70 lines
2.2 KiB
C
70 lines
2.2 KiB
C
/*
|
|
* Copyright © 2008 Ingo Molnar
|
|
*
|
|
* This program is free software; you can redistribute it and/or modify
|
|
* it under the terms of the GNU General Public License as published by
|
|
* the Free Software Foundation; either version 2 of the License, or
|
|
* (at your option) any later version.
|
|
*
|
|
* This program is distributed in the hope that it will be useful, but
|
|
* WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
|
|
* General Public License for more details.
|
|
*
|
|
* You should have received a copy of the GNU General Public License along
|
|
* with this program; if not, write to the Free Software Foundation, Inc.,
|
|
* 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
|
|
*/
|
|
|
|
#include <asm/iomap.h>
|
|
#include <asm/pat.h>
|
|
#include <linux/module.h>
|
|
|
|
/* Map 'pfn' using fixed map 'type' and protections 'prot'
|
|
*/
|
|
void *
|
|
iomap_atomic_prot_pfn(unsigned long pfn, enum km_type type, pgprot_t prot)
|
|
{
|
|
enum fixed_addresses idx;
|
|
unsigned long vaddr;
|
|
|
|
pagefault_disable();
|
|
|
|
/*
|
|
* For non-PAT systems, promote PAGE_KERNEL_WC to PAGE_KERNEL_UC_MINUS.
|
|
* PAGE_KERNEL_WC maps to PWT, which translates to uncached if the
|
|
* MTRR is UC or WC. UC_MINUS gets the real intention, of the
|
|
* user, which is "WC if the MTRR is WC, UC if you can't do that."
|
|
*/
|
|
if (!pat_enabled && pgprot_val(prot) == pgprot_val(PAGE_KERNEL_WC))
|
|
prot = PAGE_KERNEL_UC_MINUS;
|
|
|
|
idx = type + KM_TYPE_NR*smp_processor_id();
|
|
vaddr = __fix_to_virt(FIX_KMAP_BEGIN + idx);
|
|
set_pte(kmap_pte-idx, pfn_pte(pfn, prot));
|
|
arch_flush_lazy_mmu_mode();
|
|
|
|
return (void*) vaddr;
|
|
}
|
|
EXPORT_SYMBOL_GPL(iomap_atomic_prot_pfn);
|
|
|
|
void
|
|
iounmap_atomic(void *kvaddr, enum km_type type)
|
|
{
|
|
unsigned long vaddr = (unsigned long) kvaddr & PAGE_MASK;
|
|
enum fixed_addresses idx = type + KM_TYPE_NR*smp_processor_id();
|
|
|
|
/*
|
|
* Force other mappings to Oops if they'll try to access this pte
|
|
* without first remap it. Keeping stale mappings around is a bad idea
|
|
* also, in case the page changes cacheability attributes or becomes
|
|
* a protected page in a hypervisor.
|
|
*/
|
|
if (vaddr == __fix_to_virt(FIX_KMAP_BEGIN+idx))
|
|
kpte_clear_flush(kmap_pte-idx, vaddr);
|
|
|
|
arch_flush_lazy_mmu_mode();
|
|
pagefault_enable();
|
|
}
|
|
EXPORT_SYMBOL_GPL(iounmap_atomic);
|