[PATCH] i386: Move e820/efi memmap walking code to e820.c

This patch moves e820/efi memmap table walking function from
setup.c to e820.c, also this patch adds extern declaration in
header file.

Signed-off-by: bibo,mao <bibo.mao@intel.com>
Signed-off-by: Andi Kleen <ak@suse.de>

 arch/i386/kernel/e820.c  |  115 +++++++++++++++++++++++++++++++++
 arch/i386/kernel/setup.c |  118 -----------------------------------
 include/asm-i386/e820.h  |    2
 arch/i386/kernel/e820.c  |  115 +++++++++++++++++++++++++++++++++++++++++++++
 arch/i386/kernel/setup.c |  118 -----------------------------------------------
 include/asm-i386/e820.h  |    2
 3 files changed, 117 insertions(+), 118 deletions(-)

1 files changed, 115 insertions, 0 deletions

diff --git a/arch/i386/kernel/e820.c b/arch/i386/kernel/e820.c
index be4934f6f85b..47c495bf0cbc 100644
--- a/arch/i386/kernel/e820.c
+++ b/arch/i386/kernel/e820.c
@@ -28,6 +28,11 @@ static struct change_member change_point_list[2*E820MAX] __initdata;
 static struct change_member *change_point[2*E820MAX] __initdata;
 static struct e820entry *overlap_list[E820MAX] __initdata;
 static struct e820entry new_bios[E820MAX] __initdata;
+/* For PCI or other memory-mapped resources */
+unsigned long pci_mem_start = 0x10000000;
+#ifdef CONFIG_PCI
+EXPORT_SYMBOL(pci_mem_start);
+#endif
 struct resource data_resource = {
         .name   = "Kernel data",
         .start  = 0,
@@ -591,3 +596,113 @@ void __init find_max_pfn(void)
                 memory_present(0, start, end);
         }
 }
+
+/*
+ * Free all available memory for boot time allocation.  Used
+ * as a callback function by efi_memory_walk()
+ */
+
+static int __init
+free_available_memory(unsigned long start, unsigned long end, void *arg)
+{
+        /* check max_low_pfn */
+        if (start >= (max_low_pfn << PAGE_SHIFT))
+                return 0;
+        if (end >= (max_low_pfn << PAGE_SHIFT))
+                end = max_low_pfn << PAGE_SHIFT;
+        if (start < end)
+                free_bootmem(start, end - start);
+
+        return 0;
+}
+/*
+ * Register fully available low RAM pages with the bootmem allocator.
+ */
+void __init register_bootmem_low_pages(unsigned long max_low_pfn)
+{
+        int i;
+
+        if (efi_enabled) {
+                efi_memmap_walk(free_available_memory, NULL);
+                return;
+        }
+        for (i = 0; i < e820.nr_map; i++) {
+                unsigned long curr_pfn, last_pfn, size;
+                /*
+                 * Reserve usable low memory
+                 */
+                if (e820.map[i].type != E820_RAM)
+                        continue;
+                /*
+                 * We are rounding up the start address of usable memory:
+                 */
+                curr_pfn = PFN_UP(e820.map[i].addr);
+                if (curr_pfn >= max_low_pfn)
+                        continue;
+                /*
+                 * ... and at the end of the usable range downwards:
+                 */
+                last_pfn = PFN_DOWN(e820.map[i].addr + e820.map[i].size);
+
+                if (last_pfn > max_low_pfn)
+                        last_pfn = max_low_pfn;
+
+                /*
+                 * .. finally, did all the rounding and playing
+                 * around just make the area go away?
+                 */
+                if (last_pfn <= curr_pfn)
+                        continue;
+
+                size = last_pfn - curr_pfn;
+                free_bootmem(PFN_PHYS(curr_pfn), PFN_PHYS(size));
+        }
+}
+
+void __init register_memory(void)
+{
+        unsigned long gapstart, gapsize, round;
+        unsigned long long last;
+        int i;
+
+        /*
+         * Search for the bigest gap in the low 32 bits of the e820
+         * memory space.
+         */
+        last = 0x100000000ull;
+        gapstart = 0x10000000;
+        gapsize = 0x400000;
+        i = e820.nr_map;
+        while (--i >= 0) {
+                unsigned long long start = e820.map[i].addr;
+                unsigned long long end = start + e820.map[i].size;
+
+                /*
+                 * Since "last" is at most 4GB, we know we'll
+                 * fit in 32 bits if this condition is true
+                 */
+                if (last > end) {
+                        unsigned long gap = last - end;
+
+                        if (gap > gapsize) {
+                                gapsize = gap;
+                                gapstart = end;
+                        }
+                }
+                if (start < last)
+                        last = start;
+        }
+
+        /*
+         * See how much we want to round up: start off with
+         * rounding to the next 1MB area.
+         */
+        round = 0x100000;
+        while ((gapsize >> 4) > round)
+                round += round;
+        /* Fun with two's complement */
+        pci_mem_start = (gapstart + round) & -round;
+
+        printk("Allocating PCI resources starting at %08lx (gap: %08lx:%08lx)\n",
+                pci_mem_start, gapstart, gapsize);
+}