linux/drivers/zorro/zorro.c
Geert Uytterhoeven a7f4d00a82 zorro: Defer device_register() until all devices have been identified
As the Amiga Zorro II address space is limited to 8.5 MiB and Zorro
devices can contain only one BAR, several Amiga Zorro II expansion
boards (mainly graphics cards) contain multiple Zorro devices: a small
one for the control registers and one (or more) for the graphics memory.

The conversion of cirrusfb to the new driver framework introduced a
regression: the driver contains a zorro_driver for the first Zorro
device, and uses the (old) zorro_find_device() call to find the second
Zorro device.

However, as the Zorro core calls device_register() as soon as a Zorro
device is identified, it may not have identified the second Zorro device
belonging to the same physical Zorro expansion card.  Hence cirrusfb
could no longer find the second part of the Picasso II graphics card,
causing a NULL pointer dereference.

Defer the registration of Zorro devices with the driver framework until
all Zorro devices have been identified to fix this.

Note that the alternative solution (modifying cirrusfb to register a
zorro_driver for all Zorro devices belonging to a graphics card, instead
of only for the first one, and adding a synchronization mechanism to
defer initialization until all have been found), is not an option, as on
some cards one device may be optional (e.g.  the second bank of 2 MiB of
graphics memory on the Picasso IV in Zorro II mode).

Reported-by: Ingo Jürgensmann <ij@2011.bluespice.org>
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: stable@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-09-22 12:59:35 -07:00

223 lines
5.1 KiB
C

/*
* Zorro Bus Services
*
* Copyright (C) 1995-2003 Geert Uytterhoeven
*
* This file is subject to the terms and conditions of the GNU General Public
* License. See the file COPYING in the main directory of this archive
* for more details.
*/
#include <linux/module.h>
#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/zorro.h>
#include <linux/bitops.h>
#include <linux/string.h>
#include <linux/platform_device.h>
#include <linux/slab.h>
#include <asm/setup.h>
#include <asm/amigahw.h>
#include "zorro.h"
/*
* Zorro Expansion Devices
*/
unsigned int zorro_num_autocon;
struct zorro_dev zorro_autocon[ZORRO_NUM_AUTO];
/*
* Zorro bus
*/
struct zorro_bus {
struct list_head devices; /* list of devices on this bus */
struct device dev;
};
/*
* Find Zorro Devices
*/
struct zorro_dev *zorro_find_device(zorro_id id, struct zorro_dev *from)
{
struct zorro_dev *z;
if (!zorro_num_autocon)
return NULL;
for (z = from ? from+1 : &zorro_autocon[0];
z < zorro_autocon+zorro_num_autocon;
z++)
if (id == ZORRO_WILDCARD || id == z->id)
return z;
return NULL;
}
EXPORT_SYMBOL(zorro_find_device);
/*
* Bitmask indicating portions of available Zorro II RAM that are unused
* by the system. Every bit represents a 64K chunk, for a maximum of 8MB
* (128 chunks, physical 0x00200000-0x009fffff).
*
* If you want to use (= allocate) portions of this RAM, you should clear
* the corresponding bits.
*
* Possible uses:
* - z2ram device
* - SCSI DMA bounce buffers
*
* FIXME: use the normal resource management
*/
DECLARE_BITMAP(zorro_unused_z2ram, 128);
EXPORT_SYMBOL(zorro_unused_z2ram);
static void __init mark_region(unsigned long start, unsigned long end,
int flag)
{
if (flag)
start += Z2RAM_CHUNKMASK;
else
end += Z2RAM_CHUNKMASK;
start &= ~Z2RAM_CHUNKMASK;
end &= ~Z2RAM_CHUNKMASK;
if (end <= Z2RAM_START || start >= Z2RAM_END)
return;
start = start < Z2RAM_START ? 0x00000000 : start-Z2RAM_START;
end = end > Z2RAM_END ? Z2RAM_SIZE : end-Z2RAM_START;
while (start < end) {
u32 chunk = start>>Z2RAM_CHUNKSHIFT;
if (flag)
set_bit(chunk, zorro_unused_z2ram);
else
clear_bit(chunk, zorro_unused_z2ram);
start += Z2RAM_CHUNKSIZE;
}
}
static struct resource __init *zorro_find_parent_resource(
struct platform_device *bridge, struct zorro_dev *z)
{
int i;
for (i = 0; i < bridge->num_resources; i++) {
struct resource *r = &bridge->resource[i];
if (zorro_resource_start(z) >= r->start &&
zorro_resource_end(z) <= r->end)
return r;
}
return &iomem_resource;
}
static int __init amiga_zorro_probe(struct platform_device *pdev)
{
struct zorro_bus *bus;
struct zorro_dev *z;
struct resource *r;
unsigned int i;
int error;
/* Initialize the Zorro bus */
bus = kzalloc(sizeof(*bus), GFP_KERNEL);
if (!bus)
return -ENOMEM;
INIT_LIST_HEAD(&bus->devices);
bus->dev.parent = &pdev->dev;
dev_set_name(&bus->dev, "zorro");
error = device_register(&bus->dev);
if (error) {
pr_err("Zorro: Error registering zorro_bus\n");
put_device(&bus->dev);
kfree(bus);
return error;
}
platform_set_drvdata(pdev, bus);
pr_info("Zorro: Probing AutoConfig expansion devices: %u device%s\n",
zorro_num_autocon, zorro_num_autocon == 1 ? "" : "s");
/* First identify all devices ... */
for (i = 0; i < zorro_num_autocon; i++) {
z = &zorro_autocon[i];
z->id = (z->rom.er_Manufacturer<<16) | (z->rom.er_Product<<8);
if (z->id == ZORRO_PROD_GVP_EPC_BASE) {
/* GVP quirk */
unsigned long magic = zorro_resource_start(z)+0x8000;
z->id |= *(u16 *)ZTWO_VADDR(magic) & GVP_PRODMASK;
}
sprintf(z->name, "Zorro device %08x", z->id);
zorro_name_device(z);
z->resource.name = z->name;
r = zorro_find_parent_resource(pdev, z);
error = request_resource(r, &z->resource);
if (error)
dev_err(&bus->dev,
"Address space collision on device %s %pR\n",
z->name, &z->resource);
dev_set_name(&z->dev, "%02x", i);
z->dev.parent = &bus->dev;
z->dev.bus = &zorro_bus_type;
}
/* ... then register them */
for (i = 0; i < zorro_num_autocon; i++) {
z = &zorro_autocon[i];
error = device_register(&z->dev);
if (error) {
dev_err(&bus->dev, "Error registering device %s\n",
z->name);
put_device(&z->dev);
continue;
}
error = zorro_create_sysfs_dev_files(z);
if (error)
dev_err(&z->dev, "Error creating sysfs files\n");
}
/* Mark all available Zorro II memory */
zorro_for_each_dev(z) {
if (z->rom.er_Type & ERTF_MEMLIST)
mark_region(zorro_resource_start(z),
zorro_resource_end(z)+1, 1);
}
/* Unmark all used Zorro II memory */
for (i = 0; i < m68k_num_memory; i++)
if (m68k_memory[i].addr < 16*1024*1024)
mark_region(m68k_memory[i].addr,
m68k_memory[i].addr+m68k_memory[i].size,
0);
return 0;
}
static struct platform_driver amiga_zorro_driver = {
.driver = {
.name = "amiga-zorro",
.owner = THIS_MODULE,
},
};
static int __init amiga_zorro_init(void)
{
return platform_driver_probe(&amiga_zorro_driver, amiga_zorro_probe);
}
module_init(amiga_zorro_init);
MODULE_LICENSE("GPL");