cpuset: fix possible deadlock in async_rebuild_sched_domains

[linux-2.6/linux-acpi-2.6/ibm-acpi-2.6.git] / drivers / ieee1394 / highlevel.c

/*
 * IEEE 1394 for Linux
 *
 * Copyright (C) 1999 Andreas E. Bombe
 *
 * This code is licensed under the GPL.  See the file COPYING in the root
 * directory of the kernel sources for details.
 *
 *
 * Contributions:
 *
 * Christian Toegel <christian.toegel@gmx.at>
 *        unregister address space
 *
 * Manfred Weihs <weihs@ict.tuwien.ac.at>
 *        unregister address space
 *
 */

#include <linux/slab.h>
#include <linux/list.h>
#include <linux/bitops.h>

#include "ieee1394.h"
#include "ieee1394_types.h"
#include "hosts.h"
#include "ieee1394_core.h"
#include "highlevel.h"
#include "nodemgr.h"


struct hl_host_info {
        struct list_head list;
        struct hpsb_host *host;
        size_t size;
        unsigned long key;
        void *data;
};


static LIST_HEAD(hl_drivers);
static DECLARE_RWSEM(hl_drivers_sem);

static LIST_HEAD(hl_irqs);
static DEFINE_RWLOCK(hl_irqs_lock);

static DEFINE_RWLOCK(addr_space_lock);


static struct hl_host_info *hl_get_hostinfo(struct hpsb_highlevel *hl,
                                            struct hpsb_host *host)
{
        struct hl_host_info *hi = NULL;

        if (!hl || !host)
                return NULL;

        read_lock(&hl->host_info_lock);
        list_for_each_entry(hi, &hl->host_info_list, list) {
                if (hi->host == host) {
                        read_unlock(&hl->host_info_lock);
                        return hi;
                }
        }
        read_unlock(&hl->host_info_lock);
        return NULL;
}

/**
 * hpsb_get_hostinfo - retrieve a hostinfo pointer bound to this driver/host
 *
 * Returns a per @host and @hl driver data structure that was previously stored
 * by hpsb_create_hostinfo.
 */
void *hpsb_get_hostinfo(struct hpsb_highlevel *hl, struct hpsb_host *host)
{
        struct hl_host_info *hi = hl_get_hostinfo(hl, host);

        return hi ? hi->data : NULL;
}

/**
 * hpsb_create_hostinfo - allocate a hostinfo pointer bound to this driver/host
 *
 * Allocate a hostinfo pointer backed by memory with @data_size and bind it to
 * to this @hl driver and @host.  If @data_size is zero, then the return here is
 * only valid for error checking.
 */
void *hpsb_create_hostinfo(struct hpsb_highlevel *hl, struct hpsb_host *host,
                           size_t data_size)
{
        struct hl_host_info *hi;
        void *data;
        unsigned long flags;

        hi = hl_get_hostinfo(hl, host);
        if (hi) {
                HPSB_ERR("%s called hpsb_create_hostinfo when hostinfo already"
                         " exists", hl->name);
                return NULL;
        }

        hi = kzalloc(sizeof(*hi) + data_size, GFP_ATOMIC);
        if (!hi)
                return NULL;

        if (data_size) {
                data = hi->data = hi + 1;
                hi->size = data_size;
        } else
                data = hi;

        hi->host = host;

        write_lock_irqsave(&hl->host_info_lock, flags);
        list_add_tail(&hi->list, &hl->host_info_list);
        write_unlock_irqrestore(&hl->host_info_lock, flags);

        return data;
}

/**
 * hpsb_set_hostinfo - set the hostinfo pointer to something useful
 *
 * Usually follows a call to hpsb_create_hostinfo, where the size is 0.
 */
int hpsb_set_hostinfo(struct hpsb_highlevel *hl, struct hpsb_host *host,
                      void *data)
{
        struct hl_host_info *hi;

        hi = hl_get_hostinfo(hl, host);
        if (hi) {
                if (!hi->size && !hi->data) {
                        hi->data = data;
                        return 0;
                } else
                        HPSB_ERR("%s called hpsb_set_hostinfo when hostinfo "
                                 "already has data", hl->name);
        } else
                HPSB_ERR("%s called hpsb_set_hostinfo when no hostinfo exists",
                         hl->name);
        return -EINVAL;
}

/**
 * hpsb_destroy_hostinfo - free and remove a hostinfo pointer
 *
 * Free and remove the hostinfo pointer bound to this @hl driver and @host.
 */
void hpsb_destroy_hostinfo(struct hpsb_highlevel *hl, struct hpsb_host *host)
{
        struct hl_host_info *hi;

        hi = hl_get_hostinfo(hl, host);
        if (hi) {
                unsigned long flags;
                write_lock_irqsave(&hl->host_info_lock, flags);
                list_del(&hi->list);
                write_unlock_irqrestore(&hl->host_info_lock, flags);
                kfree(hi);
        }
        return;
}

/**
 * hpsb_set_hostinfo_key - set an alternate lookup key for an hostinfo
 *
 * Sets an alternate lookup key for the hostinfo bound to this @hl driver and
 * @host.
 */
void hpsb_set_hostinfo_key(struct hpsb_highlevel *hl, struct hpsb_host *host,
                           unsigned long key)
{
        struct hl_host_info *hi;

        hi = hl_get_hostinfo(hl, host);
        if (hi)
                hi->key = key;
        return;
}

/**
 * hpsb_get_hostinfo_bykey - retrieve a hostinfo pointer by its alternate key
 */
void *hpsb_get_hostinfo_bykey(struct hpsb_highlevel *hl, unsigned long key)
{
        struct hl_host_info *hi;
        void *data = NULL;

        if (!hl)
                return NULL;

        read_lock(&hl->host_info_lock);
        list_for_each_entry(hi, &hl->host_info_list, list) {
                if (hi->key == key) {
                        data = hi->data;
                        break;
                }
        }
        read_unlock(&hl->host_info_lock);
        return data;
}

static int highlevel_for_each_host_reg(struct hpsb_host *host, void *__data)
{
        struct hpsb_highlevel *hl = __data;

        hl->add_host(host);

        if (host->update_config_rom && hpsb_update_config_rom_image(host) < 0)
                HPSB_ERR("Failed to generate Configuration ROM image for host "
                         "%s-%d", hl->name, host->id);
        return 0;
}

/**
 * hpsb_register_highlevel - register highlevel driver
 *
 * The name pointer in @hl has to stay valid at all times because the string is
 * not copied.
 */
void hpsb_register_highlevel(struct hpsb_highlevel *hl)
{
        unsigned long flags;

        hpsb_init_highlevel(hl);
        INIT_LIST_HEAD(&hl->addr_list);

        down_write(&hl_drivers_sem);
        list_add_tail(&hl->hl_list, &hl_drivers);
        up_write(&hl_drivers_sem);

        write_lock_irqsave(&hl_irqs_lock, flags);
        list_add_tail(&hl->irq_list, &hl_irqs);
        write_unlock_irqrestore(&hl_irqs_lock, flags);

        if (hl->add_host)
                nodemgr_for_each_host(hl, highlevel_for_each_host_reg);
        return;
}

static void __delete_addr(struct hpsb_address_serve *as)
{
        list_del(&as->host_list);
        list_del(&as->hl_list);
        kfree(as);
}

static void __unregister_host(struct hpsb_highlevel *hl, struct hpsb_host *host,
                              int update_cr)
{
        unsigned long flags;
        struct list_head *lh, *next;
        struct hpsb_address_serve *as;

        /* First, let the highlevel driver unreg */
        if (hl->remove_host)
                hl->remove_host(host);

        /* Remove any addresses that are matched for this highlevel driver
         * and this particular host. */
        write_lock_irqsave(&addr_space_lock, flags);
        list_for_each_safe (lh, next, &hl->addr_list) {
                as = list_entry(lh, struct hpsb_address_serve, hl_list);
                if (as->host == host)
                        __delete_addr(as);
        }
        write_unlock_irqrestore(&addr_space_lock, flags);

        /* Now update the config-rom to reflect anything removed by the
         * highlevel driver. */
        if (update_cr && host->update_config_rom &&
            hpsb_update_config_rom_image(host) < 0)
                HPSB_ERR("Failed to generate Configuration ROM image for host "
                         "%s-%d", hl->name, host->id);

        /* Finally remove all the host info associated between these two. */
        hpsb_destroy_hostinfo(hl, host);
}

static int highlevel_for_each_host_unreg(struct hpsb_host *host, void *__data)
{
        struct hpsb_highlevel *hl = __data;

        __unregister_host(hl, host, 1);
        return 0;
}

/**
 * hpsb_unregister_highlevel - unregister highlevel driver
 */
void hpsb_unregister_highlevel(struct hpsb_highlevel *hl)
{
        unsigned long flags;

        write_lock_irqsave(&hl_irqs_lock, flags);
        list_del(&hl->irq_list);
        write_unlock_irqrestore(&hl_irqs_lock, flags);

        down_write(&hl_drivers_sem);
        list_del(&hl->hl_list);
        up_write(&hl_drivers_sem);

        nodemgr_for_each_host(hl, highlevel_for_each_host_unreg);
}

/**
 * hpsb_allocate_and_register_addrspace - alloc' and reg' a host address space
 *
 * @start and @end are 48 bit pointers and have to be quadlet aligned.
 * @end points to the first address behind the handled addresses.  This
 * function can be called multiple times for a single hpsb_highlevel @hl to
 * implement sparse register sets.  The requested region must not overlap any
 * previously allocated region, otherwise registering will fail.
 *
 * It returns true for successful allocation.  Address spaces can be
 * unregistered with hpsb_unregister_addrspace.  All remaining address spaces
 * are automatically deallocated together with the hpsb_highlevel @hl.
 */
u64 hpsb_allocate_and_register_addrspace(struct hpsb_highlevel *hl,
                                         struct hpsb_host *host,
                                         const struct hpsb_address_ops *ops,
                                         u64 size, u64 alignment,
                                         u64 start, u64 end)
{
        struct hpsb_address_serve *as, *a1, *a2;
        struct list_head *entry;
        u64 retval = CSR1212_INVALID_ADDR_SPACE;
        unsigned long flags;
        u64 align_mask = ~(alignment - 1);

        if ((alignment & 3) || (alignment > 0x800000000000ULL) ||
            (hweight64(alignment) != 1)) {
                HPSB_ERR("%s called with invalid alignment: 0x%048llx",
                         __func__, (unsigned long long)alignment);
                return retval;
        }

        /* default range,
         * avoids controller's posted write area (see OHCI 1.1 clause 1.5) */
        if (start == CSR1212_INVALID_ADDR_SPACE &&
            end   == CSR1212_INVALID_ADDR_SPACE) {
                start = host->middle_addr_space;
                end   = CSR1212_ALL_SPACE_END;
        }

        if (((start|end) & ~align_mask) || (start >= end) ||
            (end > CSR1212_ALL_SPACE_END)) {
                HPSB_ERR("%s called with invalid addresses "
                         "(start = %012Lx  end = %012Lx)", __func__,
                         (unsigned long long)start,(unsigned long long)end);
                return retval;
        }

        as = kmalloc(sizeof(*as), GFP_KERNEL);
        if (!as)
                return retval;

        INIT_LIST_HEAD(&as->host_list);
        INIT_LIST_HEAD(&as->hl_list);
        as->op = ops;
        as->host = host;

        write_lock_irqsave(&addr_space_lock, flags);
        list_for_each(entry, &host->addr_space) {
                u64 a1sa, a1ea;
                u64 a2sa, a2ea;

                a1 = list_entry(entry, struct hpsb_address_serve, host_list);
                a2 = list_entry(entry->next, struct hpsb_address_serve,
                                host_list);

                a1sa = a1->start & align_mask;
                a1ea = (a1->end + alignment -1) & align_mask;
                a2sa = a2->start & align_mask;
                a2ea = (a2->end + alignment -1) & align_mask;

                if ((a2sa - a1ea >= size) && (a2sa - start >= size) &&
                    (a2sa > start)) {
                        as->start = max(start, a1ea);
                        as->end = as->start + size;
                        list_add(&as->host_list, entry);
                        list_add_tail(&as->hl_list, &hl->addr_list);
                        retval = as->start;
                        break;
                }
        }
        write_unlock_irqrestore(&addr_space_lock, flags);

        if (retval == CSR1212_INVALID_ADDR_SPACE)
                kfree(as);
        return retval;
}

/**
 * hpsb_register_addrspace - register a host address space
 *
 * @start and @end are 48 bit pointers and have to be quadlet aligned.
 * @end points to the first address behind the handled addresses.  This
 * function can be called multiple times for a single hpsb_highlevel @hl to
 * implement sparse register sets.  The requested region must not overlap any
 * previously allocated region, otherwise registering will fail.
 *
 * It returns true for successful allocation.  Address spaces can be
 * unregistered with hpsb_unregister_addrspace.  All remaining address spaces
 * are automatically deallocated together with the hpsb_highlevel @hl.
 */
int hpsb_register_addrspace(struct hpsb_highlevel *hl, struct hpsb_host *host,
                            const struct hpsb_address_ops *ops,
                            u64 start, u64 end)
{
        struct hpsb_address_serve *as;
        struct list_head *lh;
        int retval = 0;
        unsigned long flags;

        if (((start|end) & 3) || (start >= end) ||
            (end > CSR1212_ALL_SPACE_END)) {
                HPSB_ERR("%s called with invalid addresses", __func__);
                return 0;
        }

        as = kmalloc(sizeof(*as), GFP_KERNEL);
        if (!as)
                return 0;

        INIT_LIST_HEAD(&as->host_list);
        INIT_LIST_HEAD(&as->hl_list);
        as->op = ops;
        as->start = start;
        as->end = end;
        as->host = host;

        write_lock_irqsave(&addr_space_lock, flags);
        list_for_each(lh, &host->addr_space) {
                struct hpsb_address_serve *as_this =
                        list_entry(lh, struct hpsb_address_serve, host_list);
                struct hpsb_address_serve *as_next =
                        list_entry(lh->next, struct hpsb_address_serve,
                                   host_list);

                if (as_this->end > as->start)
                        break;

                if (as_next->start >= as->end) {
                        list_add(&as->host_list, lh);
                        list_add_tail(&as->hl_list, &hl->addr_list);
                        retval = 1;
                        break;
                }
        }
        write_unlock_irqrestore(&addr_space_lock, flags);

        if (retval == 0)
                kfree(as);
        return retval;
}

int hpsb_unregister_addrspace(struct hpsb_highlevel *hl, struct hpsb_host *host,
                              u64 start)
{
        int retval = 0;
        struct hpsb_address_serve *as;
        struct list_head *lh, *next;
        unsigned long flags;

        write_lock_irqsave(&addr_space_lock, flags);
        list_for_each_safe (lh, next, &hl->addr_list) {
                as = list_entry(lh, struct hpsb_address_serve, hl_list);
                if (as->start == start && as->host == host) {
                        __delete_addr(as);
                        retval = 1;
                        break;
                }
        }
        write_unlock_irqrestore(&addr_space_lock, flags);
        return retval;
}

const static struct hpsb_address_ops dummy_ops;

/* dummy address spaces as lower and upper bounds of the host's a.s. list */
static void init_hpsb_highlevel(struct hpsb_host *host)
{
        INIT_LIST_HEAD(&host->dummy_zero_addr.host_list);
        INIT_LIST_HEAD(&host->dummy_zero_addr.hl_list);
        INIT_LIST_HEAD(&host->dummy_max_addr.host_list);
        INIT_LIST_HEAD(&host->dummy_max_addr.hl_list);

        host->dummy_zero_addr.op = host->dummy_max_addr.op = &dummy_ops;

        host->dummy_zero_addr.start = host->dummy_zero_addr.end = 0;
        host->dummy_max_addr.start = host->dummy_max_addr.end = ((u64) 1) << 48;

        list_add_tail(&host->dummy_zero_addr.host_list, &host->addr_space);
        list_add_tail(&host->dummy_max_addr.host_list, &host->addr_space);
}

void highlevel_add_host(struct hpsb_host *host)
{
        struct hpsb_highlevel *hl;

        init_hpsb_highlevel(host);

        down_read(&hl_drivers_sem);
        list_for_each_entry(hl, &hl_drivers, hl_list) {
                if (hl->add_host)
                        hl->add_host(host);
        }
        up_read(&hl_drivers_sem);
        if (host->update_config_rom && hpsb_update_config_rom_image(host) < 0)
                HPSB_ERR("Failed to generate Configuration ROM image for host "
                         "%s-%d", hl->name, host->id);
}

void highlevel_remove_host(struct hpsb_host *host)
{
        struct hpsb_highlevel *hl;

        down_read(&hl_drivers_sem);
        list_for_each_entry(hl, &hl_drivers, hl_list)
                __unregister_host(hl, host, 0);
        up_read(&hl_drivers_sem);
}

void highlevel_host_reset(struct hpsb_host *host)
{
        unsigned long flags;
        struct hpsb_highlevel *hl;

        read_lock_irqsave(&hl_irqs_lock, flags);
        list_for_each_entry(hl, &hl_irqs, irq_list) {
                if (hl->host_reset)
                        hl->host_reset(host);
        }
        read_unlock_irqrestore(&hl_irqs_lock, flags);
}

void highlevel_fcp_request(struct hpsb_host *host, int nodeid, int direction,
                           void *data, size_t length)
{
        unsigned long flags;
        struct hpsb_highlevel *hl;
        int cts = ((quadlet_t *)data)[0] >> 4;

        read_lock_irqsave(&hl_irqs_lock, flags);
        list_for_each_entry(hl, &hl_irqs, irq_list) {
                if (hl->fcp_request)
                        hl->fcp_request(host, nodeid, direction, cts, data,
                                        length);
        }
        read_unlock_irqrestore(&hl_irqs_lock, flags);
}

/*
 * highlevel_read, highlevel_write, highlevel_lock, highlevel_lock64:
 *
 * These functions are called to handle transactions. They are called when a
 * packet arrives.  The flags argument contains the second word of the first
 * header quadlet of the incoming packet (containing transaction label, retry
 * code, transaction code and priority).  These functions either return a
 * response code or a negative number.  In the first case a response will be
 * generated.  In the latter case, no response will be sent and the driver which
 * handled the request will send the response itself.
 */
int highlevel_read(struct hpsb_host *host, int nodeid, void *data, u64 addr,
                   unsigned int length, u16 flags)
{
        struct hpsb_address_serve *as;
        unsigned int partlength;
        int rcode = RCODE_ADDRESS_ERROR;

        read_lock(&addr_space_lock);
        list_for_each_entry(as, &host->addr_space, host_list) {
                if (as->start > addr)
                        break;

                if (as->end > addr) {
                        partlength = min(as->end - addr, (u64) length);

                        if (as->op->read)
                                rcode = as->op->read(host, nodeid, data,
                                                     addr, partlength, flags);
                        else
                                rcode = RCODE_TYPE_ERROR;

                        data += partlength;
                        length -= partlength;
                        addr += partlength;

                        if ((rcode != RCODE_COMPLETE) || !length)
                                break;
                }
        }
        read_unlock(&addr_space_lock);

        if (length && (rcode == RCODE_COMPLETE))
                rcode = RCODE_ADDRESS_ERROR;
        return rcode;
}

int highlevel_write(struct hpsb_host *host, int nodeid, int destid, void *data,
                    u64 addr, unsigned int length, u16 flags)
{
        struct hpsb_address_serve *as;
        unsigned int partlength;
        int rcode = RCODE_ADDRESS_ERROR;

        read_lock(&addr_space_lock);
        list_for_each_entry(as, &host->addr_space, host_list) {
                if (as->start > addr)
                        break;

                if (as->end > addr) {
                        partlength = min(as->end - addr, (u64) length);

                        if (as->op->write)
                                rcode = as->op->write(host, nodeid, destid,
                                                      data, addr, partlength,
                                                      flags);
                        else
                                rcode = RCODE_TYPE_ERROR;

                        data += partlength;
                        length -= partlength;
                        addr += partlength;

                        if ((rcode != RCODE_COMPLETE) || !length)
                                break;
                }
        }
        read_unlock(&addr_space_lock);

        if (length && (rcode == RCODE_COMPLETE))
                rcode = RCODE_ADDRESS_ERROR;
        return rcode;
}

int highlevel_lock(struct hpsb_host *host, int nodeid, quadlet_t *store,
                   u64 addr, quadlet_t data, quadlet_t arg, int ext_tcode,
                   u16 flags)
{
        struct hpsb_address_serve *as;
        int rcode = RCODE_ADDRESS_ERROR;

        read_lock(&addr_space_lock);
        list_for_each_entry(as, &host->addr_space, host_list) {
                if (as->start > addr)
                        break;

                if (as->end > addr) {
                        if (as->op->lock)
                                rcode = as->op->lock(host, nodeid, store, addr,
                                                     data, arg, ext_tcode,
                                                     flags);
                        else
                                rcode = RCODE_TYPE_ERROR;
                        break;
                }
        }
        read_unlock(&addr_space_lock);
        return rcode;
}

int highlevel_lock64(struct hpsb_host *host, int nodeid, octlet_t *store,
                     u64 addr, octlet_t data, octlet_t arg, int ext_tcode,
                     u16 flags)
{
        struct hpsb_address_serve *as;
        int rcode = RCODE_ADDRESS_ERROR;

        read_lock(&addr_space_lock);

        list_for_each_entry(as, &host->addr_space, host_list) {
                if (as->start > addr)
                        break;

                if (as->end > addr) {
                        if (as->op->lock64)
                                rcode = as->op->lock64(host, nodeid, store,
                                                       addr, data, arg,
                                                       ext_tcode, flags);
                        else
                                rcode = RCODE_TYPE_ERROR;
                        break;
                }
        }
        read_unlock(&addr_space_lock);
        return rcode;
}