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linux/drivers/scsi/mac_esp.c
Finn Thain 02507a80b3 [SCSI] mac_esp: fix PIO mode, take 2 
The mac_esp PIO algorithm no longer works in 2.6.31 and crashes my Centris
660av. So here's a better one.

Also, force async with esp_set_offset() rather than esp_slave_configure().

One of the SCSI drives I tested still doesn't like the PIO mode and fails
with "esp: esp0: Reconnect IRQ2 timeout" (the same drive works fine in
PDMA mode).

This failure happens when esp_reconnect_with_tag() tries to read in two
tag bytes but the chip only provides one (0x20). I don't know what causes
this. I decided not to waste any more time trying to fix it because the
best solution is to rip out the PIO mode altogether and use the DMA
engine.

Signed-off-by: Finn Thain <fthain@telegraphics.com.au>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>
2010-01-18 10:48:10 -06:00

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/* mac_esp.c: ESP front-end for Macintosh Quadra systems.
*
* Adapted from jazz_esp.c and the old mac_esp.c.
*
* The pseudo DMA algorithm is based on the one used in NetBSD.
* See sys/arch/mac68k/obio/esp.c for some background information.
*
* Copyright (C) 2007-2008 Finn Thain
*/
#include <linux/kernel.h>
#include <linux/types.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/platform_device.h>
#include <linux/dma-mapping.h>
#include <linux/scatterlist.h>
#include <linux/delay.h>
#include <linux/io.h>
#include <linux/nubus.h>
#include <asm/irq.h>
#include <asm/dma.h>
#include <asm/macints.h>
#include <asm/macintosh.h>
#include <scsi/scsi_host.h>
#include "esp_scsi.h"
#define DRV_MODULE_NAME "mac_esp"
#define PFX DRV_MODULE_NAME ": "
#define DRV_VERSION "1.000"
#define DRV_MODULE_RELDATE "Sept 15, 2007"
#define MAC_ESP_IO_BASE 0x50F00000
#define MAC_ESP_REGS_QUADRA (MAC_ESP_IO_BASE + 0x10000)
#define MAC_ESP_REGS_QUADRA2 (MAC_ESP_IO_BASE + 0xF000)
#define MAC_ESP_REGS_QUADRA3 (MAC_ESP_IO_BASE + 0x18000)
#define MAC_ESP_REGS_SPACING 0x402
#define MAC_ESP_PDMA_REG 0xF9800024
#define MAC_ESP_PDMA_REG_SPACING 0x4
#define MAC_ESP_PDMA_IO_OFFSET 0x100
#define esp_read8(REG) mac_esp_read8(esp, REG)
#define esp_write8(VAL, REG) mac_esp_write8(esp, VAL, REG)
struct mac_esp_priv {
struct esp *esp;
void __iomem *pdma_regs;
void __iomem *pdma_io;
int error;
};
static struct platform_device *internal_pdev, *external_pdev;
static struct esp *esp_chips[2];
#define MAC_ESP_GET_PRIV(esp) ((struct mac_esp_priv *) \
platform_get_drvdata((struct platform_device *) \
(esp->dev)))
static inline void mac_esp_write8(struct esp *esp, u8 val, unsigned long reg)
{
nubus_writeb(val, esp->regs + reg * 16);
}
static inline u8 mac_esp_read8(struct esp *esp, unsigned long reg)
{
return nubus_readb(esp->regs + reg * 16);
}
/* For pseudo DMA and PIO we need the virtual address
* so this address mapping is the identity mapping.
*/
static dma_addr_t mac_esp_map_single(struct esp *esp, void *buf,
size_t sz, int dir)
{
return (dma_addr_t)buf;
}
static int mac_esp_map_sg(struct esp *esp, struct scatterlist *sg,
int num_sg, int dir)
{
int i;
for (i = 0; i < num_sg; i++)
sg[i].dma_address = (u32)sg_virt(&sg[i]);
return num_sg;
}
static void mac_esp_unmap_single(struct esp *esp, dma_addr_t addr,
size_t sz, int dir)
{
/* Nothing to do. */
}
static void mac_esp_unmap_sg(struct esp *esp, struct scatterlist *sg,
int num_sg, int dir)
{
/* Nothing to do. */
}
static void mac_esp_reset_dma(struct esp *esp)
{
/* Nothing to do. */
}
static void mac_esp_dma_drain(struct esp *esp)
{
/* Nothing to do. */
}
static void mac_esp_dma_invalidate(struct esp *esp)
{
/* Nothing to do. */
}
static int mac_esp_dma_error(struct esp *esp)
{
return MAC_ESP_GET_PRIV(esp)->error;
}
static inline int mac_esp_wait_for_empty_fifo(struct esp *esp)
{
struct mac_esp_priv *mep = MAC_ESP_GET_PRIV(esp);
int i = 500000;
do {
if (!(esp_read8(ESP_FFLAGS) & ESP_FF_FBYTES))
return 0;
if (esp_read8(ESP_STATUS) & ESP_STAT_INTR)
return 1;
udelay(2);
} while (--i);
printk(KERN_ERR PFX "FIFO is not empty (sreg %02x)\n",
esp_read8(ESP_STATUS));
mep->error = 1;
return 1;
}
static inline int mac_esp_wait_for_dreq(struct esp *esp)
{
struct mac_esp_priv *mep = MAC_ESP_GET_PRIV(esp);
int i = 500000;
do {
if (mep->pdma_regs == NULL) {
if (mac_irq_pending(IRQ_MAC_SCSIDRQ))
return 0;
} else {
if (nubus_readl(mep->pdma_regs) & 0x200)
return 0;
}
if (esp_read8(ESP_STATUS) & ESP_STAT_INTR)
return 1;
udelay(2);
} while (--i);
printk(KERN_ERR PFX "PDMA timeout (sreg %02x)\n",
esp_read8(ESP_STATUS));
mep->error = 1;
return 1;
}
#define MAC_ESP_PDMA_LOOP(operands) \
asm volatile ( \
" tstw %1 \n" \
" jbeq 20f \n" \
"1: movew " operands " \n" \
"2: movew " operands " \n" \
"3: movew " operands " \n" \
"4: movew " operands " \n" \
"5: movew " operands " \n" \
"6: movew " operands " \n" \
"7: movew " operands " \n" \
"8: movew " operands " \n" \
"9: movew " operands " \n" \
"10: movew " operands " \n" \
"11: movew " operands " \n" \
"12: movew " operands " \n" \
"13: movew " operands " \n" \
"14: movew " operands " \n" \
"15: movew " operands " \n" \
"16: movew " operands " \n" \
" subqw #1,%1 \n" \
" jbne 1b \n" \
"20: tstw %2 \n" \
" jbeq 30f \n" \
"21: movew " operands " \n" \
" subqw #1,%2 \n" \
" jbne 21b \n" \
"30: tstw %3 \n" \
" jbeq 40f \n" \
"31: moveb " operands " \n" \
"32: nop \n" \
"40: \n" \
" \n" \
" .section __ex_table,\"a\" \n" \
" .align 4 \n" \
" .long 1b,40b \n" \
" .long 2b,40b \n" \
" .long 3b,40b \n" \
" .long 4b,40b \n" \
" .long 5b,40b \n" \
" .long 6b,40b \n" \
" .long 7b,40b \n" \
" .long 8b,40b \n" \
" .long 9b,40b \n" \
" .long 10b,40b \n" \
" .long 11b,40b \n" \
" .long 12b,40b \n" \
" .long 13b,40b \n" \
" .long 14b,40b \n" \
" .long 15b,40b \n" \
" .long 16b,40b \n" \
" .long 21b,40b \n" \
" .long 31b,40b \n" \
" .long 32b,40b \n" \
" .previous \n" \
: "+a" (addr), "+r" (count32), "+r" (count2) \
: "g" (count1), "a" (mep->pdma_io))
static void mac_esp_send_pdma_cmd(struct esp *esp, u32 addr, u32 esp_count,
u32 dma_count, int write, u8 cmd)
{
struct mac_esp_priv *mep = MAC_ESP_GET_PRIV(esp);
unsigned long flags;
local_irq_save(flags);
mep->error = 0;
if (!write)
scsi_esp_cmd(esp, ESP_CMD_FLUSH);
esp_write8((esp_count >> 0) & 0xFF, ESP_TCLOW);
esp_write8((esp_count >> 8) & 0xFF, ESP_TCMED);
scsi_esp_cmd(esp, cmd);
do {
unsigned int count32 = esp_count >> 5;
unsigned int count2 = (esp_count & 0x1F) >> 1;
unsigned int count1 = esp_count & 1;
unsigned int start_addr = addr;
if (mac_esp_wait_for_dreq(esp))
break;
if (write) {
MAC_ESP_PDMA_LOOP("%4@,%0@+");
esp_count -= addr - start_addr;
} else {
unsigned int n;
MAC_ESP_PDMA_LOOP("%0@+,%4@");
if (mac_esp_wait_for_empty_fifo(esp))
break;
n = (esp_read8(ESP_TCMED) << 8) + esp_read8(ESP_TCLOW);
addr = start_addr + esp_count - n;
esp_count = n;
}
} while (esp_count);
local_irq_restore(flags);
}
/*
* Programmed IO routines follow.
*/
static inline unsigned int mac_esp_wait_for_fifo(struct esp *esp)
{
int i = 500000;
do {
unsigned int fbytes = esp_read8(ESP_FFLAGS) & ESP_FF_FBYTES;
if (fbytes)
return fbytes;
udelay(2);
} while (--i);
printk(KERN_ERR PFX "FIFO is empty (sreg %02x)\n",
esp_read8(ESP_STATUS));
return 0;
}
static inline int mac_esp_wait_for_intr(struct esp *esp)
{
struct mac_esp_priv *mep = MAC_ESP_GET_PRIV(esp);
int i = 500000;
do {
esp->sreg = esp_read8(ESP_STATUS);
if (esp->sreg & ESP_STAT_INTR)
return 0;
udelay(2);
} while (--i);
printk(KERN_ERR PFX "IRQ timeout (sreg %02x)\n", esp->sreg);
mep->error = 1;
return 1;
}
#define MAC_ESP_PIO_LOOP(operands, reg1) \
asm volatile ( \
"1: moveb " operands " \n" \
" subqw #1,%1 \n" \
" jbne 1b \n" \
: "+a" (addr), "+r" (reg1) \
: "a" (fifo))
#define MAC_ESP_PIO_FILL(operands, reg1) \
asm volatile ( \
" moveb " operands " \n" \
" moveb " operands " \n" \
" moveb " operands " \n" \
" moveb " operands " \n" \
" moveb " operands " \n" \
" moveb " operands " \n" \
" moveb " operands " \n" \
" moveb " operands " \n" \
" moveb " operands " \n" \
" moveb " operands " \n" \
" moveb " operands " \n" \
" moveb " operands " \n" \
" moveb " operands " \n" \
" moveb " operands " \n" \
" moveb " operands " \n" \
" moveb " operands " \n" \
" subqw #8,%1 \n" \
" subqw #8,%1 \n" \
: "+a" (addr), "+r" (reg1) \
: "a" (fifo))
#define MAC_ESP_FIFO_SIZE 16
static void mac_esp_send_pio_cmd(struct esp *esp, u32 addr, u32 esp_count,
u32 dma_count, int write, u8 cmd)
{
struct mac_esp_priv *mep = MAC_ESP_GET_PRIV(esp);
u8 *fifo = esp->regs + ESP_FDATA * 16;
disable_irq(esp->host->irq);
cmd &= ~ESP_CMD_DMA;
mep->error = 0;
if (write) {
scsi_esp_cmd(esp, cmd);
while (1) {
unsigned int n;
n = mac_esp_wait_for_fifo(esp);
if (!n)
break;
if (n > esp_count)
n = esp_count;
esp_count -= n;
MAC_ESP_PIO_LOOP("%2@,%0@+", n);
if (!esp_count)
break;
if (mac_esp_wait_for_intr(esp))
break;
if (((esp->sreg & ESP_STAT_PMASK) != ESP_DIP) &&
((esp->sreg & ESP_STAT_PMASK) != ESP_MIP))
break;
esp->ireg = esp_read8(ESP_INTRPT);
if ((esp->ireg & (ESP_INTR_DC | ESP_INTR_BSERV)) !=
ESP_INTR_BSERV)
break;
scsi_esp_cmd(esp, ESP_CMD_TI);
}
} else {
scsi_esp_cmd(esp, ESP_CMD_FLUSH);
if (esp_count >= MAC_ESP_FIFO_SIZE)
MAC_ESP_PIO_FILL("%0@+,%2@", esp_count);
else
MAC_ESP_PIO_LOOP("%0@+,%2@", esp_count);
scsi_esp_cmd(esp, cmd);
while (esp_count) {
unsigned int n;
if (mac_esp_wait_for_intr(esp))
break;
if (((esp->sreg & ESP_STAT_PMASK) != ESP_DOP) &&
((esp->sreg & ESP_STAT_PMASK) != ESP_MOP))
break;
esp->ireg = esp_read8(ESP_INTRPT);
if ((esp->ireg & (ESP_INTR_DC | ESP_INTR_BSERV)) !=
ESP_INTR_BSERV)
break;
n = MAC_ESP_FIFO_SIZE -
(esp_read8(ESP_FFLAGS) & ESP_FF_FBYTES);
if (n > esp_count)
n = esp_count;
if (n == MAC_ESP_FIFO_SIZE) {
MAC_ESP_PIO_FILL("%0@+,%2@", esp_count);
} else {
esp_count -= n;
MAC_ESP_PIO_LOOP("%0@+,%2@", n);
}
scsi_esp_cmd(esp, ESP_CMD_TI);
}
}
enable_irq(esp->host->irq);
}
static int mac_esp_irq_pending(struct esp *esp)
{
if (esp_read8(ESP_STATUS) & ESP_STAT_INTR)
return 1;
return 0;
}
static u32 mac_esp_dma_length_limit(struct esp *esp, u32 dma_addr, u32 dma_len)
{
return dma_len > 0xFFFF ? 0xFFFF : dma_len;
}
static irqreturn_t mac_scsi_esp_intr(int irq, void *dev_id)
{
int got_intr;
/*
* This is an edge triggered IRQ, so we have to be careful to
* avoid missing a transition when it is shared by two ESP devices.
*/
do {
got_intr = 0;
if (esp_chips[0] &&
(mac_esp_read8(esp_chips[0], ESP_STATUS) & ESP_STAT_INTR)) {
(void)scsi_esp_intr(irq, esp_chips[0]);
got_intr = 1;
}
if (esp_chips[1] &&
(mac_esp_read8(esp_chips[1], ESP_STATUS) & ESP_STAT_INTR)) {
(void)scsi_esp_intr(irq, esp_chips[1]);
got_intr = 1;
}
} while (got_intr);
return IRQ_HANDLED;
}
static struct esp_driver_ops mac_esp_ops = {
.esp_write8 = mac_esp_write8,
.esp_read8 = mac_esp_read8,
.map_single = mac_esp_map_single,
.map_sg = mac_esp_map_sg,
.unmap_single = mac_esp_unmap_single,
.unmap_sg = mac_esp_unmap_sg,
.irq_pending = mac_esp_irq_pending,
.dma_length_limit = mac_esp_dma_length_limit,
.reset_dma = mac_esp_reset_dma,
.dma_drain = mac_esp_dma_drain,
.dma_invalidate = mac_esp_dma_invalidate,
.send_dma_cmd = mac_esp_send_pdma_cmd,
.dma_error = mac_esp_dma_error,
};
static int __devinit esp_mac_probe(struct platform_device *dev)
{
struct scsi_host_template *tpnt = &scsi_esp_template;
struct Scsi_Host *host;
struct esp *esp;
int err;
int chips_present;
struct mac_esp_priv *mep;
if (!MACH_IS_MAC)
return -ENODEV;
switch (macintosh_config->scsi_type) {
case MAC_SCSI_QUADRA:
case MAC_SCSI_QUADRA3:
chips_present = 1;
break;
case MAC_SCSI_QUADRA2:
if ((macintosh_config->ident == MAC_MODEL_Q900) ||
(macintosh_config->ident == MAC_MODEL_Q950))
chips_present = 2;
else
chips_present = 1;
break;
default:
chips_present = 0;
}
if (dev->id + 1 > chips_present)
return -ENODEV;
host = scsi_host_alloc(tpnt, sizeof(struct esp));
err = -ENOMEM;
if (!host)
goto fail;
host->max_id = 8;
host->use_clustering = DISABLE_CLUSTERING;
esp = shost_priv(host);
esp->host = host;
esp->dev = dev;
esp->command_block = kzalloc(16, GFP_KERNEL);
if (!esp->command_block)
goto fail_unlink;
esp->command_block_dma = (dma_addr_t)esp->command_block;
esp->scsi_id = 7;
host->this_id = esp->scsi_id;
esp->scsi_id_mask = 1 << esp->scsi_id;
mep = kzalloc(sizeof(struct mac_esp_priv), GFP_KERNEL);
if (!mep)
goto fail_free_command_block;
mep->esp = esp;
platform_set_drvdata(dev, mep);
switch (macintosh_config->scsi_type) {
case MAC_SCSI_QUADRA:
esp->cfreq = 16500000;
esp->regs = (void __iomem *)MAC_ESP_REGS_QUADRA;
mep->pdma_io = esp->regs + MAC_ESP_PDMA_IO_OFFSET;
mep->pdma_regs = NULL;
break;
case MAC_SCSI_QUADRA2:
esp->cfreq = 25000000;
esp->regs = (void __iomem *)(MAC_ESP_REGS_QUADRA2 +
dev->id * MAC_ESP_REGS_SPACING);
mep->pdma_io = esp->regs + MAC_ESP_PDMA_IO_OFFSET;
mep->pdma_regs = (void __iomem *)(MAC_ESP_PDMA_REG +
dev->id * MAC_ESP_PDMA_REG_SPACING);
nubus_writel(0x1d1, mep->pdma_regs);
break;
case MAC_SCSI_QUADRA3:
/* These quadras have a real DMA controller (the PSC) but we
* don't know how to drive it so we must use PIO instead.
*/
esp->cfreq = 25000000;
esp->regs = (void __iomem *)MAC_ESP_REGS_QUADRA3;
mep->pdma_io = NULL;
mep->pdma_regs = NULL;
break;
}
esp->ops = &mac_esp_ops;
if (mep->pdma_io == NULL) {
printk(KERN_INFO PFX "using PIO for controller %d\n", dev->id);
esp_write8(0, ESP_TCLOW);
esp_write8(0, ESP_TCMED);
esp->flags = ESP_FLAG_DISABLE_SYNC;
mac_esp_ops.send_dma_cmd = mac_esp_send_pio_cmd;
} else {
printk(KERN_INFO PFX "using PDMA for controller %d\n", dev->id);
}
host->irq = IRQ_MAC_SCSI;
esp_chips[dev->id] = esp;
mb();
if (esp_chips[!dev->id] == NULL) {
err = request_irq(host->irq, mac_scsi_esp_intr, 0,
"Mac ESP", NULL);
if (err < 0) {
esp_chips[dev->id] = NULL;
goto fail_free_priv;
}
}
err = scsi_esp_register(esp, &dev->dev);
if (err)
goto fail_free_irq;
return 0;
fail_free_irq:
if (esp_chips[!dev->id] == NULL)
free_irq(host->irq, esp);
fail_free_priv:
kfree(mep);
fail_free_command_block:
kfree(esp->command_block);
fail_unlink:
scsi_host_put(host);
fail:
return err;
}
static int __devexit esp_mac_remove(struct platform_device *dev)
{
struct mac_esp_priv *mep = platform_get_drvdata(dev);
struct esp *esp = mep->esp;
unsigned int irq = esp->host->irq;
scsi_esp_unregister(esp);
esp_chips[dev->id] = NULL;
if (!(esp_chips[0] || esp_chips[1]))
free_irq(irq, NULL);
kfree(mep);
kfree(esp->command_block);
scsi_host_put(esp->host);
return 0;
}
static struct platform_driver esp_mac_driver = {
.probe = esp_mac_probe,
.remove = __devexit_p(esp_mac_remove),
.driver = {
.name = DRV_MODULE_NAME,
},
};
static int __init mac_esp_init(void)
{
int err;
err = platform_driver_register(&esp_mac_driver);
if (err)
return err;
internal_pdev = platform_device_alloc(DRV_MODULE_NAME, 0);
if (internal_pdev && platform_device_add(internal_pdev)) {
platform_device_put(internal_pdev);
internal_pdev = NULL;
}
external_pdev = platform_device_alloc(DRV_MODULE_NAME, 1);
if (external_pdev && platform_device_add(external_pdev)) {
platform_device_put(external_pdev);
external_pdev = NULL;
}
if (internal_pdev || external_pdev) {
return 0;
} else {
platform_driver_unregister(&esp_mac_driver);
return -ENOMEM;
}
}
static void __exit mac_esp_exit(void)
{
platform_driver_unregister(&esp_mac_driver);
if (internal_pdev) {
platform_device_unregister(internal_pdev);
internal_pdev = NULL;
}
if (external_pdev) {
platform_device_unregister(external_pdev);
external_pdev = NULL;
}
}
MODULE_DESCRIPTION("Mac ESP SCSI driver");
MODULE_AUTHOR("Finn Thain <fthain@telegraphics.com.au>");
MODULE_LICENSE("GPL v2");
MODULE_VERSION(DRV_VERSION);
module_init(mac_esp_init);
module_exit(mac_esp_exit);
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