/
mesh.c
2077 lines (1885 loc) · 53.4 KB
/
mesh.c
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/*
* SCSI low-level driver for the MESH (Macintosh Enhanced SCSI Hardware)
* bus adaptor found on Power Macintosh computers.
* We assume the MESH is connected to a DBDMA (descriptor-based DMA)
* controller.
*
* Paul Mackerras, August 1996.
* Copyright (C) 1996 Paul Mackerras.
*
* Apr. 21 2002 - BenH Rework bus reset code for new error handler
* Add delay after initial bus reset
* Add module parameters
*
* Sep. 27 2003 - BenH Move to new driver model, fix some write posting
* issues
* To do:
* - handle aborts correctly
* - retry arbitration if lost (unless higher levels do this for us)
* - power down the chip when no device is detected
*/
#include <linux/config.h>
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/delay.h>
#include <linux/types.h>
#include <linux/string.h>
#include <linux/slab.h>
#include <linux/blkdev.h>
#include <linux/proc_fs.h>
#include <linux/stat.h>
#include <linux/interrupt.h>
#include <linux/reboot.h>
#include <linux/spinlock.h>
#include <asm/dbdma.h>
#include <asm/io.h>
#include <asm/pgtable.h>
#include <asm/prom.h>
#include <asm/system.h>
#include <asm/irq.h>
#include <asm/hydra.h>
#include <asm/processor.h>
#include <asm/machdep.h>
#include <asm/pmac_feature.h>
#include <asm/pci-bridge.h>
#include <asm/macio.h>
#include <scsi/scsi.h>
#include <scsi/scsi_cmnd.h>
#include <scsi/scsi_device.h>
#include <scsi/scsi_host.h>
#include "mesh.h"
#if 1
#undef KERN_DEBUG
#define KERN_DEBUG KERN_WARNING
#endif
MODULE_AUTHOR("Paul Mackerras (paulus@samba.org)");
MODULE_DESCRIPTION("PowerMac MESH SCSI driver");
MODULE_LICENSE("GPL");
static int sync_rate = CONFIG_SCSI_MESH_SYNC_RATE;
static int sync_targets = 0xff;
static int resel_targets = 0xff;
static int debug_targets = 0; /* print debug for these targets */
static int init_reset_delay = CONFIG_SCSI_MESH_RESET_DELAY_MS;
module_param(sync_rate, int, 0);
MODULE_PARM_DESC(sync_rate, "Synchronous rate (0..10, 0=async)");
module_param(sync_targets, int, 0);
MODULE_PARM_DESC(sync_targets, "Bitmask of targets allowed to set synchronous");
module_param(resel_targets, int, 0);
MODULE_PARM_DESC(resel_targets, "Bitmask of targets allowed to set disconnect");
module_param(debug_targets, int, 0644);
MODULE_PARM_DESC(debug_targets, "Bitmask of debugged targets");
module_param(init_reset_delay, int, 0);
MODULE_PARM_DESC(init_reset_delay, "Initial bus reset delay (0=no reset)");
static int mesh_sync_period = 100;
static int mesh_sync_offset = 0;
static unsigned char use_active_neg = 0; /* bit mask for SEQ_ACTIVE_NEG if used */
#define ALLOW_SYNC(tgt) ((sync_targets >> (tgt)) & 1)
#define ALLOW_RESEL(tgt) ((resel_targets >> (tgt)) & 1)
#define ALLOW_DEBUG(tgt) ((debug_targets >> (tgt)) & 1)
#define DEBUG_TARGET(cmd) ((cmd) && ALLOW_DEBUG((cmd)->device->id))
#undef MESH_DBG
#define N_DBG_LOG 50
#define N_DBG_SLOG 20
#define NUM_DBG_EVENTS 13
#undef DBG_USE_TB /* bombs on 601 */
struct dbglog {
char *fmt;
u32 tb;
u8 phase;
u8 bs0;
u8 bs1;
u8 tgt;
int d;
};
enum mesh_phase {
idle,
arbitrating,
selecting,
commanding,
dataing,
statusing,
busfreeing,
disconnecting,
reselecting,
sleeping
};
enum msg_phase {
msg_none,
msg_out,
msg_out_xxx,
msg_out_last,
msg_in,
msg_in_bad,
};
enum sdtr_phase {
do_sdtr,
sdtr_sent,
sdtr_done
};
struct mesh_target {
enum sdtr_phase sdtr_state;
int sync_params;
int data_goes_out; /* guess as to data direction */
struct scsi_cmnd *current_req;
u32 saved_ptr;
#ifdef MESH_DBG
int log_ix;
int n_log;
struct dbglog log[N_DBG_LOG];
#endif
};
struct mesh_state {
volatile struct mesh_regs __iomem *mesh;
int meshintr;
volatile struct dbdma_regs __iomem *dma;
int dmaintr;
struct Scsi_Host *host;
struct mesh_state *next;
struct scsi_cmnd *request_q;
struct scsi_cmnd *request_qtail;
enum mesh_phase phase; /* what we're currently trying to do */
enum msg_phase msgphase;
int conn_tgt; /* target we're connected to */
struct scsi_cmnd *current_req; /* req we're currently working on */
int data_ptr;
int dma_started;
int dma_count;
int stat;
int aborting;
int expect_reply;
int n_msgin;
u8 msgin[16];
int n_msgout;
int last_n_msgout;
u8 msgout[16];
struct dbdma_cmd *dma_cmds; /* space for dbdma commands, aligned */
dma_addr_t dma_cmd_bus;
void *dma_cmd_space;
int dma_cmd_size;
int clk_freq;
struct mesh_target tgts[8];
struct macio_dev *mdev;
struct pci_dev* pdev;
#ifdef MESH_DBG
int log_ix;
int n_log;
struct dbglog log[N_DBG_SLOG];
#endif
};
/*
* Driver is too messy, we need a few prototypes...
*/
static void mesh_done(struct mesh_state *ms, int start_next);
static void mesh_interrupt(int irq, void *dev_id, struct pt_regs *ptregs);
static void cmd_complete(struct mesh_state *ms);
static void set_dma_cmds(struct mesh_state *ms, struct scsi_cmnd *cmd);
static void halt_dma(struct mesh_state *ms);
static void phase_mismatch(struct mesh_state *ms);
/*
* Some debugging & logging routines
*/
#ifdef MESH_DBG
static inline u32 readtb(void)
{
u32 tb;
#ifdef DBG_USE_TB
/* Beware: if you enable this, it will crash on 601s. */
asm ("mftb %0" : "=r" (tb) : );
#else
tb = 0;
#endif
return tb;
}
static void dlog(struct mesh_state *ms, char *fmt, int a)
{
struct mesh_target *tp = &ms->tgts[ms->conn_tgt];
struct dbglog *tlp, *slp;
tlp = &tp->log[tp->log_ix];
slp = &ms->log[ms->log_ix];
tlp->fmt = fmt;
tlp->tb = readtb();
tlp->phase = (ms->msgphase << 4) + ms->phase;
tlp->bs0 = ms->mesh->bus_status0;
tlp->bs1 = ms->mesh->bus_status1;
tlp->tgt = ms->conn_tgt;
tlp->d = a;
*slp = *tlp;
if (++tp->log_ix >= N_DBG_LOG)
tp->log_ix = 0;
if (tp->n_log < N_DBG_LOG)
++tp->n_log;
if (++ms->log_ix >= N_DBG_SLOG)
ms->log_ix = 0;
if (ms->n_log < N_DBG_SLOG)
++ms->n_log;
}
static void dumplog(struct mesh_state *ms, int t)
{
struct mesh_target *tp = &ms->tgts[t];
struct dbglog *lp;
int i;
if (tp->n_log == 0)
return;
i = tp->log_ix - tp->n_log;
if (i < 0)
i += N_DBG_LOG;
tp->n_log = 0;
do {
lp = &tp->log[i];
printk(KERN_DEBUG "mesh log %d: bs=%.2x%.2x ph=%.2x ",
t, lp->bs1, lp->bs0, lp->phase);
#ifdef DBG_USE_TB
printk("tb=%10u ", lp->tb);
#endif
printk(lp->fmt, lp->d);
printk("\n");
if (++i >= N_DBG_LOG)
i = 0;
} while (i != tp->log_ix);
}
static void dumpslog(struct mesh_state *ms)
{
struct dbglog *lp;
int i;
if (ms->n_log == 0)
return;
i = ms->log_ix - ms->n_log;
if (i < 0)
i += N_DBG_SLOG;
ms->n_log = 0;
do {
lp = &ms->log[i];
printk(KERN_DEBUG "mesh log: bs=%.2x%.2x ph=%.2x t%d ",
lp->bs1, lp->bs0, lp->phase, lp->tgt);
#ifdef DBG_USE_TB
printk("tb=%10u ", lp->tb);
#endif
printk(lp->fmt, lp->d);
printk("\n");
if (++i >= N_DBG_SLOG)
i = 0;
} while (i != ms->log_ix);
}
#else
static inline void dlog(struct mesh_state *ms, char *fmt, int a)
{}
static inline void dumplog(struct mesh_state *ms, int tgt)
{}
static inline void dumpslog(struct mesh_state *ms)
{}
#endif /* MESH_DBG */
#define MKWORD(a, b, c, d) (((a) << 24) + ((b) << 16) + ((c) << 8) + (d))
static void
mesh_dump_regs(struct mesh_state *ms)
{
volatile struct mesh_regs __iomem *mr = ms->mesh;
volatile struct dbdma_regs __iomem *md = ms->dma;
int t;
struct mesh_target *tp;
printk(KERN_DEBUG "mesh: state at %p, regs at %p, dma at %p\n",
ms, mr, md);
printk(KERN_DEBUG " ct=%4x seq=%2x bs=%4x fc=%2x "
"exc=%2x err=%2x im=%2x int=%2x sp=%2x\n",
(mr->count_hi << 8) + mr->count_lo, mr->sequence,
(mr->bus_status1 << 8) + mr->bus_status0, mr->fifo_count,
mr->exception, mr->error, mr->intr_mask, mr->interrupt,
mr->sync_params);
while(in_8(&mr->fifo_count))
printk(KERN_DEBUG " fifo data=%.2x\n",in_8(&mr->fifo));
printk(KERN_DEBUG " dma stat=%x cmdptr=%x\n",
in_le32(&md->status), in_le32(&md->cmdptr));
printk(KERN_DEBUG " phase=%d msgphase=%d conn_tgt=%d data_ptr=%d\n",
ms->phase, ms->msgphase, ms->conn_tgt, ms->data_ptr);
printk(KERN_DEBUG " dma_st=%d dma_ct=%d n_msgout=%d\n",
ms->dma_started, ms->dma_count, ms->n_msgout);
for (t = 0; t < 8; ++t) {
tp = &ms->tgts[t];
if (tp->current_req == NULL)
continue;
printk(KERN_DEBUG " target %d: req=%p goes_out=%d saved_ptr=%d\n",
t, tp->current_req, tp->data_goes_out, tp->saved_ptr);
}
}
/*
* Flush write buffers on the bus path to the mesh
*/
static inline void mesh_flush_io(volatile struct mesh_regs __iomem *mr)
{
(void)in_8(&mr->mesh_id);
}
/*
* Complete a SCSI command
*/
static void mesh_completed(struct mesh_state *ms, struct scsi_cmnd *cmd)
{
(*cmd->scsi_done)(cmd);
}
/* Called with meshinterrupt disabled, initialize the chipset
* and eventually do the initial bus reset. The lock must not be
* held since we can schedule.
*/
static void mesh_init(struct mesh_state *ms)
{
volatile struct mesh_regs __iomem *mr = ms->mesh;
volatile struct dbdma_regs __iomem *md = ms->dma;
mesh_flush_io(mr);
udelay(100);
/* Reset controller */
out_le32(&md->control, (RUN|PAUSE|FLUSH|WAKE) << 16); /* stop dma */
out_8(&mr->exception, 0xff); /* clear all exception bits */
out_8(&mr->error, 0xff); /* clear all error bits */
out_8(&mr->sequence, SEQ_RESETMESH);
mesh_flush_io(mr);
udelay(10);
out_8(&mr->intr_mask, INT_ERROR | INT_EXCEPTION | INT_CMDDONE);
out_8(&mr->source_id, ms->host->this_id);
out_8(&mr->sel_timeout, 25); /* 250ms */
out_8(&mr->sync_params, ASYNC_PARAMS);
if (init_reset_delay) {
printk(KERN_INFO "mesh: performing initial bus reset...\n");
/* Reset bus */
out_8(&mr->bus_status1, BS1_RST); /* assert RST */
mesh_flush_io(mr);
udelay(30); /* leave it on for >= 25us */
out_8(&mr->bus_status1, 0); /* negate RST */
mesh_flush_io(mr);
/* Wait for bus to come back */
msleep(init_reset_delay);
}
/* Reconfigure controller */
out_8(&mr->interrupt, 0xff); /* clear all interrupt bits */
out_8(&mr->sequence, SEQ_FLUSHFIFO);
mesh_flush_io(mr);
udelay(1);
out_8(&mr->sync_params, ASYNC_PARAMS);
out_8(&mr->sequence, SEQ_ENBRESEL);
ms->phase = idle;
ms->msgphase = msg_none;
}
static void mesh_start_cmd(struct mesh_state *ms, struct scsi_cmnd *cmd)
{
volatile struct mesh_regs __iomem *mr = ms->mesh;
int t, id;
id = cmd->device->id;
ms->current_req = cmd;
ms->tgts[id].data_goes_out = cmd->sc_data_direction == DMA_TO_DEVICE;
ms->tgts[id].current_req = cmd;
#if 1
if (DEBUG_TARGET(cmd)) {
int i;
printk(KERN_DEBUG "mesh_start: %p ser=%lu tgt=%d cmd=",
cmd, cmd->serial_number, id);
for (i = 0; i < cmd->cmd_len; ++i)
printk(" %x", cmd->cmnd[i]);
printk(" use_sg=%d buffer=%p bufflen=%u\n",
cmd->use_sg, cmd->request_buffer, cmd->request_bufflen);
}
#endif
if (ms->dma_started)
panic("mesh: double DMA start !\n");
ms->phase = arbitrating;
ms->msgphase = msg_none;
ms->data_ptr = 0;
ms->dma_started = 0;
ms->n_msgout = 0;
ms->last_n_msgout = 0;
ms->expect_reply = 0;
ms->conn_tgt = id;
ms->tgts[id].saved_ptr = 0;
ms->stat = DID_OK;
ms->aborting = 0;
#ifdef MESH_DBG
ms->tgts[id].n_log = 0;
dlog(ms, "start cmd=%x", (int) cmd);
#endif
/* Off we go */
dlog(ms, "about to arb, intr/exc/err/fc=%.8x",
MKWORD(mr->interrupt, mr->exception, mr->error, mr->fifo_count));
out_8(&mr->interrupt, INT_CMDDONE);
out_8(&mr->sequence, SEQ_ENBRESEL);
mesh_flush_io(mr);
udelay(1);
if (in_8(&mr->bus_status1) & (BS1_BSY | BS1_SEL)) {
/*
* Some other device has the bus or is arbitrating for it -
* probably a target which is about to reselect us.
*/
dlog(ms, "busy b4 arb, intr/exc/err/fc=%.8x",
MKWORD(mr->interrupt, mr->exception,
mr->error, mr->fifo_count));
for (t = 100; t > 0; --t) {
if ((in_8(&mr->bus_status1) & (BS1_BSY | BS1_SEL)) == 0)
break;
if (in_8(&mr->interrupt) != 0) {
dlog(ms, "intr b4 arb, intr/exc/err/fc=%.8x",
MKWORD(mr->interrupt, mr->exception,
mr->error, mr->fifo_count));
mesh_interrupt(0, (void *)ms, NULL);
if (ms->phase != arbitrating)
return;
}
udelay(1);
}
if (in_8(&mr->bus_status1) & (BS1_BSY | BS1_SEL)) {
/* XXX should try again in a little while */
ms->stat = DID_BUS_BUSY;
ms->phase = idle;
mesh_done(ms, 0);
return;
}
}
/*
* Apparently the mesh has a bug where it will assert both its
* own bit and the target's bit on the bus during arbitration.
*/
out_8(&mr->dest_id, mr->source_id);
/*
* There appears to be a race with reselection sometimes,
* where a target reselects us just as we issue the
* arbitrate command. It seems that then the arbitrate
* command just hangs waiting for the bus to be free
* without giving us a reselection exception.
* The only way I have found to get it to respond correctly
* is this: disable reselection before issuing the arbitrate
* command, then after issuing it, if it looks like a target
* is trying to reselect us, reset the mesh and then enable
* reselection.
*/
out_8(&mr->sequence, SEQ_DISRESEL);
if (in_8(&mr->interrupt) != 0) {
dlog(ms, "intr after disresel, intr/exc/err/fc=%.8x",
MKWORD(mr->interrupt, mr->exception,
mr->error, mr->fifo_count));
mesh_interrupt(0, (void *)ms, NULL);
if (ms->phase != arbitrating)
return;
dlog(ms, "after intr after disresel, intr/exc/err/fc=%.8x",
MKWORD(mr->interrupt, mr->exception,
mr->error, mr->fifo_count));
}
out_8(&mr->sequence, SEQ_ARBITRATE);
for (t = 230; t > 0; --t) {
if (in_8(&mr->interrupt) != 0)
break;
udelay(1);
}
dlog(ms, "after arb, intr/exc/err/fc=%.8x",
MKWORD(mr->interrupt, mr->exception, mr->error, mr->fifo_count));
if (in_8(&mr->interrupt) == 0 && (in_8(&mr->bus_status1) & BS1_SEL)
&& (in_8(&mr->bus_status0) & BS0_IO)) {
/* looks like a reselection - try resetting the mesh */
dlog(ms, "resel? after arb, intr/exc/err/fc=%.8x",
MKWORD(mr->interrupt, mr->exception, mr->error, mr->fifo_count));
out_8(&mr->sequence, SEQ_RESETMESH);
mesh_flush_io(mr);
udelay(10);
out_8(&mr->interrupt, INT_ERROR | INT_EXCEPTION | INT_CMDDONE);
out_8(&mr->intr_mask, INT_ERROR | INT_EXCEPTION | INT_CMDDONE);
out_8(&mr->sequence, SEQ_ENBRESEL);
mesh_flush_io(mr);
for (t = 10; t > 0 && in_8(&mr->interrupt) == 0; --t)
udelay(1);
dlog(ms, "tried reset after arb, intr/exc/err/fc=%.8x",
MKWORD(mr->interrupt, mr->exception, mr->error, mr->fifo_count));
#ifndef MESH_MULTIPLE_HOSTS
if (in_8(&mr->interrupt) == 0 && (in_8(&mr->bus_status1) & BS1_SEL)
&& (in_8(&mr->bus_status0) & BS0_IO)) {
printk(KERN_ERR "mesh: controller not responding"
" to reselection!\n");
/*
* If this is a target reselecting us, and the
* mesh isn't responding, the higher levels of
* the scsi code will eventually time out and
* reset the bus.
*/
}
#endif
}
}
/*
* Start the next command for a MESH.
* Should be called with interrupts disabled.
*/
static void mesh_start(struct mesh_state *ms)
{
struct scsi_cmnd *cmd, *prev, *next;
if (ms->phase != idle || ms->current_req != NULL) {
printk(KERN_ERR "inappropriate mesh_start (phase=%d, ms=%p)",
ms->phase, ms);
return;
}
while (ms->phase == idle) {
prev = NULL;
for (cmd = ms->request_q; ; cmd = (struct scsi_cmnd *) cmd->host_scribble) {
if (cmd == NULL)
return;
if (ms->tgts[cmd->device->id].current_req == NULL)
break;
prev = cmd;
}
next = (struct scsi_cmnd *) cmd->host_scribble;
if (prev == NULL)
ms->request_q = next;
else
prev->host_scribble = (void *) next;
if (next == NULL)
ms->request_qtail = prev;
mesh_start_cmd(ms, cmd);
}
}
static void mesh_done(struct mesh_state *ms, int start_next)
{
struct scsi_cmnd *cmd;
struct mesh_target *tp = &ms->tgts[ms->conn_tgt];
cmd = ms->current_req;
ms->current_req = NULL;
tp->current_req = NULL;
if (cmd) {
cmd->result = (ms->stat << 16) + cmd->SCp.Status;
if (ms->stat == DID_OK)
cmd->result += (cmd->SCp.Message << 8);
if (DEBUG_TARGET(cmd)) {
printk(KERN_DEBUG "mesh_done: result = %x, data_ptr=%d, buflen=%d\n",
cmd->result, ms->data_ptr, cmd->request_bufflen);
if ((cmd->cmnd[0] == 0 || cmd->cmnd[0] == 0x12 || cmd->cmnd[0] == 3)
&& cmd->request_buffer != 0) {
unsigned char *b = cmd->request_buffer;
printk(KERN_DEBUG "buffer = %x %x %x %x %x %x %x %x\n",
b[0], b[1], b[2], b[3], b[4], b[5], b[6], b[7]);
}
}
cmd->SCp.this_residual -= ms->data_ptr;
mesh_completed(ms, cmd);
}
if (start_next) {
out_8(&ms->mesh->sequence, SEQ_ENBRESEL);
mesh_flush_io(ms->mesh);
udelay(1);
ms->phase = idle;
mesh_start(ms);
}
}
static inline void add_sdtr_msg(struct mesh_state *ms)
{
int i = ms->n_msgout;
ms->msgout[i] = EXTENDED_MESSAGE;
ms->msgout[i+1] = 3;
ms->msgout[i+2] = EXTENDED_SDTR;
ms->msgout[i+3] = mesh_sync_period/4;
ms->msgout[i+4] = (ALLOW_SYNC(ms->conn_tgt)? mesh_sync_offset: 0);
ms->n_msgout = i + 5;
}
static void set_sdtr(struct mesh_state *ms, int period, int offset)
{
struct mesh_target *tp = &ms->tgts[ms->conn_tgt];
volatile struct mesh_regs __iomem *mr = ms->mesh;
int v, tr;
tp->sdtr_state = sdtr_done;
if (offset == 0) {
/* asynchronous */
if (SYNC_OFF(tp->sync_params))
printk(KERN_INFO "mesh: target %d now asynchronous\n",
ms->conn_tgt);
tp->sync_params = ASYNC_PARAMS;
out_8(&mr->sync_params, ASYNC_PARAMS);
return;
}
/*
* We need to compute ceil(clk_freq * period / 500e6) - 2
* without incurring overflow.
*/
v = (ms->clk_freq / 5000) * period;
if (v <= 250000) {
/* special case: sync_period == 5 * clk_period */
v = 0;
/* units of tr are 100kB/s */
tr = (ms->clk_freq + 250000) / 500000;
} else {
/* sync_period == (v + 2) * 2 * clk_period */
v = (v + 99999) / 100000 - 2;
if (v > 15)
v = 15; /* oops */
tr = ((ms->clk_freq / (v + 2)) + 199999) / 200000;
}
if (offset > 15)
offset = 15; /* can't happen */
tp->sync_params = SYNC_PARAMS(offset, v);
out_8(&mr->sync_params, tp->sync_params);
printk(KERN_INFO "mesh: target %d synchronous at %d.%d MB/s\n",
ms->conn_tgt, tr/10, tr%10);
}
static void start_phase(struct mesh_state *ms)
{
int i, seq, nb;
volatile struct mesh_regs __iomem *mr = ms->mesh;
volatile struct dbdma_regs __iomem *md = ms->dma;
struct scsi_cmnd *cmd = ms->current_req;
struct mesh_target *tp = &ms->tgts[ms->conn_tgt];
dlog(ms, "start_phase nmo/exc/fc/seq = %.8x",
MKWORD(ms->n_msgout, mr->exception, mr->fifo_count, mr->sequence));
out_8(&mr->interrupt, INT_ERROR | INT_EXCEPTION | INT_CMDDONE);
seq = use_active_neg + (ms->n_msgout? SEQ_ATN: 0);
switch (ms->msgphase) {
case msg_none:
break;
case msg_in:
out_8(&mr->count_hi, 0);
out_8(&mr->count_lo, 1);
out_8(&mr->sequence, SEQ_MSGIN + seq);
ms->n_msgin = 0;
return;
case msg_out:
/*
* To make sure ATN drops before we assert ACK for
* the last byte of the message, we have to do the
* last byte specially.
*/
if (ms->n_msgout <= 0) {
printk(KERN_ERR "mesh: msg_out but n_msgout=%d\n",
ms->n_msgout);
mesh_dump_regs(ms);
ms->msgphase = msg_none;
break;
}
if (ALLOW_DEBUG(ms->conn_tgt)) {
printk(KERN_DEBUG "mesh: sending %d msg bytes:",
ms->n_msgout);
for (i = 0; i < ms->n_msgout; ++i)
printk(" %x", ms->msgout[i]);
printk("\n");
}
dlog(ms, "msgout msg=%.8x", MKWORD(ms->n_msgout, ms->msgout[0],
ms->msgout[1], ms->msgout[2]));
out_8(&mr->count_hi, 0);
out_8(&mr->sequence, SEQ_FLUSHFIFO);
mesh_flush_io(mr);
udelay(1);
/*
* If ATN is not already asserted, we assert it, then
* issue a SEQ_MSGOUT to get the mesh to drop ACK.
*/
if ((in_8(&mr->bus_status0) & BS0_ATN) == 0) {
dlog(ms, "bus0 was %.2x explicitly asserting ATN", mr->bus_status0);
out_8(&mr->bus_status0, BS0_ATN); /* explicit ATN */
mesh_flush_io(mr);
udelay(1);
out_8(&mr->count_lo, 1);
out_8(&mr->sequence, SEQ_MSGOUT + seq);
out_8(&mr->bus_status0, 0); /* release explicit ATN */
dlog(ms,"hace: after explicit ATN bus0=%.2x",mr->bus_status0);
}
if (ms->n_msgout == 1) {
/*
* We can't issue the SEQ_MSGOUT without ATN
* until the target has asserted REQ. The logic
* in cmd_complete handles both situations:
* REQ already asserted or not.
*/
cmd_complete(ms);
} else {
out_8(&mr->count_lo, ms->n_msgout - 1);
out_8(&mr->sequence, SEQ_MSGOUT + seq);
for (i = 0; i < ms->n_msgout - 1; ++i)
out_8(&mr->fifo, ms->msgout[i]);
}
return;
default:
printk(KERN_ERR "mesh bug: start_phase msgphase=%d\n",
ms->msgphase);
}
switch (ms->phase) {
case selecting:
out_8(&mr->dest_id, ms->conn_tgt);
out_8(&mr->sequence, SEQ_SELECT + SEQ_ATN);
break;
case commanding:
out_8(&mr->sync_params, tp->sync_params);
out_8(&mr->count_hi, 0);
if (cmd) {
out_8(&mr->count_lo, cmd->cmd_len);
out_8(&mr->sequence, SEQ_COMMAND + seq);
for (i = 0; i < cmd->cmd_len; ++i)
out_8(&mr->fifo, cmd->cmnd[i]);
} else {
out_8(&mr->count_lo, 6);
out_8(&mr->sequence, SEQ_COMMAND + seq);
for (i = 0; i < 6; ++i)
out_8(&mr->fifo, 0);
}
break;
case dataing:
/* transfer data, if any */
if (!ms->dma_started) {
set_dma_cmds(ms, cmd);
out_le32(&md->cmdptr, virt_to_phys(ms->dma_cmds));
out_le32(&md->control, (RUN << 16) | RUN);
ms->dma_started = 1;
}
nb = ms->dma_count;
if (nb > 0xfff0)
nb = 0xfff0;
ms->dma_count -= nb;
ms->data_ptr += nb;
out_8(&mr->count_lo, nb);
out_8(&mr->count_hi, nb >> 8);
out_8(&mr->sequence, (tp->data_goes_out?
SEQ_DATAOUT: SEQ_DATAIN) + SEQ_DMA_MODE + seq);
break;
case statusing:
out_8(&mr->count_hi, 0);
out_8(&mr->count_lo, 1);
out_8(&mr->sequence, SEQ_STATUS + seq);
break;
case busfreeing:
case disconnecting:
out_8(&mr->sequence, SEQ_ENBRESEL);
mesh_flush_io(mr);
udelay(1);
dlog(ms, "enbresel intr/exc/err/fc=%.8x",
MKWORD(mr->interrupt, mr->exception, mr->error,
mr->fifo_count));
out_8(&mr->sequence, SEQ_BUSFREE);
break;
default:
printk(KERN_ERR "mesh: start_phase called with phase=%d\n",
ms->phase);
dumpslog(ms);
}
}
static inline void get_msgin(struct mesh_state *ms)
{
volatile struct mesh_regs __iomem *mr = ms->mesh;
int i, n;
n = mr->fifo_count;
if (n != 0) {
i = ms->n_msgin;
ms->n_msgin = i + n;
for (; n > 0; --n)
ms->msgin[i++] = in_8(&mr->fifo);
}
}
static inline int msgin_length(struct mesh_state *ms)
{
int b, n;
n = 1;
if (ms->n_msgin > 0) {
b = ms->msgin[0];
if (b == 1) {
/* extended message */
n = ms->n_msgin < 2? 2: ms->msgin[1] + 2;
} else if (0x20 <= b && b <= 0x2f) {
/* 2-byte message */
n = 2;
}
}
return n;
}
static void reselected(struct mesh_state *ms)
{
volatile struct mesh_regs __iomem *mr = ms->mesh;
struct scsi_cmnd *cmd;
struct mesh_target *tp;
int b, t, prev;
switch (ms->phase) {
case idle:
break;
case arbitrating:
if ((cmd = ms->current_req) != NULL) {
/* put the command back on the queue */
cmd->host_scribble = (void *) ms->request_q;
if (ms->request_q == NULL)
ms->request_qtail = cmd;
ms->request_q = cmd;
tp = &ms->tgts[cmd->device->id];
tp->current_req = NULL;
}
break;
case busfreeing:
ms->phase = reselecting;
mesh_done(ms, 0);
break;
case disconnecting:
break;
default:
printk(KERN_ERR "mesh: reselected in phase %d/%d tgt %d\n",
ms->msgphase, ms->phase, ms->conn_tgt);
dumplog(ms, ms->conn_tgt);
dumpslog(ms);
}
if (ms->dma_started) {
printk(KERN_ERR "mesh: reselected with DMA started !\n");
halt_dma(ms);
}
ms->current_req = NULL;
ms->phase = dataing;
ms->msgphase = msg_in;
ms->n_msgout = 0;
ms->last_n_msgout = 0;
prev = ms->conn_tgt;
/*
* We seem to get abortive reselections sometimes.
*/
while ((in_8(&mr->bus_status1) & BS1_BSY) == 0) {
static int mesh_aborted_resels;
mesh_aborted_resels++;
out_8(&mr->interrupt, INT_ERROR | INT_EXCEPTION | INT_CMDDONE);
mesh_flush_io(mr);
udelay(1);
out_8(&mr->sequence, SEQ_ENBRESEL);
mesh_flush_io(mr);
udelay(5);
dlog(ms, "extra resel err/exc/fc = %.6x",
MKWORD(0, mr->error, mr->exception, mr->fifo_count));
}
out_8(&mr->interrupt, INT_ERROR | INT_EXCEPTION | INT_CMDDONE);
mesh_flush_io(mr);
udelay(1);
out_8(&mr->sequence, SEQ_ENBRESEL);
mesh_flush_io(mr);
udelay(1);
out_8(&mr->sync_params, ASYNC_PARAMS);
/*
* Find out who reselected us.
*/
if (in_8(&mr->fifo_count) == 0) {
printk(KERN_ERR "mesh: reselection but nothing in fifo?\n");
ms->conn_tgt = ms->host->this_id;
goto bogus;
}
/* get the last byte in the fifo */
do {
b = in_8(&mr->fifo);
dlog(ms, "reseldata %x", b);
} while (in_8(&mr->fifo_count));
for (t = 0; t < 8; ++t)
if ((b & (1 << t)) != 0 && t != ms->host->this_id)
break;
if (b != (1 << t) + (1 << ms->host->this_id)) {
printk(KERN_ERR "mesh: bad reselection data %x\n", b);
ms->conn_tgt = ms->host->this_id;
goto bogus;
}
/*
* Set up to continue with that target's transfer.
*/
ms->conn_tgt = t;
tp = &ms->tgts[t];
out_8(&mr->sync_params, tp->sync_params);
if (ALLOW_DEBUG(t)) {
printk(KERN_DEBUG "mesh: reselected by target %d\n", t);
printk(KERN_DEBUG "mesh: saved_ptr=%x goes_out=%d cmd=%p\n",
tp->saved_ptr, tp->data_goes_out, tp->current_req);
}
ms->current_req = tp->current_req;
if (tp->current_req == NULL) {
printk(KERN_ERR "mesh: reselected by tgt %d but no cmd!\n", t);
goto bogus;
}
ms->data_ptr = tp->saved_ptr;
dlog(ms, "resel prev tgt=%d", prev);
dlog(ms, "resel err/exc=%.4x", MKWORD(0, 0, mr->error, mr->exception));
start_phase(ms);
return;
bogus:
dumplog(ms, ms->conn_tgt);
dumpslog(ms);
ms->data_ptr = 0;
ms->aborting = 1;
start_phase(ms);
}
static void do_abort(struct mesh_state *ms)
{
ms->msgout[0] = ABORT;
ms->n_msgout = 1;
ms->aborting = 1;
ms->stat = DID_ABORT;
dlog(ms, "abort", 0);
}
static void handle_reset(struct mesh_state *ms)
{
int tgt;
struct mesh_target *tp;
struct scsi_cmnd *cmd;
volatile struct mesh_regs __iomem *mr = ms->mesh;
for (tgt = 0; tgt < 8; ++tgt) {
tp = &ms->tgts[tgt];
if ((cmd = tp->current_req) != NULL) {
cmd->result = DID_RESET << 16;
tp->current_req = NULL;
mesh_completed(ms, cmd);
}
ms->tgts[tgt].sdtr_state = do_sdtr;