[PATCH UPDATED 2/4] x86: reorganize cpa_process_alias()

Tejun Heo
2009-05-14T16:20:29Z

Reorganize cpa_process_alias() so that new alias condition can be
added easily.

Jan Beulich spotted problem in the original cleanup thread which
incorrectly assumed the two existing conditions were mutially
exclusive.

[ Impact: code reorganization ]

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Jan Beulich <JBeulich@novell.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Ingo Molnar <mingo@elte.hu>
---
arch/x86/mm/pageattr.c | 44 ++++++++++++++++++++------------------------
1 files changed, 20 insertions(+), 24 deletions(-)

diff --git a/arch/x86/mm/pageattr.c b/arch/x86/mm/pageattr.c
index 797f9f1..8bc64b0 100644
--- a/arch/x86/mm/pageattr.c
+++ b/arch/x86/mm/pageattr.c
@@ -686,8 +686,8 @@ static int __change_page_attr_set_clr(struct cpa_data *cpa, int checkalias);
static int cpa_process_alias(struct cpa_data *cpa)
{
struct cpa_data alias_cpa;
- int ret = 0;
unsigned long temp_cpa_vaddr, vaddr;
+ int ret;

if (cpa->pfn >= max_pfn_mapped)
return 0;
@@ -715,38 +715,34 @@ static int cpa_process_alias(struct cpa_data *cpa)
alias_cpa.vaddr = &temp_cpa_vaddr;
alias_cpa.flags &= ~(CPA_PAGES_ARRAY | CPA_ARRAY);

-
ret = __change_page_attr_set_clr(&alias_cpa, 0);
+ if (ret)
+ return ret;
}

#ifdef CONFIG_X86_64
- if (ret)
- return ret;
/*
- * No need to redo, when the primary call touched the high
- * mapping already:
- */
- if (within(vaddr, (unsigned long) _text, _brk_end))
- return 0;
-
- /*
- * If the physical address is inside the kernel map, we need
+ * If the primary call didn't touch the high mapping already
+ * and the physical address is inside the kernel map, we need
* to touch the high mapped kernel as well:
*/
- if (!within(cpa->pfn, highmap_start_pfn(), highmap_end_pfn()))
- return 0;
-
- alias_cpa = *cpa;
- temp_cpa_vaddr = (cpa->pfn << PAGE_SHIFT) + __START_KERNEL_map - phys_base;
- alias_cpa.vaddr = &temp_cpa_vaddr;
- alias_cpa.flags &= ~(CPA_PAGES_ARRAY | CPA_ARRAY);
+ if (!within(vaddr, (unsigned long)_text, _brk_end) &&
+ within(cpa->pfn, highmap_start_pfn(), highmap_end_pfn())) {
+ alias_cpa = *cpa;
+ temp_cpa_vaddr = (cpa->pfn << PAGE_SHIFT) +
+ __START_KERNEL_map - phys_base;
+ alias_cpa.vaddr = &temp_cpa_vaddr;
+ alias_cpa.flags &= ~(CPA_PAGES_ARRAY | CPA_ARRAY);

- /*
- * The high mapping range is imprecise, so ignore the return value.
- */
- __change_page_attr_set_clr(&alias_cpa, 0);
+ /*
+ * The high mapping range is imprecise, so ignore the
+ * return value.
+ */
+ __change_page_attr_set_clr(&alias_cpa, 0);
+ }
#endif
- return ret;
+
+ return 0;
}

static int __change_page_attr_set_clr(struct cpa_data *cpa, int checkalias)
--
1.6.0.2