1 files changed, 331 insertions, 0 deletions
diff --git a/drivers/irqchip/irq-gic-v3-mbi.c b/drivers/irqchip/irq-gic-v3-mbi.c
new file mode 100644
index 000000000000..ad70e7c416e3
--- /dev/null
+++ b/drivers/irqchip/irq-gic-v3-mbi.c
@@ -0,0 +1,331 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2018 ARM Limited, All Rights Reserved.
+ * Author: Marc Zyngier <marc.zyngier@arm.com>
+ */
+
+#define pr_fmt(fmt) "GICv3: " fmt
+
+#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-v3.h>
+
+struct mbi_range {
+	u32			spi_start;
+	u32			nr_spis;
+	unsigned long		*bm;
+};
+
+static struct mutex		mbi_lock;
+static phys_addr_t		mbi_phys_base;
+static struct mbi_range		*mbi_ranges;
+static unsigned int		mbi_range_nr;
+
+static struct irq_chip mbi_irq_chip = {
+	.name			= "MBI",
+	.irq_mask		= irq_chip_mask_parent,
+	.irq_unmask		= irq_chip_unmask_parent,
+	.irq_eoi		= irq_chip_eoi_parent,
+	.irq_set_type		= irq_chip_set_type_parent,
+	.irq_set_affinity	= irq_chip_set_affinity_parent,
+};
+
+static int mbi_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;
+
+	/*
+	 * Using ACPI? There is no MBI support in the spec, you
+	 * shouldn't even be here.
+	 */
+	if (!is_of_node(domain->parent->fwnode))
+		return -EINVAL;
+
+	/*
+	 * Let's default to edge. This is consistent with traditional
+	 * MSIs, and systems requiring level signaling will just
+	 * enforce the trigger on their own.
+	 */
+	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;
+
+	err = irq_domain_alloc_irqs_parent(domain, virq, 1, &fwspec);
+	if (err)
+		return err;
+
+	d = irq_domain_get_irq_data(domain->parent, virq);
+	return d->chip->irq_set_type(d, IRQ_TYPE_EDGE_RISING);
+}
+
+static void mbi_free_msi(struct mbi_range *mbi, unsigned int hwirq,
+			 int nr_irqs)
+{
+	mutex_lock(&mbi_lock);
+	bitmap_release_region(mbi->bm, hwirq - mbi->spi_start,
+			      get_count_order(nr_irqs));
+	mutex_unlock(&mbi_lock);
+}
+
+static int mbi_irq_domain_alloc(struct irq_domain *domain, unsigned int virq,
+				   unsigned int nr_irqs, void *args)
+{
+	struct mbi_range *mbi = NULL;
+	int hwirq, offset, i, err = 0;
+
+	mutex_lock(&mbi_lock);
+	for (i = 0; i < mbi_range_nr; i++) {
+		offset = bitmap_find_free_region(mbi_ranges[i].bm,
+						 mbi_ranges[i].nr_spis,
+						 get_count_order(nr_irqs));
+		if (offset >= 0) {
+			mbi = &mbi_ranges[i];
+			break;
+		}
+	}
+	mutex_unlock(&mbi_lock);
+
+	if (!mbi)
+		return -ENOSPC;
+
+	hwirq = mbi->spi_start + offset;
+
+	for (i = 0; i < nr_irqs; i++) {
+		err = mbi_irq_gic_domain_alloc(domain, virq + i, hwirq + i);
+		if (err)
+			goto fail;
+
+		irq_domain_set_hwirq_and_chip(domain, virq + i, hwirq + i,
+					      &mbi_irq_chip, mbi);
+	}
+
+	return 0;
+
+fail:
+	irq_domain_free_irqs_parent(domain, virq, nr_irqs);
+	mbi_free_msi(mbi, hwirq, nr_irqs);
+	return err;
+}
+
+static void mbi_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 mbi_range *mbi = irq_data_get_irq_chip_data(d);
+
+	mbi_free_msi(mbi, d->hwirq, nr_irqs);
+	irq_domain_free_irqs_parent(domain, virq, nr_irqs);
+}
+
+static const struct irq_domain_ops mbi_domain_ops = {
+	.alloc			= mbi_irq_domain_alloc,
+	.free			= mbi_irq_domain_free,
+};
+
+static void mbi_compose_msi_msg(struct irq_data *data, struct msi_msg *msg)
+{
+	msg[0].address_hi = upper_32_bits(mbi_phys_base + GICD_SETSPI_NSR);
+	msg[0].address_lo = lower_32_bits(mbi_phys_base + GICD_SETSPI_NSR);
+	msg[0].data = data->parent_data->hwirq;
+
+	iommu_dma_map_msi_msg(data->irq, msg);
+}
+
+#ifdef CONFIG_PCI_MSI
+/* PCI-specific irqchip */
+static void mbi_mask_msi_irq(struct irq_data *d)
+{
+	pci_msi_mask_irq(d);
+	irq_chip_mask_parent(d);
+}
+
+static void mbi_unmask_msi_irq(struct irq_data *d)
+{
+	pci_msi_unmask_irq(d);
+	irq_chip_unmask_parent(d);
+}
+
+static struct irq_chip mbi_msi_irq_chip = {
+	.name			= "MSI",
+	.irq_mask		= mbi_mask_msi_irq,
+	.irq_unmask		= mbi_unmask_msi_irq,
+	.irq_eoi		= irq_chip_eoi_parent,
+	.irq_compose_msi_msg	= mbi_compose_msi_msg,
+	.irq_write_msi_msg	= pci_msi_domain_write_msg,
+};
+
+static struct msi_domain_info mbi_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	= &mbi_msi_irq_chip,
+};
+
+static int mbi_allocate_pci_domain(struct irq_domain *nexus_domain,
+				   struct irq_domain **pci_domain)
+{
+	*pci_domain = pci_msi_create_irq_domain(nexus_domain->parent->fwnode,
+						&mbi_msi_domain_info,
+						nexus_domain);
+	if (!*pci_domain)
+		return -ENOMEM;
+
+	return 0;
+}
+#else
+static int mbi_allocate_pci_domain(struct irq_domain *nexus_domain,
+				   struct irq_domain **pci_domain)
+{
+	*pci_domain = NULL;
+	return 0;
+}
+#endif
+
+static void mbi_compose_mbi_msg(struct irq_data *data, struct msi_msg *msg)
+{
+	mbi_compose_msi_msg(data, msg);
+
+	msg[1].address_hi = upper_32_bits(mbi_phys_base + GICD_CLRSPI_NSR);
+	msg[1].address_lo = lower_32_bits(mbi_phys_base + GICD_CLRSPI_NSR);
+	msg[1].data = data->parent_data->hwirq;
+
+	iommu_dma_map_msi_msg(data->irq, &msg[1]);
+}
+
+/* Platform-MSI specific irqchip */
+static struct irq_chip mbi_pmsi_irq_chip = {
+	.name			= "pMSI",
+	.irq_set_type		= irq_chip_set_type_parent,
+	.irq_compose_msi_msg	= mbi_compose_mbi_msg,
+	.flags			= IRQCHIP_SUPPORTS_LEVEL_MSI,
+};
+
+static struct msi_domain_ops mbi_pmsi_ops = {
+};
+
+static struct msi_domain_info mbi_pmsi_domain_info = {
+	.flags	= (MSI_FLAG_USE_DEF_DOM_OPS | MSI_FLAG_USE_DEF_CHIP_OPS |
+		   MSI_FLAG_LEVEL_CAPABLE),
+	.ops	= &mbi_pmsi_ops,
+	.chip	= &mbi_pmsi_irq_chip,
+};
+
+static int mbi_allocate_domains(struct irq_domain *parent)
+{
+	struct irq_domain *nexus_domain, *pci_domain, *plat_domain;
+	int err;
+
+	nexus_domain = irq_domain_create_tree(parent->fwnode,
+					      &mbi_domain_ops, NULL);
+	if (!nexus_domain)
+		return -ENOMEM;
+
+	irq_domain_update_bus_token(nexus_domain, DOMAIN_BUS_NEXUS);
+	nexus_domain->parent = parent;
+
+	err = mbi_allocate_pci_domain(nexus_domain, &pci_domain);
+
+	plat_domain = platform_msi_create_irq_domain(parent->fwnode,
+						     &mbi_pmsi_domain_info,
+						     nexus_domain);
+
+	if (err || !plat_domain) {
+		if (plat_domain)
+			irq_domain_remove(plat_domain);
+		if (pci_domain)
+			irq_domain_remove(pci_domain);
+		irq_domain_remove(nexus_domain);
+		return -ENOMEM;
+	}
+
+	return 0;
+}
+
+int __init mbi_init(struct fwnode_handle *fwnode, struct irq_domain *parent)
+{
+	struct device_node *np;
+	const __be32 *reg;
+	int ret, n;
+
+	np = to_of_node(fwnode);
+
+	if (!of_property_read_bool(np, "msi-controller"))
+		return 0;
+
+	n = of_property_count_elems_of_size(np, "mbi-ranges", sizeof(u32));
+	if (n <= 0 || n % 2)
+		return -EINVAL;
+
+	mbi_range_nr = n / 2;
+	mbi_ranges = kcalloc(mbi_range_nr, sizeof(*mbi_ranges), GFP_KERNEL);
+	if (!mbi_ranges)
+		return -ENOMEM;
+
+	for (n = 0; n < mbi_range_nr; n++) {
+		ret = of_property_read_u32_index(np, "mbi-ranges", n * 2,
+						 &mbi_ranges[n].spi_start);
+		if (ret)
+			goto err_free_mbi;
+		ret = of_property_read_u32_index(np, "mbi-ranges", n * 2 + 1,
+						 &mbi_ranges[n].nr_spis);
+		if (ret)
+			goto err_free_mbi;
+
+		mbi_ranges[n].bm = kcalloc(BITS_TO_LONGS(mbi_ranges[n].nr_spis),
+					   sizeof(long), GFP_KERNEL);
+		if (!mbi_ranges[n].bm) {
+			ret = -ENOMEM;
+			goto err_free_mbi;
+		}
+		pr_info("MBI range [%d:%d]\n", mbi_ranges[n].spi_start,
+			mbi_ranges[n].spi_start + mbi_ranges[n].nr_spis - 1);
+	}
+
+	reg = of_get_property(np, "mbi-alias", NULL);
+	if (reg) {
+		mbi_phys_base = of_translate_address(np, reg);
+		if (mbi_phys_base == OF_BAD_ADDR) {
+			ret = -ENXIO;
+			goto err_free_mbi;
+		}
+	} else {
+		struct resource res;
+
+		if (of_address_to_resource(np, 0, &res)) {
+			ret = -ENXIO;
+			goto err_free_mbi;
+		}
+
+		mbi_phys_base = res.start;
+	}
+
+	pr_info("Using MBI frame %pa\n", &mbi_phys_base);
+
+	ret = mbi_allocate_domains(parent);
+	if (ret)
+		goto err_free_mbi;
+
+	return 0;
+
+err_free_mbi:
+	if (mbi_ranges) {
+		for (n = 0; n < mbi_range_nr; n++)
+			kfree(mbi_ranges[n].bm);
+		kfree(mbi_ranges);
+	}
+
+	return ret;
+}