x86/mm/pat: Remove pat_enabled() checks

Now that we emulate a PAT table when PAT is disabled, there's no
need for those checks anymore as the PAT abstraction will handle
those cases too.

Based on a conglomerate patch from Toshi Kani.

Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Toshi Kani <toshi.kani@hp.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Elliott@hp.com
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Luis R. Rodriguez <mcgrof@suse.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: arnd@arndb.de
Cc: hch@lst.de
Cc: hmh@hmh.eng.br
Cc: jgross@suse.com
Cc: konrad.wilk@oracle.com
Cc: linux-mm <linux-mm@kvack.org>
Cc: linux-nvdimm@lists.01.org
Cc: stefan.bader@canonical.com
Cc: yigal@plexistor.com
Link: http://lkml.kernel.org/r/1433436928-31903-4-git-send-email-bp@alien8.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>

diff --git a/arch/x86/mm/iomap_32.c b/arch/x86/mm/iomap_32.c
index 3a2ec8790ca77cbf69fccd240ce0f19d62009a6e..a9dc7a37e6a2e05423d2caf7f524b5d7f1c34865 100644 (file)
--- a/arch/x86/mm/iomap_32.c
+++ b/arch/x86/mm/iomap_32.c
@@ -77,13 +77,13 @@ 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."
+        * 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() && pgprot_val(prot) ==
-           (__PAGE_KERNEL | cachemode2protval(_PAGE_CACHE_MODE_WC)))
+       if (!pat_enabled() && pgprot2cachemode(prot) != _PAGE_CACHE_MODE_WB)
                prot = __pgprot(__PAGE_KERNEL |
                                cachemode2protval(_PAGE_CACHE_MODE_UC_MINUS));
 

diff --git a/arch/x86/mm/ioremap.c b/arch/x86/mm/ioremap.c
index b0da3588b452de743928b15cdacde58f146adcd0..cc0f17c5ad9fdd597d19669418688e1110612f16 100644 (file)
--- a/arch/x86/mm/ioremap.c
+++ b/arch/x86/mm/ioremap.c
@@ -292,11 +292,8 @@ EXPORT_SYMBOL_GPL(ioremap_uc);
  */
 void __iomem *ioremap_wc(resource_size_t phys_addr, unsigned long size)
 {
-       if (pat_enabled())
-               return __ioremap_caller(phys_addr, size, _PAGE_CACHE_MODE_WC,
+       return __ioremap_caller(phys_addr, size, _PAGE_CACHE_MODE_WC,
                                        __builtin_return_address(0));
-       else
-               return ioremap_nocache(phys_addr, size);
 }
 EXPORT_SYMBOL(ioremap_wc);
 

diff --git a/arch/x86/mm/pageattr.c b/arch/x86/mm/pageattr.c
index fae3c5366ac08e6659d065199143b03ffbe29563..31b4f3fd1207406d0c68f809df4a3a1773400d04 100644 (file)
--- a/arch/x86/mm/pageattr.c
+++ b/arch/x86/mm/pageattr.c
@@ -1572,9 +1572,6 @@ int set_memory_wc(unsigned long addr, int numpages)
 {
        int ret;
 
-       if (!pat_enabled())
-               return set_memory_uc(addr, numpages);
-
        ret = reserve_memtype(__pa(addr), __pa(addr) + numpages * PAGE_SIZE,
                _PAGE_CACHE_MODE_WC, NULL);
        if (ret)

diff --git a/arch/x86/mm/pat.c b/arch/x86/mm/pat.c
index 6dc7826e4797fd656ea9c19765c6fac8788ed848..f89e460c55a8b6303f6704e7785890e5b7e8bdd0 100644 (file)
--- a/arch/x86/mm/pat.c
+++ b/arch/x86/mm/pat.c
@@ -438,12 +438,8 @@ int reserve_memtype(u64 start, u64 end, enum page_cache_mode req_type,
 
        if (!pat_enabled()) {
                /* This is identical to page table setting without PAT */
-               if (new_type) {
-                       if (req_type == _PAGE_CACHE_MODE_WC)
-                               *new_type = _PAGE_CACHE_MODE_UC_MINUS;
-                       else
-                               *new_type = req_type;
-               }
+               if (new_type)
+                       *new_type = req_type;
                return 0;
        }
 
@@ -947,11 +943,8 @@ void untrack_pfn(struct vm_area_struct *vma, unsigned long pfn,
 
 pgprot_t pgprot_writecombine(pgprot_t prot)
 {
-       if (pat_enabled())
-               return __pgprot(pgprot_val(prot) |
+       return __pgprot(pgprot_val(prot) |
                                cachemode2protval(_PAGE_CACHE_MODE_WC));
-       else
-               return pgprot_noncached(prot);
 }
 EXPORT_SYMBOL_GPL(pgprot_writecombine);