[acpi] Add support for ACPI power off

Signed-off-by: Michael Brown <mcb30@ipxe.org>

src/arch/x86/interface/pcbios/acpipwr.c

@@ -0,0 +1,116 @@
+/*
+ * Copyright (C) 2016 Michael Brown <mbrown@fensystems.co.uk>.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of the
+ * License, or any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
+ * 02110-1301, USA.
+ *
+ * You can also choose to distribute this program under the terms of
+ * the Unmodified Binary Distribution Licence (as given in the file
+ * COPYING.UBDL), provided that you have satisfied its requirements.
+ */
+
+FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );
+
+#include <errno.h>
+#include <byteswap.h>
+#include <realmode.h>
+#include <bios.h>
+#include <ipxe/io.h>
+#include <ipxe/acpi.h>
+#include <ipxe/acpipwr.h>
+
+/** @file
+ *
+ * ACPI power off
+ *
+ */
+
+/** Colour for debug messages */
+#define colour FADT_SIGNATURE
+
+/** _S5_ signature */
+#define S5_SIGNATURE ACPI_SIGNATURE ( '_', 'S', '5', '_' )
+
+/**
+ * Power off the computer using ACPI
+ *
+ * @ret rc		Return status code
+ */
+int acpi_poweroff ( void ) {
+	struct acpi_fadt fadtab;
+	uint16_t ebda;
+	userptr_t rsdt;
+	userptr_t fadt;
+	unsigned int pm1a_cnt_blk;
+	unsigned int pm1b_cnt_blk;
+	unsigned int pm1a_cnt;
+	unsigned int pm1b_cnt;
+	unsigned int slp_typa;
+	unsigned int slp_typb;
+	int s5;
+	int rc;
+
+	/* Locate EBDA */
+	get_real ( ebda, BDA_SEG, BDA_EBDA );
+
+	/* Locate RSDT */
+	rsdt = acpi_find_rsdt ( real_to_user ( ebda, 0 ) );
+	if ( ! rsdt ) {
+		DBGC ( colour, "ACPI could not find RSDT (EBDA %04x)\n", ebda );
+		return -ENOENT;
+	}
+
+	/* Locate FADT */
+	fadt = acpi_find ( rsdt, FADT_SIGNATURE, 0 );
+	if ( ! fadt ) {
+		DBGC ( colour, "ACPI could not find FADT\n" );
+		return -ENOENT;
+	}
+
+	/* Read FADT */
+	copy_from_user ( &fadtab, fadt, 0, sizeof ( fadtab ) );
+	pm1a_cnt_blk = le32_to_cpu ( fadtab.pm1a_cnt_blk );
+	pm1b_cnt_blk = le32_to_cpu ( fadtab.pm1b_cnt_blk );
+	pm1a_cnt = ( pm1a_cnt_blk + ACPI_PM1_CNT );
+	pm1b_cnt = ( pm1b_cnt_blk + ACPI_PM1_CNT );
+
+	/* Extract \_S5 from DSDT or any SSDT */
+	s5 = acpi_sx ( rsdt, S5_SIGNATURE );
+	if ( s5 < 0 ) {
+		rc = s5;
+		DBGC ( colour, "ACPI could not extract \\_S5: %s\n",
+		       strerror ( rc ) );
+		return rc;
+	}
+
+	/* Power off system */
+	if ( pm1a_cnt_blk ) {
+		slp_typa = ( ( s5 >> 0 ) & 0xff );
+		DBGC ( colour, "ACPI PM1a sleep type %#x => %04x\n",
+		       slp_typa, pm1a_cnt );
+		outw ( ( ACPI_PM1_CNT_SLP_TYP ( slp_typa ) |
+			 ACPI_PM1_CNT_SLP_EN ), pm1a_cnt );
+	}
+	if ( pm1b_cnt_blk ) {
+		slp_typb = ( ( s5 >> 8 ) & 0xff );
+		DBGC ( colour, "ACPI PM1b sleep type %#x => %04x\n",
+		       slp_typb, pm1b_cnt );
+		outw ( ( ACPI_PM1_CNT_SLP_TYP ( slp_typb ) |
+			 ACPI_PM1_CNT_SLP_EN ), pm1b_cnt );
+	}
+
+	DBGC ( colour, "ACPI power off failed\n" );
+	return -EPROTO;
+}

src/arch/x86/interface/pcbios/apm.c

@@ -32,14 +32,14 @@ FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );
 
 #include <errno.h>
 #include <realmode.h>
-#include <ipxe/reboot.h>
+#include <ipxe/apm.h>
 
 /**
  * Power off the computer using APM
  *
  * @ret rc		Return status code
  */
-static int apm_poweroff ( void ) {
+int apm_poweroff ( void ) {
 	uint16_t apm_version;
 	uint16_t apm_signature;
 	uint16_t apm_flags;
@@ -108,5 +108,3 @@ static int apm_poweroff ( void ) {
 	/* Should never happen */
 	return -ECANCELED;
 }
-
-PROVIDE_REBOOT ( pcbios, poweroff, apm_poweroff );

src/arch/x86/interface/pcbios/bios_reboot.c

@@ -32,6 +32,8 @@ FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );
 #include <ipxe/reboot.h>
 #include <realmode.h>
 #include <bios.h>
+#include <ipxe/apm.h>
+#include <ipxe/acpipwr.h>
 
 /**
  * Reboot system
@@ -49,4 +51,24 @@ static void bios_reboot ( int warm ) {
 	__asm__ __volatile__ ( REAL_CODE ( "ljmp $0xf000, $0xfff0" ) );
 }
 
+/**
+ * Power off system
+ *
+ * @ret rc		Return status code
+ */
+static int bios_poweroff ( void ) {
+	int rc;
+
+	/* Try APM */
+	if ( ( rc = apm_poweroff() ) != 0 )
+		DBG ( "APM power off failed: %s\n", strerror ( rc ) );
+
+	/* Try ACPI */
+	if ( ( rc = acpi_poweroff() ) != 0 )
+		DBG ( "ACPI power off failed: %s\n", strerror ( rc ) );
+
+	return rc;
+}
+
 PROVIDE_REBOOT ( pcbios, reboot, bios_reboot );
+PROVIDE_REBOOT ( pcbios, poweroff, bios_poweroff );