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linux/drivers/scsi/mac_esp.c
Uwe Kleine-König 0b649224f7 scsi: mac_esp: Convert to platform remove callback returning void 
The .remove() callback for a platform driver returns an int which makes
many driver authors wrongly assume it's possible to do error handling by
returning an error code. However the value returned is ignored (apart
from emitting a warning) and this typically results in resource leaks.

To improve here there is a quest to make the remove callback return
void. In the first step of this quest all drivers are converted to
.remove_new(), which already returns void. Eventually after all drivers
are converted, .remove_new() will be renamed to .remove().

In the error path emit an error message replacing the (less useful)
message by the core. Apart from the improved error message there is no
change in behaviour.

Trivially convert this driver from always returning zero in the remove
callback to the void returning variant.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Link: https://lore.kernel.org/r/9013c84059b8ccd6a5c8305aa35cfdfa314ba74c.1701619134.git.u.kleine-koenig@pengutronix.de
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2023-12-05 21:51:37 -05:00

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// SPDX-License-Identifier: GPL-2.0-only
/* 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 <linux/slab.h>
#include <asm/irq.h>
#include <asm/dma.h>
#include <asm/macints.h>
#include <asm/macintosh.h>
#include <asm/mac_via.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;
};
static struct esp *esp_chips[2];
static DEFINE_SPINLOCK(esp_chips_lock);
#define MAC_ESP_GET_PRIV(esp) ((struct mac_esp_priv *) \
dev_get_drvdata((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);
}
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 esp->send_cmd_error;
}
static inline int mac_esp_wait_for_empty_fifo(struct esp *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));
esp->send_cmd_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 (via2_scsi_drq_pending())
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));
esp->send_cmd_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);
esp->send_cmd_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);
}
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,
.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 esp_mac_probe(struct platform_device *dev)
{
const struct scsi_host_template *tpnt = &scsi_esp_template;
struct Scsi_Host *host;
struct esp *esp;
int err;
struct mac_esp_priv *mep;
if (!MACH_IS_MAC)
return -ENODEV;
if (dev->id > 1)
return -ENODEV;
host = scsi_host_alloc(tpnt, sizeof(struct esp));
err = -ENOMEM;
if (!host)
goto fail;
host->max_id = 8;
host->dma_boundary = PAGE_SIZE - 1;
esp = shost_priv(host);
esp->host = host;
esp->dev = &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->fifo_reg = esp->regs + ESP_FDATA * 16;
esp->ops = &mac_esp_ops;
esp->flags = ESP_FLAG_NO_DMA_MAP;
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 = esp_send_pio_cmd;
} else {
printk(KERN_INFO PFX "using PDMA for controller %d\n", dev->id);
}
host->irq = IRQ_MAC_SCSI;
/* The request_irq() call is intended to succeed for the first device
* and fail for the second device.
*/
err = request_irq(host->irq, mac_scsi_esp_intr, 0, "ESP", NULL);
spin_lock(&esp_chips_lock);
if (err < 0 && esp_chips[!dev->id] == NULL) {
spin_unlock(&esp_chips_lock);
goto fail_free_priv;
}
esp_chips[dev->id] = esp;
spin_unlock(&esp_chips_lock);
err = scsi_esp_register(esp);
if (err)
goto fail_free_irq;
return 0;
fail_free_irq:
spin_lock(&esp_chips_lock);
esp_chips[dev->id] = NULL;
if (esp_chips[!dev->id] == NULL) {
spin_unlock(&esp_chips_lock);
free_irq(host->irq, NULL);
} else
spin_unlock(&esp_chips_lock);
fail_free_priv:
kfree(mep);
fail_free_command_block:
kfree(esp->command_block);
fail_unlink:
scsi_host_put(host);
fail:
return err;
}
static void 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);
spin_lock(&esp_chips_lock);
esp_chips[dev->id] = NULL;
if (esp_chips[!dev->id] == NULL) {
spin_unlock(&esp_chips_lock);
free_irq(irq, NULL);
} else
spin_unlock(&esp_chips_lock);
kfree(mep);
kfree(esp->command_block);
scsi_host_put(esp->host);
}
static struct platform_driver esp_mac_driver = {
.probe = esp_mac_probe,
.remove_new = esp_mac_remove,
.driver = {
.name = DRV_MODULE_NAME,
},
};
module_platform_driver(esp_mac_driver);
MODULE_DESCRIPTION("Mac ESP SCSI driver");
MODULE_AUTHOR("Finn Thain");
MODULE_LICENSE("GPL v2");
MODULE_VERSION(DRV_VERSION);
MODULE_ALIAS("platform:" DRV_MODULE_NAME);
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