Commit 2520bd31 authored by venkatesh.pallipadi@intel.com's avatar venkatesh.pallipadi@intel.com Committed by H. Peter Anvin

x86: PAT: add pgprot_writecombine() interface for drivers - v3

Impact: New mm functionality.

Add pgprot_writecombine. pgprot_writecombine will be aliased to
pgprot_noncached when not supported by the architecture.
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 avatarH. Peter Anvin <hpa@zytor.com>
parent 8a7b12f7
......@@ -168,6 +168,9 @@
#ifndef __ASSEMBLY__
#define pgprot_writecombine pgprot_writecombine
extern pgprot_t pgprot_writecombine(pgprot_t prot);
/*
* ZERO_PAGE is a global shared page that is always zero: used
* for zero-mapped memory areas etc..
......
......@@ -832,6 +832,14 @@ void untrack_pfn_vma(struct vm_area_struct *vma, unsigned long pfn,
}
}
pgprot_t pgprot_writecombine(pgprot_t prot)
{
if (pat_enabled)
return __pgprot(pgprot_val(prot) | _PAGE_CACHE_WC);
else
return pgprot_noncached(prot);
}
#if defined(CONFIG_DEBUG_FS) && defined(CONFIG_X86_PAT)
/* get Nth element of the linked list */
......
......@@ -129,6 +129,10 @@ static inline void ptep_set_wrprotect(struct mm_struct *mm, unsigned long addres
#define move_pte(pte, prot, old_addr, new_addr) (pte)
#endif
#ifndef pgprot_writecombine
#define pgprot_writecombine pgprot_noncached
#endif
/*
* When walking page tables, get the address of the next boundary,
* or the end address of the range if that comes earlier. Although no
......
Markdown is supported
0%
or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment