pcibus_device *hbus)
 	if (!hbus->pci_bus)
 		return -ENODEV;
 
-	hbus->pci_bus->msi = &hbus->msi_chip;
-	hbus->pci_bus->msi->dev = &hbus->hdev->device;
-
 	pci_lock_rescan_remove();
 	pci_scan_child_bus(hbus->pci_bus);
 	hv_pci_assign_numa_node(hbus);

@@ -86,7 +86,7 @@ config PCI_HOST_GENERIC
 config PCIE_XILINX
 	bool "Xilinx AXI PCIe host bridge support"
 	depends on OF || COMPILE_TEST
-	select PCI_MSI_ARCH_FALLBACKS
+	depends on PCI_MSI_IRQ_DOMAIN
 	help
 	  Say 'Y' here if you want kernel to support the Xilinx AXI PCIe
 	  Host Bridge driver.

@@ -93,23 +93,23 @@
 /**
  * struct xilinx_pcie_port - PCIe port information
  * @reg_base: IO Mapped Register Base
- * @irq: Interrupt number
  * @dev: Device pointer
+ * @msi_map: Bitmap of allocated MSIs
+ * @map_lock: Mutex protecting the MSI allocation
  * @msi_domain: MSI IRQ domain pointer
  * @leg_domain: Legacy IRQ domain pointer
  * @resources: Bus Resources
  */
 struct xilinx_pcie_port {
 	void __iomem *reg_base;
-	u32 irq;
 	struct device *dev;
+	unsigned long msi_map[BITS_TO_LONGS(XILINX_NUM_MSI_IRQS)];
+	struct mutex map_lock;
 	struct irq_domain *msi_domain;
 	struct irq_domain *leg_domain;
 	struct list_head resources;
 };
 
-static DECLARE_BITMAP(msi_irq_in_use, XILINX_NUM_MSI_IRQS);
-
 static inline u32 pcie_read(struct xilinx_pcie_port *port, u32 reg)
 {
 	return readl(port->reg_base + reg);

@@ -194,145 +194,116 @@ static struct pci_ops xilinx_pcie_ops = {
 
 /* MSI functions */
 
-/**
- * xilinx_pcie_destroy_msi - Free MSI number
- * @irq: IRQ to be freed
- */
-static void xilinx_pcie_destroy_msi(unsigned int irq)
+static void xilinx_msi_top_irq_ack(struct irq_data *d)
 {
-	struct msi_desc *msi;
-	struct xilinx_pcie_port *port;
-	struct irq_data *d = irq_get_irq_data(irq);
-	irq_hw_number_t hwirq = irqd_to_hwirq(d);
-
-	if (!test_bit(hwirq, msi_irq_in_use)) {
-		msi = irq_get_msi_desc(irq);
-		port = msi_desc_to_pci_sysdata(msi);
-		dev_err(port->dev, "Trying to free unused MSI#%d\n", irq);
-	} else {
-		clear_bit(hwirq, msi_irq_in_use);
-	}
+	/*
+	 * xilinx_pcie_intr_handler() will have performed the Ack.
+	 * Eventually, this should be fixed and the Ack be moved in
+	 * the respective callbacks for INTx and MSI.
+	 */
 }
 
-/**
- * xilinx_pcie_assign_msi - Allocate MSI number
- *
- * Return: A valid IRQ on success and error value on failure.
- */
-static int xilinx_pcie_assign_msi(void)
-{
-	int pos;
-
-	pos = find_first_zero_bit(msi_irq_in_use, XILINX_NUM_MSI_IRQS);
-	if (pos < XILINX_NUM_MSI_IRQS)
-		set_bit(pos, msi_irq_in_use);
-	else
-		return -ENOSPC;
+static struct irq_chip xilinx_msi_top_chip = {
+	.name		= "PCIe MSI",
+	.irq_ack	= xilinx_msi_top_irq_ack,
+};
 
-	return pos;
+static int xilinx_msi_set_affinity(struct irq_data *d, const struct cpumask *mask, bool force)
+{
+	return -EINVAL;
 }
 
-/**
- * xilinx_msi_teardown_irq - Destroy the MSI
- * @chip: MSI Chip descriptor
- * @irq: MSI IRQ to destroy
- */
-static void xilinx_msi_teardown_irq(struct msi_controller *chip,
-				    unsigned int irq)
+static void xilinx_compose_msi_msg(struct irq_data *data, struct msi_msg *msg)
 {
-	xilinx_pcie_destroy_msi(irq);
-	irq_dispose_mapping(irq);
+	struct xilinx_pcie_port *pcie = irq_data_get_irq_chip_data(data);
+	phys_addr_t pa = ALIGN_DOWN(virt_to_phys(pcie), SZ_4K);
+
+	msg->address_lo = lower_32_bits(pa);
+	msg->address_hi = upper_32_bits(pa);
+	msg->data = data->hwirq;
 }
 
-/**
- * xilinx_pcie_msi_setup_irq - Setup MSI request
- * @chip: MSI chip pointer
- * @pdev: PCIe device pointer
- * @desc: MSI descriptor pointer
- *
- * Return: '0' on success and error value on failure
- */
-static int xilinx_pcie_msi_setup_irq(struct msi_controller *chip,
-				     struct pci_dev *pdev,
-				     struct msi_desc *desc)
+static struct irq_chip xilinx_msi_bottom_chip = {
+	.name			= "Xilinx MSI",
+	.irq_set_affinity 	= xilinx_msi_set_affinity,
+	.irq_compose_msi_msg	= xilinx_compose_msi_msg,
+};
+
+static int xilinx_msi_domain_alloc(struct irq_domain *domain, unsigned int virq,
+				  unsigned int nr_irqs, void *args)
 {
-	struct xilinx_pcie_port *port = pdev->bus->sysdata;
-	unsigned int irq;
-	int hwirq;
-	struct msi_msg msg;
-	phys_addr_t msg_addr;
+	struct xilinx_pcie_port *port = domain->host_data;
+	int hwirq, i;
+
+	mutex_lock(&port->map_lock);
+
+	hwirq = bitmap_find_free_region(port->msi_map, XILINX_NUM_MSI_IRQS, order_base_2(nr_irqs));
+
+	mutex_unlock(&port->map_lock);
 
-	hwirq = xilinx_pcie_assign_msi();
 	if (hwirq < 0)
-		return hwirq;
+		return -ENOSPC;
 
-	irq = irq_create_mapping(port->msi_domain, hwirq);
-	if (!irq)
-		return -EINVAL;
+	for (i = 0; i < nr_irqs; i++)
+		irq_domain_set_info(domain, virq + i, hwirq + i,
+				    &xilinx_msi_bottom_chip, domain->host_data,
+				    handle_edge_irq, NULL, NULL);
 
-	irq_set_msi_desc(irq, desc);
+	return 0;
+}
 
-	msg_addr = ALIGN_DOWN(virt_to_phys(port), SZ_4K);
+static void xilinx_msi_domain_free(struct irq_domain *domain, unsigned int virq,
+				  unsigned int nr_irqs)
+{
+	struct irq_data *d = irq_domain_get_irq_data(domain, virq);
+	struct xilinx_pcie_port *port = domain->host_data;
 
-	msg.address_hi = upper_32_bits(msg_addr);
-	msg.address_lo = lower_32_bits(msg_addr);
-	msg.data = irq;
+	mutex_lock(&port->map_lock);
 
-	pci_write_msi_msg(irq, &msg);
+	bitmap_release_region(port->msi_map, d->hwirq, order_base_2(nr_irqs));
 
-	return 0;
+	mutex_unlock(&port->map_lock);
 }
 
-/* MSI Chip Descriptor */
-static struct msi_controller xilinx_pcie_msi_chip = {
-	.setup_irq = xilinx_pcie_msi_setup_irq,
-	.teardown_irq = xilinx_msi_teardown_irq,
+static const struct irq_domain_ops xilinx_msi_domain_ops = {
+	.alloc	= xilinx_msi_domain_alloc,
+	.free	= xilinx_msi_domain_free,
 };
 
-/* HW Interrupt Chip Descriptor */
-static struct irq_chip xilinx_msi_irq_chip = {
-	.name = "Xilinx PCIe MSI",
-	.irq_enable = pci_msi_unmask_irq,
-	.irq_disable = pci_msi_mask_irq,
-	.irq_mask = pci_msi_mask_irq,
-	.irq_unmask = pci_msi_unmask_irq,
+static struct msi_domain_info xilinx_msi_info = {
+	.flags	= (MSI_FLAG_USE_DEF_DOM_OPS | MSI_FLAG_USE_DEF_CHIP_OPS),
+	.chip	= &xilinx_msi_top_chip,
 };
 
-/**
- * xilinx_pcie_msi_map - Set the handler for the MSI and mark IRQ as valid
- * @domain: IRQ domain
- * @irq: Virtual IRQ number
- * @hwirq: HW interrupt number
- *
- * Return: Always returns 0.
- */
-static int xilinx_pcie_msi_map(struct irq_domain *domain, unsigned int irq,
-			       irq_hw_number_t hwirq)
+static int xilinx_allocate_msi_domains(struct xilinx_pcie_port *pcie)
 {
-	irq_set_chip_and_handler(irq, &xilinx_msi_irq_chip, handle_simple_irq);
-	irq_set_chip_data(irq, domain->host_data);
+	struct fwnode_handle *fwnode = dev_fwnode(pcie->dev);
+	struct irq_domain *parent;
+
+	parent = irq_domain_create_linear(fwnode, XILINX_NUM_MSI_IRQS,
+					  &xilinx_msi_domain_ops, pcie);
+	if (!parent) {
+		dev_err(pcie->dev, "failed to create IRQ domain\n");
+		return -ENOMEM;
+	}
+	irq_domain_update_bus_token(parent, DOMAIN_BUS_NEXUS);
+
+	pcie->msi_domain = pci_msi_create_irq_domain(fwnode, &xilinx_msi_info, parent);
+	if (!pcie->msi_domain) {
+		dev_err(pcie->dev, "failed to create MSI domain\n");
+		irq_domain_remove(parent);
+		return -ENOMEM;
+	}
 
 	return 0;
 }
 
-/* IRQ Domain operations */
-static const struct irq_domain_ops msi_domain_ops = {
-	.map = xilinx_pcie_msi_map,
-};
-
-/**
- * xilinx_pcie_enable_msi - Enable MSI support
- * @port: PCIe port information
- */
-static int xilinx_pcie_enable_msi(struct xilinx_pcie_port *port)
+static void xilinx_free_msi_domains(struct xilinx_pcie_port *pcie)
 {
-	phys_addr_t msg_addr;
-
-	msg_addr = ALIGN_DOWN(virt_to_phys(port), SZ_4K);
-	pcie_write(port, upper_32_bits(msg_addr), XILINX_PCIE_REG_MSIBASE1);
-	pcie_write(port, lower_32_bits(msg_addr), XILINX_PCIE_REG_MSIBASE2);
+	struct irq_domain *parent = pcie->msi_domain->parent;
 
-	return 0;
+	irq_domain_remove(pcie->msi_domain);
+	irq_domain_remove(parent);
 }
 
 /* INTx Functions */