source: GPL/branches/uniaud32-next/lib32/devres.c

/*
 * drivers/base/devres.c - device resource management
 *
 * Copyright (c) 2006  SUSE Linux Products GmbH
 * Copyright (c) 2006  Tejun Heo <teheo@suse.de>
 *
 * This file is released under the GPLv2.
 */

#include <linux/device.h>
#include <linux/pci.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/gfp.h>
#include <linux/errno.h>
#include <asm/io.h>

struct devres_node {
        struct list_head                entry;
        dr_release_t                    release;
        const char                      *name;
        size_t                          size;
};

struct devres {
        struct devres_node              node;
        /* -- 3 pointers */
        u8              data[]; /* guarantee ull alignment */
};

struct devres_group {
        struct devres_node              node[2];
        void                            *id;
        int                             color;
        /* -- 8 pointers */
};

static void set_node_dbginfo(struct devres_node *node, const char *name,
                             size_t size)
{
        node->name = name;
        node->size = size;
}

#define devres_log(dev, node, op)       do {} while (0)

/*
 * Release functions for devres group.  These callbacks are used only
 * for identification.
 */
static void group_open_release(struct device *dev, void *res)
{
        /* noop */
}

static void group_close_release(struct device *dev, void *res)
{
        /* noop */
}

static struct devres_group * node_to_group(struct devres_node *node)
{
        if (node->release == &group_open_release)
                return container_of(node, struct devres_group, node[0]);
        if (node->release == &group_close_release)
                return container_of(node, struct devres_group, node[1]);
        return NULL;
}

static inline struct devres * alloc_dr(dr_release_t release,
                                                size_t size, gfp_t gfp, int nid)
{
        size_t tot_size = sizeof(struct devres) + size;
        struct devres *dr;

        dr = kmalloc_node_track_caller(tot_size, gfp, nid);

        memset(dr, 0, offsetof(struct devres, data));

        INIT_LIST_HEAD(&dr->node.entry);
        dr->node.release = release;
        return dr;
}

static void add_dr(struct device *dev, struct devres_node *node)
{
        devres_log(dev, node, "ADD");
        BUG_ON(!list_empty(&node->entry));
        list_add_tail(&node->entry, &dev->devres_head);
}

/**
 * devres_add - Register device resource
 * @dev: Device to add resource to
 * @res: Resource to register
 *
 * Register devres @res to @dev.  @res should have been allocated
 * using devres_alloc().  On driver detach, the associated release
 * function will be invoked and devres will be freed automatically.
 */
void devres_add(struct device *dev, void *res)
{
        struct devres *dr = container_of(res, struct devres, data);
        unsigned long flags;

        spin_lock_irqsave(&dev->devres_lock, flags);
        add_dr(dev, &dr->node);
        spin_unlock_irqrestore(&dev->devres_lock, flags);
}

/**
 * __devres_alloc_node - Allocate device resource data
 * @release: Release function devres will be associated with
 * @size: Allocation size
 * @gfp: Allocation flags
 * @nid: NUMA node
 * @name: Name of the resource
 *
 * Allocate devres of @size bytes.  The allocated area is zeroed, then
 * associated with @release.  The returned pointer can be passed to
 * other devres_*() functions.
 *
 * RETURNS:
 * Pointer to allocated devres on success, NULL on failure.
 */
void *__devres_alloc_node(dr_release_t release, size_t size, gfp_t gfp, int nid,
                          const char *name)
{
        struct devres *dr;

        dr = alloc_dr(release, size, gfp | __GFP_ZERO, nid);
        if (unlikely(!dr))
                return NULL;
        set_node_dbginfo(&dr->node, name, size);
        return dr->data;
}

/**
 * devres_free - Free device resource data
 * @res: Pointer to devres data to free
 *
 * Free devres created with devres_alloc().
 */
void devres_free(void *res)
{
        if (res) {
                struct devres *dr = container_of(res, struct devres, data);

                BUG_ON(!list_empty(&dr->node.entry));
                kfree(dr);
        }
}

static int remove_nodes(struct device *dev,
                        struct list_head *first, struct list_head *end,
                        struct list_head *todo)
{
        int cnt = 0, nr_groups = 0;
        struct list_head *cur;

        /* First pass - move normal devres entries to @todo and clear
         * devres_group colors.
         */
        cur = first;
        while (cur != end) {
                struct devres_node *node;
                struct devres_group *grp;

                node = list_entry(cur, struct devres_node, entry);
                cur = cur->next;

                grp = node_to_group(node);
                if (grp) {
                        /* clear color of group markers in the first pass */
                        grp->color = 0;
                        nr_groups++;
                } else {
                        /* regular devres entry */
                        if (&node->entry == first)
                                first = first->next;
                        list_move_tail(&node->entry, todo);
                        cnt++;
                }
        }

        if (!nr_groups)
                return cnt;

        /* Second pass - Scan groups and color them.  A group gets
         * color value of two iff the group is wholly contained in
         * [cur, end).  That is, for a closed group, both opening and
         * closing markers should be in the range, while just the
         * opening marker is enough for an open group.
         */
        cur = first;
        while (cur != end) {
                struct devres_node *node;
                struct devres_group *grp;

                node = list_entry(cur, struct devres_node, entry);
                cur = cur->next;

                grp = node_to_group(node);
                BUG_ON(!grp || list_empty(&grp->node[0].entry));

                grp->color++;
                if (list_empty(&grp->node[1].entry))
                        grp->color++;

                BUG_ON(grp->color <= 0 || grp->color > 2);
                if (grp->color == 2) {
                        /* No need to update cur or end.  The removed
                         * nodes are always before both.
                         */
                        list_move_tail(&grp->node[0].entry, todo);
                        list_del_init(&grp->node[1].entry);
                }
        }

        return cnt;
}

static int release_nodes(struct device *dev, struct list_head *first,
                         struct list_head *end, unsigned long flags)
{
//      LIST_HEAD(todo);
        struct list_head todo;

        int cnt;
        struct devres *dr, *tmp;

        cnt = remove_nodes(dev, first, end, &todo);

        spin_unlock_irqrestore(&dev->devres_lock, flags);

        /* Release.  Note that both devres and devres_group are
         * handled as devres in the following loop.  This is safe.
         */
        list_for_each_entry_safe_reverse(dr, tmp, &todo, node.entry, struct devres) {
                devres_log(dev, &dr->node, "REL");
                dr->node.release(dev, dr->data);
                kfree(dr);
        }

        return cnt;
}

/**
 * devres_release_all - Release all managed resources
 * @dev: Device to release resources for
 *
 * Release all resources associated with @dev.  This function is
 * called on driver detach.
 */
int devres_release_all(struct device *dev)
{
        unsigned long flags;

        /* Looks like an uninitialized device structure */
        if (WARN_ON(dev->devres_head.next == NULL))
                return -ENODEV;
        spin_lock_irqsave(&dev->devres_lock, flags);
        return release_nodes(dev, dev->devres_head.next, &dev->devres_head,
                             flags);
}

static struct devres *find_dr(struct device *dev, dr_release_t release,
                              dr_match_t match, void *match_data)
{
        struct devres_node *node;

        list_for_each_entry_reverse(node, &dev->devres_head, entry, struct devres_node) {
                struct devres *dr = container_of(node, struct devres, node);

                if (node->release != release)
                        continue;
                if (match && !match(dev, dr->data, match_data))
                        continue;
                return dr;
        }

        return NULL;
}

/**
 * devres_find - Find device resource
 * @dev: Device to lookup resource from
 * @release: Look for resources associated with this release function
 * @match: Match function (optional)
 * @match_data: Data for the match function
 *
 * Find the latest devres of @dev which is associated with @release
 * and for which @match returns 1.  If @match is NULL, it's considered
 * to match all.
 *
 * RETURNS:
 * Pointer to found devres, NULL if not found.
 */
void * devres_find(struct device *dev, dr_release_t release,
                   dr_match_t match, void *match_data)
{
        struct devres *dr;
        unsigned long flags;

        spin_lock_irqsave(&dev->devres_lock, flags);
        dr = find_dr(dev, release, match, match_data);
        spin_unlock_irqrestore(&dev->devres_lock, flags);

        if (dr)
                return dr->data;
        return NULL;
}

/**
 * devres_get - Find devres, if non-existent, add one atomically
 * @dev: Device to lookup or add devres for
 * @new_res: Pointer to new initialized devres to add if not found
 * @match: Match function (optional)
 * @match_data: Data for the match function
 *
 * Find the latest devres of @dev which has the same release function
 * as @new_res and for which @match return 1.  If found, @new_res is
 * freed; otherwise, @new_res is added atomically.
 *
 * RETURNS:
 * Pointer to found or added devres.
 */
void * devres_get(struct device *dev, void *new_res,
                  dr_match_t match, void *match_data)
{
        struct devres *new_dr = container_of(new_res, struct devres, data);
        struct devres *dr;
        unsigned long flags;

        spin_lock_irqsave(&dev->devres_lock, flags);
        dr = find_dr(dev, new_dr->node.release, match, match_data);
        if (!dr) {
                add_dr(dev, &new_dr->node);
                dr = new_dr;
                new_res = NULL;
        }
        spin_unlock_irqrestore(&dev->devres_lock, flags);
        devres_free(new_res);

        return dr->data;
}
EXPORT_SYMBOL_GPL(devres_get);

/*
 * Custom devres actions allow inserting a simple function call
 * into the teadown sequence.
 */

struct action_devres {
        void *data;
        void (*action)(void *);
};

static void devm_action_release(struct device *dev, void *res)
{
        struct action_devres *devres = res;

        devres->action(devres->data);
}

/**
 * devm_add_action() - add a custom action to list of managed resources
 * @dev: Device that owns the action
 * @action: Function that should be called
 * @data: Pointer to data passed to @action implementation
 *
 * This adds a custom action to the list of managed resources so that
 * it gets executed as part of standard resource unwinding.
 */
int devm_add_action(struct device *dev, void (*action)(void *), void *data)
{
        struct action_devres *devres;

        devres = devres_alloc(devm_action_release,
                              sizeof(struct action_devres), GFP_KERNEL);
        if (!devres)
                return -ENOMEM;

        devres->data = data;
        devres->action = action;

        devres_add(dev, devres);

        return 0;
}

/**
 * devm_remove_action() - removes previously added custom action
 * @dev: Device that owns the action
 * @action: Function implementing the action
 * @data: Pointer to data passed to @action implementation
 *
 * Removes instance of @action previously added by devm_add_action().
 * Both action and data should match one of the existing entries.
 */
void devm_remove_action(struct device *dev, void (*action)(void *), void *data)
{
}

/*
 * Managed kmalloc/kfree
 */
static void devm_kmalloc_release(struct device *dev, void *res)
{
        /* noop */
}

/**
 * devm_kmalloc - Resource-managed kmalloc
 * @dev: Device to allocate memory for
 * @size: Allocation size
 * @gfp: Allocation gfp flags
 *
 * Managed kmalloc.  Memory allocated with this function is
 * automatically freed on driver detach.  Like all other devres
 * resources, guaranteed alignment is unsigned long long.
 *
 * RETURNS:
 * Pointer to allocated memory on success, NULL on failure.
 */
void *devm_kmalloc(struct device *dev, size_t size, gfp_t gfp)
{
        struct devres *dr;

        if (unlikely(!size))
                return ZERO_SIZE_PTR;

        /* use raw alloc_dr for kmalloc caller tracing */
        dr = alloc_dr(devm_kmalloc_release, size, gfp, dev_to_node(dev));
        if (unlikely(!dr))
                return NULL;

        /*
         * This is named devm_kzalloc_release for historical reasons
         * The initial implementation did not support kmalloc, only kzalloc
         */
        set_node_dbginfo(&dr->node, "devm_kzalloc_release", size);
        devres_add(dev, dr->data);
        return dr->data;
}
EXPORT_SYMBOL_GPL(devm_kmalloc);

enum devm_ioremap_type {
        DEVM_IOREMAP = 0,
        DEVM_IOREMAP_UC,
        DEVM_IOREMAP_WC,
        DEVM_IOREMAP_NP,
};

void devm_ioremap_release(struct device *dev, void *res)
{
        iounmap(*(void __iomem **)res);
}

static void *__devm_ioremap(struct device *dev, resource_size_t offset,
                                    resource_size_t size,
                                    enum devm_ioremap_type type)
{
        void __iomem **ptr, *addr = NULL;

        ptr = devres_alloc(devm_ioremap_release, sizeof(*ptr), GFP_KERNEL);
        if (!ptr)
                return NULL;

        switch (type) {
        case DEVM_IOREMAP:
                addr = ioremap(offset, size);
                break;
#if 0
        case DEVM_IOREMAP_UC:
                addr = ioremap_uc(offset, size);
                break;
        case DEVM_IOREMAP_WC:
                addr = ioremap_wc(offset, size);
                break;
        case DEVM_IOREMAP_NP:
                addr = ioremap_np(offset, size);
                break;
#endif
        }

        if (addr) {
                *ptr = addr;
                devres_add(dev, ptr);
        } else
                devres_free(ptr);

        return addr;
}

/**
 * devm_ioremap - Managed ioremap()
 * @dev: Generic device to remap IO address for
 * @offset: Resource address to map
 * @size: Size of map
 *
 * Managed ioremap().  Map is automatically unmapped on driver detach.
 */
void __iomem *devm_ioremap(struct device *dev, resource_size_t offset,
                           resource_size_t size)
{
        return __devm_ioremap(dev, offset, size, DEVM_IOREMAP);
}
EXPORT_SYMBOL(devm_ioremap);

/**
 * devm_kvasprintf - Allocate resource managed space and format a string
 *                   into that.
 * @dev: Device to allocate memory for
 * @gfp: the GFP mask used in the devm_kmalloc() call when
 *       allocating memory
 * @fmt: The printf()-style format string
 * @ap: Arguments for the format string
 * RETURNS:
 * Pointer to allocated string on success, NULL on failure.
 */
char *devm_kvasprintf(struct device *dev, gfp_t gfp, const char *fmt,
                      va_list ap)
{
        unsigned int len;
        char *p;
        va_list aq;

        va_copy(aq, ap);
        len = vsnprintf(NULL, 0, fmt, aq);
        va_end(aq);

        p = devm_kmalloc(dev, len+1, gfp);
        if (!p)
                return NULL;

        vsnprintf(p, len+1, fmt, ap);

        return p;
}
EXPORT_SYMBOL(devm_kvasprintf);
/**
 * devm_kasprintf - Allocate resource managed space and format a string
 *                  into that.
 * @dev: Device to allocate memory for
 * @gfp: the GFP mask used in the devm_kmalloc() call when
 *       allocating memory
 * @fmt: The printf()-style format string
 * @...: Arguments for the format string
 * RETURNS:
 * Pointer to allocated string on success, NULL on failure.
 */
char *devm_kasprintf(struct device *dev, gfp_t gfp, const char *fmt, ...)
{
        va_list ap;
        char *p;

        va_start(ap, fmt);
        p = devm_kvasprintf(dev, gfp, fmt, ap);
        va_end(ap);

        return p;
}
EXPORT_SYMBOL_GPL(devm_kasprintf);

/*
 * PCI iomap devres
 */
#define PCIM_IOMAP_MAX  PCI_STD_NUM_BARS

struct pcim_iomap_devres {
        void __iomem *table[PCIM_IOMAP_MAX];
};

static void pcim_iomap_release(struct device *gendev, void *res)
{
        struct pci_dev *dev = to_pci_dev(gendev);
        struct pcim_iomap_devres *this = res;
        int i;

        for (i = 0; i < PCIM_IOMAP_MAX; i++)
                if (this->table[i])
                        pci_iounmap(dev, this->table[i]);
}

/**
 * pcim_iomap_table - access iomap allocation table
 * @pdev: PCI device to access iomap table for
 *
 * Access iomap allocation table for @dev.  If iomap table doesn't
 * exist and @pdev is managed, it will be allocated.  All iomaps
 * recorded in the iomap table are automatically unmapped on driver
 * detach.
 *
 * This function might sleep when the table is first allocated but can
 * be safely called without context and guaranteed to succeed once
 * allocated.
 */
void __iomem * const *pcim_iomap_table(struct pci_dev *pdev)
{
        struct pcim_iomap_devres *dr, *new_dr;

        dr = devres_find(&pdev->dev, pcim_iomap_release, NULL, NULL);
        if (dr)
                return dr->table;

        new_dr = devres_alloc(pcim_iomap_release, sizeof(*new_dr), GFP_KERNEL);
        if (!new_dr)
                return NULL;
        dr = devres_get(&pdev->dev, new_dr, NULL, NULL);
        return dr->table;
}
EXPORT_SYMBOL(pcim_iomap_table);

/**
 * pcim_iomap - Managed pcim_iomap()
 * @pdev: PCI device to iomap for
 * @bar: BAR to iomap
 * @maxlen: Maximum length of iomap
 *
 * Managed pci_iomap().  Map is automatically unmapped on driver
 * detach.
 */
void __iomem *pcim_iomap(struct pci_dev *pdev, int bar, unsigned long maxlen)
{
        void __iomem **tbl;

        BUG_ON(bar >= PCIM_IOMAP_MAX);

        tbl = (void __iomem **)pcim_iomap_table(pdev);
        if (!tbl || tbl[bar])   /* duplicate mappings not allowed */
                return NULL;

        tbl[bar] = pci_iomap(pdev, bar, maxlen);
        return tbl[bar];
}
EXPORT_SYMBOL(pcim_iomap);

/**
 * pcim_iounmap - Managed pci_iounmap()
 * @pdev: PCI device to iounmap for
 * @addr: Address to unmap
 *
 * Managed pci_iounmap().  @addr must have been mapped using pcim_iomap().
 */
void pcim_iounmap(struct pci_dev *pdev, void __iomem *addr)
{
        void __iomem **tbl;
        int i;

        pci_iounmap(pdev, addr);

        tbl = (void __iomem **)pcim_iomap_table(pdev);
        BUG_ON(!tbl);

        for (i = 0; i < PCIM_IOMAP_MAX; i++)
                if (tbl[i] == addr) {
                        tbl[i] = NULL;
                        return;
                }
        WARN_ON(1);
}
EXPORT_SYMBOL(pcim_iounmap);

/**
 * pcim_iomap_regions - Request and iomap PCI BARs
 * @pdev: PCI device to map IO resources for
 * @mask: Mask of BARs to request and iomap
 * @name: Name used when requesting regions
 *
 * Request and iomap regions specified by @mask.
 */
int pcim_iomap_regions(struct pci_dev *pdev, int mask, const char *name)
{
        void __iomem * const *iomap;
        int i, rc;

        iomap = pcim_iomap_table(pdev);
        if (!iomap)
                return -ENOMEM;

        for (i = 0; i < DEVICE_COUNT_RESOURCE; i++) {
                unsigned long len;

                if (!(mask & (1 << i)))
                        continue;

                rc = -EINVAL;
                len = pci_resource_len(pdev, i);
                if (!len)
                        goto err_inval;

                rc = pci_request_region(pdev, i, name);
                if (rc)
                        goto err_inval;

                rc = -ENOMEM;
                if (!pcim_iomap(pdev, i, 0))
                        goto err_region;
        }

        return 0;

 err_region:
        pci_release_region(pdev, i);
 err_inval:
        while (--i >= 0) {
                if (!(mask & (1 << i)))
                        continue;
                pcim_iounmap(pdev, iomap[i]);
                pci_release_region(pdev, i);
        }

        return rc;
}
EXPORT_SYMBOL(pcim_iomap_regions);