linux/arch/x86/include/asm/io_apic.h
David Woodhouse 51130d2188 x86/ioapic: Handle Extended Destination ID field in RTE
Bits 63-48 of the I/OAPIC Redirection Table Entry map directly to bits 19-4
of the address used in the resulting MSI cycle.

Historically, the x86 MSI format only used the top 8 of those 16 bits as
the destination APIC ID, and the "Extended Destination ID" in the lower 8
bits was unused.

With interrupt remapping, the lowest bit of the Extended Destination ID
(bit 48 of RTE, bit 4 of MSI address) is now used to indicate a remappable
format MSI.

A hypervisor can use the other 7 bits of the Extended Destination ID to
permit guests to address up to 15 bits of APIC IDs, thus allowing 32768
vCPUs before having to expose a vIOMMU and interrupt remapping to the
guest.

No behavioural change in this patch, since nothing yet permits APIC IDs
above 255 to be used with the non-IR I/OAPIC domain.

[ tglx: Converted it to the cleaned up entry/msi_msg format and added
  	commentry ]

Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20201024213535.443185-32-dwmw2@infradead.org
2020-10-28 20:26:28 +01:00

219 lines
5.1 KiB
C

/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _ASM_X86_IO_APIC_H
#define _ASM_X86_IO_APIC_H
#include <linux/types.h>
#include <asm/mpspec.h>
#include <asm/apicdef.h>
#include <asm/irq_vectors.h>
#include <asm/x86_init.h>
/*
* Intel IO-APIC support for SMP and UP systems.
*
* Copyright (C) 1997, 1998, 1999, 2000 Ingo Molnar
*/
/*
* The structure of the IO-APIC:
*/
union IO_APIC_reg_00 {
u32 raw;
struct {
u32 __reserved_2 : 14,
LTS : 1,
delivery_type : 1,
__reserved_1 : 8,
ID : 8;
} __attribute__ ((packed)) bits;
};
union IO_APIC_reg_01 {
u32 raw;
struct {
u32 version : 8,
__reserved_2 : 7,
PRQ : 1,
entries : 8,
__reserved_1 : 8;
} __attribute__ ((packed)) bits;
};
union IO_APIC_reg_02 {
u32 raw;
struct {
u32 __reserved_2 : 24,
arbitration : 4,
__reserved_1 : 4;
} __attribute__ ((packed)) bits;
};
union IO_APIC_reg_03 {
u32 raw;
struct {
u32 boot_DT : 1,
__reserved_1 : 31;
} __attribute__ ((packed)) bits;
};
struct IO_APIC_route_entry {
union {
struct {
u64 vector : 8,
delivery_mode : 3,
dest_mode_logical : 1,
delivery_status : 1,
active_low : 1,
irr : 1,
is_level : 1,
masked : 1,
reserved_0 : 15,
reserved_1 : 17,
virt_destid_8_14 : 7,
destid_0_7 : 8;
};
struct {
u64 ir_shared_0 : 8,
ir_zero : 3,
ir_index_15 : 1,
ir_shared_1 : 5,
ir_reserved_0 : 31,
ir_format : 1,
ir_index_0_14 : 15;
};
struct {
u64 w1 : 32,
w2 : 32;
};
};
} __attribute__ ((packed));
struct irq_alloc_info;
struct ioapic_domain_cfg;
#define IOAPIC_MAP_ALLOC 0x1
#define IOAPIC_MAP_CHECK 0x2
#ifdef CONFIG_X86_IO_APIC
/*
* # of IO-APICs and # of IRQ routing registers
*/
extern int nr_ioapics;
extern int mpc_ioapic_id(int ioapic);
extern unsigned int mpc_ioapic_addr(int ioapic);
/* # of MP IRQ source entries */
extern int mp_irq_entries;
/* MP IRQ source entries */
extern struct mpc_intsrc mp_irqs[MAX_IRQ_SOURCES];
/* 1 if "noapic" boot option passed */
extern int skip_ioapic_setup;
/* 1 if "noapic" boot option passed */
extern int noioapicquirk;
/* -1 if "noapic" boot option passed */
extern int noioapicreroute;
extern u32 gsi_top;
extern unsigned long io_apic_irqs;
#define IO_APIC_IRQ(x) (((x) >= NR_IRQS_LEGACY) || ((1 << (x)) & io_apic_irqs))
/*
* If we use the IO-APIC for IRQ routing, disable automatic
* assignment of PCI IRQ's.
*/
#define io_apic_assign_pci_irqs \
(mp_irq_entries && !skip_ioapic_setup && io_apic_irqs)
struct irq_cfg;
extern void ioapic_insert_resources(void);
extern int arch_early_ioapic_init(void);
extern int save_ioapic_entries(void);
extern void mask_ioapic_entries(void);
extern int restore_ioapic_entries(void);
extern void setup_ioapic_ids_from_mpc(void);
extern void setup_ioapic_ids_from_mpc_nocheck(void);
extern int mp_find_ioapic(u32 gsi);
extern int mp_find_ioapic_pin(int ioapic, u32 gsi);
extern int mp_map_gsi_to_irq(u32 gsi, unsigned int flags,
struct irq_alloc_info *info);
extern void mp_unmap_irq(int irq);
extern int mp_register_ioapic(int id, u32 address, u32 gsi_base,
struct ioapic_domain_cfg *cfg);
extern int mp_unregister_ioapic(u32 gsi_base);
extern int mp_ioapic_registered(u32 gsi_base);
extern void ioapic_set_alloc_attr(struct irq_alloc_info *info,
int node, int trigger, int polarity);
extern void mp_save_irq(struct mpc_intsrc *m);
extern void disable_ioapic_support(void);
extern void __init io_apic_init_mappings(void);
extern unsigned int native_io_apic_read(unsigned int apic, unsigned int reg);
extern void native_restore_boot_irq_mode(void);
static inline unsigned int io_apic_read(unsigned int apic, unsigned int reg)
{
return x86_apic_ops.io_apic_read(apic, reg);
}
extern void setup_IO_APIC(void);
extern void enable_IO_APIC(void);
extern void clear_IO_APIC(void);
extern void restore_boot_irq_mode(void);
extern int IO_APIC_get_PCI_irq_vector(int bus, int devfn, int pin);
extern void print_IO_APICs(void);
#else /* !CONFIG_X86_IO_APIC */
#define IO_APIC_IRQ(x) 0
#define io_apic_assign_pci_irqs 0
#define setup_ioapic_ids_from_mpc x86_init_noop
static inline void ioapic_insert_resources(void) { }
static inline int arch_early_ioapic_init(void) { return 0; }
static inline void print_IO_APICs(void) {}
#define gsi_top (NR_IRQS_LEGACY)
static inline int mp_find_ioapic(u32 gsi) { return 0; }
static inline int mp_map_gsi_to_irq(u32 gsi, unsigned int flags,
struct irq_alloc_info *info)
{
return gsi;
}
static inline void mp_unmap_irq(int irq) { }
static inline int save_ioapic_entries(void)
{
return -ENOMEM;
}
static inline void mask_ioapic_entries(void) { }
static inline int restore_ioapic_entries(void)
{
return -ENOMEM;
}
static inline void mp_save_irq(struct mpc_intsrc *m) { }
static inline void disable_ioapic_support(void) { }
static inline void io_apic_init_mappings(void) { }
#define native_io_apic_read NULL
#define native_restore_boot_irq_mode NULL
static inline void setup_IO_APIC(void) { }
static inline void enable_IO_APIC(void) { }
static inline void restore_boot_irq_mode(void) { }
#endif
#endif /* _ASM_X86_IO_APIC_H */