x86: have set_memory_array_{uc,wb} coalesce memtypes.

Actually, might as well simply reconstruct the memtype list at free time
I guess. How is this for a coalescing version of the array functions?

Compiles, boots and provides me with:

  root@7ixe4:~# wc -l /debug/x86/pat_memtype_list
  53 /debug/x86/pat_memtype_list

otherwise (down from 16384+).

Signed-off-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 32 insertions, 6 deletions

diff --git a/arch/x86/mm/pageattr.c b/arch/x86/mm/pageattr.c
index fed6ba2a8e7e..497108825da9 100644
--- a/arch/x86/mm/pageattr.c
+++ b/arch/x86/mm/pageattr.c
@@ -942,21 +942,38 @@ EXPORT_SYMBOL(set_memory_uc);
 
 int set_memory_array_uc(unsigned long *addr, int addrinarray)
 {
+        unsigned long start;
+        unsigned long end;
         int i;
         /*
          * for now UC MINUS. see comments in ioremap_nocache()
          */
         for (i = 0; i < addrinarray; i++) {
-                if (reserve_memtype(__pa(addr[i]), __pa(addr[i]) + PAGE_SIZE,
-                            _PAGE_CACHE_UC_MINUS, NULL))
+                start = __pa(addr[i]);
+                for (end = start + PAGE_SIZE; i < addrinarray - 1; end += PAGE_SIZE) {
+                        if (end != __pa(addr[i + 1]))
+                                break;
+                        i++;
+                }
+                if (reserve_memtype(start, end, _PAGE_CACHE_UC_MINUS, NULL))
                         goto out;
         }
 
         return change_page_attr_set(addr, addrinarray,
                                     __pgprot(_PAGE_CACHE_UC_MINUS), 1);
 out:
-        while (--i >= 0)
-                free_memtype(__pa(addr[i]), __pa(addr[i]) + PAGE_SIZE);
+        for (i = 0; i < addrinarray; i++) {
+                unsigned long tmp = __pa(addr[i]);
+
+                if (tmp == start)
+                        break;
+                for (end = start + PAGE_SIZE; i < addrinarray - 1; end += PAGE_SIZE) {
+                        if (end != __pa(addr[i + 1]))
+                                break;
+                        i++;
+                }
+                free_memtype(tmp, end);
+        }
         return -EINVAL;
 }
 EXPORT_SYMBOL(set_memory_array_uc);
@@ -997,9 +1014,18 @@ EXPORT_SYMBOL(set_memory_wb);
 int set_memory_array_wb(unsigned long *addr, int addrinarray)
 {
         int i;
-        for (i = 0; i < addrinarray; i++)
-                free_memtype(__pa(addr[i]), __pa(addr[i]) + PAGE_SIZE);
 
+        for (i = 0; i < addrinarray; i++) {
+                unsigned long start = __pa(addr[i]);
+                unsigned long end;
+
+                for (end = start + PAGE_SIZE; i < addrinarray - 1; end += PAGE_SIZE) {
+                        if (end != __pa(addr[i + 1]))
+                                break;
+                        i++;
+                }
+                free_memtype(start, end);
+        }
         return change_page_attr_clear(addr, addrinarray,
                                       __pgprot(_PAGE_CACHE_MASK), 1);
 }