From b6ff32d9aaeeeecf98f9a852d715569183585312 Mon Sep 17 00:00:00 2001
From: Suresh Siddha <suresh.b.siddha@intel.com>
Date: Thu, 9 Apr 2009 14:26:51 -0700
Subject: [PATCH] x86, PAT: Consolidate code in pat_x_mtrr_type() and
reserve_memtype()
Fix pat_x_mtrr_type() to use UC_MINUS when the mtrr type return UC. This
is to be consistent with ioremap() and ioremap_nocache() which uses
UC_MINUS.
Consolidate the code such that reserve_memtype() also uses
pat_x_mtrr_type() when the caller doesn't specify any special attribute
(non WB attribute).
Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
LKML-Reference: <20090409212708.939936000@intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
---
arch/x86/mm/ioremap.c | 3 ++-
arch/x86/mm/pat.c | 35 +++++++++++++----------------------
2 files changed, 15 insertions(+), 23 deletions(-)
diff --git a/arch/x86/mm/ioremap.c b/arch/x86/mm/ioremap.c
index 329387eca12ad..d4c4b2c4dbbe8 100644
--- a/arch/x86/mm/ioremap.c
+++ b/arch/x86/mm/ioremap.c
@@ -375,7 +375,8 @@ static void __iomem *ioremap_default(resource_size_t phys_addr,
* - UC_MINUS for non-WB-able memory with no other conflicting mappings
* - Inherit from confliting mappings otherwise
*/
- err = reserve_memtype(phys_addr, phys_addr + size, -1, &flags);
+ err = reserve_memtype(phys_addr, phys_addr + size,
+ _PAGE_CACHE_WB, &flags);
if (err < 0)
return NULL;
diff --git a/arch/x86/mm/pat.c b/arch/x86/mm/pat.c
index 640339ee4fb2a..8d3de95805088 100644
--- a/arch/x86/mm/pat.c
+++ b/arch/x86/mm/pat.c
@@ -182,10 +182,10 @@ static unsigned long pat_x_mtrr_type(u64 start, u64 end, unsigned long req_type)
u8 mtrr_type;
mtrr_type = mtrr_type_lookup(start, end);
- if (mtrr_type == MTRR_TYPE_UNCACHABLE)
- return _PAGE_CACHE_UC;
- if (mtrr_type == MTRR_TYPE_WRCOMB)
- return _PAGE_CACHE_WC;
+ if (mtrr_type != MTRR_TYPE_WRBACK)
+ return _PAGE_CACHE_UC_MINUS;
+
+ return _PAGE_CACHE_WB;
}
return req_type;
@@ -352,23 +352,13 @@ int reserve_memtype(u64 start, u64 end, unsigned long req_type,
return 0;
}
- if (req_type == -1) {
- /*
- * Call mtrr_lookup to get the type hint. This is an
- * optimization for /dev/mem mmap'ers into WB memory (BIOS
- * tools and ACPI tools). Use WB request for WB memory and use
- * UC_MINUS otherwise.
- */
- u8 mtrr_type = mtrr_type_lookup(start, end);
-
- if (mtrr_type == MTRR_TYPE_WRBACK)
- actual_type = _PAGE_CACHE_WB;
- else
- actual_type = _PAGE_CACHE_UC_MINUS;
- } else {
- actual_type = pat_x_mtrr_type(start, end,
- req_type & _PAGE_CACHE_MASK);
- }
+ /*
+ * Call mtrr_lookup to get the type hint. This is an
+ * optimization for /dev/mem mmap'ers into WB memory (BIOS
+ * tools and ACPI tools). Use WB request for WB memory and use
+ * UC_MINUS otherwise.
+ */
+ actual_type = pat_x_mtrr_type(start, end, req_type & _PAGE_CACHE_MASK);
if (new_type)
*new_type = actual_type;
@@ -587,7 +577,8 @@ int phys_mem_access_prot_allowed(struct file *file, unsigned long pfn,
if (flags != -1) {
retval = reserve_memtype(offset, offset + size, flags, NULL);
} else {
- retval = reserve_memtype(offset, offset + size, -1, &flags);
+ retval = reserve_memtype(offset, offset + size,
+ _PAGE_CACHE_WB, &flags);
}
if (retval < 0)
--
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