linuxdebug/drivers/mtd/maps/amd76xrom.c

349 lines
9.1 KiB
C

// SPDX-License-Identifier: GPL-2.0-only
/*
* amd76xrom.c
*
* Normal mappings of chips in physical memory
*/
#include <linux/module.h>
#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <asm/io.h>
#include <linux/mtd/mtd.h>
#include <linux/mtd/map.h>
#include <linux/mtd/cfi.h>
#include <linux/mtd/flashchip.h>
#include <linux/pci.h>
#include <linux/pci_ids.h>
#include <linux/list.h>
#define xstr(s) str(s)
#define str(s) #s
#define MOD_NAME xstr(KBUILD_BASENAME)
#define ADDRESS_NAME_LEN 18
#define ROM_PROBE_STEP_SIZE (64*1024) /* 64KiB */
struct amd76xrom_window {
void __iomem *virt;
unsigned long phys;
unsigned long size;
struct list_head maps;
struct resource rsrc;
struct pci_dev *pdev;
};
struct amd76xrom_map_info {
struct list_head list;
struct map_info map;
struct mtd_info *mtd;
struct resource rsrc;
char map_name[sizeof(MOD_NAME) + 2 + ADDRESS_NAME_LEN];
};
/* The 2 bits controlling the window size are often set to allow reading
* the BIOS, but too small to allow writing, since the lock registers are
* 4MiB lower in the address space than the data.
*
* This is intended to prevent flashing the bios, perhaps accidentally.
*
* This parameter allows the normal driver to over-ride the BIOS settings.
*
* The bits are 6 and 7. If both bits are set, it is a 5MiB window.
* If only the 7 Bit is set, it is a 4MiB window. Otherwise, a
* 64KiB window.
*
*/
static uint win_size_bits;
module_param(win_size_bits, uint, 0);
MODULE_PARM_DESC(win_size_bits, "ROM window size bits override for 0x43 byte, normally set by BIOS.");
static struct amd76xrom_window amd76xrom_window = {
.maps = LIST_HEAD_INIT(amd76xrom_window.maps),
};
static void amd76xrom_cleanup(struct amd76xrom_window *window)
{
struct amd76xrom_map_info *map, *scratch;
u8 byte;
if (window->pdev) {
/* Disable writes through the rom window */
pci_read_config_byte(window->pdev, 0x40, &byte);
pci_write_config_byte(window->pdev, 0x40, byte & ~1);
pci_dev_put(window->pdev);
}
/* Free all of the mtd devices */
list_for_each_entry_safe(map, scratch, &window->maps, list) {
if (map->rsrc.parent) {
release_resource(&map->rsrc);
}
mtd_device_unregister(map->mtd);
map_destroy(map->mtd);
list_del(&map->list);
kfree(map);
}
if (window->rsrc.parent)
release_resource(&window->rsrc);
if (window->virt) {
iounmap(window->virt);
window->virt = NULL;
window->phys = 0;
window->size = 0;
window->pdev = NULL;
}
}
static int amd76xrom_init_one(struct pci_dev *pdev,
const struct pci_device_id *ent)
{
static char *rom_probe_types[] = { "cfi_probe", "jedec_probe", NULL };
u8 byte;
struct amd76xrom_window *window = &amd76xrom_window;
struct amd76xrom_map_info *map = NULL;
unsigned long map_top;
/* Remember the pci dev I find the window in - already have a ref */
window->pdev = pdev;
/* Enable the selected rom window. This is often incorrectly
* set up by the BIOS, and the 4MiB offset for the lock registers
* requires the full 5MiB of window space.
*
* This 'write, then read' approach leaves the bits for
* other uses of the hardware info.
*/
pci_read_config_byte(pdev, 0x43, &byte);
pci_write_config_byte(pdev, 0x43, byte | win_size_bits );
/* Assume the rom window is properly setup, and find it's size */
pci_read_config_byte(pdev, 0x43, &byte);
if ((byte & ((1<<7)|(1<<6))) == ((1<<7)|(1<<6))) {
window->phys = 0xffb00000; /* 5MiB */
}
else if ((byte & (1<<7)) == (1<<7)) {
window->phys = 0xffc00000; /* 4MiB */
}
else {
window->phys = 0xffff0000; /* 64KiB */
}
window->size = 0xffffffffUL - window->phys + 1UL;
/*
* Try to reserve the window mem region. If this fails then
* it is likely due to a fragment of the window being
* "reserved" by the BIOS. In the case that the
* request_mem_region() fails then once the rom size is
* discovered we will try to reserve the unreserved fragment.
*/
window->rsrc.name = MOD_NAME;
window->rsrc.start = window->phys;
window->rsrc.end = window->phys + window->size - 1;
window->rsrc.flags = IORESOURCE_MEM | IORESOURCE_BUSY;
if (request_resource(&iomem_resource, &window->rsrc)) {
window->rsrc.parent = NULL;
printk(KERN_ERR MOD_NAME
" %s(): Unable to register resource %pR - kernel bug?\n",
__func__, &window->rsrc);
return -EBUSY;
}
/* Enable writes through the rom window */
pci_read_config_byte(pdev, 0x40, &byte);
pci_write_config_byte(pdev, 0x40, byte | 1);
/* FIXME handle registers 0x80 - 0x8C the bios region locks */
/* For write accesses caches are useless */
window->virt = ioremap(window->phys, window->size);
if (!window->virt) {
printk(KERN_ERR MOD_NAME ": ioremap(%08lx, %08lx) failed\n",
window->phys, window->size);
goto out;
}
/* Get the first address to look for an rom chip at */
map_top = window->phys;
#if 1
/* The probe sequence run over the firmware hub lock
* registers sets them to 0x7 (no access).
* Probe at most the last 4M of the address space.
*/
if (map_top < 0xffc00000) {
map_top = 0xffc00000;
}
#endif
/* Loop through and look for rom chips */
while((map_top - 1) < 0xffffffffUL) {
struct cfi_private *cfi;
unsigned long offset;
int i;
if (!map) {
map = kmalloc(sizeof(*map), GFP_KERNEL);
if (!map)
goto out;
}
memset(map, 0, sizeof(*map));
INIT_LIST_HEAD(&map->list);
map->map.name = map->map_name;
map->map.phys = map_top;
offset = map_top - window->phys;
map->map.virt = (void __iomem *)
(((unsigned long)(window->virt)) + offset);
map->map.size = 0xffffffffUL - map_top + 1UL;
/* Set the name of the map to the address I am trying */
sprintf(map->map_name, "%s @%08Lx",
MOD_NAME, (unsigned long long)map->map.phys);
/* There is no generic VPP support */
for(map->map.bankwidth = 32; map->map.bankwidth;
map->map.bankwidth >>= 1)
{
char **probe_type;
/* Skip bankwidths that are not supported */
if (!map_bankwidth_supported(map->map.bankwidth))
continue;
/* Setup the map methods */
simple_map_init(&map->map);
/* Try all of the probe methods */
probe_type = rom_probe_types;
for(; *probe_type; probe_type++) {
map->mtd = do_map_probe(*probe_type, &map->map);
if (map->mtd)
goto found;
}
}
map_top += ROM_PROBE_STEP_SIZE;
continue;
found:
/* Trim the size if we are larger than the map */
if (map->mtd->size > map->map.size) {
printk(KERN_WARNING MOD_NAME
" rom(%llu) larger than window(%lu). fixing...\n",
(unsigned long long)map->mtd->size, map->map.size);
map->mtd->size = map->map.size;
}
if (window->rsrc.parent) {
/*
* Registering the MTD device in iomem may not be possible
* if there is a BIOS "reserved" and BUSY range. If this
* fails then continue anyway.
*/
map->rsrc.name = map->map_name;
map->rsrc.start = map->map.phys;
map->rsrc.end = map->map.phys + map->mtd->size - 1;
map->rsrc.flags = IORESOURCE_MEM | IORESOURCE_BUSY;
if (request_resource(&window->rsrc, &map->rsrc)) {
printk(KERN_ERR MOD_NAME
": cannot reserve MTD resource\n");
map->rsrc.parent = NULL;
}
}
/* Make the whole region visible in the map */
map->map.virt = window->virt;
map->map.phys = window->phys;
cfi = map->map.fldrv_priv;
for(i = 0; i < cfi->numchips; i++) {
cfi->chips[i].start += offset;
}
/* Now that the mtd devices is complete claim and export it */
map->mtd->owner = THIS_MODULE;
if (mtd_device_register(map->mtd, NULL, 0)) {
map_destroy(map->mtd);
map->mtd = NULL;
goto out;
}
/* Calculate the new value of map_top */
map_top += map->mtd->size;
/* File away the map structure */
list_add(&map->list, &window->maps);
map = NULL;
}
out:
/* Free any left over map structures */
kfree(map);
/* See if I have any map structures */
if (list_empty(&window->maps)) {
amd76xrom_cleanup(window);
return -ENODEV;
}
return 0;
}
static void amd76xrom_remove_one(struct pci_dev *pdev)
{
struct amd76xrom_window *window = &amd76xrom_window;
amd76xrom_cleanup(window);
}
static const struct pci_device_id amd76xrom_pci_tbl[] = {
{ PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_VIPER_7410,
PCI_ANY_ID, PCI_ANY_ID, },
{ PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_VIPER_7440,
PCI_ANY_ID, PCI_ANY_ID, },
{ PCI_VENDOR_ID_AMD, 0x7468 }, /* amd8111 support */
{ 0, }
};
MODULE_DEVICE_TABLE(pci, amd76xrom_pci_tbl);
#if 0
static struct pci_driver amd76xrom_driver = {
.name = MOD_NAME,
.id_table = amd76xrom_pci_tbl,
.probe = amd76xrom_init_one,
.remove = amd76xrom_remove_one,
};
#endif
static int __init init_amd76xrom(void)
{
struct pci_dev *pdev;
const struct pci_device_id *id;
pdev = NULL;
for(id = amd76xrom_pci_tbl; id->vendor; id++) {
pdev = pci_get_device(id->vendor, id->device, NULL);
if (pdev) {
break;
}
}
if (pdev) {
return amd76xrom_init_one(pdev, &amd76xrom_pci_tbl[0]);
}
return -ENXIO;
#if 0
return pci_register_driver(&amd76xrom_driver);
#endif
}
static void __exit cleanup_amd76xrom(void)
{
amd76xrom_remove_one(amd76xrom_window.pdev);
}
module_init(init_amd76xrom);
module_exit(cleanup_amd76xrom);
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Eric Biederman <ebiederman@lnxi.com>");
MODULE_DESCRIPTION("MTD map driver for BIOS chips on the AMD76X southbridge");