alistair23-linux/arch/i386/mm/boot_ioremap.c
Rusty Russell da181a8b39 [PATCH] paravirt: Add MMU virtualization to paravirt_ops
Add the three bare TLB accessor functions to paravirt-ops.  Most amusingly,
flush_tlb is redefined on SMP, so I can't call the paravirt op flush_tlb.
Instead, I chose to indicate the actual flush type, kernel (global) vs. user
(non-global).  Global in this sense means using the global bit in the page
table entry, which makes TLB entries persistent across CR3 reloads, not
global as in the SMP sense of invoking remote shootdowns, so the term is
confusingly overloaded.

AK: folded in fix from Zach for PAE compilation

Signed-off-by: Zachary Amsden <zach@vmware.com>
Signed-off-by: Chris Wright <chrisw@sous-sol.org>
Signed-off-by: Andi Kleen <ak@suse.de>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Jeremy Fitzhardinge <jeremy@goop.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
2006-12-07 02:14:08 +01:00

101 lines
2.8 KiB
C

/*
* arch/i386/mm/boot_ioremap.c
*
* Re-map functions for early boot-time before paging_init() when the
* boot-time pagetables are still in use
*
* Written by Dave Hansen <haveblue@us.ibm.com>
*/
/*
* We need to use the 2-level pagetable functions, but CONFIG_X86_PAE
* keeps that from happenning. If anyone has a better way, I'm listening.
*
* boot_pte_t is defined only if this all works correctly
*/
#undef CONFIG_X86_PAE
#undef CONFIG_PARAVIRT
#include <asm/page.h>
#include <asm/pgtable.h>
#include <asm/tlbflush.h>
#include <linux/init.h>
#include <linux/stddef.h>
/*
* I'm cheating here. It is known that the two boot PTE pages are
* allocated next to each other. I'm pretending that they're just
* one big array.
*/
#define BOOT_PTE_PTRS (PTRS_PER_PTE*2)
static unsigned long boot_pte_index(unsigned long vaddr)
{
return __pa(vaddr) >> PAGE_SHIFT;
}
static inline boot_pte_t* boot_vaddr_to_pte(void *address)
{
boot_pte_t* boot_pg = (boot_pte_t*)pg0;
return &boot_pg[boot_pte_index((unsigned long)address)];
}
/*
* This is only for a caller who is clever enough to page-align
* phys_addr and virtual_source, and who also has a preference
* about which virtual address from which to steal ptes
*/
static void __boot_ioremap(unsigned long phys_addr, unsigned long nrpages,
void* virtual_source)
{
boot_pte_t* pte;
int i;
char *vaddr = virtual_source;
pte = boot_vaddr_to_pte(virtual_source);
for (i=0; i < nrpages; i++, phys_addr += PAGE_SIZE, pte++) {
set_pte(pte, pfn_pte(phys_addr>>PAGE_SHIFT, PAGE_KERNEL));
__flush_tlb_one(&vaddr[i*PAGE_SIZE]);
}
}
/* the virtual space we're going to remap comes from this array */
#define BOOT_IOREMAP_PAGES 4
#define BOOT_IOREMAP_SIZE (BOOT_IOREMAP_PAGES*PAGE_SIZE)
static __initdata char boot_ioremap_space[BOOT_IOREMAP_SIZE]
__attribute__ ((aligned (PAGE_SIZE)));
/*
* This only applies to things which need to ioremap before paging_init()
* bt_ioremap() and plain ioremap() are both useless at this point.
*
* When used, we're still using the boot-time pagetables, which only
* have 2 PTE pages mapping the first 8MB
*
* There is no unmap. The boot-time PTE pages aren't used after boot.
* If you really want the space back, just remap it yourself.
* boot_ioremap(&ioremap_space-PAGE_OFFSET, BOOT_IOREMAP_SIZE)
*/
__init void* boot_ioremap(unsigned long phys_addr, unsigned long size)
{
unsigned long last_addr, offset;
unsigned int nrpages;
last_addr = phys_addr + size - 1;
/* page align the requested address */
offset = phys_addr & ~PAGE_MASK;
phys_addr &= PAGE_MASK;
size = PAGE_ALIGN(last_addr) - phys_addr;
nrpages = size >> PAGE_SHIFT;
if (nrpages > BOOT_IOREMAP_PAGES)
return NULL;
__boot_ioremap(phys_addr, nrpages, boot_ioremap_space);
return &boot_ioremap_space[offset];
}