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path: root/drivers/block/rsxx/cregs.c
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Diffstat (limited to 'drivers/block/rsxx/cregs.c')
-rw-r--r--drivers/block/rsxx/cregs.c743
1 files changed, 743 insertions, 0 deletions
diff --git a/drivers/block/rsxx/cregs.c b/drivers/block/rsxx/cregs.c
new file mode 100644
index 000000000000..a31fd727e804
--- /dev/null
+++ b/drivers/block/rsxx/cregs.c
@@ -0,0 +1,743 @@
+/*
+* 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 void copy_to_creg_data(struct rsxx_cardinfo *card,
+ int cnt8,
+ void *buf,
+ unsigned int stream)
+{
+ int i = 0;
+ u32 *data = buf;
+
+ 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));
+ }
+}
+
+
+static void copy_from_creg_data(struct rsxx_cardinfo *card,
+ int cnt8,
+ void *buf,
+ unsigned int stream)
+{
+ int i = 0;
+ u32 *data = buf;
+
+ 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));
+ }
+}
+
+static struct creg_cmd *pop_active_cmd(struct rsxx_cardinfo *card)
+{
+ struct creg_cmd *cmd;
+
+ /*
+ * Spin lock is needed because this can be called in atomic/interrupt
+ * context.
+ */
+ spin_lock_bh(&card->creg_ctrl.pop_lock);
+ cmd = card->creg_ctrl.active_cmd;
+ card->creg_ctrl.active_cmd = NULL;
+ spin_unlock_bh(&card->creg_ctrl.pop_lock);
+
+ return cmd;
+}
+
+static void creg_issue_cmd(struct rsxx_cardinfo *card, struct creg_cmd *cmd)
+{
+ iowrite32(cmd->addr, card->regmap + CREG_ADD);
+ iowrite32(cmd->cnt8, card->regmap + CREG_CNT);
+
+ if (cmd->op == CREG_OP_WRITE) {
+ if (cmd->buf)
+ copy_to_creg_data(card, cmd->cnt8,
+ cmd->buf, cmd->stream);
+ }
+
+ /* Data copy must complete before initiating the command. */
+ wmb();
+
+ /* 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;
+
+ mutex_lock(&card->creg_ctrl.lock);
+ list_add_tail(&cmd->list, &card->creg_ctrl.queue);
+ card->creg_ctrl.q_depth++;
+ creg_kick_queue(card);
+ mutex_unlock(&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;
+
+ cmd = pop_active_cmd(card);
+ 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.pop_lock);
+ card->creg_ctrl.active = 0;
+ creg_kick_queue(card);
+ spin_unlock(&card->creg_ctrl.pop_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++;
+
+ cmd = pop_active_cmd(card);
+ 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;
+ }
+
+ 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);
+
+ mutex_lock(&card->creg_ctrl.lock);
+ card->creg_ctrl.active = 0;
+ creg_kick_queue(card);
+ mutex_unlock(&card->creg_ctrl.lock);
+}
+
+static void creg_reset(struct rsxx_cardinfo *card)
+{
+ struct creg_cmd *cmd = NULL;
+ struct creg_cmd *tmp;
+ unsigned long flags;
+
+ 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 */
+ mutex_lock(&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;
+ }
+ mutex_unlock(&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 = (struct creg_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;
+
+ INIT_COMPLETION(cmd_done);
+ 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;
+
+ 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) {
+ 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 = (void *)((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 to string(up to count bytes) point to by src
+ * (including the terminating '\0' character) to dest. 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;
+
+ 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;
+}
+
+/*------------ Initialization & Setup --------------*/
+int rsxx_creg_setup(struct rsxx_cardinfo *card)
+{
+ card->creg_ctrl.active_cmd = NULL;
+
+ INIT_WORK(&card->creg_ctrl.done_work, creg_cmd_done);
+ mutex_init(&card->creg_ctrl.reset_lock);
+ INIT_LIST_HEAD(&card->creg_ctrl.queue);
+ mutex_init(&card->creg_ctrl.lock);
+ spin_lock_init(&card->creg_ctrl.pop_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 */
+ mutex_lock(&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);
+ }
+ mutex_unlock(&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);
+}