From 28f26ac7a963901106b64307bc1c93068331a008 Mon Sep 17 00:00:00 2001 From: Corey Minyard Date: Fri, 1 Sep 2017 15:30:46 -0500 Subject: ipmi: Dynamically fetch GUID periodically This will catch if the GUID changes. Signed-off-by: Corey Minyard --- drivers/char/ipmi/ipmi_msghandler.c | 61 +++++++++++++++++++++++++------------ 1 file changed, 42 insertions(+), 19 deletions(-) (limited to 'drivers/char') diff --git a/drivers/char/ipmi/ipmi_msghandler.c b/drivers/char/ipmi/ipmi_msghandler.c index 9a6b048b1792..98318b965de7 100644 --- a/drivers/char/ipmi/ipmi_msghandler.c +++ b/drivers/char/ipmi/ipmi_msghandler.c @@ -274,7 +274,8 @@ struct bmc_device { unsigned long dyn_id_expiry; struct mutex dyn_mutex; /* protects id & dyn* fields */ u8 guid[16]; - int guid_set; + u8 fetch_guid[16]; + int dyn_guid_set; struct kref usecount; }; #define to_bmc_device(x) container_of((x), struct bmc_device, pdev.dev) @@ -538,6 +539,8 @@ struct ipmi_smi { }; #define to_si_intf_from_dev(device) container_of(device, struct ipmi_smi, dev) +static void __get_guid(ipmi_smi_t intf); + /** * The driver model view of the IPMI messaging driver. */ @@ -2198,7 +2201,7 @@ static int bmc_get_device_id(ipmi_smi_t intf, struct bmc_device *bmc, bool *guid_set, u8 *guid) { int rv = 0; - int prev_dyn_id_set; + int prev_dyn_id_set, prev_guid_set; if (!intf) { mutex_lock(&bmc->dyn_mutex); @@ -2230,8 +2233,19 @@ retry_bmc_lock: if (bmc->dyn_id_set && time_is_after_jiffies(bmc->dyn_id_expiry)) goto out; - prev_dyn_id_set = bmc->dyn_id_set; + prev_guid_set = bmc->dyn_guid_set; + __get_guid(intf); + + if (bmc->dyn_guid_set) + memcpy(bmc->guid, bmc->fetch_guid, 16); + else if (prev_guid_set) + /* + * The guid used to be valid and it failed to fetch, + * just use the cached value. + */ + bmc->dyn_guid_set = prev_guid_set; + prev_dyn_id_set = bmc->dyn_id_set; rv = __get_device_id(intf, bmc); if (rv) goto out; @@ -2250,9 +2264,9 @@ out: *id = bmc->id; if (guid_set) - *guid_set = bmc->guid_set; + *guid_set = bmc->dyn_guid_set; - if (guid && bmc->guid_set) + if (guid && bmc->dyn_guid_set) memcpy(guid, bmc->guid, 16); mutex_unlock(&bmc->dyn_mutex); @@ -2845,7 +2859,7 @@ static int ipmi_bmc_register(ipmi_smi_t intf, int ifnum) * representing the interfaced BMC already */ mutex_lock(&ipmidriver_mutex); - if (bmc->guid_set) + if (bmc->dyn_guid_set) old_bmc = ipmi_find_bmc_guid(&ipmidriver.driver, bmc->guid); else old_bmc = ipmi_find_bmc_prod_dev_id(&ipmidriver.driver, @@ -2997,9 +3011,10 @@ send_guid_cmd(ipmi_smi_t intf, int chan) -1, 0); } -static void -guid_handler(ipmi_smi_t intf, struct ipmi_recv_msg *msg) +static void guid_handler(ipmi_smi_t intf, struct ipmi_recv_msg *msg) { + struct bmc_device *bmc = intf->bmc; + if ((msg->addr.addr_type != IPMI_SYSTEM_INTERFACE_ADDR_TYPE) || (msg->msg.netfn != IPMI_NETFN_APP_RESPONSE) || (msg->msg.cmd != IPMI_GET_DEVICE_GUID_CMD)) @@ -3008,12 +3023,12 @@ guid_handler(ipmi_smi_t intf, struct ipmi_recv_msg *msg) if (msg->msg.data[0] != 0) { /* Error from getting the GUID, the BMC doesn't have one. */ - intf->bmc->guid_set = 0; + bmc->dyn_guid_set = 0; goto out; } if (msg->msg.data_len < 17) { - intf->bmc->guid_set = 0; + bmc->dyn_guid_set = 0; printk(KERN_WARNING PFX "guid_handler: The GUID response from the BMC was too" " short, it was %d but should have been 17. Assuming" @@ -3022,24 +3037,34 @@ guid_handler(ipmi_smi_t intf, struct ipmi_recv_msg *msg) goto out; } - memcpy(intf->bmc->guid, msg->msg.data + 1, 16); - intf->bmc->guid_set = 1; + memcpy(bmc->fetch_guid, msg->msg.data + 1, 16); + /* + * Make sure the guid data is available before setting + * dyn_guid_set. + */ + smp_wmb(); + bmc->dyn_guid_set = 1; out: wake_up(&intf->waitq); } -static void -get_guid(ipmi_smi_t intf) +static void __get_guid(ipmi_smi_t intf) { int rv; + struct bmc_device *bmc = intf->bmc; - intf->bmc->guid_set = 0x2; + bmc->dyn_guid_set = 2; intf->null_user_handler = guid_handler; rv = send_guid_cmd(intf, 0); if (rv) /* Send failed, no GUID available. */ - intf->bmc->guid_set = 0; - wait_event(intf->waitq, intf->bmc->guid_set != 2); + bmc->dyn_guid_set = 0; + + wait_event(intf->waitq, bmc->dyn_guid_set != 2); + + /* dyn_guid_set makes the guid data available. */ + smp_rmb(); + intf->null_user_handler = NULL; } @@ -3254,8 +3279,6 @@ int ipmi_register_smi(const struct ipmi_smi_handlers *handlers, if (rv) goto out; - get_guid(intf); - rv = bmc_get_device_id(intf, NULL, &id, NULL, NULL); if (rv) { dev_err(si_dev, "Unable to get the device id: %d\n", rv); -- cgit v1.2.3