linux/drivers/sbus/char/jsflash.c
Tejun Heo 9934c8c045 block: implement and enforce request peek/start/fetch
Till now block layer allowed two separate modes of request execution.
A request is always acquired from the request queue via
elv_next_request().  After that, drivers are free to either dequeue it
or process it without dequeueing.  Dequeue allows elv_next_request()
to return the next request so that multiple requests can be in flight.

Executing requests without dequeueing has its merits mostly in
allowing drivers for simpler devices which can't do sg to deal with
segments only without considering request boundary.  However, the
benefit this brings is dubious and declining while the cost of the API
ambiguity is increasing.  Segment based drivers are usually for very
old or limited devices and as converting to dequeueing model isn't
difficult, it doesn't justify the API overhead it puts on block layer
and its more modern users.

Previous patches converted all block low level drivers to dequeueing
model.  This patch completes the API transition by...

* renaming elv_next_request() to blk_peek_request()

* renaming blkdev_dequeue_request() to blk_start_request()

* adding blk_fetch_request() which is combination of peek and start

* disallowing completion of queued (not started) requests

* applying new API to all LLDs

Renamings are for consistency and to break out of tree code so that
it's apparent that out of tree drivers need updating.

[ Impact: block request issue API cleanup, no functional change ]

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: James Bottomley <James.Bottomley@HansenPartnership.com>
Cc: Mike Miller <mike.miller@hp.com>
Cc: unsik Kim <donari75@gmail.com>
Cc: Paul Clements <paul.clements@steeleye.com>
Cc: Tim Waugh <tim@cyberelk.net>
Cc: Geert Uytterhoeven <Geert.Uytterhoeven@sonycom.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: Laurent Vivier <Laurent@lvivier.info>
Cc: Jeff Garzik <jgarzik@pobox.com>
Cc: Jeremy Fitzhardinge <jeremy@xensource.com>
Cc: Grant Likely <grant.likely@secretlab.ca>
Cc: Adrian McMenamin <adrian@mcmen.demon.co.uk>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
Cc: Borislav Petkov <petkovbb@googlemail.com>
Cc: Sergei Shtylyov <sshtylyov@ru.mvista.com>
Cc: Alex Dubov <oakad@yahoo.com>
Cc: Pierre Ossman <drzeus@drzeus.cx>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Markus Lidel <Markus.Lidel@shadowconnect.com>
Cc: Stefan Weinhuber <wein@de.ibm.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Pete Zaitcev <zaitcev@redhat.com>
Cc: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2009-05-11 09:52:18 +02:00

635 lines
14 KiB
C

/*
* drivers/sbus/char/jsflash.c
*
* Copyright (C) 1991, 1992 Linus Torvalds (drivers/char/mem.c)
* Copyright (C) 1997 Eddie C. Dost (drivers/sbus/char/flash.c)
* Copyright (C) 1997-2000 Pavel Machek <pavel@ucw.cz> (drivers/block/nbd.c)
* Copyright (C) 1999-2000 Pete Zaitcev
*
* This driver is used to program OS into a Flash SIMM on
* Krups and Espresso platforms.
*
* TODO: do not allow erase/programming if file systems are mounted.
* TODO: Erase/program both banks of a 8MB SIMM.
*
* It is anticipated that programming an OS Flash will be a routine
* procedure. In the same time it is exeedingly dangerous because
* a user can program its OBP flash with OS image and effectively
* kill the machine.
*
* This driver uses an interface different from Eddie's flash.c
* as a silly safeguard.
*
* XXX The flash.c manipulates page caching characteristics in a certain
* dubious way; also it assumes that remap_pfn_range() can remap
* PCI bus locations, which may be false. ioremap() must be used
* instead. We should discuss this.
*/
#include <linux/module.h>
#include <linux/smp_lock.h>
#include <linux/types.h>
#include <linux/errno.h>
#include <linux/miscdevice.h>
#include <linux/slab.h>
#include <linux/fcntl.h>
#include <linux/poll.h>
#include <linux/init.h>
#include <linux/string.h>
#include <linux/genhd.h>
#include <linux/blkdev.h>
#include <asm/uaccess.h>
#include <asm/pgtable.h>
#include <asm/io.h>
#include <asm/pcic.h>
#include <asm/oplib.h>
#include <asm/jsflash.h> /* ioctl arguments. <linux/> ?? */
#define JSFIDSZ (sizeof(struct jsflash_ident_arg))
#define JSFPRGSZ (sizeof(struct jsflash_program_arg))
/*
* Our device numbers have no business in system headers.
* The only thing a user knows is the device name /dev/jsflash.
*
* Block devices are laid out like this:
* minor+0 - Bootstrap, for 8MB SIMM 0x20400000[0x800000]
* minor+1 - Filesystem to mount, normally 0x20400400[0x7ffc00]
* minor+2 - Whole flash area for any case... 0x20000000[0x01000000]
* Total 3 minors per flash device.
*
* It is easier to have static size vectors, so we define
* a total minor range JSF_MAX, which must cover all minors.
*/
/* character device */
#define JSF_MINOR 178 /* 178 is registered with hpa */
/* block device */
#define JSF_MAX 3 /* 3 minors wasted total so far. */
#define JSF_NPART 3 /* 3 minors per flash device */
#define JSF_PART_BITS 2 /* 2 bits of minors to cover JSF_NPART */
#define JSF_PART_MASK 0x3 /* 2 bits mask */
/*
* Access functions.
* We could ioremap(), but it's easier this way.
*/
static unsigned int jsf_inl(unsigned long addr)
{
unsigned long retval;
__asm__ __volatile__("lda [%1] %2, %0\n\t" :
"=r" (retval) :
"r" (addr), "i" (ASI_M_BYPASS));
return retval;
}
static void jsf_outl(unsigned long addr, __u32 data)
{
__asm__ __volatile__("sta %0, [%1] %2\n\t" : :
"r" (data), "r" (addr), "i" (ASI_M_BYPASS) :
"memory");
}
/*
* soft carrier
*/
struct jsfd_part {
unsigned long dbase;
unsigned long dsize;
};
struct jsflash {
unsigned long base;
unsigned long size;
unsigned long busy; /* In use? */
struct jsflash_ident_arg id;
/* int mbase; */ /* Minor base, typically zero */
struct jsfd_part dv[JSF_NPART];
};
/*
* We do not map normal memory or obio as a safety precaution.
* But offsets are real, for ease of userland programming.
*/
#define JSF_BASE_TOP 0x30000000
#define JSF_BASE_ALL 0x20000000
#define JSF_BASE_JK 0x20400000
/*
*/
static struct gendisk *jsfd_disk[JSF_MAX];
/*
* Let's pretend we may have several of these...
*/
static struct jsflash jsf0;
/*
* Wait for AMD to finish its embedded algorithm.
* We use the Toggle bit DQ6 (0x40) because it does not
* depend on the data value as /DATA bit DQ7 does.
*
* XXX Do we need any timeout here? So far it never hanged, beware broken hw.
*/
static void jsf_wait(unsigned long p) {
unsigned int x1, x2;
for (;;) {
x1 = jsf_inl(p);
x2 = jsf_inl(p);
if ((x1 & 0x40404040) == (x2 & 0x40404040)) return;
}
}
/*
* Programming will only work if Flash is clean,
* we leave it to the programmer application.
*
* AMD must be programmed one byte at a time;
* thus, Simple Tech SIMM must be written 4 bytes at a time.
*
* Write waits for the chip to become ready after the write
* was finished. This is done so that application would read
* consistent data after the write is done.
*/
static void jsf_write4(unsigned long fa, u32 data) {
jsf_outl(fa, 0xAAAAAAAA); /* Unlock 1 Write 1 */
jsf_outl(fa, 0x55555555); /* Unlock 1 Write 2 */
jsf_outl(fa, 0xA0A0A0A0); /* Byte Program */
jsf_outl(fa, data);
jsf_wait(fa);
}
/*
*/
static void jsfd_read(char *buf, unsigned long p, size_t togo) {
union byte4 {
char s[4];
unsigned int n;
} b;
while (togo >= 4) {
togo -= 4;
b.n = jsf_inl(p);
memcpy(buf, b.s, 4);
p += 4;
buf += 4;
}
}
static void jsfd_do_request(struct request_queue *q)
{
struct request *req;
req = blk_fetch_request(q);
while (req) {
struct jsfd_part *jdp = req->rq_disk->private_data;
unsigned long offset = blk_rq_pos(req) << 9;
size_t len = blk_rq_cur_bytes(req);
int err = -EIO;
if ((offset + len) > jdp->dsize)
goto end;
if (rq_data_dir(req) != READ) {
printk(KERN_ERR "jsfd: write\n");
goto end;
}
if ((jdp->dbase & 0xff000000) != 0x20000000) {
printk(KERN_ERR "jsfd: bad base %x\n", (int)jdp->dbase);
goto end;
}
jsfd_read(req->buffer, jdp->dbase + offset, len);
err = 0;
end:
if (!__blk_end_request_cur(req, err))
req = blk_fetch_request(q);
}
}
/*
* The memory devices use the full 32/64 bits of the offset, and so we cannot
* check against negative addresses: they are ok. The return value is weird,
* though, in that case (0).
*
* also note that seeking relative to the "end of file" isn't supported:
* it has no meaning, so it returns -EINVAL.
*/
static loff_t jsf_lseek(struct file * file, loff_t offset, int orig)
{
loff_t ret;
lock_kernel();
switch (orig) {
case 0:
file->f_pos = offset;
ret = file->f_pos;
break;
case 1:
file->f_pos += offset;
ret = file->f_pos;
break;
default:
ret = -EINVAL;
}
unlock_kernel();
return ret;
}
/*
* OS SIMM Cannot be read in other size but a 32bits word.
*/
static ssize_t jsf_read(struct file * file, char __user * buf,
size_t togo, loff_t *ppos)
{
unsigned long p = *ppos;
char __user *tmp = buf;
union byte4 {
char s[4];
unsigned int n;
} b;
if (p < JSF_BASE_ALL || p >= JSF_BASE_TOP) {
return 0;
}
if ((p + togo) < p /* wrap */
|| (p + togo) >= JSF_BASE_TOP) {
togo = JSF_BASE_TOP - p;
}
if (p < JSF_BASE_ALL && togo != 0) {
#if 0 /* __bzero XXX */
size_t x = JSF_BASE_ALL - p;
if (x > togo) x = togo;
clear_user(tmp, x);
tmp += x;
p += x;
togo -= x;
#else
/*
* Implementation of clear_user() calls __bzero
* without regard to modversions,
* so we cannot build a module.
*/
return 0;
#endif
}
while (togo >= 4) {
togo -= 4;
b.n = jsf_inl(p);
if (copy_to_user(tmp, b.s, 4))
return -EFAULT;
tmp += 4;
p += 4;
}
/*
* XXX Small togo may remain if 1 byte is ordered.
* It would be nice if we did a word size read and unpacked it.
*/
*ppos = p;
return tmp-buf;
}
static ssize_t jsf_write(struct file * file, const char __user * buf,
size_t count, loff_t *ppos)
{
return -ENOSPC;
}
/*
*/
static int jsf_ioctl_erase(unsigned long arg)
{
unsigned long p;
/* p = jsf0.base; hits wrong bank */
p = 0x20400000;
jsf_outl(p, 0xAAAAAAAA); /* Unlock 1 Write 1 */
jsf_outl(p, 0x55555555); /* Unlock 1 Write 2 */
jsf_outl(p, 0x80808080); /* Erase setup */
jsf_outl(p, 0xAAAAAAAA); /* Unlock 2 Write 1 */
jsf_outl(p, 0x55555555); /* Unlock 2 Write 2 */
jsf_outl(p, 0x10101010); /* Chip erase */
#if 0
/*
* This code is ok, except that counter based timeout
* has no place in this world. Let's just drop timeouts...
*/
{
int i;
__u32 x;
for (i = 0; i < 1000000; i++) {
x = jsf_inl(p);
if ((x & 0x80808080) == 0x80808080) break;
}
if ((x & 0x80808080) != 0x80808080) {
printk("jsf0: erase timeout with 0x%08x\n", x);
} else {
printk("jsf0: erase done with 0x%08x\n", x);
}
}
#else
jsf_wait(p);
#endif
return 0;
}
/*
* Program a block of flash.
* Very simple because we can do it byte by byte anyway.
*/
static int jsf_ioctl_program(void __user *arg)
{
struct jsflash_program_arg abuf;
char __user *uptr;
unsigned long p;
unsigned int togo;
union {
unsigned int n;
char s[4];
} b;
if (copy_from_user(&abuf, arg, JSFPRGSZ))
return -EFAULT;
p = abuf.off;
togo = abuf.size;
if ((togo & 3) || (p & 3)) return -EINVAL;
uptr = (char __user *) (unsigned long) abuf.data;
while (togo != 0) {
togo -= 4;
if (copy_from_user(&b.s[0], uptr, 4))
return -EFAULT;
jsf_write4(p, b.n);
p += 4;
uptr += 4;
}
return 0;
}
static long jsf_ioctl(struct file *f, unsigned int cmd, unsigned long arg)
{
lock_kernel();
int error = -ENOTTY;
void __user *argp = (void __user *)arg;
if (!capable(CAP_SYS_ADMIN)) {
unlock_kernel();
return -EPERM;
}
switch (cmd) {
case JSFLASH_IDENT:
if (copy_to_user(argp, &jsf0.id, JSFIDSZ)) {
unlock_kernel();
return -EFAULT;
}
break;
case JSFLASH_ERASE:
error = jsf_ioctl_erase(arg);
break;
case JSFLASH_PROGRAM:
error = jsf_ioctl_program(argp);
break;
}
unlock_kernel();
return error;
}
static int jsf_mmap(struct file * file, struct vm_area_struct * vma)
{
return -ENXIO;
}
static int jsf_open(struct inode * inode, struct file * filp)
{
lock_kernel();
if (jsf0.base == 0) {
unlock_kernel();
return -ENXIO;
}
if (test_and_set_bit(0, (void *)&jsf0.busy) != 0) {
unlock_kernel();
return -EBUSY;
}
unlock_kernel();
return 0; /* XXX What security? */
}
static int jsf_release(struct inode *inode, struct file *file)
{
jsf0.busy = 0;
return 0;
}
static const struct file_operations jsf_fops = {
.owner = THIS_MODULE,
.llseek = jsf_lseek,
.read = jsf_read,
.write = jsf_write,
.unlocked_ioctl = jsf_ioctl,
.mmap = jsf_mmap,
.open = jsf_open,
.release = jsf_release,
};
static struct miscdevice jsf_dev = { JSF_MINOR, "jsflash", &jsf_fops };
static struct block_device_operations jsfd_fops = {
.owner = THIS_MODULE,
};
static int jsflash_init(void)
{
int rc;
struct jsflash *jsf;
int node;
char banner[128];
struct linux_prom_registers reg0;
node = prom_getchild(prom_root_node);
node = prom_searchsiblings(node, "flash-memory");
if (node != 0 && node != -1) {
if (prom_getproperty(node, "reg",
(char *)&reg0, sizeof(reg0)) == -1) {
printk("jsflash: no \"reg\" property\n");
return -ENXIO;
}
if (reg0.which_io != 0) {
printk("jsflash: bus number nonzero: 0x%x:%x\n",
reg0.which_io, reg0.phys_addr);
return -ENXIO;
}
/*
* Flash may be somewhere else, for instance on Ebus.
* So, don't do the following check for IIep flash space.
*/
#if 0
if ((reg0.phys_addr >> 24) != 0x20) {
printk("jsflash: suspicious address: 0x%x:%x\n",
reg0.which_io, reg0.phys_addr);
return -ENXIO;
}
#endif
if ((int)reg0.reg_size <= 0) {
printk("jsflash: bad size 0x%x\n", (int)reg0.reg_size);
return -ENXIO;
}
} else {
/* XXX Remove this code once PROLL ID12 got widespread */
printk("jsflash: no /flash-memory node, use PROLL >= 12\n");
prom_getproperty(prom_root_node, "banner-name", banner, 128);
if (strcmp (banner, "JavaStation-NC") != 0 &&
strcmp (banner, "JavaStation-E") != 0) {
return -ENXIO;
}
reg0.which_io = 0;
reg0.phys_addr = 0x20400000;
reg0.reg_size = 0x00800000;
}
/* Let us be really paranoid for modifications to probing code. */
/* extern enum sparc_cpu sparc_cpu_model; */ /* in <asm/system.h> */
if (sparc_cpu_model != sun4m) {
/* We must be on sun4m because we use MMU Bypass ASI. */
return -ENXIO;
}
if (jsf0.base == 0) {
jsf = &jsf0;
jsf->base = reg0.phys_addr;
jsf->size = reg0.reg_size;
/* XXX Redo the userland interface. */
jsf->id.off = JSF_BASE_ALL;
jsf->id.size = 0x01000000; /* 16M - all segments */
strcpy(jsf->id.name, "Krups_all");
jsf->dv[0].dbase = jsf->base;
jsf->dv[0].dsize = jsf->size;
jsf->dv[1].dbase = jsf->base + 1024;
jsf->dv[1].dsize = jsf->size - 1024;
jsf->dv[2].dbase = JSF_BASE_ALL;
jsf->dv[2].dsize = 0x01000000;
printk("Espresso Flash @0x%lx [%d MB]\n", jsf->base,
(int) (jsf->size / (1024*1024)));
}
if ((rc = misc_register(&jsf_dev)) != 0) {
printk(KERN_ERR "jsf: unable to get misc minor %d\n",
JSF_MINOR);
jsf0.base = 0;
return rc;
}
return 0;
}
static struct request_queue *jsf_queue;
static int jsfd_init(void)
{
static DEFINE_SPINLOCK(lock);
struct jsflash *jsf;
struct jsfd_part *jdp;
int err;
int i;
if (jsf0.base == 0)
return -ENXIO;
err = -ENOMEM;
for (i = 0; i < JSF_MAX; i++) {
struct gendisk *disk = alloc_disk(1);
if (!disk)
goto out;
jsfd_disk[i] = disk;
}
if (register_blkdev(JSFD_MAJOR, "jsfd")) {
err = -EIO;
goto out;
}
jsf_queue = blk_init_queue(jsfd_do_request, &lock);
if (!jsf_queue) {
err = -ENOMEM;
unregister_blkdev(JSFD_MAJOR, "jsfd");
goto out;
}
for (i = 0; i < JSF_MAX; i++) {
struct gendisk *disk = jsfd_disk[i];
if ((i & JSF_PART_MASK) >= JSF_NPART) continue;
jsf = &jsf0; /* actually, &jsfv[i >> JSF_PART_BITS] */
jdp = &jsf->dv[i&JSF_PART_MASK];
disk->major = JSFD_MAJOR;
disk->first_minor = i;
sprintf(disk->disk_name, "jsfd%d", i);
disk->fops = &jsfd_fops;
set_capacity(disk, jdp->dsize >> 9);
disk->private_data = jdp;
disk->queue = jsf_queue;
add_disk(disk);
set_disk_ro(disk, 1);
}
return 0;
out:
while (i--)
put_disk(jsfd_disk[i]);
return err;
}
MODULE_LICENSE("GPL");
static int __init jsflash_init_module(void) {
int rc;
if ((rc = jsflash_init()) == 0) {
jsfd_init();
return 0;
}
return rc;
}
static void __exit jsflash_cleanup_module(void)
{
int i;
for (i = 0; i < JSF_MAX; i++) {
if ((i & JSF_PART_MASK) >= JSF_NPART) continue;
del_gendisk(jsfd_disk[i]);
put_disk(jsfd_disk[i]);
}
if (jsf0.busy)
printk("jsf0: cleaning busy unit\n");
jsf0.base = 0;
jsf0.busy = 0;
misc_deregister(&jsf_dev);
unregister_blkdev(JSFD_MAJOR, "jsfd");
blk_cleanup_queue(jsf_queue);
}
module_init(jsflash_init_module);
module_exit(jsflash_cleanup_module);