Adding upstream version 4.19.249.upstream/4.19.249upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 683 insertions, 0 deletions

diff --git a/drivers/pci/controller/pcie-iproc-msi.c b/drivers/pci/controller/pcie-iproc-msi.c
new file mode 100644
index 000000000..dc4d5a590
--- /dev/null
+++ b/drivers/pci/controller/pcie-iproc-msi.c
@@ -0,0 +1,683 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2015 Broadcom Corporation
+ */
+
+#include <linux/interrupt.h>
+#include <linux/irqchip/chained_irq.h>
+#include <linux/irqdomain.h>
+#include <linux/msi.h>
+#include <linux/of_irq.h>
+#include <linux/of_pci.h>
+#include <linux/pci.h>
+
+#include "pcie-iproc.h"
+
+#define IPROC_MSI_INTR_EN_SHIFT        11
+#define IPROC_MSI_INTR_EN              BIT(IPROC_MSI_INTR_EN_SHIFT)
+#define IPROC_MSI_INT_N_EVENT_SHIFT    1
+#define IPROC_MSI_INT_N_EVENT          BIT(IPROC_MSI_INT_N_EVENT_SHIFT)
+#define IPROC_MSI_EQ_EN_SHIFT          0
+#define IPROC_MSI_EQ_EN                BIT(IPROC_MSI_EQ_EN_SHIFT)
+
+#define IPROC_MSI_EQ_MASK              0x3f
+
+/* Max number of GIC interrupts */
+#define NR_HW_IRQS                     6
+
+/* Number of entries in each event queue */
+#define EQ_LEN                         64
+
+/* Size of each event queue memory region */
+#define EQ_MEM_REGION_SIZE             SZ_4K
+
+/* Size of each MSI address region */
+#define MSI_MEM_REGION_SIZE            SZ_4K
+
+enum iproc_msi_reg {
+	IPROC_MSI_EQ_PAGE = 0,
+	IPROC_MSI_EQ_PAGE_UPPER,
+	IPROC_MSI_PAGE,
+	IPROC_MSI_PAGE_UPPER,
+	IPROC_MSI_CTRL,
+	IPROC_MSI_EQ_HEAD,
+	IPROC_MSI_EQ_TAIL,
+	IPROC_MSI_INTS_EN,
+	IPROC_MSI_REG_SIZE,
+};
+
+struct iproc_msi;
+
+/**
+ * iProc MSI group
+ *
+ * One MSI group is allocated per GIC interrupt, serviced by one iProc MSI
+ * event queue.
+ *
+ * @msi: pointer to iProc MSI data
+ * @gic_irq: GIC interrupt
+ * @eq: Event queue number
+ */
+struct iproc_msi_grp {
+	struct iproc_msi *msi;
+	int gic_irq;
+	unsigned int eq;
+};
+
+/**
+ * iProc event queue based MSI
+ *
+ * Only meant to be used on platforms without MSI support integrated into the
+ * GIC.
+ *
+ * @pcie: pointer to iProc PCIe data
+ * @reg_offsets: MSI register offsets
+ * @grps: MSI groups
+ * @nr_irqs: number of total interrupts connected to GIC
+ * @nr_cpus: number of toal CPUs
+ * @has_inten_reg: indicates the MSI interrupt enable register needs to be
+ * set explicitly (required for some legacy platforms)
+ * @bitmap: MSI vector bitmap
+ * @bitmap_lock: lock to protect access to the MSI bitmap
+ * @nr_msi_vecs: total number of MSI vectors
+ * @inner_domain: inner IRQ domain
+ * @msi_domain: MSI IRQ domain
+ * @nr_eq_region: required number of 4K aligned memory region for MSI event
+ * queues
+ * @nr_msi_region: required number of 4K aligned address region for MSI posted
+ * writes
+ * @eq_cpu: pointer to allocated memory region for MSI event queues
+ * @eq_dma: DMA address of MSI event queues
+ * @msi_addr: MSI address
+ */
+struct iproc_msi {
+	struct iproc_pcie *pcie;
+	const u16 (*reg_offsets)[IPROC_MSI_REG_SIZE];
+	struct iproc_msi_grp *grps;
+	int nr_irqs;
+	int nr_cpus;
+	bool has_inten_reg;
+	unsigned long *bitmap;
+	struct mutex bitmap_lock;
+	unsigned int nr_msi_vecs;
+	struct irq_domain *inner_domain;
+	struct irq_domain *msi_domain;
+	unsigned int nr_eq_region;
+	unsigned int nr_msi_region;
+	void *eq_cpu;
+	dma_addr_t eq_dma;
+	phys_addr_t msi_addr;
+};
+
+static const u16 iproc_msi_reg_paxb[NR_HW_IRQS][IPROC_MSI_REG_SIZE] = {
+	{ 0x200, 0x2c0, 0x204, 0x2c4, 0x210, 0x250, 0x254, 0x208 },
+	{ 0x200, 0x2c0, 0x204, 0x2c4, 0x214, 0x258, 0x25c, 0x208 },
+	{ 0x200, 0x2c0, 0x204, 0x2c4, 0x218, 0x260, 0x264, 0x208 },
+	{ 0x200, 0x2c0, 0x204, 0x2c4, 0x21c, 0x268, 0x26c, 0x208 },
+	{ 0x200, 0x2c0, 0x204, 0x2c4, 0x220, 0x270, 0x274, 0x208 },
+	{ 0x200, 0x2c0, 0x204, 0x2c4, 0x224, 0x278, 0x27c, 0x208 },
+};
+
+static const u16 iproc_msi_reg_paxc[NR_HW_IRQS][IPROC_MSI_REG_SIZE] = {
+	{ 0xc00, 0xc04, 0xc08, 0xc0c, 0xc40, 0xc50, 0xc60 },
+	{ 0xc10, 0xc14, 0xc18, 0xc1c, 0xc44, 0xc54, 0xc64 },
+	{ 0xc20, 0xc24, 0xc28, 0xc2c, 0xc48, 0xc58, 0xc68 },
+	{ 0xc30, 0xc34, 0xc38, 0xc3c, 0xc4c, 0xc5c, 0xc6c },
+};
+
+static inline u32 iproc_msi_read_reg(struct iproc_msi *msi,
+				     enum iproc_msi_reg reg,
+				     unsigned int eq)
+{
+	struct iproc_pcie *pcie = msi->pcie;
+
+	return readl_relaxed(pcie->base + msi->reg_offsets[eq][reg]);
+}
+
+static inline void iproc_msi_write_reg(struct iproc_msi *msi,
+				       enum iproc_msi_reg reg,
+				       int eq, u32 val)
+{
+	struct iproc_pcie *pcie = msi->pcie;
+
+	writel_relaxed(val, pcie->base + msi->reg_offsets[eq][reg]);
+}
+
+static inline u32 hwirq_to_group(struct iproc_msi *msi, unsigned long hwirq)
+{
+	return (hwirq % msi->nr_irqs);
+}
+
+static inline unsigned int iproc_msi_addr_offset(struct iproc_msi *msi,
+						 unsigned long hwirq)
+{
+	if (msi->nr_msi_region > 1)
+		return hwirq_to_group(msi, hwirq) * MSI_MEM_REGION_SIZE;
+	else
+		return hwirq_to_group(msi, hwirq) * sizeof(u32);
+}
+
+static inline unsigned int iproc_msi_eq_offset(struct iproc_msi *msi, u32 eq)
+{
+	if (msi->nr_eq_region > 1)
+		return eq * EQ_MEM_REGION_SIZE;
+	else
+		return eq * EQ_LEN * sizeof(u32);
+}
+
+static struct irq_chip iproc_msi_irq_chip = {
+	.name = "iProc-MSI",
+};
+
+static struct msi_domain_info iproc_msi_domain_info = {
+	.flags = MSI_FLAG_USE_DEF_DOM_OPS | MSI_FLAG_USE_DEF_CHIP_OPS |
+		MSI_FLAG_PCI_MSIX,
+	.chip = &iproc_msi_irq_chip,
+};
+
+/*
+ * In iProc PCIe core, each MSI group is serviced by a GIC interrupt and a
+ * dedicated event queue.  Each MSI group can support up to 64 MSI vectors.
+ *
+ * The number of MSI groups varies between different iProc SoCs.  The total
+ * number of CPU cores also varies.  To support MSI IRQ affinity, we
+ * distribute GIC interrupts across all available CPUs.  MSI vector is moved
+ * from one GIC interrupt to another to steer to the target CPU.
+ *
+ * Assuming:
+ * - the number of MSI groups is M
+ * - the number of CPU cores is N
+ * - M is always a multiple of N
+ *
+ * Total number of raw MSI vectors = M * 64
+ * Total number of supported MSI vectors = (M * 64) / N
+ */
+static inline int hwirq_to_cpu(struct iproc_msi *msi, unsigned long hwirq)
+{
+	return (hwirq % msi->nr_cpus);
+}
+
+static inline unsigned long hwirq_to_canonical_hwirq(struct iproc_msi *msi,
+						     unsigned long hwirq)
+{
+	return (hwirq - hwirq_to_cpu(msi, hwirq));
+}
+
+static int iproc_msi_irq_set_affinity(struct irq_data *data,
+				      const struct cpumask *mask, bool force)
+{
+	struct iproc_msi *msi = irq_data_get_irq_chip_data(data);
+	int target_cpu = cpumask_first(mask);
+	int curr_cpu;
+	int ret;
+
+	curr_cpu = hwirq_to_cpu(msi, data->hwirq);
+	if (curr_cpu == target_cpu)
+		ret = IRQ_SET_MASK_OK_DONE;
+	else {
+		/* steer MSI to the target CPU */
+		data->hwirq = hwirq_to_canonical_hwirq(msi, data->hwirq) + target_cpu;
+		ret = IRQ_SET_MASK_OK;
+	}
+
+	irq_data_update_effective_affinity(data, cpumask_of(target_cpu));
+
+	return ret;
+}
+
+static void iproc_msi_irq_compose_msi_msg(struct irq_data *data,
+					  struct msi_msg *msg)
+{
+	struct iproc_msi *msi = irq_data_get_irq_chip_data(data);
+	dma_addr_t addr;
+
+	addr = msi->msi_addr + iproc_msi_addr_offset(msi, data->hwirq);
+	msg->address_lo = lower_32_bits(addr);
+	msg->address_hi = upper_32_bits(addr);
+	msg->data = data->hwirq << 5;
+}
+
+static struct irq_chip iproc_msi_bottom_irq_chip = {
+	.name = "MSI",
+	.irq_set_affinity = iproc_msi_irq_set_affinity,
+	.irq_compose_msi_msg = iproc_msi_irq_compose_msi_msg,
+};
+
+static int iproc_msi_irq_domain_alloc(struct irq_domain *domain,
+				      unsigned int virq, unsigned int nr_irqs,
+				      void *args)
+{
+	struct iproc_msi *msi = domain->host_data;
+	int hwirq, i;
+
+	if (msi->nr_cpus > 1 && nr_irqs > 1)
+		return -EINVAL;
+
+	mutex_lock(&msi->bitmap_lock);
+
+	/*
+	 * Allocate 'nr_irqs' multiplied by 'nr_cpus' number of MSI vectors
+	 * each time
+	 */
+	hwirq = bitmap_find_free_region(msi->bitmap, msi->nr_msi_vecs,
+					order_base_2(msi->nr_cpus * nr_irqs));
+
+	mutex_unlock(&msi->bitmap_lock);
+
+	if (hwirq < 0)
+		return -ENOSPC;
+
+	for (i = 0; i < nr_irqs; i++) {
+		irq_domain_set_info(domain, virq + i, hwirq + i,
+				    &iproc_msi_bottom_irq_chip,
+				    domain->host_data, handle_simple_irq,
+				    NULL, NULL);
+	}
+
+	return 0;
+}
+
+static void iproc_msi_irq_domain_free(struct irq_domain *domain,
+				      unsigned int virq, unsigned int nr_irqs)
+{
+	struct irq_data *data = irq_domain_get_irq_data(domain, virq);
+	struct iproc_msi *msi = irq_data_get_irq_chip_data(data);
+	unsigned int hwirq;
+
+	mutex_lock(&msi->bitmap_lock);
+
+	hwirq = hwirq_to_canonical_hwirq(msi, data->hwirq);
+	bitmap_release_region(msi->bitmap, hwirq,
+			      order_base_2(msi->nr_cpus * nr_irqs));
+
+	mutex_unlock(&msi->bitmap_lock);
+
+	irq_domain_free_irqs_parent(domain, virq, nr_irqs);
+}
+
+static const struct irq_domain_ops msi_domain_ops = {
+	.alloc = iproc_msi_irq_domain_alloc,
+	.free = iproc_msi_irq_domain_free,
+};
+
+static inline u32 decode_msi_hwirq(struct iproc_msi *msi, u32 eq, u32 head)
+{
+	u32 *msg, hwirq;
+	unsigned int offs;
+
+	offs = iproc_msi_eq_offset(msi, eq) + head * sizeof(u32);
+	msg = (u32 *)(msi->eq_cpu + offs);
+	hwirq = readl(msg);
+	hwirq = (hwirq >> 5) + (hwirq & 0x1f);
+
+	/*
+	 * Since we have multiple hwirq mapped to a single MSI vector,
+	 * now we need to derive the hwirq at CPU0.  It can then be used to
+	 * mapped back to virq.
+	 */
+	return hwirq_to_canonical_hwirq(msi, hwirq);
+}
+
+static void iproc_msi_handler(struct irq_desc *desc)
+{
+	struct irq_chip *chip = irq_desc_get_chip(desc);
+	struct iproc_msi_grp *grp;
+	struct iproc_msi *msi;
+	u32 eq, head, tail, nr_events;
+	unsigned long hwirq;
+	int virq;
+
+	chained_irq_enter(chip, desc);
+
+	grp = irq_desc_get_handler_data(desc);
+	msi = grp->msi;
+	eq = grp->eq;
+
+	/*
+	 * iProc MSI event queue is tracked by head and tail pointers.  Head
+	 * pointer indicates the next entry (MSI data) to be consumed by SW in
+	 * the queue and needs to be updated by SW.  iProc MSI core uses the
+	 * tail pointer as the next data insertion point.
+	 *
+	 * Entries between head and tail pointers contain valid MSI data.  MSI
+	 * data is guaranteed to be in the event queue memory before the tail
+	 * pointer is updated by the iProc MSI core.
+	 */
+	head = iproc_msi_read_reg(msi, IPROC_MSI_EQ_HEAD,
+				  eq) & IPROC_MSI_EQ_MASK;
+	do {
+		tail = iproc_msi_read_reg(msi, IPROC_MSI_EQ_TAIL,
+					  eq) & IPROC_MSI_EQ_MASK;
+
+		/*
+		 * Figure out total number of events (MSI data) to be
+		 * processed.
+		 */
+		nr_events = (tail < head) ?
+			(EQ_LEN - (head - tail)) : (tail - head);
+		if (!nr_events)
+			break;
+
+		/* process all outstanding events */
+		while (nr_events--) {
+			hwirq = decode_msi_hwirq(msi, eq, head);
+			virq = irq_find_mapping(msi->inner_domain, hwirq);
+			generic_handle_irq(virq);
+
+			head++;
+			head %= EQ_LEN;
+		}
+
+		/*
+		 * Now all outstanding events have been processed.  Update the
+		 * head pointer.
+		 */
+		iproc_msi_write_reg(msi, IPROC_MSI_EQ_HEAD, eq, head);
+
+		/*
+		 * Now go read the tail pointer again to see if there are new
+		 * oustanding events that came in during the above window.
+		 */
+	} while (true);
+
+	chained_irq_exit(chip, desc);
+}
+
+static void iproc_msi_enable(struct iproc_msi *msi)
+{
+	int i, eq;
+	u32 val;
+
+	/* Program memory region for each event queue */
+	for (i = 0; i < msi->nr_eq_region; i++) {
+		dma_addr_t addr = msi->eq_dma + (i * EQ_MEM_REGION_SIZE);
+
+		iproc_msi_write_reg(msi, IPROC_MSI_EQ_PAGE, i,
+				    lower_32_bits(addr));
+		iproc_msi_write_reg(msi, IPROC_MSI_EQ_PAGE_UPPER, i,
+				    upper_32_bits(addr));
+	}
+
+	/* Program address region for MSI posted writes */
+	for (i = 0; i < msi->nr_msi_region; i++) {
+		phys_addr_t addr = msi->msi_addr + (i * MSI_MEM_REGION_SIZE);
+
+		iproc_msi_write_reg(msi, IPROC_MSI_PAGE, i,
+				    lower_32_bits(addr));
+		iproc_msi_write_reg(msi, IPROC_MSI_PAGE_UPPER, i,
+				    upper_32_bits(addr));
+	}
+
+	for (eq = 0; eq < msi->nr_irqs; eq++) {
+		/* Enable MSI event queue */
+		val = IPROC_MSI_INTR_EN | IPROC_MSI_INT_N_EVENT |
+			IPROC_MSI_EQ_EN;
+		iproc_msi_write_reg(msi, IPROC_MSI_CTRL, eq, val);
+
+		/*
+		 * Some legacy platforms require the MSI interrupt enable
+		 * register to be set explicitly.
+		 */
+		if (msi->has_inten_reg) {
+			val = iproc_msi_read_reg(msi, IPROC_MSI_INTS_EN, eq);
+			val |= BIT(eq);
+			iproc_msi_write_reg(msi, IPROC_MSI_INTS_EN, eq, val);
+		}
+	}
+}
+
+static void iproc_msi_disable(struct iproc_msi *msi)
+{
+	u32 eq, val;
+
+	for (eq = 0; eq < msi->nr_irqs; eq++) {
+		if (msi->has_inten_reg) {
+			val = iproc_msi_read_reg(msi, IPROC_MSI_INTS_EN, eq);
+			val &= ~BIT(eq);
+			iproc_msi_write_reg(msi, IPROC_MSI_INTS_EN, eq, val);
+		}
+
+		val = iproc_msi_read_reg(msi, IPROC_MSI_CTRL, eq);
+		val &= ~(IPROC_MSI_INTR_EN | IPROC_MSI_INT_N_EVENT |
+			 IPROC_MSI_EQ_EN);
+		iproc_msi_write_reg(msi, IPROC_MSI_CTRL, eq, val);
+	}
+}
+
+static int iproc_msi_alloc_domains(struct device_node *node,
+				   struct iproc_msi *msi)
+{
+	msi->inner_domain = irq_domain_add_linear(NULL, msi->nr_msi_vecs,
+						  &msi_domain_ops, msi);
+	if (!msi->inner_domain)
+		return -ENOMEM;
+
+	msi->msi_domain = pci_msi_create_irq_domain(of_node_to_fwnode(node),
+						    &iproc_msi_domain_info,
+						    msi->inner_domain);
+	if (!msi->msi_domain) {
+		irq_domain_remove(msi->inner_domain);
+		return -ENOMEM;
+	}
+
+	return 0;
+}
+
+static void iproc_msi_free_domains(struct iproc_msi *msi)
+{
+	if (msi->msi_domain)
+		irq_domain_remove(msi->msi_domain);
+
+	if (msi->inner_domain)
+		irq_domain_remove(msi->inner_domain);
+}
+
+static void iproc_msi_irq_free(struct iproc_msi *msi, unsigned int cpu)
+{
+	int i;
+
+	for (i = cpu; i < msi->nr_irqs; i += msi->nr_cpus) {
+		irq_set_chained_handler_and_data(msi->grps[i].gic_irq,
+						 NULL, NULL);
+	}
+}
+
+static int iproc_msi_irq_setup(struct iproc_msi *msi, unsigned int cpu)
+{
+	int i, ret;
+	cpumask_var_t mask;
+	struct iproc_pcie *pcie = msi->pcie;
+
+	for (i = cpu; i < msi->nr_irqs; i += msi->nr_cpus) {
+		irq_set_chained_handler_and_data(msi->grps[i].gic_irq,
+						 iproc_msi_handler,
+						 &msi->grps[i]);
+		/* Dedicate GIC interrupt to each CPU core */
+		if (alloc_cpumask_var(&mask, GFP_KERNEL)) {
+			cpumask_clear(mask);
+			cpumask_set_cpu(cpu, mask);
+			ret = irq_set_affinity(msi->grps[i].gic_irq, mask);
+			if (ret)
+				dev_err(pcie->dev,
+					"failed to set affinity for IRQ%d\n",
+					msi->grps[i].gic_irq);
+			free_cpumask_var(mask);
+		} else {
+			dev_err(pcie->dev, "failed to alloc CPU mask\n");
+			ret = -EINVAL;
+		}
+
+		if (ret) {
+			/* Free all configured/unconfigured IRQs */
+			iproc_msi_irq_free(msi, cpu);
+			return ret;
+		}
+	}
+
+	return 0;
+}
+
+int iproc_msi_init(struct iproc_pcie *pcie, struct device_node *node)
+{
+	struct iproc_msi *msi;
+	int i, ret;
+	unsigned int cpu;
+
+	if (!of_device_is_compatible(node, "brcm,iproc-msi"))
+		return -ENODEV;
+
+	if (!of_find_property(node, "msi-controller", NULL))
+		return -ENODEV;
+
+	if (pcie->msi)
+		return -EBUSY;
+
+	msi = devm_kzalloc(pcie->dev, sizeof(*msi), GFP_KERNEL);
+	if (!msi)
+		return -ENOMEM;
+
+	msi->pcie = pcie;
+	pcie->msi = msi;
+	msi->msi_addr = pcie->base_addr;
+	mutex_init(&msi->bitmap_lock);
+	msi->nr_cpus = num_possible_cpus();
+
+	if (msi->nr_cpus == 1)
+		iproc_msi_domain_info.flags |=  MSI_FLAG_MULTI_PCI_MSI;
+
+	msi->nr_irqs = of_irq_count(node);
+	if (!msi->nr_irqs) {
+		dev_err(pcie->dev, "found no MSI GIC interrupt\n");
+		return -ENODEV;
+	}
+
+	if (msi->nr_irqs > NR_HW_IRQS) {
+		dev_warn(pcie->dev, "too many MSI GIC interrupts defined %d\n",
+			 msi->nr_irqs);
+		msi->nr_irqs = NR_HW_IRQS;
+	}
+
+	if (msi->nr_irqs < msi->nr_cpus) {
+		dev_err(pcie->dev,
+			"not enough GIC interrupts for MSI affinity\n");
+		return -EINVAL;
+	}
+
+	if (msi->nr_irqs % msi->nr_cpus != 0) {
+		msi->nr_irqs -= msi->nr_irqs % msi->nr_cpus;
+		dev_warn(pcie->dev, "Reducing number of interrupts to %d\n",
+			 msi->nr_irqs);
+	}
+
+	switch (pcie->type) {
+	case IPROC_PCIE_PAXB_BCMA:
+	case IPROC_PCIE_PAXB:
+		msi->reg_offsets = iproc_msi_reg_paxb;
+		msi->nr_eq_region = 1;
+		msi->nr_msi_region = 1;
+		break;
+	case IPROC_PCIE_PAXC:
+		msi->reg_offsets = iproc_msi_reg_paxc;
+		msi->nr_eq_region = msi->nr_irqs;
+		msi->nr_msi_region = msi->nr_irqs;
+		break;
+	default:
+		dev_err(pcie->dev, "incompatible iProc PCIe interface\n");
+		return -EINVAL;
+	}
+
+	if (of_find_property(node, "brcm,pcie-msi-inten", NULL))
+		msi->has_inten_reg = true;
+
+	msi->nr_msi_vecs = msi->nr_irqs * EQ_LEN;
+	msi->bitmap = devm_kcalloc(pcie->dev, BITS_TO_LONGS(msi->nr_msi_vecs),
+				   sizeof(*msi->bitmap), GFP_KERNEL);
+	if (!msi->bitmap)
+		return -ENOMEM;
+
+	msi->grps = devm_kcalloc(pcie->dev, msi->nr_irqs, sizeof(*msi->grps),
+				 GFP_KERNEL);
+	if (!msi->grps)
+		return -ENOMEM;
+
+	for (i = 0; i < msi->nr_irqs; i++) {
+		unsigned int irq = irq_of_parse_and_map(node, i);
+
+		if (!irq) {
+			dev_err(pcie->dev, "unable to parse/map interrupt\n");
+			ret = -ENODEV;
+			goto free_irqs;
+		}
+		msi->grps[i].gic_irq = irq;
+		msi->grps[i].msi = msi;
+		msi->grps[i].eq = i;
+	}
+
+	/* Reserve memory for event queue and make sure memories are zeroed */
+	msi->eq_cpu = dma_zalloc_coherent(pcie->dev,
+					  msi->nr_eq_region * EQ_MEM_REGION_SIZE,
+					  &msi->eq_dma, GFP_KERNEL);
+	if (!msi->eq_cpu) {
+		ret = -ENOMEM;
+		goto free_irqs;
+	}
+
+	ret = iproc_msi_alloc_domains(node, msi);
+	if (ret) {
+		dev_err(pcie->dev, "failed to create MSI domains\n");
+		goto free_eq_dma;
+	}
+
+	for_each_online_cpu(cpu) {
+		ret = iproc_msi_irq_setup(msi, cpu);
+		if (ret)
+			goto free_msi_irq;
+	}
+
+	iproc_msi_enable(msi);
+
+	return 0;
+
+free_msi_irq:
+	for_each_online_cpu(cpu)
+		iproc_msi_irq_free(msi, cpu);
+	iproc_msi_free_domains(msi);
+
+free_eq_dma:
+	dma_free_coherent(pcie->dev, msi->nr_eq_region * EQ_MEM_REGION_SIZE,
+			  msi->eq_cpu, msi->eq_dma);
+
+free_irqs:
+	for (i = 0; i < msi->nr_irqs; i++) {
+		if (msi->grps[i].gic_irq)
+			irq_dispose_mapping(msi->grps[i].gic_irq);
+	}
+	pcie->msi = NULL;
+	return ret;
+}
+EXPORT_SYMBOL(iproc_msi_init);
+
+void iproc_msi_exit(struct iproc_pcie *pcie)
+{
+	struct iproc_msi *msi = pcie->msi;
+	unsigned int i, cpu;
+
+	if (!msi)
+		return;
+
+	iproc_msi_disable(msi);
+
+	for_each_online_cpu(cpu)
+		iproc_msi_irq_free(msi, cpu);
+
+	iproc_msi_free_domains(msi);
+
+	dma_free_coherent(pcie->dev, msi->nr_eq_region * EQ_MEM_REGION_SIZE,
+			  msi->eq_cpu, msi->eq_dma);
+
+	for (i = 0; i < msi->nr_irqs; i++) {
+		if (msi->grps[i].gic_irq)
+			irq_dispose_mapping(msi->grps[i].gic_irq);
+	}
+}
+EXPORT_SYMBOL(iproc_msi_exit);