x86: account overlapped mappings in max_pfn_mapped

When end_pfn is not aligned to 2MB (or 1GB) then the kernel might
map more memory than end_pfn. Account this in max_pfn_mapped.

Signed-off-by: Andi Kleen <ak@suse.de>
Cc: andreas.herrmann3@amd.com
Cc: mingo@elte.hu
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

4 files changed, 27 insertions, 14 deletions

diff --git a/arch/x86/kernel/setup_64.c b/arch/x86/kernel/setup_64.c
index 413b8fc31545..3d76dbd9f2c0 100644
--- a/arch/x86/kernel/setup_64.c
+++ b/arch/x86/kernel/setup_64.c
@@ -347,7 +347,7 @@ void __init setup_arch(char **cmdline_p)
 
         check_efer();
 
-        init_memory_mapping(0, (max_pfn_mapped << PAGE_SHIFT));
+        max_pfn_mapped = init_memory_mapping(0, (max_pfn_mapped << PAGE_SHIFT));
         if (efi_enabled)
                 efi_init();
 
diff --git a/arch/x86/mm/init_64.c b/arch/x86/mm/init_64.c
index ef9e9cfb1fc2..1076097dcab2 100644
--- a/arch/x86/mm/init_64.c
+++ b/arch/x86/mm/init_64.c
@@ -313,7 +313,7 @@ __meminit void early_iounmap(void *addr, unsigned long size)
         __flush_tlb_all();
 }
 
-static void __meminit
+static unsigned long __meminit
 phys_pmd_init(pmd_t *pmd_page, unsigned long address, unsigned long end)
 {
         int i = pmd_index(address);
@@ -335,21 +335,26 @@ phys_pmd_init(pmd_t *pmd_page, unsigned long address, unsigned long end)
                 set_pte((pte_t *)pmd,
                         pfn_pte(address >> PAGE_SHIFT, PAGE_KERNEL_LARGE));
         }
+        return address;
 }
 
-static void __meminit
+static unsigned long __meminit
 phys_pmd_update(pud_t *pud, unsigned long address, unsigned long end)
 {
         pmd_t *pmd = pmd_offset(pud, 0);
+        unsigned long last_map_addr;
+
         spin_lock(&init_mm.page_table_lock);
-        phys_pmd_init(pmd, address, end);
+        last_map_addr = phys_pmd_init(pmd, address, end);
         spin_unlock(&init_mm.page_table_lock);
         __flush_tlb_all();
+        return last_map_addr;
 }
 
-static void __meminit
+static unsigned long __meminit
 phys_pud_init(pud_t *pud_page, unsigned long addr, unsigned long end)
 {
+        unsigned long last_map_addr = end;
         int i = pud_index(addr);
 
         for (; i < PTRS_PER_PUD; i++, addr = (addr & PUD_MASK) + PUD_SIZE) {
@@ -368,13 +373,14 @@ phys_pud_init(pud_t *pud_page, unsigned long addr, unsigned long end)
 
                 if (pud_val(*pud)) {
                         if (!pud_large(*pud))
-                                phys_pmd_update(pud, addr, end);
+                                last_map_addr = phys_pmd_update(pud, addr, end);
                         continue;
                 }
 
                 if (direct_gbpages) {
                         set_pte((pte_t *)pud,
                                 pfn_pte(addr >> PAGE_SHIFT, PAGE_KERNEL_LARGE));
+                        last_map_addr = (addr & PUD_MASK) + PUD_SIZE;
                         continue;
                 }
 
@@ -382,12 +388,14 @@ phys_pud_init(pud_t *pud_page, unsigned long addr, unsigned long end)
 
                 spin_lock(&init_mm.page_table_lock);
                 set_pud(pud, __pud(pmd_phys | _KERNPG_TABLE));
-                phys_pmd_init(pmd, addr, end);
+                last_map_addr = phys_pmd_init(pmd, addr, end);
                 spin_unlock(&init_mm.page_table_lock);
 
                 unmap_low_page(pmd);
         }
         __flush_tlb_all();
+
+        return last_map_addr >> PAGE_SHIFT;
 }
 
 static void __init find_early_table_space(unsigned long end)
@@ -542,9 +550,9 @@ static void __init early_memtest(unsigned long start, unsigned long end)
  * This runs before bootmem is initialized and gets pages directly from
  * the physical memory. To access them they are temporarily mapped.
  */
-void __init_refok init_memory_mapping(unsigned long start, unsigned long end)
+unsigned long __init_refok init_memory_mapping(unsigned long start, unsigned long end)
 {
-        unsigned long next;
+        unsigned long next, last_map_addr = end;
         unsigned long start_phys = start, end_phys = end;
 
         printk(KERN_INFO "init_memory_mapping\n");
@@ -577,7 +585,7 @@ void __init_refok init_memory_mapping(unsigned long start, unsigned long end)
                 next = start + PGDIR_SIZE;
                 if (next > end)
                         next = end;
-                phys_pud_init(pud, __pa(start), __pa(next));
+                last_map_addr = phys_pud_init(pud, __pa(start), __pa(next));
                 if (!after_bootmem)
                         set_pgd(pgd_offset_k(start), mk_kernel_pgd(pud_phys));
                 unmap_low_page(pud);
@@ -593,6 +601,8 @@ void __init_refok init_memory_mapping(unsigned long start, unsigned long end)
 
         if (!after_bootmem)
                 early_memtest(start_phys, end_phys);
+
+        return last_map_addr;
 }
 
 #ifndef CONFIG_NUMA
@@ -632,11 +642,13 @@ int arch_add_memory(int nid, u64 start, u64 size)
 {
         struct pglist_data *pgdat = NODE_DATA(nid);
         struct zone *zone = pgdat->node_zones + ZONE_NORMAL;
-        unsigned long start_pfn = start >> PAGE_SHIFT;
+        unsigned long last_mapped_pfn, start_pfn = start >> PAGE_SHIFT;
         unsigned long nr_pages = size >> PAGE_SHIFT;
         int ret;
 
-        init_memory_mapping(start, start + size-1);
+        last_mapped_pfn = init_memory_mapping(start, start + size-1);
+        if (last_mapped_pfn > max_pfn_mapped)
+                max_pfn_mapped = last_mapped_pfn;
 
         ret = __add_pages(zone, start_pfn, nr_pages);
         WARN_ON(1);
diff --git a/include/asm-x86/page_64.h b/include/asm-x86/page_64.h
index 54d5db634858..6ea72859c491 100644
--- a/include/asm-x86/page_64.h
+++ b/include/asm-x86/page_64.h
@@ -80,6 +80,9 @@ typedef struct { pteval_t pte; } pte_t;
 
 #define vmemmap ((struct page *)VMEMMAP_START)
 
+extern unsigned long init_memory_mapping(unsigned long start,
+                                         unsigned long end);
+
 #endif  /* !__ASSEMBLY__ */
 
 #ifdef CONFIG_FLATMEM
diff --git a/include/asm-x86/proto.h b/include/asm-x86/proto.h
index 9da46af3b0e9..1e17bcce450e 100644
--- a/include/asm-x86/proto.h
+++ b/include/asm-x86/proto.h
@@ -7,8 +7,6 @@
 
 extern void early_idt_handler(void);
 
-extern void init_memory_mapping(unsigned long start, unsigned long end);
-
 extern void system_call(void);
 extern void syscall_init(void);