linux/drivers/scsi/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/module.h>
#include <linux/kernel.h>
#include <linux/delay.h>
#include <linux/types.h>
#include <linux/string.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(struct mesh_state *ms);
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",
scsi_sg_count(cmd), scsi_sglist(cmd), scsi_bufflen(cmd));
}
#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(ms);
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(ms);
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, scsi_bufflen(cmd));
#if 0
/* needs to use sg? */
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]);
}
#endif
}
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;
ms->tgts[tgt].sync_params = ASYNC_PARAMS;
}
ms->current_req = NULL;
while ((cmd = ms->request_q) != NULL) {
ms->request_q = (struct scsi_cmnd *) cmd->host_scribble;
cmd->result = DID_RESET << 16;
mesh_completed(ms, cmd);
}
ms->phase = idle;
ms->msgphase = msg_none;
out_8(&mr->interrupt, INT_ERROR | INT_EXCEPTION | INT_CMDDONE);
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);
}
IRQ: Maintain regs pointer globally rather than passing to IRQ handlers Maintain a per-CPU global "struct pt_regs *" variable which can be used instead of passing regs around manually through all ~1800 interrupt handlers in the Linux kernel. The regs pointer is used in few places, but it potentially costs both stack space and code to pass it around. On the FRV arch, removing the regs parameter from all the genirq function results in a 20% speed up of the IRQ exit path (ie: from leaving timer_interrupt() to leaving do_IRQ()). Where appropriate, an arch may override the generic storage facility and do something different with the variable. On FRV, for instance, the address is maintained in GR28 at all times inside the kernel as part of general exception handling. Having looked over the code, it appears that the parameter may be handed down through up to twenty or so layers of functions. Consider a USB character device attached to a USB hub, attached to a USB controller that posts its interrupts through a cascaded auxiliary interrupt controller. A character device driver may want to pass regs to the sysrq handler through the input layer which adds another few layers of parameter passing. I've build this code with allyesconfig for x86_64 and i386. I've runtested the main part of the code on FRV and i386, though I can't test most of the drivers. I've also done partial conversion for powerpc and MIPS - these at least compile with minimal configurations. This will affect all archs. Mostly the changes should be relatively easy. Take do_IRQ(), store the regs pointer at the beginning, saving the old one: struct pt_regs *old_regs = set_irq_regs(regs); And put the old one back at the end: set_irq_regs(old_regs); Don't pass regs through to generic_handle_irq() or __do_IRQ(). In timer_interrupt(), this sort of change will be necessary: - update_process_times(user_mode(regs)); - profile_tick(CPU_PROFILING, regs); + update_process_times(user_mode(get_irq_regs())); + profile_tick(CPU_PROFILING); I'd like to move update_process_times()'s use of get_irq_regs() into itself, except that i386, alone of the archs, uses something other than user_mode(). Some notes on the interrupt handling in the drivers: (*) input_dev() is now gone entirely. The regs pointer is no longer stored in the input_dev struct. (*) finish_unlinks() in drivers/usb/host/ohci-q.c needs checking. It does something different depending on whether it's been supplied with a regs pointer or not. (*) Various IRQ handler function pointers have been moved to type irq_handler_t. Signed-Off-By: David Howells <dhowells@redhat.com> (cherry picked from 1b16e7ac850969f38b375e511e3fa2f474a33867 commit)
2006-10-05 13:55:46 +00:00
static irqreturn_t do_mesh_interrupt(int irq, void *dev_id)
{
unsigned long flags;
struct mesh_state *ms = dev_id;
struct Scsi_Host *dev = ms->host;
spin_lock_irqsave(dev->host_lock, flags);
mesh_interrupt(ms);
spin_unlock_irqrestore(dev->host_lock, flags);
return IRQ_HANDLED;
}
static void handle_error(struct mesh_state *ms)
{
int err, exc, count;
volatile struct mesh_regs __iomem *mr = ms->mesh;
err = in_8(&mr->error);
exc = in_8(&mr->exception);
out_8(&mr->interrupt, INT_ERROR | INT_EXCEPTION | INT_CMDDONE);
dlog(ms, "error err/exc/fc/cl=%.8x",
MKWORD(err, exc, mr->fifo_count, mr->count_lo));
if (err & ERR_SCSIRESET) {
/* SCSI bus was reset */
printk(KERN_INFO "mesh: SCSI bus reset detected: "
"waiting for end...");
while ((in_8(&mr->bus_status1) & BS1_RST) != 0)
udelay(1);
printk("done\n");
handle_reset(ms);
/* request_q is empty, no point in mesh_start() */
return;
}
if (err & ERR_UNEXPDISC) {
/* Unexpected disconnect */
if (exc & EXC_RESELECTED) {
reselected(ms);
return;
}
if (!ms->aborting) {
printk(KERN_WARNING "mesh: target %d aborted\n",
ms->conn_tgt);
dumplog(ms, ms->conn_tgt);
dumpslog(ms);
}
out_8(&mr->interrupt, INT_CMDDONE);
ms->stat = DID_ABORT;
mesh_done(ms, 1);
return;
}
if (err & ERR_PARITY) {
if (ms->msgphase == msg_in) {
printk(KERN_ERR "mesh: msg parity error, target %d\n",
ms->conn_tgt);
ms->msgout[0] = MSG_PARITY_ERROR;
ms->n_msgout = 1;
ms->msgphase = msg_in_bad;
cmd_complete(ms);
return;
}
if (ms->stat == DID_OK) {
printk(KERN_ERR "mesh: parity error, target %d\n",
ms->conn_tgt);
ms->stat = DID_PARITY;
}
count = (mr->count_hi << 8) + mr->count_lo;
if (count == 0) {
cmd_complete(ms);
} else {
/* reissue the data transfer command */
out_8(&mr->sequence, mr->sequence);
}
return;
}
if (err & ERR_SEQERR) {
if (exc & EXC_RESELECTED) {
/* This can happen if we issue a command to
get the bus just after the target reselects us. */
static int mesh_resel_seqerr;
mesh_resel_seqerr++;
reselected(ms);
return;
}
if (exc == EXC_PHASEMM) {
static int mesh_phasemm_seqerr;
mesh_phasemm_seqerr++;
phase_mismatch(ms);
return;
}
printk(KERN_ERR "mesh: sequence error (err=%x exc=%x)\n",
err, exc);
} else {
printk(KERN_ERR "mesh: unknown error %x (exc=%x)\n", err, exc);
}
mesh_dump_regs(ms);
dumplog(ms, ms->conn_tgt);
if (ms->phase > selecting && (in_8(&mr->bus_status1) & BS1_BSY)) {
/* try to do what the target wants */
do_abort(ms);
phase_mismatch(ms);
return;
}
ms->stat = DID_ERROR;
mesh_done(ms, 1);
}
static void handle_exception(struct mesh_state *ms)
{
int exc;
volatile struct mesh_regs __iomem *mr = ms->mesh;
exc = in_8(&mr->exception);
out_8(&mr->interrupt, INT_EXCEPTION | INT_CMDDONE);
if (exc & EXC_RESELECTED) {
static int mesh_resel_exc;
mesh_resel_exc++;
reselected(ms);
} else if (exc == EXC_ARBLOST) {
printk(KERN_DEBUG "mesh: lost arbitration\n");
ms->stat = DID_BUS_BUSY;
mesh_done(ms, 1);
} else if (exc == EXC_SELTO) {
/* selection timed out */
ms->stat = DID_BAD_TARGET;
mesh_done(ms, 1);
} else if (exc == EXC_PHASEMM) {
/* target wants to do something different:
find out what it wants and do it. */
phase_mismatch(ms);
} else {
printk(KERN_ERR "mesh: can't cope with exception %x\n", exc);
mesh_dump_regs(ms);
dumplog(ms, ms->conn_tgt);
do_abort(ms);
phase_mismatch(ms);
}
}
static void handle_msgin(struct mesh_state *ms)
{
int i, code;
struct scsi_cmnd *cmd = ms->current_req;
struct mesh_target *tp = &ms->tgts[ms->conn_tgt];
if (ms->n_msgin == 0)
return;
code = ms->msgin[0];
if (ALLOW_DEBUG(ms->conn_tgt)) {
printk(KERN_DEBUG "got %d message bytes:", ms->n_msgin);
for (i = 0; i < ms->n_msgin; ++i)
printk(" %x", ms->msgin[i]);
printk("\n");
}
dlog(ms, "msgin msg=%.8x",
MKWORD(ms->n_msgin, code, ms->msgin[1], ms->msgin[2]));
ms->expect_reply = 0;
ms->n_msgout = 0;
if (ms->n_msgin < msgin_length(ms))
goto reject;
if (cmd)
cmd->SCp.Message = code;
switch (code) {
case COMMAND_COMPLETE:
break;
case EXTENDED_MESSAGE:
switch (ms->msgin[2]) {
case EXTENDED_MODIFY_DATA_POINTER:
ms->data_ptr += (ms->msgin[3] << 24) + ms->msgin[6]
+ (ms->msgin[4] << 16) + (ms->msgin[5] << 8);
break;
case EXTENDED_SDTR:
if (tp->sdtr_state != sdtr_sent) {
/* reply with an SDTR */
add_sdtr_msg(ms);
/* limit period to at least his value,
offset to no more than his */
if (ms->msgout[3] < ms->msgin[3])
ms->msgout[3] = ms->msgin[3];
if (ms->msgout[4] > ms->msgin[4])
ms->msgout[4] = ms->msgin[4];
set_sdtr(ms, ms->msgout[3], ms->msgout[4]);
ms->msgphase = msg_out;
} else {
set_sdtr(ms, ms->msgin[3], ms->msgin[4]);
}
break;
default:
goto reject;
}
break;
case SAVE_POINTERS:
tp->saved_ptr = ms->data_ptr;
break;
case RESTORE_POINTERS:
ms->data_ptr = tp->saved_ptr;
break;
case DISCONNECT:
ms->phase = disconnecting;
break;
case ABORT:
break;
case MESSAGE_REJECT:
if (tp->sdtr_state == sdtr_sent)
set_sdtr(ms, 0, 0);
break;
case NOP:
break;
default:
if (IDENTIFY_BASE <= code && code <= IDENTIFY_BASE + 7) {
if (cmd == NULL) {
do_abort(ms);
ms->msgphase = msg_out;
} else if (code != cmd->device->lun + IDENTIFY_BASE) {
printk(KERN_WARNING "mesh: lun mismatch "
"(%d != %d) on reselection from "
"target %d\n", code - IDENTIFY_BASE,
cmd->device->lun, ms->conn_tgt);
}
break;
}
goto reject;
}
return;
reject:
printk(KERN_WARNING "mesh: rejecting message from target %d:",
ms->conn_tgt);
for (i = 0; i < ms->n_msgin; ++i)
printk(" %x", ms->msgin[i]);
printk("\n");
ms->msgout[0] = MESSAGE_REJECT;
ms->n_msgout = 1;
ms->msgphase = msg_out;
}
/*
* Set up DMA commands for transferring data.
*/
static void set_dma_cmds(struct mesh_state *ms, struct scsi_cmnd *cmd)
{
int i, dma_cmd, total, off, dtot;
struct scatterlist *scl;
struct dbdma_cmd *dcmds;
dma_cmd = ms->tgts[ms->conn_tgt].data_goes_out?
OUTPUT_MORE: INPUT_MORE;
dcmds = ms->dma_cmds;
dtot = 0;
if (cmd) {
int nseg;
cmd->SCp.this_residual = scsi_bufflen(cmd);
nseg = scsi_dma_map(cmd);
BUG_ON(nseg < 0);
if (nseg) {
total = 0;
off = ms->data_ptr;
scsi_for_each_sg(cmd, scl, nseg, i) {
u32 dma_addr = sg_dma_address(scl);
u32 dma_len = sg_dma_len(scl);
total += scl->length;
if (off >= dma_len) {
off -= dma_len;
continue;
}
if (dma_len > 0xffff)
panic("mesh: scatterlist element >= 64k");
st_le16(&dcmds->req_count, dma_len - off);
st_le16(&dcmds->command, dma_cmd);
st_le32(&dcmds->phy_addr, dma_addr + off);
dcmds->xfer_status = 0;
++dcmds;
dtot += dma_len - off;
off = 0;
}
}
}
if (dtot == 0) {
/* Either the target has overrun our buffer,
or the caller didn't provide a buffer. */
static char mesh_extra_buf[64];
dtot = sizeof(mesh_extra_buf);
st_le16(&dcmds->req_count, dtot);
st_le32(&dcmds->phy_addr, virt_to_phys(mesh_extra_buf));
dcmds->xfer_status = 0;
++dcmds;
}
dma_cmd += OUTPUT_LAST - OUTPUT_MORE;
st_le16(&dcmds[-1].command, dma_cmd);
memset(dcmds, 0, sizeof(*dcmds));
st_le16(&dcmds->command, DBDMA_STOP);
ms->dma_count = dtot;
}
static void halt_dma(struct mesh_state *ms)
{
volatile struct dbdma_regs __iomem *md = ms->dma;
volatile struct mesh_regs __iomem *mr = ms->mesh;
struct scsi_cmnd *cmd = ms->current_req;
int t, nb;
if (!ms->tgts[ms->conn_tgt].data_goes_out) {
/* wait a little while until the fifo drains */
t = 50;
while (t > 0 && in_8(&mr->fifo_count) != 0
&& (in_le32(&md->status) & ACTIVE) != 0) {
--t;
udelay(1);
}
}
out_le32(&md->control, RUN << 16); /* turn off RUN bit */
nb = (mr->count_hi << 8) + mr->count_lo;
dlog(ms, "halt_dma fc/count=%.6x",
MKWORD(0, mr->fifo_count, 0, nb));
if (ms->tgts[ms->conn_tgt].data_goes_out)
nb += mr->fifo_count;
/* nb is the number of bytes not yet transferred
to/from the target. */
ms->data_ptr -= nb;
dlog(ms, "data_ptr %x", ms->data_ptr);
if (ms->data_ptr < 0) {
printk(KERN_ERR "mesh: halt_dma: data_ptr=%d (nb=%d, ms=%p)\n",
ms->data_ptr, nb, ms);
ms->data_ptr = 0;
#ifdef MESH_DBG
dumplog(ms, ms->conn_tgt);
dumpslog(ms);
#endif /* MESH_DBG */
} else if (cmd && scsi_bufflen(cmd) &&
ms->data_ptr > scsi_bufflen(cmd)) {
printk(KERN_DEBUG "mesh: target %d overrun, "
"data_ptr=%x total=%x goes_out=%d\n",
ms->conn_tgt, ms->data_ptr, scsi_bufflen(cmd),
ms->tgts[ms->conn_tgt].data_goes_out);
}
scsi_dma_unmap(cmd);
ms->dma_started = 0;
}
static void phase_mismatch(struct mesh_state *ms)
{
volatile struct mesh_regs __iomem *mr = ms->mesh;
int phase;
dlog(ms, "phasemm ch/cl/seq/fc=%.8x",
MKWORD(mr->count_hi, mr->count_lo, mr->sequence, mr->fifo_count));
phase = in_8(&mr->bus_status0) & BS0_PHASE;
if (ms->msgphase == msg_out_xxx && phase == BP_MSGOUT) {
/* output the last byte of the message, without ATN */
out_8(&mr->count_lo, 1);
out_8(&mr->sequence, SEQ_MSGOUT + use_active_neg);
mesh_flush_io(mr);
udelay(1);
out_8(&mr->fifo, ms->msgout[ms->n_msgout-1]);
ms->msgphase = msg_out_last;
return;
}
if (ms->msgphase == msg_in) {
get_msgin(ms);
if (ms->n_msgin)
handle_msgin(ms);
}
if (ms->dma_started)
halt_dma(ms);
if (mr->fifo_count) {
out_8(&mr->sequence, SEQ_FLUSHFIFO);
mesh_flush_io(mr);
udelay(1);
}
ms->msgphase = msg_none;
switch (phase) {
case BP_DATAIN:
ms->tgts[ms->conn_tgt].data_goes_out = 0;
ms->phase = dataing;
break;
case BP_DATAOUT:
ms->tgts[ms->conn_tgt].data_goes_out = 1;
ms->phase = dataing;
break;
case BP_COMMAND:
ms->phase = commanding;
break;
case BP_STATUS:
ms->phase = statusing;
break;
case BP_MSGIN:
ms->msgphase = msg_in;
ms->n_msgin = 0;
break;
case BP_MSGOUT:
ms->msgphase = msg_out;
if (ms->n_msgout == 0) {
if (ms->aborting) {
do_abort(ms);
} else {
if (ms->last_n_msgout == 0) {
printk(KERN_DEBUG
"mesh: no msg to repeat\n");
ms->msgout[0] = NOP;
ms->last_n_msgout = 1;
}
ms->n_msgout = ms->last_n_msgout;
}
}
break;
default:
printk(KERN_DEBUG "mesh: unknown scsi phase %x\n", phase);
ms->stat = DID_ERROR;
mesh_done(ms, 1);
return;
}
start_phase(ms);
}
static void cmd_complete(struct mesh_state *ms)
{
volatile struct mesh_regs __iomem *mr = ms->mesh;
struct scsi_cmnd *cmd = ms->current_req;
struct mesh_target *tp = &ms->tgts[ms->conn_tgt];
int seq, n, t;
dlog(ms, "cmd_complete fc=%x", mr->fifo_count);
seq = use_active_neg + (ms->n_msgout? SEQ_ATN: 0);
switch (ms->msgphase) {
case msg_out_xxx:
/* huh? we expected a phase mismatch */
ms->n_msgin = 0;
ms->msgphase = msg_in;
/* fall through */
case msg_in:
/* should have some message bytes in fifo */
get_msgin(ms);
n = msgin_length(ms);
if (ms->n_msgin < n) {
out_8(&mr->count_lo, n - ms->n_msgin);
out_8(&mr->sequence, SEQ_MSGIN + seq);
} else {
ms->msgphase = msg_none;
handle_msgin(ms);
start_phase(ms);
}
break;
case msg_in_bad:
out_8(&mr->sequence, SEQ_FLUSHFIFO);
mesh_flush_io(mr);
udelay(1);
out_8(&mr->count_lo, 1);
out_8(&mr->sequence, SEQ_MSGIN + SEQ_ATN + use_active_neg);
break;
case msg_out:
/*
* To get the right timing on ATN wrt ACK, we have
* to get the MESH to drop ACK, wait until REQ gets
* asserted, then drop ATN. To do this we first
* issue a SEQ_MSGOUT with ATN and wait for REQ,
* then change the command to a SEQ_MSGOUT w/o ATN.
* If we don't see REQ in a reasonable time, we
* change the command to SEQ_MSGIN with ATN,
* wait for the phase mismatch interrupt, then
* issue the SEQ_MSGOUT without ATN.
*/
out_8(&mr->count_lo, 1);
out_8(&mr->sequence, SEQ_MSGOUT + use_active_neg + SEQ_ATN);
t = 30; /* wait up to 30us */
while ((in_8(&mr->bus_status0) & BS0_REQ) == 0 && --t >= 0)
udelay(1);
dlog(ms, "last_mbyte err/exc/fc/cl=%.8x",
MKWORD(mr->error, mr->exception,
mr->fifo_count, mr->count_lo));
if (in_8(&mr->interrupt) & (INT_ERROR | INT_EXCEPTION)) {
/* whoops, target didn't do what we expected */
ms->last_n_msgout = ms->n_msgout;
ms->n_msgout = 0;
if (in_8(&mr->interrupt) & INT_ERROR) {
printk(KERN_ERR "mesh: error %x in msg_out\n",
in_8(&mr->error));
handle_error(ms);
return;
}
if (in_8(&mr->exception) != EXC_PHASEMM)
printk(KERN_ERR "mesh: exc %x in msg_out\n",
in_8(&mr->exception));
else
printk(KERN_DEBUG "mesh: bs0=%x in msg_out\n",
in_8(&mr->bus_status0));
handle_exception(ms);
return;
}
if (in_8(&mr->bus_status0) & BS0_REQ) {
out_8(&mr->sequence, SEQ_MSGOUT + use_active_neg);
mesh_flush_io(mr);
udelay(1);
out_8(&mr->fifo, ms->msgout[ms->n_msgout-1]);
ms->msgphase = msg_out_last;
} else {
out_8(&mr->sequence, SEQ_MSGIN + use_active_neg + SEQ_ATN);
ms->msgphase = msg_out_xxx;
}
break;
case msg_out_last:
ms->last_n_msgout = ms->n_msgout;
ms->n_msgout = 0;
ms->msgphase = ms->expect_reply? msg_in: msg_none;
start_phase(ms);
break;
case msg_none:
switch (ms->phase) {
case idle:
printk(KERN_ERR "mesh: interrupt in idle phase?\n");
dumpslog(ms);
return;
case selecting:
dlog(ms, "Selecting phase at command completion",0);
ms->msgout[0] = IDENTIFY(ALLOW_RESEL(ms->conn_tgt),
(cmd? cmd->device->lun: 0));
ms->n_msgout = 1;
ms->expect_reply = 0;
if (ms->aborting) {
ms->msgout[0] = ABORT;
ms->n_msgout++;
} else if (tp->sdtr_state == do_sdtr) {
/* add SDTR message */
add_sdtr_msg(ms);
ms->expect_reply = 1;
tp->sdtr_state = sdtr_sent;
}
ms->msgphase = msg_out;
/*
* We need to wait for REQ before dropping ATN.
* We wait for at most 30us, then fall back to
* a scheme where we issue a SEQ_COMMAND with ATN,
* which will give us a phase mismatch interrupt
* when REQ does come, and then we send the message.
*/
t = 230; /* wait up to 230us */
while ((in_8(&mr->bus_status0) & BS0_REQ) == 0) {
if (--t < 0) {
dlog(ms, "impatient for req", ms->n_msgout);
ms->msgphase = msg_none;
break;
}
udelay(1);
}
break;
case dataing:
if (ms->dma_count != 0) {
start_phase(ms);
return;
}
/*
* We can get a phase mismatch here if the target
* changes to the status phase, even though we have
* had a command complete interrupt. Then, if we
* issue the SEQ_STATUS command, we'll get a sequence
* error interrupt. Which isn't so bad except that
* occasionally the mesh actually executes the
* SEQ_STATUS *as well as* giving us the sequence
* error and phase mismatch exception.
*/
out_8(&mr->sequence, 0);
out_8(&mr->interrupt,
INT_ERROR | INT_EXCEPTION | INT_CMDDONE);
halt_dma(ms);
break;
case statusing:
if (cmd) {
cmd->SCp.Status = mr->fifo;
if (DEBUG_TARGET(cmd))
printk(KERN_DEBUG "mesh: status is %x\n",
cmd->SCp.Status);
}
ms->msgphase = msg_in;
break;
case busfreeing:
mesh_done(ms, 1);
return;
case disconnecting:
ms->current_req = NULL;
ms->phase = idle;
mesh_start(ms);
return;
default:
break;
}
++ms->phase;
start_phase(ms);
break;
}
}
/*
* Called by midlayer with host locked to queue a new
* request
*/
static int mesh_queue(struct scsi_cmnd *cmd, void (*done)(struct scsi_cmnd *))
{
struct mesh_state *ms;
cmd->scsi_done = done;
cmd->host_scribble = NULL;
ms = (struct mesh_state *) cmd->device->host->hostdata;
if (ms->request_q == NULL)
ms->request_q = cmd;
else
ms->request_qtail->host_scribble = (void *) cmd;
ms->request_qtail = cmd;
if (ms->phase == idle)
mesh_start(ms);
return 0;
}
/*
* Called to handle interrupts, either call by the interrupt
* handler (do_mesh_interrupt) or by other functions in
* exceptional circumstances
*/
static void mesh_interrupt(struct mesh_state *ms)
{
volatile struct mesh_regs __iomem *mr = ms->mesh;
int intr;
#if 0
if (ALLOW_DEBUG(ms->conn_tgt))
printk(KERN_DEBUG "mesh_intr, bs0=%x int=%x exc=%x err=%x "
"phase=%d msgphase=%d\n", mr->bus_status0,
mr->interrupt, mr->exception, mr->error,
ms->phase, ms->msgphase);
#endif
while ((intr = in_8(&mr->interrupt)) != 0) {
dlog(ms, "interrupt intr/err/exc/seq=%.8x",
MKWORD(intr, mr->error, mr->exception, mr->sequence));
if (intr & INT_ERROR) {
handle_error(ms);
} else if (intr & INT_EXCEPTION) {
handle_exception(ms);
} else if (intr & INT_CMDDONE) {
out_8(&mr->interrupt, INT_CMDDONE);
cmd_complete(ms);
}
}
}
/* Todo: here we can at least try to remove the command from the
* queue if it isn't connected yet, and for pending command, assert
* ATN until the bus gets freed.
*/
static int mesh_abort(struct scsi_cmnd *cmd)
{
struct mesh_state *ms = (struct mesh_state *) cmd->device->host->hostdata;
printk(KERN_DEBUG "mesh_abort(%p)\n", cmd);
mesh_dump_regs(ms);
dumplog(ms, cmd->device->id);
dumpslog(ms);
return FAILED;
}
/*
* Called by the midlayer with the lock held to reset the
* SCSI host and bus.
* The midlayer will wait for devices to come back, we don't need
* to do that ourselves
*/
static int mesh_host_reset(struct scsi_cmnd *cmd)
{
struct mesh_state *ms = (struct mesh_state *) cmd->device->host->hostdata;
volatile struct mesh_regs __iomem *mr = ms->mesh;
volatile struct dbdma_regs __iomem *md = ms->dma;
unsigned long flags;
printk(KERN_DEBUG "mesh_host_reset\n");
spin_lock_irqsave(ms->host->host_lock, flags);
/* Reset the controller & dbdma channel */
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(1);
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);
/* Reset the 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 */
/* Complete pending commands */
handle_reset(ms);
spin_unlock_irqrestore(ms->host->host_lock, flags);
return SUCCESS;
}
static void set_mesh_power(struct mesh_state *ms, int state)
{
if (!machine_is(powermac))
return;
if (state) {
pmac_call_feature(PMAC_FTR_MESH_ENABLE, macio_get_of_node(ms->mdev), 0, 1);
msleep(200);
} else {
pmac_call_feature(PMAC_FTR_MESH_ENABLE, macio_get_of_node(ms->mdev), 0, 0);
msleep(10);
}
}
#ifdef CONFIG_PM
static int mesh_suspend(struct macio_dev *mdev, pm_message_t mesg)
{
struct mesh_state *ms = (struct mesh_state *)macio_get_drvdata(mdev);
unsigned long flags;
switch (mesg.event) {
case PM_EVENT_SUSPEND:
case PM_EVENT_HIBERNATE:
case PM_EVENT_FREEZE:
break;
default:
return 0;
}
if (ms->phase == sleeping)
return 0;
scsi_block_requests(ms->host);
spin_lock_irqsave(ms->host->host_lock, flags);
while(ms->phase != idle) {
spin_unlock_irqrestore(ms->host->host_lock, flags);
msleep(10);
spin_lock_irqsave(ms->host->host_lock, flags);
}
ms->phase = sleeping;
spin_unlock_irqrestore(ms->host->host_lock, flags);
disable_irq(ms->meshintr);
set_mesh_power(ms, 0);
return 0;
}
static int mesh_resume(struct macio_dev *mdev)
{
struct mesh_state *ms = (struct mesh_state *)macio_get_drvdata(mdev);
unsigned long flags;
if (ms->phase != sleeping)
return 0;
set_mesh_power(ms, 1);
mesh_init(ms);
spin_lock_irqsave(ms->host->host_lock, flags);
mesh_start(ms);
spin_unlock_irqrestore(ms->host->host_lock, flags);
enable_irq(ms->meshintr);
scsi_unblock_requests(ms->host);
return 0;
}
#endif /* CONFIG_PM */
/*
* If we leave drives set for synchronous transfers (especially
* CDROMs), and reboot to MacOS, it gets confused, poor thing.
* So, on reboot we reset the SCSI bus.
*/
static int mesh_shutdown(struct macio_dev *mdev)
{
struct mesh_state *ms = (struct mesh_state *)macio_get_drvdata(mdev);
volatile struct mesh_regs __iomem *mr;
unsigned long flags;
printk(KERN_INFO "resetting MESH scsi bus(es)\n");
spin_lock_irqsave(ms->host->host_lock, flags);
mr = ms->mesh;
out_8(&mr->intr_mask, 0);
out_8(&mr->interrupt, INT_ERROR | INT_EXCEPTION | INT_CMDDONE);
out_8(&mr->bus_status1, BS1_RST);
mesh_flush_io(mr);
udelay(30);
out_8(&mr->bus_status1, 0);
spin_unlock_irqrestore(ms->host->host_lock, flags);
return 0;
}
static struct scsi_host_template mesh_template = {
.proc_name = "mesh",
.name = "MESH",
.queuecommand = mesh_queue,
.eh_abort_handler = mesh_abort,
.eh_host_reset_handler = mesh_host_reset,
.can_queue = 20,
.this_id = 7,
.sg_tablesize = SG_ALL,
.cmd_per_lun = 2,
.use_clustering = DISABLE_CLUSTERING,
};
static int mesh_probe(struct macio_dev *mdev, const struct of_device_id *match)
{
struct device_node *mesh = macio_get_of_node(mdev);
struct pci_dev* pdev = macio_get_pci_dev(mdev);
int tgt, minper;
const int *cfp;
struct mesh_state *ms;
struct Scsi_Host *mesh_host;
void *dma_cmd_space;
dma_addr_t dma_cmd_bus;
switch (mdev->bus->chip->type) {
case macio_heathrow:
case macio_gatwick:
case macio_paddington:
use_active_neg = 0;
break;
default:
use_active_neg = SEQ_ACTIVE_NEG;
}
if (macio_resource_count(mdev) != 2 || macio_irq_count(mdev) != 2) {
printk(KERN_ERR "mesh: expected 2 addrs and 2 intrs"
" (got %d,%d)\n", macio_resource_count(mdev),
macio_irq_count(mdev));
return -ENODEV;
}
if (macio_request_resources(mdev, "mesh") != 0) {
printk(KERN_ERR "mesh: unable to request memory resources");
return -EBUSY;
}
mesh_host = scsi_host_alloc(&mesh_template, sizeof(struct mesh_state));
if (mesh_host == NULL) {
printk(KERN_ERR "mesh: couldn't register host");
goto out_release;
}
/* Old junk for root discovery, that will die ultimately */
#if !defined(MODULE)
note_scsi_host(mesh, mesh_host);
#endif
mesh_host->base = macio_resource_start(mdev, 0);
mesh_host->irq = macio_irq(mdev, 0);
ms = (struct mesh_state *) mesh_host->hostdata;
macio_set_drvdata(mdev, ms);
ms->host = mesh_host;
ms->mdev = mdev;
ms->pdev = pdev;
ms->mesh = ioremap(macio_resource_start(mdev, 0), 0x1000);
if (ms->mesh == NULL) {
printk(KERN_ERR "mesh: can't map registers\n");
goto out_free;
}
ms->dma = ioremap(macio_resource_start(mdev, 1), 0x1000);
if (ms->dma == NULL) {
printk(KERN_ERR "mesh: can't map registers\n");
iounmap(ms->mesh);
goto out_free;
}
ms->meshintr = macio_irq(mdev, 0);
ms->dmaintr = macio_irq(mdev, 1);
/* Space for dma command list: +1 for stop command,
* +1 to allow for aligning.
*/
ms->dma_cmd_size = (mesh_host->sg_tablesize + 2) * sizeof(struct dbdma_cmd);
/* We use the PCI APIs for now until the generic one gets fixed
* enough or until we get some macio-specific versions
*/
dma_cmd_space = pci_alloc_consistent(macio_get_pci_dev(mdev),
ms->dma_cmd_size,
&dma_cmd_bus);
if (dma_cmd_space == NULL) {
printk(KERN_ERR "mesh: can't allocate DMA table\n");
goto out_unmap;
}
memset(dma_cmd_space, 0, ms->dma_cmd_size);
ms->dma_cmds = (struct dbdma_cmd *) DBDMA_ALIGN(dma_cmd_space);
ms->dma_cmd_space = dma_cmd_space;
ms->dma_cmd_bus = dma_cmd_bus + ((unsigned long)ms->dma_cmds)
- (unsigned long)dma_cmd_space;
ms->current_req = NULL;
for (tgt = 0; tgt < 8; ++tgt) {
ms->tgts[tgt].sdtr_state = do_sdtr;
ms->tgts[tgt].sync_params = ASYNC_PARAMS;
ms->tgts[tgt].current_req = NULL;
}
if ((cfp = of_get_property(mesh, "clock-frequency", NULL)))
ms->clk_freq = *cfp;
else {
printk(KERN_INFO "mesh: assuming 50MHz clock frequency\n");
ms->clk_freq = 50000000;
}
/* The maximum sync rate is clock / 5; increase
* mesh_sync_period if necessary.
*/
minper = 1000000000 / (ms->clk_freq / 5); /* ns */
if (mesh_sync_period < minper)
mesh_sync_period = minper;
/* Power up the chip */
set_mesh_power(ms, 1);
/* Set it up */
mesh_init(ms);
/* Request interrupt */
if (request_irq(ms->meshintr, do_mesh_interrupt, 0, "MESH", ms)) {
printk(KERN_ERR "MESH: can't get irq %d\n", ms->meshintr);
goto out_shutdown;
}
/* Add scsi host & scan */
if (scsi_add_host(mesh_host, &mdev->ofdev.dev))
goto out_release_irq;
scsi_scan_host(mesh_host);
return 0;
out_release_irq:
free_irq(ms->meshintr, ms);
out_shutdown:
/* shutdown & reset bus in case of error or macos can be confused
* at reboot if the bus was set to synchronous mode already
*/
mesh_shutdown(mdev);
set_mesh_power(ms, 0);
pci_free_consistent(macio_get_pci_dev(mdev), ms->dma_cmd_size,
ms->dma_cmd_space, ms->dma_cmd_bus);
out_unmap:
iounmap(ms->dma);
iounmap(ms->mesh);
out_free:
scsi_host_put(mesh_host);
out_release:
macio_release_resources(mdev);
return -ENODEV;
}
static int mesh_remove(struct macio_dev *mdev)
{
struct mesh_state *ms = (struct mesh_state *)macio_get_drvdata(mdev);
struct Scsi_Host *mesh_host = ms->host;
scsi_remove_host(mesh_host);
free_irq(ms->meshintr, ms);
/* Reset scsi bus */
mesh_shutdown(mdev);
/* Shut down chip & termination */
set_mesh_power(ms, 0);
/* Unmap registers & dma controller */
iounmap(ms->mesh);
iounmap(ms->dma);
/* Free DMA commands memory */
pci_free_consistent(macio_get_pci_dev(mdev), ms->dma_cmd_size,
ms->dma_cmd_space, ms->dma_cmd_bus);
/* Release memory resources */
macio_release_resources(mdev);
scsi_host_put(mesh_host);
return 0;
}
static struct of_device_id mesh_match[] =
{
{
.name = "mesh",
},
{
.type = "scsi",
.compatible = "chrp,mesh0"
},
{},
};
MODULE_DEVICE_TABLE (of, mesh_match);
static struct macio_driver mesh_driver =
{
.driver = {
.name = "mesh",
.owner = THIS_MODULE,
.of_match_table = mesh_match,
},
.probe = mesh_probe,
.remove = mesh_remove,
.shutdown = mesh_shutdown,
#ifdef CONFIG_PM
.suspend = mesh_suspend,
.resume = mesh_resume,
#endif
};
static int __init init_mesh(void)
{
/* Calculate sync rate from module parameters */
if (sync_rate > 10)
sync_rate = 10;
if (sync_rate > 0) {
printk(KERN_INFO "mesh: configured for synchronous %d MB/s\n", sync_rate);
mesh_sync_period = 1000 / sync_rate; /* ns */
mesh_sync_offset = 15;
} else
printk(KERN_INFO "mesh: configured for asynchronous\n");
return macio_register_driver(&mesh_driver);
}
static void __exit exit_mesh(void)
{
return macio_unregister_driver(&mesh_driver);
}
module_init(init_mesh);
module_exit(exit_mesh);