x86: reorganize cpa_process_alias()

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>

diff --git a/arch/x86/mm/pageattr.c b/arch/x86/mm/pageattr.c
index 3cfe9ce..2ab058b 100644 (file)
--- a/arch/x86/mm/pageattr.c
+++ b/arch/x86/mm/pageattr.c
@@ -681,8 +681,9 @@ 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;
+       unsigned long laddr = (unsigned long)__va(cpa->pfn << PAGE_SHIFT);
+       unsigned long vaddr;
+       int ret;
 
        if (cpa->pfn >= max_pfn_mapped)
                return 0;
@@ -706,42 +707,37 @@ static int cpa_process_alias(struct cpa_data *cpa)
                    PAGE_OFFSET + (max_pfn_mapped << PAGE_SHIFT)))) {
 
                alias_cpa = *cpa;
-               temp_cpa_vaddr = (unsigned long) __va(cpa->pfn << PAGE_SHIFT);
-               alias_cpa.vaddr = &temp_cpa_vaddr;
+               alias_cpa.vaddr = &laddr;
                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())) {
+               unsigned long temp_cpa_vaddr = (cpa->pfn << PAGE_SHIFT) +
+                                              __START_KERNEL_map - phys_base;
+               alias_cpa = *cpa;
+               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)