mirror of https://gitee.com/openkylin/linux.git
130 lines
3.7 KiB
C
130 lines
3.7 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/export.h>
|
|
#include <linux/highmem.h>
|
|
|
|
static int is_io_mapping_possible(resource_size_t base, unsigned long size)
|
|
{
|
|
#if !defined(CONFIG_X86_PAE) && defined(CONFIG_PHYS_ADDR_T_64BIT)
|
|
/* There is no way to map greater than 1 << 32 address without PAE */
|
|
if (base + size > 0x100000000ULL)
|
|
return 0;
|
|
#endif
|
|
return 1;
|
|
}
|
|
|
|
int iomap_create_wc(resource_size_t base, unsigned long size, pgprot_t *prot)
|
|
{
|
|
enum page_cache_mode pcm = _PAGE_CACHE_MODE_WC;
|
|
int ret;
|
|
|
|
if (!is_io_mapping_possible(base, size))
|
|
return -EINVAL;
|
|
|
|
ret = io_reserve_memtype(base, base + size, &pcm);
|
|
if (ret)
|
|
return ret;
|
|
|
|
*prot = __pgprot(__PAGE_KERNEL | cachemode2protval(pcm));
|
|
/* Filter out unsupported __PAGE_KERNEL* bits: */
|
|
pgprot_val(*prot) &= __default_kernel_pte_mask;
|
|
|
|
return 0;
|
|
}
|
|
EXPORT_SYMBOL_GPL(iomap_create_wc);
|
|
|
|
void iomap_free(resource_size_t base, unsigned long size)
|
|
{
|
|
io_free_memtype(base, base + size);
|
|
}
|
|
EXPORT_SYMBOL_GPL(iomap_free);
|
|
|
|
void *kmap_atomic_prot_pfn(unsigned long pfn, pgprot_t prot)
|
|
{
|
|
unsigned long vaddr;
|
|
int idx, type;
|
|
|
|
preempt_disable();
|
|
pagefault_disable();
|
|
|
|
type = kmap_atomic_idx_push();
|
|
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;
|
|
}
|
|
|
|
/*
|
|
* Map 'pfn' using protections 'prot'
|
|
*/
|
|
void __iomem *
|
|
iomap_atomic_prot_pfn(unsigned long pfn, pgprot_t prot)
|
|
{
|
|
/*
|
|
* For non-PAT systems, translate non-WB request to UC- just in
|
|
* case the caller set the PWT bit to prot directly without using
|
|
* pgprot_writecombine(). UC- translates to uncached if the MTRR
|
|
* is UC or WC. UC- 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() && pgprot2cachemode(prot) != _PAGE_CACHE_MODE_WB)
|
|
prot = __pgprot(__PAGE_KERNEL |
|
|
cachemode2protval(_PAGE_CACHE_MODE_UC_MINUS));
|
|
|
|
/* Filter out unsupported __PAGE_KERNEL* bits: */
|
|
pgprot_val(prot) &= __default_kernel_pte_mask;
|
|
|
|
return (void __force __iomem *) kmap_atomic_prot_pfn(pfn, prot);
|
|
}
|
|
EXPORT_SYMBOL_GPL(iomap_atomic_prot_pfn);
|
|
|
|
void
|
|
iounmap_atomic(void __iomem *kvaddr)
|
|
{
|
|
unsigned long vaddr = (unsigned long) kvaddr & PAGE_MASK;
|
|
|
|
if (vaddr >= __fix_to_virt(FIX_KMAP_END) &&
|
|
vaddr <= __fix_to_virt(FIX_KMAP_BEGIN)) {
|
|
int idx, type;
|
|
|
|
type = kmap_atomic_idx();
|
|
idx = type + KM_TYPE_NR * smp_processor_id();
|
|
|
|
#ifdef CONFIG_DEBUG_HIGHMEM
|
|
WARN_ON_ONCE(vaddr != __fix_to_virt(FIX_KMAP_BEGIN + idx));
|
|
#endif
|
|
/*
|
|
* 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.
|
|
*/
|
|
kpte_clear_flush(kmap_pte-idx, vaddr);
|
|
kmap_atomic_idx_pop();
|
|
}
|
|
|
|
pagefault_enable();
|
|
preempt_enable();
|
|
}
|
|
EXPORT_SYMBOL_GPL(iounmap_atomic);
|