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Commit 6a11e5c6 authored by Jeremy Kerr's avatar Jeremy Kerr Committed by Corey Minyard
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drivers/char/ipmi: Add powernv IPMI driver 



This change adds an initial IPMI driver for powerpc OPAL firmware. The
interface is exposed entirely through firmware: we have two functions to
send and receive IPMI messages, and an interrupt notification from the
firmware to signify that a message is available.

Signed-off-by: default avatarJeremy Kerr <jk@ozlabs.org>
Signed-off-by: default avatarCorey Minyard <cminyard@mvista.com>
parent 25930707

drivers/char/ipmi/Kconfig

+6 −0
Original line number Diff line number Diff line
@@ -70,6 +70,12 @@ config IPMI_SSIF 
	 have a driver that must be accessed over an I2C bus instead of a

	 standard interface.  This module requires I2C support.



config IPMI_POWERNV

       depends on PPC_POWERNV

       tristate 'POWERNV (OPAL firmware) IPMI interface'

       help

         Provides a driver for OPAL firmware-based IPMI interfaces.



config IPMI_WATCHDOG

       tristate 'IPMI Watchdog Timer'

       help

drivers/char/ipmi/Makefile

+1 −0
Original line number Diff line number Diff line
@@ -8,5 +8,6 @@ obj-$(CONFIG_IPMI_HANDLER) += ipmi_msghandler.o 
obj-$(CONFIG_IPMI_DEVICE_INTERFACE) += ipmi_devintf.o

obj-$(CONFIG_IPMI_SI) += ipmi_si.o

obj-$(CONFIG_IPMI_SSIF) += ipmi_ssif.o

obj-$(CONFIG_IPMI_POWERNV) += ipmi_powernv.o

obj-$(CONFIG_IPMI_WATCHDOG) += ipmi_watchdog.o

obj-$(CONFIG_IPMI_POWEROFF) += ipmi_poweroff.o

drivers/char/ipmi/ipmi_powernv.c

0 → 100644
+310 −0
Original line number Diff line number Diff line 
/*

 * PowerNV OPAL IPMI driver

 *

 * Copyright 2014 IBM Corp.

 *

 * 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.

 */



#define pr_fmt(fmt)        "ipmi-powernv: " fmt



#include <linux/ipmi_smi.h>

#include <linux/list.h>

#include <linux/module.h>

#include <linux/of.h>



#include <asm/opal.h>





struct ipmi_smi_powernv {

	u64			interface_id;

	struct ipmi_device_id	ipmi_id;

	ipmi_smi_t		intf;

	u64			event;

	struct notifier_block	event_nb;



	/**

	 * We assume that there can only be one outstanding request, so

	 * keep the pending message in cur_msg. We protect this from concurrent

	 * updates through send & recv calls, (and consequently opal_msg, which

	 * is in-use when cur_msg is set) with msg_lock

	 */

	spinlock_t		msg_lock;

	struct ipmi_smi_msg	*cur_msg;

	struct opal_ipmi_msg	*opal_msg;

};



static int ipmi_powernv_start_processing(void *send_info, ipmi_smi_t intf)

{

	struct ipmi_smi_powernv *smi = send_info;



	smi->intf = intf;

	return 0;

}



static void send_error_reply(struct ipmi_smi_powernv *smi,

		struct ipmi_smi_msg *msg, u8 completion_code)

{

	msg->rsp[0] = msg->data[0] | 0x4;

	msg->rsp[1] = msg->data[1];

	msg->rsp[2] = completion_code;

	msg->rsp_size = 3;

	ipmi_smi_msg_received(smi->intf, msg);

}



static void ipmi_powernv_send(void *send_info, struct ipmi_smi_msg *msg)

{

	struct ipmi_smi_powernv *smi = send_info;

	struct opal_ipmi_msg *opal_msg;

	unsigned long flags;

	int comp, rc;

	size_t size;



	/* ensure data_len will fit in the opal_ipmi_msg buffer... */

	if (msg->data_size > IPMI_MAX_MSG_LENGTH) {

		comp = IPMI_REQ_LEN_EXCEEDED_ERR;

		goto err;

	}



	/* ... and that we at least have netfn and cmd bytes */

	if (msg->data_size < 2) {

		comp = IPMI_REQ_LEN_INVALID_ERR;

		goto err;

	}



	spin_lock_irqsave(&smi->msg_lock, flags);



	if (smi->cur_msg) {

		comp = IPMI_NODE_BUSY_ERR;

		goto err_unlock;

	}



	/* format our data for the OPAL API */

	opal_msg = smi->opal_msg;

	opal_msg->version = OPAL_IPMI_MSG_FORMAT_VERSION_1;

	opal_msg->netfn = msg->data[0];

	opal_msg->cmd = msg->data[1];

	if (msg->data_size > 2)

		memcpy(opal_msg->data, msg->data + 2, msg->data_size - 2);



	/* data_size already includes the netfn and cmd bytes */

	size = sizeof(*opal_msg) + msg->data_size - 2;



	pr_devel("%s: opal_ipmi_send(0x%llx, %p, %ld)\n", __func__,

			smi->interface_id, opal_msg, size);

	rc = opal_ipmi_send(smi->interface_id, opal_msg, size);

	pr_devel("%s:  -> %d\n", __func__, rc);



	if (!rc) {

		smi->cur_msg = msg;

		spin_unlock_irqrestore(&smi->msg_lock, flags);

		return;

	}



	comp = IPMI_ERR_UNSPECIFIED;

err_unlock:

	spin_unlock_irqrestore(&smi->msg_lock, flags);

err:

	send_error_reply(smi, msg, comp);

}



static int ipmi_powernv_recv(struct ipmi_smi_powernv *smi)

{

	struct opal_ipmi_msg *opal_msg;

	struct ipmi_smi_msg *msg;

	unsigned long flags;

	uint64_t size;

	int rc;



	pr_devel("%s: opal_ipmi_recv(%llx, msg, sz)\n", __func__,

			smi->interface_id);



	spin_lock_irqsave(&smi->msg_lock, flags);



	if (!smi->cur_msg) {

		pr_warn("no current message?\n");

		return 0;

	}



	msg = smi->cur_msg;

	opal_msg = smi->opal_msg;



	size = cpu_to_be64(sizeof(*opal_msg) + IPMI_MAX_MSG_LENGTH);



	rc = opal_ipmi_recv(smi->interface_id,

			opal_msg,

			&size);

	size = be64_to_cpu(size);

	pr_devel("%s:   -> %d (size %lld)\n", __func__,

			rc, rc == 0 ? size : 0);

	if (rc) {

		spin_unlock_irqrestore(&smi->msg_lock, flags);

		ipmi_free_smi_msg(msg);

		return 0;

	}



	if (size < sizeof(*opal_msg)) {

		spin_unlock_irqrestore(&smi->msg_lock, flags);

		pr_warn("unexpected IPMI message size %lld\n", size);

		return 0;

	}



	if (opal_msg->version != OPAL_IPMI_MSG_FORMAT_VERSION_1) {

		spin_unlock_irqrestore(&smi->msg_lock, flags);

		pr_warn("unexpected IPMI message format (version %d)\n",

				opal_msg->version);

		return 0;

	}



	msg->rsp[0] = opal_msg->netfn;

	msg->rsp[1] = opal_msg->cmd;

	if (size > sizeof(*opal_msg))

		memcpy(&msg->rsp[2], opal_msg->data, size - sizeof(*opal_msg));

	msg->rsp_size = 2 + size - sizeof(*opal_msg);



	smi->cur_msg = NULL;

	spin_unlock_irqrestore(&smi->msg_lock, flags);

	ipmi_smi_msg_received(smi->intf, msg);

	return 0;

}



static void ipmi_powernv_request_events(void *send_info)

{

}



static void ipmi_powernv_set_run_to_completion(void *send_info,

		bool run_to_completion)

{

}



static void ipmi_powernv_poll(void *send_info)

{

	struct ipmi_smi_powernv *smi = send_info;



	ipmi_powernv_recv(smi);

}



static struct ipmi_smi_handlers ipmi_powernv_smi_handlers = {

	.owner			= THIS_MODULE,

	.start_processing	= ipmi_powernv_start_processing,

	.sender			= ipmi_powernv_send,

	.request_events		= ipmi_powernv_request_events,

	.set_run_to_completion	= ipmi_powernv_set_run_to_completion,

	.poll			= ipmi_powernv_poll,

};



static int ipmi_opal_event(struct notifier_block *nb,

			  unsigned long events, void *change)

{

	struct ipmi_smi_powernv *smi = container_of(nb,

					struct ipmi_smi_powernv, event_nb);



	if (events & smi->event)

		ipmi_powernv_recv(smi);

	return 0;

}



static int ipmi_powernv_probe(struct platform_device *pdev)

{

	struct ipmi_smi_powernv *ipmi;

	struct device *dev;

	u32 prop;

	int rc;



	if (!pdev || !pdev->dev.of_node)

		return -ENODEV;



	dev = &pdev->dev;



	ipmi = devm_kzalloc(dev, sizeof(*ipmi), GFP_KERNEL);

	if (!ipmi)

		return -ENOMEM;



	spin_lock_init(&ipmi->msg_lock);



	rc = of_property_read_u32(dev->of_node, "ibm,ipmi-interface-id",

			&prop);

	if (rc) {

		dev_warn(dev, "No interface ID property\n");

		goto err_free;

	}

	ipmi->interface_id = prop;



	rc = of_property_read_u32(dev->of_node, "interrupts", &prop);

	if (rc) {

		dev_warn(dev, "No interrupts property\n");

		goto err_free;

	}



	ipmi->event = 1ull << prop;

	ipmi->event_nb.notifier_call = ipmi_opal_event;



	rc = opal_notifier_register(&ipmi->event_nb);

	if (rc) {

		dev_warn(dev, "OPAL notifier registration failed (%d)\n", rc);

		goto err_free;

	}



	ipmi->opal_msg = devm_kmalloc(dev,

			sizeof(*ipmi->opal_msg) + IPMI_MAX_MSG_LENGTH,

			GFP_KERNEL);

	if (!ipmi->opal_msg) {

		rc = -ENOMEM;

		goto err_unregister;

	}



	/* todo: query actual ipmi_device_id */

	rc = ipmi_register_smi(&ipmi_powernv_smi_handlers, ipmi,

			&ipmi->ipmi_id, dev, 0);

	if (rc) {

		dev_warn(dev, "IPMI SMI registration failed (%d)\n", rc);

		goto err_free_msg;

	}



	dev_set_drvdata(dev, ipmi);

	return 0;



err_free_msg:

	devm_kfree(dev, ipmi->opal_msg);

err_unregister:

	opal_notifier_unregister(&ipmi->event_nb);

err_free:

	devm_kfree(dev, ipmi);

	return rc;

}



static int ipmi_powernv_remove(struct platform_device *pdev)

{

	struct ipmi_smi_powernv *smi = dev_get_drvdata(&pdev->dev);



	ipmi_unregister_smi(smi->intf);

	opal_notifier_unregister(&smi->event_nb);

	return 0;

}



static const struct of_device_id ipmi_powernv_match[] = {

	{ .compatible = "ibm,opal-ipmi" },

	{ },

};





static struct platform_driver powernv_ipmi_driver = {

	.driver = {

		.name		= "ipmi-powernv",

		.owner		= THIS_MODULE,

		.of_match_table	= ipmi_powernv_match,

	},

	.probe	= ipmi_powernv_probe,

	.remove	= ipmi_powernv_remove,

};





module_platform_driver(powernv_ipmi_driver);



MODULE_DEVICE_TABLE(of, ipmi_powernv_match);

MODULE_DESCRIPTION("powernv IPMI driver");

MODULE_AUTHOR("Jeremy Kerr <jk@ozlabs.org>");

MODULE_LICENSE("GPL");