From 505287525c24d5c78b662fd73721ad9900b91fcc Mon Sep 17 00:00:00 2001 From: Marc Zyngier Date: Tue, 8 May 2018 13:14:36 +0100 Subject: [PATCH] irqchip/gic-v3: Add support for Message Based Interrupts as an MSI controller GICv3 offers the possibility to signal SPIs using a pair of doorbells (SETPI, CLRSPI) under the name of Message Based Interrupts (MBI). They can be used as either traditional (edge) MSIs, or the more exotic level-triggered flavour. Let's implement support for platform MSI, which is the original intent for this feature. Signed-off-by: Marc Zyngier Signed-off-by: Thomas Gleixner Cc: Rob Herring Cc: Jason Cooper Cc: Ard Biesheuvel Cc: Srinivas Kandagatla Cc: Thomas Petazzoni Cc: Miquel Raynal Link: https://lkml.kernel.org/r/20180508121438.11301-8-marc.zyngier@arm.com --- drivers/irqchip/Makefile | 2 +- drivers/irqchip/irq-gic-v3-mbi.c | 275 +++++++++++++++++++++++++++++ drivers/irqchip/irq-gic-v3.c | 6 + include/linux/irqchip/arm-gic-v3.h | 1 + 4 files changed, 283 insertions(+), 1 deletion(-) create mode 100644 drivers/irqchip/irq-gic-v3-mbi.c diff --git a/drivers/irqchip/Makefile b/drivers/irqchip/Makefile index 5ed465ab1c76..15f268f646bf 100644 --- a/drivers/irqchip/Makefile +++ b/drivers/irqchip/Makefile @@ -27,7 +27,7 @@ obj-$(CONFIG_ARM_GIC) += irq-gic.o irq-gic-common.o obj-$(CONFIG_ARM_GIC_PM) += irq-gic-pm.o obj-$(CONFIG_ARCH_REALVIEW) += irq-gic-realview.o obj-$(CONFIG_ARM_GIC_V2M) += irq-gic-v2m.o -obj-$(CONFIG_ARM_GIC_V3) += irq-gic-v3.o irq-gic-common.o +obj-$(CONFIG_ARM_GIC_V3) += irq-gic-v3.o irq-gic-v3-mbi.o irq-gic-common.o obj-$(CONFIG_ARM_GIC_V3_ITS) += irq-gic-v3-its.o irq-gic-v3-its-platform-msi.o irq-gic-v4.o obj-$(CONFIG_ARM_GIC_V3_ITS_PCI) += irq-gic-v3-its-pci-msi.o obj-$(CONFIG_ARM_GIC_V3_ITS_FSL_MC) += irq-gic-v3-its-fsl-mc-msi.o diff --git a/drivers/irqchip/irq-gic-v3-mbi.c b/drivers/irqchip/irq-gic-v3-mbi.c new file mode 100644 index 000000000000..2b3b767050aa --- /dev/null +++ b/drivers/irqchip/irq-gic-v3-mbi.c @@ -0,0 +1,275 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (C) 2018 ARM Limited, All Rights Reserved. + * Author: Marc Zyngier + */ + +#define pr_fmt(fmt) "GICv3: " fmt + +#include +#include +#include +#include +#include +#include +#include +#include + +#include + +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); +} + +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, *plat_domain; + + 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; + + plat_domain = platform_msi_create_irq_domain(parent->fwnode, + &mbi_pmsi_domain_info, + nexus_domain); + + if (!plat_domain) { + irq_domain_remove(plat_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; +} diff --git a/drivers/irqchip/irq-gic-v3.c b/drivers/irqchip/irq-gic-v3.c index 94164d7b87a6..5a67ec084588 100644 --- a/drivers/irqchip/irq-gic-v3.c +++ b/drivers/irqchip/irq-gic-v3.c @@ -1113,6 +1113,12 @@ static int __init gic_init_bases(void __iomem *dist_base, pr_info("Distributor has %sRange Selector support\n", gic_data.has_rss ? "" : "no "); + if (typer & GICD_TYPER_MBIS) { + err = mbi_init(handle, gic_data.domain); + if (err) + pr_err("Failed to initialize MBIs\n"); + } + set_handle_irq(gic_handle_irq); gic_update_vlpi_properties(); diff --git a/include/linux/irqchip/arm-gic-v3.h b/include/linux/irqchip/arm-gic-v3.h index f5af3b594e6e..cbb872c1b607 100644 --- a/include/linux/irqchip/arm-gic-v3.h +++ b/include/linux/irqchip/arm-gic-v3.h @@ -587,6 +587,7 @@ struct fwnode_handle; int its_cpu_init(void); int its_init(struct fwnode_handle *handle, struct rdists *rdists, struct irq_domain *domain); +int mbi_init(struct fwnode_handle *fwnode, struct irq_domain *parent); static inline bool gic_enable_sre(void) {