Add support for IPMB driver
Support receiving IPMB requests on a Satellite MC from the BMC. Once a response is ready, this driver will send back a response to the BMC via the IPMB channel. Signed-off-by: Asmaa Mnebhi <Asmaa@mellanox.com> Acked-by: vadimp@mellanox.com Message-Id: <319690553a0da2a1e80b400941341081b383e5f1.1560192707.git.Asmaa@mellanox.com> [Move the config option to outside the ipmi msghandler, as it's not dependent on that. Fixed one small whitespace issue.] Signed-off-by: Corey Minyard <cminyard@mvista.com>alistair/sunxi64-5.4-dsi
Asmaa Mnebhi
Corey Minyard
parent
3559c3270a
commit
51bd6f2915
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@ -0,0 +1,103 @@
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==============================
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IPMB Driver for a Satellite MC
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==============================
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The Intelligent Platform Management Bus or IPMB, is an
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I2C bus that provides a standardized interconnection between
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different boards within a chassis. This interconnection is
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between the baseboard management (BMC) and chassis electronics.
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IPMB is also associated with the messaging protocol through the
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IPMB bus.
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The devices using the IPMB are usually management
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controllers that perform management functions such as servicing
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the front panel interface, monitoring the baseboard,
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hot-swapping disk drivers in the system chassis, etc...
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When an IPMB is implemented in the system, the BMC serves as
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a controller to give system software access to the IPMB. The BMC
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sends IPMI requests to a device (usually a Satellite Management
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Controller or Satellite MC) via IPMB and the device
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sends a response back to the BMC.
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For more information on IPMB and the format of an IPMB message,
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refer to the IPMB and IPMI specifications.
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IPMB driver for Satellite MC
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----------------------------
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ipmb-dev-int - This is the driver needed on a Satellite MC to
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receive IPMB messages from a BMC and send a response back.
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This driver works with the I2C driver and a userspace
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program such as OpenIPMI:
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1) It is an I2C slave backend driver. So, it defines a callback
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function to set the Satellite MC as an I2C slave.
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This callback function handles the received IPMI requests.
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2) It defines the read and write functions to enable a user
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space program (such as OpenIPMI) to communicate with the kernel.
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Load the IPMB driver
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--------------------
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The driver needs to be loaded at boot time or manually first.
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First, make sure you have the following in your config file:
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CONFIG_IPMB_DEVICE_INTERFACE=y
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1) If you want the driver to be loaded at boot time:
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a) Add this entry to your ACPI table, under the appropriate SMBus:
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Device (SMB0) // Example SMBus host controller
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{
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Name (_HID, "<Vendor-Specific HID>") // Vendor-Specific HID
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Name (_UID, 0) // Unique ID of particular host controller
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:
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:
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Device (IPMB)
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{
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Name (_HID, "IPMB0001") // IPMB device interface
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Name (_UID, 0) // Unique device identifier
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}
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}
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b) Example for device tree:
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&i2c2 {
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status = "okay";
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ipmb@10 {
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compatible = "ipmb-dev";
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reg = <0x10>;
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};
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};
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2) Manually from Linux:
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modprobe ipmb-dev-int
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Instantiate the device
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----------------------
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After loading the driver, you can instantiate the device as
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described in 'Documentation/i2c/instantiating-devices'.
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If you have multiple BMCs, each connected to your Satellite MC via
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a different I2C bus, you can instantiate a device for each of
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those BMCs.
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The name of the instantiated device contains the I2C bus number
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associated with it as follows:
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BMC1 ------ IPMB/I2C bus 1 ---------| /dev/ipmb-1
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Satellite MC
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BMC1 ------ IPMB/I2C bus 2 ---------| /dev/ipmb-2
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For instance, you can instantiate the ipmb-dev-int device from
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user space at the 7 bit address 0x10 on bus 2:
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# echo ipmb-dev 0x1010 > /sys/bus/i2c/devices/i2c-2/new_device
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This will create the device file /dev/ipmb-2, which can be accessed
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by the user space program. The device needs to be instantiated
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before running the user space program.
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@ -131,3 +131,11 @@ config ASPEED_BT_IPMI_BMC
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Provides a driver for the BT (Block Transfer) IPMI interface
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found on Aspeed SOCs (AST2400 and AST2500). The driver
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implements the BMC side of the BT interface.
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config IPMB_DEVICE_INTERFACE
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tristate 'IPMB Interface handler'
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depends on I2C_SLAVE
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help
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Provides a driver for a device (Satellite MC) to
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receive requests and send responses back to the BMC via
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the IPMB interface. This module requires I2C support.
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@ -26,3 +26,4 @@ obj-$(CONFIG_IPMI_KCS_BMC) += kcs_bmc.o
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obj-$(CONFIG_ASPEED_BT_IPMI_BMC) += bt-bmc.o
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obj-$(CONFIG_ASPEED_KCS_IPMI_BMC) += kcs_bmc_aspeed.o
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obj-$(CONFIG_NPCM7XX_KCS_IPMI_BMC) += kcs_bmc_npcm7xx.o
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obj-$(CONFIG_IPMB_DEVICE_INTERFACE) += ipmb_dev_int.o
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@ -0,0 +1,364 @@
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// SPDX-License-Identifier: GPL-2.0
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/*
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* IPMB driver to receive a request and send a response
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*
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* Copyright (C) 2019 Mellanox Techologies, Ltd.
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*
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* This was inspired by Brendan Higgins' ipmi-bmc-bt-i2c driver.
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*/
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#include <linux/acpi.h>
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#include <linux/errno.h>
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#include <linux/i2c.h>
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#include <linux/miscdevice.h>
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#include <linux/module.h>
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#include <linux/mutex.h>
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#include <linux/poll.h>
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#include <linux/slab.h>
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#include <linux/spinlock.h>
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#include <linux/wait.h>
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#define MAX_MSG_LEN 128
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#define IPMB_REQUEST_LEN_MIN 7
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#define NETFN_RSP_BIT_MASK 0x4
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#define REQUEST_QUEUE_MAX_LEN 256
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#define IPMB_MSG_LEN_IDX 0
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#define RQ_SA_8BIT_IDX 1
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#define NETFN_LUN_IDX 2
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#define GET_7BIT_ADDR(addr_8bit) (addr_8bit >> 1)
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#define GET_8BIT_ADDR(addr_7bit) ((addr_7bit << 1) & 0xff)
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#define IPMB_MSG_PAYLOAD_LEN_MAX (MAX_MSG_LEN - IPMB_REQUEST_LEN_MIN - 1)
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#define SMBUS_MSG_HEADER_LENGTH 2
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#define SMBUS_MSG_IDX_OFFSET (SMBUS_MSG_HEADER_LENGTH + 1)
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struct ipmb_msg {
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u8 len;
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u8 rs_sa;
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u8 netfn_rs_lun;
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u8 checksum1;
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u8 rq_sa;
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u8 rq_seq_rq_lun;
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u8 cmd;
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u8 payload[IPMB_MSG_PAYLOAD_LEN_MAX];
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/* checksum2 is included in payload */
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} __packed;
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struct ipmb_request_elem {
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struct list_head list;
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struct ipmb_msg request;
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};
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struct ipmb_dev {
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struct i2c_client *client;
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struct miscdevice miscdev;
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struct ipmb_msg request;
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struct list_head request_queue;
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atomic_t request_queue_len;
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size_t msg_idx;
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spinlock_t lock;
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wait_queue_head_t wait_queue;
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struct mutex file_mutex;
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};
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static inline struct ipmb_dev *to_ipmb_dev(struct file *file)
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{
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return container_of(file->private_data, struct ipmb_dev, miscdev);
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}
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static ssize_t ipmb_read(struct file *file, char __user *buf, size_t count,
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loff_t *ppos)
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{
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struct ipmb_dev *ipmb_dev = to_ipmb_dev(file);
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struct ipmb_request_elem *queue_elem;
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struct ipmb_msg msg;
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ssize_t ret;
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memset(&msg, 0, sizeof(msg));
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spin_lock_irq(&ipmb_dev->lock);
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while (list_empty(&ipmb_dev->request_queue)) {
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spin_unlock_irq(&ipmb_dev->lock);
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if (file->f_flags & O_NONBLOCK)
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return -EAGAIN;
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ret = wait_event_interruptible(ipmb_dev->wait_queue,
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!list_empty(&ipmb_dev->request_queue));
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if (ret)
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return ret;
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spin_lock_irq(&ipmb_dev->lock);
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}
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queue_elem = list_first_entry(&ipmb_dev->request_queue,
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struct ipmb_request_elem, list);
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memcpy(&msg, &queue_elem->request, sizeof(msg));
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list_del(&queue_elem->list);
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kfree(queue_elem);
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atomic_dec(&ipmb_dev->request_queue_len);
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spin_unlock_irq(&ipmb_dev->lock);
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count = min_t(size_t, count, msg.len + 1);
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if (copy_to_user(buf, &msg, count))
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ret = -EFAULT;
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return ret < 0 ? ret : count;
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}
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static ssize_t ipmb_write(struct file *file, const char __user *buf,
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size_t count, loff_t *ppos)
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{
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struct ipmb_dev *ipmb_dev = to_ipmb_dev(file);
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u8 rq_sa, netf_rq_lun, msg_len;
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struct i2c_client rq_client;
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u8 msg[MAX_MSG_LEN];
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ssize_t ret;
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if (count > sizeof(msg))
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return -EINVAL;
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if (copy_from_user(&msg, buf, count))
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return -EFAULT;
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if (count < msg[0])
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return -EINVAL;
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rq_sa = GET_7BIT_ADDR(msg[RQ_SA_8BIT_IDX]);
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netf_rq_lun = msg[NETFN_LUN_IDX];
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if (!(netf_rq_lun & NETFN_RSP_BIT_MASK))
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return -EINVAL;
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/*
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* subtract rq_sa and netf_rq_lun from the length of the msg passed to
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* i2c_smbus_write_block_data_local
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*/
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msg_len = msg[IPMB_MSG_LEN_IDX] - SMBUS_MSG_HEADER_LENGTH;
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strcpy(rq_client.name, "ipmb_requester");
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rq_client.adapter = ipmb_dev->client->adapter;
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rq_client.flags = ipmb_dev->client->flags;
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rq_client.addr = rq_sa;
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ret = i2c_smbus_write_block_data(&rq_client, netf_rq_lun, msg_len,
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msg + SMBUS_MSG_IDX_OFFSET);
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return ret ? : count;
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}
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static unsigned int ipmb_poll(struct file *file, poll_table *wait)
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{
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struct ipmb_dev *ipmb_dev = to_ipmb_dev(file);
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unsigned int mask = POLLOUT;
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mutex_lock(&ipmb_dev->file_mutex);
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poll_wait(file, &ipmb_dev->wait_queue, wait);
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if (atomic_read(&ipmb_dev->request_queue_len))
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mask |= POLLIN;
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mutex_unlock(&ipmb_dev->file_mutex);
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return mask;
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}
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static const struct file_operations ipmb_fops = {
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.owner = THIS_MODULE,
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.read = ipmb_read,
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.write = ipmb_write,
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.poll = ipmb_poll,
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};
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/* Called with ipmb_dev->lock held. */
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static void ipmb_handle_request(struct ipmb_dev *ipmb_dev)
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{
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struct ipmb_request_elem *queue_elem;
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if (atomic_read(&ipmb_dev->request_queue_len) >=
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REQUEST_QUEUE_MAX_LEN)
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return;
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queue_elem = kmalloc(sizeof(*queue_elem), GFP_ATOMIC);
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if (!queue_elem)
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return;
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memcpy(&queue_elem->request, &ipmb_dev->request,
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sizeof(struct ipmb_msg));
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list_add(&queue_elem->list, &ipmb_dev->request_queue);
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atomic_inc(&ipmb_dev->request_queue_len);
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wake_up_all(&ipmb_dev->wait_queue);
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}
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static u8 ipmb_verify_checksum1(struct ipmb_dev *ipmb_dev, u8 rs_sa)
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{
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/* The 8 lsb of the sum is 0 when the checksum is valid */
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return (rs_sa + ipmb_dev->request.netfn_rs_lun +
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ipmb_dev->request.checksum1);
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}
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static bool is_ipmb_request(struct ipmb_dev *ipmb_dev, u8 rs_sa)
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{
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if (ipmb_dev->msg_idx >= IPMB_REQUEST_LEN_MIN) {
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if (ipmb_verify_checksum1(ipmb_dev, rs_sa))
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return false;
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/*
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* Check whether this is an IPMB request or
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* response.
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* The 6 MSB of netfn_rs_lun are dedicated to the netfn
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* while the remaining bits are dedicated to the lun.
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* If the LSB of the netfn is cleared, it is associated
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* with an IPMB request.
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* If the LSB of the netfn is set, it is associated with
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* an IPMB response.
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*/
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if (!(ipmb_dev->request.netfn_rs_lun & NETFN_RSP_BIT_MASK))
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return true;
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}
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return false;
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}
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/*
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* The IPMB protocol only supports I2C Writes so there is no need
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* to support I2C_SLAVE_READ* events.
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* This i2c callback function only monitors IPMB request messages
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* and adds them in a queue, so that they can be handled by
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* receive_ipmb_request.
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*/
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static int ipmb_slave_cb(struct i2c_client *client,
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enum i2c_slave_event event, u8 *val)
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{
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struct ipmb_dev *ipmb_dev = i2c_get_clientdata(client);
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u8 *buf = (u8 *)&ipmb_dev->request;
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unsigned long flags;
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spin_lock_irqsave(&ipmb_dev->lock, flags);
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switch (event) {
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case I2C_SLAVE_WRITE_REQUESTED:
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memset(&ipmb_dev->request, 0, sizeof(ipmb_dev->request));
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ipmb_dev->msg_idx = 0;
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/*
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* At index 0, ipmb_msg stores the length of msg,
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* skip it for now.
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* The len will be populated once the whole
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* buf is populated.
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*
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* The I2C bus driver's responsibility is to pass the
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* data bytes to the backend driver; it does not
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* forward the i2c slave address.
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* Since the first byte in the IPMB message is the
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* address of the responder, it is the responsibility
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* of the IPMB driver to format the message properly.
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* So this driver prepends the address of the responder
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* to the received i2c data before the request message
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* is handled in userland.
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*/
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buf[++ipmb_dev->msg_idx] = GET_8BIT_ADDR(client->addr);
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break;
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case I2C_SLAVE_WRITE_RECEIVED:
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if (ipmb_dev->msg_idx >= sizeof(struct ipmb_msg))
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break;
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buf[++ipmb_dev->msg_idx] = *val;
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break;
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case I2C_SLAVE_STOP:
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ipmb_dev->request.len = ipmb_dev->msg_idx;
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if (is_ipmb_request(ipmb_dev, GET_8BIT_ADDR(client->addr)))
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ipmb_handle_request(ipmb_dev);
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break;
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default:
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break;
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}
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spin_unlock_irqrestore(&ipmb_dev->lock, flags);
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return 0;
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}
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static int ipmb_probe(struct i2c_client *client,
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const struct i2c_device_id *id)
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{
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struct ipmb_dev *ipmb_dev;
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int ret;
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ipmb_dev = devm_kzalloc(&client->dev, sizeof(*ipmb_dev),
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GFP_KERNEL);
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if (!ipmb_dev)
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return -ENOMEM;
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spin_lock_init(&ipmb_dev->lock);
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init_waitqueue_head(&ipmb_dev->wait_queue);
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atomic_set(&ipmb_dev->request_queue_len, 0);
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INIT_LIST_HEAD(&ipmb_dev->request_queue);
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mutex_init(&ipmb_dev->file_mutex);
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ipmb_dev->miscdev.minor = MISC_DYNAMIC_MINOR;
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ipmb_dev->miscdev.name = devm_kasprintf(&client->dev, GFP_KERNEL,
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"%s%d", "ipmb-",
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client->adapter->nr);
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ipmb_dev->miscdev.fops = &ipmb_fops;
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ipmb_dev->miscdev.parent = &client->dev;
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ret = misc_register(&ipmb_dev->miscdev);
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if (ret)
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return ret;
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ipmb_dev->client = client;
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i2c_set_clientdata(client, ipmb_dev);
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ret = i2c_slave_register(client, ipmb_slave_cb);
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if (ret) {
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misc_deregister(&ipmb_dev->miscdev);
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return ret;
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}
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return 0;
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}
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static int ipmb_remove(struct i2c_client *client)
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{
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struct ipmb_dev *ipmb_dev = i2c_get_clientdata(client);
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i2c_slave_unregister(client);
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misc_deregister(&ipmb_dev->miscdev);
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return 0;
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}
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static const struct i2c_device_id ipmb_id[] = {
|
||||
{ "ipmb-dev", 0 },
|
||||
{},
|
||||
};
|
||||
MODULE_DEVICE_TABLE(i2c, ipmb_id);
|
||||
|
||||
static const struct acpi_device_id acpi_ipmb_id[] = {
|
||||
{ "IPMB0001", 0 },
|
||||
{},
|
||||
};
|
||||
MODULE_DEVICE_TABLE(acpi, acpi_ipmb_id);
|
||||
|
||||
static struct i2c_driver ipmb_driver = {
|
||||
.driver = {
|
||||
.owner = THIS_MODULE,
|
||||
.name = "ipmb-dev",
|
||||
.acpi_match_table = ACPI_PTR(acpi_ipmb_id),
|
||||
},
|
||||
.probe = ipmb_probe,
|
||||
.remove = ipmb_remove,
|
||||
.id_table = ipmb_id,
|
||||
};
|
||||
module_i2c_driver(ipmb_driver);
|
||||
|
||||
MODULE_AUTHOR("Mellanox Technologies");
|
||||
MODULE_DESCRIPTION("IPMB driver");
|
||||
MODULE_LICENSE("GPL v2");
|
||||
Loading…
Reference in New Issue