aboutsummaryrefslogtreecommitdiff
path: root/arch/i386/kernel/e820.c
diff options
context:
space:
mode:
Diffstat (limited to 'arch/i386/kernel/e820.c')
-rw-r--r--arch/i386/kernel/e820.c152
1 files changed, 152 insertions, 0 deletions
diff --git a/arch/i386/kernel/e820.c b/arch/i386/kernel/e820.c
index 47c495bf0cb..b755255f272 100644
--- a/arch/i386/kernel/e820.c
+++ b/arch/i386/kernel/e820.c
@@ -33,6 +33,7 @@ unsigned long pci_mem_start = 0x10000000;
#ifdef CONFIG_PCI
EXPORT_SYMBOL(pci_mem_start);
#endif
+extern int user_defined_memmap;
struct resource data_resource = {
.name = "Kernel data",
.start = 0,
@@ -706,3 +707,154 @@ void __init register_memory(void)
printk("Allocating PCI resources starting at %08lx (gap: %08lx:%08lx)\n",
pci_mem_start, gapstart, gapsize);
}
+
+void __init print_memory_map(char *who)
+{
+ int i;
+
+ for (i = 0; i < e820.nr_map; i++) {
+ printk(" %s: %016Lx - %016Lx ", who,
+ e820.map[i].addr,
+ e820.map[i].addr + e820.map[i].size);
+ switch (e820.map[i].type) {
+ case E820_RAM: printk("(usable)\n");
+ break;
+ case E820_RESERVED:
+ printk("(reserved)\n");
+ break;
+ case E820_ACPI:
+ printk("(ACPI data)\n");
+ break;
+ case E820_NVS:
+ printk("(ACPI NVS)\n");
+ break;
+ default: printk("type %lu\n", e820.map[i].type);
+ break;
+ }
+ }
+}
+
+void __init limit_regions(unsigned long long size)
+{
+ unsigned long long current_addr = 0;
+ int i;
+
+ print_memory_map("limit_regions start");
+ if (efi_enabled) {
+ efi_memory_desc_t *md;
+ void *p;
+
+ for (p = memmap.map, i = 0; p < memmap.map_end;
+ p += memmap.desc_size, i++) {
+ md = p;
+ current_addr = md->phys_addr + (md->num_pages << 12);
+ if (md->type == EFI_CONVENTIONAL_MEMORY) {
+ if (current_addr >= size) {
+ md->num_pages -=
+ (((current_addr-size) + PAGE_SIZE-1) >> PAGE_SHIFT);
+ memmap.nr_map = i + 1;
+ return;
+ }
+ }
+ }
+ }
+ for (i = 0; i < e820.nr_map; i++) {
+ current_addr = e820.map[i].addr + e820.map[i].size;
+ if (current_addr < size)
+ continue;
+
+ if (e820.map[i].type != E820_RAM)
+ continue;
+
+ if (e820.map[i].addr >= size) {
+ /*
+ * This region starts past the end of the
+ * requested size, skip it completely.
+ */
+ e820.nr_map = i;
+ } else {
+ e820.nr_map = i + 1;
+ e820.map[i].size -= current_addr - size;
+ }
+ print_memory_map("limit_regions endfor");
+ return;
+ }
+ print_memory_map("limit_regions endfunc");
+}
+
+ /*
+ * This function checks if the entire range <start,end> is mapped with type.
+ *
+ * Note: this function only works correct if the e820 table is sorted and
+ * not-overlapping, which is the case
+ */
+int __init
+e820_all_mapped(unsigned long s, unsigned long e, unsigned type)
+{
+ u64 start = s;
+ u64 end = e;
+ int i;
+ for (i = 0; i < e820.nr_map; i++) {
+ struct e820entry *ei = &e820.map[i];
+ if (type && ei->type != type)
+ continue;
+ /* is the region (part) in overlap with the current region ?*/
+ if (ei->addr >= end || ei->addr + ei->size <= start)
+ continue;
+ /* if the region is at the beginning of <start,end> we move
+ * start to the end of the region since it's ok until there
+ */
+ if (ei->addr <= start)
+ start = ei->addr + ei->size;
+ /* if start is now at or beyond end, we're done, full
+ * coverage */
+ if (start >= end)
+ return 1; /* we're done */
+ }
+ return 0;
+}
+
+static int __init parse_memmap(char *arg)
+{
+ if (!arg)
+ return -EINVAL;
+
+ if (strcmp(arg, "exactmap") == 0) {
+#ifdef CONFIG_CRASH_DUMP
+ /* If we are doing a crash dump, we
+ * still need to know the real mem
+ * size before original memory map is
+ * reset.
+ */
+ find_max_pfn();
+ saved_max_pfn = max_pfn;
+#endif
+ e820.nr_map = 0;
+ user_defined_memmap = 1;
+ } else {
+ /* If the user specifies memory size, we
+ * limit the BIOS-provided memory map to
+ * that size. exactmap can be used to specify
+ * the exact map. mem=number can be used to
+ * trim the existing memory map.
+ */
+ unsigned long long start_at, mem_size;
+
+ mem_size = memparse(arg, &arg);
+ if (*arg == '@') {
+ start_at = memparse(arg+1, &arg);
+ add_memory_region(start_at, mem_size, E820_RAM);
+ } else if (*arg == '#') {
+ start_at = memparse(arg+1, &arg);
+ add_memory_region(start_at, mem_size, E820_ACPI);
+ } else if (*arg == '$') {
+ start_at = memparse(arg+1, &arg);
+ add_memory_region(start_at, mem_size, E820_RESERVED);
+ } else {
+ limit_regions(mem_size);
+ user_defined_memmap = 1;
+ }
+ }
+ return 0;
+}
+early_param("memmap", parse_memmap);