sbxxx: Handle active IMCs in AMD chipsets

Detect and temporarily disable the IMC while accessing the flash.
Disable writes on default, but allow the user to enforce it.

Corresponding to flashrom svn r1704.

Signed-off-by: Rudolf Marek <r.marek@assembler.cz>
Signed-off-by: Stefan Tauner <stefan.tauner@alumni.tuwien.ac.at>
Acked-by: Stefan Tauner <stefan.tauner@alumni.tuwien.ac.at>
Acked-by: David Hendricks <dhendrix@google.com>

1 files changed, 159 insertions, 0 deletions

diff --git a/amd_imc.c b/amd_imc.c
new file mode 100644
index 0000000..b05390c
--- /dev/null
+++ b/amd_imc.c
@@ -0,0 +1,159 @@
+/*
+ * This file is part of the flashrom project.
+ *
+ * Copyright (C) 2013 Rudolf Marek <r.marek@assembler.cz>
+ * Copyright (C) 2013 Stefan Tauner
+ *
+ * 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
+ * (at your option) 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 St, Fifth Floor, Boston, MA  02110-1301 USA
+ */
+
+#if defined(__i386__) || defined(__x86_64__)
+
+#include "flash.h"
+#include "programmer.h"
+#include "hwaccess.h"
+#include "spi.h"
+
+/* same as serverengines */
+static void enter_conf_mode_ec(uint16_t port)
+{
+	OUTB(0x5a, port);
+}
+
+static void exit_conf_mode_ec(uint16_t port)
+{
+	OUTB(0xa5, port);
+}
+
+static uint16_t get_sio_port(struct pci_dev *dev)
+{
+	uint16_t ec_port;
+
+	if (!dev) {
+		return 0;
+	}
+
+	ec_port = pci_read_word(dev, 0xa4);
+
+	/* EcPortActive? */
+	if (!(ec_port & 0x1))
+		return 0;
+
+	ec_port &= ~0x1;
+
+	return ec_port;
+}
+
+/* Wait for up to 10 ms for a response. */
+static int mbox_wait_ack(uint16_t mbox_port)
+{
+	int i = 10;
+	while (sio_read(mbox_port, 0x82) != 0xfa) {
+		if (--i == 0) {
+			msg_pwarn("IMC MBOX: Timeout!\n");
+			return 1;
+		}
+		programmer_delay(1000);
+	}
+	return 0;
+}
+
+static uint16_t mbox_get_port(uint16_t sio_port)
+{
+	uint16_t mbox_port;
+
+	enter_conf_mode_ec(sio_port);
+
+	/* Go to LDN 9, mailbox */
+	sio_write(sio_port, 7, 9);
+
+	/* MBOX inactive? */
+	if ((sio_read(sio_port, 0x30) & 1) == 0) {
+		exit_conf_mode_ec(sio_port);
+		return 0;
+	}
+
+	mbox_port = sio_read(sio_port, 0x60) << 8;
+	mbox_port |= sio_read(sio_port, 0x61);
+
+	exit_conf_mode_ec(sio_port);
+	return mbox_port;
+}
+
+/* Returns negative values when IMC is inactive, positive values on errors */
+static int imc_send_cmd(struct pci_dev *dev, uint8_t cmd)
+{
+	uint16_t sio_port;
+	uint16_t mbox_port;
+
+	/* IntegratedEcPresent? */
+	if (!(pci_read_byte(dev, 0x40) & (1 << 7)))
+		return -1;
+
+	sio_port = get_sio_port(dev);
+	if (!sio_port)
+		return -1;
+
+	msg_pdbg2("IMC SIO is at 0x%x.\n", sio_port);
+	mbox_port = mbox_get_port(sio_port);
+	if (!mbox_port)
+		return -1;
+	msg_pdbg2("IMC MBOX is at 0x%x.\n", mbox_port);
+
+	sio_write(mbox_port, 0x82, 0x0);
+	sio_write(mbox_port, 0x83, cmd);
+	sio_write(mbox_port, 0x84, 0x0);
+	/* trigger transfer 0x96 with subcommand cmd */
+	sio_write(mbox_port, 0x80, 0x96);
+
+	return mbox_wait_ack(mbox_port);
+}
+
+static int imc_resume(void *data)
+{
+	struct pci_dev *dev = data;
+	int ret = imc_send_cmd(dev, 0xb5);
+
+	if (ret != 0)
+		msg_pinfo("Resuming IMC failed)\n");
+	else
+		msg_pdbg2("IMC resumed.\n");
+	return ret;
+}
+
+int amd_imc_shutdown(struct pci_dev *dev)
+{
+	/* Try to put IMC to sleep */
+	int ret = imc_send_cmd(dev, 0xb4);
+
+	/* No IMC activity detectable, assume we are fine */
+	if (ret < 0) {
+		msg_pdbg2("No IMC found.\n");
+		return 0;
+	}
+
+	if (ret != 0) {
+		msg_perr("Shutting down IMC failed.\n");
+		return ret;
+	}
+	msg_pdbg2("Shutting down IMC successful.\n");
+
+	if (register_shutdown(imc_resume, dev))
+		return 1;
+
+	return ret;
+}
+
+#endif