2017-02-09 09:49:03 -05:00

177 lines
6.0 KiB
C

/*
* Copyright (c) 2009
* The President and Fellows of Harvard College.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE UNIVERSITY AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE UNIVERSITY OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#ifndef _CPU_H_
#define _CPU_H_
#include <spinlock.h>
#include <threadlist.h>
#include <machine/vm.h> /* for TLBSHOOTDOWN_MAX */
/*
* Per-cpu structure
*
* Note: curcpu is defined by <current.h>.
*
* cpu->c_self should always be used when *using* the address of curcpu
* (as opposed to merely dereferencing it) in case curcpu is defined as
* a pointer with a fixed address and a per-cpu mapping in the MMU.
*/
struct cpu {
/*
* Fixed after allocation.
*/
struct cpu *c_self; /* Canonical address of this struct */
unsigned c_number; /* This cpu's cpu number */
unsigned c_hardware_number; /* Hardware-defined cpu number */
/*
* Accessed only by this cpu.
*/
struct thread *c_curthread; /* Current thread on cpu */
struct threadlist c_zombies; /* List of exited threads */
unsigned c_hardclocks; /* Counter of hardclock() calls */
unsigned c_spinlocks; /* Counter of spinlocks held */
/*
* Accessed by other cpus.
* Protected by the runqueue lock.
*/
bool c_isidle; /* True if this cpu is idle */
struct threadlist c_runqueue; /* Run queue for this cpu */
struct spinlock c_runqueue_lock;
/*
* Accessed by other cpus.
* Protected by the IPI lock.
*
* TLB shootdown requests made to this CPU are queued in
* c_shootdown[], with c_numshootdown holding the number of
* requests. TLBSHOOTDOWN_MAX is the maximum number that can
* be queued at once, which is machine-dependent.
*
* The contents of struct tlbshootdown are also machine-
* dependent and might reasonably be either an address space
* and vaddr pair, or a paddr, or something else.
*/
uint32_t c_ipi_pending; /* One bit for each IPI number */
struct tlbshootdown c_shootdown[TLBSHOOTDOWN_MAX];
unsigned c_numshootdown;
struct spinlock c_ipi_lock;
/*
* Accessed by other cpus. Protected inside hangman.c.
*/
HANGMAN_ACTOR(c_hangman);
};
/*
* Initialization functions.
*
* cpu_create creates a cpu; it is suitable for calling from driver-
* or bus-specific code that looks for secondary CPUs.
*
* cpu_create calls cpu_machdep_init.
*
* cpu_start_secondary is the platform-dependent assembly language
* entry point for new CPUs; it can be found in start.S. It calls
* cpu_hatch after having claimed the startup stack and thread created
* for the cpu.
*/
struct cpu *cpu_create(unsigned hardware_number);
void cpu_machdep_init(struct cpu *);
/*ASMLINKAGE*/ void cpu_start_secondary(void);
void cpu_hatch(unsigned software_number);
/*
* Produce a string describing the CPU type.
*/
void cpu_identify(char *buf, size_t max);
/*
* Hardware-level interrupt on/off, for the current CPU.
*
* These should only be used by the spl code.
*/
void cpu_irqoff(void);
void cpu_irqon(void);
/*
* Idle or shut down (respectively) the processor.
*
* cpu_idle() sits around (in a low-power state if possible) until it
* thinks something interesting may have happened, such as an
* interrupt. Then it returns. (It may be wrong, so it should always
* be called in a loop checking some other condition.) It must be
* called with interrupts off to avoid race conditions, although
* interrupts may be delivered before it returns.
*
* cpu_halt sits around (in a low-power state if possible) until the
* external reset is pushed. Interrupts should be disabled. It does
* not return. It should not allow interrupts to be delivered.
*/
void cpu_idle(void);
void cpu_halt(void);
/*
* Interprocessor interrupts.
*
* From time to time it is necessary to poke another CPU. System
* boards of multiprocessor machines provide a way to do this.
*
* TLB shootdown is done by the VM system when more than one processor
* has (or may have) a page mapped in the MMU and it is being changed
* or otherwise needs to be invalidated across all CPUs.
*
* ipi_send sends an IPI to one CPU.
* ipi_broadcast sends an IPI to all CPUs except the current one.
* ipi_tlbshootdown is like ipi_send but carries TLB shootdown data.
*
* interprocessor_interrupt is called on the target CPU when an IPI is
* received.
*/
/* IPI types */
#define IPI_PANIC 0 /* System has called panic() */
#define IPI_OFFLINE 1 /* CPU is requested to go offline */
#define IPI_UNIDLE 2 /* Runnable threads are available */
#define IPI_TLBSHOOTDOWN 3 /* MMU mapping(s) need invalidation */
void ipi_send(struct cpu *target, int code);
void ipi_broadcast(int code);
void ipi_tlbshootdown(struct cpu *target, const struct tlbshootdown *mapping);
void interprocessor_interrupt(void);
#endif /* _CPU_H_ */