x86: e820 merge parsing of the mem=/memmap= boot parameters

since we now have 32-bit support for e820_register_active_regions(),
we can merge the parsing of the mem=/memmap= boot parameters.

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

1 files changed, 86 insertions, 0 deletions

diff --git a/arch/x86/kernel/e820.c b/arch/x86/kernel/e820.c
index 68aba413d403..4f2cd5d179e2 100644
--- a/arch/x86/kernel/e820.c
+++ b/arch/x86/kernel/e820.c
@@ -890,3 +890,89 @@ u64 __init e820_hole_size(u64 start, u64 end)
         }
         return end - start - ((u64)ram << PAGE_SHIFT);
 }
+
+static void early_panic(char *msg)
+{
+        early_printk(msg);
+        panic(msg);
+}
+
+/* "mem=nopentium" disables the 4MB page tables. */
+static int __init parse_memopt(char *p)
+{
+        u64 mem_size;
+
+        if (!p)
+                return -EINVAL;
+
+#ifdef CONFIG_X86_32
+        if (!strcmp(p, "nopentium")) {
+                setup_clear_cpu_cap(X86_FEATURE_PSE);
+                return 0;
+        }
+#endif
+
+        mem_size = memparse(p, &p);
+        end_user_pfn = mem_size>>PAGE_SHIFT;
+        return 0;
+}
+early_param("mem", parse_memopt);
+
+static int userdef __initdata;
+
+static int __init parse_memmap_opt(char *p)
+{
+        char *oldp;
+        u64 start_at, mem_size;
+
+        if (!strcmp(p, "exactmap")) {
+#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.
+                 */
+                e820_register_active_regions(0, 0, -1UL);
+                saved_max_pfn = e820_end_of_ram();
+                remove_all_active_ranges();
+#endif
+                e820.nr_map = 0;
+                userdef = 1;
+                return 0;
+        }
+
+        oldp = p;
+        mem_size = memparse(p, &p);
+        if (p == oldp)
+                return -EINVAL;
+
+        userdef = 1;
+        if (*p == '@') {
+                start_at = memparse(p+1, &p);
+                add_memory_region(start_at, mem_size, E820_RAM);
+        } else if (*p == '#') {
+                start_at = memparse(p+1, &p);
+                add_memory_region(start_at, mem_size, E820_ACPI);
+        } else if (*p == '$') {
+                start_at = memparse(p+1, &p);
+                add_memory_region(start_at, mem_size, E820_RESERVED);
+        } else {
+                end_user_pfn = (mem_size >> PAGE_SHIFT);
+        }
+        return *p == '\0' ? 0 : -EINVAL;
+}
+early_param("memmap", parse_memmap_opt);
+
+void __init finish_e820_parsing(void)
+{
+        if (userdef) {
+                int nr = e820.nr_map;
+
+                if (sanitize_e820_map(e820.map, ARRAY_SIZE(e820.map), &nr) < 0)
+                        early_panic("Invalid user supplied memory map");
+                e820.nr_map = nr;
+
+                printk(KERN_INFO "user-defined physical RAM map:\n");
+                e820_print_map("user");
+        }
+}