freebsd-skq/sys/mips/include/pcpu.h
Neel Natu 9dd3fbb0f2 Provide access to pcpu structures for SMP kernels.
The basic idea is to use a the same virtual address as a window onto
distinct physical memory locations - one per processor. The physical
address that you access through this mapping depends on which cpu you
are currently executing on. We can now use the same virtual address
on any processor to access its per-cpu area.

The details are:

- The virtual address for 'struct pcpu *pcpup' is obtained by
  stealing 2 pages worth of KVA in pmap_bootstrap().

- The mapping from the constant virtual address to a distinct
  physical page is done in cpu_pcpu_init() through a wired TLB entry.

- A side-effect of this is that we reserve 2 pages worth of memory
  for the pcpu but in reality it needs much less than that. The unused
  memory is now used as the boot stack for the BSP and APs.

Remove SMP-specific bits from locore.S. The plan is to use a separate
mpboot.S for AP bootstrap.

Discussed on: freebsd-mips

Approved by: imp (mentor)
2010-01-30 01:54:29 +00:00

61 lines
2.4 KiB
C

/*-
* Copyright (c) 1999 Luoqi Chen <luoqi@freebsd.org>
* Copyright (c) Peter Wemm <peter@netplex.com.au>
* All rights reserved.
*
* 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.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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.
*
* from: src/sys/alpha/include/pcpu.h,v 1.15 2004/11/05 19:16:44 jhb
* $FreeBSD$
*/
#ifndef _MACHINE_PCPU_H_
#define _MACHINE_PCPU_H_
#include <machine/pte.h>
#define PCPU_MD_FIELDS \
pd_entry_t *pc_segbase; /* curthread segbase */ \
struct pmap *pc_curpmap; /* pmap of curthread */ \
u_int32_t pc_next_asid; /* next ASID to alloc */ \
u_int32_t pc_asid_generation; /* current ASID generation */ \
u_int pc_pending_ipis; /* IPIs pending to this CPU */
#ifdef _KERNEL
extern char pcpu_space[MAXCPU][PAGE_SIZE * 2];
#define PCPU_ADDR(cpu) (struct pcpu *)(pcpu_space[(cpu)])
extern struct pcpu *pcpup;
#define PCPUP pcpup
#define PCPU_ADD(member, value) (PCPUP->pc_ ## member += (value))
#define PCPU_GET(member) (PCPUP->pc_ ## member)
#define PCPU_INC(member) PCPU_ADD(member, 1)
#define PCPU_PTR(member) (&PCPUP->pc_ ## member)
#define PCPU_SET(member,value) (PCPUP->pc_ ## member = (value))
#define PCPU_LAZY_INC(member) (++PCPUP->pc_ ## member)
#endif /* _KERNEL */
#endif /* !_MACHINE_PCPU_H_ */