acpi: switch to dynamic mapping at SYS_STATE_boot

We can switch ACPI from using fixmap to dynamic mapping as soon as
the system enters SYS_STATE_boot. This will allow us, for example,
to map MADT on systems with large number of processors where the
table might not fit into NUM_FIXMAP_ACPI_PAGES (currently set to 4).

To avoid having a window between system entering SYS_STATE_boot and
vmap area being initialized move vm_init() a little higher.

Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>

xen/arch/x86/setup.c

@@ -1376,9 +1376,10 @@ void __init noreturn __start_xen(unsigned long mbi_p)
     else
         end_boot_allocator();
 
+    vm_init();
+
     system_state = SYS_STATE_boot;
 
-    vm_init();
     console_init_ring();
     vesa_init();
 

xen/drivers/acpi/osl.c

@@ -89,7 +89,7 @@ acpi_physical_address __init acpi_os_get_root_pointer(void)
 void __iomem *
 acpi_os_map_memory(acpi_physical_address phys, acpi_size size)
 {
-	if (system_state >= SYS_STATE_active) {
+	if (system_state >= SYS_STATE_boot) {
 		mfn_t mfn = _mfn(PFN_DOWN(phys));
 		unsigned int offs = phys & (PAGE_SIZE - 1);
 
@@ -104,7 +104,7 @@ acpi_os_map_memory(acpi_physical_address phys, acpi_size size)
 
 void acpi_os_unmap_memory(void __iomem * virt, acpi_size size)
 {
-	if (system_state >= SYS_STATE_active)
+	if (system_state >= SYS_STATE_boot)
 		vunmap((void *)((unsigned long)virt & PAGE_MASK));
 }