1 files changed, 526 insertions, 0 deletions

diff --git a/drivers/irqchip/irq-gic-v2m.c b/drivers/irqchip/irq-gic-v2m.c
new file mode 100644
index 000000000..f5fe0100f
--- /dev/null
+++ b/drivers/irqchip/irq-gic-v2m.c
@@ -0,0 +1,526 @@
+/*
+ * ARM GIC v2m MSI(-X) support
+ * Support for Message Signaled Interrupts for systems that
+ * implement ARM Generic Interrupt Controller: GICv2m.
+ *
+ * Copyright (C) 2014 Advanced Micro Devices, Inc.
+ * Authors: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
+ *	    Harish Kasiviswanathan <harish.kasiviswanathan@amd.com>
+ *	    Brandon Anderson <brandon.anderson@amd.com>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 as published
+ * by the Free Software Foundation.
+ */
+
+#define pr_fmt(fmt) "GICv2m: " fmt
+
+#include <linux/acpi.h>
+#include <linux/dma-iommu.h>
+#include <linux/irq.h>
+#include <linux/irqdomain.h>
+#include <linux/kernel.h>
+#include <linux/msi.h>
+#include <linux/of_address.h>
+#include <linux/of_pci.h>
+#include <linux/slab.h>
+#include <linux/spinlock.h>
+#include <linux/irqchip/arm-gic.h>
+
+/*
+* MSI_TYPER:
+*     [31:26] Reserved
+*     [25:16] lowest SPI assigned to MSI
+*     [15:10] Reserved
+*     [9:0]   Numer of SPIs assigned to MSI
+*/
+#define V2M_MSI_TYPER		       0x008
+#define V2M_MSI_TYPER_BASE_SHIFT       16
+#define V2M_MSI_TYPER_BASE_MASK	       0x3FF
+#define V2M_MSI_TYPER_NUM_MASK	       0x3FF
+#define V2M_MSI_SETSPI_NS	       0x040
+#define V2M_MIN_SPI		       32
+#define V2M_MAX_SPI		       1019
+#define V2M_MSI_IIDR		       0xFCC
+
+#define V2M_MSI_TYPER_BASE_SPI(x)      \
+	       (((x) >> V2M_MSI_TYPER_BASE_SHIFT) & V2M_MSI_TYPER_BASE_MASK)
+
+#define V2M_MSI_TYPER_NUM_SPI(x)       ((x) & V2M_MSI_TYPER_NUM_MASK)
+
+/* APM X-Gene with GICv2m MSI_IIDR register value */
+#define XGENE_GICV2M_MSI_IIDR		0x06000170
+
+/* Broadcom NS2 GICv2m MSI_IIDR register value */
+#define BCM_NS2_GICV2M_MSI_IIDR		0x0000013f
+
+/* List of flags for specific v2m implementation */
+#define GICV2M_NEEDS_SPI_OFFSET		0x00000001
+
+static LIST_HEAD(v2m_nodes);
+static DEFINE_SPINLOCK(v2m_lock);
+
+struct v2m_data {
+	struct list_head entry;
+	struct fwnode_handle *fwnode;
+	struct resource res;	/* GICv2m resource */
+	void __iomem *base;	/* GICv2m virt address */
+	u32 spi_start;		/* The SPI number that MSIs start */
+	u32 nr_spis;		/* The number of SPIs for MSIs */
+	u32 spi_offset;		/* offset to be subtracted from SPI number */
+	unsigned long *bm;	/* MSI vector bitmap */
+	u32 flags;		/* v2m flags for specific implementation */
+};
+
+static void gicv2m_mask_msi_irq(struct irq_data *d)
+{
+	pci_msi_mask_irq(d);
+	irq_chip_mask_parent(d);
+}
+
+static void gicv2m_unmask_msi_irq(struct irq_data *d)
+{
+	pci_msi_unmask_irq(d);
+	irq_chip_unmask_parent(d);
+}
+
+static struct irq_chip gicv2m_msi_irq_chip = {
+	.name			= "MSI",
+	.irq_mask		= gicv2m_mask_msi_irq,
+	.irq_unmask		= gicv2m_unmask_msi_irq,
+	.irq_eoi		= irq_chip_eoi_parent,
+	.irq_write_msi_msg	= pci_msi_domain_write_msg,
+};
+
+static struct msi_domain_info gicv2m_msi_domain_info = {
+	.flags	= (MSI_FLAG_USE_DEF_DOM_OPS | MSI_FLAG_USE_DEF_CHIP_OPS |
+		   MSI_FLAG_PCI_MSIX | MSI_FLAG_MULTI_PCI_MSI),
+	.chip	= &gicv2m_msi_irq_chip,
+};
+
+static void gicv2m_compose_msi_msg(struct irq_data *data, struct msi_msg *msg)
+{
+	struct v2m_data *v2m = irq_data_get_irq_chip_data(data);
+	phys_addr_t addr = v2m->res.start + V2M_MSI_SETSPI_NS;
+
+	msg->address_hi = upper_32_bits(addr);
+	msg->address_lo = lower_32_bits(addr);
+	msg->data = data->hwirq;
+
+	if (v2m->flags & GICV2M_NEEDS_SPI_OFFSET)
+		msg->data -= v2m->spi_offset;
+
+	iommu_dma_map_msi_msg(data->irq, msg);
+}
+
+static struct irq_chip gicv2m_irq_chip = {
+	.name			= "GICv2m",
+	.irq_mask		= irq_chip_mask_parent,
+	.irq_unmask		= irq_chip_unmask_parent,
+	.irq_eoi		= irq_chip_eoi_parent,
+	.irq_set_affinity	= irq_chip_set_affinity_parent,
+	.irq_compose_msi_msg	= gicv2m_compose_msi_msg,
+};
+
+static int gicv2m_irq_gic_domain_alloc(struct irq_domain *domain,
+				       unsigned int virq,
+				       irq_hw_number_t hwirq)
+{
+	struct irq_fwspec fwspec;
+	struct irq_data *d;
+	int err;
+
+	if (is_of_node(domain->parent->fwnode)) {
+		fwspec.fwnode = domain->parent->fwnode;
+		fwspec.param_count = 3;
+		fwspec.param[0] = 0;
+		fwspec.param[1] = hwirq - 32;
+		fwspec.param[2] = IRQ_TYPE_EDGE_RISING;
+	} else if (is_fwnode_irqchip(domain->parent->fwnode)) {
+		fwspec.fwnode = domain->parent->fwnode;
+		fwspec.param_count = 2;
+		fwspec.param[0] = hwirq;
+		fwspec.param[1] = IRQ_TYPE_EDGE_RISING;
+	} else {
+		return -EINVAL;
+	}
+
+	err = irq_domain_alloc_irqs_parent(domain, virq, 1, &fwspec);
+	if (err)
+		return err;
+
+	/* Configure the interrupt line to be edge */
+	d = irq_domain_get_irq_data(domain->parent, virq);
+	d->chip->irq_set_type(d, IRQ_TYPE_EDGE_RISING);
+	return 0;
+}
+
+static void gicv2m_unalloc_msi(struct v2m_data *v2m, unsigned int hwirq,
+			       int nr_irqs)
+{
+	spin_lock(&v2m_lock);
+	bitmap_release_region(v2m->bm, hwirq - v2m->spi_start,
+			      get_count_order(nr_irqs));
+	spin_unlock(&v2m_lock);
+}
+
+static int gicv2m_irq_domain_alloc(struct irq_domain *domain, unsigned int virq,
+				   unsigned int nr_irqs, void *args)
+{
+	struct v2m_data *v2m = NULL, *tmp;
+	int hwirq, offset, i, err = 0;
+
+	spin_lock(&v2m_lock);
+	list_for_each_entry(tmp, &v2m_nodes, entry) {
+		offset = bitmap_find_free_region(tmp->bm, tmp->nr_spis,
+						 get_count_order(nr_irqs));
+		if (offset >= 0) {
+			v2m = tmp;
+			break;
+		}
+	}
+	spin_unlock(&v2m_lock);
+
+	if (!v2m)
+		return -ENOSPC;
+
+	hwirq = v2m->spi_start + offset;
+
+	for (i = 0; i < nr_irqs; i++) {
+		err = gicv2m_irq_gic_domain_alloc(domain, virq + i, hwirq + i);
+		if (err)
+			goto fail;
+
+		irq_domain_set_hwirq_and_chip(domain, virq + i, hwirq + i,
+					      &gicv2m_irq_chip, v2m);
+	}
+
+	return 0;
+
+fail:
+	irq_domain_free_irqs_parent(domain, virq, nr_irqs);
+	gicv2m_unalloc_msi(v2m, hwirq, nr_irqs);
+	return err;
+}
+
+static void gicv2m_irq_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 v2m_data *v2m = irq_data_get_irq_chip_data(d);
+
+	gicv2m_unalloc_msi(v2m, d->hwirq, nr_irqs);
+	irq_domain_free_irqs_parent(domain, virq, nr_irqs);
+}
+
+static const struct irq_domain_ops gicv2m_domain_ops = {
+	.alloc			= gicv2m_irq_domain_alloc,
+	.free			= gicv2m_irq_domain_free,
+};
+
+static bool is_msi_spi_valid(u32 base, u32 num)
+{
+	if (base < V2M_MIN_SPI) {
+		pr_err("Invalid MSI base SPI (base:%u)\n", base);
+		return false;
+	}
+
+	if ((num == 0) || (base + num > V2M_MAX_SPI)) {
+		pr_err("Number of SPIs (%u) exceed maximum (%u)\n",
+		       num, V2M_MAX_SPI - V2M_MIN_SPI + 1);
+		return false;
+	}
+
+	return true;
+}
+
+static struct irq_chip gicv2m_pmsi_irq_chip = {
+	.name			= "pMSI",
+};
+
+static struct msi_domain_ops gicv2m_pmsi_ops = {
+};
+
+static struct msi_domain_info gicv2m_pmsi_domain_info = {
+	.flags	= (MSI_FLAG_USE_DEF_DOM_OPS | MSI_FLAG_USE_DEF_CHIP_OPS),
+	.ops	= &gicv2m_pmsi_ops,
+	.chip	= &gicv2m_pmsi_irq_chip,
+};
+
+static void gicv2m_teardown(void)
+{
+	struct v2m_data *v2m, *tmp;
+
+	list_for_each_entry_safe(v2m, tmp, &v2m_nodes, entry) {
+		list_del(&v2m->entry);
+		kfree(v2m->bm);
+		iounmap(v2m->base);
+		of_node_put(to_of_node(v2m->fwnode));
+		if (is_fwnode_irqchip(v2m->fwnode))
+			irq_domain_free_fwnode(v2m->fwnode);
+		kfree(v2m);
+	}
+}
+
+static int gicv2m_allocate_domains(struct irq_domain *parent)
+{
+	struct irq_domain *inner_domain, *pci_domain, *plat_domain;
+	struct v2m_data *v2m;
+
+	v2m = list_first_entry_or_null(&v2m_nodes, struct v2m_data, entry);
+	if (!v2m)
+		return 0;
+
+	inner_domain = irq_domain_create_tree(v2m->fwnode,
+					      &gicv2m_domain_ops, v2m);
+	if (!inner_domain) {
+		pr_err("Failed to create GICv2m domain\n");
+		return -ENOMEM;
+	}
+
+	irq_domain_update_bus_token(inner_domain, DOMAIN_BUS_NEXUS);
+	inner_domain->parent = parent;
+	pci_domain = pci_msi_create_irq_domain(v2m->fwnode,
+					       &gicv2m_msi_domain_info,
+					       inner_domain);
+	plat_domain = platform_msi_create_irq_domain(v2m->fwnode,
+						     &gicv2m_pmsi_domain_info,
+						     inner_domain);
+	if (!pci_domain || !plat_domain) {
+		pr_err("Failed to create MSI domains\n");
+		if (plat_domain)
+			irq_domain_remove(plat_domain);
+		if (pci_domain)
+			irq_domain_remove(pci_domain);
+		irq_domain_remove(inner_domain);
+		return -ENOMEM;
+	}
+
+	return 0;
+}
+
+static int __init gicv2m_init_one(struct fwnode_handle *fwnode,
+				  u32 spi_start, u32 nr_spis,
+				  struct resource *res)
+{
+	int ret;
+	struct v2m_data *v2m;
+
+	v2m = kzalloc(sizeof(struct v2m_data), GFP_KERNEL);
+	if (!v2m) {
+		pr_err("Failed to allocate struct v2m_data.\n");
+		return -ENOMEM;
+	}
+
+	INIT_LIST_HEAD(&v2m->entry);
+	v2m->fwnode = fwnode;
+
+	memcpy(&v2m->res, res, sizeof(struct resource));
+
+	v2m->base = ioremap(v2m->res.start, resource_size(&v2m->res));
+	if (!v2m->base) {
+		pr_err("Failed to map GICv2m resource\n");
+		ret = -ENOMEM;
+		goto err_free_v2m;
+	}
+
+	if (spi_start && nr_spis) {
+		v2m->spi_start = spi_start;
+		v2m->nr_spis = nr_spis;
+	} else {
+		u32 typer = readl_relaxed(v2m->base + V2M_MSI_TYPER);
+
+		v2m->spi_start = V2M_MSI_TYPER_BASE_SPI(typer);
+		v2m->nr_spis = V2M_MSI_TYPER_NUM_SPI(typer);
+	}
+
+	if (!is_msi_spi_valid(v2m->spi_start, v2m->nr_spis)) {
+		ret = -EINVAL;
+		goto err_iounmap;
+	}
+
+	/*
+	 * APM X-Gene GICv2m implementation has an erratum where
+	 * the MSI data needs to be the offset from the spi_start
+	 * in order to trigger the correct MSI interrupt. This is
+	 * different from the standard GICv2m implementation where
+	 * the MSI data is the absolute value within the range from
+	 * spi_start to (spi_start + num_spis).
+	 *
+	 * Broadom NS2 GICv2m implementation has an erratum where the MSI data
+	 * is 'spi_number - 32'
+	 */
+	switch (readl_relaxed(v2m->base + V2M_MSI_IIDR)) {
+	case XGENE_GICV2M_MSI_IIDR:
+		v2m->flags |= GICV2M_NEEDS_SPI_OFFSET;
+		v2m->spi_offset = v2m->spi_start;
+		break;
+	case BCM_NS2_GICV2M_MSI_IIDR:
+		v2m->flags |= GICV2M_NEEDS_SPI_OFFSET;
+		v2m->spi_offset = 32;
+		break;
+	}
+
+	v2m->bm = kcalloc(BITS_TO_LONGS(v2m->nr_spis), sizeof(long),
+			  GFP_KERNEL);
+	if (!v2m->bm) {
+		ret = -ENOMEM;
+		goto err_iounmap;
+	}
+
+	list_add_tail(&v2m->entry, &v2m_nodes);
+
+	pr_info("range%pR, SPI[%d:%d]\n", res,
+		v2m->spi_start, (v2m->spi_start + v2m->nr_spis - 1));
+	return 0;
+
+err_iounmap:
+	iounmap(v2m->base);
+err_free_v2m:
+	kfree(v2m);
+	return ret;
+}
+
+static struct of_device_id gicv2m_device_id[] = {
+	{	.compatible	= "arm,gic-v2m-frame",	},
+	{},
+};
+
+static int __init gicv2m_of_init(struct fwnode_handle *parent_handle,
+				 struct irq_domain *parent)
+{
+	int ret = 0;
+	struct device_node *node = to_of_node(parent_handle);
+	struct device_node *child;
+
+	for (child = of_find_matching_node(node, gicv2m_device_id); child;
+	     child = of_find_matching_node(child, gicv2m_device_id)) {
+		u32 spi_start = 0, nr_spis = 0;
+		struct resource res;
+
+		if (!of_find_property(child, "msi-controller", NULL))
+			continue;
+
+		ret = of_address_to_resource(child, 0, &res);
+		if (ret) {
+			pr_err("Failed to allocate v2m resource.\n");
+			break;
+		}
+
+		if (!of_property_read_u32(child, "arm,msi-base-spi",
+					  &spi_start) &&
+		    !of_property_read_u32(child, "arm,msi-num-spis", &nr_spis))
+			pr_info("DT overriding V2M MSI_TYPER (base:%u, num:%u)\n",
+				spi_start, nr_spis);
+
+		ret = gicv2m_init_one(&child->fwnode, spi_start, nr_spis, &res);
+		if (ret) {
+			of_node_put(child);
+			break;
+		}
+	}
+
+	if (!ret)
+		ret = gicv2m_allocate_domains(parent);
+	if (ret)
+		gicv2m_teardown();
+	return ret;
+}
+
+#ifdef CONFIG_ACPI
+static int acpi_num_msi;
+
+static struct fwnode_handle *gicv2m_get_fwnode(struct device *dev)
+{
+	struct v2m_data *data;
+
+	if (WARN_ON(acpi_num_msi <= 0))
+		return NULL;
+
+	/* We only return the fwnode of the first MSI frame. */
+	data = list_first_entry_or_null(&v2m_nodes, struct v2m_data, entry);
+	if (!data)
+		return NULL;
+
+	return data->fwnode;
+}
+
+static int __init
+acpi_parse_madt_msi(struct acpi_subtable_header *header,
+		    const unsigned long end)
+{
+	int ret;
+	struct resource res;
+	u32 spi_start = 0, nr_spis = 0;
+	struct acpi_madt_generic_msi_frame *m;
+	struct fwnode_handle *fwnode;
+
+	m = (struct acpi_madt_generic_msi_frame *)header;
+	if (BAD_MADT_ENTRY(m, end))
+		return -EINVAL;
+
+	res.start = m->base_address;
+	res.end = m->base_address + SZ_4K - 1;
+	res.flags = IORESOURCE_MEM;
+
+	if (m->flags & ACPI_MADT_OVERRIDE_SPI_VALUES) {
+		spi_start = m->spi_base;
+		nr_spis = m->spi_count;
+
+		pr_info("ACPI overriding V2M MSI_TYPER (base:%u, num:%u)\n",
+			spi_start, nr_spis);
+	}
+
+	fwnode = irq_domain_alloc_fwnode((void *)m->base_address);
+	if (!fwnode) {
+		pr_err("Unable to allocate GICv2m domain token\n");
+		return -EINVAL;
+	}
+
+	ret = gicv2m_init_one(fwnode, spi_start, nr_spis, &res);
+	if (ret)
+		irq_domain_free_fwnode(fwnode);
+
+	return ret;
+}
+
+static int __init gicv2m_acpi_init(struct irq_domain *parent)
+{
+	int ret;
+
+	if (acpi_num_msi > 0)
+		return 0;
+
+	acpi_num_msi = acpi_table_parse_madt(ACPI_MADT_TYPE_GENERIC_MSI_FRAME,
+				      acpi_parse_madt_msi, 0);
+
+	if (acpi_num_msi <= 0)
+		goto err_out;
+
+	ret = gicv2m_allocate_domains(parent);
+	if (ret)
+		goto err_out;
+
+	pci_msi_register_fwnode_provider(&gicv2m_get_fwnode);
+
+	return 0;
+
+err_out:
+	gicv2m_teardown();
+	return -EINVAL;
+}
+#else /* CONFIG_ACPI */
+static int __init gicv2m_acpi_init(struct irq_domain *parent)
+{
+	return -EINVAL;
+}
+#endif /* CONFIG_ACPI */
+
+int __init gicv2m_init(struct fwnode_handle *parent_handle,
+		       struct irq_domain *parent)
+{
+	if (is_of_node(parent_handle))
+		return gicv2m_of_init(parent_handle, parent);
+
+	return gicv2m_acpi_init(parent);
+}