diff options
Diffstat (limited to 'arch/x86/include/asm/pirq_routing.h')
| -rw-r--r-- | arch/x86/include/asm/pirq_routing.h | 142 |
1 files changed, 142 insertions, 0 deletions
diff --git a/arch/x86/include/asm/pirq_routing.h b/arch/x86/include/asm/pirq_routing.h new file mode 100644 index 0000000..67e5c44 --- /dev/null +++ b/arch/x86/include/asm/pirq_routing.h @@ -0,0 +1,142 @@ +/* SPDX-License-Identifier: GPL-2.0+ */ +/* + * Copyright (C) 2015, Bin Meng <bmeng.cn@gmail.com> + * + * Ported from coreboot src/arch/x86/include/arch/pirq_routing.h + */ + +#ifndef _PIRQ_ROUTING_H_ +#define _PIRQ_ROUTING_H_ + +/* + * This is the maximum number on interrupt entries that a PCI device may have. + * This is NOT the number of slots or devices in the system + * This is NOT the number of entries in the PIRQ table + * + * This tells us that in the PIRQ table, we are going to have 4 link-bitmap + * entries per PCI device which is fixed at 4: INTA, INTB, INTC, and INTD. + * + * CAUTION: If you change this, PIRQ routing will not work correctly. + */ +#define MAX_INTX_ENTRIES 4 + +#define PIRQ_SIGNATURE \ + (('$' << 0) + ('P' << 8) + ('I' << 16) + ('R' << 24)) +#define PIRQ_VERSION 0x0100 + +struct __packed irq_info { + u8 bus; /* Bus number */ + u8 devfn; /* Device and function number */ + struct __packed { + u8 link; /* IRQ line ID, 0=not routed */ + u16 bitmap; /* Available IRQs */ + } irq[MAX_INTX_ENTRIES]; + u8 slot; /* Slot number, 0=onboard */ + u8 rfu; +}; + +struct __packed irq_routing_table { + u32 signature; /* PIRQ_SIGNATURE */ + u16 version; /* PIRQ_VERSION */ + u16 size; /* Table size in bytes */ + u8 rtr_bus; /* busno of the interrupt router */ + u8 rtr_devfn; /* devfn of the interrupt router */ + u16 exclusive_irqs; /* IRQs devoted exclusively to PCI usage */ + u16 rtr_vendor; /* Vendor ID of the interrupt router */ + u16 rtr_device; /* Device ID of the interrupt router */ + u32 miniport_data; + u8 rfu[11]; + u8 checksum; /* Modulo 256 checksum must give zero */ + struct irq_info slots[CONFIG_IRQ_SLOT_COUNT]; +}; + +/** + * get_irq_slot_count() - Get the number of entries in the irq_info table + * + * This calculates the number of entries for the irq_info table. + * + * @rt: pointer to the base address of the struct irq_info + * @return: number of entries + */ +static inline int get_irq_slot_count(struct irq_routing_table *rt) +{ + return (rt->size - 32) / sizeof(struct irq_info); +} + +/** + * pirq_check_irq_routed() - Check whether an IRQ is routed to 8259 PIC + * + * This function checks whether an IRQ is routed to 8259 PIC for a given link. + * + * Note: this function should be provided by the platform codes, as the + * implementation of interrupt router may be different. + * + * @dev: irq router's udevice + * @link: link number which represents a PIRQ + * @irq: the 8259 IRQ number + * @return: true if the irq is already routed to 8259 for a given link, + * false elsewise + */ +bool pirq_check_irq_routed(struct udevice *dev, int link, u8 irq); + +/** + * pirq_translate_link() - Translate a link value + * + * This function translates a platform-specific link value to a link number. + * On Intel platforms, the link value is normally a offset into the PCI + * configuration space into the legacy bridge. + * + * Note: this function should be provided by the platform codes, as the + * implementation of interrupt router may be different. + * + * @dev: irq router's udevice + * @link: platform-specific link value + * @return: link number which represents a PIRQ + */ +int pirq_translate_link(struct udevice *dev, int link); + +/** + * pirq_assign_irq() - Assign an IRQ to a PIRQ link + * + * This function assigns the IRQ to a PIRQ link so that the PIRQ is routed to + * the 8259 PIC. + * + * Note: this function should be provided by the platform codes, as the + * implementation of interrupt router may be different. + * + * @dev: irq router's udevice + * @link: link number which represents a PIRQ + * @irq: IRQ to which the PIRQ is routed + */ +void pirq_assign_irq(struct udevice *dev, int link, u8 irq); + +/** + * pirq_route_irqs() - Route PIRQs to 8259 PIC + * + * This function configures all PCI devices' interrupt pins and maps them to + * PIRQs and finally 8259 PIC. The routed irq number is written to interrupt + * line register in the configuration space of the PCI device for OS to use. + * The configuration source is taken from a struct irq_info table, the format + * of which is defined in PIRQ routing table spec and PCI BIOS spec. + * + * @dev: irq router's udevice + * @irq: pointer to the base address of the struct irq_info + * @num: number of entries in the struct irq_info + */ +void pirq_route_irqs(struct udevice *dev, struct irq_info *irq, int num); + +/** + * copy_pirq_routing_table() - Copy a PIRQ routing table + * + * This helper function copies the given PIRQ routing table to a given address. + * Before copying, it does several sanity tests against the PIRQ routing table. + * It also fixes up the table checksum and align the given address to a 16 byte + * boundary to meet the PIRQ routing table spec requirements. + * + * @addr: address to store the copied PIRQ routing table + * @rt: pointer to the PIRQ routing table to copy from + * @return: end address of the copied PIRQ routing table + */ +u32 copy_pirq_routing_table(u32 addr, struct irq_routing_table *rt); + +#endif /* _PIRQ_ROUTING_H_ */ |