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atari_NCR5380.c
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atari_NCR5380.c
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/*
* NCR 5380 generic driver routines. These should make it *trivial*
* to implement 5380 SCSI drivers under Linux with a non-trantor
* architecture.
*
* Note that these routines also work with NR53c400 family chips.
*
* Copyright 1993, Drew Eckhardt
* Visionary Computing
* (Unix and Linux consulting and custom programming)
* +1 (303) 666-5836
*
* For more information, please consult
*
* NCR 5380 Family
* SCSI Protocol Controller
* Databook
*
* NCR Microelectronics
* 1635 Aeroplaza Drive
* Colorado Springs, CO 80916
* 1+ (719) 578-3400
* 1+ (800) 334-5454
*/
/*
* ++roman: To port the 5380 driver to the Atari, I had to do some changes in
* this file, too:
*
* - Some of the debug statements were incorrect (undefined variables and the
* like). I fixed that.
*
* - In information_transfer(), I think a #ifdef was wrong. Looking at the
* possible DMA transfer size should also happen for REAL_DMA. I added this
* in the #if statement.
*
* - When using real DMA, information_transfer() should return in a DATAOUT
* phase after starting the DMA. It has nothing more to do.
*
* - The interrupt service routine should run main after end of DMA, too (not
* only after RESELECTION interrupts). Additionally, it should _not_ test
* for more interrupts after running main, since a DMA process may have
* been started and interrupts are turned on now. The new int could happen
* inside the execution of NCR5380_intr(), leading to recursive
* calls.
*
* - I've added a function merge_contiguous_buffers() that tries to
* merge scatter-gather buffers that are located at contiguous
* physical addresses and can be processed with the same DMA setup.
* Since most scatter-gather operations work on a page (4K) of
* 4 buffers (1K), in more than 90% of all cases three interrupts and
* DMA setup actions are saved.
*
* - I've deleted all the stuff for AUTOPROBE_IRQ, REAL_DMA_POLL, PSEUDO_DMA
* and USLEEP, because these were messing up readability and will never be
* needed for Atari SCSI.
*
* - I've revised the NCR5380_main() calling scheme (relax the 'main_running'
* stuff), and 'main' is executed in a bottom half if awoken by an
* interrupt.
*
* - The code was quite cluttered up by "#if (NDEBUG & NDEBUG_*) printk..."
* constructs. In my eyes, this made the source rather unreadable, so I
* finally replaced that by the *_PRINTK() macros.
*
*/
/*
* Further development / testing that should be done :
* 1. Test linked command handling code after Eric is ready with
* the high level code.
*/
/* Adapted for the sun3 by Sam Creasey. */
#include <scsi/scsi_dbg.h>
#include <scsi/scsi_transport_spi.h>
#if (NDEBUG & NDEBUG_LISTS)
#define LIST(x, y) \
do { \
printk("LINE:%d Adding %p to %p\n", \
__LINE__, (void*)(x), (void*)(y)); \
if ((x) == (y)) \
udelay(5); \
} while (0)
#define REMOVE(w, x, y, z) \
do { \
printk("LINE:%d Removing: %p->%p %p->%p \n", \
__LINE__, (void*)(w), (void*)(x), \
(void*)(y), (void*)(z)); \
if ((x) == (y)) \
udelay(5); \
} while (0)
#else
#define LIST(x,y)
#define REMOVE(w,x,y,z)
#endif
#ifndef notyet
#undef LINKED
#endif
/*
* Design
*
* 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.
*
* 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
* unlimited number of commands may be queued, letting
* more commands propagate from the higher driver levels giving higher
* throughput. Note that both I_T_L and I_T_L_Q nexuses are supported,
* allowing multiple commands to propagate all the way to a SCSI-II device
* while a command is already executing.
*
*
* Issues specific to the NCR5380 :
*
* When used in a PIO or pseudo-dma mode, the NCR5380 is a braindead
* piece of hardware that requires you to sit in a loop polling for
* the REQ signal as long as you are connected. Some devices are
* brain dead (ie, many TEXEL CD ROM drives) and won't disconnect
* while doing long seek operations.
*
* The workaround for this is to keep track of devices that have
* disconnected. If the device hasn't disconnected, for commands that
* should disconnect, we do something like
*
* while (!REQ is asserted) { sleep for N usecs; poll for M usecs }
*
* Some tweaking of N and M needs to be done. An algorithm based
* on "time to data" would give the best results as long as short time
* to datas (ie, on the same track) were considered, however these
* broken devices are the exception rather than the rule and I'd rather
* spend my time optimizing for the normal case.
*
* Architecture :
*
* At the heart of the design is a coroutine, NCR5380_main,
* 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.
* if the target goes into MSG IN and sends a DISCONNECT message,
* the command structure is placed into the per instance disconnected
* queue, and NCR5380_main tries to find more work. If the target is
* idle for too long, the system will try to sleep.
*
* If a command has disconnected, eventually an interrupt will trigger,
* calling NCR5380_intr() which will in turn call NCR5380_reselect
* to reestablish a nexus. This will run main if necessary.
*
* On command termination, the done function will be called as
* appropriate.
*
* SCSI pointers are maintained in the SCp field of SCSI command
* structures, being initialized after the command is connected
* in NCR5380_select, and set as appropriate in NCR5380_information_transfer.
* Note that in violation of the standard, an implicit SAVE POINTERS operation
* is done, since some BROKEN disks fail to issue an explicit SAVE POINTERS.
*/
/*
* Using this file :
* This file a skeleton Linux SCSI driver for the NCR 5380 series
* of chips. To use it, you write an architecture specific functions
* and macros and include this file in your driver.
*
* These macros control options :
* AUTOSENSE - if defined, REQUEST SENSE will be performed automatically
* for commands that return with a CHECK CONDITION status.
*
* DIFFERENTIAL - if defined, NCR53c81 chips will use external differential
* transceivers.
*
* LINKED - if defined, linked commands are supported.
*
* REAL_DMA - if defined, REAL DMA is used during the data transfer phases.
*
* SUPPORT_TAGS - if defined, SCSI-2 tagged queuing is used where possible
*
* These macros MUST be defined :
*
* NCR5380_read(register) - read from the specified register
*
* NCR5380_write(register, value) - write to the specific register
*
* NCR5380_implementation_fields - additional fields needed for this
* specific implementation of the NCR5380
*
* Either real DMA *or* pseudo DMA may be implemented
* REAL functions :
* NCR5380_REAL_DMA should be defined if real DMA is to be used.
* Note that the DMA setup functions should return the number of bytes
* that they were able to program the controller for.
*
* Also note that generic i386/PC versions of these macros are
* available as NCR5380_i386_dma_write_setup,
* NCR5380_i386_dma_read_setup, and NCR5380_i386_dma_residual.
*
* NCR5380_dma_write_setup(instance, src, count) - initialize
* NCR5380_dma_read_setup(instance, dst, count) - initialize
* NCR5380_dma_residual(instance); - residual count
*
* PSEUDO functions :
* NCR5380_pwrite(instance, src, count)
* NCR5380_pread(instance, dst, count);
*
* 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.
*/
/* Macros ease life... :-) */
#define SETUP_HOSTDATA(in) \
struct NCR5380_hostdata *hostdata = \
(struct NCR5380_hostdata *)(in)->hostdata
#define HOSTDATA(in) ((struct NCR5380_hostdata *)(in)->hostdata)
#define NEXT(cmd) ((struct scsi_cmnd *)(cmd)->host_scribble)
#define SET_NEXT(cmd,next) ((cmd)->host_scribble = (void *)(next))
#define NEXTADDR(cmd) ((struct scsi_cmnd **)&(cmd)->host_scribble)
#define HOSTNO instance->host_no
#define H_NO(cmd) (cmd)->device->host->host_no
#ifdef SUPPORT_TAGS
/*
* Functions for handling tagged queuing
* =====================================
*
* ++roman (01/96): Now I've implemented SCSI-2 tagged queuing. Some notes:
*
* Using consecutive numbers for the tags is no good idea in my eyes. There
* could be wrong re-usings if the counter (8 bit!) wraps and some early
* command has been preempted for a long time. My solution: a bitfield for
* remembering used tags.
*
* There's also the problem that each target has a certain queue size, but we
* cannot know it in advance :-( We just see a QUEUE_FULL status being
* returned. So, in this case, the driver internal queue size assumption is
* reduced to the number of active tags if QUEUE_FULL is returned by the
* target. The command is returned to the mid-level, but with status changed
* to BUSY, since --as I've seen-- the mid-level can't handle QUEUE_FULL
* correctly.
*
* We're also not allowed running tagged commands as long as an untagged
* command is active. And REQUEST SENSE commands after a contingent allegiance
* condition _must_ be untagged. To keep track whether an untagged command has
* been issued, the host->busy array is still employed, as it is without
* support for tagged queuing.
*
* One could suspect that there are possible race conditions between
* is_lun_busy(), cmd_get_tag() and cmd_free_tag(). But I think this isn't the
* case: is_lun_busy() and cmd_get_tag() are both called from NCR5380_main(),
* which already guaranteed to be running at most once. It is also the only
* place where tags/LUNs are allocated. So no other allocation can slip
* between that pair, there could only happen a reselection, which can free a
* tag, but that doesn't hurt. Only the sequence in cmd_free_tag() becomes
* important: the tag bit must be cleared before 'nr_allocated' is decreased.
*/
static void __init init_tags(struct NCR5380_hostdata *hostdata)
{
int target, lun;
struct tag_alloc *ta;
if (!(hostdata->flags & FLAG_TAGGED_QUEUING))
return;
for (target = 0; target < 8; ++target) {
for (lun = 0; lun < 8; ++lun) {
ta = &hostdata->TagAlloc[target][lun];
bitmap_zero(ta->allocated, MAX_TAGS);
ta->nr_allocated = 0;
/* At the beginning, assume the maximum queue size we could
* support (MAX_TAGS). This value will be decreased if the target
* returns QUEUE_FULL status.
*/
ta->queue_size = MAX_TAGS;
}
}
}
/* Check if we can issue a command to this LUN: First see if the LUN is marked
* busy by an untagged command. If the command should use tagged queuing, also
* check that there is a free tag and the target's queue won't overflow. This
* function should be called with interrupts disabled to avoid race
* conditions.
*/
static int is_lun_busy(struct scsi_cmnd *cmd, int should_be_tagged)
{
u8 lun = cmd->device->lun;
SETUP_HOSTDATA(cmd->device->host);
if (hostdata->busy[cmd->device->id] & (1 << lun))
return 1;
if (!should_be_tagged ||
!(hostdata->flags & FLAG_TAGGED_QUEUING) ||
!cmd->device->tagged_supported)
return 0;
if (hostdata->TagAlloc[scmd_id(cmd)][lun].nr_allocated >=
hostdata->TagAlloc[scmd_id(cmd)][lun].queue_size) {
dprintk(NDEBUG_TAGS, "scsi%d: target %d lun %d: no free tags\n",
H_NO(cmd), cmd->device->id, lun);
return 1;
}
return 0;
}
/* Allocate a tag for a command (there are no checks anymore, check_lun_busy()
* must be called before!), or reserve the LUN in 'busy' if the command is
* untagged.
*/
static void cmd_get_tag(struct scsi_cmnd *cmd, int should_be_tagged)
{
u8 lun = cmd->device->lun;
SETUP_HOSTDATA(cmd->device->host);
/* If we or the target don't support tagged queuing, allocate the LUN for
* an untagged command.
*/
if (!should_be_tagged ||
!(hostdata->flags & FLAG_TAGGED_QUEUING) ||
!cmd->device->tagged_supported) {
cmd->tag = TAG_NONE;
hostdata->busy[cmd->device->id] |= (1 << lun);
dprintk(NDEBUG_TAGS, "scsi%d: target %d lun %d now allocated by untagged "
"command\n", H_NO(cmd), cmd->device->id, lun);
} else {
struct tag_alloc *ta = &hostdata->TagAlloc[scmd_id(cmd)][lun];
cmd->tag = find_first_zero_bit(ta->allocated, MAX_TAGS);
set_bit(cmd->tag, ta->allocated);
ta->nr_allocated++;
dprintk(NDEBUG_TAGS, "scsi%d: using tag %d for target %d lun %d "
"(now %d tags in use)\n",
H_NO(cmd), cmd->tag, cmd->device->id,
lun, ta->nr_allocated);
}
}
/* Mark the tag of command 'cmd' as free, or in case of an untagged command,
* unlock the LUN.
*/
static void cmd_free_tag(struct scsi_cmnd *cmd)
{
u8 lun = cmd->device->lun;
SETUP_HOSTDATA(cmd->device->host);
if (cmd->tag == TAG_NONE) {
hostdata->busy[cmd->device->id] &= ~(1 << lun);
dprintk(NDEBUG_TAGS, "scsi%d: target %d lun %d untagged cmd finished\n",
H_NO(cmd), cmd->device->id, lun);
} else if (cmd->tag >= MAX_TAGS) {
printk(KERN_NOTICE "scsi%d: trying to free bad tag %d!\n",
H_NO(cmd), cmd->tag);
} else {
struct tag_alloc *ta = &hostdata->TagAlloc[scmd_id(cmd)][lun];
clear_bit(cmd->tag, ta->allocated);
ta->nr_allocated--;
dprintk(NDEBUG_TAGS, "scsi%d: freed tag %d for target %d lun %d\n",
H_NO(cmd), cmd->tag, cmd->device->id, lun);
}
}
static void free_all_tags(struct NCR5380_hostdata *hostdata)
{
int target, lun;
struct tag_alloc *ta;
if (!(hostdata->flags & FLAG_TAGGED_QUEUING))
return;
for (target = 0; target < 8; ++target) {
for (lun = 0; lun < 8; ++lun) {
ta = &hostdata->TagAlloc[target][lun];
bitmap_zero(ta->allocated, MAX_TAGS);
ta->nr_allocated = 0;
}
}
}
#endif /* SUPPORT_TAGS */
/*
* Function: void merge_contiguous_buffers( struct scsi_cmnd *cmd )
*
* Purpose: Try to merge several scatter-gather requests into one DMA
* transfer. This is possible if the scatter buffers lie on
* physical contiguous addresses.
*
* Parameters: struct scsi_cmnd *cmd
* The command to work on. The first scatter buffer's data are
* assumed to be already transferred into ptr/this_residual.
*/
static void merge_contiguous_buffers(struct scsi_cmnd *cmd)
{
#if !defined(CONFIG_SUN3)
unsigned long endaddr;
#if (NDEBUG & NDEBUG_MERGING)
unsigned long oldlen = cmd->SCp.this_residual;
int cnt = 1;
#endif
for (endaddr = virt_to_phys(cmd->SCp.ptr + cmd->SCp.this_residual - 1) + 1;
cmd->SCp.buffers_residual &&
virt_to_phys(sg_virt(&cmd->SCp.buffer[1])) == endaddr;) {
dprintk(NDEBUG_MERGING, "VTOP(%p) == %08lx -> merging\n",
page_address(sg_page(&cmd->SCp.buffer[1])), endaddr);
#if (NDEBUG & NDEBUG_MERGING)
++cnt;
#endif
++cmd->SCp.buffer;
--cmd->SCp.buffers_residual;
cmd->SCp.this_residual += cmd->SCp.buffer->length;
endaddr += cmd->SCp.buffer->length;
}
#if (NDEBUG & NDEBUG_MERGING)
if (oldlen != cmd->SCp.this_residual)
dprintk(NDEBUG_MERGING, "merged %d buffers from %p, new length %08x\n",
cnt, cmd->SCp.ptr, cmd->SCp.this_residual);
#endif
#endif /* !defined(CONFIG_SUN3) */
}
/**
* initialize_SCp - init the scsi pointer field
* @cmd: command block to set up
*
* Set up the internal fields in the SCSI command.
*/
static inline void initialize_SCp(struct scsi_cmnd *cmd)
{
/*
* Initialize the Scsi Pointer field so that all of the commands in the
* various queues are valid.
*/
if (scsi_bufflen(cmd)) {
cmd->SCp.buffer = scsi_sglist(cmd);
cmd->SCp.buffers_residual = scsi_sg_count(cmd) - 1;
cmd->SCp.ptr = sg_virt(cmd->SCp.buffer);
cmd->SCp.this_residual = cmd->SCp.buffer->length;
/* ++roman: Try to merge some scatter-buffers if they are at
* contiguous physical addresses.
*/
merge_contiguous_buffers(cmd);
} else {
cmd->SCp.buffer = NULL;
cmd->SCp.buffers_residual = 0;
cmd->SCp.ptr = NULL;
cmd->SCp.this_residual = 0;
}
}
#include <linux/delay.h>
#if NDEBUG
static struct {
unsigned char mask;
const char *name;
} signals[] = {
{ SR_DBP, "PARITY"}, { SR_RST, "RST" }, { SR_BSY, "BSY" },
{ SR_REQ, "REQ" }, { SR_MSG, "MSG" }, { SR_CD, "CD" }, { SR_IO, "IO" },
{ SR_SEL, "SEL" }, {0, NULL}
}, basrs[] = {
{BASR_ATN, "ATN"}, {BASR_ACK, "ACK"}, {0, NULL}
}, icrs[] = {
{ICR_ASSERT_RST, "ASSERT RST"},{ICR_ASSERT_ACK, "ASSERT ACK"},
{ICR_ASSERT_BSY, "ASSERT BSY"}, {ICR_ASSERT_SEL, "ASSERT SEL"},
{ICR_ASSERT_ATN, "ASSERT ATN"}, {ICR_ASSERT_DATA, "ASSERT DATA"},
{0, NULL}
}, mrs[] = {
{MR_BLOCK_DMA_MODE, "MODE BLOCK DMA"}, {MR_TARGET, "MODE TARGET"},
{MR_ENABLE_PAR_CHECK, "MODE PARITY CHECK"}, {MR_ENABLE_PAR_INTR,
"MODE PARITY INTR"}, {MR_ENABLE_EOP_INTR,"MODE EOP INTR"},
{MR_MONITOR_BSY, "MODE MONITOR BSY"},
{MR_DMA_MODE, "MODE DMA"}, {MR_ARBITRATE, "MODE ARBITRATION"},
{0, NULL}
};
/**
* NCR5380_print - print scsi bus signals
* @instance: adapter state to dump
*
* Print the SCSI bus signals for debugging purposes
*/
static void NCR5380_print(struct Scsi_Host *instance)
{
unsigned char status, data, basr, mr, icr, i;
unsigned long flags;
local_irq_save(flags);
data = NCR5380_read(CURRENT_SCSI_DATA_REG);
status = NCR5380_read(STATUS_REG);
mr = NCR5380_read(MODE_REG);
icr = NCR5380_read(INITIATOR_COMMAND_REG);
basr = NCR5380_read(BUS_AND_STATUS_REG);
local_irq_restore(flags);
printk("STATUS_REG: %02x ", status);
for (i = 0; signals[i].mask; ++i)
if (status & signals[i].mask)
printk(",%s", signals[i].name);
printk("\nBASR: %02x ", basr);
for (i = 0; basrs[i].mask; ++i)
if (basr & basrs[i].mask)
printk(",%s", basrs[i].name);
printk("\nICR: %02x ", icr);
for (i = 0; icrs[i].mask; ++i)
if (icr & icrs[i].mask)
printk(",%s", icrs[i].name);
printk("\nMODE: %02x ", mr);
for (i = 0; mrs[i].mask; ++i)
if (mr & mrs[i].mask)
printk(",%s", mrs[i].name);
printk("\n");
}
static struct {
unsigned char value;
const char *name;
} phases[] = {
{PHASE_DATAOUT, "DATAOUT"}, {PHASE_DATAIN, "DATAIN"}, {PHASE_CMDOUT, "CMDOUT"},
{PHASE_STATIN, "STATIN"}, {PHASE_MSGOUT, "MSGOUT"}, {PHASE_MSGIN, "MSGIN"},
{PHASE_UNKNOWN, "UNKNOWN"}
};
/**
* NCR5380_print_phase - show SCSI phase
* @instance: adapter to dump
*
* Print the current SCSI phase for debugging purposes
*
* Locks: none
*/
static void NCR5380_print_phase(struct Scsi_Host *instance)
{
unsigned char status;
int i;
status = NCR5380_read(STATUS_REG);
if (!(status & SR_REQ))
printk(KERN_DEBUG "scsi%d: REQ not asserted, phase unknown.\n", HOSTNO);
else {
for (i = 0; (phases[i].value != PHASE_UNKNOWN) &&
(phases[i].value != (status & PHASE_MASK)); ++i)
;
printk(KERN_DEBUG "scsi%d: phase %s\n", HOSTNO, phases[i].name);
}
}
#endif
/*
* ++roman: New scheme of calling NCR5380_main()
*
* If we're not in an interrupt, we can call our main directly, it cannot be
* already running. Else, we queue it on a task queue, if not 'main_running'
* tells us that a lower level is already executing it. This way,
* 'main_running' needs not be protected in a special way.
*
* queue_main() is a utility function for putting our main onto the task
* queue, if main_running is false. It should be called only from a
* interrupt or bottom half.
*/
#include <linux/gfp.h>
#include <linux/workqueue.h>
#include <linux/interrupt.h>
static inline void queue_main(struct NCR5380_hostdata *hostdata)
{
if (!hostdata->main_running) {
/* If in interrupt and NCR5380_main() not already running,
queue it on the 'immediate' task queue, to be processed
immediately after the current interrupt processing has
finished. */
schedule_work(&hostdata->main_task);
}
/* else: nothing to do: the running NCR5380_main() will pick up
any newly queued command. */
}
/**
* NCR58380_info - report driver and host information
* @instance: relevant scsi host instance
*
* For use as the host template info() handler.
*
* Locks: none
*/
static const char *NCR5380_info(struct Scsi_Host *instance)
{
struct NCR5380_hostdata *hostdata = shost_priv(instance);
return hostdata->info;
}
static void prepare_info(struct Scsi_Host *instance)
{
struct NCR5380_hostdata *hostdata = shost_priv(instance);
snprintf(hostdata->info, sizeof(hostdata->info),
"%s, io_port 0x%lx, n_io_port %d, "
"base 0x%lx, irq %d, "
"can_queue %d, cmd_per_lun %d, "
"sg_tablesize %d, this_id %d, "
"flags { %s}, "
"options { %s} ",
instance->hostt->name, instance->io_port, instance->n_io_port,
instance->base, instance->irq,
instance->can_queue, instance->cmd_per_lun,
instance->sg_tablesize, instance->this_id,
hostdata->flags & FLAG_TAGGED_QUEUING ? "TAGGED_QUEUING " : "",
#ifdef DIFFERENTIAL
"DIFFERENTIAL "
#endif
#ifdef REAL_DMA
"REAL_DMA "
#endif
#ifdef PARITY
"PARITY "
#endif
#ifdef SUPPORT_TAGS
"SUPPORT_TAGS "
#endif
"");
}
/**
* NCR5380_print_status - dump controller info
* @instance: controller to dump
*
* Print commands in the various queues, called from NCR5380_abort
* to aid debugging.
*/
static void lprint_Scsi_Cmnd(struct scsi_cmnd *cmd)
{
int i, s;
unsigned char *command;
printk("scsi%d: destination target %d, lun %llu\n",
H_NO(cmd), cmd->device->id, cmd->device->lun);
printk(KERN_CONT " command = ");
command = cmd->cmnd;
printk(KERN_CONT "%2d (0x%02x)", command[0], command[0]);
for (i = 1, s = COMMAND_SIZE(command[0]); i < s; ++i)
printk(KERN_CONT " %02x", command[i]);
printk("\n");
}
static void NCR5380_print_status(struct Scsi_Host *instance)
{
struct NCR5380_hostdata *hostdata;
struct scsi_cmnd *ptr;
unsigned long flags;
NCR5380_dprint(NDEBUG_ANY, instance);
NCR5380_dprint_phase(NDEBUG_ANY, instance);
hostdata = (struct NCR5380_hostdata *)instance->hostdata;
local_irq_save(flags);
printk("NCR5380: coroutine is%s running.\n",
hostdata->main_running ? "" : "n't");
if (!hostdata->connected)
printk("scsi%d: no currently connected command\n", HOSTNO);
else
lprint_Scsi_Cmnd((struct scsi_cmnd *) hostdata->connected);
printk("scsi%d: issue_queue\n", HOSTNO);
for (ptr = (struct scsi_cmnd *)hostdata->issue_queue; ptr; ptr = NEXT(ptr))
lprint_Scsi_Cmnd(ptr);
printk("scsi%d: disconnected_queue\n", HOSTNO);
for (ptr = (struct scsi_cmnd *) hostdata->disconnected_queue; ptr;
ptr = NEXT(ptr))
lprint_Scsi_Cmnd(ptr);
local_irq_restore(flags);
printk("\n");
}
static void show_Scsi_Cmnd(struct scsi_cmnd *cmd, struct seq_file *m)
{
int i, s;
unsigned char *command;
seq_printf(m, "scsi%d: destination target %d, lun %llu\n",
H_NO(cmd), cmd->device->id, cmd->device->lun);
seq_puts(m, " command = ");
command = cmd->cmnd;
seq_printf(m, "%2d (0x%02x)", command[0], command[0]);
for (i = 1, s = COMMAND_SIZE(command[0]); i < s; ++i)
seq_printf(m, " %02x", command[i]);
seq_putc(m, '\n');
}
static int __maybe_unused NCR5380_show_info(struct seq_file *m,
struct Scsi_Host *instance)
{
struct NCR5380_hostdata *hostdata;
struct scsi_cmnd *ptr;
unsigned long flags;
hostdata = (struct NCR5380_hostdata *)instance->hostdata;
local_irq_save(flags);
seq_printf(m, "NCR5380: coroutine is%s running.\n",
hostdata->main_running ? "" : "n't");
if (!hostdata->connected)
seq_printf(m, "scsi%d: no currently connected command\n", HOSTNO);
else
show_Scsi_Cmnd((struct scsi_cmnd *) hostdata->connected, m);
seq_printf(m, "scsi%d: issue_queue\n", HOSTNO);
for (ptr = (struct scsi_cmnd *)hostdata->issue_queue; ptr; ptr = NEXT(ptr))
show_Scsi_Cmnd(ptr, m);
seq_printf(m, "scsi%d: disconnected_queue\n", HOSTNO);
for (ptr = (struct scsi_cmnd *) hostdata->disconnected_queue; ptr;
ptr = NEXT(ptr))
show_Scsi_Cmnd(ptr, m);
local_irq_restore(flags);
return 0;
}
/**
* NCR5380_init - initialise an NCR5380
* @instance: adapter to configure
* @flags: control flags
*
* Initializes *instance and corresponding 5380 chip,
* with flags OR'd into the initial flags value.
*
* Notes : I assume that the host, hostno, and id bits have been
* set correctly. I don't care about the irq and other fields.
*
* Returns 0 for success
*/
static int __init NCR5380_init(struct Scsi_Host *instance, int flags)
{
int i;
SETUP_HOSTDATA(instance);
hostdata->host = instance;
hostdata->aborted = 0;
hostdata->id_mask = 1 << instance->this_id;
hostdata->id_higher_mask = 0;
for (i = hostdata->id_mask; i <= 0x80; i <<= 1)
if (i > hostdata->id_mask)
hostdata->id_higher_mask |= i;
for (i = 0; i < 8; ++i)
hostdata->busy[i] = 0;
#ifdef SUPPORT_TAGS
init_tags(hostdata);
#endif
#if defined (REAL_DMA)
hostdata->dma_len = 0;
#endif
hostdata->targets_present = 0;
hostdata->connected = NULL;
hostdata->issue_queue = NULL;
hostdata->disconnected_queue = NULL;
hostdata->flags = flags;
INIT_WORK(&hostdata->main_task, NCR5380_main);
prepare_info(instance);
NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
NCR5380_write(MODE_REG, MR_BASE);
NCR5380_write(TARGET_COMMAND_REG, 0);
NCR5380_write(SELECT_ENABLE_REG, 0);
return 0;
}
/**
* NCR5380_exit - remove an NCR5380
* @instance: adapter to remove
*
* Assumes that no more work can be queued (e.g. by NCR5380_intr).
*/
static void NCR5380_exit(struct Scsi_Host *instance)
{
struct NCR5380_hostdata *hostdata = shost_priv(instance);
cancel_work_sync(&hostdata->main_task);
}
/**
* NCR5380_queue_command - queue a command
* @instance: the relevant SCSI adapter
* @cmd: SCSI command
*
* cmd is added to the per instance issue_queue, with minor
* twiddling done to the host specific fields of cmd. If the
* main coroutine is not running, it is restarted.
*/
static int NCR5380_queue_command(struct Scsi_Host *instance,
struct scsi_cmnd *cmd)
{
struct NCR5380_hostdata *hostdata = shost_priv(instance);
struct scsi_cmnd *tmp;
unsigned long flags;
#if (NDEBUG & NDEBUG_NO_WRITE)
switch (cmd->cmnd[0]) {
case WRITE_6:
case WRITE_10:
printk(KERN_NOTICE "scsi%d: WRITE attempted with NO_WRITE debugging flag set\n",
H_NO(cmd));
cmd->result = (DID_ERROR << 16);
cmd->scsi_done(cmd);
return 0;
}
#endif /* (NDEBUG & NDEBUG_NO_WRITE) */
/*
* We use the host_scribble field as a pointer to the next command
* in a queue
*/
SET_NEXT(cmd, NULL);
cmd->result = 0;
/*
* Insert the cmd into the issue queue. Note that REQUEST SENSE
* commands are added to the head of the queue since any command will
* clear the contingent allegiance condition that exists and the
* sense data is only guaranteed to be valid while the condition exists.
*/
/* ++guenther: now that the issue queue is being set up, we can lock ST-DMA.
* Otherwise a running NCR5380_main may steal the lock.
* Lock before actually inserting due to fairness reasons explained in
* atari_scsi.c. If we insert first, then it's impossible for this driver
* to release the lock.
* Stop timer for this command while waiting for the lock, or timeouts
* may happen (and they really do), and it's no good if the command doesn't
* appear in any of the queues.
* ++roman: Just disabling the NCR interrupt isn't sufficient here,
* because also a timer int can trigger an abort or reset, which would
* alter queues and touch the lock.
*/
if (!NCR5380_acquire_dma_irq(instance))
return SCSI_MLQUEUE_HOST_BUSY;
local_irq_save(flags);
/*
* Insert the cmd into the issue queue. Note that REQUEST SENSE
* commands are added to the head of the queue since any command will
* clear the contingent allegiance condition that exists and the
* sense data is only guaranteed to be valid while the condition exists.
*/
if (!(hostdata->issue_queue) || (cmd->cmnd[0] == REQUEST_SENSE)) {
LIST(cmd, hostdata->issue_queue);
SET_NEXT(cmd, hostdata->issue_queue);
hostdata->issue_queue = cmd;
} else {
for (tmp = (struct scsi_cmnd *)hostdata->issue_queue;
NEXT(tmp); tmp = NEXT(tmp))
;
LIST(cmd, tmp);
SET_NEXT(tmp, cmd);
}
local_irq_restore(flags);
dprintk(NDEBUG_QUEUES, "scsi%d: command added to %s of queue\n", H_NO(cmd),
(cmd->cmnd[0] == REQUEST_SENSE) ? "head" : "tail");
/* If queue_command() is called from an interrupt (real one or bottom
* half), we let queue_main() do the job of taking care about main. If it
* is already running, this is a no-op, else main will be queued.
*
* If we're not in an interrupt, we can call NCR5380_main()
* unconditionally, because it cannot be already running.
*/
if (in_interrupt() || irqs_disabled())
queue_main(hostdata);
else
NCR5380_main(&hostdata->main_task);
return 0;
}
static inline void maybe_release_dma_irq(struct Scsi_Host *instance)
{
struct NCR5380_hostdata *hostdata = shost_priv(instance);
/* Caller does the locking needed to set & test these data atomically */
if (!hostdata->disconnected_queue &&
!hostdata->issue_queue &&
!hostdata->connected &&
!hostdata->retain_dma_intr)
NCR5380_release_dma_irq(instance);
}
/**
* NCR5380_main - NCR state machines
*
* NCR5380_main is a coroutine that runs as long as more work can
* be done on the NCR5380 host adapters in a system. Both
* NCR5380_queue_command() and NCR5380_intr() will try to start it
* in case it is not running.
*
* Locks: called as its own thread with no locks held.
*/
static void NCR5380_main(struct work_struct *work)
{
struct NCR5380_hostdata *hostdata =
container_of(work, struct NCR5380_hostdata, main_task);
struct Scsi_Host *instance = hostdata->host;
struct scsi_cmnd *tmp, *prev;
int done;
unsigned long flags;
/*
* We run (with interrupts disabled) until we're sure that none of
* the host adapters have anything that can be done, at which point
* we set main_running to 0 and exit.
*
* Interrupts are enabled before doing various other internal
* instructions, after we've decided that we need to run through
* the loop again.
*
* this should prevent any race conditions.
*
* ++roman: Just disabling the NCR interrupt isn't sufficient here,
* because also a timer int can trigger an abort or reset, which can
* alter queues and touch the Falcon lock.
*/
/* Tell int handlers main() is now already executing. Note that
no races are possible here. If an int comes in before
'main_running' is set here, and queues/executes main via the
task queue, it doesn't do any harm, just this instance of main
won't find any work left to do. */
if (hostdata->main_running)
return;
hostdata->main_running = 1;
local_save_flags(flags);
do {
local_irq_disable(); /* Freeze request queues */
done = 1;
if (!hostdata->connected) {
dprintk(NDEBUG_MAIN, "scsi%d: not connected\n", HOSTNO);
/*
* Search through the issue_queue for a command destined
* for a target that's not busy.
*/
#if (NDEBUG & NDEBUG_LISTS)
for (tmp = (struct scsi_cmnd *) hostdata->issue_queue, prev = NULL;
tmp && (tmp != prev); prev = tmp, tmp = NEXT(tmp))
;
/*printk("%p ", tmp);*/
if ((tmp == prev) && tmp)
printk(" LOOP\n");
/* else printk("\n"); */
#endif
for (tmp = (struct scsi_cmnd *) hostdata->issue_queue,
prev = NULL; tmp; prev = tmp, tmp = NEXT(tmp)) {
u8 lun = tmp->device->lun;
dprintk(NDEBUG_LISTS,
"MAIN tmp=%p target=%d busy=%d lun=%d\n",
tmp, scmd_id(tmp), hostdata->busy[scmd_id(tmp)],
lun);
/* When we find one, remove it from the issue queue. */