From: Megha Dey <[email protected]> Add support for the creation of a new DEV_MSI irq domain. It creates a new irq chip associated with the DEV_MSI domain and adds the necessary domain operations to it.
Add a new config option DEV_MSI which must be enabled by any driver that wants to support device-specific message-signaled-interrupts outside of PCI-MSI(-X). Lastly, add device specific mask/unmask callbacks in addition to a write function to the platform_msi_ops. Reviewed-by: Dan Williams <[email protected]> Signed-off-by: Megha Dey <[email protected]> Signed-off-by: Dave Jiang <[email protected]> --- arch/x86/include/asm/hw_irq.h | 5 ++ drivers/base/Kconfig | 7 +++ drivers/base/Makefile | 1 drivers/base/dev-msi.c | 95 +++++++++++++++++++++++++++++++++++++++++ drivers/base/platform-msi.c | 45 +++++++++++++------ drivers/base/platform-msi.h | 23 ++++++++++ include/linux/msi.h | 8 +++ 7 files changed, 168 insertions(+), 16 deletions(-) create mode 100644 drivers/base/dev-msi.c create mode 100644 drivers/base/platform-msi.h diff --git a/arch/x86/include/asm/hw_irq.h b/arch/x86/include/asm/hw_irq.h index 74c12437401e..8ecd7570589d 100644 --- a/arch/x86/include/asm/hw_irq.h +++ b/arch/x86/include/asm/hw_irq.h @@ -61,6 +61,11 @@ struct irq_alloc_info { irq_hw_number_t msi_hwirq; }; #endif +#ifdef CONFIG_DEV_MSI + struct { + irq_hw_number_t hwirq; + }; +#endif #ifdef CONFIG_X86_IO_APIC struct { int ioapic_id; diff --git a/drivers/base/Kconfig b/drivers/base/Kconfig index 8d7001712062..f00901bac056 100644 --- a/drivers/base/Kconfig +++ b/drivers/base/Kconfig @@ -210,4 +210,11 @@ config GENERIC_ARCH_TOPOLOGY appropriate scaling, sysfs interface for reading capacity values at runtime. +config DEV_MSI + bool "Device Specific Interrupt Messages" + select IRQ_DOMAIN_HIERARCHY + select GENERIC_MSI_IRQ_DOMAIN + help + Allow device drivers to generate device-specific interrupt messages + for devices independent of PCI MSI/-X. endmenu diff --git a/drivers/base/Makefile b/drivers/base/Makefile index 157452080f3d..ca1e4d39164e 100644 --- a/drivers/base/Makefile +++ b/drivers/base/Makefile @@ -21,6 +21,7 @@ obj-$(CONFIG_REGMAP) += regmap/ obj-$(CONFIG_SOC_BUS) += soc.o obj-$(CONFIG_PINCTRL) += pinctrl.o obj-$(CONFIG_DEV_COREDUMP) += devcoredump.o +obj-$(CONFIG_DEV_MSI) += dev-msi.o obj-$(CONFIG_GENERIC_MSI_IRQ_DOMAIN) += platform-msi.o obj-$(CONFIG_GENERIC_ARCH_TOPOLOGY) += arch_topology.o diff --git a/drivers/base/dev-msi.c b/drivers/base/dev-msi.c new file mode 100644 index 000000000000..240ccc353933 --- /dev/null +++ b/drivers/base/dev-msi.c @@ -0,0 +1,95 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright © 2020 Intel Corporation. + * + * Author: Megha Dey <[email protected]> + */ + +#include <linux/irq.h> +#include <linux/irqdomain.h> +#include <linux/msi.h> +#include "platform-msi.h" + +struct irq_domain *dev_msi_default_domain; + +static irq_hw_number_t dev_msi_get_hwirq(struct msi_domain_info *info, + msi_alloc_info_t *arg) +{ + return arg->hwirq; +} + +static irq_hw_number_t dev_msi_calc_hwirq(struct msi_desc *desc) +{ + u32 devid; + + devid = desc->platform.msi_priv_data->devid; + + return (devid << (32 - DEV_ID_SHIFT)) | desc->platform.msi_index; +} + +static void dev_msi_set_desc(msi_alloc_info_t *arg, struct msi_desc *desc) +{ + arg->hwirq = dev_msi_calc_hwirq(desc); +} + +static int dev_msi_prepare(struct irq_domain *domain, struct device *dev, + int nvec, msi_alloc_info_t *arg) +{ + memset(arg, 0, sizeof(*arg)); + + return 0; +} + +static struct msi_domain_ops dev_msi_domain_ops = { + .get_hwirq = dev_msi_get_hwirq, + .set_desc = dev_msi_set_desc, + .msi_prepare = dev_msi_prepare, +}; + +static struct irq_chip dev_msi_controller = { + .name = "DEV-MSI", + .irq_unmask = platform_msi_unmask_irq, + .irq_mask = platform_msi_mask_irq, + .irq_write_msi_msg = platform_msi_write_msg, + .irq_ack = irq_chip_ack_parent, + .irq_retrigger = irq_chip_retrigger_hierarchy, + .flags = IRQCHIP_SKIP_SET_WAKE, +}; + +static struct msi_domain_info dev_msi_domain_info = { + .flags = MSI_FLAG_USE_DEF_DOM_OPS | MSI_FLAG_USE_DEF_CHIP_OPS, + .ops = &dev_msi_domain_ops, + .chip = &dev_msi_controller, + .handler = handle_edge_irq, + .handler_name = "edge", +}; + +static int __init create_dev_msi_domain(void) +{ + struct irq_domain *parent = NULL; + struct fwnode_handle *fn; + + /* + * Modern code should never have to use irq_get_default_host. But since + * dev-msi is invisible to DT/ACPI, this is an exception case. + */ + parent = irq_get_default_host(); + if (!parent) + return -ENXIO; + + fn = irq_domain_alloc_named_fwnode("DEV_MSI"); + if (!fn) + return -ENXIO; + + dev_msi_default_domain = msi_create_irq_domain(fn, &dev_msi_domain_info, parent); + if (!dev_msi_default_domain) { + pr_warn("failed to initialize irqdomain for DEV-MSI.\n"); + return -ENXIO; + } + + irq_domain_update_bus_token(dev_msi_default_domain, DOMAIN_BUS_PLATFORM_MSI); + irq_domain_free_fwnode(fn); + + return 0; +} +device_initcall(create_dev_msi_domain); diff --git a/drivers/base/platform-msi.c b/drivers/base/platform-msi.c index 9d94cd699468..5e1f210d65ee 100644 --- a/drivers/base/platform-msi.c +++ b/drivers/base/platform-msi.c @@ -12,21 +12,7 @@ #include <linux/irqdomain.h> #include <linux/msi.h> #include <linux/slab.h> - -#define DEV_ID_SHIFT 21 -#define MAX_DEV_MSIS (1 << (32 - DEV_ID_SHIFT)) - -/* - * Internal data structure containing a (made up, but unique) devid - * and the platform-msi ops - */ -struct platform_msi_priv_data { - struct device *dev; - void *host_data; - msi_alloc_info_t arg; - const struct platform_msi_ops *ops; - int devid; -}; +#include "platform-msi.h" /* The devid allocator */ static DEFINE_IDA(platform_msi_devid_ida); @@ -76,7 +62,7 @@ static void platform_msi_update_dom_ops(struct msi_domain_info *info) ops->set_desc = platform_msi_set_desc; } -static void platform_msi_write_msg(struct irq_data *data, struct msi_msg *msg) +void platform_msi_write_msg(struct irq_data *data, struct msi_msg *msg) { struct msi_desc *desc = irq_data_get_msi_desc(data); struct platform_msi_priv_data *priv_data; @@ -86,6 +72,33 @@ static void platform_msi_write_msg(struct irq_data *data, struct msi_msg *msg) priv_data->ops->write_msg(desc, msg); } +static void __platform_msi_desc_mask_unmask_irq(struct msi_desc *desc, u32 mask) +{ + const struct platform_msi_ops *ops; + + ops = desc->platform.msi_priv_data->ops; + if (!ops) + return; + + if (mask) { + if (ops->irq_mask) + ops->irq_mask(desc); + } else { + if (ops->irq_unmask) + ops->irq_unmask(desc); + } +} + +void platform_msi_mask_irq(struct irq_data *data) +{ + __platform_msi_desc_mask_unmask_irq(irq_data_get_msi_desc(data), 1); +} + +void platform_msi_unmask_irq(struct irq_data *data) +{ + __platform_msi_desc_mask_unmask_irq(irq_data_get_msi_desc(data), 0); +} + static void platform_msi_update_chip_ops(struct msi_domain_info *info) { struct irq_chip *chip = info->chip; diff --git a/drivers/base/platform-msi.h b/drivers/base/platform-msi.h new file mode 100644 index 000000000000..1de8c2874218 --- /dev/null +++ b/drivers/base/platform-msi.h @@ -0,0 +1,23 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * Copyright © 2020 Intel Corporation. + * + * Author: Megha Dey <[email protected]> + */ + +#include <linux/msi.h> + +#define DEV_ID_SHIFT 21 +#define MAX_DEV_MSIS (1 << (32 - DEV_ID_SHIFT)) + +/* + * Data structure containing a (made up, but unique) devid + * and the platform-msi ops. + */ +struct platform_msi_priv_data { + struct device *dev; + void *host_data; + msi_alloc_info_t arg; + const struct platform_msi_ops *ops; + int devid; +}; diff --git a/include/linux/msi.h b/include/linux/msi.h index 7f6a8eb51aca..1da97f905720 100644 --- a/include/linux/msi.h +++ b/include/linux/msi.h @@ -323,9 +323,13 @@ enum { /* * platform_msi_ops - Callbacks for platform MSI ops + * @irq_mask: mask an interrupt source + * @irq_unmask: unmask an interrupt source * @write_msg: write message content */ struct platform_msi_ops { + unsigned int (*irq_mask)(struct msi_desc *desc); + unsigned int (*irq_unmask)(struct msi_desc *desc); irq_write_msi_msg_t write_msg; }; @@ -370,6 +374,10 @@ int platform_msi_domain_alloc(struct irq_domain *domain, unsigned int virq, void platform_msi_domain_free(struct irq_domain *domain, unsigned int virq, unsigned int nvec); void *platform_msi_get_host_data(struct irq_domain *domain); + +void platform_msi_write_msg(struct irq_data *data, struct msi_msg *msg); +void platform_msi_unmask_irq(struct irq_data *data); +void platform_msi_mask_irq(struct irq_data *data); #endif /* CONFIG_GENERIC_MSI_IRQ_DOMAIN */ #ifdef CONFIG_PCI_MSI_IRQ_DOMAIN
