ichxrom.c

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/*
 * ichxrom.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 */

#define BIOS_CNTL   0x4e
#define FWH_DEC_EN1 0xE3
#define FWH_DEC_EN2 0xF0
#define FWH_SEL1    0xE8
#define FWH_SEL2    0xEE

struct ichxrom_window {
    void __iomem* virt;
    unsigned long phys;
    unsigned long size;
    struct list_head maps;
    struct resource rsrc;
    struct pci_dev *pdev;
};

struct ichxrom_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];
};

static struct ichxrom_window ichxrom_window = {
    .maps = LIST_HEAD_INIT(ichxrom_window.maps),
};

static void ichxrom_cleanup(struct ichxrom_window *window)
{
    struct ichxrom_map_info *map, *scratch;
    u16 word;

    /* Disable writes through the rom window */
    pci_read_config_word(window->pdev, BIOS_CNTL, &word);
    pci_write_config_word(window->pdev, BIOS_CNTL, word & ~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 __devinit ichxrom_init_one (struct pci_dev *pdev,
    const struct pci_device_id *ent)
{
    static char *rom_probe_types[] = { "cfi_probe", "jedec_probe", NULL };
    struct ichxrom_window *window = &ichxrom_window;
    struct ichxrom_map_info *map = NULL;
    unsigned long map_top;
    u8 byte;
    u16 word;

    /* For now I just handle the ichx and I assume there
     * are not a lot of resources up at the top of the address
     * space.  It is possible to handle other devices in the
     * top 16MB but it is very painful.  Also since
     * you can only really attach a FWH to an ICHX there
     * a number of simplifications you can make.
     *
     * Also you can page firmware hubs if an 8MB window isn't enough
     * but don't currently handle that case either.
     */
    window->pdev = pdev;

    /* Find a region continuous to the end of the ROM window  */
    window->phys = 0;
    pci_read_config_byte(pdev, FWH_DEC_EN1, &byte);
    if (byte == 0xff) {
        window->phys = 0xffc00000;
        pci_read_config_byte(pdev, FWH_DEC_EN2, &byte);
        if ((byte & 0x0f) == 0x0f) {
            window->phys = 0xff400000;
        }
        else if ((byte & 0x0e) == 0x0e) {
            window->phys = 0xff500000;
        }
        else if ((byte & 0x0c) == 0x0c) {
            window->phys = 0xff600000;
        }
        else if ((byte & 0x08) == 0x08) {
            window->phys = 0xff700000;
        }
    }
    else if ((byte & 0xfe) == 0xfe) {
        window->phys = 0xffc80000;
    }
    else if ((byte & 0xfc) == 0xfc) {
        window->phys = 0xffd00000;
    }
    else if ((byte & 0xf8) == 0xf8) {
        window->phys = 0xffd80000;
    }
    else if ((byte & 0xf0) == 0xf0) {
        window->phys = 0xffe00000;
    }
    else if ((byte & 0xe0) == 0xe0) {
        window->phys = 0xffe80000;
    }
    else if ((byte & 0xc0) == 0xc0) {
        window->phys = 0xfff00000;
    }
    else if ((byte & 0x80) == 0x80) {
        window->phys = 0xfff80000;
    }

    if (window->phys == 0) {
        printk(KERN_ERR MOD_NAME ": Rom window is closed\n");
        goto out;
    }
    window->phys -= 0x400000UL;
    window->size = (0xffffffffUL - window->phys) + 1UL;

    /* Enable writes through the rom window */
    pci_read_config_word(pdev, BIOS_CNTL, &word);
    if (!(word & 1)  && (word & (1<<1))) {
        /* The BIOS will generate an error if I enable
         * this device, so don't even try.
         */
        printk(KERN_ERR MOD_NAME ": firmware access control, I can't enable writes\n");
        goto out;
    }
    pci_write_config_word(pdev, BIOS_CNTL, word | 1);

    /*
     * Try to reserve the window mem region.  If this fails then
     * it is likely due to the window being "reseved" by the BIOS.
     */
    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_DEBUG MOD_NAME ": "
               "%s(): Unable to register resource %pR - kernel bug?\n",
               __func__, &window->rsrc);
    }

    /* Map the firmware hub into my address space. */
    window->virt = ioremap_nocache(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 ((window->phys & 0x3fffff) != 0) {
        map_top = window->phys + 0x400000;
    }
#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) {
            printk(KERN_ERR MOD_NAME ": kmalloc failed");
            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);

        /* Firmware hubs only use vpp when being programmed
         * in a factory setting.  So in-place programming
         * needs to use a different method.
         */
        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)) {
        ichxrom_cleanup(window);
        return -ENODEV;
    }
    return 0;
}


static void __devexit ichxrom_remove_one (struct pci_dev *pdev)
{
    struct ichxrom_window *window = &ichxrom_window;
    ichxrom_cleanup(window);
}

static struct pci_device_id ichxrom_pci_tbl[] __devinitdata = {
    { PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_82801BA_0,
      PCI_ANY_ID, PCI_ANY_ID, },
    { PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_82801CA_0,
      PCI_ANY_ID, PCI_ANY_ID, },
    { PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_82801DB_0,
      PCI_ANY_ID, PCI_ANY_ID, },
    { PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_82801EB_0,
      PCI_ANY_ID, PCI_ANY_ID, },
    { PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_ESB_1,
      PCI_ANY_ID, PCI_ANY_ID, },
    { 0, },
};

#if 0
MODULE_DEVICE_TABLE(pci, ichxrom_pci_tbl);

static struct pci_driver ichxrom_driver = {
    .name =     MOD_NAME,
    .id_table = ichxrom_pci_tbl,
    .probe =    ichxrom_init_one,
    .remove =   ichxrom_remove_one,
};
#endif

static int __init init_ichxrom(void)
{
    struct pci_dev *pdev;
    struct pci_device_id *id;

    pdev = NULL;
    for (id = ichxrom_pci_tbl; id->vendor; id++) {
        pdev = pci_get_device(id->vendor, id->device, NULL);
        if (pdev) {
            break;
        }
    }
    if (pdev) {
        return ichxrom_init_one(pdev, &ichxrom_pci_tbl[0]);
    }
    return -ENXIO;
#if 0
    return pci_register_driver(&ichxrom_driver);
#endif
}

static void __exit cleanup_ichxrom(void)
{
    ichxrom_remove_one(ichxrom_window.pdev);
}

module_init(init_ichxrom);
module_exit(cleanup_ichxrom);

MODULE_LICENSE("GPL");
MODULE_AUTHOR("Eric Biederman <[email protected]>");
MODULE_DESCRIPTION("MTD map driver for BIOS chips on the ICHX southbridge");