Commit afc7d20c authored by venkatesh.pallipadi@intel.com's avatar venkatesh.pallipadi@intel.com Committed by Ingo Molnar

x86 PAT: consolidate old memtype new memtype check into a function

Impact: cleanup

Move the new memtype old memtype allowed check to header so that is can be
shared by other users. Subsequent patch uses this in pat.c in remap_pfn_range()
code path. No functionality change in this patch.
Signed-off-by: default avatarVenkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: default avatarSuresh Siddha <suresh.b.siddha@intel.com>
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
parent a3670613
......@@ -341,6 +341,25 @@ static inline pgprot_t pgprot_modify(pgprot_t oldprot, pgprot_t newprot)
#define canon_pgprot(p) __pgprot(pgprot_val(p) & __supported_pte_mask)
static inline int is_new_memtype_allowed(unsigned long flags,
unsigned long new_flags)
{
/*
* Certain new memtypes are not allowed with certain
* requested memtype:
* - request is uncached, return cannot be write-back
* - request is write-combine, return cannot be write-back
*/
if ((flags == _PAGE_CACHE_UC_MINUS &&
new_flags == _PAGE_CACHE_WB) ||
(flags == _PAGE_CACHE_WC &&
new_flags == _PAGE_CACHE_WB)) {
return 0;
}
return 1;
}
#ifndef __ASSEMBLY__
/* Indicate that x86 has its own track and untrack pfn vma functions */
#define __HAVE_PFNMAP_TRACKING
......
......@@ -314,17 +314,7 @@ int pci_mmap_page_range(struct pci_dev *dev, struct vm_area_struct *vma,
return retval;
if (flags != new_flags) {
/*
* Do not fallback to certain memory types with certain
* requested type:
* - request is uncached, return cannot be write-back
* - request is uncached, return cannot be write-combine
* - request is write-combine, return cannot be write-back
*/
if ((flags == _PAGE_CACHE_UC_MINUS &&
(new_flags == _PAGE_CACHE_WB)) ||
(flags == _PAGE_CACHE_WC &&
new_flags == _PAGE_CACHE_WB)) {
if (!is_new_memtype_allowed(flags, new_flags)) {
free_memtype(addr, addr+len);
return -EINVAL;
}
......
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