Re: [PATCH v4 2/2] IPMI/ACPI: Install the IPMI space handler to enable ACPI to access the BMC controller

[ykzhao <yakui.zhao@intel.com>]

On Fri, 2009-12-18 at 15:57 +0800, Zhao, Yakui wrote:
> From: Zhao Yakui <yakui.zhao@intel.com>
> 
> 
Hi, Bjorn
     Do you have an opportunity to look at the updated patch?
     Any comment about this patch set?
     If it is ok to you, can you add the "review-by"?

thanks.
    Yakui
> ACPI 4.0 spec adds the ACPI IPMI opregion, which means that the ACPI AML
> code can also communicate with the BMC controller. This is to install
> the ACPI IPMI opregion and enable the ACPI to access the BMC controller
> through the IPMI message.
> 
>      It will create IPMI user interface for every IPMI device detected
> in ACPI namespace and install the corresponding IPMI opregion space handler.
> Then it can enable ACPI to access the BMC controller through the IPMI
> message.
> 
> The following describes how to process the IPMI request in IPMI space handler:
>     1. format the IPMI message based on the request in AML code.
>     IPMI system address. Now the address type is SYSTEM_INTERFACE_ADDR_TYPE
>     IPMI net function & command
>     IPMI message payload
>     2. send the IPMI message by using the function of ipmi_request_settime
>     3. wait for the completion of IPMI message. It can be done in different
> routes: One is in handled in IPMI user recv callback function. Another is
> handled in timeout function.
>     4. format the IPMI response and return it to ACPI AML code.
> 
> Signed-off-by: Zhao Yakui <yakui.zhao@intel.com>
> cc: Bjorn Helgaas <bjorn.helgaas@hp.com>
> ---
>  drivers/char/ipmi/ipmi_si_intf.c |  494 +++++++++++++++++++++++++++++++++++++-
>  1 files changed, 490 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/char/ipmi/ipmi_si_intf.c b/drivers/char/ipmi/ipmi_si_intf.c
> index 99fecd2..e52629f 100644
> --- a/drivers/char/ipmi/ipmi_si_intf.c
> +++ b/drivers/char/ipmi/ipmi_si_intf.c
> @@ -65,7 +65,7 @@
>  #include <linux/string.h>
>  #include <linux/ctype.h>
>  #include <linux/pnp.h>
> -
> +#include <linux/ipmi.h>
>  #ifdef CONFIG_PPC_OF
>  #include <linux/of_device.h>
>  #include <linux/of_platform.h>
> @@ -1808,6 +1808,463 @@ static __devinit void hardcode_find_bmc(void)
> 
>  #include <linux/acpi.h>
> 
> +#define IPMI_FLAGS_HANDLER_INSTALL     0
> +#define ACPI_IPMI_OK                   0
> +#define ACPI_IPMI_TIMEOUT              0x10
> +#define ACPI_IPMI_UNKNOWN              0x07
> +/* the IPMI timeout is 30s */
> +#define IPMI_TIMEOUT                   (30 * HZ)
> +
> +struct acpi_ipmi_device {
> +       acpi_handle handle;
> +       struct acpi_device *device;
> +       /* the device list attached to driver_data.ipmi_devices */
> +       struct list_head head;
> +       ipmi_user_t     user_interface;
> +       struct mutex    mutex_lock;
> +       /* the IPMI request message list */
> +       struct list_head tx_msg_list;
> +       long curr_msgid;
> +       /* IPMI flags */
> +       unsigned long flags;
> +       /* IPMI interface number */
> +       int ipmi_ifnum;
> +       struct smi_info *smi_info;
> +};
> +
> +struct ipmi_driver_data {
> +       int device_count;
> +       struct list_head        ipmi_devices;
> +       struct ipmi_smi_watcher bmc_events;
> +       struct ipmi_user_hndl   ipmi_hndlrs;
> +};
> +
> +struct acpi_ipmi_msg {
> +       /* message list */
> +       struct list_head head;
> +       /*
> +        * General speaking the addr type should be SI_ADDR_TYPE. And
> +        * the addr channel should be BMC.
> +        * In fact it can also be IPMB type. But we will have to
> +        * parse it from the Netfn command buffer. It is so complex
> +        * that it is skipped.
> +        */
> +       struct ipmi_addr addr;
> +       /* tx message id */
> +       long tx_msgid;
> +       /* it is used to track whether the IPMI message is finished */
> +       struct completion tx_complete;
> +       struct kernel_ipmi_msg tx_message;
> +       int     msg_done;
> +       /* tx data . And copy it from ACPI object buffer */
> +       u8      tx_data[64];
> +       int     tx_len;
> +       /* get the response data */
> +       u8      rx_data[64];
> +       /* the response length. The netfn & cmd is excluded. */
> +       int     rx_len;
> +       struct acpi_ipmi_device *device;
> +};
> +
> +/*
> + * IPMI request/response buffer.
> + * The length is 66 bytes.
> + */
> +struct acpi_ipmi_buffer {
> +       /* status code of a given IPMI command */
> +       u8 status_code;
> +       /* the length of the payload */
> +       u8 length;
> +       /*
> +        * the payload. Before the operation is carried out, it represents the
> +        * request message payload. After the operation is carried out, it
> +        * stores the response message returned by IPMI command.
> +        */
> +       u8 data[64];
> +};
> +
> +
> +static void ipmi_register_bmc(int iface, struct device *dev);
> +static void ipmi_bmc_gone(int iface);
> +static void ipmi_msg_handler(struct ipmi_recv_msg *msg, void *user_msg_data);
> +
> +static struct ipmi_driver_data driver_data = {
> +       .ipmi_devices = LIST_HEAD_INIT(driver_data.ipmi_devices),
> +       .bmc_events = {
> +               .owner = THIS_MODULE,
> +               .new_smi = ipmi_register_bmc,
> +               .smi_gone = ipmi_bmc_gone,
> +       },
> +       .ipmi_hndlrs = {
> +               .ipmi_recv_hndl = ipmi_msg_handler,
> +       },
> +};
> +
> +static
> +struct acpi_ipmi_msg *acpi_alloc_ipmi_msg(struct acpi_ipmi_device *ipmi)
> +{
> +       struct acpi_ipmi_msg *ipmi_msg;
> +
> +       ipmi_msg = kzalloc(sizeof(struct acpi_ipmi_msg), GFP_KERNEL);
> +       if (!ipmi_msg)  {
> +               printk(KERN_DEBUG "Can't allocate memory for ipmi_msg\n");
> +               return NULL;
> +       }
> +       init_completion(&ipmi_msg->tx_complete);
> +       INIT_LIST_HEAD(&ipmi_msg->head);
> +       ipmi_msg->device = ipmi;
> +       return ipmi_msg;
> +}
> +
> +static void acpi_format_ipmi_msg(struct acpi_ipmi_msg *tx_msg,
> +               acpi_physical_address address,
> +               acpi_integer *value)
> +{
> +       struct kernel_ipmi_msg *msg;
> +       u8      temp_value;
> +       struct acpi_ipmi_buffer *buffer;
> +       struct acpi_ipmi_device *device;
> +
> +       msg = &tx_msg->tx_message;
> +       /* get the netfn */
> +       temp_value = (address >> 8) & 0xff;
> +       msg->netfn = temp_value;
> +       /* get the command */
> +       temp_value = address & 0xff;
> +       msg->cmd = temp_value;
> +       msg->data = tx_msg->tx_data;
> +       /*
> +        * value is the parameter passed by the IPMI opregion space handler.
> +        * It points to the IPMI request message buffer
> +        */
> +       buffer = (struct acpi_ipmi_buffer *)value;
> +       /* copy the tx message data */
> +       msg->data_len = buffer->length;
> +       memcpy(tx_msg->tx_data, buffer->data, msg->data_len);
> +       /*
> +        * now the default type is SYSTEM_INTERFACE and channel type is BMC.
> +        * If the netfn is APP_REQUEST and the cmd is SEND_MESSAGE,
> +        * the addr type should be changed to IPMB.
> +        */
> +       tx_msg->addr.addr_type = IPMI_SYSTEM_INTERFACE_ADDR_TYPE;
> +       tx_msg->addr.channel = IPMI_BMC_CHANNEL;
> +       tx_msg->addr.data[0] = 0;
> +
> +       /*
> +        * If the netfn is APP_REQUEST and the cmd is SEND_MESSAGE, we should
> +        * parse the IPMI request message buffer to get the IPMB address.
> +        * If so, please fix me.
> +        */
> +
> +       /* Get the msgid */
> +       device = tx_msg->device;
> +       mutex_lock(&device->mutex_lock);
> +       device->curr_msgid++;
> +       tx_msg->tx_msgid = device->curr_msgid;
> +       mutex_unlock(&device->mutex_lock);
> +}
> +
> +static void acpi_format_ipmi_response(struct acpi_ipmi_msg *msg,
> +               acpi_integer *value, int timeout)
> +{
> +       struct acpi_ipmi_buffer *buffer;
> +
> +       /*
> +        * value is also used as output parameter. It represents the response
> +        * IPMI message returned by IPMI command.
> +        */
> +       buffer = (struct acpi_ipmi_buffer *)value;
> +       /* when timeout is zero, it means that the timeout happens */
> +       if (!timeout) {
> +               /* the status code is ACPI_IPMI_TIMEOUT */
> +               buffer->status_code = ACPI_IPMI_TIMEOUT;
> +               return;
> +       }
> +       /*
> +        * If the flag of msg_done is not set, it means that the IPMI command
> +        * is not executed correctly.
> +        * The status code will be ACPI_IPMI_UNKNOWN.
> +        */
> +       if (!msg->msg_done) {
> +               buffer->status_code = ACPI_IPMI_UNKNOWN;
> +               return;
> +       }
> +       /*
> +        * If the IPMI response message is obtained correctly, the status code
> +        * will be ACPI_IPMI_OK
> +        */
> +       buffer->status_code = ACPI_IPMI_OK;
> +       buffer->length = msg->rx_len;
> +       memcpy(buffer->data, msg->rx_data, msg->rx_len);
> +}
> +
> +static void ipmi_destroy_tx_msg(struct acpi_ipmi_device *ipmi)
> +{
> +       struct acpi_ipmi_msg *tx_msg = NULL, *temp;
> +       int count = 20;
> +
> +       list_for_each_entry_safe(tx_msg, temp, &ipmi->tx_msg_list, head) {
> +               /* wake up the sleep thread on the Tx msg */
> +               complete(&tx_msg->tx_complete);
> +       }
> +       /* wait for about 20 ticks to flush the tx message list */
> +       while (count--) {
> +               if (list_empty(&ipmi->tx_msg_list))
> +                       break;
> +               schedule_timeout(1);
> +       }
> +       if (!list_empty(&ipmi->tx_msg_list))
> +               printk(KERN_DEBUG "tx msg list is not NULL\n");
> +
> +}
> +
> +static void ipmi_msg_handler(struct ipmi_recv_msg *msg, void *user_msg_data)
> +{
> +       struct acpi_ipmi_device *ipmi_device = user_msg_data;
> +       int msg_found = 0;
> +       struct acpi_ipmi_msg *tx_msg;
> +
> +       if (msg->user != ipmi_device->user_interface) {
> +               printk(KERN_DEBUG "Incorrect IPMI user\n");
> +               ipmi_free_recv_msg(msg);
> +               return;
> +       }
> +       mutex_lock(&ipmi_device->mutex_lock);
> +       list_for_each_entry(tx_msg, &ipmi_device->tx_msg_list, head) {
> +               if (msg->msgid == tx_msg->tx_msgid) {
> +                       /* find the message id */
> +                       msg_found = 1;
> +                       break;
> +               }
> +       }
> +
> +       mutex_unlock(&ipmi_device->mutex_lock);
> +       if (!msg_found) {
> +               /* no matched msg is found . But we should free it */
> +               ipmi_free_recv_msg(msg);
> +               printk(KERN_DEBUG "Incorrect MSG is found \n");
> +               return;
> +       }
> +
> +       if (msg->msg.data_len > 1) {
> +               /* copy the response data to Rx_data buffer */
> +               memcpy(tx_msg->rx_data, msg->msg_data, msg->msg.data_len);
> +               tx_msg->rx_len = msg->msg.data_len;
> +               tx_msg->msg_done = 1;
> +       }
> +       complete(&tx_msg->tx_complete);
> +       ipmi_free_recv_msg(msg);
> +};
> +
> +static void ipmi_register_bmc(int iface, struct device *dev)
> +{
> +       struct acpi_ipmi_device *ipmi_device, *temp;
> +       struct acpi_device *device;
> +       ipmi_user_t             user;
> +       int err;
> +
> +       if (list_empty(&driver_data.ipmi_devices))
> +               return;
> +
> +       list_for_each_entry_safe(ipmi_device, temp,
> +                                       &driver_data.ipmi_devices, head) {
> +               device = ipmi_device->device;
> +               if (ipmi_device->user_interface) {
> +                       /*
> +                        * Only one user interface is allowed to be registered
> +                        * for one IPMI device.
> +                        * If we already create the user interface for
> +                        * one IPMI device, skip it
> +                        */
> +                       continue;
> +               }
> +               if (dev == &device->dev) {
> +                       /*
> +                        * If the dev is identical to the ACPI device,
> +                        * create the user interface.
> +                        */
> +                       err = ipmi_create_user(iface, &driver_data.ipmi_hndlrs,
> +                                               ipmi_device, &user);
> +                       if (err == 0) {
> +                               ipmi_device->user_interface = user;
> +                               ipmi_device->ipmi_ifnum = iface;
> +                       }
> +               }
> +       }
> +}
> +
> +static void ipmi_bmc_gone(int iface)
> +{
> +       struct acpi_ipmi_device *ipmi_device, *temp;
> +
> +       if (list_empty(&driver_data.ipmi_devices))
> +               return;
> +
> +       list_for_each_entry_safe(ipmi_device, temp,
> +                               &driver_data.ipmi_devices, head) {
> +               if (ipmi_device->user_interface &&
> +                               (ipmi_device->ipmi_ifnum == iface)) {
> +                       ipmi_destroy_user(ipmi_device->user_interface);
> +                       ipmi_device->user_interface = NULL;
> +                       ipmi_destroy_tx_msg(ipmi_device);
> +               }
> +       }
> +}
> +/* --------------------------------------------------------------------------
> + *                     Address Space Management
> +   -------------------------------------------------------------------------- */
> +/*
> + * This is the IPMI opregion space handler.
> + * @function: indicates the read/write. In fact as the IPMI message is driven
> + * by command, only write is meaningful.
> + * @address: This contains the netfn/command of IPMI request message.
> + * @bits   : not used.
> + * @value  : it is an in/out parameter. It points to the IPMI message buffer.
> + *          Before the IPMI message is sent, it represents the actual request
> + *          IPMI message. After the IPMI message is finished, it represents
> + *          the response IPMI message returned by IPMI command.
> + * @handler_context: IPMI device context.
> + */
> +
> +static acpi_status
> +acpi_ipmi_space_handler(u32 function, acpi_physical_address address,
> +                     u32 bits, acpi_integer *value,
> +                     void *handler_context, void *region_context)
> +{
> +       struct acpi_ipmi_msg *tx_msg = NULL;
> +       struct acpi_ipmi_device *ipmi_device =
> +                       (struct acpi_ipmi_device *) handler_context;
> +       int err;
> +       acpi_status status;
> +       /*
> +        * IPMI opregion message.
> +        * IPMI message is firstly written to the BMC and system software
> +        * can get the respsonse. So it is unmeaningful for the IPMI read
> +        * access.
> +        */
> +       if ((function & ACPI_IO_MASK) == ACPI_READ) {
> +               /* Read function is not supported. AE_TYPE is returned. */
> +               return AE_TYPE;
> +       }
> +       if (!ipmi_device->user_interface)
> +               return AE_NOT_EXIST;
> +
> +       tx_msg = acpi_alloc_ipmi_msg(ipmi_device);
> +       if (!tx_msg)
> +               return AE_NO_MEMORY;
> +
> +       acpi_format_ipmi_msg(tx_msg, address, value);
> +       mutex_lock(&ipmi_device->mutex_lock);
> +       list_add_tail(&tx_msg->head, &ipmi_device->tx_msg_list);
> +       mutex_unlock(&ipmi_device->mutex_lock);
> +       err = ipmi_request_settime(ipmi_device->user_interface,
> +                                       &tx_msg->addr,
> +                                       tx_msg->tx_msgid,
> +                                       &tx_msg->tx_message,
> +                                       NULL, 0, 0, 0);
> +       if (err) {
> +               status = AE_ERROR;
> +               goto end_label;
> +       }
> +       err = wait_for_completion_timeout(&tx_msg->tx_complete, IPMI_TIMEOUT);
> +
> +       acpi_format_ipmi_response(tx_msg, value, err);
> +       status = AE_OK;
> +
> +end_label:
> +       mutex_lock(&ipmi_device->mutex_lock);
> +       list_del(&tx_msg->head);
> +       mutex_unlock(&ipmi_device->mutex_lock);
> +       kfree(tx_msg);
> +       return status;
> +}
> +
> +static void ipmi_remove_handler(struct acpi_ipmi_device *ipmi)
> +{
> +       if (!test_bit(IPMI_FLAGS_HANDLER_INSTALL, &ipmi->flags))
> +               return;
> +
> +       acpi_remove_address_space_handler(ipmi->handle,
> +                               ACPI_ADR_SPACE_IPMI, &acpi_ipmi_space_handler);
> +
> +       clear_bit(IPMI_FLAGS_HANDLER_INSTALL, &ipmi->flags);
> +}
> +
> +static int ipmi_install_handler(struct acpi_ipmi_device *ipmi)
> +{
> +       acpi_status status;
> +
> +       if (test_bit(IPMI_FLAGS_HANDLER_INSTALL, &ipmi->flags))
> +               return 0;
> +
> +       status = acpi_install_address_space_handler(ipmi->handle,
> +                                                   ACPI_ADR_SPACE_IPMI,
> +                                                   &acpi_ipmi_space_handler,
> +                                                   NULL, ipmi);
> +       if (ACPI_FAILURE(status)) {
> +               printk(KERN_DEBUG "Can't register IPMI opregion %s\n",
> +                                       acpi_device_bid(ipmi->device));
> +               return -EINVAL;
> +       }
> +
> +       test_bit(IPMI_FLAGS_HANDLER_INSTALL, &ipmi->flags);
> +
> +       return 0;
> +}
> +
> +static void acpi_register_ipmi_handler(struct acpi_ipmi_device *ipmi_device)
> +{
> +       if (list_empty(&driver_data.ipmi_devices)) {
> +               /*
> +                * when we try to register the first IPI0001 device, register
> +                * the smi_watcher.
> +                */
> +               ipmi_smi_watcher_register(&driver_data.bmc_events);
> +       }
> +
> +       mutex_init(&ipmi_device->mutex_lock);
> +       INIT_LIST_HEAD(&ipmi_device->tx_msg_list);
> +
> +       if (ipmi_install_handler(ipmi_device)) {
> +               /*
> +                * can't register the IPMI opregion. We will print
> +                * some debug info and continue to register ipmi
> +                * opregion for next device.
> +                */
> +               printk(KERN_DEBUG "Can't register IPMI opregion %s\n",
> +                               acpi_device_bid(ipmi_device->device));
> +       }
> +       list_add(&ipmi_device->head, &driver_data.ipmi_devices);
> +}
> +
> +static void acpi_remove_ipmi_handler(struct acpi_ipmi_device *ipmi_device)
> +{
> +       if (!ipmi_device)
> +               return;
> +
> +       if (ipmi_device->user_interface) {
> +               /*
> +                * If the IPMI user interface is created, it
> +                * should be destroyed.
> +                */
> +               ipmi_destroy_user(ipmi_device->user_interface);
> +               ipmi_device->user_interface = NULL;
> +       }
> +       list_del(&ipmi_device->head);
> +
> +       if (!list_empty(&ipmi_device->tx_msg_list))
> +               ipmi_destroy_tx_msg(ipmi_device);
> +
> +       ipmi_remove_handler(ipmi_device);
> +       if (list_empty(&driver_data.ipmi_devices)) {
> +               /*
> +                * when no IPI0001 device is in the list, uninstall the
> +                * smi_watcher.
> +                */
> +               ipmi_smi_watcher_unregister(&driver_data.bmc_events);
> +       }
> +}
> +
>  /*
>   * Once we get an ACPI failure, we don't try any more, because we go
>   * through the tables sequentially.  Once we don't find a table, there
> @@ -2033,6 +2490,8 @@ static int __devinit ipmi_pnp_probe(struct pnp_dev *dev,
>         acpi_handle handle;
>         acpi_status status;
>         unsigned long long tmp;
> +       int ret;
> +       struct acpi_ipmi_device *p_ipmi;
> 
>         acpi_dev = pnp_acpi_device(dev);
>         if (!acpi_dev)
> @@ -2042,6 +2501,13 @@ static int __devinit ipmi_pnp_probe(struct pnp_dev *dev,
>         if (!info)
>                 return -ENOMEM;
> 
> +       p_ipmi = kzalloc(sizeof(*p_ipmi), GFP_KERNEL);
> +       if (!p_ipmi) {
> +               printk(KERN_ERR "Can't allocate memory for IPMI device\n");
> +               kfree(info);
> +               return -ENOMEM;
> +       }
> +
>         info->addr_source = "ACPI";
> 
>         handle = acpi_dev->handle;
> @@ -2094,20 +2560,39 @@ static int __devinit ipmi_pnp_probe(struct pnp_dev *dev,
>         }
> 
>         info->dev = &acpi_dev->dev;
> -       pnp_set_drvdata(dev, info);
> +       p_ipmi->smi_info = info;
> +       pnp_set_drvdata(dev, p_ipmi);
> 
> -       return try_smi_init(info);
> +       p_ipmi->device = acpi_dev;
> +       p_ipmi->handle = handle;
> +       p_ipmi->ipmi_ifnum = -1;
> +       acpi_register_ipmi_handler(p_ipmi);
> +
> +       ret = try_smi_init(info);
> +       if (!ret)
> +               return ret;
> +       else
> +               acpi_remove_ipmi_handler(p_ipmi);
> 
>  err_free:
> +       pnp_set_drvdata(dev, NULL);
> +       kfree(p_ipmi);
>         kfree(info);
>         return -EINVAL;
>  }
> 
>  static void __devexit ipmi_pnp_remove(struct pnp_dev *dev)
>  {
> -       struct smi_info *info = pnp_get_drvdata(dev);
> +       struct acpi_ipmi_device *p_ipmi;
> +       struct smi_info *info;
> +
> +       p_ipmi = pnp_get_drvdata(dev);
> +       info = p_ipmi->smi_info;
> 
>         cleanup_one_si(info);
> +       acpi_remove_ipmi_handler(p_ipmi);
> +       pnp_set_drvdata(dev, NULL);
> +       kfree(p_ipmi);
>  }
> 
>  static const struct pnp_device_id pnp_dev_table[] = {
> @@ -3331,6 +3816,7 @@ static __exit void cleanup_ipmi_si(void)
>  #ifdef CONFIG_PCI
>         pci_unregister_driver(&ipmi_pci_driver);
>  #endif
> +
>  #ifdef CONFIG_PNP
>         pnp_unregister_driver(&ipmi_pnp_driver);
>  #endif
> --
> 1.5.4.5
> 


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