x86: not overmap more than the end of RAM in init_memory_mapping - 64bit

handle head and tail that are not aligned to big pages (2MB/1GB boundary).

with this patch, on system that support gbpages, change:

  last_map_addr: 1080000000 end: 1078000000

to:

  last_map_addr: 1078000000 end: 1078000000

Signed-off-by: Yinghai Lu <yhlu.kernel@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

diff --git a/arch/x86/mm/init_64.c b/arch/x86/mm/init_64.c
index f7d8031..51f69b3 100644 (file)
--- a/arch/x86/mm/init_64.c
+++ b/arch/x86/mm/init_64.c
@@ -462,18 +462,25 @@ phys_pud_update(pgd_t *pgd, unsigned long addr, unsigned long end,
 
 static void __init find_early_table_space(unsigned long end)
 {
-       unsigned long puds, tables, start;
+       unsigned long puds, pmds, ptes, tables, start;
 
        puds = (end + PUD_SIZE - 1) >> PUD_SHIFT;
        tables = round_up(puds * sizeof(pud_t), PAGE_SIZE);
-       if (!direct_gbpages) {
-               unsigned long pmds = (end + PMD_SIZE - 1) >> PMD_SHIFT;
-               tables += round_up(pmds * sizeof(pmd_t), PAGE_SIZE);
-       }
-       if (!cpu_has_pse) {
-               unsigned long ptes = (end + PAGE_SIZE - 1) >> PAGE_SHIFT;
-               tables += round_up(ptes * sizeof(pte_t), PAGE_SIZE);
-       }
+       if (direct_gbpages) {
+               unsigned long extra;
+               extra = end - ((end>>PUD_SHIFT) << PUD_SHIFT);
+               pmds = (extra + PMD_SIZE - 1) >> PMD_SHIFT;
+       } else
+               pmds = (end + PMD_SIZE - 1) >> PMD_SHIFT;
+       tables += round_up(pmds * sizeof(pmd_t), PAGE_SIZE);
+
+       if (cpu_has_pse) {
+               unsigned long extra;
+               extra = end - ((end>>PMD_SHIFT) << PMD_SHIFT);
+               ptes = (extra + PAGE_SIZE - 1) >> PAGE_SHIFT;
+       } else
+               ptes = (end + PAGE_SIZE - 1) >> PAGE_SHIFT;
+       tables += round_up(ptes * sizeof(pte_t), PAGE_SIZE);
 
        /*
         * RED-PEN putting page tables only on node 0 could
@@ -660,8 +667,9 @@ 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;
+       unsigned long last_map_addr = end;
        unsigned long page_size_mask = 0;
+       unsigned long start_pfn, end_pfn;
 
        printk(KERN_INFO "init_memory_mapping\n");
 
@@ -682,8 +690,53 @@ unsigned long __init_refok init_memory_mapping(unsigned long start,
        if (cpu_has_pse)
                page_size_mask |= 1 << PG_LEVEL_2M;
 
-       last_map_addr = kernel_physical_mapping_init(start, end,
-                                                        page_size_mask);
+       /* head if not big page aligment ?*/
+       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);
+
+       /* big page (2M) range*/
+       start_pfn = ((start + (PMD_SIZE - 1))>>PMD_SHIFT)
+                        << (PMD_SHIFT - PAGE_SHIFT);
+       end_pfn = ((start + (PUD_SIZE - 1))>>PUD_SHIFT)
+                        << (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));
+
+       /* 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)));
+
+       /* 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));
+       /* tail is not big page (2M) alignment */
+       start_pfn = end_pfn;
+       end_pfn = end>>PAGE_SHIFT;
+       if (start_pfn < end_pfn)
+               last_map_addr = kernel_physical_mapping_init(
+                                            start_pfn<<PAGE_SHIFT,
+                                            end_pfn<<PAGE_SHIFT, 0);
 
        if (!after_bootmem)
                mmu_cr4_features = read_cr4();