/*
 * Copyright (C) 2012-2013 Matteo Landi, Luigi Rizzo, Giuseppe Lettieri. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *   1. Redistributions of source code must retain the above copyright
 *      notice, this list of conditions and the following disclaimer.
 *   2. Redistributions in binary form must reproduce the above copyright
 *      notice, this list of conditions and the following disclaimer in the
 *      documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#include <sys/cdefs.h> /* prerequisite */
__FBSDID("$FreeBSD: head/sys/dev/netmap/netmap.c 241723 2012-10-19 09:41:45Z glebius $");

#include <sys/types.h>
#include <sys/malloc.h>
#include <sys/proc.h>
#include <vm/vm.h>      /* vtophys */
#include <vm/pmap.h>    /* vtophys */
#include <sys/socket.h> /* sockaddrs */
#include <sys/sysctl.h>
#include <net/if.h>
#include <net/if_var.h>
#include <sys/bus.h>    /* bus_dmamap_* */

#include <net/netmap/netmap.h>
#include <net/netmap/netmap_kern.h>
#include <net/netmap/netmap_mem2.h>

#define NMA_LOCK_INIT(n)        lockinit(&(n)->nm_mtx, "netmap memory allocator lock", 0, LK_CANRECURSE)
#define NMA_LOCK_DESTROY(n)     lockuninit(&(n)->nm_mtx)
#define NMA_LOCK(n)             lockmgr(&(n)->nm_mtx, LK_EXCLUSIVE)
#define NMA_UNLOCK(n)           lockmgr(&(n)->nm_mtx, LK_RELEASE)

struct netmap_obj_params netmap_params[NETMAP_POOLS_NR] = {
        [NETMAP_IF_POOL] = {
                .size = 1024,
                .num  = 100,
        },
        [NETMAP_RING_POOL] = {
                .size = 9*PAGE_SIZE,
                .num  = 200,
        },
        [NETMAP_BUF_POOL] = {
                .size = 2048,
                .num  = NETMAP_BUF_MAX_NUM,
        },
};


/*
 * nm_mem is the memory allocator used for all physical interfaces
 * running in netmap mode.
 * Virtual (VALE) ports will have each its own allocator.
 */
static int netmap_mem_global_config(struct netmap_mem_d *nmd);
static int netmap_mem_global_finalize(struct netmap_mem_d *nmd);
static void netmap_mem_global_deref(struct netmap_mem_d *nmd);
struct netmap_mem_d nm_mem = {  /* Our memory allocator. */
        .pools = {
                [NETMAP_IF_POOL] = {
                        .name   = "netmap_if",
                        .objminsize = sizeof(struct netmap_if),
                        .objmaxsize = 4096,
                        .nummin     = 10,       /* don't be stingy */
                        .nummax     = 10000,    /* XXX very large */
                },
                [NETMAP_RING_POOL] = {
                        .name   = "netmap_ring",
                        .objminsize = sizeof(struct netmap_ring),
                        .objmaxsize = 32*PAGE_SIZE,
                        .nummin     = 2,
                        .nummax     = 1024,
                },
                [NETMAP_BUF_POOL] = {
                        .name   = "netmap_buf",
                        .objminsize = 64,
                        .objmaxsize = 65536,
                        .nummin     = 4,
                        .nummax     = 1000000, /* one million! */
                },
        },
        .config   = netmap_mem_global_config,
        .finalize = netmap_mem_global_finalize,
        .deref    = netmap_mem_global_deref,
};


// XXX logically belongs to nm_mem
struct lut_entry *netmap_buffer_lut;    /* exported */

/* blueprint for the private memory allocators */
static int netmap_mem_private_config(struct netmap_mem_d *nmd);
static int netmap_mem_private_finalize(struct netmap_mem_d *nmd);
static void netmap_mem_private_deref(struct netmap_mem_d *nmd);
const struct netmap_mem_d nm_blueprint = {
        .pools = {
                [NETMAP_IF_POOL] = {
                        .name   = "%s_if",
                        .objminsize = sizeof(struct netmap_if),
                        .objmaxsize = 4096,
                        .nummin     = 1,
                        .nummax     = 10,
                },
                [NETMAP_RING_POOL] = {
                        .name   = "%s_ring",
                        .objminsize = sizeof(struct netmap_ring),
                        .objmaxsize = 32*PAGE_SIZE,
                        .nummin     = 2,
                        .nummax     = 1024,
                },
                [NETMAP_BUF_POOL] = {
                        .name   = "%s_buf",
                        .objminsize = 64,
                        .objmaxsize = 65536,
                        .nummin     = 4,
                        .nummax     = 1000000, /* one million! */
                },
        },
        .config   = netmap_mem_private_config,
        .finalize = netmap_mem_private_finalize,
        .deref    = netmap_mem_private_deref,

        .flags = NETMAP_MEM_PRIVATE,
};

/* memory allocator related sysctls */

#define STRINGIFY(x) #x


#define DECLARE_SYSCTLS(id, name) \
        SYSCTL_INT(_dev_netmap, OID_AUTO, name##_size, \
            CTLFLAG_RW, &netmap_params[id].size, 0, "Requested size of netmap " STRINGIFY(name) "s"); \
        SYSCTL_INT(_dev_netmap, OID_AUTO, name##_curr_size, \
            CTLFLAG_RD, &nm_mem.pools[id]._objsize, 0, "Current size of netmap " STRINGIFY(name) "s"); \
        SYSCTL_INT(_dev_netmap, OID_AUTO, name##_num, \
            CTLFLAG_RW, &netmap_params[id].num, 0, "Requested number of netmap " STRINGIFY(name) "s"); \
        SYSCTL_INT(_dev_netmap, OID_AUTO, name##_curr_num, \
            CTLFLAG_RD, &nm_mem.pools[id].objtotal, 0, "Current number of netmap " STRINGIFY(name) "s")

SYSCTL_DECL(_dev_netmap);
DECLARE_SYSCTLS(NETMAP_IF_POOL, if);
DECLARE_SYSCTLS(NETMAP_RING_POOL, ring);
DECLARE_SYSCTLS(NETMAP_BUF_POOL, buf);

/*
 * First, find the allocator that contains the requested offset,
 * then locate the cluster through a lookup table.
 */
vm_paddr_t
netmap_mem_ofstophys(struct netmap_mem_d* nmd, vm_ooffset_t offset)
{
        int i;
        vm_ooffset_t o = offset;
        vm_paddr_t pa;
        struct netmap_obj_pool *p;

        NMA_LOCK(nmd);
        p = nmd->pools;

        for (i = 0; i < NETMAP_POOLS_NR; offset -= p[i].memtotal, i++) {
                if (offset >= p[i].memtotal)
                        continue;
                // now lookup the cluster's address
                pa = p[i].lut[offset / p[i]._objsize].paddr +
                        offset % p[i]._objsize;
                NMA_UNLOCK(nmd);
                return pa;
        }
        /* this is only in case of errors */
        D("invalid ofs 0x%x out of 0x%x 0x%x 0x%x", (u_int)o,
                p[NETMAP_IF_POOL].memtotal,
                p[NETMAP_IF_POOL].memtotal
                        + p[NETMAP_RING_POOL].memtotal,
                p[NETMAP_IF_POOL].memtotal
                        + p[NETMAP_RING_POOL].memtotal
                        + p[NETMAP_BUF_POOL].memtotal);
        NMA_UNLOCK(nmd);
        return 0;       // XXX bad address
}

int
netmap_mem_get_info(struct netmap_mem_d* nmd, u_int* size, u_int *memflags)
{
        int error = 0;
        NMA_LOCK(nmd);
        error = nmd->config(nmd);
        if (error)
                goto out;
        if (nmd->flags & NETMAP_MEM_FINALIZED) {
                *size = nmd->nm_totalsize;
        } else {
                int i;
                *size = 0;
                for (i = 0; i < NETMAP_POOLS_NR; i++) {
                        struct netmap_obj_pool *p = nmd->pools + i;
                        *size += (p->_numclusters * p->_clustsize);
                }
        }
        *memflags = nmd->flags;
out:
        NMA_UNLOCK(nmd);
        return error;
}

/*
 * we store objects by kernel address, need to find the offset
 * within the pool to export the value to userspace.
 * Algorithm: scan until we find the cluster, then add the
 * actual offset in the cluster
 */
static ssize_t
netmap_obj_offset(struct netmap_obj_pool *p, const void *vaddr)
{
        int i, k = p->_clustentries, n = p->objtotal;
        ssize_t ofs = 0;

        for (i = 0; i < n; i += k, ofs += p->_clustsize) {
                const char *base = p->lut[i].vaddr;
                ssize_t relofs = (const char *) vaddr - base;

                if (relofs < 0 || relofs >= p->_clustsize)
                        continue;

                ofs = ofs + relofs;
                ND("%s: return offset %d (cluster %d) for pointer %p",
                    p->name, ofs, i, vaddr);
                return ofs;
        }
        D("address %p is not contained inside any cluster (%s)",
            vaddr, p->name);
        return 0; /* An error occurred */
}

/* Helper functions which convert virtual addresses to offsets */
#define netmap_if_offset(n, v)                                  \
        netmap_obj_offset(&(n)->pools[NETMAP_IF_POOL], (v))

#define netmap_ring_offset(n, v)                                \
    ((n)->pools[NETMAP_IF_POOL].memtotal +                      \
        netmap_obj_offset(&(n)->pools[NETMAP_RING_POOL], (v)))

#define netmap_buf_offset(n, v)                                 \
    ((n)->pools[NETMAP_IF_POOL].memtotal +                      \
        (n)->pools[NETMAP_RING_POOL].memtotal +         \
        netmap_obj_offset(&(n)->pools[NETMAP_BUF_POOL], (v)))


ssize_t
netmap_mem_if_offset(struct netmap_mem_d *nmd, const void *addr)
{
        ssize_t v;
        NMA_LOCK(nmd);
        v = netmap_if_offset(nmd, addr);
        NMA_UNLOCK(nmd);
        return v;
}

/*
 * report the index, and use start position as a hint,
 * otherwise buffer allocation becomes terribly expensive.
 */
static void *
netmap_obj_malloc(struct netmap_obj_pool *p, u_int len, uint32_t *start, uint32_t *index)
{
        uint32_t i = 0;                 /* index in the bitmap */
        uint32_t mask, j;               /* slot counter */
        void *vaddr = NULL;

        if (len > p->_objsize) {
                D("%s request size %d too large", p->name, len);
                // XXX cannot reduce the size
                return NULL;
        }

        if (p->objfree == 0) {
                D("%s allocator: run out of memory", p->name);
                return NULL;
        }
        if (start)
                i = *start;

        /* termination is guaranteed by p->free, but better check bounds on i */
        while (vaddr == NULL && i < p->bitmap_slots)  {
                uint32_t cur = p->bitmap[i];
                if (cur == 0) { /* bitmask is fully used */
                        i++;
                        continue;
                }
                /* locate a slot */
                for (j = 0, mask = 1; (cur & mask) == 0; j++, mask <<= 1)
                        ;

                p->bitmap[i] &= ~mask; /* mark object as in use */
                p->objfree--;

                vaddr = p->lut[i * 32 + j].vaddr;
                if (index)
                        *index = i * 32 + j;
        }
        ND("%s allocator: allocated object @ [%d][%d]: vaddr %p", i, j, vaddr);

        if (start)
                *start = i;
        return vaddr;
}


/*
 * free by index, not by address. This is slow, but is only used
 * for a small number of objects (rings, nifp)
 */
static void
netmap_obj_free(struct netmap_obj_pool *p, uint32_t j)
{
        if (j >= p->objtotal) {
                D("invalid index %u, max %u", j, p->objtotal);
                return;
        }
        p->bitmap[j / 32] |= (1 << (j % 32));
        p->objfree++;
        return;
}

static void
netmap_obj_free_va(struct netmap_obj_pool *p, void *vaddr)
{
        u_int i, j, n = p->numclusters;

        for (i = 0, j = 0; i < n; i++, j += p->_clustentries) {
                void *base = p->lut[i * p->_clustentries].vaddr;
                ssize_t relofs = (ssize_t) vaddr - (ssize_t) base;

                /* Given address, is out of the scope of the current cluster.*/
                if (vaddr < base || relofs >= p->_clustsize)
                        continue;

                j = j + relofs / p->_objsize;
                /* KASSERT(j != 0, ("Cannot free object 0")); */
                netmap_obj_free(p, j);
                return;
        }
        D("address %p is not contained inside any cluster (%s)",
            vaddr, p->name);
}

#define netmap_if_malloc(n, len)        netmap_obj_malloc(&(n)->pools[NETMAP_IF_POOL], len, NULL, NULL)
#define netmap_if_free(n, v)            netmap_obj_free_va(&(n)->pools[NETMAP_IF_POOL], (v))
#define netmap_ring_malloc(n, len)      netmap_obj_malloc(&(n)->pools[NETMAP_RING_POOL], len, NULL, NULL)
#define netmap_ring_free(n, v)          netmap_obj_free_va(&(n)->pools[NETMAP_RING_POOL], (v))
#define netmap_buf_malloc(n, _pos, _index)                      \
        netmap_obj_malloc(&(n)->pools[NETMAP_BUF_POOL], NETMAP_BDG_BUF_SIZE(n), _pos, _index)


/* Return the index associated to the given packet buffer */
#define netmap_buf_index(n, v)                                          \
    (netmap_obj_offset(&(n)->pools[NETMAP_BUF_POOL], (v)) / NETMAP_BDG_BUF_SIZE(n))


/* Return nonzero on error */
static int
netmap_new_bufs(struct netmap_mem_d *nmd, struct netmap_slot *slot, u_int n)
{
        struct netmap_obj_pool *p = &nmd->pools[NETMAP_BUF_POOL];
        u_int i = 0;    /* slot counter */
        uint32_t pos = 0;       /* slot in p->bitmap */
        uint32_t index = 0;     /* buffer index */

        for (i = 0; i < n; i++) {
                void *vaddr = netmap_buf_malloc(nmd, &pos, &index);
                if (vaddr == NULL) {
                        D("unable to locate empty packet buffer");
                        goto cleanup;
                }
                slot[i].buf_idx = index;
                slot[i].len = p->_objsize;
                /* XXX setting flags=NS_BUF_CHANGED forces a pointer reload
                 * in the NIC ring. This is a hack that hides missing
                 * initializations in the drivers, and should go away.
                 */
                // slot[i].flags = NS_BUF_CHANGED;
        }

        ND("allocated %d buffers, %d available, first at %d", n, p->objfree, pos);
        return (0);

cleanup:
        while (i > 0) {
                i--;
                netmap_obj_free(p, slot[i].buf_idx);
        }
        bzero(slot, n * sizeof(slot[0]));
        return (ENOMEM);
}


static void
netmap_free_buf(struct netmap_mem_d *nmd, uint32_t i)
{
        struct netmap_obj_pool *p = &nmd->pools[NETMAP_BUF_POOL];

        if (i < 2 || i >= p->objtotal) {
                D("Cannot free buf#%d: should be in [2, %d[", i, p->objtotal);
                return;
        }
        netmap_obj_free(p, i);
}

static void
netmap_reset_obj_allocator(struct netmap_obj_pool *p)
{

        if (p == NULL)
                return;
        if (p->bitmap)
                kfree(p->bitmap, M_NETMAP);
        p->bitmap = NULL;
        if (p->lut) {
                u_int i;
                size_t sz = p->_clustsize;

                for (i = 0; i < p->objtotal; i += p->_clustentries) {
                        if (p->lut[i].vaddr)
                                contigfree(p->lut[i].vaddr, sz, M_NETMAP);
                }
                bzero(p->lut, sizeof(struct lut_entry) * p->objtotal);
                kfree(p->lut, M_NETMAP);
        }
        p->lut = NULL;
        p->objtotal = 0;
        p->memtotal = 0;
        p->numclusters = 0;
        p->objfree = 0;
}

/*
 * Free all resources related to an allocator.
 */
static void
netmap_destroy_obj_allocator(struct netmap_obj_pool *p)
{
        if (p == NULL)
                return;
        netmap_reset_obj_allocator(p);
}

/*
 * We receive a request for objtotal objects, of size objsize each.
 * Internally we may round up both numbers, as we allocate objects
 * in small clusters multiple of the page size.
 * We need to keep track of objtotal and clustentries,
 * as they are needed when freeing memory.
 *
 * XXX note -- userspace needs the buffers to be contiguous,
 *      so we cannot afford gaps at the end of a cluster.
 */


/* call with NMA_LOCK held */
static int
netmap_config_obj_allocator(struct netmap_obj_pool *p, u_int objtotal, u_int objsize)
{
        int i;
        u_int clustsize;        /* the cluster size, multiple of page size */
        u_int clustentries;     /* how many objects per entry */

        /* we store the current request, so we can
         * detect configuration changes later */
        p->r_objtotal = objtotal;
        p->r_objsize = objsize;

#define MAX_CLUSTSIZE   (1<<17)
#define LINE_ROUND      64
        if (objsize >= MAX_CLUSTSIZE) {
                /* we could do it but there is no point */
                D("unsupported allocation for %d bytes", objsize);
                return EINVAL;
        }
        /* make sure objsize is a multiple of LINE_ROUND */
        i = (objsize & (LINE_ROUND - 1));
        if (i) {
                D("XXX aligning object by %d bytes", LINE_ROUND - i);
                objsize += LINE_ROUND - i;
        }
        if (objsize < p->objminsize || objsize > p->objmaxsize) {
                D("requested objsize %d out of range [%d, %d]",
                        objsize, p->objminsize, p->objmaxsize);
                return EINVAL;
        }
        if (objtotal < p->nummin || objtotal > p->nummax) {
                D("requested objtotal %d out of range [%d, %d]",
                        objtotal, p->nummin, p->nummax);
                return EINVAL;
        }
        /*
         * Compute number of objects using a brute-force approach:
         * given a max cluster size,
         * we try to fill it with objects keeping track of the
         * wasted space to the next page boundary.
         */
        for (clustentries = 0, i = 1;; i++) {
                u_int delta, used = i * objsize;
                if (used > MAX_CLUSTSIZE)
                        break;
                delta = used % PAGE_SIZE;
                if (delta == 0) { // exact solution
                        clustentries = i;
                        break;
                }
                if (delta > ( (clustentries*objsize) % PAGE_SIZE) )
                        clustentries = i;
        }
        // D("XXX --- ouch, delta %d (bad for buffers)", delta);
        /* compute clustsize and round to the next page */
        clustsize = clustentries * objsize;
        i =  (clustsize & (PAGE_SIZE - 1));
        if (i)
                clustsize += PAGE_SIZE - i;
        if (netmap_verbose)
                D("objsize %d clustsize %d objects %d",
                        objsize, clustsize, clustentries);

        /*
         * The number of clusters is n = ceil(objtotal/clustentries)
         * objtotal' = n * clustentries
         */
        p->_clustentries = clustentries;
        p->_clustsize = clustsize;
        p->_numclusters = (objtotal + clustentries - 1) / clustentries;

        /* actual values (may be larger than requested) */
        p->_objsize = objsize;
        p->_objtotal = p->_numclusters * clustentries;

        return 0;
}


/* call with NMA_LOCK held */
static int
netmap_finalize_obj_allocator(struct netmap_obj_pool *p)
{
        int i; /* must be signed */
        size_t n;

        /* optimistically assume we have enough memory */
        p->numclusters = p->_numclusters;
        p->objtotal = p->_objtotal;

        n = sizeof(struct lut_entry) * p->objtotal;
        p->lut = kmalloc(n, M_NETMAP, M_NOWAIT | M_ZERO);
        if (p->lut == NULL) {
                D("Unable to create lookup table (%d bytes) for '%s'", (int)n, p->name);
                goto clean;
        }

        /* Allocate the bitmap */
        n = (p->objtotal + 31) / 32;
        p->bitmap = kmalloc(sizeof(uint32_t) * n, M_NETMAP, M_NOWAIT | M_ZERO);
        if (p->bitmap == NULL) {
                D("Unable to create bitmap (%d entries) for allocator '%s'", (int)n,
                    p->name);
                goto clean;
        }
        p->bitmap_slots = n;

        /*
         * Allocate clusters, init pointers and bitmap
         */

        n = p->_clustsize;
        for (i = 0; i < (int)p->objtotal;) {
                int lim = i + p->_clustentries;
                char *clust;

                clust = contigmalloc(n, M_NETMAP, M_NOWAIT | M_ZERO,
                    (size_t)0, -1UL, PAGE_SIZE, 0);
                if (clust == NULL) {
                        /*
                         * If we get here, there is a severe memory shortage,
                         * so halve the allocated memory to reclaim some.
                         */
                        D("Unable to create cluster at %d for '%s' allocator",
                            i, p->name);
                        if (i < 2) /* nothing to halve */
                                goto out;
                        lim = i / 2;
                        for (i--; i >= lim; i--) {
                                p->bitmap[ (i>>5) ] &=  ~( 1 << (i & 31) );
                                if (i % p->_clustentries == 0 && p->lut[i].vaddr)
                                        contigfree(p->lut[i].vaddr,
                                                n, M_NETMAP);
                        }
                out:
                        p->objtotal = i;
                        /* we may have stopped in the middle of a cluster */
                        p->numclusters = (i + p->_clustentries - 1) / p->_clustentries;
                        break;
                }
                for (; i < lim; i++, clust += p->_objsize) {
                        p->bitmap[ (i>>5) ] |=  ( 1 << (i & 31) );
                        p->lut[i].vaddr = clust;
                        p->lut[i].paddr = vtophys(clust);
                }
        }
        p->objfree = p->objtotal;
        p->memtotal = p->numclusters * p->_clustsize;
        if (p->objfree == 0)
                goto clean;
        if (netmap_verbose)
                D("Pre-allocated %d clusters (%d/%dKB) for '%s'",
                    p->numclusters, p->_clustsize >> 10,
                    p->memtotal >> 10, p->name);

        return 0;

clean:
        netmap_reset_obj_allocator(p);
        return ENOMEM;
}

/* call with lock held */
static int
netmap_memory_config_changed(struct netmap_mem_d *nmd)
{
        int i;

        for (i = 0; i < NETMAP_POOLS_NR; i++) {
                if (nmd->pools[i].r_objsize != netmap_params[i].size ||
                    nmd->pools[i].r_objtotal != netmap_params[i].num)
                    return 1;
        }
        return 0;
}

static void
netmap_mem_reset_all(struct netmap_mem_d *nmd)
{
        int i;
        D("resetting %p", nmd);
        for (i = 0; i < NETMAP_POOLS_NR; i++) {
                netmap_reset_obj_allocator(&nmd->pools[i]);
        }
        nmd->flags  &= ~NETMAP_MEM_FINALIZED;
}

static int
netmap_mem_finalize_all(struct netmap_mem_d *nmd)
{
        int i;
        if (nmd->flags & NETMAP_MEM_FINALIZED)
                return 0;
        nmd->lasterr = 0;
        nmd->nm_totalsize = 0;
        for (i = 0; i < NETMAP_POOLS_NR; i++) {
                nmd->lasterr = netmap_finalize_obj_allocator(&nmd->pools[i]);
                if (nmd->lasterr)
                        goto error;
                nmd->nm_totalsize += nmd->pools[i].memtotal;
        }
        /* buffers 0 and 1 are reserved */
        nmd->pools[NETMAP_BUF_POOL].objfree -= 2;
        nmd->pools[NETMAP_BUF_POOL].bitmap[0] = ~3;
        nmd->flags |= NETMAP_MEM_FINALIZED;

        D("Have %d KB for interfaces, %d KB for rings and %d MB for buffers",
            nmd->pools[NETMAP_IF_POOL].memtotal >> 10,
            nmd->pools[NETMAP_RING_POOL].memtotal >> 10,
            nmd->pools[NETMAP_BUF_POOL].memtotal >> 20);

        D("Free buffers: %d", nmd->pools[NETMAP_BUF_POOL].objfree);


        return 0;
error:
        netmap_mem_reset_all(nmd);
        return nmd->lasterr;
}



void
netmap_mem_private_delete(struct netmap_mem_d *nmd)
{
        if (nmd == NULL)
                return;
        D("deleting %p", nmd);
        if (nmd->refcount > 0)
                D("bug: deleting mem allocator with refcount=%d!", nmd->refcount);
        D("done deleting %p", nmd);
        NMA_LOCK_DESTROY(nmd);
        kfree(nmd, M_DEVBUF);
}

static int
netmap_mem_private_config(struct netmap_mem_d *nmd)
{
        /* nothing to do, we are configured on creation
         * and configuration never changes thereafter
         */
        return 0;
}

static int
netmap_mem_private_finalize(struct netmap_mem_d *nmd)
{
        int err;
        NMA_LOCK(nmd);
        nmd->refcount++;
        err = netmap_mem_finalize_all(nmd);
        NMA_UNLOCK(nmd);
        return err;

}

static void
netmap_mem_private_deref(struct netmap_mem_d *nmd)
{
        NMA_LOCK(nmd);
        if (--nmd->refcount <= 0)
                netmap_mem_reset_all(nmd);
        NMA_UNLOCK(nmd);
}

struct netmap_mem_d *
netmap_mem_private_new(const char *name, u_int txr, u_int txd, u_int rxr, u_int rxd)
{
        struct netmap_mem_d *d = NULL;
        struct netmap_obj_params p[NETMAP_POOLS_NR];
        int i;
        u_int maxd;

        d = kmalloc(sizeof(struct netmap_mem_d),
                        M_DEVBUF, M_NOWAIT | M_ZERO);
        if (d == NULL)
                return NULL;

        *d = nm_blueprint;

        /* XXX the rest of the code assumes the stack rings are alwasy present */
        txr++;
        rxr++;
        p[NETMAP_IF_POOL].size = sizeof(struct netmap_if) +
                sizeof(ssize_t) * (txr + rxr);
        p[NETMAP_IF_POOL].num = 2;
        maxd = (txd > rxd) ? txd : rxd;
        p[NETMAP_RING_POOL].size = sizeof(struct netmap_ring) +
                sizeof(struct netmap_slot) * maxd;
        p[NETMAP_RING_POOL].num = txr + rxr;
        p[NETMAP_BUF_POOL].size = 2048; /* XXX find a way to let the user choose this */
        p[NETMAP_BUF_POOL].num = rxr * (rxd + 2) + txr * (txd + 2);

        D("req if %d*%d ring %d*%d buf %d*%d",
                        p[NETMAP_IF_POOL].num,
                        p[NETMAP_IF_POOL].size,
                        p[NETMAP_RING_POOL].num,
                        p[NETMAP_RING_POOL].size,
                        p[NETMAP_BUF_POOL].num,
                        p[NETMAP_BUF_POOL].size);

        for (i = 0; i < NETMAP_POOLS_NR; i++) {
                ksnprintf(d->pools[i].name, NETMAP_POOL_MAX_NAMSZ,
                                nm_blueprint.pools[i].name,
                                name);
                if (netmap_config_obj_allocator(&d->pools[i],
                                p[i].num, p[i].size))
                        goto error;
        }

        d->flags &= ~NETMAP_MEM_FINALIZED;

        NMA_LOCK_INIT(d);

        return d;
error:
        netmap_mem_private_delete(d);
        return NULL;
}


/* call with lock held */
static int
netmap_mem_global_config(struct netmap_mem_d *nmd)
{
        int i;

        if (nmd->refcount)
                /* already in use, we cannot change the configuration */
                goto out;

        if (!netmap_memory_config_changed(nmd))
                goto out;

        D("reconfiguring");

        if (nmd->flags & NETMAP_MEM_FINALIZED) {
                /* reset previous allocation */
                for (i = 0; i < NETMAP_POOLS_NR; i++) {
                        netmap_reset_obj_allocator(&nmd->pools[i]);
                }
                nmd->flags &= ~NETMAP_MEM_FINALIZED;
        }

        for (i = 0; i < NETMAP_POOLS_NR; i++) {
                nmd->lasterr = netmap_config_obj_allocator(&nmd->pools[i],
                                netmap_params[i].num, netmap_params[i].size);
                if (nmd->lasterr)
                        goto out;
        }

out:

        return nmd->lasterr;
}

static int
netmap_mem_global_finalize(struct netmap_mem_d *nmd)
{
        int err;

        NMA_LOCK(nmd);


        /* update configuration if changed */
        if (netmap_mem_global_config(nmd))
                goto out;

        nmd->refcount++;

        if (nmd->flags & NETMAP_MEM_FINALIZED) {
                /* may happen if config is not changed */
                ND("nothing to do");
                goto out;
        }

        if (netmap_mem_finalize_all(nmd))
                goto out;

        /* backward compatibility */
        netmap_buf_size = nmd->pools[NETMAP_BUF_POOL]._objsize;
        netmap_total_buffers = nmd->pools[NETMAP_BUF_POOL].objtotal;

        netmap_buffer_lut = nmd->pools[NETMAP_BUF_POOL].lut;
        netmap_buffer_base = nmd->pools[NETMAP_BUF_POOL].lut[0].vaddr;

        nmd->lasterr = 0;

out:
        if (nmd->lasterr)
                nmd->refcount--;
        err = nmd->lasterr;

        NMA_UNLOCK(nmd);

        return err;

}

int
netmap_mem_init(void)
{
        NMA_LOCK_INIT(&nm_mem);
        return (0);
}

void
netmap_mem_fini(void)
{
        int i;

        for (i = 0; i < NETMAP_POOLS_NR; i++) {
            netmap_destroy_obj_allocator(&nm_mem.pools[i]);
        }
        NMA_LOCK_DESTROY(&nm_mem);
}

static void
netmap_free_rings(struct netmap_adapter *na)
{
        u_int i;
        if (!na->tx_rings)
                return;
        for (i = 0; i < na->num_tx_rings + 1; i++) {
                if (na->tx_rings[i].ring) {
                        netmap_ring_free(na->nm_mem, na->tx_rings[i].ring);
                        na->tx_rings[i].ring = NULL;
                }
        }
        for (i = 0; i < na->num_rx_rings + 1; i++) {
                if (na->rx_rings[i].ring) {
                        netmap_ring_free(na->nm_mem, na->rx_rings[i].ring);
                        na->rx_rings[i].ring = NULL;
                }
        }
}

/* call with NMA_LOCK held *
 *
 * Allocate netmap rings and buffers for this card
 * The rings are contiguous, but have variable size.
 */
int
netmap_mem_rings_create(struct netmap_adapter *na)
{
        struct netmap_ring *ring;
        u_int len, ndesc;
        struct netmap_kring *kring;

        NMA_LOCK(na->nm_mem);

        for (kring = na->tx_rings; kring != na->rx_rings; kring++) { /* Transmit rings */
                ndesc = kring->nkr_num_slots;
                len = sizeof(struct netmap_ring) +
                          ndesc * sizeof(struct netmap_slot);
                ring = netmap_ring_malloc(na->nm_mem, len);
                if (ring == NULL) {
                        D("Cannot allocate tx_ring");
                        goto cleanup;
                }
                ND("txring[%d] at %p ofs %d", i, ring);
                kring->ring = ring;
                *(uint32_t *)(uintptr_t)&ring->num_slots = ndesc;
                *(ssize_t *)(uintptr_t)&ring->buf_ofs =
                    (na->nm_mem->pools[NETMAP_IF_POOL].memtotal +
                        na->nm_mem->pools[NETMAP_RING_POOL].memtotal) -
                        netmap_ring_offset(na->nm_mem, ring);

                ring->avail = kring->nr_hwavail;
                ring->cur = kring->nr_hwcur;
                *(uint16_t *)(uintptr_t)&ring->nr_buf_size =
                        NETMAP_BDG_BUF_SIZE(na->nm_mem);
                ND("initializing slots for txring");
                if (netmap_new_bufs(na->nm_mem, ring->slot, ndesc)) {
                        D("Cannot allocate buffers for tx_ring");
                        goto cleanup;
                }
        }

        for ( ; kring != na->tailroom; kring++) { /* Receive rings */
                ndesc = kring->nkr_num_slots;
                len = sizeof(struct netmap_ring) +
                          ndesc * sizeof(struct netmap_slot);
                ring = netmap_ring_malloc(na->nm_mem, len);
                if (ring == NULL) {
                        D("Cannot allocate rx_ring");
                        goto cleanup;
                }
                ND("rxring at %p ofs %d", ring);

                kring->ring = ring;
                *(uint32_t *)(uintptr_t)&ring->num_slots = ndesc;
                *(ssize_t *)(uintptr_t)&ring->buf_ofs =
                    (na->nm_mem->pools[NETMAP_IF_POOL].memtotal +
                        na->nm_mem->pools[NETMAP_RING_POOL].memtotal) -
                        netmap_ring_offset(na->nm_mem, ring);

                ring->cur = kring->nr_hwcur;
                ring->avail = kring->nr_hwavail;
                *(int *)(uintptr_t)&ring->nr_buf_size =
                        NETMAP_BDG_BUF_SIZE(na->nm_mem);
                ND("initializing slots for rxring[%d]", i);
                if (netmap_new_bufs(na->nm_mem, ring->slot, ndesc)) {
                        D("Cannot allocate buffers for rx_ring");
                        goto cleanup;
                }
        }

        NMA_UNLOCK(na->nm_mem);

        return 0;

cleanup:
        netmap_free_rings(na);

        NMA_UNLOCK(na->nm_mem);

        return ENOMEM;
}

void
netmap_mem_rings_delete(struct netmap_adapter *na)
{
        /* last instance, release bufs and rings */
        u_int i, lim;
        struct netmap_kring *kring;
        struct netmap_ring *ring;

        NMA_LOCK(na->nm_mem);

        for (kring = na->tx_rings; kring != na->tailroom; kring++) {
                ring = kring->ring;
                if (ring == NULL)
                        continue;
                lim = kring->nkr_num_slots;
                for (i = 0; i < lim; i++)
                        netmap_free_buf(na->nm_mem, ring->slot[i].buf_idx);
        }
        netmap_free_rings(na);

        NMA_UNLOCK(na->nm_mem);
}


/* call with NMA_LOCK held */
/*
 * Allocate the per-fd structure netmap_if.
 *
 * We assume that the configuration stored in na
 * (number of tx/rx rings and descs) does not change while
 * the interface is in netmap mode.
 */
struct netmap_if *
netmap_mem_if_new(const char *ifname, struct netmap_adapter *na)
{
        struct netmap_if *nifp;
        ssize_t base; /* handy for relative offsets between rings and nifp */
        u_int i, len, ntx, nrx;

        /*
         * verify whether virtual port need the stack ring
         */
        ntx = na->num_tx_rings + 1; /* shorthand, include stack ring */
        nrx = na->num_rx_rings + 1; /* shorthand, include stack ring */
        /*
         * the descriptor is followed inline by an array of offsets
         * to the tx and rx rings in the shared memory region.
         * For virtual rx rings we also allocate an array of
         * pointers to assign to nkr_leases.
         */

        NMA_LOCK(na->nm_mem);

        len = sizeof(struct netmap_if) + (nrx + ntx) * sizeof(ssize_t);
        nifp = netmap_if_malloc(na->nm_mem, len);
        if (nifp == NULL) {
                NMA_UNLOCK(na->nm_mem);
                return NULL;
        }

        /* initialize base fields -- override const */
        *(u_int *)(uintptr_t)&nifp->ni_tx_rings = na->num_tx_rings;
        *(u_int *)(uintptr_t)&nifp->ni_rx_rings = na->num_rx_rings;
        strncpy(nifp->ni_name, ifname, (size_t)IFNAMSIZ);

        /*
         * fill the slots for the rx and tx rings. They contain the offset
         * between the ring and nifp, so the information is usable in
         * userspace to reach the ring from the nifp.
         */
        base = netmap_if_offset(na->nm_mem, nifp);
        for (i = 0; i < ntx; i++) {
                *(ssize_t *)(uintptr_t)&nifp->ring_ofs[i] =
                        netmap_ring_offset(na->nm_mem, na->tx_rings[i].ring) - base;
        }
        for (i = 0; i < nrx; i++) {
                *(ssize_t *)(uintptr_t)&nifp->ring_ofs[i+ntx] =
                        netmap_ring_offset(na->nm_mem, na->rx_rings[i].ring) - base;
        }

        NMA_UNLOCK(na->nm_mem);

        return (nifp);
}

void
netmap_mem_if_delete(struct netmap_adapter *na, struct netmap_if *nifp)
{
        if (nifp == NULL)
                /* nothing to do */
                return;
        NMA_LOCK(na->nm_mem);

        netmap_if_free(na->nm_mem, nifp);

        NMA_UNLOCK(na->nm_mem);
}

static void
netmap_mem_global_deref(struct netmap_mem_d *nmd)
{
        NMA_LOCK(nmd);

        nmd->refcount--;
        if (netmap_verbose)
                D("refcount = %d", nmd->refcount);

        NMA_UNLOCK(nmd);
}

int
netmap_mem_finalize(struct netmap_mem_d *nmd)
{
        return nmd->finalize(nmd);
}

void
netmap_mem_deref(struct netmap_mem_d *nmd)
{
        return nmd->deref(nmd);
}