@@ -165,7 +165,7 @@ multipliers 'Kilo', 'Mega', and 'Giga', equalling 2^10, 2^20, and 2^30
 bytes respectively. Such letter suffixes can also be entirely omitted.
 
 
-	acpi=		[HW,ACPI,X86]
+	acpi=		[HW,ACPI,X86,ARM64]
 			Advanced Configuration and Power Interface
 			Format: { force | off | strict | noirq | rsdt }
 			force -- enable ACPI if default was off

@@ -175,6 +175,7 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
 				strictly ACPI specification compliant.
 			rsdt -- prefer RSDT over (default) XSDT
 			copy_dsdt -- copy DSDT to memory
+			For ARM64, ONLY "acpi=off" or "acpi=force" are available
 
 			See also Documentation/power/runtime_pm.txt, pci=noacpi
 

@@ -26,6 +26,13 @@ static inline void disable_acpi(void)
 	acpi_noirq = 1;
 }
 
+static inline void enable_acpi(void)
+{
+	acpi_disabled = 0;
+	acpi_pci_disabled = 0;
+	acpi_noirq = 0;
+}
+
 /*
  * It's used from ACPI core in kdump to boot UP system with SMP kernel,
  * with this check the ACPI core will not override the CPU index

@@ -40,6 +47,8 @@ static inline bool acpi_has_cpu_in_madt(void)
 
 static inline void arch_fix_phys_package_id(int num, u32 slot) { }
 
+#else
+static inline void disable_acpi(void) { }
 #endif /* CONFIG_ACPI */
 
 #endif /*_ASM_ACPI_H*/

@@ -67,3 +67,20 @@ void __init acpi_boot_table_init(void)
 	if (acpi_table_init())
 		disable_acpi();
 }
+
+static int __init parse_acpi(char *arg)
+{
+	if (!arg)
+		return -EINVAL;
+
+	/* "acpi=off" disables both ACPI table parsing and interpreter */
+	if (strcmp(arg, "off") == 0)
+		disable_acpi();
+	else if (strcmp(arg, "force") == 0) /* force ACPI to be enabled */
+		enable_acpi();
+	else
+		return -EINVAL;	/* Core will print when we return error */
+
+	return 0;
+}
+early_param("acpi", parse_acpi);

@@ -60,6 +60,7 @@
 #include <asm/memblock.h>
 #include <asm/psci.h>
 #include <asm/efi.h>
+#include <asm/acpi.h>
 
 unsigned int processor_id;
 EXPORT_SYMBOL(processor_id);

@@ -384,6 +385,8 @@ void __init setup_arch(char **cmdline_p)
 
 	early_ioremap_init();
 
+	disable_acpi();
+
 	parse_early_param();
 
 	efi_init();