1 files changed, 59 insertions, 4 deletions

diff --git a/arch/x86/mm/pageattr.c b/arch/x86/mm/pageattr.c
index 60bcb5b6a37e..47f4e2e4a096 100644
--- a/arch/x86/mm/pageattr.c
+++ b/arch/x86/mm/pageattr.c
@@ -34,6 +34,41 @@ struct cpa_data {
         unsigned        force_split : 1;
 };
 
+#ifdef CONFIG_PROC_FS
+static unsigned long direct_pages_count[PG_LEVEL_NUM];
+
+void update_page_count(int level, unsigned long pages)
+{
+        unsigned long flags;
+
+        /* Protect against CPA */
+        spin_lock_irqsave(&pgd_lock, flags);
+        direct_pages_count[level] += pages;
+        spin_unlock_irqrestore(&pgd_lock, flags);
+}
+
+static void split_page_count(int level)
+{
+        direct_pages_count[level]--;
+        direct_pages_count[level - 1] += PTRS_PER_PTE;
+}
+
+int arch_report_meminfo(char *page)
+{
+        int n = sprintf(page, "DirectMap4k:  %8lu\n"
+                        "DirectMap2M:  %8lu\n",
+                        direct_pages_count[PG_LEVEL_4K],
+                        direct_pages_count[PG_LEVEL_2M]);
+#ifdef CONFIG_X86_64
+        n += sprintf(page + n, "DirectMap1G:  %8lu\n",
+                     direct_pages_count[PG_LEVEL_1G]);
+#endif
+        return n;
+}
+#else
+static inline void split_page_count(int level) { }
+#endif
+
 #ifdef CONFIG_X86_64
 
 static inline unsigned long highmap_start_pfn(void)
@@ -227,6 +262,7 @@ pte_t *lookup_address(unsigned long address, unsigned int *level)
 
         return pte_offset_kernel(pmd, address);
 }
+EXPORT_SYMBOL_GPL(lookup_address);
 
 /*
  * Set the new pmd in all the pgds we know about:
@@ -500,6 +536,16 @@ static int split_large_page(pte_t *kpte, unsigned long address)
         for (i = 0; i < PTRS_PER_PTE; i++, pfn += pfninc)
                 set_pte(&pbase[i], pfn_pte(pfn, ref_prot));
 
+        if (address >= (unsigned long)__va(0) &&
+                address < (unsigned long)__va(max_low_pfn_mapped << PAGE_SHIFT))
+                split_page_count(level);
+
+#ifdef CONFIG_X86_64
+        if (address >= (unsigned long)__va(1UL<<32) &&
+                address < (unsigned long)__va(max_pfn_mapped << PAGE_SHIFT))
+                split_page_count(level);
+#endif
+
         /*
          * Install the new, split up pagetable. Important details here:
          *
@@ -613,15 +659,24 @@ static int cpa_process_alias(struct cpa_data *cpa)
         struct cpa_data alias_cpa;
         int ret = 0;
 
-        if (cpa->pfn > max_pfn_mapped)
+        if (cpa->pfn >= max_pfn_mapped)
                 return 0;
 
+#ifdef CONFIG_X86_64
+        if (cpa->pfn >= max_low_pfn_mapped && cpa->pfn < (1UL<<(32-PAGE_SHIFT)))
+                return 0;
+#endif
         /*
          * No need to redo, when the primary call touched the direct
          * mapping already:
          */
-        if (!within(cpa->vaddr, PAGE_OFFSET,
-                    PAGE_OFFSET + (max_pfn_mapped << PAGE_SHIFT))) {
+        if (!(within(cpa->vaddr, PAGE_OFFSET,
+                    PAGE_OFFSET + (max_low_pfn_mapped << PAGE_SHIFT))
+#ifdef CONFIG_X86_64
+                || within(cpa->vaddr, PAGE_OFFSET + (1UL<<32),
+                    PAGE_OFFSET + (max_pfn_mapped << PAGE_SHIFT))
+#endif
+        )) {
 
                 alias_cpa = *cpa;
                 alias_cpa.vaddr = (unsigned long) __va(cpa->pfn << PAGE_SHIFT);
@@ -805,7 +860,7 @@ int _set_memory_wc(unsigned long addr, int numpages)
 
 int set_memory_wc(unsigned long addr, int numpages)
 {
-        if (!pat_wc_enabled)
+        if (!pat_enabled)
                 return set_memory_uc(addr, numpages);
 
         if (reserve_memtype(addr, addr + numpages * PAGE_SIZE,