introduce two APIs for page attribute

Introduce two APIs for page attribute. flushing tlb/cache in every page
attribute is expensive. AGP gart usually will do a lot of operations to
change a page to uc, new APIs can reduce flush.

Signed-off-by: Shaohua Li <shaohua.li@intel.com>
Cc: airlied@linux.ie
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Arjan van de Ven <arjan@infradead.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

diff --git a/arch/x86/mm/pageattr.c b/arch/x86/mm/pageattr.c
index 65c6e46..2c5c18c 100644 (file)
--- a/arch/x86/mm/pageattr.c
+++ b/arch/x86/mm/pageattr.c
@@ -752,12 +752,12 @@ static inline int cache_attr(pgprot_t attr)
                (_PAGE_PAT | _PAGE_PAT_LARGE | _PAGE_PWT | _PAGE_PCD);
 }
 
-static int change_page_attr_set_clr(unsigned long addr, int numpages,
+static int do_change_page_attr_set_clr(unsigned long addr, int numpages,
                                    pgprot_t mask_set, pgprot_t mask_clr,
-                                   int force_split)
+                                   int force_split, int *tlb_flush)
 {
        struct cpa_data cpa;
-       int ret, cache, checkalias;
+       int ret, checkalias;
 
        /*
         * Check, if we are requested to change a not supported
@@ -792,9 +792,22 @@ static int change_page_attr_set_clr(unsigned long addr, int numpages,
        /*
         * Check whether we really changed something:
         */
-       if (!cpa.flushtlb)
-               goto out;
+       *tlb_flush = cpa.flushtlb;
+       cpa_fill_pool(NULL);
+
+       return ret;
+}
+
+static int change_page_attr_set_clr(unsigned long addr, int numpages,
+                                   pgprot_t mask_set, pgprot_t mask_clr,
+                                   int force_split)
+{
+       int cache, flush_cache = 0, ret;
 
+       ret = do_change_page_attr_set_clr(addr, numpages, mask_set, mask_clr,
+               force_split, &flush_cache);
+       if (!flush_cache)
+               goto out;
        /*
         * No need to flush, when we did not set any of the caching
         * attributes:
@@ -811,10 +824,7 @@ static int change_page_attr_set_clr(unsigned long addr, int numpages,
                cpa_flush_range(addr, numpages, cache);
        else
                cpa_flush_all(cache);
-
 out:
-       cpa_fill_pool(NULL);
-
        return ret;
 }
 
@@ -852,6 +862,30 @@ int set_memory_uc(unsigned long addr, int numpages)
 }
 EXPORT_SYMBOL(set_memory_uc);
 
+int set_memory_uc_noflush(unsigned long addr, int numpages)
+{
+       int flush;
+       /*
+        * for now UC MINUS. see comments in ioremap_nocache()
+        */
+       if (reserve_memtype(addr, addr + numpages * PAGE_SIZE,
+                           _PAGE_CACHE_UC_MINUS, NULL))
+               return -EINVAL;
+       /*
+        * for now UC MINUS. see comments in ioremap_nocache()
+        */
+       return do_change_page_attr_set_clr(addr, numpages,
+                                   __pgprot(_PAGE_CACHE_UC_MINUS),
+                                       __pgprot(0), 0, &flush);
+}
+EXPORT_SYMBOL(set_memory_uc_noflush);
+
+void set_memory_flush_all(void)
+{
+       cpa_flush_all(1);
+}
+EXPORT_SYMBOL(set_memory_flush_all);
+
 int _set_memory_wc(unsigned long addr, int numpages)
 {
        return change_page_attr_set(addr, numpages,
@@ -926,6 +960,14 @@ int set_pages_uc(struct page *page, int numpages)
 }
 EXPORT_SYMBOL(set_pages_uc);
 
+int set_pages_uc_noflush(struct page *page, int numpages)
+{
+       unsigned long addr = (unsigned long)page_address(page);
+
+       return set_memory_uc_noflush(addr, numpages);
+}
+EXPORT_SYMBOL(set_pages_uc_noflush);
+
 int set_pages_wb(struct page *page, int numpages)
 {
        unsigned long addr = (unsigned long)page_address(page);

diff --git a/include/asm-x86/cacheflush.h b/include/asm-x86/cacheflush.h
index f4c0ab5..57bac7b 100644 (file)
--- a/include/asm-x86/cacheflush.h
+++ b/include/asm-x86/cacheflush.h
@@ -57,6 +57,8 @@ int _set_memory_uc(unsigned long addr, int numpages);
 int _set_memory_wc(unsigned long addr, int numpages);
 int _set_memory_wb(unsigned long addr, int numpages);
 int set_memory_uc(unsigned long addr, int numpages);
+int set_memory_uc_noflush(unsigned long addr, int numpages);
+void set_memory_flush_all(void);
 int set_memory_wc(unsigned long addr, int numpages);
 int set_memory_wb(unsigned long addr, int numpages);
 int set_memory_x(unsigned long addr, int numpages);
@@ -87,6 +89,7 @@ int set_memory_4k(unsigned long addr, int numpages);
  */
 
 int set_pages_uc(struct page *page, int numpages);
+int set_pages_uc_noflush(struct page *page, int numpages);
 int set_pages_wb(struct page *page, int numpages);
 int set_pages_x(struct page *page, int numpages);
 int set_pages_nx(struct page *page, int numpages);