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// 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_atomic_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;
preempt_disable();
pagefault_disable();
return (void __force __iomem *)__kmap_local_pfn_prot(pfn, prot);
}
EXPORT_SYMBOL_GPL(iomap_atomic_pfn_prot);
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