cfi_cmdset_0001: factorize code to wait for flash status

This allows for much better abstraction and separation of the XIP and
non-XIP cases with their own specific implementations.  This fixes the
case where a timeout was tripped on in the XIP case by the code that
was meant for the non-XIP case only.

This also makes for a nice code reduction.

Signed-off-by: Nicolas Pitre <nico@cam.org>
CC: "Alexey, Korolev" <alexey.korolev@intel.com>
Signed-off-by: David Woodhouse <dwmw2@infradead.org>

1 files changed, 157 insertions, 264 deletions

diff --git a/drivers/mtd/chips/cfi_cmdset_0001.c b/drivers/mtd/chips/cfi_cmdset_0001.c
index ab3888f5e464..d0d5e521b564 100644
--- a/drivers/mtd/chips/cfi_cmdset_0001.c
+++ b/drivers/mtd/chips/cfi_cmdset_0001.c
@@ -399,7 +399,7 @@ struct mtd_info *cfi_cmdset_0001(struct map_info *map, int primary)
         for (i=0; i< cfi->numchips; i++) {
                 cfi->chips[i].word_write_time = 1<<cfi->cfiq->WordWriteTimeoutTyp;
                 cfi->chips[i].buffer_write_time = 1<<cfi->cfiq->BufWriteTimeoutTyp;
-                cfi->chips[i].erase_time = 1<<cfi->cfiq->BlockEraseTimeoutTyp;
+                cfi->chips[i].erase_time = 1000<<cfi->cfiq->BlockEraseTimeoutTyp;
                 cfi->chips[i].ref_point_counter = 0;
                 init_waitqueue_head(&(cfi->chips[i].wq));
         }
@@ -894,26 +894,33 @@ static void __xipram xip_enable(struct map_info *map, struct flchip *chip,
 
 /*
  * When a delay is required for the flash operation to complete, the
- * xip_udelay() function is polling for both the given timeout and pending
- * (but still masked) hardware interrupts.  Whenever there is an interrupt
- * pending then the flash erase or write operation is suspended, array mode
- * restored and interrupts unmasked.  Task scheduling might also happen at that
- * point.  The CPU eventually returns from the interrupt or the call to
- * schedule() and the suspended flash operation is resumed for the remaining
- * of the delay period.
+ * xip_wait_for_operation() function is polling for both the given timeout
+ * and pending (but still masked) hardware interrupts.  Whenever there is an
+ * interrupt pending then the flash erase or write operation is suspended,
+ * array mode restored and interrupts unmasked.  Task scheduling might also
+ * happen at that point.  The CPU eventually returns from the interrupt or
+ * the call to schedule() and the suspended flash operation is resumed for
+ * the remaining of the delay period.
  *
  * Warning: this function _will_ fool interrupt latency tracing tools.
  */
 
-static void __xipram xip_udelay(struct map_info *map, struct flchip *chip,
-                                unsigned long adr, int usec)
+static int __xipram xip_wait_for_operation(
+                struct map_info *map, struct flchip *chip,
+                unsigned long adr, int *chip_op_time )
 {
         struct cfi_private *cfi = map->fldrv_priv;
         struct cfi_pri_intelext *cfip = cfi->cmdset_priv;
         map_word status, OK = CMD(0x80);
-        unsigned long suspended, start = xip_currtime();
+        unsigned long usec, suspended, start, done;
         flstate_t oldstate, newstate;
 
+        start = xip_currtime();
+        usec = *chip_op_time * 8;
+        if (usec == 0)
+                usec = 500000;
+        done = 0;
+
         do {
                 cpu_relax();
                 if (xip_irqpending() && cfip &&
@@ -930,9 +937,9 @@ static void __xipram xip_udelay(struct map_info *map, struct flchip *chip,
                          * we resume the whole thing at once).  Yes, it
                          * can happen!
                          */
+                        usec -= done;
                         map_write(map, CMD(0xb0), adr);
                         map_write(map, CMD(0x70), adr);
-                        usec -= xip_elapsed_since(start);
                         suspended = xip_currtime();
                         do {
                                 if (xip_elapsed_since(suspended) > 100000) {
@@ -942,7 +949,7 @@ static void __xipram xip_udelay(struct map_info *map, struct flchip *chip,
                                          * This is a critical error but there
                                          * is not much we can do here.
                                          */
-                                        return;
+                                        return -EIO;
                                 }
                                 status = map_read(map, adr);
                         } while (!map_word_andequal(map, status, OK, OK));
@@ -1002,65 +1009,107 @@ static void __xipram xip_udelay(struct map_info *map, struct flchip *chip,
                         xip_cpu_idle();
                 }
                 status = map_read(map, adr);
+                done = xip_elapsed_since(start);
         } while (!map_word_andequal(map, status, OK, OK)
-                 && xip_elapsed_since(start) < usec);
-}
+                 && done < usec);
 
-#define UDELAY(map, chip, adr, usec)  xip_udelay(map, chip, adr, usec)
+        return (done >= usec) ? -ETIME : 0;
+}
 
 /*
  * The INVALIDATE_CACHED_RANGE() macro is normally used in parallel while
  * the flash is actively programming or erasing since we have to poll for
  * the operation to complete anyway.  We can't do that in a generic way with
  * a XIP setup so do it before the actual flash operation in this case
- * and stub it out from INVALIDATE_CACHE_UDELAY.
+ * and stub it out from INVAL_CACHE_AND_WAIT.
  */
 #define XIP_INVAL_CACHED_RANGE(map, from, size)  \
         INVALIDATE_CACHED_RANGE(map, from, size)
 
-#define INVALIDATE_CACHE_UDELAY(map, chip, cmd_adr, adr, len, usec)  \
-        UDELAY(map, chip, cmd_adr, usec)
-
-/*
- * Extra notes:
- *
- * Activating this XIP support changes the way the code works a bit.  For
- * example the code to suspend the current process when concurrent access
- * happens is never executed because xip_udelay() will always return with the
- * same chip state as it was entered with.  This is why there is no care for
- * the presence of add_wait_queue() or schedule() calls from within a couple
- * xip_disable()'d  areas of code, like in do_erase_oneblock for example.
- * The queueing and scheduling are always happening within xip_udelay().
- *
- * Similarly, get_chip() and put_chip() just happen to always be executed
- * with chip->state set to FL_READY (or FL_XIP_WHILE_*) where flash state
- * is in array mode, therefore never executing many cases therein and not
- * causing any problem with XIP.
- */
+#define INVAL_CACHE_AND_WAIT(map, chip, cmd_adr, inval_adr, inval_len, p_usec) \
+        xip_wait_for_operation(map, chip, cmd_adr, p_usec)
 
 #else
 
 #define xip_disable(map, chip, adr)
 #define xip_enable(map, chip, adr)
 #define XIP_INVAL_CACHED_RANGE(x...)
+#define INVAL_CACHE_AND_WAIT inval_cache_and_wait_for_operation
+
+static int inval_cache_and_wait_for_operation(
+                struct map_info *map, struct flchip *chip,
+                unsigned long cmd_adr, unsigned long inval_adr, int inval_len,
+                int *chip_op_time )
+{
+        struct cfi_private *cfi = map->fldrv_priv;
+        map_word status, status_OK = CMD(0x80);
+        int z, chip_state = chip->state;
+        unsigned long timeo;
+
+        spin_unlock(chip->mutex);
+        if (inval_len)
+                INVALIDATE_CACHED_RANGE(map, inval_adr, inval_len);
+        if (*chip_op_time)
+                cfi_udelay(*chip_op_time);
+        spin_lock(chip->mutex);
+
+        timeo = *chip_op_time * 8 * HZ / 1000000;
+        if (timeo < HZ/2)
+                timeo = HZ/2;
+        timeo += jiffies;
+
+        z = 0;
+        for (;;) {
+                if (chip->state != chip_state) {
+                        /* Someone's suspended the operation: sleep */
+                        DECLARE_WAITQUEUE(wait, current);
+
+                        set_current_state(TASK_UNINTERRUPTIBLE);
+                        add_wait_queue(&chip->wq, &wait);
+                        spin_unlock(chip->mutex);
+                        schedule();
+                        remove_wait_queue(&chip->wq, &wait);
+                        timeo = jiffies + (HZ / 2); /* FIXME */
+                        spin_lock(chip->mutex);
+                        continue;
+                }
+
+                status = map_read(map, cmd_adr);
+                if (map_word_andequal(map, status, status_OK, status_OK))
+                        break;
 
-#define UDELAY(map, chip, adr, usec)  \
-do {  \
-        spin_unlock(chip->mutex);  \
-        cfi_udelay(usec);  \
-        spin_lock(chip->mutex);  \
-} while (0)
-
-#define INVALIDATE_CACHE_UDELAY(map, chip, cmd_adr, adr, len, usec)  \
-do {  \
-        spin_unlock(chip->mutex);  \
-        INVALIDATE_CACHED_RANGE(map, adr, len);  \
-        cfi_udelay(usec);  \
-        spin_lock(chip->mutex);  \
-} while (0)
+                /* OK Still waiting */
+                if (time_after(jiffies, timeo)) {
+                        map_write(map, CMD(0x70), cmd_adr);
+                        chip->state = FL_STATUS;
+                        return -ETIME;
+                }
+
+                /* Latency issues. Drop the lock, wait a while and retry */
+                z++;
+                spin_unlock(chip->mutex);
+                cfi_udelay(1);
+                spin_lock(chip->mutex);
+        }
+
+        if (!z) {
+                if (!--(*chip_op_time))
+                        *chip_op_time = 1;
+        } else if (z > 1)
+                ++(*chip_op_time);
+
+        /* Done and happy. */
+        chip->state = FL_STATUS;
+        return 0;
+}
 
 #endif
 
+#define WAIT_TIMEOUT(map, chip, adr, udelay) \
+        ({ int __udelay = (udelay); \
+           INVAL_CACHE_AND_WAIT(map, chip, adr, 0, 0, &__udelay); })
+
+
 static int do_point_onechip (struct map_info *map, struct flchip *chip, loff_t adr, size_t len)
 {
         unsigned long cmd_addr;
@@ -1250,14 +1299,11 @@ static int __xipram do_write_oneword(struct map_info *map, struct flchip *chip,
                                      unsigned long adr, map_word datum, int mode)
 {
         struct cfi_private *cfi = map->fldrv_priv;
-        map_word status, status_OK, write_cmd;
-        unsigned long timeo;
-        int z, ret=0;
+        map_word status, write_cmd;
+        int ret=0;
 
         adr += chip->start;
 
-        /* Let's determine those according to the interleave only once */
-        status_OK = CMD(0x80);
         switch (mode) {
         case FL_WRITING:
                 write_cmd = (cfi->cfiq->P_ID != 0x0200) ? CMD(0x40) : CMD(0x41);
@@ -1283,57 +1329,17 @@ static int __xipram do_write_oneword(struct map_info *map, struct flchip *chip,
         map_write(map, datum, adr);
         chip->state = mode;
 
-        INVALIDATE_CACHE_UDELAY(map, chip, adr,
-                                adr, map_bankwidth(map),
-                                chip->word_write_time);
-
-        timeo = jiffies + (HZ/2);
-        z = 0;
-        for (;;) {
-                if (chip->state != mode) {
-                        /* Someone's suspended the write. Sleep */
-                        DECLARE_WAITQUEUE(wait, current);
-
-                        set_current_state(TASK_UNINTERRUPTIBLE);
-                        add_wait_queue(&chip->wq, &wait);
-                        spin_unlock(chip->mutex);
-                        schedule();
-                        remove_wait_queue(&chip->wq, &wait);
-                        timeo = jiffies + (HZ / 2); /* FIXME */
-                        spin_lock(chip->mutex);
-                        continue;
-                }
-
-                status = map_read(map, adr);
-                if (map_word_andequal(map, status, status_OK, status_OK))
-                        break;
-
-                /* OK Still waiting */
-                if (time_after(jiffies, timeo)) {
-                        map_write(map, CMD(0x70), adr);
-                        chip->state = FL_STATUS;
-                        xip_enable(map, chip, adr);
-                        printk(KERN_ERR "%s: word write error (status timeout)\n", map->name);
-                        ret = -EIO;
-                        goto out;
-                }
-
-                /* Latency issues. Drop the lock, wait a while and retry */
-                z++;
-                UDELAY(map, chip, adr, 1);
-        }
-        if (!z) {
-                chip->word_write_time--;
-                if (!chip->word_write_time)
-                        chip->word_write_time = 1;
+        ret = INVAL_CACHE_AND_WAIT(map, chip, adr,
+                                   adr, map_bankwidth(map),
+                                   &chip->word_write_time);
+        if (ret) {
+                xip_enable(map, chip, adr);
+                printk(KERN_ERR "%s: word write error (status timeout)\n", map->name);
+                goto out;
         }
-        if (z > 1)
-                chip->word_write_time++;
-
-        /* Done and happy. */
-        chip->state = FL_STATUS;
 
         /* check for errors */
+        status = map_read(map, adr);
         if (map_word_bitsset(map, status, CMD(0x1a))) {
                 unsigned long chipstatus = MERGESTATUS(status);
 
@@ -1450,9 +1456,9 @@ static int __xipram do_write_buffer(struct map_info *map, struct flchip *chip,
                                     unsigned long *pvec_seek, int len)
 {
         struct cfi_private *cfi = map->fldrv_priv;
-        map_word status, status_OK, write_cmd, datum;
-        unsigned long cmd_adr, timeo;
-        int wbufsize, z, ret=0, word_gap, words;
+        map_word status, write_cmd, datum;
+        unsigned long cmd_adr;
+        int ret, wbufsize, word_gap, words;
         const struct kvec *vec;
         unsigned long vec_seek;
 
@@ -1461,7 +1467,6 @@ static int __xipram do_write_buffer(struct map_info *map, struct flchip *chip,
         cmd_adr = adr & ~(wbufsize-1);
 
         /* Let's determine this according to the interleave only once */
-        status_OK = CMD(0x80);
         write_cmd = (cfi->cfiq->P_ID != 0x0200) ? CMD(0xe8) : CMD(0xe9);
 
         spin_lock(chip->mutex);
@@ -1493,32 +1498,20 @@ static int __xipram do_write_buffer(struct map_info *map, struct flchip *chip,
         }
 
         chip->state = FL_WRITING_TO_BUFFER;
-
-        z = 0;
-        for (;;) {
-                map_write(map, write_cmd, cmd_adr);
-
+        map_write(map, write_cmd, cmd_adr);
+        ret = WAIT_TIMEOUT(map, chip, cmd_adr, 0);
+        if (ret) {
+                /* Argh. Not ready for write to buffer */
+                map_word Xstatus = map_read(map, cmd_adr);
+                map_write(map, CMD(0x70), cmd_adr);
+                chip->state = FL_STATUS;
                 status = map_read(map, cmd_adr);
-                if (map_word_andequal(map, status, status_OK, status_OK))
-                        break;
-
-                UDELAY(map, chip, cmd_adr, 1);
-
-                if (++z > 20) {
-                        /* Argh. Not ready for write to buffer */
-                        map_word Xstatus;
-                        map_write(map, CMD(0x70), cmd_adr);
-                        chip->state = FL_STATUS;
-                        Xstatus = map_read(map, cmd_adr);
-                        /* Odd. Clear status bits */
-                        map_write(map, CMD(0x50), cmd_adr);
-                        map_write(map, CMD(0x70), cmd_adr);
-                        xip_enable(map, chip, cmd_adr);
-                        printk(KERN_ERR "%s: Chip not ready for buffer write. status = %lx, Xstatus = %lx\n",
-                               map->name, status.x[0], Xstatus.x[0]);
-                        ret = -EIO;
-                        goto out;
-                }
+                map_write(map, CMD(0x50), cmd_adr);
+                map_write(map, CMD(0x70), cmd_adr);
+                xip_enable(map, chip, cmd_adr);
+                printk(KERN_ERR "%s: Chip not ready for buffer write. Xstatus = %lx, status = %lx\n",
+                                map->name, Xstatus.x[0], status.x[0]);
+                goto out;
         }
 
         /* Figure out the number of words to write */
@@ -1573,56 +1566,19 @@ static int __xipram do_write_buffer(struct map_info *map, struct flchip *chip,
         map_write(map, CMD(0xd0), cmd_adr);
         chip->state = FL_WRITING;
 
-        INVALIDATE_CACHE_UDELAY(map, chip, cmd_adr,
-                                adr, len,
-                                chip->buffer_write_time);
-
-        timeo = jiffies + (HZ/2);
-        z = 0;
-        for (;;) {
-                if (chip->state != FL_WRITING) {
-                        /* Someone's suspended the write. Sleep */
-                        DECLARE_WAITQUEUE(wait, current);
-                        set_current_state(TASK_UNINTERRUPTIBLE);
-                        add_wait_queue(&chip->wq, &wait);
-                        spin_unlock(chip->mutex);
-                        schedule();
-                        remove_wait_queue(&chip->wq, &wait);
-                        timeo = jiffies + (HZ / 2); /* FIXME */
-                        spin_lock(chip->mutex);
-                        continue;
-                }
-
-                status = map_read(map, cmd_adr);
-                if (map_word_andequal(map, status, status_OK, status_OK))
-                        break;
-
-                /* OK Still waiting */
-                if (time_after(jiffies, timeo)) {
-                        map_write(map, CMD(0x70), cmd_adr);
-                        chip->state = FL_STATUS;
-                        xip_enable(map, chip, cmd_adr);
-                        printk(KERN_ERR "%s: buffer write error (status timeout)\n", map->name);
-                        ret = -EIO;
-                        goto out;
-                }
-
-                /* Latency issues. Drop the lock, wait a while and retry */
-                z++;
-                UDELAY(map, chip, cmd_adr, 1);
-        }
-        if (!z) {
-                chip->buffer_write_time--;
-                if (!chip->buffer_write_time)
-                        chip->buffer_write_time = 1;
+        ret = INVAL_CACHE_AND_WAIT(map, chip, cmd_adr,
+                                   adr, len,
+                                   &chip->buffer_write_time);
+        if (ret) {
+                map_write(map, CMD(0x70), cmd_adr);
+                chip->state = FL_STATUS;
+                xip_enable(map, chip, cmd_adr);
+                printk(KERN_ERR "%s: buffer write error (status timeout)\n", map->name);
+                goto out;
         }
-        if (z > 1)
-                chip->buffer_write_time++;
-
-        /* Done and happy. */
-        chip->state = FL_STATUS;
 
         /* check for errors */
+        status = map_read(map, cmd_adr);
         if (map_word_bitsset(map, status, CMD(0x1a))) {
                 unsigned long chipstatus = MERGESTATUS(status);
 
@@ -1718,17 +1674,12 @@ static int __xipram do_erase_oneblock(struct map_info *map, struct flchip *chip,
                                       unsigned long adr, int len, void *thunk)
 {
         struct cfi_private *cfi = map->fldrv_priv;
-        map_word status, status_OK;
-        unsigned long timeo;
+        map_word status;
         int retries = 3;
-        DECLARE_WAITQUEUE(wait, current);
-        int ret = 0;
+        int ret;
 
         adr += chip->start;
 
-        /* Let's determine this according to the interleave only once */
-        status_OK = CMD(0x80);
-
  retry:
         spin_lock(chip->mutex);
         ret = get_chip(map, chip, adr, FL_ERASING);
@@ -1750,48 +1701,15 @@ static int __xipram do_erase_oneblock(struct map_info *map, struct flchip *chip,
         chip->state = FL_ERASING;
         chip->erase_suspended = 0;
 
-        INVALIDATE_CACHE_UDELAY(map, chip, adr,
-                                adr, len,
-                                chip->erase_time*1000/2);
-
-        /* FIXME. Use a timer to check this, and return immediately. */
-        /* Once the state machine's known to be working I'll do that */
-
-        timeo = jiffies + (HZ*20);
-        for (;;) {
-                if (chip->state != FL_ERASING) {
-                        /* Someone's suspended the erase. Sleep */
-                        set_current_state(TASK_UNINTERRUPTIBLE);
-                        add_wait_queue(&chip->wq, &wait);
-                        spin_unlock(chip->mutex);
-                        schedule();
-                        remove_wait_queue(&chip->wq, &wait);
-                        spin_lock(chip->mutex);
-                        continue;
-                }
-                if (chip->erase_suspended) {
-                        /* This erase was suspended and resumed.
-                           Adjust the timeout */
-                        timeo = jiffies + (HZ*20); /* FIXME */
-                        chip->erase_suspended = 0;
-                }
-
-                status = map_read(map, adr);
-                if (map_word_andequal(map, status, status_OK, status_OK))
-                        break;
-
-                /* OK Still waiting */
-                if (time_after(jiffies, timeo)) {
-                        map_write(map, CMD(0x70), adr);
-                        chip->state = FL_STATUS;
-                        xip_enable(map, chip, adr);
-                        printk(KERN_ERR "%s: block erase error: (status timeout)\n", map->name);
-                        ret = -EIO;
-                        goto out;
-                }
-
-                /* Latency issues. Drop the lock, wait a while and retry */
-                UDELAY(map, chip, adr, 1000000/HZ);
+        ret = INVAL_CACHE_AND_WAIT(map, chip, adr,
+                                   adr, len,
+                                   &chip->erase_time);
+        if (ret) {
+                map_write(map, CMD(0x70), adr);
+                chip->state = FL_STATUS;
+                xip_enable(map, chip, adr);
+                printk(KERN_ERR "%s: block erase error: (status timeout)\n", map->name);
+                goto out;
         }
 
         /* We've broken this before. It doesn't hurt to be safe */
@@ -1820,7 +1738,6 @@ static int __xipram do_erase_oneblock(struct map_info *map, struct flchip *chip,
                         ret = -EIO;
                 } else if (chipstatus & 0x20 && retries--) {
                         printk(KERN_DEBUG "block erase failed at 0x%08lx: status 0x%lx. Retrying...\n", adr, chipstatus);
-                        timeo = jiffies + HZ;
                         put_chip(map, chip, adr);
                         spin_unlock(chip->mutex);
                         goto retry;
@@ -1926,15 +1843,11 @@ static int __xipram do_xxlock_oneblock(struct map_info *map, struct flchip *chip
 {
         struct cfi_private *cfi = map->fldrv_priv;
         struct cfi_pri_intelext *extp = cfi->cmdset_priv;
-        map_word status, status_OK;
-        unsigned long timeo = jiffies + HZ;
+        int udelay;
         int ret;
 
         adr += chip->start;
 
-        /* Let's determine this according to the interleave only once */
-        status_OK = CMD(0x80);
-
         spin_lock(chip->mutex);
         ret = get_chip(map, chip, adr, FL_LOCKING);
         if (ret) {
@@ -1959,41 +1872,21 @@ static int __xipram do_xxlock_oneblock(struct map_info *map, struct flchip *chip
          * If Instant Individual Block Locking supported then no need
          * to delay.
          */
+        udelay = (!extp || !(extp->FeatureSupport & (1 << 5))) ? 1000000/HZ : 0;
 
-        if (!extp || !(extp->FeatureSupport & (1 << 5)))
-                UDELAY(map, chip, adr, 1000000/HZ);
-
-        /* FIXME. Use a timer to check this, and return immediately. */
-        /* Once the state machine's known to be working I'll do that */
-
-        timeo = jiffies + (HZ*20);
-        for (;;) {
-
-                status = map_read(map, adr);
-                if (map_word_andequal(map, status, status_OK, status_OK))
-                        break;
-
-                /* OK Still waiting */
-                if (time_after(jiffies, timeo)) {
-                        map_write(map, CMD(0x70), adr);
-                        chip->state = FL_STATUS;
-                        xip_enable(map, chip, adr);
-                        printk(KERN_ERR "%s: block unlock error: (status timeout)\n", map->name);
-                        put_chip(map, chip, adr);
-                        spin_unlock(chip->mutex);
-                        return -EIO;
-                }
-
-                /* Latency issues. Drop the lock, wait a while and retry */
-                UDELAY(map, chip, adr, 1);
+        ret = WAIT_TIMEOUT(map, chip, adr, udelay);
+        if (ret) {
+                map_write(map, CMD(0x70), adr);
+                chip->state = FL_STATUS;
+                xip_enable(map, chip, adr);
+                printk(KERN_ERR "%s: block unlock error: (status timeout)\n", map->name);
+                goto out;
         }
 
-        /* Done and happy. */
-        chip->state = FL_STATUS;
         xip_enable(map, chip, adr);
-        put_chip(map, chip, adr);
+out:    put_chip(map, chip, adr);
         spin_unlock(chip->mutex);
-        return 0;
+        return ret;
 }
 
 static int cfi_intelext_lock(struct mtd_info *mtd, loff_t ofs, size_t len)