ACPI: Add S4BIOS support (Pavel Machek)

arch/i386/kernel/acpi/wakeup.S

@@ -319,6 +319,31 @@ ret_point:
 	pushl saved_context_eflags ; popfl
 	ret
 
+ENTRY(do_suspend_lowlevel_s4bios)
+	cmpl $0,4(%esp)
+	jne ret_point
+	call save_processor_state
+
+	movl %esp, saved_context_esp
+	movl %eax, saved_context_eax
+	movl %ebx, saved_context_ebx
+	movl %ecx, saved_context_ecx
+	movl %edx, saved_context_edx
+	movl %ebp, saved_context_ebp
+	movl %esi, saved_context_esi
+	movl %edi, saved_context_edi
+	pushfl ; popl saved_context_eflags
+
+	movl $ret_point,saved_eip
+	movl %esp,saved_esp
+	movl %ebp,saved_ebp
+	movl %ebx,saved_ebx
+	movl %edi,saved_edi
+	movl %esi,saved_esi
+
+	call acpi_enter_sleep_state_s4bios
+	ret
+
 ALIGN
 # saved registers
 saved_gdt:	.long	0,0

drivers/acpi/hardware/hwsleep.c

@@ -335,6 +335,51 @@ acpi_enter_sleep_state (
 	return_ACPI_STATUS (AE_OK);
 }
 
+
+/******************************************************************************
+ *
+ * FUNCTION:    acpi_enter_sleep_state_s4bios
+ *
+ * PARAMETERS:  None
+ *
+ * RETURN:      Status
+ *
+ * DESCRIPTION: Perform a S4 bios request.
+ *              THIS FUNCTION MUST BE CALLED WITH INTERRUPTS DISABLED
+ *
+ ******************************************************************************/
+
+acpi_status
+acpi_enter_sleep_state_s4bios (
+	void)
+{
+	u32                             in_value;
+	acpi_status                     status;
+
+
+	ACPI_FUNCTION_TRACE ("acpi_enter_sleep_state_s4bios");
+
+	acpi_set_register (ACPI_BITREG_WAKE_STATUS, 1, ACPI_MTX_LOCK);
+	acpi_hw_clear_acpi_status();
+
+	acpi_hw_disable_non_wakeup_gpes();
+
+	ACPI_FLUSH_CPU_CACHE();
+
+	status = acpi_os_write_port (acpi_gbl_FADT->smi_cmd, (acpi_integer) acpi_gbl_FADT->S4bios_req, 8);
+
+	do {
+		acpi_os_stall(1000);
+		status = acpi_get_register (ACPI_BITREG_WAKE_STATUS, &in_value, ACPI_MTX_LOCK);
+		if (ACPI_FAILURE (status)) {
+			return_ACPI_STATUS (status);
+		}
+	} while (!in_value);
+
+	return_ACPI_STATUS (AE_OK);
+}
+
+
 /******************************************************************************
  *
  * FUNCTION:    acpi_leave_sleep_state