linux/arch/x86/include/asm/io_apic.h
Suresh Siddha 0280f7c416 x86, x2apic: cleanup the IO-APIC level migration with interrupt-remapping
Impact: simplification

In the current code, for level triggered migration, we need to modify the
io-apic RTE with the update vector information, along with modifying interrupt
remapping table entry(IRTE) with vector and destination. This is to ensure that
remote IRR bit inthe IOAPIC RTE gets cleared when the cpu does EOI.

With this patch, for level triggered, we eliminate the io-apic RTE modification
(with the updated vector information), by using a virtual vector (io-apic pin
number).  Real vector that is used for interrupting cpu will be coming from
the interrupt-remapping table entry. Trigger mode in the IRTE will always be
edge, and the actual level or edge trigger will be setup in the IO-APIC RTE.
So a level triggered interrupt will appear as an edge to the local apic
cpu but still as level to the IO-APIC.

With this change, level irq migration can be done by simply modifying
the interrupt-remapping table entry with out changing the io-apic RTE.
And as the interrupt appears as edge at the cpu, in addition to do the
local apic EOI, we need to do IO-APIC directed EOI to clear the remote
IRR bit in  the IO-APIC RTE.

This simplies the irq migration in the presence of interrupt-remapping.

Idea-by: Rajesh Sankaran <rajesh.sankaran@intel.com>
Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2009-03-17 15:44:27 -07:00

187 lines
4.2 KiB
C

#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>
/*
* Intel IO-APIC support for SMP and UP systems.
*
* Copyright (C) 1997, 1998, 1999, 2000 Ingo Molnar
*/
/* I/O Unit Redirection Table */
#define IO_APIC_REDIR_VECTOR_MASK 0x000FF
#define IO_APIC_REDIR_DEST_LOGICAL 0x00800
#define IO_APIC_REDIR_DEST_PHYSICAL 0x00000
#define IO_APIC_REDIR_SEND_PENDING (1 << 12)
#define IO_APIC_REDIR_REMOTE_IRR (1 << 14)
#define IO_APIC_REDIR_LEVEL_TRIGGER (1 << 15)
#define IO_APIC_REDIR_MASKED (1 << 16)
/*
* 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;
};
enum ioapic_irq_destination_types {
dest_Fixed = 0,
dest_LowestPrio = 1,
dest_SMI = 2,
dest__reserved_1 = 3,
dest_NMI = 4,
dest_INIT = 5,
dest__reserved_2 = 6,
dest_ExtINT = 7
};
struct IO_APIC_route_entry {
__u32 vector : 8,
delivery_mode : 3, /* 000: FIXED
* 001: lowest prio
* 111: ExtINT
*/
dest_mode : 1, /* 0: physical, 1: logical */
delivery_status : 1,
polarity : 1,
irr : 1,
trigger : 1, /* 0: edge, 1: level */
mask : 1, /* 0: enabled, 1: disabled */
__reserved_2 : 15;
__u32 __reserved_3 : 24,
dest : 8;
} __attribute__ ((packed));
struct IR_IO_APIC_route_entry {
__u64 vector : 8,
zero : 3,
index2 : 1,
delivery_status : 1,
polarity : 1,
irr : 1,
trigger : 1,
mask : 1,
reserved : 31,
format : 1,
index : 15;
} __attribute__ ((packed));
#ifdef CONFIG_X86_IO_APIC
/*
* # of IO-APICs and # of IRQ routing registers
*/
extern int nr_ioapics;
extern int nr_ioapic_registers[MAX_IO_APICS];
#define MP_MAX_IOAPIC_PIN 127
/* I/O APIC entries */
extern struct mpc_ioapic mp_ioapics[MAX_IO_APICS];
/* # of MP IRQ source entries */
extern int mp_irq_entries;
/* MP IRQ source entries */
extern struct mpc_intsrc mp_irqs[MAX_IRQ_SOURCES];
/* non-0 if default (table-less) MP configuration */
extern int mpc_default_type;
/* Older SiS APIC requires we rewrite the index register */
extern int sis_apic_bug;
/* 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;
/* 1 if the timer IRQ uses the '8259A Virtual Wire' mode */
extern int timer_through_8259;
/*
* 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)
#ifdef CONFIG_ACPI
extern int io_apic_get_unique_id(int ioapic, int apic_id);
extern int io_apic_get_version(int ioapic);
extern int io_apic_get_redir_entries(int ioapic);
extern int io_apic_set_pci_routing(int ioapic, int pin, int irq,
int edge_level, int active_high_low);
#endif /* CONFIG_ACPI */
extern int (*ioapic_renumber_irq)(int ioapic, int irq);
extern void ioapic_init_mappings(void);
#ifdef CONFIG_X86_64
extern int save_mask_IO_APIC_setup(void);
extern void restore_IO_APIC_setup(void);
extern void reinit_intr_remapped_IO_APIC(int);
#endif
extern void probe_nr_irqs_gsi(void);
extern int setup_ioapic_entry(int apic, int irq,
struct IO_APIC_route_entry *entry,
unsigned int destination, int trigger,
int polarity, int vector, int pin);
extern void ioapic_write_entry(int apic, int pin,
struct IO_APIC_route_entry e);
#else /* !CONFIG_X86_IO_APIC */
#define io_apic_assign_pci_irqs 0
static const int timer_through_8259 = 0;
static inline void ioapic_init_mappings(void) { }
static inline void probe_nr_irqs_gsi(void) { }
#endif
#endif /* _ASM_X86_IO_APIC_H */