aha1542: rework locking

Remove aha1542_lock and use host_lock instead.
Remove interrupt and queuecommand function wrappers.
Remove locking from lowlevel _out and _in functions, they now can
onle be called (at runtime) with host_lock being held.
Remove ssleep(4) in aha1542_reset as we can't sleep while holding a spinlock.
It's useless anyway as wait_mask will wait until the controller is idle and
kernel waits for 10 seconds (HOST_RESET_SETTLE_TIME) after that.

Signed-off-by: Ondrej Zary <linux@rainbow-software.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: James Bottomley <JBottomley@Odin.com>

1 files changed, 34 insertions, 84 deletions

diff --git a/drivers/scsi/aha1542.c b/drivers/scsi/aha1542.c
index a19fcb02ff20..7b5d396deaa5 100644
--- a/drivers/scsi/aha1542.c
+++ b/drivers/scsi/aha1542.c
@@ -62,8 +62,6 @@ struct aha1542_hostdata {
         struct ccb ccb[AHA1542_MAILBOXES];
 };
 
-static DEFINE_SPINLOCK(aha1542_lock);
-
 static inline void aha1542_intr_reset(u16 base)
 {
         outb(IRST, CONTROL(base));
@@ -91,41 +89,25 @@ static inline bool wait_mask(u16 port, u8 mask, u8 allof, u8 noneof, int timeout
         return true;
 }
 
-/* This is a bit complicated, but we need to make sure that an interrupt
-   routine does not send something out while we are in the middle of this.
-   Fortunately, it is only at boot time that multi-byte messages
-   are ever sent. */
 static int aha1542_outb(unsigned int base, u8 val)
 {
-        unsigned long flags;
-
         while (1) {
                 if (!wait_mask(STATUS(base), CDF, 0, CDF, 0))
                         return 1;
-                spin_lock_irqsave(&aha1542_lock, flags);
-                if (inb(STATUS(base)) & CDF) {
-                        spin_unlock_irqrestore(&aha1542_lock, flags);
+                if (inb(STATUS(base)) & CDF)
                         continue;
-                }
                 outb(val, DATA(base));
-                spin_unlock_irqrestore(&aha1542_lock, flags);
                 return 0;
         }
 }
 
 static int aha1542_out(unsigned int base, u8 *buf, int len)
 {
-        unsigned long flags;
-
-        spin_lock_irqsave(&aha1542_lock, flags);
         while (len--) {
-                if (!wait_mask(STATUS(base), CDF, 0, CDF, 0)) {
-                        spin_unlock_irqrestore(&aha1542_lock, flags);
+                if (!wait_mask(STATUS(base), CDF, 0, CDF, 0))
                         return 1;
-                }
                 outb(*buf++, DATA(base));
         }
-        spin_unlock_irqrestore(&aha1542_lock, flags);
         if (!wait_mask(INTRFLAGS(base), INTRMASK, HACC, 0, 0))
                 return 1;
 
@@ -137,17 +119,11 @@ static int aha1542_out(unsigned int base, u8 *buf, int len)
 
 static int aha1542_in(unsigned int base, u8 *buf, int len, int timeout)
 {
-        unsigned long flags;
-
-        spin_lock_irqsave(&aha1542_lock, flags);
         while (len--) {
-                if (!wait_mask(STATUS(base), DF, DF, 0, timeout)) {
-                        spin_unlock_irqrestore(&aha1542_lock, flags);
+                if (!wait_mask(STATUS(base), DF, DF, 0, timeout))
                         return 1;
-                }
                 *buf++ = inb(DATA(base));
         }
-        spin_unlock_irqrestore(&aha1542_lock, flags);
         return 0;
 }
 
@@ -260,9 +236,9 @@ static int aha1542_test_port(struct Scsi_Host *sh)
         return 1;
 }
 
-/* A "high" level interrupt handler */
-static void aha1542_intr_handle(struct Scsi_Host *sh)
+static irqreturn_t aha1542_interrupt(int irq, void *dev_id)
 {
+        struct Scsi_Host *sh = dev_id;
         struct aha1542_hostdata *aha1542 = shost_priv(sh);
         void (*my_done)(struct scsi_cmnd *) = NULL;
         int errstatus, mbi, mbo, mbistatus;
@@ -292,7 +268,8 @@ static void aha1542_intr_handle(struct Scsi_Host *sh)
 #endif
         number_serviced = 0;
 
-        while (1 == 1) {
+        spin_lock_irqsave(sh->host_lock, flags);
+        while (1) {
                 flag = inb(INTRFLAGS(sh->io_port));
 
                 /* Check for unusual interrupts.  If any of these happen, we should
@@ -309,7 +286,6 @@ static void aha1542_intr_handle(struct Scsi_Host *sh)
                 }
                 aha1542_intr_reset(sh->io_port);
 
-                spin_lock_irqsave(&aha1542_lock, flags);
                 mbi = aha1542->aha1542_last_mbi_used + 1;
                 if (mbi >= 2 * AHA1542_MAILBOXES)
                         mbi = AHA1542_MAILBOXES;
@@ -323,18 +299,17 @@ static void aha1542_intr_handle(struct Scsi_Host *sh)
                 } while (mbi != aha1542->aha1542_last_mbi_used);
 
                 if (mb[mbi].status == 0) {
-                        spin_unlock_irqrestore(&aha1542_lock, flags);
+                        spin_unlock_irqrestore(sh->host_lock, flags);
                         /* Hmm, no mail.  Must have read it the last time around */
                         if (!number_serviced)
                                 shost_printk(KERN_WARNING, sh, "interrupt received, but no mail.\n");
-                        return;
+                        return IRQ_HANDLED;
                 };
 
                 mbo = (scsi2int(mb[mbi].ccbptr) - (isa_virt_to_bus(&ccb[0]))) / sizeof(struct ccb);
                 mbistatus = mb[mbi].status;
                 mb[mbi].status = 0;
                 aha1542->aha1542_last_mbi_used = mbi;
-                spin_unlock_irqrestore(&aha1542_lock, flags);
 
 #ifdef DEBUG
                 if (ccb[mbo].tarstat | ccb[mbo].hastat)
@@ -352,10 +327,11 @@ static void aha1542_intr_handle(struct Scsi_Host *sh)
                 tmp_cmd = aha1542->int_cmds[mbo];
 
                 if (!tmp_cmd || !tmp_cmd->scsi_done) {
+                        spin_unlock_irqrestore(sh->host_lock, flags);
                         shost_printk(KERN_WARNING, sh, "Unexpected interrupt\n");
                         shost_printk(KERN_WARNING, sh, "tarstat=%x, hastat=%x idlun=%x ccb#=%d\n", ccb[mbo].tarstat,
                                ccb[mbo].hastat, ccb[mbo].idlun, mbo);
-                        return;
+                        return IRQ_HANDLED;
                 }
                 my_done = tmp_cmd->scsi_done;
                 kfree(tmp_cmd->host_scribble);
@@ -394,21 +370,8 @@ static void aha1542_intr_handle(struct Scsi_Host *sh)
         };
 }
 
-/* A quick wrapper for do_aha1542_intr_handle to grab the spin lock */
-static irqreturn_t do_aha1542_intr_handle(int dummy, void *dev_id)
+static int aha1542_queuecommand(struct Scsi_Host *sh, struct scsi_cmnd *cmd)
 {
-        unsigned long flags;
-        struct Scsi_Host *sh = dev_id;
-
-        spin_lock_irqsave(sh->host_lock, flags);
-        aha1542_intr_handle(sh);
-        spin_unlock_irqrestore(sh->host_lock, flags);
-        return IRQ_HANDLED;
-}
-
-static int aha1542_queuecommand_lck(struct scsi_cmnd *cmd, void (*done) (struct scsi_cmnd *))
-{
-        struct Scsi_Host *sh = cmd->device->host;
         struct aha1542_hostdata *aha1542 = shost_priv(sh);
         u8 direction;
         u8 target = cmd->device->id;
@@ -422,7 +385,7 @@ static int aha1542_queuecommand_lck(struct scsi_cmnd *cmd, void (*done) (struct
         if (*cmd->cmnd == REQUEST_SENSE) {
                 /* Don't do the command - we have the sense data already */
                 cmd->result = 0;
-                done(cmd);
+                cmd->scsi_done(cmd);
                 return 0;
         }
 #ifdef DEBUG
@@ -440,7 +403,7 @@ static int aha1542_queuecommand_lck(struct scsi_cmnd *cmd, void (*done) (struct
         /* Use the outgoing mailboxes in a round-robin fashion, because this
            is how the host adapter will scan for them */
 
-        spin_lock_irqsave(&aha1542_lock, flags);
+        spin_lock_irqsave(sh->host_lock, flags);
         mbo = aha1542->aha1542_last_mbo_used + 1;
         if (mbo >= AHA1542_MAILBOXES)
                 mbo = 0;
@@ -460,10 +423,9 @@ static int aha1542_queuecommand_lck(struct scsi_cmnd *cmd, void (*done) (struct
                                            screwing with this cdb. */
 
         aha1542->aha1542_last_mbo_used = mbo;
-        spin_unlock_irqrestore(&aha1542_lock, flags);
 
 #ifdef DEBUG
-        shost_printk(KERN_DEBUG, sh, "Sending command (%d %p)...", mbo, done);
+        shost_printk(KERN_DEBUG, sh, "Sending command (%d %p)...", mbo, cmd->scsi_done);
 #endif
 
         any2scsi(mb[mbo].ccbptr, isa_virt_to_bus(&ccb[mbo]));   /* This gets trashed for some reason */
@@ -492,6 +454,7 @@ static int aha1542_queuecommand_lck(struct scsi_cmnd *cmd, void (*done) (struct
                 if (cptr == NULL) {
                         /* free the claimed mailbox slot */
                         aha1542->int_cmds[mbo] = NULL;
+                        spin_unlock_irqrestore(sh->host_lock, flags);
                         return SCSI_MLQUEUE_HOST_BUSY;
                 }
                 scsi_for_each_sg(cmd, sg, sg_count, i) {
@@ -518,23 +481,15 @@ static int aha1542_queuecommand_lck(struct scsi_cmnd *cmd, void (*done) (struct
 
 #ifdef DEBUG
         print_hex_dump_bytes("sending: ", DUMP_PREFIX_NONE, &ccb[mbo], sizeof(ccb[mbo]) - 10);
+        printk("aha1542_queuecommand: now waiting for interrupt ");
 #endif
-
-        if (done) {
-#ifdef DEBUG
-                printk("aha1542_queuecommand: now waiting for interrupt ");
-#endif
-                cmd->scsi_done = done;
-                mb[mbo].status = 1;
-                aha1542_outb(cmd->device->host->io_port, CMD_START_SCSI);
-        } else
-                printk("aha1542_queuecommand: done can't be NULL\n");
+        mb[mbo].status = 1;
+        aha1542_outb(cmd->device->host->io_port, CMD_START_SCSI);
+        spin_unlock_irqrestore(sh->host_lock, flags);
 
         return 0;
 }
 
-static DEF_SCSI_QCMD(aha1542_queuecommand)
-
 /* Initialize mailboxes */
 static void setup_mailboxes(struct Scsi_Host *sh)
 {
@@ -786,8 +741,7 @@ static struct Scsi_Host *aha1542_hw_init(struct scsi_host_template *tpnt, struct
 
         setup_mailboxes(sh);
 
-        if (request_irq(sh->irq, do_aha1542_intr_handle, 0,
-                                        "aha1542", sh)) {
+        if (request_irq(sh->irq, aha1542_interrupt, 0, "aha1542", sh)) {
                 shost_printk(KERN_ERR, sh, "Unable to allocate IRQ.\n");
                 goto unregister;
         }
@@ -841,7 +795,8 @@ static int aha1542_release(struct Scsi_Host *sh)
  */
 static int aha1542_dev_reset(struct scsi_cmnd *cmd)
 {
-        struct aha1542_hostdata *aha1542 = shost_priv(cmd->device->host);
+        struct Scsi_Host *sh = cmd->device->host;
+        struct aha1542_hostdata *aha1542 = shost_priv(sh);
         unsigned long flags;
         struct mailbox *mb = aha1542->mb;
         u8 target = cmd->device->id;
@@ -849,7 +804,7 @@ static int aha1542_dev_reset(struct scsi_cmnd *cmd)
         int mbo;
         struct ccb *ccb = aha1542->ccb;
 
-        spin_lock_irqsave(&aha1542_lock, flags);
+        spin_lock_irqsave(sh->host_lock, flags);
         mbo = aha1542->aha1542_last_mbo_used + 1;
         if (mbo >= AHA1542_MAILBOXES)
                 mbo = 0;
@@ -870,7 +825,6 @@ static int aha1542_dev_reset(struct scsi_cmnd *cmd)
                                            screwing with this cdb. */
 
         aha1542->aha1542_last_mbo_used = mbo;
-        spin_unlock_irqrestore(&aha1542_lock, flags);
 
         any2scsi(mb[mbo].ccbptr, isa_virt_to_bus(&ccb[mbo]));   /* This gets trashed for some reason */
 
@@ -887,7 +841,8 @@ static int aha1542_dev_reset(struct scsi_cmnd *cmd)
          * Now tell the 1542 to flush all pending commands for this 
          * target 
          */
-        aha1542_outb(cmd->device->host->io_port, CMD_START_SCSI);
+        aha1542_outb(sh->io_port, CMD_START_SCSI);
+        spin_unlock_irqrestore(sh->host_lock, flags);
 
         scmd_printk(KERN_WARNING, cmd,
                 "Trying device reset for target\n");
@@ -897,9 +852,12 @@ static int aha1542_dev_reset(struct scsi_cmnd *cmd)
 
 static int aha1542_reset(struct scsi_cmnd *cmd, u8 reset_cmd)
 {
-        struct aha1542_hostdata *aha1542 = shost_priv(cmd->device->host);
+        struct Scsi_Host *sh = cmd->device->host;
+        struct aha1542_hostdata *aha1542 = shost_priv(sh);
+        unsigned long flags;
         int i;
 
+        spin_lock_irqsave(sh->host_lock, flags);
         /* 
          * This does a scsi reset for all devices on the bus.
          * In principle, we could also reset the 1542 - should
@@ -908,27 +866,19 @@ static int aha1542_reset(struct scsi_cmnd *cmd, u8 reset_cmd)
          */
         outb(reset_cmd, CONTROL(cmd->device->host->io_port));
 
-        /*
-         * Wait for the thing to settle down a bit.  Unfortunately
-         * this is going to basically lock up the machine while we
-         * wait for this to complete.  To be 100% correct, we need to
-         * check for timeout, and if we are doing something like this
-         * we are pretty desperate anyways.
-         */
-        ssleep(4);
-        spin_lock_irq(cmd->device->host->host_lock);
-
         if (!wait_mask(STATUS(cmd->device->host->io_port),
              STATMASK, INIT | IDLE, STST | DIAGF | INVDCMD | DF | CDF, 0)) {
-                spin_unlock_irq(cmd->device->host->host_lock);
+                spin_unlock_irqrestore(sh->host_lock, flags);
                 return FAILED;
         }
+
         /*
          * We need to do this too before the 1542 can interact with
          * us again after host reset.
          */
         if (reset_cmd & HRST)
                 setup_mailboxes(cmd->device->host);
+
         /*
          * Now try to pick up the pieces.  For all pending commands,
          * free any internal data structures, and basically clear things
@@ -958,7 +908,7 @@ static int aha1542_reset(struct scsi_cmnd *cmd, u8 reset_cmd)
                 }
         }
 
-        spin_unlock_irq(cmd->device->host->host_lock);
+        spin_unlock_irqrestore(sh->host_lock, flags);
         return SUCCESS;
 }