/*
* Map 'pfn' using fixed map 'type' and protections 'prot'
*/
void *
iomap_atomic_prot_pfn(unsigned long pfn, enum km_type type, pgprot_t prot)
{
/*
* 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;
return kmap_atomic_prot_pfn(pfn, type, prot);
}
/*
* 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));
return (void __force __iomem *) kmap_atomic_prot_pfn(pfn, prot);
}
/*
* Map 'pfn' using protections 'prot'
*/
void __iomem *
iomap_atomic_prot_pfn(unsigned long pfn, pgprot_t prot)
{
/*
* 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) ==
(__PAGE_KERNEL | cachemode2protval(_PAGE_CACHE_MODE_WC)))
prot = __pgprot(__PAGE_KERNEL |
cachemode2protval(_PAGE_CACHE_MODE_UC_MINUS));
return (void __force __iomem *) kmap_atomic_prot_pfn(pfn, prot);
}
/*
* This is the same as kmap_atomic() but can map memory that doesn't
* have a struct page associated with it.
*/
void *kmap_atomic_pfn(unsigned long pfn)
{
return kmap_atomic_prot_pfn(pfn, kmap_prot);
}
/*
* This is the same as kmap_atomic() but can map memory that doesn't
* have a struct page associated with it.
*/
void *kmap_atomic_pfn(unsigned long pfn, enum km_type type)
{
return kmap_atomic_prot_pfn(pfn, type, kmap_prot);
}
