x86: Make sure wakeup trampoline code is below 1MB

Instead of using bootmem, try find_e820_area()/reserve_early(),
and call acpi_reserve_memory() early, to allocate the wakeup
trampoline code area below 1M.

This is more reliable, and it also removes a dependency on
bootmem.

-v2: change function name to acpi_reserve_wakeup_memory(),
     as suggested by Rafael.

Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Acked-by: H. Peter Anvin <hpa@zytor.com>
Acked-by: Rafael J. Wysocki <rjw@sisk.pl>
Cc: pm list <linux-pm@lists.linux-foundation.org>
Cc: Len Brown <lenb@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
LKML-Reference: <4AFA210B.3020207@kernel.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 9 insertions, 6 deletions

diff --git a/arch/x86/kernel/acpi/sleep.c b/arch/x86/kernel/acpi/sleep.c
index ca93638ba430..4a411450dfa0 100644
--- a/arch/x86/kernel/acpi/sleep.c
+++ b/arch/x86/kernel/acpi/sleep.c
@@ -119,29 +119,32 @@ void acpi_restore_state_mem(void)
 
 
 /**
- * acpi_reserve_bootmem - do _very_ early ACPI initialisation
+ * acpi_reserve_wakeup_memory - do _very_ early ACPI initialisation
  *
  * We allocate a page from the first 1MB of memory for the wakeup
  * routine for when we come back from a sleep state. The
  * runtime allocator allows specification of <16MB pages, but not
  * <1MB pages.
  */
-void __init acpi_reserve_bootmem(void)
+void __init acpi_reserve_wakeup_memory(void)
 {
+        unsigned long mem;
+
         if ((&wakeup_code_end - &wakeup_code_start) > WAKEUP_SIZE) {
                 printk(KERN_ERR
                        "ACPI: Wakeup code way too big, S3 disabled.\n");
                 return;
         }
 
-        acpi_realmode = (unsigned long)alloc_bootmem_low(WAKEUP_SIZE);
+        mem = find_e820_area(0, 1<<20, WAKEUP_SIZE, PAGE_SIZE);
 
-        if (!acpi_realmode) {
+        if (mem == -1L) {
                 printk(KERN_ERR "ACPI: Cannot allocate lowmem, S3 disabled.\n");
                 return;
         }
-
-        acpi_wakeup_address = virt_to_phys((void *)acpi_realmode);
+        acpi_realmode = (unsigned long) phys_to_virt(mem);
+        acpi_wakeup_address = mem;
+        reserve_early(mem, mem + WAKEUP_SIZE, "ACPI WAKEUP");
 }