2015-12-23 00:50:04 +00:00

130 lines
4.7 KiB
C

/*
* Copyright (c) 2000, 2001, 2002, 2003, 2004, 2005, 2008, 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 _MIPS_VM_H_
#define _MIPS_VM_H_
/*
* Machine-dependent VM system definitions.
*/
#define PAGE_SIZE 4096 /* size of VM page */
#define PAGE_FRAME 0xfffff000 /* mask for getting page number from addr */
/*
* MIPS-I hardwired memory layout:
* 0xc0000000 - 0xffffffff kseg2 (kernel, tlb-mapped)
* 0xa0000000 - 0xbfffffff kseg1 (kernel, unmapped, uncached)
* 0x80000000 - 0x9fffffff kseg0 (kernel, unmapped, cached)
* 0x00000000 - 0x7fffffff kuseg (user, tlb-mapped)
*
* (mips32 is a little different)
*/
#define MIPS_KUSEG 0x00000000
#define MIPS_KSEG0 0x80000000
#define MIPS_KSEG1 0xa0000000
#define MIPS_KSEG2 0xc0000000
/*
* The first 512 megs of physical space can be addressed in both kseg0 and
* kseg1. We use kseg0 for the kernel. This macro returns the kernel virtual
* address of a given physical address within that range. (We assume we're
* not using systems with more physical space than that anyway.)
*
* N.B. If you, say, call a function that returns a paddr or 0 on error,
* check the paddr for being 0 *before* you use this macro. While paddr 0
* is not legal for memory allocation or memory management (it holds
* exception handler code) when converted to a vaddr it's *not* NULL, *is*
* a valid address, and will make a *huge* mess if you scribble on it.
*/
#define PADDR_TO_KVADDR(paddr) ((paddr)+MIPS_KSEG0)
/*
* The top of user space. (Actually, the address immediately above the
* last valid user address.)
*/
#define USERSPACETOP MIPS_KSEG0
/*
* The starting value for the stack pointer at user level. Because
* the stack is subtract-then-store, this can start as the next
* address after the stack area.
*
* We put the stack at the very top of user virtual memory because it
* grows downwards.
*/
#define USERSTACK USERSPACETOP
/*
* Interface to the low-level module that looks after the amount of
* physical memory we have.
*
* ram_getsize returns one past the highest valid physical
* address. (This value is page-aligned.) The extant RAM ranges from
* physical address 0 up to but not including this address.
*
* ram_getfirstfree returns the lowest valid physical address. (It is
* also page-aligned.) Memory at this address and above is available
* for use during operation, and excludes the space the kernel is
* loaded into and memory that is grabbed in the very early stages of
* bootup. Memory below this address is already in use and should be
* reserved or otherwise not managed by the VM system. It should be
* called exactly once when the VM system initializes to take over
* management of physical memory.
*
* ram_stealmem can be used before ram_getsize is called to allocate
* memory that cannot be freed later. This is intended for use early
* in bootup before VM initialization is complete.
*/
void ram_bootstrap(void);
paddr_t ram_stealmem(unsigned long npages);
paddr_t ram_getsize(void);
paddr_t ram_getfirstfree(void);
/*
* TLB shootdown bits.
*
* We'll take up to 16 invalidations before just flushing the whole TLB.
*/
struct tlbshootdown {
/*
* Change this to what you need for your VM design.
*/
int ts_placeholder;
};
#define TLBSHOOTDOWN_MAX 16
#endif /* _MIPS_VM_H_ */