lkml.org 
[lkml]   [2009]   [Apr]   [9]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
Date
From
Subject[patch 5/6] x86, PAT: Consolidate code in pat_x_mtrr_type() and reserve_memtype()
From: Suresh Siddha <suresh.b.siddha@intel.com>
Subject: [patch 5/6] 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>
---
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 329387e..d4c4b2c 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 95d3b1a..3c8624c 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)
--
1.6.0.6
--



\
 
 \ /
  Last update: 2009-04-10 00:15    [W:0.102 / U:0.324 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site