x86: overmapped fix when 4K pages on tail, 64-bit

fix phys_pmd_init to make sure not to return bigger value than end.

also print out range split:1G/2M/4K in init_memory_mapping().

Signed-off-by: Yinghai Lu <yhlu.kernel@gmail.com>
Cc: Suresh Siddha <suresh.b.siddha@intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 72 insertions, 34 deletions

diff --git a/arch/x86/mm/init_64.c b/arch/x86/mm/init_64.c
index 51f69b39b752..48548ef7ddf8 100644
--- a/arch/x86/mm/init_64.c
+++ b/arch/x86/mm/init_64.c
@@ -302,11 +302,13 @@ static __meminit void unmap_low_page(void *adr)
         early_iounmap(adr, PAGE_SIZE);
 }
 
-static void __meminit
+static unsigned long __meminit
 phys_pte_init(pte_t *pte_page, unsigned long addr, unsigned long end)
 {
         unsigned pages = 0;
+        unsigned long last_map_addr = end;
         int i;
+
         pte_t *pte = pte_page + pte_index(addr);
 
         for(i = pte_index(addr); i < PTRS_PER_PTE; i++, addr += PAGE_SIZE, pte++) {
@@ -326,17 +328,20 @@ phys_pte_init(pte_t *pte_page, unsigned long addr, unsigned long end)
                         printk("   pte=%p addr=%lx pte=%016lx\n",
                                pte, addr, pfn_pte(addr >> PAGE_SHIFT, PAGE_KERNEL).pte);
                 set_pte(pte, pfn_pte(addr >> PAGE_SHIFT, PAGE_KERNEL));
+                last_map_addr = (addr & PAGE_MASK) + PAGE_SIZE;
                 pages++;
         }
         update_page_count(PG_LEVEL_4K, pages);
+
+        return last_map_addr;
 }
 
-static void __meminit
+static unsigned long __meminit
 phys_pte_update(pmd_t *pmd, unsigned long address, unsigned long end)
 {
         pte_t *pte = (pte_t *)pmd_page_vaddr(*pmd);
 
-        phys_pte_init(pte, address, end);
+        return phys_pte_init(pte, address, end);
 }
 
 static unsigned long __meminit
@@ -344,6 +349,7 @@ phys_pmd_init(pmd_t *pmd_page, unsigned long address, unsigned long end,
                          unsigned long page_size_mask)
 {
         unsigned long pages = 0;
+        unsigned long last_map_addr = end;
 
         int i = pmd_index(address);
 
@@ -362,7 +368,8 @@ phys_pmd_init(pmd_t *pmd_page, unsigned long address, unsigned long end,
 
                 if (pmd_val(*pmd)) {
                         if (!pmd_large(*pmd))
-                                phys_pte_update(pmd, address, end);
+                                last_map_addr = phys_pte_update(pmd, address,
+                                                                 end);
                         continue;
                 }
 
@@ -370,17 +377,18 @@ phys_pmd_init(pmd_t *pmd_page, unsigned long address, unsigned long end,
                         pages++;
                         set_pte((pte_t *)pmd,
                                 pfn_pte(address >> PAGE_SHIFT, PAGE_KERNEL_LARGE));
+                        last_map_addr = (address & PMD_MASK) + PMD_SIZE;
                         continue;
                 }
 
                 pte = alloc_low_page(&pte_phys);
-                phys_pte_init(pte, address, end);
+                last_map_addr = phys_pte_init(pte, address, end);
                 unmap_low_page(pte);
 
                 pmd_populate_kernel(&init_mm, pmd, __va(pte_phys));
         }
         update_page_count(PG_LEVEL_2M, pages);
-        return address;
+        return last_map_addr;
 }
 
 static unsigned long __meminit
@@ -659,6 +667,32 @@ static unsigned long __init kernel_physical_mapping_init(unsigned long start,
 
         return last_map_addr;
 }
+
+struct map_range {
+        unsigned long start;
+        unsigned long end;
+        unsigned page_size_mask;
+};
+
+#define NR_RANGE_MR 5
+
+static int save_mr(struct map_range *mr, int nr_range,
+                   unsigned long start_pfn, unsigned long end_pfn,
+                   unsigned long page_size_mask)
+{
+
+        if (start_pfn < end_pfn) {
+                if (nr_range >= NR_RANGE_MR)
+                        panic("run out of range for init_memory_mapping\n");
+                mr[nr_range].start = start_pfn<<PAGE_SHIFT;
+                mr[nr_range].end   = end_pfn<<PAGE_SHIFT;
+                mr[nr_range].page_size_mask = page_size_mask;
+                nr_range++;
+        }
+
+        return nr_range;
+}
+
 /*
  * Setup the direct mapping of the physical memory at PAGE_OFFSET.
  * This runs before bootmem is initialized and gets pages directly from
@@ -667,10 +701,13 @@ static unsigned long __init kernel_physical_mapping_init(unsigned long start,
 unsigned long __init_refok init_memory_mapping(unsigned long start,
                                                unsigned long end)
 {
-        unsigned long last_map_addr = end;
+        unsigned long last_map_addr = 0;
         unsigned long page_size_mask = 0;
         unsigned long start_pfn, end_pfn;
 
+        struct map_range mr[NR_RANGE_MR];
+        int nr_range, i;
+
         printk(KERN_INFO "init_memory_mapping\n");
 
         /*
@@ -680,24 +717,22 @@ unsigned long __init_refok init_memory_mapping(unsigned long start,
          * memory mapped. Unfortunately this is done currently before the
          * nodes are discovered.
          */
-        if (!after_bootmem) {
+        if (!after_bootmem)
                 init_gbpages();
-                find_early_table_space(end);
-        }
 
         if (direct_gbpages)
                 page_size_mask |= 1 << PG_LEVEL_1G;
         if (cpu_has_pse)
                 page_size_mask |= 1 << PG_LEVEL_2M;
 
-        /* head if not big page aligment ?*/
+        memset(mr, 0, sizeof(mr));
+        nr_range = 0;
+
+        /* head if not big page alignment ?*/
         start_pfn = start >> PAGE_SHIFT;
         end_pfn = ((start + (PMD_SIZE - 1)) >> PMD_SHIFT)
                         << (PMD_SHIFT - PAGE_SHIFT);
-        if (start_pfn < end_pfn)
-                last_map_addr = kernel_physical_mapping_init(
-                                        start_pfn<<PAGE_SHIFT,
-                                        end_pfn<<PAGE_SHIFT, 0);
+        nr_range = save_mr(mr, nr_range, start_pfn, end_pfn, 0);
 
         /* big page (2M) range*/
         start_pfn = ((start + (PMD_SIZE - 1))>>PMD_SHIFT)
@@ -706,37 +741,40 @@ unsigned long __init_refok init_memory_mapping(unsigned long start,
                          << (PUD_SHIFT - PAGE_SHIFT);
         if (end_pfn > ((end>>PUD_SHIFT)<<(PUD_SHIFT - PAGE_SHIFT)))
                 end_pfn = ((end>>PUD_SHIFT)<<(PUD_SHIFT - PAGE_SHIFT));
-        if (start_pfn < end_pfn)
-                last_map_addr = kernel_physical_mapping_init(
-                                             start_pfn<<PAGE_SHIFT,
-                                             end_pfn<<PAGE_SHIFT,
-                                             page_size_mask & (1<<PG_LEVEL_2M));
+        nr_range = save_mr(mr, nr_range, start_pfn, end_pfn,
+                        page_size_mask & (1<<PG_LEVEL_2M));
 
         /* big page (1G) range */
         start_pfn = end_pfn;
         end_pfn = (end>>PUD_SHIFT) << (PUD_SHIFT - PAGE_SHIFT);
-        if (start_pfn < end_pfn)
-                last_map_addr = kernel_physical_mapping_init(
-                                             start_pfn<<PAGE_SHIFT,
-                                             end_pfn<<PAGE_SHIFT,
-                                             page_size_mask & ((1<<PG_LEVEL_2M)
-                                                         | (1<<PG_LEVEL_1G)));
+        nr_range = save_mr(mr, nr_range, start_pfn, end_pfn,
+                                page_size_mask &
+                                 ((1<<PG_LEVEL_2M)|(1<<PG_LEVEL_1G)));
 
         /* tail is not big page (1G) alignment */
         start_pfn = end_pfn;
         end_pfn = (end>>PMD_SHIFT) << (PMD_SHIFT - PAGE_SHIFT);
-        if (start_pfn < end_pfn)
-                last_map_addr = kernel_physical_mapping_init(
-                                             start_pfn<<PAGE_SHIFT,
-                                             end_pfn<<PAGE_SHIFT,
-                                             page_size_mask & (1<<PG_LEVEL_2M));
+        nr_range = save_mr(mr, nr_range, start_pfn, end_pfn,
+                        page_size_mask & (1<<PG_LEVEL_2M));
+
         /* tail is not big page (2M) alignment */
         start_pfn = end_pfn;
         end_pfn = end>>PAGE_SHIFT;
-        if (start_pfn < end_pfn)
+        nr_range = save_mr(mr, nr_range, start_pfn, end_pfn, 0);
+
+        for (i = 0; i < nr_range; i++)
+                printk(KERN_DEBUG " %010lx - %010lx page %s\n",
+                                mr[i].start, mr[i].end,
+                        (mr[i].page_size_mask & (1<<PG_LEVEL_1G))?"1G":(
+                         (mr[i].page_size_mask & (1<<PG_LEVEL_2M))?"2M":"4k"));
+
+        if (!after_bootmem)
+                find_early_table_space(end);
+
+        for (i = 0; i < nr_range; i++)
                 last_map_addr = kernel_physical_mapping_init(
-                                             start_pfn<<PAGE_SHIFT,
-                                             end_pfn<<PAGE_SHIFT, 0);
+                                        mr[i].start, mr[i].end,
+                                        mr[i].page_size_mask);
 
         if (!after_bootmem)
                 mmu_cr4_features = read_cr4();