diff options
Diffstat (limited to 'drivers/char/ipmi/ipmi_ssif.c')
| -rw-r--r-- | drivers/char/ipmi/ipmi_ssif.c | 2162 |
1 files changed, 2162 insertions, 0 deletions
diff --git a/drivers/char/ipmi/ipmi_ssif.c b/drivers/char/ipmi/ipmi_ssif.c new file mode 100644 index 0000000000..df8dd50b4c --- /dev/null +++ b/drivers/char/ipmi/ipmi_ssif.c @@ -0,0 +1,2162 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * ipmi_ssif.c + * + * The interface to the IPMI driver for SMBus access to a SMBus + * compliant device. Called SSIF by the IPMI spec. + * + * Author: Intel Corporation + * Todd Davis <todd.c.davis@intel.com> + * + * Rewritten by Corey Minyard <minyard@acm.org> to support the + * non-blocking I2C interface, add support for multi-part + * transactions, add PEC support, and general clenaup. + * + * Copyright 2003 Intel Corporation + * Copyright 2005 MontaVista Software + */ + +/* + * This file holds the "policy" for the interface to the SSIF state + * machine. It does the configuration, handles timers and interrupts, + * and drives the real SSIF state machine. + */ + +#define pr_fmt(fmt) "ipmi_ssif: " fmt +#define dev_fmt(fmt) "ipmi_ssif: " fmt + +#if defined(MODVERSIONS) +#include <linux/modversions.h> +#endif + +#include <linux/module.h> +#include <linux/moduleparam.h> +#include <linux/sched.h> +#include <linux/seq_file.h> +#include <linux/timer.h> +#include <linux/delay.h> +#include <linux/errno.h> +#include <linux/spinlock.h> +#include <linux/slab.h> +#include <linux/list.h> +#include <linux/i2c.h> +#include <linux/ipmi_smi.h> +#include <linux/init.h> +#include <linux/dmi.h> +#include <linux/kthread.h> +#include <linux/acpi.h> +#include <linux/ctype.h> +#include <linux/time64.h> +#include "ipmi_dmi.h" + +#define DEVICE_NAME "ipmi_ssif" + +#define IPMI_GET_SYSTEM_INTERFACE_CAPABILITIES_CMD 0x57 + +#define SSIF_IPMI_REQUEST 2 +#define SSIF_IPMI_MULTI_PART_REQUEST_START 6 +#define SSIF_IPMI_MULTI_PART_REQUEST_MIDDLE 7 +#define SSIF_IPMI_MULTI_PART_REQUEST_END 8 +#define SSIF_IPMI_RESPONSE 3 +#define SSIF_IPMI_MULTI_PART_RESPONSE_MIDDLE 9 + +/* ssif_debug is a bit-field + * SSIF_DEBUG_MSG - commands and their responses + * SSIF_DEBUG_STATES - message states + * SSIF_DEBUG_TIMING - Measure times between events in the driver + */ +#define SSIF_DEBUG_TIMING 4 +#define SSIF_DEBUG_STATE 2 +#define SSIF_DEBUG_MSG 1 +#define SSIF_NODEBUG 0 +#define SSIF_DEFAULT_DEBUG (SSIF_NODEBUG) + +/* + * Timer values + */ +#define SSIF_MSG_USEC 60000 /* 60ms between message tries (T3). */ +#define SSIF_REQ_RETRY_USEC 60000 /* 60ms between send retries (T6). */ +#define SSIF_MSG_PART_USEC 5000 /* 5ms for a message part */ + +/* How many times to we retry sending/receiving the message. */ +#define SSIF_SEND_RETRIES 5 +#define SSIF_RECV_RETRIES 250 + +#define SSIF_MSG_MSEC (SSIF_MSG_USEC / 1000) +#define SSIF_REQ_RETRY_MSEC (SSIF_REQ_RETRY_USEC / 1000) +#define SSIF_MSG_JIFFIES ((SSIF_MSG_USEC * 1000) / TICK_NSEC) +#define SSIF_REQ_RETRY_JIFFIES ((SSIF_REQ_RETRY_USEC * 1000) / TICK_NSEC) +#define SSIF_MSG_PART_JIFFIES ((SSIF_MSG_PART_USEC * 1000) / TICK_NSEC) + +/* + * Timeout for the watch, only used for get flag timer. + */ +#define SSIF_WATCH_MSG_TIMEOUT msecs_to_jiffies(10) +#define SSIF_WATCH_WATCHDOG_TIMEOUT msecs_to_jiffies(250) + +enum ssif_intf_state { + SSIF_IDLE, + SSIF_GETTING_FLAGS, + SSIF_GETTING_EVENTS, + SSIF_CLEARING_FLAGS, + SSIF_GETTING_MESSAGES, + /* FIXME - add watchdog stuff. */ +}; + +#define IS_SSIF_IDLE(ssif) ((ssif)->ssif_state == SSIF_IDLE \ + && (ssif)->curr_msg == NULL) + +/* + * Indexes into stats[] in ssif_info below. + */ +enum ssif_stat_indexes { + /* Number of total messages sent. */ + SSIF_STAT_sent_messages = 0, + + /* + * Number of message parts sent. Messages may be broken into + * parts if they are long. + */ + SSIF_STAT_sent_messages_parts, + + /* + * Number of time a message was retried. + */ + SSIF_STAT_send_retries, + + /* + * Number of times the send of a message failed. + */ + SSIF_STAT_send_errors, + + /* + * Number of message responses received. + */ + SSIF_STAT_received_messages, + + /* + * Number of message fragments received. + */ + SSIF_STAT_received_message_parts, + + /* + * Number of times the receive of a message was retried. + */ + SSIF_STAT_receive_retries, + + /* + * Number of errors receiving messages. + */ + SSIF_STAT_receive_errors, + + /* + * Number of times a flag fetch was requested. + */ + SSIF_STAT_flag_fetches, + + /* + * Number of times the hardware didn't follow the state machine. + */ + SSIF_STAT_hosed, + + /* + * Number of received events. + */ + SSIF_STAT_events, + + /* Number of asyncronous messages received. */ + SSIF_STAT_incoming_messages, + + /* Number of watchdog pretimeouts. */ + SSIF_STAT_watchdog_pretimeouts, + + /* Number of alers received. */ + SSIF_STAT_alerts, + + /* Always add statistics before this value, it must be last. */ + SSIF_NUM_STATS +}; + +struct ssif_addr_info { + struct i2c_board_info binfo; + char *adapter_name; + int debug; + int slave_addr; + enum ipmi_addr_src addr_src; + union ipmi_smi_info_union addr_info; + struct device *dev; + struct i2c_client *client; + + struct mutex clients_mutex; + struct list_head clients; + + struct list_head link; +}; + +struct ssif_info; + +typedef void (*ssif_i2c_done)(struct ssif_info *ssif_info, int result, + unsigned char *data, unsigned int len); + +struct ssif_info { + struct ipmi_smi *intf; + spinlock_t lock; + struct ipmi_smi_msg *waiting_msg; + struct ipmi_smi_msg *curr_msg; + enum ssif_intf_state ssif_state; + unsigned long ssif_debug; + + struct ipmi_smi_handlers handlers; + + enum ipmi_addr_src addr_source; /* ACPI, PCI, SMBIOS, hardcode, etc. */ + union ipmi_smi_info_union addr_info; + + /* + * Flags from the last GET_MSG_FLAGS command, used when an ATTN + * is set to hold the flags until we are done handling everything + * from the flags. + */ +#define RECEIVE_MSG_AVAIL 0x01 +#define EVENT_MSG_BUFFER_FULL 0x02 +#define WDT_PRE_TIMEOUT_INT 0x08 + unsigned char msg_flags; + + u8 global_enables; + bool has_event_buffer; + bool supports_alert; + + /* + * Used to tell what we should do with alerts. If we are + * waiting on a response, read the data immediately. + */ + bool got_alert; + bool waiting_alert; + + /* Used to inform the timeout that it should do a resend. */ + bool do_resend; + + /* + * If set to true, this will request events the next time the + * state machine is idle. + */ + bool req_events; + + /* + * If set to true, this will request flags the next time the + * state machine is idle. + */ + bool req_flags; + + /* Used for sending/receiving data. +1 for the length. */ + unsigned char data[IPMI_MAX_MSG_LENGTH + 1]; + unsigned int data_len; + + /* Temp receive buffer, gets copied into data. */ + unsigned char recv[I2C_SMBUS_BLOCK_MAX]; + + struct i2c_client *client; + ssif_i2c_done done_handler; + + /* Thread interface handling */ + struct task_struct *thread; + struct completion wake_thread; + bool stopping; + int i2c_read_write; + int i2c_command; + unsigned char *i2c_data; + unsigned int i2c_size; + + struct timer_list retry_timer; + int retries_left; + + long watch_timeout; /* Timeout for flags check, 0 if off. */ + struct timer_list watch_timer; /* Flag fetch timer. */ + + /* Info from SSIF cmd */ + unsigned char max_xmit_msg_size; + unsigned char max_recv_msg_size; + bool cmd8_works; /* See test_multipart_messages() for details. */ + unsigned int multi_support; + int supports_pec; + +#define SSIF_NO_MULTI 0 +#define SSIF_MULTI_2_PART 1 +#define SSIF_MULTI_n_PART 2 + unsigned char *multi_data; + unsigned int multi_len; + unsigned int multi_pos; + + atomic_t stats[SSIF_NUM_STATS]; +}; + +#define ssif_inc_stat(ssif, stat) \ + atomic_inc(&(ssif)->stats[SSIF_STAT_ ## stat]) +#define ssif_get_stat(ssif, stat) \ + ((unsigned int) atomic_read(&(ssif)->stats[SSIF_STAT_ ## stat])) + +static bool initialized; +static bool platform_registered; + +static void return_hosed_msg(struct ssif_info *ssif_info, + struct ipmi_smi_msg *msg); +static void start_next_msg(struct ssif_info *ssif_info, unsigned long *flags); +static int start_send(struct ssif_info *ssif_info, + unsigned char *data, + unsigned int len); + +static unsigned long *ipmi_ssif_lock_cond(struct ssif_info *ssif_info, + unsigned long *flags) + __acquires(&ssif_info->lock) +{ + spin_lock_irqsave(&ssif_info->lock, *flags); + return flags; +} + +static void ipmi_ssif_unlock_cond(struct ssif_info *ssif_info, + unsigned long *flags) + __releases(&ssif_info->lock) +{ + spin_unlock_irqrestore(&ssif_info->lock, *flags); +} + +static void deliver_recv_msg(struct ssif_info *ssif_info, + struct ipmi_smi_msg *msg) +{ + if (msg->rsp_size < 0) { + return_hosed_msg(ssif_info, msg); + dev_err(&ssif_info->client->dev, + "%s: Malformed message: rsp_size = %d\n", + __func__, msg->rsp_size); + } else { + ipmi_smi_msg_received(ssif_info->intf, msg); + } +} + +static void return_hosed_msg(struct ssif_info *ssif_info, + struct ipmi_smi_msg *msg) +{ + ssif_inc_stat(ssif_info, hosed); + + /* Make it a response */ + msg->rsp[0] = msg->data[0] | 4; + msg->rsp[1] = msg->data[1]; + msg->rsp[2] = 0xFF; /* Unknown error. */ + msg->rsp_size = 3; + + deliver_recv_msg(ssif_info, msg); +} + +/* + * Must be called with the message lock held. This will release the + * message lock. Note that the caller will check IS_SSIF_IDLE and + * start a new operation, so there is no need to check for new + * messages to start in here. + */ +static void start_clear_flags(struct ssif_info *ssif_info, unsigned long *flags) +{ + unsigned char msg[3]; + + ssif_info->msg_flags &= ~WDT_PRE_TIMEOUT_INT; + ssif_info->ssif_state = SSIF_CLEARING_FLAGS; + ipmi_ssif_unlock_cond(ssif_info, flags); + + /* Make sure the watchdog pre-timeout flag is not set at startup. */ + msg[0] = (IPMI_NETFN_APP_REQUEST << 2); + msg[1] = IPMI_CLEAR_MSG_FLAGS_CMD; + msg[2] = WDT_PRE_TIMEOUT_INT; + + if (start_send(ssif_info, msg, 3) != 0) { + /* Error, just go to normal state. */ + ssif_info->ssif_state = SSIF_IDLE; + } +} + +static void start_flag_fetch(struct ssif_info *ssif_info, unsigned long *flags) +{ + unsigned char mb[2]; + + ssif_info->req_flags = false; + ssif_info->ssif_state = SSIF_GETTING_FLAGS; + ipmi_ssif_unlock_cond(ssif_info, flags); + + mb[0] = (IPMI_NETFN_APP_REQUEST << 2); + mb[1] = IPMI_GET_MSG_FLAGS_CMD; + if (start_send(ssif_info, mb, 2) != 0) + ssif_info->ssif_state = SSIF_IDLE; +} + +static void check_start_send(struct ssif_info *ssif_info, unsigned long *flags, + struct ipmi_smi_msg *msg) +{ + if (start_send(ssif_info, msg->data, msg->data_size) != 0) { + unsigned long oflags; + + flags = ipmi_ssif_lock_cond(ssif_info, &oflags); + ssif_info->curr_msg = NULL; + ssif_info->ssif_state = SSIF_IDLE; + ipmi_ssif_unlock_cond(ssif_info, flags); + ipmi_free_smi_msg(msg); + } +} + +static void start_event_fetch(struct ssif_info *ssif_info, unsigned long *flags) +{ + struct ipmi_smi_msg *msg; + + ssif_info->req_events = false; + + msg = ipmi_alloc_smi_msg(); + if (!msg) { + ssif_info->ssif_state = SSIF_IDLE; + ipmi_ssif_unlock_cond(ssif_info, flags); + return; + } + + ssif_info->curr_msg = msg; + ssif_info->ssif_state = SSIF_GETTING_EVENTS; + ipmi_ssif_unlock_cond(ssif_info, flags); + + msg->data[0] = (IPMI_NETFN_APP_REQUEST << 2); + msg->data[1] = IPMI_READ_EVENT_MSG_BUFFER_CMD; + msg->data_size = 2; + + check_start_send(ssif_info, flags, msg); +} + +static void start_recv_msg_fetch(struct ssif_info *ssif_info, + unsigned long *flags) +{ + struct ipmi_smi_msg *msg; + + msg = ipmi_alloc_smi_msg(); + if (!msg) { + ssif_info->ssif_state = SSIF_IDLE; + ipmi_ssif_unlock_cond(ssif_info, flags); + return; + } + + ssif_info->curr_msg = msg; + ssif_info->ssif_state = SSIF_GETTING_MESSAGES; + ipmi_ssif_unlock_cond(ssif_info, flags); + + msg->data[0] = (IPMI_NETFN_APP_REQUEST << 2); + msg->data[1] = IPMI_GET_MSG_CMD; + msg->data_size = 2; + + check_start_send(ssif_info, flags, msg); +} + +/* + * Must be called with the message lock held. This will release the + * message lock. Note that the caller will check IS_SSIF_IDLE and + * start a new operation, so there is no need to check for new + * messages to start in here. + */ +static void handle_flags(struct ssif_info *ssif_info, unsigned long *flags) +{ + if (ssif_info->msg_flags & WDT_PRE_TIMEOUT_INT) { + /* Watchdog pre-timeout */ + ssif_inc_stat(ssif_info, watchdog_pretimeouts); + start_clear_flags(ssif_info, flags); + ipmi_smi_watchdog_pretimeout(ssif_info->intf); + } else if (ssif_info->msg_flags & RECEIVE_MSG_AVAIL) + /* Messages available. */ + start_recv_msg_fetch(ssif_info, flags); + else if (ssif_info->msg_flags & EVENT_MSG_BUFFER_FULL) + /* Events available. */ + start_event_fetch(ssif_info, flags); + else { + ssif_info->ssif_state = SSIF_IDLE; + ipmi_ssif_unlock_cond(ssif_info, flags); + } +} + +static int ipmi_ssif_thread(void *data) +{ + struct ssif_info *ssif_info = data; + + while (!kthread_should_stop()) { + int result; + + /* Wait for something to do */ + result = wait_for_completion_interruptible( + &ssif_info->wake_thread); + if (ssif_info->stopping) + break; + if (result == -ERESTARTSYS) + continue; + init_completion(&ssif_info->wake_thread); + + if (ssif_info->i2c_read_write == I2C_SMBUS_WRITE) { + result = i2c_smbus_write_block_data( + ssif_info->client, ssif_info->i2c_command, + ssif_info->i2c_data[0], + ssif_info->i2c_data + 1); + ssif_info->done_handler(ssif_info, result, NULL, 0); + } else { + result = i2c_smbus_read_block_data( + ssif_info->client, ssif_info->i2c_command, + ssif_info->i2c_data); + if (result < 0) + ssif_info->done_handler(ssif_info, result, + NULL, 0); + else + ssif_info->done_handler(ssif_info, 0, + ssif_info->i2c_data, + result); + } + } + + return 0; +} + +static void ssif_i2c_send(struct ssif_info *ssif_info, + ssif_i2c_done handler, + int read_write, int command, + unsigned char *data, unsigned int size) +{ + ssif_info->done_handler = handler; + + ssif_info->i2c_read_write = read_write; + ssif_info->i2c_command = command; + ssif_info->i2c_data = data; + ssif_info->i2c_size = size; + complete(&ssif_info->wake_thread); +} + + +static void msg_done_handler(struct ssif_info *ssif_info, int result, + unsigned char *data, unsigned int len); + +static void start_get(struct ssif_info *ssif_info) +{ + ssif_info->multi_pos = 0; + + ssif_i2c_send(ssif_info, msg_done_handler, I2C_SMBUS_READ, + SSIF_IPMI_RESPONSE, + ssif_info->recv, I2C_SMBUS_BLOCK_DATA); +} + +static void start_resend(struct ssif_info *ssif_info); + +static void retry_timeout(struct timer_list *t) +{ + struct ssif_info *ssif_info = from_timer(ssif_info, t, retry_timer); + unsigned long oflags, *flags; + bool waiting, resend; + + if (ssif_info->stopping) + return; + + flags = ipmi_ssif_lock_cond(ssif_info, &oflags); + resend = ssif_info->do_resend; + ssif_info->do_resend = false; + waiting = ssif_info->waiting_alert; + ssif_info->waiting_alert = false; + ipmi_ssif_unlock_cond(ssif_info, flags); + + if (waiting) + start_get(ssif_info); + if (resend) { + start_resend(ssif_info); + ssif_inc_stat(ssif_info, send_retries); + } +} + +static void watch_timeout(struct timer_list *t) +{ + struct ssif_info *ssif_info = from_timer(ssif_info, t, watch_timer); + unsigned long oflags, *flags; + + if (ssif_info->stopping) + return; + + flags = ipmi_ssif_lock_cond(ssif_info, &oflags); + if (ssif_info->watch_timeout) { + mod_timer(&ssif_info->watch_timer, + jiffies + ssif_info->watch_timeout); + if (IS_SSIF_IDLE(ssif_info)) { + start_flag_fetch(ssif_info, flags); /* Releases lock */ + return; + } + ssif_info->req_flags = true; + } + ipmi_ssif_unlock_cond(ssif_info, flags); +} + +static void ssif_alert(struct i2c_client *client, enum i2c_alert_protocol type, + unsigned int data) +{ + struct ssif_info *ssif_info = i2c_get_clientdata(client); + unsigned long oflags, *flags; + bool do_get = false; + + if (type != I2C_PROTOCOL_SMBUS_ALERT) + return; + + ssif_inc_stat(ssif_info, alerts); + + flags = ipmi_ssif_lock_cond(ssif_info, &oflags); + if (ssif_info->waiting_alert) { + ssif_info->waiting_alert = false; + del_timer(&ssif_info->retry_timer); + do_get = true; + } else if (ssif_info->curr_msg) { + ssif_info->got_alert = true; + } + ipmi_ssif_unlock_cond(ssif_info, flags); + if (do_get) + start_get(ssif_info); +} + +static void msg_done_handler(struct ssif_info *ssif_info, int result, + unsigned char *data, unsigned int len) +{ + struct ipmi_smi_msg *msg; + unsigned long oflags, *flags; + + /* + * We are single-threaded here, so no need for a lock until we + * start messing with driver states or the queues. + */ + + if (result < 0) { + ssif_info->retries_left--; + if (ssif_info->retries_left > 0) { + ssif_inc_stat(ssif_info, receive_retries); + + flags = ipmi_ssif_lock_cond(ssif_info, &oflags); + ssif_info->waiting_alert = true; + if (!ssif_info->stopping) + mod_timer(&ssif_info->retry_timer, + jiffies + SSIF_MSG_JIFFIES); + ipmi_ssif_unlock_cond(ssif_info, flags); + return; + } + + ssif_inc_stat(ssif_info, receive_errors); + + if (ssif_info->ssif_debug & SSIF_DEBUG_MSG) + dev_dbg(&ssif_info->client->dev, + "%s: Error %d\n", __func__, result); + len = 0; + goto continue_op; + } + + if ((len > 1) && (ssif_info->multi_pos == 0) + && (data[0] == 0x00) && (data[1] == 0x01)) { + /* Start of multi-part read. Start the next transaction. */ + int i; + + ssif_inc_stat(ssif_info, received_message_parts); + + /* Remove the multi-part read marker. */ + len -= 2; + data += 2; + for (i = 0; i < len; i++) + ssif_info->data[i] = data[i]; + ssif_info->multi_len = len; + ssif_info->multi_pos = 1; + + ssif_i2c_send(ssif_info, msg_done_handler, I2C_SMBUS_READ, + SSIF_IPMI_MULTI_PART_RESPONSE_MIDDLE, + ssif_info->recv, I2C_SMBUS_BLOCK_DATA); + return; + } else if (ssif_info->multi_pos) { + /* Middle of multi-part read. Start the next transaction. */ + int i; + unsigned char blocknum; + + if (len == 0) { + result = -EIO; + if (ssif_info->ssif_debug & SSIF_DEBUG_MSG) + dev_dbg(&ssif_info->client->dev, + "Middle message with no data\n"); + + goto continue_op; + } + + blocknum = data[0]; + len--; + data++; + + if (blocknum != 0xff && len != 31) { + /* All blocks but the last must have 31 data bytes. */ + result = -EIO; + if (ssif_info->ssif_debug & SSIF_DEBUG_MSG) + dev_dbg(&ssif_info->client->dev, + "Received middle message <31\n"); + + goto continue_op; + } + + if (ssif_info->multi_len + len > IPMI_MAX_MSG_LENGTH) { + /* Received message too big, abort the operation. */ + result = -E2BIG; + if (ssif_info->ssif_debug & SSIF_DEBUG_MSG) + dev_dbg(&ssif_info->client->dev, + "Received message too big\n"); + + goto continue_op; + } + + for (i = 0; i < len; i++) + ssif_info->data[i + ssif_info->multi_len] = data[i]; + ssif_info->multi_len += len; + if (blocknum == 0xff) { + /* End of read */ + len = ssif_info->multi_len; + data = ssif_info->data; + } else if (blocknum + 1 != ssif_info->multi_pos) { + /* + * Out of sequence block, just abort. Block + * numbers start at zero for the second block, + * but multi_pos starts at one, so the +1. + */ + if (ssif_info->ssif_debug & SSIF_DEBUG_MSG) + dev_dbg(&ssif_info->client->dev, + "Received message out of sequence, expected %u, got %u\n", + ssif_info->multi_pos - 1, blocknum); + result = -EIO; + } else { + ssif_inc_stat(ssif_info, received_message_parts); + + ssif_info->multi_pos++; + + ssif_i2c_send(ssif_info, msg_done_handler, + I2C_SMBUS_READ, + SSIF_IPMI_MULTI_PART_RESPONSE_MIDDLE, + ssif_info->recv, + I2C_SMBUS_BLOCK_DATA); + return; + } + } + + continue_op: + if (result < 0) { + ssif_inc_stat(ssif_info, receive_errors); + } else { + ssif_inc_stat(ssif_info, received_messages); + ssif_inc_stat(ssif_info, received_message_parts); + } + + if (ssif_info->ssif_debug & SSIF_DEBUG_STATE) + dev_dbg(&ssif_info->client->dev, + "DONE 1: state = %d, result=%d\n", + ssif_info->ssif_state, result); + + flags = ipmi_ssif_lock_cond(ssif_info, &oflags); + msg = ssif_info->curr_msg; + if (msg) { + if (data) { + if (len > IPMI_MAX_MSG_LENGTH) + len = IPMI_MAX_MSG_LENGTH; + memcpy(msg->rsp, data, len); + } else { + len = 0; + } + msg->rsp_size = len; + ssif_info->curr_msg = NULL; + } + + switch (ssif_info->ssif_state) { + case SSIF_IDLE: + ipmi_ssif_unlock_cond(ssif_info, flags); + if (!msg) + break; + + if (result < 0) + return_hosed_msg(ssif_info, msg); + else + deliver_recv_msg(ssif_info, msg); + break; + + case SSIF_GETTING_FLAGS: + /* We got the flags from the SSIF, now handle them. */ + if ((result < 0) || (len < 4) || (data[2] != 0)) { + /* + * Error fetching flags, or invalid length, + * just give up for now. + */ + ssif_info->ssif_state = SSIF_IDLE; + ipmi_ssif_unlock_cond(ssif_info, flags); + dev_warn(&ssif_info->client->dev, + "Error getting flags: %d %d, %x\n", + result, len, (len >= 3) ? data[2] : 0); + } else if (data[0] != (IPMI_NETFN_APP_REQUEST | 1) << 2 + || data[1] != IPMI_GET_MSG_FLAGS_CMD) { + /* + * Recv error response, give up. + */ + ssif_info->ssif_state = SSIF_IDLE; + ipmi_ssif_unlock_cond(ssif_info, flags); + dev_warn(&ssif_info->client->dev, + "Invalid response getting flags: %x %x\n", + data[0], data[1]); + } else { + ssif_inc_stat(ssif_info, flag_fetches); + ssif_info->msg_flags = data[3]; + handle_flags(ssif_info, flags); + } + break; + + case SSIF_CLEARING_FLAGS: + /* We cleared the flags. */ + if ((result < 0) || (len < 3) || (data[2] != 0)) { + /* Error clearing flags */ + dev_warn(&ssif_info->client->dev, + "Error clearing flags: %d %d, %x\n", + result, len, (len >= 3) ? data[2] : 0); + } else if (data[0] != (IPMI_NETFN_APP_REQUEST | 1) << 2 + || data[1] != IPMI_CLEAR_MSG_FLAGS_CMD) { + dev_warn(&ssif_info->client->dev, + "Invalid response clearing flags: %x %x\n", + data[0], data[1]); + } + ssif_info->ssif_state = SSIF_IDLE; + ipmi_ssif_unlock_cond(ssif_info, flags); + break; + + case SSIF_GETTING_EVENTS: + if (!msg) { + /* Should never happen, but just in case. */ + dev_warn(&ssif_info->client->dev, + "No message set while getting events\n"); + ipmi_ssif_unlock_cond(ssif_info, flags); + break; + } + + if ((result < 0) || (len < 3) || (msg->rsp[2] != 0)) { + /* Error getting event, probably done. */ + msg->done(msg); + + /* Take off the event flag. */ + ssif_info->msg_flags &= ~EVENT_MSG_BUFFER_FULL; + handle_flags(ssif_info, flags); + } else if (msg->rsp[0] != (IPMI_NETFN_APP_REQUEST | 1) << 2 + || msg->rsp[1] != IPMI_READ_EVENT_MSG_BUFFER_CMD) { + dev_warn(&ssif_info->client->dev, + "Invalid response getting events: %x %x\n", + msg->rsp[0], msg->rsp[1]); + msg->done(msg); + /* Take off the event flag. */ + ssif_info->msg_flags &= ~EVENT_MSG_BUFFER_FULL; + handle_flags(ssif_info, flags); + } else { + handle_flags(ssif_info, flags); + ssif_inc_stat(ssif_info, events); + deliver_recv_msg(ssif_info, msg); + } + break; + + case SSIF_GETTING_MESSAGES: + if (!msg) { + /* Should never happen, but just in case. */ + dev_warn(&ssif_info->client->dev, + "No message set while getting messages\n"); + ipmi_ssif_unlock_cond(ssif_info, flags); + break; + } + + if ((result < 0) || (len < 3) || (msg->rsp[2] != 0)) { + /* Error getting event, probably done. */ + msg->done(msg); + + /* Take off the msg flag. */ + ssif_info->msg_flags &= ~RECEIVE_MSG_AVAIL; + handle_flags(ssif_info, flags); + } else if (msg->rsp[0] != (IPMI_NETFN_APP_REQUEST | 1) << 2 + || msg->rsp[1] != IPMI_GET_MSG_CMD) { + dev_warn(&ssif_info->client->dev, + "Invalid response clearing flags: %x %x\n", + msg->rsp[0], msg->rsp[1]); + msg->done(msg); + + /* Take off the msg flag. */ + ssif_info->msg_flags &= ~RECEIVE_MSG_AVAIL; + handle_flags(ssif_info, flags); + } else { + ssif_inc_stat(ssif_info, incoming_messages); + handle_flags(ssif_info, flags); + deliver_recv_msg(ssif_info, msg); + } + break; + + default: + /* Should never happen, but just in case. */ + dev_warn(&ssif_info->client->dev, + "Invalid state in message done handling: %d\n", + ssif_info->ssif_state); + ipmi_ssif_unlock_cond(ssif_info, flags); + } + + flags = ipmi_ssif_lock_cond(ssif_info, &oflags); + if (IS_SSIF_IDLE(ssif_info) && !ssif_info->stopping) { + if (ssif_info->req_events) + start_event_fetch(ssif_info, flags); + else if (ssif_info->req_flags) + start_flag_fetch(ssif_info, flags); + else + start_next_msg(ssif_info, flags); + } else + ipmi_ssif_unlock_cond(ssif_info, flags); + + if (ssif_info->ssif_debug & SSIF_DEBUG_STATE) + dev_dbg(&ssif_info->client->dev, + "DONE 2: state = %d.\n", ssif_info->ssif_state); +} + +static void msg_written_handler(struct ssif_info *ssif_info, int result, + unsigned char *data, unsigned int len) +{ + /* We are single-threaded here, so no need for a lock. */ + if (result < 0) { + ssif_info->retries_left--; + if (ssif_info->retries_left > 0) { + /* + * Wait the retry timeout time per the spec, + * then redo the send. + */ + ssif_info->do_resend = true; + mod_timer(&ssif_info->retry_timer, + jiffies + SSIF_REQ_RETRY_JIFFIES); + return; + } + + ssif_inc_stat(ssif_info, send_errors); + + if (ssif_info->ssif_debug & SSIF_DEBUG_MSG) + dev_dbg(&ssif_info->client->dev, + "%s: Out of retries\n", __func__); + + msg_done_handler(ssif_info, -EIO, NULL, 0); + return; + } + + if (ssif_info->multi_data) { + /* + * In the middle of a multi-data write. See the comment + * in the SSIF_MULTI_n_PART case in the probe function + * for details on the intricacies of this. + */ + int left, to_write; + unsigned char *data_to_send; + unsigned char cmd; + + ssif_inc_stat(ssif_info, sent_messages_parts); + + left = ssif_info->multi_len - ssif_info->multi_pos; + to_write = left; + if (to_write > 32) + to_write = 32; + /* Length byte. */ + ssif_info->multi_data[ssif_info->multi_pos] = to_write; + data_to_send = ssif_info->multi_data + ssif_info->multi_pos; + ssif_info->multi_pos += to_write; + cmd = SSIF_IPMI_MULTI_PART_REQUEST_MIDDLE; + if (ssif_info->cmd8_works) { + if (left == to_write) { + cmd = SSIF_IPMI_MULTI_PART_REQUEST_END; + ssif_info->multi_data = NULL; + } + } else if (to_write < 32) { + ssif_info->multi_data = NULL; + } + + ssif_i2c_send(ssif_info, msg_written_handler, + I2C_SMBUS_WRITE, cmd, + data_to_send, I2C_SMBUS_BLOCK_DATA); + } else { + /* Ready to request the result. */ + unsigned long oflags, *flags; + + ssif_inc_stat(ssif_info, sent_messages); + ssif_inc_stat(ssif_info, sent_messages_parts); + + flags = ipmi_ssif_lock_cond(ssif_info, &oflags); + if (ssif_info->got_alert) { + /* The result is already ready, just start it. */ + ssif_info->got_alert = false; + ipmi_ssif_unlock_cond(ssif_info, flags); + start_get(ssif_info); + } else { + /* Wait a jiffie then request the next message */ + ssif_info->waiting_alert = true; + ssif_info->retries_left = SSIF_RECV_RETRIES; + if (!ssif_info->stopping) + mod_timer(&ssif_info->retry_timer, + jiffies + SSIF_MSG_PART_JIFFIES); + ipmi_ssif_unlock_cond(ssif_info, flags); + } + } +} + +static void start_resend(struct ssif_info *ssif_info) +{ + int command; + + ssif_info->got_alert = false; + + if (ssif_info->data_len > 32) { + command = SSIF_IPMI_MULTI_PART_REQUEST_START; + ssif_info->multi_data = ssif_info->data; + ssif_info->multi_len = ssif_info->data_len; + /* + * Subtle thing, this is 32, not 33, because we will + * overwrite the thing at position 32 (which was just + * transmitted) with the new length. + */ + ssif_info->multi_pos = 32; + ssif_info->data[0] = 32; + } else { + ssif_info->multi_data = NULL; + command = SSIF_IPMI_REQUEST; + ssif_info->data[0] = ssif_info->data_len; + } + + ssif_i2c_send(ssif_info, msg_written_handler, I2C_SMBUS_WRITE, + command, ssif_info->data, I2C_SMBUS_BLOCK_DATA); +} + +static int start_send(struct ssif_info *ssif_info, + unsigned char *data, + unsigned int len) +{ + if (len > IPMI_MAX_MSG_LENGTH) + return -E2BIG; + if (len > ssif_info->max_xmit_msg_size) + return -E2BIG; + + ssif_info->retries_left = SSIF_SEND_RETRIES; + memcpy(ssif_info->data + 1, data, len); + ssif_info->data_len = len; + start_resend(ssif_info); + return 0; +} + +/* Must be called with the message lock held. */ +static void start_next_msg(struct ssif_info *ssif_info, unsigned long *flags) +{ + struct ipmi_smi_msg *msg; + unsigned long oflags; + + restart: + if (!IS_SSIF_IDLE(ssif_info)) { + ipmi_ssif_unlock_cond(ssif_info, flags); + return; + } + + if (!ssif_info->waiting_msg) { + ssif_info->curr_msg = NULL; + ipmi_ssif_unlock_cond(ssif_info, flags); + } else { + int rv; + + ssif_info->curr_msg = ssif_info->waiting_msg; + ssif_info->waiting_msg = NULL; + ipmi_ssif_unlock_cond(ssif_info, flags); + rv = start_send(ssif_info, + ssif_info->curr_msg->data, + ssif_info->curr_msg->data_size); + if (rv) { + msg = ssif_info->curr_msg; + ssif_info->curr_msg = NULL; + return_hosed_msg(ssif_info, msg); + flags = ipmi_ssif_lock_cond(ssif_info, &oflags); + goto restart; + } + } +} + +static void sender(void *send_info, + struct ipmi_smi_msg *msg) +{ + struct ssif_info *ssif_info = send_info; + unsigned long oflags, *flags; + + BUG_ON(ssif_info->waiting_msg); + ssif_info->waiting_msg = msg; + + flags = ipmi_ssif_lock_cond(ssif_info, &oflags); + start_next_msg(ssif_info, flags); + + if (ssif_info->ssif_debug & SSIF_DEBUG_TIMING) { + struct timespec64 t; + + ktime_get_real_ts64(&t); + dev_dbg(&ssif_info->client->dev, + "**Enqueue %02x %02x: %lld.%6.6ld\n", + msg->data[0], msg->data[1], + (long long)t.tv_sec, (long)t.tv_nsec / NSEC_PER_USEC); + } +} + +static int get_smi_info(void *send_info, struct ipmi_smi_info *data) +{ + struct ssif_info *ssif_info = send_info; + + data->addr_src = ssif_info->addr_source; + data->dev = &ssif_info->client->dev; + data->addr_info = ssif_info->addr_info; + get_device(data->dev); + + return 0; +} + +/* + * Upper layer wants us to request events. + */ +static void request_events(void *send_info) +{ + struct ssif_info *ssif_info = send_info; + unsigned long oflags, *flags; + + if (!ssif_info->has_event_buffer) + return; + + flags = ipmi_ssif_lock_cond(ssif_info, &oflags); + ssif_info->req_events = true; + ipmi_ssif_unlock_cond(ssif_info, flags); +} + +/* + * Upper layer is changing the flag saying whether we need to request + * flags periodically or not. + */ +static void ssif_set_need_watch(void *send_info, unsigned int watch_mask) +{ + struct ssif_info *ssif_info = send_info; + unsigned long oflags, *flags; + long timeout = 0; + + if (watch_mask & IPMI_WATCH_MASK_CHECK_MESSAGES) + timeout = SSIF_WATCH_MSG_TIMEOUT; + else if (watch_mask) + timeout = SSIF_WATCH_WATCHDOG_TIMEOUT; + + flags = ipmi_ssif_lock_cond(ssif_info, &oflags); + if (timeout != ssif_info->watch_timeout) { + ssif_info->watch_timeout = timeout; + if (ssif_info->watch_timeout) + mod_timer(&ssif_info->watch_timer, + jiffies + ssif_info->watch_timeout); + } + ipmi_ssif_unlock_cond(ssif_info, flags); +} + +static int ssif_start_processing(void *send_info, + struct ipmi_smi *intf) +{ + struct ssif_info *ssif_info = send_info; + + ssif_info->intf = intf; + + return 0; +} + +#define MAX_SSIF_BMCS 4 + +static unsigned short addr[MAX_SSIF_BMCS]; +static int num_addrs; +module_param_array(addr, ushort, &num_addrs, 0); +MODULE_PARM_DESC(addr, "The addresses to scan for IPMI BMCs on the SSIFs."); + +static char *adapter_name[MAX_SSIF_BMCS]; +static int num_adapter_names; +module_param_array(adapter_name, charp, &num_adapter_names, 0); +MODULE_PARM_DESC(adapter_name, "The string name of the I2C device that has the BMC. By default all devices are scanned."); + +static int slave_addrs[MAX_SSIF_BMCS]; +static int num_slave_addrs; +module_param_array(slave_addrs, int, &num_slave_addrs, 0); +MODULE_PARM_DESC(slave_addrs, + "The default IPMB slave address for the controller."); + +static bool alerts_broken; +module_param(alerts_broken, bool, 0); +MODULE_PARM_DESC(alerts_broken, "Don't enable alerts for the controller."); + +/* + * Bit 0 enables message debugging, bit 1 enables state debugging, and + * bit 2 enables timing debugging. This is an array indexed by + * interface number" + */ +static int dbg[MAX_SSIF_BMCS]; +static int num_dbg; +module_param_array(dbg, int, &num_dbg, 0); +MODULE_PARM_DESC(dbg, "Turn on debugging."); + +static bool ssif_dbg_probe; +module_param_named(dbg_probe, ssif_dbg_probe, bool, 0); +MODULE_PARM_DESC(dbg_probe, "Enable debugging of probing of adapters."); + +static bool ssif_tryacpi = true; +module_param_named(tryacpi, ssif_tryacpi, bool, 0); +MODULE_PARM_DESC(tryacpi, "Setting this to zero will disable the default scan of the interfaces identified via ACPI"); + +static bool ssif_trydmi = true; +module_param_named(trydmi, ssif_trydmi, bool, 0); +MODULE_PARM_DESC(trydmi, "Setting this to zero will disable the default scan of the interfaces identified via DMI (SMBIOS)"); + +static DEFINE_MUTEX(ssif_infos_mutex); +static LIST_HEAD(ssif_infos); + +#define IPMI_SSIF_ATTR(name) \ +static ssize_t ipmi_##name##_show(struct device *dev, \ + struct device_attribute *attr, \ + char *buf) \ +{ \ + struct ssif_info *ssif_info = dev_get_drvdata(dev); \ + \ + return sysfs_emit(buf, "%u\n", ssif_get_stat(ssif_info, name));\ +} \ +static DEVICE_ATTR(name, S_IRUGO, ipmi_##name##_show, NULL) + +static ssize_t ipmi_type_show(struct device *dev, + struct device_attribute *attr, + char *buf) +{ + return sysfs_emit(buf, "ssif\n"); +} +static DEVICE_ATTR(type, S_IRUGO, ipmi_type_show, NULL); + +IPMI_SSIF_ATTR(sent_messages); +IPMI_SSIF_ATTR(sent_messages_parts); +IPMI_SSIF_ATTR(send_retries); +IPMI_SSIF_ATTR(send_errors); +IPMI_SSIF_ATTR(received_messages); +IPMI_SSIF_ATTR(received_message_parts); +IPMI_SSIF_ATTR(receive_retries); +IPMI_SSIF_ATTR(receive_errors); +IPMI_SSIF_ATTR(flag_fetches); +IPMI_SSIF_ATTR(hosed); +IPMI_SSIF_ATTR(events); +IPMI_SSIF_ATTR(watchdog_pretimeouts); +IPMI_SSIF_ATTR(alerts); + +static struct attribute *ipmi_ssif_dev_attrs[] = { + &dev_attr_type.attr, + &dev_attr_sent_messages.attr, + &dev_attr_sent_messages_parts.attr, + &dev_attr_send_retries.attr, + &dev_attr_send_errors.attr, + &dev_attr_received_messages.attr, + &dev_attr_received_message_parts.attr, + &dev_attr_receive_retries.attr, + &dev_attr_receive_errors.attr, + &dev_attr_flag_fetches.attr, + &dev_attr_hosed.attr, + &dev_attr_events.attr, + &dev_attr_watchdog_pretimeouts.attr, + &dev_attr_alerts.attr, + NULL +}; + +static const struct attribute_group ipmi_ssif_dev_attr_group = { + .attrs = ipmi_ssif_dev_attrs, +}; + +static void shutdown_ssif(void *send_info) +{ + struct ssif_info *ssif_info = send_info; + + device_remove_group(&ssif_info->client->dev, &ipmi_ssif_dev_attr_group); + dev_set_drvdata(&ssif_info->client->dev, NULL); + + /* make sure the driver is not looking for flags any more. */ + while (ssif_info->ssif_state != SSIF_IDLE) + schedule_timeout(1); + + ssif_info->stopping = true; + del_timer_sync(&ssif_info->watch_timer); + del_timer_sync(&ssif_info->retry_timer); + if (ssif_info->thread) { + complete(&ssif_info->wake_thread); + kthread_stop(ssif_info->thread); + } +} + +static void ssif_remove(struct i2c_client *client) +{ + struct ssif_info *ssif_info = i2c_get_clientdata(client); + struct ssif_addr_info *addr_info; + + /* + * After this point, we won't deliver anything asynchronously + * to the message handler. We can unregister ourself. + */ + ipmi_unregister_smi(ssif_info->intf); + + list_for_each_entry(addr_info, &ssif_infos, link) { + if (addr_info->client == client) { + addr_info->client = NULL; + break; + } + } + + kfree(ssif_info); +} + +static int read_response(struct i2c_client *client, unsigned char *resp) +{ + int ret = -ENODEV, retry_cnt = SSIF_RECV_RETRIES; + + while (retry_cnt > 0) { + ret = i2c_smbus_read_block_data(client, SSIF_IPMI_RESPONSE, + resp); + if (ret > 0) + break; + msleep(SSIF_MSG_MSEC); + retry_cnt--; + if (retry_cnt <= 0) + break; + } + + return ret; +} + +static int do_cmd(struct i2c_client *client, int len, unsigned char *msg, + int *resp_len, unsigned char *resp) +{ + int retry_cnt; + int ret; + + retry_cnt = SSIF_SEND_RETRIES; + retry1: + ret = i2c_smbus_write_block_data(client, SSIF_IPMI_REQUEST, len, msg); + if (ret) { + retry_cnt--; + if (retry_cnt > 0) { + msleep(SSIF_REQ_RETRY_MSEC); + goto retry1; + } + return -ENODEV; + } + + ret = read_response(client, resp); + if (ret > 0) { + /* Validate that the response is correct. */ + if (ret < 3 || + (resp[0] != (msg[0] | (1 << 2))) || + (resp[1] != msg[1])) + ret = -EINVAL; + else if (ret > IPMI_MAX_MSG_LENGTH) { + ret = -E2BIG; + } else { + *resp_len = ret; + ret = 0; + } + } + + return ret; +} + +static int ssif_detect(struct i2c_client *client, struct i2c_board_info *info) +{ + unsigned char *resp; + unsigned char msg[3]; + int rv; + int len; + + resp = kmalloc(IPMI_MAX_MSG_LENGTH, GFP_KERNEL); + if (!resp) + return -ENOMEM; + + /* Do a Get Device ID command, since it is required. */ + msg[0] = IPMI_NETFN_APP_REQUEST << 2; + msg[1] = IPMI_GET_DEVICE_ID_CMD; + rv = do_cmd(client, 2, msg, &len, resp); + if (rv) + rv = -ENODEV; + else + strscpy(info->type, DEVICE_NAME, I2C_NAME_SIZE); + kfree(resp); + return rv; +} + +static int strcmp_nospace(char *s1, char *s2) +{ + while (*s1 && *s2) { + while (isspace(*s1)) + s1++; + while (isspace(*s2)) + s2++; + if (*s1 > *s2) + return 1; + if (*s1 < *s2) + return -1; + s1++; + s2++; + } + return 0; +} + +static struct ssif_addr_info *ssif_info_find(unsigned short addr, + char *adapter_name, + bool match_null_name) +{ + struct ssif_addr_info *info, *found = NULL; + +restart: + list_for_each_entry(info, &ssif_infos, link) { + if (info->binfo.addr == addr) { + if (info->addr_src == SI_SMBIOS && !info->adapter_name) + info->adapter_name = kstrdup(adapter_name, + GFP_KERNEL); + + if (info->adapter_name || adapter_name) { + if (!info->adapter_name != !adapter_name) { + /* One is NULL and one is not */ + continue; + } + if (adapter_name && + strcmp_nospace(info->adapter_name, + adapter_name)) + /* Names do not match */ + continue; + } + found = info; + break; + } + } + + if (!found && match_null_name) { + /* Try to get an exact match first, then try with a NULL name */ + adapter_name = NULL; + match_null_name = false; + goto restart; + } + + return found; +} + +static bool check_acpi(struct ssif_info *ssif_info, struct device *dev) +{ +#ifdef CONFIG_ACPI + acpi_handle acpi_handle; + + acpi_handle = ACPI_HANDLE(dev); + if (acpi_handle) { + ssif_info->addr_source = SI_ACPI; + ssif_info->addr_info.acpi_info.acpi_handle = acpi_handle; + request_module_nowait("acpi_ipmi"); + return true; + } +#endif + return false; +} + +static int find_slave_address(struct i2c_client *client, int slave_addr) +{ +#ifdef CONFIG_IPMI_DMI_DECODE + if (!slave_addr) + slave_addr = ipmi_dmi_get_slave_addr( + SI_TYPE_INVALID, + i2c_adapter_id(client->adapter), + client->addr); +#endif + + return slave_addr; +} + +static int start_multipart_test(struct i2c_client *client, + unsigned char *msg, bool do_middle) +{ + int retry_cnt = SSIF_SEND_RETRIES, ret; + +retry_write: + ret = i2c_smbus_write_block_data(client, + SSIF_IPMI_MULTI_PART_REQUEST_START, + 32, msg); + if (ret) { + retry_cnt--; + if (retry_cnt > 0) { + msleep(SSIF_REQ_RETRY_MSEC); + goto retry_write; + } + dev_err(&client->dev, "Could not write multi-part start, though the BMC said it could handle it. Just limit sends to one part.\n"); + return ret; + } + + if (!do_middle) + return 0; + + ret = i2c_smbus_write_block_data(client, + SSIF_IPMI_MULTI_PART_REQUEST_MIDDLE, + 32, msg + 32); + if (ret) { + dev_err(&client->dev, "Could not write multi-part middle, though the BMC said it could handle it. Just limit sends to one part.\n"); + return ret; + } + + return 0; +} + +static void test_multipart_messages(struct i2c_client *client, + struct ssif_info *ssif_info, + unsigned char *resp) +{ + unsigned char msg[65]; + int ret; + bool do_middle; + + if (ssif_info->max_xmit_msg_size <= 32) + return; + + do_middle = ssif_info->max_xmit_msg_size > 63; + + memset(msg, 0, sizeof(msg)); + msg[0] = IPMI_NETFN_APP_REQUEST << 2; + msg[1] = IPMI_GET_DEVICE_ID_CMD; + + /* + * The specification is all messed up dealing with sending + * multi-part messages. Per what the specification says, it + * is impossible to send a message that is a multiple of 32 + * bytes, except for 32 itself. It talks about a "start" + * transaction (cmd=6) that must be 32 bytes, "middle" + * transaction (cmd=7) that must be 32 bytes, and an "end" + * transaction. The "end" transaction is shown as cmd=7 in + * the text, but if that's the case there is no way to + * differentiate between a middle and end part except the + * length being less than 32. But there is a table at the far + * end of the section (that I had never noticed until someone + * pointed it out to me) that mentions it as cmd=8. + * + * After some thought, I think the example is wrong and the + * end transaction should be cmd=8. But some systems don't + * implement cmd=8, they use a zero-length end transaction, + * even though that violates the SMBus specification. + * + * So, to work around this, this code tests if cmd=8 works. + * If it does, then we use that. If not, it tests zero- + * byte end transactions. If that works, good. If not, + * we only allow 63-byte transactions max. + */ + + ret = start_multipart_test(client, msg, do_middle); + if (ret) + goto out_no_multi_part; + + ret = i2c_smbus_write_block_data(client, + SSIF_IPMI_MULTI_PART_REQUEST_END, + 1, msg + 64); + + if (!ret) + ret = read_response(client, resp); + + if (ret > 0) { + /* End transactions work, we are good. */ + ssif_info->cmd8_works = true; + return; + } + + ret = start_multipart_test(client, msg, do_middle); + if (ret) { + dev_err(&client->dev, "Second multipart test failed.\n"); + goto out_no_multi_part; + } + + ret = i2c_smbus_write_block_data(client, + SSIF_IPMI_MULTI_PART_REQUEST_MIDDLE, + 0, msg + 64); + if (!ret) + ret = read_response(client, resp); + if (ret > 0) + /* Zero-size end parts work, use those. */ + return; + + /* Limit to 63 bytes and use a short middle command to mark the end. */ + if (ssif_info->max_xmit_msg_size > 63) + ssif_info->max_xmit_msg_size = 63; + return; + +out_no_multi_part: + ssif_info->max_xmit_msg_size = 32; + return; +} + +/* + * Global enables we care about. + */ +#define GLOBAL_ENABLES_MASK (IPMI_BMC_EVT_MSG_BUFF | IPMI_BMC_RCV_MSG_INTR | \ + IPMI_BMC_EVT_MSG_INTR) + +static void ssif_remove_dup(struct i2c_client *client) +{ + struct ssif_info *ssif_info = i2c_get_clientdata(client); + + ipmi_unregister_smi(ssif_info->intf); + kfree(ssif_info); +} + +static int ssif_add_infos(struct i2c_client *client) +{ + struct ssif_addr_info *info; + + info = kzalloc(sizeof(*info), GFP_KERNEL); + if (!info) + return -ENOMEM; + info->addr_src = SI_ACPI; + info->client = client; + info->adapter_name = kstrdup(client->adapter->name, GFP_KERNEL); + if (!info->adapter_name) { + kfree(info); + return -ENOMEM; + } + + info->binfo.addr = client->addr; + list_add_tail(&info->link, &ssif_infos); + return 0; +} + +/* + * Prefer ACPI over SMBIOS, if both are available. + * So if we get an ACPI interface and have already registered a SMBIOS + * interface at the same address, remove the SMBIOS and add the ACPI one. + */ +static int ssif_check_and_remove(struct i2c_client *client, + struct ssif_info *ssif_info) +{ + struct ssif_addr_info *info; + + list_for_each_entry(info, &ssif_infos, link) { + if (!info->client) + return 0; + if (!strcmp(info->adapter_name, client->adapter->name) && + info->binfo.addr == client->addr) { + if (info->addr_src == SI_ACPI) + return -EEXIST; + + if (ssif_info->addr_source == SI_ACPI && + info->addr_src == SI_SMBIOS) { + dev_info(&client->dev, + "Removing %s-specified SSIF interface in favor of ACPI\n", + ipmi_addr_src_to_str(info->addr_src)); + ssif_remove_dup(info->client); + return 0; + } + } + } + return 0; +} + +static int ssif_probe(struct i2c_client *client) +{ + unsigned char msg[3]; + unsigned char *resp; + struct ssif_info *ssif_info; + int rv = 0; + int len = 0; + int i; + u8 slave_addr = 0; + struct ssif_addr_info *addr_info = NULL; + + mutex_lock(&ssif_infos_mutex); + resp = kmalloc(IPMI_MAX_MSG_LENGTH, GFP_KERNEL); + if (!resp) { + mutex_unlock(&ssif_infos_mutex); + return -ENOMEM; + } + + ssif_info = kzalloc(sizeof(*ssif_info), GFP_KERNEL); + if (!ssif_info) { + kfree(resp); + mutex_unlock(&ssif_infos_mutex); + return -ENOMEM; + } + + if (!check_acpi(ssif_info, &client->dev)) { + addr_info = ssif_info_find(client->addr, client->adapter->name, + true); + if (!addr_info) { + /* Must have come in through sysfs. */ + ssif_info->addr_source = SI_HOTMOD; + } else { + ssif_info->addr_source = addr_info->addr_src; + ssif_info->ssif_debug = addr_info->debug; + ssif_info->addr_info = addr_info->addr_info; + addr_info->client = client; + slave_addr = addr_info->slave_addr; + } + } + + ssif_info->client = client; + i2c_set_clientdata(client, ssif_info); + + rv = ssif_check_and_remove(client, ssif_info); + /* If rv is 0 and addr source is not SI_ACPI, continue probing */ + if (!rv && ssif_info->addr_source == SI_ACPI) { + rv = ssif_add_infos(client); + if (rv) { + dev_err(&client->dev, "Out of memory!, exiting ..\n"); + goto out; + } + } else if (rv) { + dev_err(&client->dev, "Not probing, Interface already present\n"); + goto out; + } + + slave_addr = find_slave_address(client, slave_addr); + + dev_info(&client->dev, + "Trying %s-specified SSIF interface at i2c address 0x%x, adapter %s, slave address 0x%x\n", + ipmi_addr_src_to_str(ssif_info->addr_source), + client->addr, client->adapter->name, slave_addr); + + /* Now check for system interface capabilities */ + msg[0] = IPMI_NETFN_APP_REQUEST << 2; + msg[1] = IPMI_GET_SYSTEM_INTERFACE_CAPABILITIES_CMD; + msg[2] = 0; /* SSIF */ + rv = do_cmd(client, 3, msg, &len, resp); + if (!rv && (len >= 3) && (resp[2] == 0)) { + if (len < 7) { + if (ssif_dbg_probe) + dev_dbg(&ssif_info->client->dev, + "SSIF info too short: %d\n", len); + goto no_support; + } + + /* Got a good SSIF response, handle it. */ + ssif_info->max_xmit_msg_size = resp[5]; + ssif_info->max_recv_msg_size = resp[6]; + ssif_info->multi_support = (resp[4] >> 6) & 0x3; + ssif_info->supports_pec = (resp[4] >> 3) & 0x1; + + /* Sanitize the data */ + switch (ssif_info->multi_support) { + case SSIF_NO_MULTI: + if (ssif_info->max_xmit_msg_size > 32) + ssif_info->max_xmit_msg_size = 32; + if (ssif_info->max_recv_msg_size > 32) + ssif_info->max_recv_msg_size = 32; + break; + + case SSIF_MULTI_2_PART: + if (ssif_info->max_xmit_msg_size > 63) + ssif_info->max_xmit_msg_size = 63; + if (ssif_info->max_recv_msg_size > 62) + ssif_info->max_recv_msg_size = 62; + break; + + case SSIF_MULTI_n_PART: + /* We take whatever size given, but do some testing. */ + break; + + default: + /* Data is not sane, just give up. */ + goto no_support; + } + } else { + no_support: + /* Assume no multi-part or PEC support */ + dev_info(&ssif_info->client->dev, + "Error fetching SSIF: %d %d %2.2x, your system probably doesn't support this command so using defaults\n", + rv, len, resp[2]); + + ssif_info->max_xmit_msg_size = 32; + ssif_info->max_recv_msg_size = 32; + ssif_info->multi_support = SSIF_NO_MULTI; + ssif_info->supports_pec = 0; + } + + test_multipart_messages(client, ssif_info, resp); + + /* Make sure the NMI timeout is cleared. */ + msg[0] = IPMI_NETFN_APP_REQUEST << 2; + msg[1] = IPMI_CLEAR_MSG_FLAGS_CMD; + msg[2] = WDT_PRE_TIMEOUT_INT; + rv = do_cmd(client, 3, msg, &len, resp); + if (rv || (len < 3) || (resp[2] != 0)) + dev_warn(&ssif_info->client->dev, + "Unable to clear message flags: %d %d %2.2x\n", + rv, len, resp[2]); + + /* Attempt to enable the event buffer. */ + msg[0] = IPMI_NETFN_APP_REQUEST << 2; + msg[1] = IPMI_GET_BMC_GLOBAL_ENABLES_CMD; + rv = do_cmd(client, 2, msg, &len, resp); + if (rv || (len < 4) || (resp[2] != 0)) { + dev_warn(&ssif_info->client->dev, + "Error getting global enables: %d %d %2.2x\n", + rv, len, resp[2]); + rv = 0; /* Not fatal */ + goto found; + } + + ssif_info->global_enables = resp[3]; + + if (resp[3] & IPMI_BMC_EVT_MSG_BUFF) { + ssif_info->has_event_buffer = true; + /* buffer is already enabled, nothing to do. */ + goto found; + } + + msg[0] = IPMI_NETFN_APP_REQUEST << 2; + msg[1] = IPMI_SET_BMC_GLOBAL_ENABLES_CMD; + msg[2] = ssif_info->global_enables | IPMI_BMC_EVT_MSG_BUFF; + rv = do_cmd(client, 3, msg, &len, resp); + if (rv || (len < 2)) { + dev_warn(&ssif_info->client->dev, + "Error setting global enables: %d %d %2.2x\n", + rv, len, resp[2]); + rv = 0; /* Not fatal */ + goto found; + } + + if (resp[2] == 0) { + /* A successful return means the event buffer is supported. */ + ssif_info->has_event_buffer = true; + ssif_info->global_enables |= IPMI_BMC_EVT_MSG_BUFF; + } + + /* Some systems don't behave well if you enable alerts. */ + if (alerts_broken) + goto found; + + msg[0] = IPMI_NETFN_APP_REQUEST << 2; + msg[1] = IPMI_SET_BMC_GLOBAL_ENABLES_CMD; + msg[2] = ssif_info->global_enables | IPMI_BMC_RCV_MSG_INTR; + rv = do_cmd(client, 3, msg, &len, resp); + if (rv || (len < 2)) { + dev_warn(&ssif_info->client->dev, + "Error setting global enables: %d %d %2.2x\n", + rv, len, resp[2]); + rv = 0; /* Not fatal */ + goto found; + } + + if (resp[2] == 0) { + /* A successful return means the alert is supported. */ + ssif_info->supports_alert = true; + ssif_info->global_enables |= IPMI_BMC_RCV_MSG_INTR; + } + + found: + if (ssif_dbg_probe) { + dev_dbg(&ssif_info->client->dev, + "%s: i2c_probe found device at i2c address %x\n", + __func__, client->addr); + } + + spin_lock_init(&ssif_info->lock); + ssif_info->ssif_state = SSIF_IDLE; + timer_setup(&ssif_info->retry_timer, retry_timeout, 0); + timer_setup(&ssif_info->watch_timer, watch_timeout, 0); + + for (i = 0; i < SSIF_NUM_STATS; i++) + atomic_set(&ssif_info->stats[i], 0); + + if (ssif_info->supports_pec) + ssif_info->client->flags |= I2C_CLIENT_PEC; + + ssif_info->handlers.owner = THIS_MODULE; + ssif_info->handlers.start_processing = ssif_start_processing; + ssif_info->handlers.shutdown = shutdown_ssif; + ssif_info->handlers.get_smi_info = get_smi_info; + ssif_info->handlers.sender = sender; + ssif_info->handlers.request_events = request_events; + ssif_info->handlers.set_need_watch = ssif_set_need_watch; + + { + unsigned int thread_num; + + thread_num = ((i2c_adapter_id(ssif_info->client->adapter) + << 8) | + ssif_info->client->addr); + init_completion(&ssif_info->wake_thread); + ssif_info->thread = kthread_run(ipmi_ssif_thread, ssif_info, + "kssif%4.4x", thread_num); + if (IS_ERR(ssif_info->thread)) { + rv = PTR_ERR(ssif_info->thread); + dev_notice(&ssif_info->client->dev, + "Could not start kernel thread: error %d\n", + rv); + goto out; + } + } + + dev_set_drvdata(&ssif_info->client->dev, ssif_info); + rv = device_add_group(&ssif_info->client->dev, + &ipmi_ssif_dev_attr_group); + if (rv) { + dev_err(&ssif_info->client->dev, + "Unable to add device attributes: error %d\n", + rv); + goto out; + } + + rv = ipmi_register_smi(&ssif_info->handlers, + ssif_info, + &ssif_info->client->dev, + slave_addr); + if (rv) { + dev_err(&ssif_info->client->dev, + "Unable to register device: error %d\n", rv); + goto out_remove_attr; + } + + out: + if (rv) { + if (addr_info) + addr_info->client = NULL; + + dev_err(&ssif_info->client->dev, + "Unable to start IPMI SSIF: %d\n", rv); + i2c_set_clientdata(client, NULL); + kfree(ssif_info); + } + kfree(resp); + mutex_unlock(&ssif_infos_mutex); + return rv; + +out_remove_attr: + device_remove_group(&ssif_info->client->dev, &ipmi_ssif_dev_attr_group); + dev_set_drvdata(&ssif_info->client->dev, NULL); + goto out; +} + +static int new_ssif_client(int addr, char *adapter_name, + int debug, int slave_addr, + enum ipmi_addr_src addr_src, + struct device *dev) +{ + struct ssif_addr_info *addr_info; + int rv = 0; + + mutex_lock(&ssif_infos_mutex); + if (ssif_info_find(addr, adapter_name, false)) { + rv = -EEXIST; + goto out_unlock; + } + + addr_info = kzalloc(sizeof(*addr_info), GFP_KERNEL); + if (!addr_info) { + rv = -ENOMEM; + goto out_unlock; + } + + if (adapter_name) { + addr_info->adapter_name = kstrdup(adapter_name, GFP_KERNEL); + if (!addr_info->adapter_name) { + kfree(addr_info); + rv = -ENOMEM; + goto out_unlock; + } + } + + strncpy(addr_info->binfo.type, DEVICE_NAME, + sizeof(addr_info->binfo.type)); + addr_info->binfo.addr = addr; + addr_info->binfo.platform_data = addr_info; + addr_info->debug = debug; + addr_info->slave_addr = slave_addr; + addr_info->addr_src = addr_src; + addr_info->dev = dev; + + if (dev) + dev_set_drvdata(dev, addr_info); + + list_add_tail(&addr_info->link, &ssif_infos); + + /* Address list will get it */ + +out_unlock: + mutex_unlock(&ssif_infos_mutex); + return rv; +} + +static void free_ssif_clients(void) +{ + struct ssif_addr_info *info, *tmp; + + mutex_lock(&ssif_infos_mutex); + list_for_each_entry_safe(info, tmp, &ssif_infos, link) { + list_del(&info->link); + kfree(info->adapter_name); + kfree(info); + } + mutex_unlock(&ssif_infos_mutex); +} + +static unsigned short *ssif_address_list(void) +{ + struct ssif_addr_info *info; + unsigned int count = 0, i = 0; + unsigned short *address_list; + + list_for_each_entry(info, &ssif_infos, link) + count++; + + address_list = kcalloc(count + 1, sizeof(*address_list), + GFP_KERNEL); + if (!address_list) + return NULL; + + list_for_each_entry(info, &ssif_infos, link) { + unsigned short addr = info->binfo.addr; + int j; + + for (j = 0; j < i; j++) { + if (address_list[j] == addr) + /* Found a dup. */ + break; + } + if (j == i) /* Didn't find it in the list. */ + address_list[i++] = addr; + } + address_list[i] = I2C_CLIENT_END; + + return address_list; +} + +#ifdef CONFIG_ACPI +static const struct acpi_device_id ssif_acpi_match[] = { + { "IPI0001", 0 }, + { }, +}; +MODULE_DEVICE_TABLE(acpi, ssif_acpi_match); +#endif + +#ifdef CONFIG_DMI +static int dmi_ipmi_probe(struct platform_device *pdev) +{ + u8 slave_addr = 0; + u16 i2c_addr; + int rv; + + if (!ssif_trydmi) + return -ENODEV; + + rv = device_property_read_u16(&pdev->dev, "i2c-addr", &i2c_addr); + if (rv) { + dev_warn(&pdev->dev, "No i2c-addr property\n"); + return -ENODEV; + } + + rv = device_property_read_u8(&pdev->dev, "slave-addr", &slave_addr); + if (rv) + slave_addr = 0x20; + + return new_ssif_client(i2c_addr, NULL, 0, + slave_addr, SI_SMBIOS, &pdev->dev); +} +#else +static int dmi_ipmi_probe(struct platform_device *pdev) +{ + return -ENODEV; +} +#endif + +static const struct i2c_device_id ssif_id[] = { + { DEVICE_NAME, 0 }, + { } +}; +MODULE_DEVICE_TABLE(i2c, ssif_id); + +static struct i2c_driver ssif_i2c_driver = { + .class = I2C_CLASS_HWMON, + .driver = { + .name = DEVICE_NAME + }, + .probe = ssif_probe, + .remove = ssif_remove, + .alert = ssif_alert, + .id_table = ssif_id, + .detect = ssif_detect +}; + +static int ssif_platform_probe(struct platform_device *dev) +{ + return dmi_ipmi_probe(dev); +} + +static int ssif_platform_remove(struct platform_device *dev) +{ + struct ssif_addr_info *addr_info = dev_get_drvdata(&dev->dev); + + mutex_lock(&ssif_infos_mutex); + list_del(&addr_info->link); + kfree(addr_info); + mutex_unlock(&ssif_infos_mutex); + return 0; +} + +static const struct platform_device_id ssif_plat_ids[] = { + { "dmi-ipmi-ssif", 0 }, + { } +}; + +static struct platform_driver ipmi_driver = { + .driver = { + .name = DEVICE_NAME, + }, + .probe = ssif_platform_probe, + .remove = ssif_platform_remove, + .id_table = ssif_plat_ids +}; + +static int __init init_ipmi_ssif(void) +{ + int i; + int rv; + + if (initialized) + return 0; + + pr_info("IPMI SSIF Interface driver\n"); + + /* build list for i2c from addr list */ + for (i = 0; i < num_addrs; i++) { + rv = new_ssif_client(addr[i], adapter_name[i], + dbg[i], slave_addrs[i], + SI_HARDCODED, NULL); + if (rv) + pr_err("Couldn't add hardcoded device at addr 0x%x\n", + addr[i]); + } + + if (ssif_tryacpi) + ssif_i2c_driver.driver.acpi_match_table = + ACPI_PTR(ssif_acpi_match); + + if (ssif_trydmi) { + rv = platform_driver_register(&ipmi_driver); + if (rv) + pr_err("Unable to register driver: %d\n", rv); + else + platform_registered = true; + } + + ssif_i2c_driver.address_list = ssif_address_list(); + + rv = i2c_add_driver(&ssif_i2c_driver); + if (!rv) + initialized = true; + + return rv; +} +module_init(init_ipmi_ssif); + +static void __exit cleanup_ipmi_ssif(void) +{ + if (!initialized) + return; + + initialized = false; + + i2c_del_driver(&ssif_i2c_driver); + + kfree(ssif_i2c_driver.address_list); + + if (ssif_trydmi && platform_registered) + platform_driver_unregister(&ipmi_driver); + + free_ssif_clients(); +} +module_exit(cleanup_ipmi_ssif); + +MODULE_ALIAS("platform:dmi-ipmi-ssif"); +MODULE_AUTHOR("Todd C Davis <todd.c.davis@intel.com>, Corey Minyard <minyard@acm.org>"); +MODULE_DESCRIPTION("IPMI driver for management controllers on a SMBus"); +MODULE_LICENSE("GPL"); |