// SPDX-License-Identifier: GPL-2.0-or-later
|
/*
|
* Copyright © 2008 Ingo Molnar
|
*/
|
|
#include <asm/iomap.h>
|
#include <asm/memtype.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 = memtype_reserve_io(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)
|
{
|
memtype_free_io(base, base + size);
|
}
|
EXPORT_SYMBOL_GPL(iomap_free);
|
|
void __iomem *__iomap_local_pfn_prot(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_local_pfn_prot(pfn, prot);
|
}
|
EXPORT_SYMBOL_GPL(__iomap_local_pfn_prot);
|
