linux/drivers/zorro/zorro.c
Gustavo A. R. Silva 573a73abc3 zorro: Replace zero-length array with flexible-array member
The current codebase makes use of the zero-length array language
extension to the C90 standard, but the preferred mechanism to declare
variable-length types such as these ones is a flexible array member[1][2],
introduced in C99:

struct foo {
        int stuff;
        struct boo array[];
};

By making use of the mechanism above, we will get a compiler warning
in case the flexible array does not occur last in the structure, which
will help us prevent some kind of undefined behavior bugs from being
inadvertently introduced[3] to the codebase from now on.

Also, notice that, dynamic memory allocations won't be affected by
this change:

"Flexible array members have incomplete type, and so the sizeof operator
may not be applied. As a quirk of the original implementation of
zero-length arrays, sizeof evaluates to zero."[1]

This issue was found with the help of Coccinelle.

[1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html
[2] https://github.com/KSPP/linux/issues/21
[3] commit 7649773293 ("cxgb3/l2t: Fix undefined behaviour")

Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Link: https://lore.kernel.org/r/20200227183748.GA31018@embeddedor
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
2020-03-09 11:12:19 +01:00

247 lines
5.6 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/dma-mapping.h>
#include <linux/slab.h>
#include <asm/byteorder.h>
#include <asm/setup.h>
#include <asm/amigahw.h>
#include "zorro.h"
/*
* Zorro Expansion Devices
*/
unsigned int zorro_num_autocon;
struct zorro_dev_init zorro_autocon_init[ZORRO_NUM_AUTO] __initdata;
struct zorro_dev *zorro_autocon;
/*
* Zorro bus
*/
struct zorro_bus {
struct device dev;
struct zorro_dev devices[];
};
/*
* 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_init *zi;
struct zorro_dev *z;
struct resource *r;
unsigned int i;
int error;
/* Initialize the Zorro bus */
bus = kzalloc(struct_size(bus, devices, zorro_num_autocon),
GFP_KERNEL);
if (!bus)
return -ENOMEM;
zorro_autocon = bus->devices;
bus->dev.parent = &pdev->dev;
dev_set_name(&bus->dev, zorro_bus_type.name);
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++) {
zi = &zorro_autocon_init[i];
z = &zorro_autocon[i];
z->rom = zi->rom;
z->id = (be16_to_cpu(z->rom.er_Manufacturer) << 16) |
(z->rom.er_Product << 8);
if (z->id == ZORRO_PROD_GVP_EPC_BASE) {
/* GVP quirk */
unsigned long magic = zi->boardaddr + 0x8000;
z->id |= *(u16 *)ZTWO_VADDR(magic) & GVP_PRODMASK;
}
z->slotaddr = zi->slotaddr;
z->slotsize = zi->slotsize;
sprintf(z->name, "Zorro device %08x", z->id);
zorro_name_device(z);
z->resource.start = zi->boardaddr;
z->resource.end = zi->boardaddr + zi->boardsize - 1;
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);
z->dev.parent = &bus->dev;
z->dev.bus = &zorro_bus_type;
z->dev.id = i;
switch (z->rom.er_Type & ERT_TYPEMASK) {
case ERT_ZORROIII:
z->dev.coherent_dma_mask = DMA_BIT_MASK(32);
break;
case ERT_ZORROII:
default:
z->dev.coherent_dma_mask = DMA_BIT_MASK(24);
break;
}
z->dev.dma_mask = &z->dev.coherent_dma_mask;
}
/* ... 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;
}
}
/* 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",
},
};
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");