[PATCH] docs: fix misinformation about overcommit_memory

[linux-2.6.git] / drivers / macintosh / macio_asic.c

/*
 * Bus & driver management routines for devices within
 * a MacIO ASIC. Interface to new driver model mostly
 * stolen from the PCI version.
 * 
 * TODO:
 * 
 *  - Don't probe below media bay by default, but instead provide
 *    some hooks for media bay to dynamically add/remove it's own
 *    sub-devices.
 */
 
#include <linux/config.h>
#include <linux/string.h>
#include <linux/kernel.h>
#include <linux/pci.h>
#include <linux/pci_ids.h>
#include <linux/init.h>
#include <linux/module.h>
#include <asm/machdep.h>
#include <asm/macio.h>
#include <asm/pmac_feature.h>
#include <asm/prom.h>
#include <asm/pci-bridge.h>

#undef DEBUG

#define MAX_NODE_NAME_SIZE (BUS_ID_SIZE - 12)

static struct macio_chip      *macio_on_hold;

static int macio_bus_match(struct device *dev, struct device_driver *drv) 
{
        struct macio_dev * macio_dev = to_macio_device(dev);
        struct macio_driver * macio_drv = to_macio_driver(drv);
        const struct of_device_id * matches = macio_drv->match_table;

        if (!matches) 
                return 0;

        return of_match_device(matches, &macio_dev->ofdev) != NULL;
}

struct macio_dev *macio_dev_get(struct macio_dev *dev)
{
        struct device *tmp;

        if (!dev)
                return NULL;
        tmp = get_device(&dev->ofdev.dev);
        if (tmp)
                return to_macio_device(tmp);
        else
                return NULL;
}

void macio_dev_put(struct macio_dev *dev)
{
        if (dev)
                put_device(&dev->ofdev.dev);
}


static int macio_device_probe(struct device *dev)
{
        int error = -ENODEV;
        struct macio_driver *drv;
        struct macio_dev *macio_dev;
        const struct of_device_id *match;

        drv = to_macio_driver(dev->driver);
        macio_dev = to_macio_device(dev);

        if (!drv->probe)
                return error;

        macio_dev_get(macio_dev);

        match = of_match_device(drv->match_table, &macio_dev->ofdev);
        if (match)
                error = drv->probe(macio_dev, match);
        if (error)
                macio_dev_put(macio_dev);

        return error;
}

static int macio_device_remove(struct device *dev)
{
        struct macio_dev * macio_dev = to_macio_device(dev);
        struct macio_driver * drv = to_macio_driver(dev->driver);

        if (dev->driver && drv->remove)
                drv->remove(macio_dev);
        macio_dev_put(macio_dev);

        return 0;
}

static void macio_device_shutdown(struct device *dev)
{
        struct macio_dev * macio_dev = to_macio_device(dev);
        struct macio_driver * drv = to_macio_driver(dev->driver);

        if (dev->driver && drv->shutdown)
                drv->shutdown(macio_dev);
}

static int macio_device_suspend(struct device *dev, pm_message_t state)
{
        struct macio_dev * macio_dev = to_macio_device(dev);
        struct macio_driver * drv = to_macio_driver(dev->driver);

        if (dev->driver && drv->suspend)
                return drv->suspend(macio_dev, state);
        return 0;
}

static int macio_device_resume(struct device * dev)
{
        struct macio_dev * macio_dev = to_macio_device(dev);
        struct macio_driver * drv = to_macio_driver(dev->driver);

        if (dev->driver && drv->resume)
                return drv->resume(macio_dev);
        return 0;
}

static int macio_hotplug (struct device *dev, char **envp, int num_envp,
                          char *buffer, int buffer_size)
{
        struct macio_dev * macio_dev;
        struct of_device * of;
        char *scratch, *compat;
        int i = 0;
        int length = 0;
        int cplen, seen = 0;

        if (!dev)
                return -ENODEV;

        macio_dev = to_macio_device(dev);
        if (!macio_dev)
                return -ENODEV;

        of = &macio_dev->ofdev;
        scratch = buffer;

        /* stuff we want to pass to /sbin/hotplug */
        envp[i++] = scratch;
        length += scnprintf (scratch, buffer_size - length, "OF_NAME=%s",
                             of->node->name);
        if ((buffer_size - length <= 0) || (i >= num_envp))
                return -ENOMEM;
        ++length;
        scratch += length;

        envp[i++] = scratch;
        length += scnprintf (scratch, buffer_size - length, "OF_TYPE=%s",
                             of->node->type);
        if ((buffer_size - length <= 0) || (i >= num_envp))
                return -ENOMEM;
        ++length;
        scratch += length;

        /* Since the compatible field can contain pretty much anything
         * it's not really legal to split it out with commas. We split it
         * up using a number of environment variables instead. */

        compat = (char *) get_property(of->node, "compatible", &cplen);
        while (compat && cplen > 0) {
                int l;
                envp[i++] = scratch;
                length += scnprintf (scratch, buffer_size - length,
                                     "OF_COMPATIBLE_%d=%s", seen, compat);
                if ((buffer_size - length <= 0) || (i >= num_envp))
                        return -ENOMEM;
                length++;
                scratch += length;
                l = strlen (compat) + 1;
                compat += l;
                cplen -= l;
                seen++;
        }

        envp[i++] = scratch;
        length += scnprintf (scratch, buffer_size - length,
                             "OF_COMPATIBLE_N=%d", seen);
        if ((buffer_size - length <= 0) || (i >= num_envp))
                return -ENOMEM;
        ++length;
        scratch += length;

        envp[i] = NULL;

        return 0;
}

extern struct device_attribute macio_dev_attrs[];

struct bus_type macio_bus_type = {
       .name    = "macio",
       .match   = macio_bus_match,
       .hotplug = macio_hotplug,
       .suspend = macio_device_suspend,
       .resume  = macio_device_resume,
       .dev_attrs = macio_dev_attrs,
};

static int __init macio_bus_driver_init(void)
{
        return bus_register(&macio_bus_type);
}

postcore_initcall(macio_bus_driver_init);


/**
 * macio_release_dev - free a macio device structure when all users of it are finished.
 * @dev: device that's been disconnected
 *
 * Will be called only by the device core when all users of this macio device are
 * done. This currently means never as we don't hot remove any macio device yet,
 * though that will happen with mediabay based devices in a later implementation.
 */
static void macio_release_dev(struct device *dev)
{
        struct macio_dev *mdev;

        mdev = to_macio_device(dev);
        kfree(mdev);
}

/**
 * macio_resource_quirks - tweak or skip some resources for a device
 * @np: pointer to the device node
 * @res: resulting resource
 * @index: index of resource in node
 *
 * If this routine returns non-null, then the resource is completely
 * skipped.
 */
static int macio_resource_quirks(struct device_node *np, struct resource *res, int index)
{
        if (res->flags & IORESOURCE_MEM) {
                /* Grand Central has too large resource 0 on some machines */
                if (index == 0 && !strcmp(np->name, "gc")) {
                        np->addrs[0].size = 0x20000;
                        res->end = res->start + 0x1ffff;
                }
                /* Airport has bogus resource 2 */
                if (index >= 2 && !strcmp(np->name, "radio"))
                        return 1;
                /* DBDMAs may have bogus sizes */
                if ((res->start & 0x0001f000) == 0x00008000) {
                        np->addrs[index].size = 0x100;
                        res->end = res->start + 0xff;
                }
                /* ESCC parent eats child resources. We could have added a level of hierarchy,
                 * but I don't really feel the need for it */
                if (!strcmp(np->name, "escc"))
                        return 1;
                /* ESCC has bogus resources >= 3 */
                if (index >= 3 && !(strcmp(np->name, "ch-a") && strcmp(np->name, "ch-b")))
                        return 1;
                /* Media bay has too many resources, keep only first one */
                if (index > 0 && !strcmp(np->name, "media-bay"))
                        return 1;
                /* Some older IDE resources have bogus sizes */
                if (!(strcmp(np->name, "IDE") && strcmp(np->name, "ATA") &&
                      strcmp(np->type, "ide") && strcmp(np->type, "ata"))) {
                        if (index == 0 && np->addrs[0].size > 0x1000) {
                                np->addrs[0].size = 0x1000;
                                res->end = res->start + 0xfff;
                        }
                        if (index == 1 && np->addrs[1].size > 0x100) {
                                np->addrs[1].size = 0x100;
                                res->end = res->start + 0xff;
                        }
                }
        }
        return 0;
}


/**
 * macio_add_one_device - Add one device from OF node to the device tree
 * @chip: pointer to the macio_chip holding the device
 * @np: pointer to the device node in the OF tree
 * @in_bay: set to 1 if device is part of a media-bay
 *
 * When media-bay is changed to hotswap drivers, this function will
 * be exposed to the bay driver some way...
 */
static struct macio_dev * macio_add_one_device(struct macio_chip *chip, struct device *parent,
                                               struct device_node *np, struct macio_dev *in_bay,
                                               struct resource *parent_res)
{
        struct macio_dev *dev;
        int i, j;
        u32 *reg;
        
        if (np == NULL)
                return NULL;

        dev = kmalloc(sizeof(*dev), GFP_KERNEL);
        if (!dev)
                return NULL;
        memset(dev, 0, sizeof(*dev));

        dev->bus = &chip->lbus;
        dev->media_bay = in_bay;
        dev->ofdev.node = np;
        dev->ofdev.dma_mask = 0xffffffffUL;
        dev->ofdev.dev.dma_mask = &dev->ofdev.dma_mask;
        dev->ofdev.dev.parent = parent;
        dev->ofdev.dev.bus = &macio_bus_type;
        dev->ofdev.dev.release = macio_release_dev;

#ifdef DEBUG
        printk("preparing mdev @%p, ofdev @%p, dev @%p, kobj @%p\n",
               dev, &dev->ofdev, &dev->ofdev.dev, &dev->ofdev.dev.kobj);
#endif

        /* MacIO itself has a different reg, we use it's PCI base */
        if (np == chip->of_node) {
                sprintf(dev->ofdev.dev.bus_id, "%1d.%08lx:%.*s", chip->lbus.index,
#ifdef CONFIG_PCI
                        pci_resource_start(chip->lbus.pdev, 0),
#else
                        0, /* NuBus may want to do something better here */
#endif
                        MAX_NODE_NAME_SIZE, np->name);
        } else {
                reg = (u32 *)get_property(np, "reg", NULL);
                sprintf(dev->ofdev.dev.bus_id, "%1d.%08x:%.*s", chip->lbus.index,
                        reg ? *reg : 0, MAX_NODE_NAME_SIZE, np->name);
        }

        /* For now, we use pre-parsed entries in the device-tree for
         * interrupt routing and addresses, but we should change that
         * to dynamically parsed entries and so get rid of most of the
         * clutter in struct device_node
         */
        for (i = j = 0; i < np->n_intrs; i++) {
                struct resource *res = &dev->interrupt[j];

                if (j >= MACIO_DEV_COUNT_IRQS)
                        break;
                res->start = np->intrs[i].line;
                res->flags = IORESOURCE_IO;
                if (np->intrs[j].sense)
                        res->flags |= IORESOURCE_IRQ_LOWLEVEL;
                else
                        res->flags |= IORESOURCE_IRQ_HIGHEDGE;
                res->name = dev->ofdev.dev.bus_id;
                if (macio_resource_quirks(np, res, i))
                        memset(res, 0, sizeof(struct resource));
                else
                        j++;
        }
        dev->n_interrupts = j;
        for (i = j = 0; i < np->n_addrs; i++) {
                struct resource *res = &dev->resource[j];
                
                if (j >= MACIO_DEV_COUNT_RESOURCES)
                        break;
                res->start = np->addrs[i].address;
                res->end = np->addrs[i].address + np->addrs[i].size - 1;
                res->flags = IORESOURCE_MEM;
                res->name = dev->ofdev.dev.bus_id;
                if (macio_resource_quirks(np, res, i))
                        memset(res, 0, sizeof(struct resource));
                else {
                        j++;
                        /* Currently, we consider failure as harmless, this may
                         * change in the future, once I've found all the device
                         * tree bugs in older machines & worked around them
                         */
                        if (insert_resource(parent_res, res))
                                printk(KERN_WARNING "Can't request resource %d for MacIO"
                                       " device %s\n", i, dev->ofdev.dev.bus_id);
                }
        }
        dev->n_resources = j;

        if (of_device_register(&dev->ofdev) != 0) {
                printk(KERN_DEBUG"macio: device registration error for %s!\n",
                       dev->ofdev.dev.bus_id);
                kfree(dev);
                return NULL;
        }

        return dev;
}

static int macio_skip_device(struct device_node *np)
{
        if (strncmp(np->name, "battery", 7) == 0)
                return 1;
        if (strncmp(np->name, "escc-legacy", 11) == 0)
                return 1;
        return 0;
}

/**
 * macio_pci_add_devices - Adds sub-devices of mac-io to the device tree
 * @chip: pointer to the macio_chip holding the devices
 * 
 * This function will do the job of extracting devices from the
 * Open Firmware device tree, build macio_dev structures and add
 * them to the Linux device tree.
 * 
 * For now, childs of media-bay are added now as well. This will
 * change rsn though.
 */
static void macio_pci_add_devices(struct macio_chip *chip)
{
        struct device_node *np, *pnode;
        struct macio_dev *rdev, *mdev, *mbdev = NULL, *sdev = NULL;
        struct device *parent = NULL;
        struct resource *root_res = &iomem_resource;
        
        /* Add a node for the macio bus itself */
#ifdef CONFIG_PCI
        if (chip->lbus.pdev) {
                parent = &chip->lbus.pdev->dev;
                root_res = &chip->lbus.pdev->resource[0];
        }
#endif
        pnode = of_node_get(chip->of_node);
        if (pnode == NULL)
                return;

        /* Add macio itself to hierarchy */
        rdev = macio_add_one_device(chip, parent, pnode, NULL, root_res);
        if (rdev == NULL)
                return;
        root_res = &rdev->resource[0];

        /* First scan 1st level */
        for (np = NULL; (np = of_get_next_child(pnode, np)) != NULL;) {
                if (!macio_skip_device(np)) {
                        of_node_get(np);
                        mdev = macio_add_one_device(chip, &rdev->ofdev.dev, np, NULL, root_res);
                        if (mdev == NULL)
                                of_node_put(np);
                        else if (strncmp(np->name, "media-bay", 9) == 0)
                                mbdev = mdev;
                        else if (strncmp(np->name, "escc", 4) == 0)
                                sdev = mdev;
                }
        }

        /* Add media bay devices if any */
        if (mbdev)
                for (np = NULL; (np = of_get_next_child(mbdev->ofdev.node, np)) != NULL;)
                        if (!macio_skip_device(np)) {
                                of_node_get(np);
                                if (macio_add_one_device(chip, &mbdev->ofdev.dev, np, mbdev,
                                                         root_res) == NULL)
                                        of_node_put(np);
                        }
        /* Add serial ports if any */
        if (sdev) {
                for (np = NULL; (np = of_get_next_child(sdev->ofdev.node, np)) != NULL;)
                        if (!macio_skip_device(np)) {
                                of_node_get(np);
                                if (macio_add_one_device(chip, &sdev->ofdev.dev, np, NULL,
                                                         root_res) == NULL)
                                        of_node_put(np);
                        }
        }
}


/**
 * macio_register_driver - Registers a new MacIO device driver
 * @drv: pointer to the driver definition structure
 */
int macio_register_driver(struct macio_driver *drv)
{
        int count = 0;

        /* initialize common driver fields */
        drv->driver.name = drv->name;
        drv->driver.bus = &macio_bus_type;
        drv->driver.probe = macio_device_probe;
        drv->driver.remove = macio_device_remove;
        drv->driver.shutdown = macio_device_shutdown;

        /* register with core */
        count = driver_register(&drv->driver);
        return count ? count : 1;
}

/**
 * macio_unregister_driver - Unregisters a new MacIO device driver
 * @drv: pointer to the driver definition structure
 */
void macio_unregister_driver(struct macio_driver *drv)
{
        driver_unregister(&drv->driver);
}

/**
 *      macio_request_resource - Request an MMIO resource
 *      @dev: pointer to the device holding the resource
 *      @resource_no: resource number to request
 *      @name: resource name
 *
 *      Mark  memory region number @resource_no associated with MacIO
 *      device @dev as being reserved by owner @name.  Do not access
 *      any address inside the memory regions unless this call returns
 *      successfully.
 *
 *      Returns 0 on success, or %EBUSY on error.  A warning
 *      message is also printed on failure.
 */
int macio_request_resource(struct macio_dev *dev, int resource_no, const char *name)
{
        if (macio_resource_len(dev, resource_no) == 0)
                return 0;
                
        if (!request_mem_region(macio_resource_start(dev, resource_no),
                                macio_resource_len(dev, resource_no),
                                name))
                goto err_out;
        
        return 0;

err_out:
        printk (KERN_WARNING "MacIO: Unable to reserve resource #%d:%lx@%lx"
                " for device %s\n",
                resource_no,
                macio_resource_len(dev, resource_no),
                macio_resource_start(dev, resource_no),
                dev->ofdev.dev.bus_id);
        return -EBUSY;
}

/**
 * macio_release_resource - Release an MMIO resource
 * @dev: pointer to the device holding the resource
 * @resource_no: resource number to release
 */
void macio_release_resource(struct macio_dev *dev, int resource_no)
{
        if (macio_resource_len(dev, resource_no) == 0)
                return;
        release_mem_region(macio_resource_start(dev, resource_no),
                           macio_resource_len(dev, resource_no));
}

/**
 *      macio_request_resources - Reserve all memory resources
 *      @dev: MacIO device whose resources are to be reserved
 *      @name: Name to be associated with resource.
 *
 *      Mark all memory regions associated with MacIO device @dev as
 *      being reserved by owner @name.  Do not access any address inside
 *      the memory regions unless this call returns successfully.
 *
 *      Returns 0 on success, or %EBUSY on error.  A warning
 *      message is also printed on failure.
 */
int macio_request_resources(struct macio_dev *dev, const char *name)
{
        int i;
        
        for (i = 0; i < dev->n_resources; i++)
                if (macio_request_resource(dev, i, name))
                        goto err_out;
        return 0;

err_out:
        while(--i >= 0)
                macio_release_resource(dev, i);
                
        return -EBUSY;
}

/**
 *      macio_release_resources - Release reserved memory resources
 *      @dev: MacIO device whose resources were previously reserved
 */

void macio_release_resources(struct macio_dev *dev)
{
        int i;
        
        for (i = 0; i < dev->n_resources; i++)
                macio_release_resource(dev, i);
}


#ifdef CONFIG_PCI

static int __devinit macio_pci_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
{
        struct device_node* np;
        struct macio_chip* chip;
        
        if (ent->vendor != PCI_VENDOR_ID_APPLE)
                return -ENODEV;

        /* Note regarding refcounting: We assume pci_device_to_OF_node() is ported
         * to new OF APIs and returns a node with refcount incremented. This isn't
         * the case today, but on the other hand ppc32 doesn't do refcounting. This
         * will have to be fixed when going to ppc64. --BenH.
         */
        np = pci_device_to_OF_node(pdev);
        if (np == NULL)
                return -ENODEV;

        /* This assumption is wrong, fix that here for now until I fix the arch */
        of_node_get(np);

        /* We also assume that pmac_feature will have done a get() on nodes stored
         * in the macio chips array
         */
        chip = macio_find(np, macio_unknown);
        of_node_put(np);
        if (chip == NULL)
                return -ENODEV;

        /* XXX Need locking ??? */
        if (chip->lbus.pdev == NULL) {
                chip->lbus.pdev = pdev;
                chip->lbus.chip = chip;
                pci_set_drvdata(pdev, &chip->lbus);
                pci_set_master(pdev);
        }

        printk(KERN_INFO "MacIO PCI driver attached to %s chipset\n",
                chip->name);

        /*
         * HACK ALERT: The WallStreet PowerBook and some OHare based machines
         * have 2 macio ASICs. I must probe the "main" one first or IDE ordering
         * will be incorrect. So I put on "hold" the second one since it seem to
         * appear first on PCI
         */
        if (chip->type == macio_gatwick || chip->type == macio_ohareII)
                if (macio_chips[0].lbus.pdev == NULL) {
                        macio_on_hold = chip;
                        return 0;
                }

        macio_pci_add_devices(chip);
        if (macio_on_hold && macio_chips[0].lbus.pdev != NULL) {
                macio_pci_add_devices(macio_on_hold);
                macio_on_hold = NULL;
        }

        return 0;
}

static void __devexit macio_pci_remove(struct pci_dev* pdev)
{
        panic("removing of macio-asic not supported !\n");
}

/*
 * MacIO is matched against any Apple ID, it's probe() function
 * will then decide wether it applies or not
 */
static const struct pci_device_id __devinitdata pci_ids [] = { {
        .vendor         = PCI_VENDOR_ID_APPLE,
        .device         = PCI_ANY_ID,
        .subvendor      = PCI_ANY_ID,
        .subdevice      = PCI_ANY_ID,

        }, { /* end: all zeroes */ }
};
MODULE_DEVICE_TABLE (pci, pci_ids);

/* pci driver glue; this is a "new style" PCI driver module */
static struct pci_driver macio_pci_driver = {
        .name           = (char *) "macio",
        .id_table       = pci_ids,

        .probe          = macio_pci_probe,
        .remove         = macio_pci_remove,
};

#endif /* CONFIG_PCI */

static int __init macio_module_init (void) 
{
#ifdef CONFIG_PCI
        int rc;

        rc = pci_register_driver(&macio_pci_driver);
        if (rc)
                return rc;
#endif /* CONFIG_PCI */
        return 0;
}

module_init(macio_module_init);

EXPORT_SYMBOL(macio_register_driver);
EXPORT_SYMBOL(macio_unregister_driver);
EXPORT_SYMBOL(macio_dev_get);
EXPORT_SYMBOL(macio_dev_put);
EXPORT_SYMBOL(macio_request_resource);
EXPORT_SYMBOL(macio_release_resource);
EXPORT_SYMBOL(macio_request_resources);
EXPORT_SYMBOL(macio_release_resources);