]> nv-tegra.nvidia Code Review - linux-2.6.git/blobdiff - arch/x86/mm/init.c
x86: Make sure free_init_pages() frees pages on page boundary
[linux-2.6.git] / arch / x86 / mm / init.c
index ce6a722587d8fa6cfd8343c3931866ce93eda13b..452ee5b8f30909fae2da150dcbd3cf4eaa67fa08 100644 (file)
+#include <linux/initrd.h>
+#include <linux/ioport.h>
 #include <linux/swap.h>
+
 #include <asm/cacheflush.h>
+#include <asm/e820.h>
+#include <asm/init.h>
 #include <asm/page.h>
+#include <asm/page_types.h>
 #include <asm/sections.h>
+#include <asm/setup.h>
 #include <asm/system.h>
+#include <asm/tlbflush.h>
+#include <asm/tlb.h>
+#include <asm/proto.h>
+
+DEFINE_PER_CPU(struct mmu_gather, mmu_gathers);
+
+unsigned long __initdata e820_table_start;
+unsigned long __meminitdata e820_table_end;
+unsigned long __meminitdata e820_table_top;
+
+int after_bootmem;
+
+int direct_gbpages
+#ifdef CONFIG_DIRECT_GBPAGES
+                               = 1
+#endif
+;
+
+static void __init find_early_table_space(unsigned long end, int use_pse,
+                                         int use_gbpages)
+{
+       unsigned long puds, pmds, ptes, tables, start;
+
+       puds = (end + PUD_SIZE - 1) >> PUD_SHIFT;
+       tables = roundup(puds * sizeof(pud_t), PAGE_SIZE);
+
+       if (use_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 += roundup(pmds * sizeof(pmd_t), PAGE_SIZE);
+
+       if (use_pse) {
+               unsigned long extra;
+
+               extra = end - ((end>>PMD_SHIFT) << PMD_SHIFT);
+#ifdef CONFIG_X86_32
+               extra += PMD_SIZE;
+#endif
+               ptes = (extra + PAGE_SIZE - 1) >> PAGE_SHIFT;
+       } else
+               ptes = (end + PAGE_SIZE - 1) >> PAGE_SHIFT;
+
+       tables += roundup(ptes * sizeof(pte_t), PAGE_SIZE);
+
+#ifdef CONFIG_X86_32
+       /* for fixmap */
+       tables += roundup(__end_of_fixed_addresses * sizeof(pte_t), PAGE_SIZE);
+#endif
+
+       /*
+        * RED-PEN putting page tables only on node 0 could
+        * cause a hotspot and fill up ZONE_DMA. The page tables
+        * need roughly 0.5KB per GB.
+        */
+#ifdef CONFIG_X86_32
+       start = 0x7000;
+#else
+       start = 0x8000;
+#endif
+       e820_table_start = find_e820_area(start, max_pfn_mapped<<PAGE_SHIFT,
+                                       tables, PAGE_SIZE);
+       if (e820_table_start == -1UL)
+               panic("Cannot find space for the kernel page tables");
+
+       e820_table_start >>= PAGE_SHIFT;
+       e820_table_end = e820_table_start;
+       e820_table_top = e820_table_start + (tables >> PAGE_SHIFT);
+
+       printk(KERN_DEBUG "kernel direct mapping tables up to %lx @ %lx-%lx\n",
+               end, e820_table_start << PAGE_SHIFT, e820_table_top << PAGE_SHIFT);
+}
+
+struct map_range {
+       unsigned long start;
+       unsigned long end;
+       unsigned page_size_mask;
+};
+
+#ifdef CONFIG_X86_32
+#define NR_RANGE_MR 3
+#else /* CONFIG_X86_64 */
+#define NR_RANGE_MR 5
+#endif
+
+static int __meminit 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
+ * the physical memory. To access them they are temporarily mapped.
+ */
+unsigned long __init_refok init_memory_mapping(unsigned long start,
+                                              unsigned long end)
+{
+       unsigned long page_size_mask = 0;
+       unsigned long start_pfn, end_pfn;
+       unsigned long ret = 0;
+       unsigned long pos;
+
+       struct map_range mr[NR_RANGE_MR];
+       int nr_range, i;
+       int use_pse, use_gbpages;
+
+       printk(KERN_INFO "init_memory_mapping: %016lx-%016lx\n", start, end);
+
+#if defined(CONFIG_DEBUG_PAGEALLOC) || defined(CONFIG_KMEMCHECK)
+       /*
+        * For CONFIG_DEBUG_PAGEALLOC, identity mapping will use small pages.
+        * This will simplify cpa(), which otherwise needs to support splitting
+        * large pages into small in interrupt context, etc.
+        */
+       use_pse = use_gbpages = 0;
+#else
+       use_pse = cpu_has_pse;
+       use_gbpages = direct_gbpages;
+#endif
+
+       /* Enable PSE if available */
+       if (cpu_has_pse)
+               set_in_cr4(X86_CR4_PSE);
+
+       /* Enable PGE if available */
+       if (cpu_has_pge) {
+               set_in_cr4(X86_CR4_PGE);
+               __supported_pte_mask |= _PAGE_GLOBAL;
+       }
+
+       if (use_gbpages)
+               page_size_mask |= 1 << PG_LEVEL_1G;
+       if (use_pse)
+               page_size_mask |= 1 << PG_LEVEL_2M;
+
+       memset(mr, 0, sizeof(mr));
+       nr_range = 0;
+
+       /* head if not big page alignment ? */
+       start_pfn = start >> PAGE_SHIFT;
+       pos = start_pfn << PAGE_SHIFT;
+#ifdef CONFIG_X86_32
+       /*
+        * Don't use a large page for the first 2/4MB of memory
+        * because there are often fixed size MTRRs in there
+        * and overlapping MTRRs into large pages can cause
+        * slowdowns.
+        */
+       if (pos == 0)
+               end_pfn = 1<<(PMD_SHIFT - PAGE_SHIFT);
+       else
+               end_pfn = ((pos + (PMD_SIZE - 1))>>PMD_SHIFT)
+                                << (PMD_SHIFT - PAGE_SHIFT);
+#else /* CONFIG_X86_64 */
+       end_pfn = ((pos + (PMD_SIZE - 1)) >> PMD_SHIFT)
+                       << (PMD_SHIFT - PAGE_SHIFT);
+#endif
+       if (end_pfn > (end >> PAGE_SHIFT))
+               end_pfn = end >> PAGE_SHIFT;
+       if (start_pfn < end_pfn) {
+               nr_range = save_mr(mr, nr_range, start_pfn, end_pfn, 0);
+               pos = end_pfn << PAGE_SHIFT;
+       }
+
+       /* big page (2M) range */
+       start_pfn = ((pos + (PMD_SIZE - 1))>>PMD_SHIFT)
+                        << (PMD_SHIFT - PAGE_SHIFT);
+#ifdef CONFIG_X86_32
+       end_pfn = (end>>PMD_SHIFT) << (PMD_SHIFT - PAGE_SHIFT);
+#else /* CONFIG_X86_64 */
+       end_pfn = ((pos + (PUD_SIZE - 1))>>PUD_SHIFT)
+                        << (PUD_SHIFT - PAGE_SHIFT);
+       if (end_pfn > ((end>>PMD_SHIFT)<<(PMD_SHIFT - PAGE_SHIFT)))
+               end_pfn = ((end>>PMD_SHIFT)<<(PMD_SHIFT - PAGE_SHIFT));
+#endif
+
+       if (start_pfn < end_pfn) {
+               nr_range = save_mr(mr, nr_range, start_pfn, end_pfn,
+                               page_size_mask & (1<<PG_LEVEL_2M));
+               pos = end_pfn << PAGE_SHIFT;
+       }
+
+#ifdef CONFIG_X86_64
+       /* big page (1G) range */
+       start_pfn = ((pos + (PUD_SIZE - 1))>>PUD_SHIFT)
+                        << (PUD_SHIFT - PAGE_SHIFT);
+       end_pfn = (end >> PUD_SHIFT) << (PUD_SHIFT - PAGE_SHIFT);
+       if (start_pfn < end_pfn) {
+               nr_range = save_mr(mr, nr_range, start_pfn, end_pfn,
+                               page_size_mask &
+                                ((1<<PG_LEVEL_2M)|(1<<PG_LEVEL_1G)));
+               pos = end_pfn << PAGE_SHIFT;
+       }
+
+       /* tail is not big page (1G) alignment */
+       start_pfn = ((pos + (PMD_SIZE - 1))>>PMD_SHIFT)
+                        << (PMD_SHIFT - PAGE_SHIFT);
+       end_pfn = (end >> PMD_SHIFT) << (PMD_SHIFT - PAGE_SHIFT);
+       if (start_pfn < end_pfn) {
+               nr_range = save_mr(mr, nr_range, start_pfn, end_pfn,
+                               page_size_mask & (1<<PG_LEVEL_2M));
+               pos = end_pfn << PAGE_SHIFT;
+       }
+#endif
+
+       /* tail is not big page (2M) alignment */
+       start_pfn = pos>>PAGE_SHIFT;
+       end_pfn = end>>PAGE_SHIFT;
+       nr_range = save_mr(mr, nr_range, start_pfn, end_pfn, 0);
+
+       /* try to merge same page size and continuous */
+       for (i = 0; nr_range > 1 && i < nr_range - 1; i++) {
+               unsigned long old_start;
+               if (mr[i].end != mr[i+1].start ||
+                   mr[i].page_size_mask != mr[i+1].page_size_mask)
+                       continue;
+               /* move it */
+               old_start = mr[i].start;
+               memmove(&mr[i], &mr[i+1],
+                       (nr_range - 1 - i) * sizeof(struct map_range));
+               mr[i--].start = old_start;
+               nr_range--;
+       }
+
+       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"));
+
+       /*
+        * Find space for the kernel direct mapping tables.
+        *
+        * Later we should allocate these tables in the local node of the
+        * memory mapped. Unfortunately this is done currently before the
+        * nodes are discovered.
+        */
+       if (!after_bootmem)
+               find_early_table_space(end, use_pse, use_gbpages);
+
+       for (i = 0; i < nr_range; i++)
+               ret = kernel_physical_mapping_init(mr[i].start, mr[i].end,
+                                                  mr[i].page_size_mask);
+
+#ifdef CONFIG_X86_32
+       early_ioremap_page_table_range_init();
+
+       load_cr3(swapper_pg_dir);
+#endif
+
+#ifdef CONFIG_X86_64
+       if (!after_bootmem && !start) {
+               pud_t *pud;
+               pmd_t *pmd;
+
+               mmu_cr4_features = read_cr4();
+
+               /*
+                * _brk_end cannot change anymore, but it and _end may be
+                * located on different 2M pages. cleanup_highmap(), however,
+                * can only consider _end when it runs, so destroy any
+                * mappings beyond _brk_end here.
+                */
+               pud = pud_offset(pgd_offset_k(_brk_end), _brk_end);
+               pmd = pmd_offset(pud, _brk_end - 1);
+               while (++pmd <= pmd_offset(pud, (unsigned long)_end - 1))
+                       pmd_clear(pmd);
+       }
+#endif
+       __flush_tlb_all();
+
+       if (!after_bootmem && e820_table_end > e820_table_start)
+               reserve_early(e820_table_start << PAGE_SHIFT,
+                                e820_table_end << PAGE_SHIFT, "PGTABLE");
+
+       if (!after_bootmem)
+               early_memtest(start, end);
+
+       return ret >> PAGE_SHIFT;
+}
+
+
+/*
+ * devmem_is_allowed() checks to see if /dev/mem access to a certain address
+ * is valid. The argument is a physical page number.
+ *
+ *
+ * On x86, access has to be given to the first megabyte of ram because that area
+ * contains bios code and data regions used by X and dosemu and similar apps.
+ * Access has to be given to non-kernel-ram areas as well, these contain the PCI
+ * mmio resources as well as potential bios/acpi data regions.
+ */
+int devmem_is_allowed(unsigned long pagenr)
+{
+       if (pagenr <= 256)
+               return 1;
+       if (iomem_is_exclusive(pagenr << PAGE_SHIFT))
+               return 0;
+       if (!page_is_ram(pagenr))
+               return 1;
+       return 0;
+}
 
 void free_init_pages(char *what, unsigned long begin, unsigned long end)
 {
-       unsigned long addr = begin;
+       unsigned long addr;
+       unsigned long begin_aligned, end_aligned;
+
+       /* Make sure boundaries are page aligned */
+       begin_aligned = PAGE_ALIGN(begin);
+       end_aligned   = end & PAGE_MASK;
 
-       if (addr >= end)
+       if (WARN_ON(begin_aligned != begin || end_aligned != end)) {
+               begin = begin_aligned;
+               end   = end_aligned;
+       }
+
+       if (begin >= end)
                return;
 
+       addr = begin;
+
        /*
         * If debugging page accesses then do not free this memory but
         * mark them not present - any buggy init-section access will
@@ -18,7 +355,7 @@ void free_init_pages(char *what, unsigned long begin, unsigned long end)
         */
 #ifdef CONFIG_DEBUG_PAGEALLOC
        printk(KERN_INFO "debug: unmapping init memory %08lx..%08lx\n",
-               begin, PAGE_ALIGN(end));
+               begin, end);
        set_memory_np(begin, (end - begin) >> PAGE_SHIFT);
 #else
        /*
@@ -33,8 +370,7 @@ void free_init_pages(char *what, unsigned long begin, unsigned long end)
        for (; addr < end; addr += PAGE_SIZE) {
                ClearPageReserved(virt_to_page(addr));
                init_page_count(virt_to_page(addr));
-               memset((void *)(addr & ~(PAGE_SIZE-1)),
-                       POISON_FREE_INITMEM, PAGE_SIZE);
+               memset((void *)addr, POISON_FREE_INITMEM, PAGE_SIZE);
                free_page(addr);
                totalram_pages++;
        }
@@ -47,3 +383,19 @@ void free_initmem(void)
                        (unsigned long)(&__init_begin),
                        (unsigned long)(&__init_end));
 }
+
+#ifdef CONFIG_BLK_DEV_INITRD
+void free_initrd_mem(unsigned long start, unsigned long end)
+{
+       /*
+        * end could be not aligned, and We can not align that,
+        * decompresser could be confused by aligned initrd_end
+        * We already reserve the end partial page before in
+        *   - i386_start_kernel()
+        *   - x86_64_start_kernel()
+        *   - relocate_initrd()
+        * So here We can do PAGE_ALIGN() safely to get partial page to be freed
+        */
+       free_init_pages("initrd memory", start, PAGE_ALIGN(end));
+}
+#endif