diff options
Diffstat (limited to 'drivers/block/rsxx/cregs.c')
| -rw-r--r-- | drivers/block/rsxx/cregs.c | 804 |
1 files changed, 804 insertions, 0 deletions
diff --git a/drivers/block/rsxx/cregs.c b/drivers/block/rsxx/cregs.c new file mode 100644 index 000000000..926dce9c4 --- /dev/null +++ b/drivers/block/rsxx/cregs.c @@ -0,0 +1,804 @@ +/* +* Filename: cregs.c +* +* +* Authors: Joshua Morris <josh.h.morris@us.ibm.com> +* Philip Kelleher <pjk1939@linux.vnet.ibm.com> +* +* (C) Copyright 2013 IBM Corporation +* +* This program is free software; you can redistribute it and/or +* modify it under the terms of the GNU General Public License as +* published by the Free Software Foundation; either version 2 of the +* License, or (at your option) any later version. +* +* This program is distributed in the hope that it will be useful, but +* WITHOUT ANY WARRANTY; without even the implied warranty of +* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU +* General Public License for more details. +* +* You should have received a copy of the GNU General Public License +* along with this program; if not, write to the Free Software Foundation, +* Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA +*/ + +#include <linux/completion.h> +#include <linux/slab.h> + +#include "rsxx_priv.h" + +#define CREG_TIMEOUT_MSEC 10000 + +typedef void (*creg_cmd_cb)(struct rsxx_cardinfo *card, + struct creg_cmd *cmd, + int st); + +struct creg_cmd { + struct list_head list; + creg_cmd_cb cb; + void *cb_private; + unsigned int op; + unsigned int addr; + int cnt8; + void *buf; + unsigned int stream; + unsigned int status; +}; + +static struct kmem_cache *creg_cmd_pool; + + +/*------------ Private Functions --------------*/ + +#if defined(__LITTLE_ENDIAN) +#define LITTLE_ENDIAN 1 +#elif defined(__BIG_ENDIAN) +#define LITTLE_ENDIAN 0 +#else +#error Unknown endianess!!! Aborting... +#endif + +static int copy_to_creg_data(struct rsxx_cardinfo *card, + int cnt8, + void *buf, + unsigned int stream) +{ + int i = 0; + u32 *data = buf; + + if (unlikely(card->eeh_state)) + return -EIO; + + for (i = 0; cnt8 > 0; i++, cnt8 -= 4) { + /* + * Firmware implementation makes it necessary to byte swap on + * little endian processors. + */ + if (LITTLE_ENDIAN && stream) + iowrite32be(data[i], card->regmap + CREG_DATA(i)); + else + iowrite32(data[i], card->regmap + CREG_DATA(i)); + } + + return 0; +} + + +static int copy_from_creg_data(struct rsxx_cardinfo *card, + int cnt8, + void *buf, + unsigned int stream) +{ + int i = 0; + u32 *data = buf; + + if (unlikely(card->eeh_state)) + return -EIO; + + for (i = 0; cnt8 > 0; i++, cnt8 -= 4) { + /* + * Firmware implementation makes it necessary to byte swap on + * little endian processors. + */ + if (LITTLE_ENDIAN && stream) + data[i] = ioread32be(card->regmap + CREG_DATA(i)); + else + data[i] = ioread32(card->regmap + CREG_DATA(i)); + } + + return 0; +} + +static void creg_issue_cmd(struct rsxx_cardinfo *card, struct creg_cmd *cmd) +{ + int st; + + if (unlikely(card->eeh_state)) + return; + + iowrite32(cmd->addr, card->regmap + CREG_ADD); + iowrite32(cmd->cnt8, card->regmap + CREG_CNT); + + if (cmd->op == CREG_OP_WRITE) { + if (cmd->buf) { + st = copy_to_creg_data(card, cmd->cnt8, + cmd->buf, cmd->stream); + if (st) + return; + } + } + + if (unlikely(card->eeh_state)) + return; + + /* Setting the valid bit will kick off the command. */ + iowrite32(cmd->op, card->regmap + CREG_CMD); +} + +static void creg_kick_queue(struct rsxx_cardinfo *card) +{ + if (card->creg_ctrl.active || list_empty(&card->creg_ctrl.queue)) + return; + + card->creg_ctrl.active = 1; + card->creg_ctrl.active_cmd = list_first_entry(&card->creg_ctrl.queue, + struct creg_cmd, list); + list_del(&card->creg_ctrl.active_cmd->list); + card->creg_ctrl.q_depth--; + + /* + * We have to set the timer before we push the new command. Otherwise, + * we could create a race condition that would occur if the timer + * was not canceled, and expired after the new command was pushed, + * but before the command was issued to hardware. + */ + mod_timer(&card->creg_ctrl.cmd_timer, + jiffies + msecs_to_jiffies(CREG_TIMEOUT_MSEC)); + + creg_issue_cmd(card, card->creg_ctrl.active_cmd); +} + +static int creg_queue_cmd(struct rsxx_cardinfo *card, + unsigned int op, + unsigned int addr, + unsigned int cnt8, + void *buf, + int stream, + creg_cmd_cb callback, + void *cb_private) +{ + struct creg_cmd *cmd; + + /* Don't queue stuff up if we're halted. */ + if (unlikely(card->halt)) + return -EINVAL; + + if (card->creg_ctrl.reset) + return -EAGAIN; + + if (cnt8 > MAX_CREG_DATA8) + return -EINVAL; + + cmd = kmem_cache_alloc(creg_cmd_pool, GFP_KERNEL); + if (!cmd) + return -ENOMEM; + + INIT_LIST_HEAD(&cmd->list); + + cmd->op = op; + cmd->addr = addr; + cmd->cnt8 = cnt8; + cmd->buf = buf; + cmd->stream = stream; + cmd->cb = callback; + cmd->cb_private = cb_private; + cmd->status = 0; + + spin_lock_bh(&card->creg_ctrl.lock); + list_add_tail(&cmd->list, &card->creg_ctrl.queue); + card->creg_ctrl.q_depth++; + creg_kick_queue(card); + spin_unlock_bh(&card->creg_ctrl.lock); + + return 0; +} + +static void creg_cmd_timed_out(unsigned long data) +{ + struct rsxx_cardinfo *card = (struct rsxx_cardinfo *) data; + struct creg_cmd *cmd; + + spin_lock(&card->creg_ctrl.lock); + cmd = card->creg_ctrl.active_cmd; + card->creg_ctrl.active_cmd = NULL; + spin_unlock(&card->creg_ctrl.lock); + + if (cmd == NULL) { + card->creg_ctrl.creg_stats.creg_timeout++; + dev_warn(CARD_TO_DEV(card), + "No active command associated with timeout!\n"); + return; + } + + if (cmd->cb) + cmd->cb(card, cmd, -ETIMEDOUT); + + kmem_cache_free(creg_cmd_pool, cmd); + + + spin_lock(&card->creg_ctrl.lock); + card->creg_ctrl.active = 0; + creg_kick_queue(card); + spin_unlock(&card->creg_ctrl.lock); +} + + +static void creg_cmd_done(struct work_struct *work) +{ + struct rsxx_cardinfo *card; + struct creg_cmd *cmd; + int st = 0; + + card = container_of(work, struct rsxx_cardinfo, + creg_ctrl.done_work); + + /* + * The timer could not be cancelled for some reason, + * race to pop the active command. + */ + if (del_timer_sync(&card->creg_ctrl.cmd_timer) == 0) + card->creg_ctrl.creg_stats.failed_cancel_timer++; + + spin_lock_bh(&card->creg_ctrl.lock); + cmd = card->creg_ctrl.active_cmd; + card->creg_ctrl.active_cmd = NULL; + spin_unlock_bh(&card->creg_ctrl.lock); + + if (cmd == NULL) { + dev_err(CARD_TO_DEV(card), + "Spurious creg interrupt!\n"); + return; + } + + card->creg_ctrl.creg_stats.stat = ioread32(card->regmap + CREG_STAT); + cmd->status = card->creg_ctrl.creg_stats.stat; + if ((cmd->status & CREG_STAT_STATUS_MASK) == 0) { + dev_err(CARD_TO_DEV(card), + "Invalid status on creg command\n"); + /* + * At this point we're probably reading garbage from HW. Don't + * do anything else that could mess up the system and let + * the sync function return an error. + */ + st = -EIO; + goto creg_done; + } else if (cmd->status & CREG_STAT_ERROR) { + st = -EIO; + } + + if ((cmd->op == CREG_OP_READ)) { + unsigned int cnt8 = ioread32(card->regmap + CREG_CNT); + + /* Paranoid Sanity Checks */ + if (!cmd->buf) { + dev_err(CARD_TO_DEV(card), + "Buffer not given for read.\n"); + st = -EIO; + goto creg_done; + } + if (cnt8 != cmd->cnt8) { + dev_err(CARD_TO_DEV(card), + "count mismatch\n"); + st = -EIO; + goto creg_done; + } + + st = copy_from_creg_data(card, cnt8, cmd->buf, cmd->stream); + } + +creg_done: + if (cmd->cb) + cmd->cb(card, cmd, st); + + kmem_cache_free(creg_cmd_pool, cmd); + + spin_lock_bh(&card->creg_ctrl.lock); + card->creg_ctrl.active = 0; + creg_kick_queue(card); + spin_unlock_bh(&card->creg_ctrl.lock); +} + +static void creg_reset(struct rsxx_cardinfo *card) +{ + struct creg_cmd *cmd = NULL; + struct creg_cmd *tmp; + unsigned long flags; + + /* + * mutex_trylock is used here because if reset_lock is taken then a + * reset is already happening. So, we can just go ahead and return. + */ + if (!mutex_trylock(&card->creg_ctrl.reset_lock)) + return; + + card->creg_ctrl.reset = 1; + spin_lock_irqsave(&card->irq_lock, flags); + rsxx_disable_ier_and_isr(card, CR_INTR_CREG | CR_INTR_EVENT); + spin_unlock_irqrestore(&card->irq_lock, flags); + + dev_warn(CARD_TO_DEV(card), + "Resetting creg interface for recovery\n"); + + /* Cancel outstanding commands */ + spin_lock_bh(&card->creg_ctrl.lock); + list_for_each_entry_safe(cmd, tmp, &card->creg_ctrl.queue, list) { + list_del(&cmd->list); + card->creg_ctrl.q_depth--; + if (cmd->cb) + cmd->cb(card, cmd, -ECANCELED); + kmem_cache_free(creg_cmd_pool, cmd); + } + + cmd = card->creg_ctrl.active_cmd; + card->creg_ctrl.active_cmd = NULL; + if (cmd) { + if (timer_pending(&card->creg_ctrl.cmd_timer)) + del_timer_sync(&card->creg_ctrl.cmd_timer); + + if (cmd->cb) + cmd->cb(card, cmd, -ECANCELED); + kmem_cache_free(creg_cmd_pool, cmd); + + card->creg_ctrl.active = 0; + } + spin_unlock_bh(&card->creg_ctrl.lock); + + card->creg_ctrl.reset = 0; + spin_lock_irqsave(&card->irq_lock, flags); + rsxx_enable_ier_and_isr(card, CR_INTR_CREG | CR_INTR_EVENT); + spin_unlock_irqrestore(&card->irq_lock, flags); + + mutex_unlock(&card->creg_ctrl.reset_lock); +} + +/* Used for synchronous accesses */ +struct creg_completion { + struct completion *cmd_done; + int st; + u32 creg_status; +}; + +static void creg_cmd_done_cb(struct rsxx_cardinfo *card, + struct creg_cmd *cmd, + int st) +{ + struct creg_completion *cmd_completion; + + cmd_completion = cmd->cb_private; + BUG_ON(!cmd_completion); + + cmd_completion->st = st; + cmd_completion->creg_status = cmd->status; + complete(cmd_completion->cmd_done); +} + +static int __issue_creg_rw(struct rsxx_cardinfo *card, + unsigned int op, + unsigned int addr, + unsigned int cnt8, + void *buf, + int stream, + unsigned int *hw_stat) +{ + DECLARE_COMPLETION_ONSTACK(cmd_done); + struct creg_completion completion; + unsigned long timeout; + int st; + + completion.cmd_done = &cmd_done; + completion.st = 0; + completion.creg_status = 0; + + st = creg_queue_cmd(card, op, addr, cnt8, buf, stream, creg_cmd_done_cb, + &completion); + if (st) + return st; + + /* + * This timeout is necessary for unresponsive hardware. The additional + * 20 seconds to used to guarantee that each cregs requests has time to + * complete. + */ + timeout = msecs_to_jiffies(CREG_TIMEOUT_MSEC * + card->creg_ctrl.q_depth + 20000); + + /* + * The creg interface is guaranteed to complete. It has a timeout + * mechanism that will kick in if hardware does not respond. + */ + st = wait_for_completion_timeout(completion.cmd_done, timeout); + if (st == 0) { + /* + * This is really bad, because the kernel timer did not + * expire and notify us of a timeout! + */ + dev_crit(CARD_TO_DEV(card), + "cregs timer failed\n"); + creg_reset(card); + return -EIO; + } + + *hw_stat = completion.creg_status; + + if (completion.st) { + /* + * This read is needed to verify that there has not been any + * extreme errors that might have occurred, i.e. EEH. The + * function iowrite32 will not detect EEH errors, so it is + * necessary that we recover if such an error is the reason + * for the timeout. This is a dummy read. + */ + ioread32(card->regmap + SCRATCH); + + dev_warn(CARD_TO_DEV(card), + "creg command failed(%d x%08x)\n", + completion.st, addr); + return completion.st; + } + + return 0; +} + +static int issue_creg_rw(struct rsxx_cardinfo *card, + u32 addr, + unsigned int size8, + void *data, + int stream, + int read) +{ + unsigned int hw_stat; + unsigned int xfer; + unsigned int op; + int st; + + op = read ? CREG_OP_READ : CREG_OP_WRITE; + + do { + xfer = min_t(unsigned int, size8, MAX_CREG_DATA8); + + st = __issue_creg_rw(card, op, addr, xfer, + data, stream, &hw_stat); + if (st) + return st; + + data = (char *)data + xfer; + addr += xfer; + size8 -= xfer; + } while (size8); + + return 0; +} + +/* ---------------------------- Public API ---------------------------------- */ +int rsxx_creg_write(struct rsxx_cardinfo *card, + u32 addr, + unsigned int size8, + void *data, + int byte_stream) +{ + return issue_creg_rw(card, addr, size8, data, byte_stream, 0); +} + +int rsxx_creg_read(struct rsxx_cardinfo *card, + u32 addr, + unsigned int size8, + void *data, + int byte_stream) +{ + return issue_creg_rw(card, addr, size8, data, byte_stream, 1); +} + +int rsxx_get_card_state(struct rsxx_cardinfo *card, unsigned int *state) +{ + return rsxx_creg_read(card, CREG_ADD_CARD_STATE, + sizeof(*state), state, 0); +} + +int rsxx_get_card_size8(struct rsxx_cardinfo *card, u64 *size8) +{ + unsigned int size; + int st; + + st = rsxx_creg_read(card, CREG_ADD_CARD_SIZE, + sizeof(size), &size, 0); + if (st) + return st; + + *size8 = (u64)size * RSXX_HW_BLK_SIZE; + return 0; +} + +int rsxx_get_num_targets(struct rsxx_cardinfo *card, + unsigned int *n_targets) +{ + return rsxx_creg_read(card, CREG_ADD_NUM_TARGETS, + sizeof(*n_targets), n_targets, 0); +} + +int rsxx_get_card_capabilities(struct rsxx_cardinfo *card, + u32 *capabilities) +{ + return rsxx_creg_read(card, CREG_ADD_CAPABILITIES, + sizeof(*capabilities), capabilities, 0); +} + +int rsxx_issue_card_cmd(struct rsxx_cardinfo *card, u32 cmd) +{ + return rsxx_creg_write(card, CREG_ADD_CARD_CMD, + sizeof(cmd), &cmd, 0); +} + + +/*----------------- HW Log Functions -------------------*/ +static void hw_log_msg(struct rsxx_cardinfo *card, const char *str, int len) +{ + static char level; + + /* + * New messages start with "<#>", where # is the log level. Messages + * that extend past the log buffer will use the previous level + */ + if ((len > 3) && (str[0] == '<') && (str[2] == '>')) { + level = str[1]; + str += 3; /* Skip past the log level. */ + len -= 3; + } + + switch (level) { + case '0': + dev_emerg(CARD_TO_DEV(card), "HW: %.*s", len, str); + break; + case '1': + dev_alert(CARD_TO_DEV(card), "HW: %.*s", len, str); + break; + case '2': + dev_crit(CARD_TO_DEV(card), "HW: %.*s", len, str); + break; + case '3': + dev_err(CARD_TO_DEV(card), "HW: %.*s", len, str); + break; + case '4': + dev_warn(CARD_TO_DEV(card), "HW: %.*s", len, str); + break; + case '5': + dev_notice(CARD_TO_DEV(card), "HW: %.*s", len, str); + break; + case '6': + dev_info(CARD_TO_DEV(card), "HW: %.*s", len, str); + break; + case '7': + dev_dbg(CARD_TO_DEV(card), "HW: %.*s", len, str); + break; + default: + dev_info(CARD_TO_DEV(card), "HW: %.*s", len, str); + break; + } +} + +/* + * The substrncpy function copies the src string (which includes the + * terminating '\0' character), up to the count into the dest pointer. + * Returns the number of bytes copied to dest. + */ +static int substrncpy(char *dest, const char *src, int count) +{ + int max_cnt = count; + + while (count) { + count--; + *dest = *src; + if (*dest == '\0') + break; + src++; + dest++; + } + return max_cnt - count; +} + + +static void read_hw_log_done(struct rsxx_cardinfo *card, + struct creg_cmd *cmd, + int st) +{ + char *buf; + char *log_str; + int cnt; + int len; + int off; + + buf = cmd->buf; + off = 0; + + /* Failed getting the log message */ + if (st) + return; + + while (off < cmd->cnt8) { + log_str = &card->log.buf[card->log.buf_len]; + cnt = min(cmd->cnt8 - off, LOG_BUF_SIZE8 - card->log.buf_len); + len = substrncpy(log_str, &buf[off], cnt); + + off += len; + card->log.buf_len += len; + + /* + * Flush the log if we've hit the end of a message or if we've + * run out of buffer space. + */ + if ((log_str[len - 1] == '\0') || + (card->log.buf_len == LOG_BUF_SIZE8)) { + if (card->log.buf_len != 1) /* Don't log blank lines. */ + hw_log_msg(card, card->log.buf, + card->log.buf_len); + card->log.buf_len = 0; + } + + } + + if (cmd->status & CREG_STAT_LOG_PENDING) + rsxx_read_hw_log(card); +} + +int rsxx_read_hw_log(struct rsxx_cardinfo *card) +{ + int st; + + st = creg_queue_cmd(card, CREG_OP_READ, CREG_ADD_LOG, + sizeof(card->log.tmp), card->log.tmp, + 1, read_hw_log_done, NULL); + if (st) + dev_err(CARD_TO_DEV(card), + "Failed getting log text\n"); + + return st; +} + +/*-------------- IOCTL REG Access ------------------*/ +static int issue_reg_cmd(struct rsxx_cardinfo *card, + struct rsxx_reg_access *cmd, + int read) +{ + unsigned int op = read ? CREG_OP_READ : CREG_OP_WRITE; + + return __issue_creg_rw(card, op, cmd->addr, cmd->cnt, cmd->data, + cmd->stream, &cmd->stat); +} + +int rsxx_reg_access(struct rsxx_cardinfo *card, + struct rsxx_reg_access __user *ucmd, + int read) +{ + struct rsxx_reg_access cmd; + int st; + + st = copy_from_user(&cmd, ucmd, sizeof(cmd)); + if (st) + return -EFAULT; + + if (cmd.cnt > RSXX_MAX_REG_CNT) + return -EFAULT; + + st = issue_reg_cmd(card, &cmd, read); + if (st) + return st; + + st = put_user(cmd.stat, &ucmd->stat); + if (st) + return -EFAULT; + + if (read) { + st = copy_to_user(ucmd->data, cmd.data, cmd.cnt); + if (st) + return -EFAULT; + } + + return 0; +} + +void rsxx_eeh_save_issued_creg(struct rsxx_cardinfo *card) +{ + struct creg_cmd *cmd = NULL; + + cmd = card->creg_ctrl.active_cmd; + card->creg_ctrl.active_cmd = NULL; + + if (cmd) { + del_timer_sync(&card->creg_ctrl.cmd_timer); + + spin_lock_bh(&card->creg_ctrl.lock); + list_add(&cmd->list, &card->creg_ctrl.queue); + card->creg_ctrl.q_depth++; + card->creg_ctrl.active = 0; + spin_unlock_bh(&card->creg_ctrl.lock); + } +} + +void rsxx_kick_creg_queue(struct rsxx_cardinfo *card) +{ + spin_lock_bh(&card->creg_ctrl.lock); + if (!list_empty(&card->creg_ctrl.queue)) + creg_kick_queue(card); + spin_unlock_bh(&card->creg_ctrl.lock); +} + +/*------------ Initialization & Setup --------------*/ +int rsxx_creg_setup(struct rsxx_cardinfo *card) +{ + card->creg_ctrl.active_cmd = NULL; + + card->creg_ctrl.creg_wq = + create_singlethread_workqueue(DRIVER_NAME"_creg"); + if (!card->creg_ctrl.creg_wq) + return -ENOMEM; + + INIT_WORK(&card->creg_ctrl.done_work, creg_cmd_done); + mutex_init(&card->creg_ctrl.reset_lock); + INIT_LIST_HEAD(&card->creg_ctrl.queue); + spin_lock_init(&card->creg_ctrl.lock); + setup_timer(&card->creg_ctrl.cmd_timer, creg_cmd_timed_out, + (unsigned long) card); + + return 0; +} + +void rsxx_creg_destroy(struct rsxx_cardinfo *card) +{ + struct creg_cmd *cmd; + struct creg_cmd *tmp; + int cnt = 0; + + /* Cancel outstanding commands */ + spin_lock_bh(&card->creg_ctrl.lock); + list_for_each_entry_safe(cmd, tmp, &card->creg_ctrl.queue, list) { + list_del(&cmd->list); + if (cmd->cb) + cmd->cb(card, cmd, -ECANCELED); + kmem_cache_free(creg_cmd_pool, cmd); + cnt++; + } + + if (cnt) + dev_info(CARD_TO_DEV(card), + "Canceled %d queue creg commands\n", cnt); + + cmd = card->creg_ctrl.active_cmd; + card->creg_ctrl.active_cmd = NULL; + if (cmd) { + if (timer_pending(&card->creg_ctrl.cmd_timer)) + del_timer_sync(&card->creg_ctrl.cmd_timer); + + if (cmd->cb) + cmd->cb(card, cmd, -ECANCELED); + dev_info(CARD_TO_DEV(card), + "Canceled active creg command\n"); + kmem_cache_free(creg_cmd_pool, cmd); + } + spin_unlock_bh(&card->creg_ctrl.lock); + + cancel_work_sync(&card->creg_ctrl.done_work); +} + + +int rsxx_creg_init(void) +{ + creg_cmd_pool = KMEM_CACHE(creg_cmd, SLAB_HWCACHE_ALIGN); + if (!creg_cmd_pool) + return -ENOMEM; + + return 0; +} + +void rsxx_creg_cleanup(void) +{ + kmem_cache_destroy(creg_cmd_pool); +} |