Hi Alan,
do you still have time to look at NCR5380 occasionally? I recently
stumbled over the driver and have a few updates for 2.6:
- use schedule_delayed_work() instead of the global timer for the
coroutines
- use dev_id field in the isr instead of searching the global list
of hosts (g_NCR5380 had to be updated to pass in that one for
this change)
- use spinlocks even in the non-interrupt driven case, with SMP
and PREEMPT that's needed these days
- update the big comments to reflect reality
Unfortunately I don't any hardware to test, so if you could give this
a spin..
--- 1.23/drivers/scsi/NCR5380.c Sun Sep 28 02:38:22 2003
+++ edited/drivers/scsi/NCR5380.c Wed Nov 5 10:44:43 2003
@@ -113,32 +113,18 @@
/*
* Design
- * Issues :
*
- * The other Linux SCSI drivers were written when Linux was Intel PC-only,
- * and specifically for each board rather than each chip. This makes their
- * adaptation to platforms like the Mac (Some of which use NCR5380's)
- * more difficult than it has to be.
- *
- * Also, many of the SCSI drivers were written before the command queuing
- * routines were implemented, meaning their implementations of queued
- * commands were hacked on rather than designed in from the start.
- *
- * When I designed the Linux SCSI drivers I figured that
- * while having two different SCSI boards in a system might be useful
- * for debugging things, two of the same type wouldn't be used.
- * Well, I was wrong and a number of users have mailed me about running
- * multiple high-performance SCSI boards in a server.
- *
- * Finally, when I get questions from users, I have no idea what
- * revision of my driver they are running.
- *
- * This driver attempts to address these problems :
* This is a generic 5380 driver. To use it on a different platform,
* one simply writes appropriate system specific macros (ie, data
* transfer - some PC's will use the I/O bus, 68K's must use
* memory mapped) and drops this file in their 'C' wrapper.
*
+ * (Note from hch: unfortunately it was not enough for the different
+ * m68k folks and instead of improving this driver they copied it
+ * and hacked it up for their needs. As a consequence they lost
+ * most updates to this driver, sigh. Maybe someone will actually
+ * fixup their all the drivers to use a common core..)
+ *
* As far as command queueing, two queues are maintained for
* each 5380 in the system - commands that haven't been issued yet,
* and commands that are currently executing. This means that an
@@ -148,17 +134,6 @@
* allowing multiple commands to propagate all the way to a SCSI-II device
* while a command is already executing.
*
- * To solve the multiple-boards-in-the-same-system problem,
- * there is a separate instance structure for each instance
- * of a 5380 in the system. So, multiple NCR5380 drivers will
- * be able to coexist with appropriate changes to the high level
- * SCSI code.
- *
- * A NCR5380_PUBLIC_REVISION macro is provided, with the release
- * number (updated for each public release) printed by the
- * NCR5380_print_options command, which should be called from the
- * wrapper detect function, so that I know what release of the driver
- * users are using.
*
* Issues specific to the NCR5380 :
*
@@ -183,11 +158,10 @@
* Architecture :
*
* At the heart of the design is a coroutine, NCR5380_main,
- * which is started when not running by the interrupt handler,
- * timer, and queue command function. It attempts to establish
- * I_T_L or I_T_L_Q nexuses by removing the commands from the
- * issue queue and calling NCR5380_select() if a nexus
- * is not established.
+ * which is started from a workqueue for each NCR5380 host in the
+ * system. It attempts to establish I_T_L or I_T_L_Q nexuses by
+ * removing the commands from the issue queue and calling
+ * NCR5380_select() if a nexus is not established.
*
* Once a nexus is established, the NCR5380_information_transfer()
* phase goes through the various phases as instructed by the target.
@@ -289,33 +263,14 @@
* NCR5380_pwrite(instance, src, count)
* NCR5380_pread(instance, dst, count);
*
- * If nothing specific to this implementation needs doing (ie, with external
- * hardware), you must also define
- *
- * NCR5380_queue_command
- * NCR5380_reset
- * NCR5380_abort
- * NCR5380_proc_info
- *
- * to be the global entry points into the specific driver, ie
- * #define NCR5380_queue_command t128_queue_command.
- *
- * If this is not done, the routines will be defined as static functions
- * with the NCR5380* names and the user must provide a globally
- * accessible wrapper function.
- *
* The generic driver is initialized by calling NCR5380_init(instance),
* after setting the appropriate host specific fields and ID. If the
* driver wishes to autoprobe for an IRQ line, the NCR5380_probe_irq(instance,
- * possible) function may be used. Before the specific driver initialization
- * code finishes, NCR5380_print_options should be called.
+ * possible) function may be used.
*/
static int do_abort(struct Scsi_Host *host);
static void do_reset(struct Scsi_Host *host);
-static struct NCR5380_hostdata *first_host = NULL;
-static struct NCR5380_hostdata *last_host = NULL;
-static struct timer_list usleep_timer;
/*
* initialize_SCp - init the scsi pointer field
@@ -533,9 +488,6 @@
#define USLEEP_WAITLONG USLEEP_SLEEP
#endif
-static struct Scsi_Host *expires_first = NULL;
-static spinlock_t timer_lock; /* Guards expires list */
-
/*
* Function : int should_disconnect (unsigned char cmd)
*
@@ -578,93 +530,12 @@
}
}
-/*
- * Assumes instance->time_expires has been set in higher level code.
- * We should move to a timer per host
- *
- * Locks: Takes the timer queue lock
- */
-
-static int NCR5380_set_timer(struct Scsi_Host *instance)
+static void NCR5380_set_timer(struct NCR5380_hostdata *hostdata, unsigned long
timeout)
{
- struct Scsi_Host *tmp, **prev;
- unsigned long flags;
-
- if (((struct NCR5380_hostdata *) (instance->hostdata))->next_timer) {
- return -1;
- }
-
- spin_lock_irqsave(&timer_lock, flags);
- for (prev = &expires_first, tmp = expires_first; tmp; prev = &(((struct
NCR5380_hostdata *) tmp->hostdata)->next_timer), tmp = ((struct
NCR5380_hostdata *) tmp->hostdata)->next_timer)
- if (((struct NCR5380_hostdata *)
instance->hostdata)->time_expires < ((struct NCR5380_hostdata *)
tmp->hostdata)->time_expires)
- break;
-
- ((struct NCR5380_hostdata *) instance->hostdata)->next_timer = tmp;
- *prev = instance;
-
- mod_timer(&usleep_timer, ((struct NCR5380_hostdata *)
expires_first->hostdata)->time_expires);
-
- spin_unlock_irqrestore(&timer_lock, flags);
- return 0;
+ hostdata->time_expires = jiffies + timeout;
+ schedule_delayed_work(&hostdata->coroutine, hostdata->time_expires);
}
-/**
- * NCR5380_timer_fn - handle polled timeouts
- * @unused: unused
- *
- * Walk the list of controllers, find which controllers have exceeded
- * their expiry timeout and then schedule the processing co-routine to
- * do the real work.
- *
- * Doing something about unwanted reentrancy here might be useful
- *
- * Locks: disables irqs, takes and frees the timer lock
- */
-
-static void NCR5380_timer_fn(unsigned long unused)
-{
- struct Scsi_Host *instance;
- struct NCR5380_hostdata *hostdata;
- unsigned long flags;
-
- spin_lock_irqsave(&timer_lock, flags);
- for (; expires_first && time_before_eq(((struct NCR5380_hostdata *)
expires_first->hostdata)->time_expires, jiffies);)
- {
- hostdata = (struct NCR5380_hostdata *) expires_first->hostdata;
- schedule_work(&hostdata->coroutine);
- instance = hostdata->next_timer;
- hostdata->next_timer = NULL;
- hostdata->time_expires = 0;
- expires_first = instance;
- }
-
- del_timer(&usleep_timer);
- if (expires_first) {
- usleep_timer.expires = ((struct NCR5380_hostdata *)
expires_first->hostdata)->time_expires;
- add_timer(&usleep_timer);
- }
- spin_unlock_irqrestore(&timer_lock, flags);
-}
-
-/**
- * NCR5380_all_init - global setup
- *
- * Set up the global values and timers needed by the NCR5380 driver
- */
-
-static inline void NCR5380_all_init(void)
-{
- static int done = 0;
- if (!done) {
- dprintk(NDEBUG_INIT, ("scsi : NCR5380_all_init()\n"));
- done = 1;
- init_timer(&usleep_timer);
- spin_lock_init(&timer_lock);
- usleep_timer.function = NCR5380_timer_fn;
- }
-}
-
-
static int probe_irq __initdata = 0;
/**
@@ -984,7 +855,6 @@
#endif
NCR5380_setup(instance);
- NCR5380_all_init();
hostdata->aborted = 0;
hostdata->id_mask = 1 << instance->this_id;
@@ -1021,15 +891,6 @@
else
hostdata->flags = FLAG_CHECK_LAST_BYTE_SENT | flags;
- hostdata->next = NULL;
-
- if (!first_host)
- first_host = hostdata;
- else
- last_host->next = hostdata;
-
- last_host = hostdata;
-
hostdata->host = instance;
hostdata->time_expires = 0;
hostdata->next_timer = NULL;
@@ -1184,8 +1045,8 @@
static void NCR5380_main(void *p)
{
struct NCR5380_hostdata *hostdata = p;
+ struct Scsi_Host *instance = hostdata->host;
Scsi_Cmnd *tmp, *prev;
- struct Scsi_Host *instance;
int done;
unsigned long flags = 0;
@@ -1200,14 +1061,8 @@
*
* this should prevent any race conditions.
*/
-
- instance = hostdata->host;
-
- if(instance->irq != SCSI_IRQ_NONE)
- spin_lock_irqsave(instance->host_lock, flags);
-
+ spin_lock_irqsave(instance->host_lock, flags);
do {
- /* Lock held here */
done = 1;
if (!hostdata->connected && !hostdata->selecting) {
dprintk(NDEBUG_MAIN, ("scsi%d : not connected\n",
instance->host_no));
@@ -1286,8 +1141,7 @@
LIST(tmp, hostdata->issue_queue);
tmp->host_scribble = (unsigned char *)
hostdata->issue_queue;
hostdata->issue_queue = tmp;
- hostdata->time_expires = jiffies +
USLEEP_WAITLONG;
- NCR5380_set_timer(instance);
+ NCR5380_set_timer(hostdata, USLEEP_WAITLONG);
}
} /* if hostdata->selecting */
if (hostdata->connected
@@ -1304,8 +1158,7 @@
break;
} while (!done);
- if(instance->irq != SCSI_IRQ_NONE)
- spin_unlock_irqrestore(instance->host_lock, flags);
+ spin_unlock_irqrestore(instance->host_lock, flags);
}
#ifndef DONT_USE_INTR
@@ -1326,81 +1179,70 @@
static irqreturn_t NCR5380_intr(int irq, void *dev_id, struct pt_regs *regs)
{
NCR5380_local_declare();
- struct Scsi_Host *instance;
+ struct Scsi_Host *instance = dev_id;
int done;
unsigned char basr;
struct NCR5380_hostdata *hostdata;
- int handled = 0;
dprintk(NDEBUG_INTR, ("scsi : NCR5380 irq %d triggered\n", irq));
do {
done = 1;
- /* The instance list is constant while the driver is
- loaded */
- for (hostdata = first_host; hostdata != NULL; hostdata =
hostdata->next)
- {
- instance = hostdata->host;
- if (instance->irq == irq) {
- handled = 1;
- spin_lock_irq(instance->host_lock);
- /* Look for pending interrupts */
- NCR5380_setup(instance);
- basr = NCR5380_read(BUS_AND_STATUS_REG);
- /* XXX dispatch to appropriate routine if found
and done=0 */
- if (basr & BASR_IRQ) {
- NCR5380_dprint(NDEBUG_INTR, instance);
- if ((NCR5380_read(STATUS_REG) & (SR_SEL
| SR_IO)) == (SR_SEL | SR_IO)) {
- done = 0;
- dprintk(NDEBUG_INTR, ("scsi%d :
SEL interrupt\n", instance->host_no));
- NCR5380_reselect(instance);
- (void)
NCR5380_read(RESET_PARITY_INTERRUPT_REG);
- } else if (basr & BASR_PARITY_ERROR) {
- dprintk(NDEBUG_INTR, ("scsi%d :
PARITY interrupt\n", instance->host_no));
- (void)
NCR5380_read(RESET_PARITY_INTERRUPT_REG);
- } else if ((NCR5380_read(STATUS_REG) &
SR_RST) == SR_RST) {
- dprintk(NDEBUG_INTR, ("scsi%d :
RESET interrupt\n", instance->host_no));
- (void)
NCR5380_read(RESET_PARITY_INTERRUPT_REG);
- } else {
+ spin_lock_irq(instance->host_lock);
+ /* Look for pending interrupts */
+ NCR5380_setup(instance);
+ basr = NCR5380_read(BUS_AND_STATUS_REG);
+ /* XXX dispatch to appropriate routine if found and done=0 */
+ if (basr & BASR_IRQ) {
+ NCR5380_dprint(NDEBUG_INTR, instance);
+ if ((NCR5380_read(STATUS_REG) & (SR_SEL | SR_IO)) ==
(SR_SEL | SR_IO)) {
+ done = 0;
+ dprintk(NDEBUG_INTR, ("scsi%d : SEL
interrupt\n", instance->host_no));
+ NCR5380_reselect(instance);
+ (void) NCR5380_read(RESET_PARITY_INTERRUPT_REG);
+ } else if (basr & BASR_PARITY_ERROR) {
+ dprintk(NDEBUG_INTR, ("scsi%d : PARITY
interrupt\n", instance->host_no));
+ (void) NCR5380_read(RESET_PARITY_INTERRUPT_REG);
+ } else if ((NCR5380_read(STATUS_REG) & SR_RST) ==
SR_RST) {
+ dprintk(NDEBUG_INTR, ("scsi%d : RESET
interrupt\n", instance->host_no));
+ (void) NCR5380_read(RESET_PARITY_INTERRUPT_REG);
+ } else {
#if defined(REAL_DMA)
- /*
- * We should only get PHASE
MISMATCH and EOP interrupts
- * if we have DMA enabled, so
do a sanity check based on
- * the current setting of the
MODE register.
- */
-
- if ((NCR5380_read(MODE_REG) &
MR_DMA) && ((basr & BASR_END_DMA_TRANSFER) || !(basr & BASR_PHASE_MATCH))) {
- int transfered;
+ /*
+ * We should only get PHASE MISMATCH and EOP
interrupts
+ * if we have DMA enabled, so do a sanity check
based on
+ * the current setting of the MODE register.
+ */
+ if ((NCR5380_read(MODE_REG) & MR_DMA) && ((basr
& BASR_END_DMA_TRANSFER) || !(basr & BASR_PHASE_MATCH))) {
+ int transfered;
- if
(!hostdata->connected)
- panic("scsi%d :
received end of DMA interrupt with no connected cmd\n", instance->hostno);
+ if (!hostdata->connected)
+ panic("scsi%d : received end of
DMA interrupt with no connected cmd\n", instance->hostno);
- transfered =
(hostdata->dmalen - NCR5380_dma_residual(instance));
-
hostdata->connected->SCp.this_residual -= transferred;
-
hostdata->connected->SCp.ptr += transferred;
- hostdata->dmalen = 0;
+ transfered = (hostdata->dmalen -
NCR5380_dma_residual(instance));
+ hostdata->connected->SCp.this_residual
-= transferred;
+ hostdata->connected->SCp.ptr +=
transferred;
+ hostdata->dmalen = 0;
- (void)
NCR5380_read(RESET_PARITY_INTERRUPT_REG);
+ (void)
NCR5380_read(RESET_PARITY_INTERRUPT_REG);
- /* FIXME: we need to
poll briefly then defer a workqueue task ! */
-
NCR5380_poll_politely(hostdata, BUS_AND_STATUS_REG, BASR_ACK, 0, 2*HZ);
+ /* FIXME: we need to poll briefly then
defer a workqueue task ! */
+ NCR5380_poll_politely(hostdata,
BUS_AND_STATUS_REG, BASR_ACK, 0, 2*HZ);
- NCR5380_write(MODE_REG,
MR_BASE);
-
NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
- }
+ NCR5380_write(MODE_REG, MR_BASE);
+ NCR5380_write(INITIATOR_COMMAND_REG,
ICR_BASE);
+ }
#else
- dprintk(NDEBUG_INTR, ("scsi :
unknown interrupt, BASR 0x%X, MR 0x%X, SR 0x%x\n", basr,
NCR5380_read(MODE_REG), NCR5380_read(STATUS_REG)));
- (void)
NCR5380_read(RESET_PARITY_INTERRUPT_REG);
+ dprintk(NDEBUG_INTR, ("scsi : unknown
interrupt, BASR 0x%X, MR 0x%X, SR 0x%x\n", basr, NCR5380_read(MODE_REG),
NCR5380_read(STATUS_REG)));
+ (void) NCR5380_read(RESET_PARITY_INTERRUPT_REG);
#endif
- }
- } /* if BASR_IRQ */
- spin_unlock_irq(instance->host_lock);
- if(!done)
- schedule_work(&hostdata->coroutine);
- } /* if (instance->irq == irq) */
- }
+ }
+ } /* if BASR_IRQ */
+ spin_unlock_irq(instance->host_lock);
+ if (!done)
+ schedule_work(&hostdata->coroutine);
} while (!done);
- return IRQ_RETVAL(handled);
+ return IRQ_HANDLED;
}
#endif
@@ -1480,8 +1322,7 @@
NCR5380_setup(instance);
if (hostdata->selecting) {
- if(instance->irq != SCSI_IRQ_NONE)
- spin_unlock_irq(instance->host_lock);
+ spin_unlock_irq(instance->host_lock);
goto part2; /* RvC: sorry prof. Dijkstra, but it keeps the
rest of the code nearly the same */
}
@@ -1505,8 +1346,7 @@
NCR5380_write(OUTPUT_DATA_REG, hostdata->id_mask);
NCR5380_write(MODE_REG, MR_ARBITRATE);
- if(instance->irq != SCSI_IRQ_NONE)
- spin_unlock_irq(instance->host_lock);
+ spin_unlock_irq(instance->host_lock);
/* We can be relaxed here, interrupts are on, we are
in workqueue context, the birds are singing in the trees */
@@ -1638,8 +1478,7 @@
if (!value && (hostdata->select_time < HZ/4)) {
/* RvC: we still must wait for a device response */
hostdata->select_time++; /* after 25 ticks the device
has failed */
- hostdata->time_expires = jiffies + 1;
- NCR5380_set_timer(instance);
+ NCR5380_set_timer(hostdata, 1);
return 0; /* RvC: we return here with hostdata->selecting
set,
to go to sleep */
}
@@ -1648,8 +1487,7 @@
waiting period */
if ((NCR5380_read(STATUS_REG) & (SR_SEL | SR_IO)) == (SR_SEL | SR_IO)) {
NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
- if(instance->irq != SCSI_IRQ_NONE)
- spin_lock_irq(instance->host_lock);
+ spin_lock_irq(instance->host_lock);
NCR5380_reselect(instance);
printk("scsi%d : reselection after won arbitration?\n",
instance->host_no);
NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
@@ -1675,8 +1513,7 @@
NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
return -1;
}
- if(instance->irq != SCSI_IRQ_NONE)
- spin_lock_irq(instance->host_lock);
+ spin_lock_irq(instance->host_lock);
cmd->result = DID_BAD_TARGET << 16;
collect_stats(hostdata, cmd);
cmd->scsi_done(cmd);
@@ -1715,8 +1552,7 @@
dprintk(NDEBUG_SELECTION, ("scsi%d : target %d selected, going into
MESSAGE OUT phase.\n", instance->host_no, cmd->device->id));
tmp[0] = IDENTIFY(((instance->irq == SCSI_IRQ_NONE) ? 0 : 1),
cmd->device->lun);
- if(instance->irq != SCSI_IRQ_NONE)
- spin_lock_irq(instance->host_lock);
+ spin_lock_irq(instance->host_lock);
len = 1;
cmd->tag = 0;
@@ -1737,8 +1573,7 @@
/* Selection failed */
failed:
- if(instance->irq != SCSI_IRQ_NONE)
- spin_lock_irq(instance->host_lock);
+ spin_lock_irq(instance->host_lock);
return -1;
}
@@ -1814,8 +1649,7 @@
while (!((tmp = NCR5380_read(STATUS_REG)) & SR_REQ) &&
!break_allowed);
if (!(tmp & SR_REQ)) {
/* timeout condition */
- hostdata->time_expires = jiffies + USLEEP_SLEEP;
- NCR5380_set_timer(instance);
+ NCR5380_set_timer(hostdata, USLEEP_SLEEP);
break;
}
@@ -2653,9 +2487,8 @@
*/
NCR5380_transfer_pio(instance, &phase, &len,
&data);
if (!cmd->device->disconnect &&
should_disconnect(cmd->cmnd[0])) {
- hostdata->time_expires = jiffies +
USLEEP_SLEEP;
dprintk(NDEBUG_USLEEP, ("scsi%d :
issued command, sleeping until %ul\n", instance->host_no,
hostdata->time_expires));
- NCR5380_set_timer(instance);
+ NCR5380_set_timer(hostdata,
USLEEP_SLEEP);
return;
}
break;
@@ -2674,9 +2507,8 @@
/* RvC: go to sleep if polling time expired
*/
if (!cmd->device->disconnect && time_after_eq(jiffies,
poll_time)) {
- hostdata->time_expires = jiffies + USLEEP_SLEEP;
dprintk(NDEBUG_USLEEP, ("scsi%d : poll timed
out, sleeping until %ul\n", instance->host_no, hostdata->time_expires));
- NCR5380_set_timer(instance);
+ NCR5380_set_timer(hostdata, USLEEP_SLEEP);
return;
}
}
--- 1.9/drivers/scsi/NCR5380.h Thu Aug 21 10:36:23 2003
+++ edited/drivers/scsi/NCR5380.h Tue Nov 4 16:42:59 2003
@@ -248,10 +248,9 @@
#define FLAG_DTC3181E 16 /* DTC3181E */
#ifndef ASM
struct NCR5380_hostdata {
NCR5380_implementation_fields; /* implementation specific */
struct Scsi_Host *host; /* Host backpointer */
- struct NCR5380_hostdata *next; /* Next in our hot chain */
unsigned char id_mask, id_higher_mask; /* 1 << id, all bits greater */
unsigned char targets_present; /* targets we have connected
to, so we can call a select
--- 1.24/drivers/scsi/g_NCR5380.c Thu Oct 2 09:12:16 2003
+++ edited/drivers/scsi/g_NCR5380.c Wed Nov 5 10:21:04 2003
@@ -445,7 +445,7 @@
instance->irq = NCR5380_probe_irq(instance, 0xffff);
if (instance->irq != SCSI_IRQ_NONE)
- if (request_irq(instance->irq, generic_NCR5380_intr,
SA_INTERRUPT, "NCR5380", NULL)) {
+ if (request_irq(instance->irq, generic_NCR5380_intr,
SA_INTERRUPT, "NCR5380", instance)) {
printk(KERN_WARNING "scsi%d : IRQ%d not free,
interrupts disabled\n", instance->host_no, instance->irq);
instance->irq = SCSI_IRQ_NONE;
}
-
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