svn commit: r235561 - stable/9/sys/dev/netmap
Luigi Rizzo
luigi at FreeBSD.org
Thu May 17 20:04:25 UTC 2012
Author: luigi
Date: Thu May 17 20:04:24 2012
New Revision: 235561
URL: http://svn.freebsd.org/changeset/base/235561
Log:
forgot two files in the previous commit...
Added:
stable/9/sys/dev/netmap/netmap_mem1.c (contents, props changed)
stable/9/sys/dev/netmap/netmap_mem2.c (contents, props changed)
Added: stable/9/sys/dev/netmap/netmap_mem1.c
==============================================================================
--- /dev/null 00:00:00 1970 (empty, because file is newly added)
+++ stable/9/sys/dev/netmap/netmap_mem1.c Thu May 17 20:04:24 2012 (r235561)
@@ -0,0 +1,521 @@
+/*
+ * Copyright (C) 2011 Matteo Landi, Luigi Rizzo. 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.
+ */
+
+/*
+ * $FreeBSD$
+ *
+ * The original netmap memory allocator, using a single large
+ * chunk of memory allocated with contigmalloc.
+ */
+
+/*
+ * Default amount of memory pre-allocated by the module.
+ * We start with a large size and then shrink our demand
+ * according to what is avalable when the module is loaded.
+ */
+#define NETMAP_MEMORY_SIZE (64 * 1024 * PAGE_SIZE)
+static void * netmap_malloc(size_t size, const char *msg);
+static void netmap_free(void *addr, const char *msg);
+
+#define netmap_if_malloc(len) netmap_malloc(len, "nifp")
+#define netmap_if_free(v) netmap_free((v), "nifp")
+
+#define netmap_ring_malloc(len) netmap_malloc(len, "ring")
+#define netmap_free_rings(na) \
+ netmap_free((na)->tx_rings[0].ring, "shadow rings");
+
+/*
+ * Allocator for a pool of packet buffers. For each buffer we have
+ * one entry in the bitmap to signal the state. Allocation scans
+ * the bitmap, but since this is done only on attach, we are not
+ * too worried about performance
+ * XXX if we need to allocate small blocks, a translation
+ * table is used both for kernel virtual address and physical
+ * addresses.
+ */
+struct netmap_buf_pool {
+ u_int total_buffers; /* total buffers. */
+ u_int free;
+ u_int bufsize;
+ char *base; /* buffer base address */
+ uint32_t *bitmap; /* one bit per buffer, 1 means free */
+};
+struct netmap_buf_pool nm_buf_pool;
+SYSCTL_INT(_dev_netmap, OID_AUTO, total_buffers,
+ CTLFLAG_RD, &nm_buf_pool.total_buffers, 0, "total_buffers");
+SYSCTL_INT(_dev_netmap, OID_AUTO, free_buffers,
+ CTLFLAG_RD, &nm_buf_pool.free, 0, "free_buffers");
+
+
+/*
+ * Allocate n buffers from the ring, and fill the slot.
+ * Buffer 0 is the 'junk' buffer.
+ */
+static void
+netmap_new_bufs(struct netmap_if *nifp __unused,
+ struct netmap_slot *slot, u_int n)
+{
+ struct netmap_buf_pool *p = &nm_buf_pool;
+ uint32_t bi = 0; /* index in the bitmap */
+ uint32_t mask, j, i = 0; /* slot counter */
+
+ if (n > p->free) {
+ D("only %d out of %d buffers available", i, n);
+ return;
+ }
+ /* termination is guaranteed by p->free */
+ while (i < n && p->free > 0) {
+ uint32_t cur = p->bitmap[bi];
+ if (cur == 0) { /* bitmask is fully used */
+ bi++;
+ continue;
+ }
+ /* locate a slot */
+ for (j = 0, mask = 1; (cur & mask) == 0; j++, mask <<= 1) ;
+ p->bitmap[bi] &= ~mask; /* slot in use */
+ p->free--;
+ slot[i].buf_idx = bi*32+j;
+ slot[i].len = p->bufsize;
+ slot[i].flags = NS_BUF_CHANGED;
+ i++;
+ }
+ ND("allocated %d buffers, %d available", n, p->free);
+}
+
+
+static void
+netmap_free_buf(struct netmap_if *nifp __unused, uint32_t i)
+{
+ struct netmap_buf_pool *p = &nm_buf_pool;
+
+ uint32_t pos, mask;
+ if (i >= p->total_buffers) {
+ D("invalid free index %d", i);
+ return;
+ }
+ pos = i / 32;
+ mask = 1 << (i % 32);
+ if (p->bitmap[pos] & mask) {
+ D("slot %d already free", i);
+ return;
+ }
+ p->bitmap[pos] |= mask;
+ p->free++;
+}
+
+
+/* Descriptor of the memory objects handled by our memory allocator. */
+struct netmap_mem_obj {
+ TAILQ_ENTRY(netmap_mem_obj) nmo_next; /* next object in the
+ chain. */
+ int nmo_used; /* flag set on used memory objects. */
+ size_t nmo_size; /* size of the memory area reserved for the
+ object. */
+ void *nmo_data; /* pointer to the memory area. */
+};
+
+/* Wrap our memory objects to make them ``chainable``. */
+TAILQ_HEAD(netmap_mem_obj_h, netmap_mem_obj);
+
+
+/* Descriptor of our custom memory allocator. */
+struct netmap_mem_d {
+ struct mtx nm_mtx; /* lock used to handle the chain of memory
+ objects. */
+ struct netmap_mem_obj_h nm_molist; /* list of memory objects */
+ size_t nm_size; /* total amount of memory used for rings etc. */
+ size_t nm_totalsize; /* total amount of allocated memory
+ (the difference is used for buffers) */
+ size_t nm_buf_start; /* offset of packet buffers.
+ This is page-aligned. */
+ size_t nm_buf_len; /* total memory for buffers */
+ void *nm_buffer; /* pointer to the whole pre-allocated memory
+ area. */
+};
+
+/* Shorthand to compute a netmap interface offset. */
+#define netmap_if_offset(v) \
+ ((char *) (v) - (char *) nm_mem->nm_buffer)
+/* .. and get a physical address given a memory offset */
+#define netmap_ofstophys(o) \
+ (vtophys(nm_mem->nm_buffer) + (o))
+
+
+/*------ netmap memory allocator -------*/
+/*
+ * Request for a chunk of memory.
+ *
+ * Memory objects are arranged into a list, hence we need to walk this
+ * list until we find an object with the needed amount of data free.
+ * This sounds like a completely inefficient implementation, but given
+ * the fact that data allocation is done once, we can handle it
+ * flawlessly.
+ *
+ * Return NULL on failure.
+ */
+static void *
+netmap_malloc(size_t size, __unused const char *msg)
+{
+ struct netmap_mem_obj *mem_obj, *new_mem_obj;
+ void *ret = NULL;
+
+ NMA_LOCK();
+ TAILQ_FOREACH(mem_obj, &nm_mem->nm_molist, nmo_next) {
+ if (mem_obj->nmo_used != 0 || mem_obj->nmo_size < size)
+ continue;
+
+ new_mem_obj = malloc(sizeof(struct netmap_mem_obj), M_NETMAP,
+ M_WAITOK | M_ZERO);
+ TAILQ_INSERT_BEFORE(mem_obj, new_mem_obj, nmo_next);
+
+ new_mem_obj->nmo_used = 1;
+ new_mem_obj->nmo_size = size;
+ new_mem_obj->nmo_data = mem_obj->nmo_data;
+ memset(new_mem_obj->nmo_data, 0, new_mem_obj->nmo_size);
+
+ mem_obj->nmo_size -= size;
+ mem_obj->nmo_data = (char *) mem_obj->nmo_data + size;
+ if (mem_obj->nmo_size == 0) {
+ TAILQ_REMOVE(&nm_mem->nm_molist, mem_obj,
+ nmo_next);
+ free(mem_obj, M_NETMAP);
+ }
+
+ ret = new_mem_obj->nmo_data;
+
+ break;
+ }
+ NMA_UNLOCK();
+ ND("%s: %d bytes at %p", msg, size, ret);
+
+ return (ret);
+}
+
+/*
+ * Return the memory to the allocator.
+ *
+ * While freeing a memory object, we try to merge adjacent chunks in
+ * order to reduce memory fragmentation.
+ */
+static void
+netmap_free(void *addr, const char *msg)
+{
+ size_t size;
+ struct netmap_mem_obj *cur, *prev, *next;
+
+ if (addr == NULL) {
+ D("NULL addr for %s", msg);
+ return;
+ }
+
+ NMA_LOCK();
+ TAILQ_FOREACH(cur, &nm_mem->nm_molist, nmo_next) {
+ if (cur->nmo_data == addr && cur->nmo_used)
+ break;
+ }
+ if (cur == NULL) {
+ NMA_UNLOCK();
+ D("invalid addr %s %p", msg, addr);
+ return;
+ }
+
+ size = cur->nmo_size;
+ cur->nmo_used = 0;
+
+ /* merge current chunk of memory with the previous one,
+ if present. */
+ prev = TAILQ_PREV(cur, netmap_mem_obj_h, nmo_next);
+ if (prev && prev->nmo_used == 0) {
+ TAILQ_REMOVE(&nm_mem->nm_molist, cur, nmo_next);
+ prev->nmo_size += cur->nmo_size;
+ free(cur, M_NETMAP);
+ cur = prev;
+ }
+
+ /* merge with the next one */
+ next = TAILQ_NEXT(cur, nmo_next);
+ if (next && next->nmo_used == 0) {
+ TAILQ_REMOVE(&nm_mem->nm_molist, next, nmo_next);
+ cur->nmo_size += next->nmo_size;
+ free(next, M_NETMAP);
+ }
+ NMA_UNLOCK();
+ ND("freed %s %d bytes at %p", msg, size, addr);
+}
+
+
+/*
+ * Create and return a new ``netmap_if`` object, and possibly also
+ * rings and packet buffors.
+ *
+ * Return NULL on failure.
+ */
+static void *
+netmap_if_new(const char *ifname, struct netmap_adapter *na)
+{
+ struct netmap_if *nifp;
+ struct netmap_ring *ring;
+ struct netmap_kring *kring;
+ char *buff;
+ u_int i, len, ofs, numdesc;
+ u_int nrx = na->num_rx_rings + 1; /* shorthand, include stack queue */
+ u_int ntx = na->num_tx_rings + 1; /* shorthand, include stack queue */
+
+ /*
+ * the descriptor is followed inline by an array of offsets
+ * to the tx and rx rings in the shared memory region.
+ */
+ len = sizeof(struct netmap_if) + (nrx + ntx) * sizeof(ssize_t);
+ nifp = netmap_if_malloc(len);
+ if (nifp == NULL)
+ return (NULL);
+
+ /* initialize base fields */
+ *(int *)(uintptr_t)&nifp->ni_rx_rings = na->num_rx_rings;
+ *(int *)(uintptr_t)&nifp->ni_tx_rings = na->num_tx_rings;
+ strncpy(nifp->ni_name, ifname, IFNAMSIZ);
+
+ (na->refcount)++; /* XXX atomic ? we are under lock */
+ if (na->refcount > 1)
+ goto final;
+
+ /*
+ * First instance. Allocate the netmap rings
+ * (one for each hw queue, one pair for the host).
+ * The rings are contiguous, but have variable size.
+ * The entire block is reachable at
+ * na->tx_rings[0]
+ */
+ len = (ntx + nrx) * sizeof(struct netmap_ring) +
+ (ntx * na->num_tx_desc + nrx * na->num_rx_desc) *
+ sizeof(struct netmap_slot);
+ buff = netmap_ring_malloc(len);
+ if (buff == NULL) {
+ D("failed to allocate %d bytes for %s shadow ring",
+ len, ifname);
+error:
+ (na->refcount)--;
+ netmap_if_free(nifp);
+ return (NULL);
+ }
+ /* Check whether we have enough buffers */
+ len = ntx * na->num_tx_desc + nrx * na->num_rx_desc;
+ NMA_LOCK();
+ if (nm_buf_pool.free < len) {
+ NMA_UNLOCK();
+ netmap_free(buff, "not enough bufs");
+ goto error;
+ }
+ /*
+ * in the kring, store the pointers to the shared rings
+ * and initialize the rings. We are under NMA_LOCK().
+ */
+ ofs = 0;
+ for (i = 0; i < ntx; i++) { /* Transmit rings */
+ kring = &na->tx_rings[i];
+ numdesc = na->num_tx_desc;
+ bzero(kring, sizeof(*kring));
+ kring->na = na;
+
+ ring = kring->ring = (struct netmap_ring *)(buff + ofs);
+ *(ssize_t *)(uintptr_t)&ring->buf_ofs =
+ nm_buf_pool.base - (char *)ring;
+ ND("txring[%d] at %p ofs %d", i, ring, ring->buf_ofs);
+ *(uint32_t *)(uintptr_t)&ring->num_slots =
+ kring->nkr_num_slots = numdesc;
+
+ /*
+ * IMPORTANT:
+ * Always keep one slot empty, so we can detect new
+ * transmissions comparing cur and nr_hwcur (they are
+ * the same only if there are no new transmissions).
+ */
+ ring->avail = kring->nr_hwavail = numdesc - 1;
+ ring->cur = kring->nr_hwcur = 0;
+ *(uint16_t *)(uintptr_t)&ring->nr_buf_size = NETMAP_BUF_SIZE;
+ netmap_new_bufs(nifp, ring->slot, numdesc);
+
+ ofs += sizeof(struct netmap_ring) +
+ numdesc * sizeof(struct netmap_slot);
+ }
+
+ for (i = 0; i < nrx; i++) { /* Receive rings */
+ kring = &na->rx_rings[i];
+ numdesc = na->num_rx_desc;
+ bzero(kring, sizeof(*kring));
+ kring->na = na;
+
+ ring = kring->ring = (struct netmap_ring *)(buff + ofs);
+ *(ssize_t *)(uintptr_t)&ring->buf_ofs =
+ nm_buf_pool.base - (char *)ring;
+ ND("rxring[%d] at %p offset %d", i, ring, ring->buf_ofs);
+ *(uint32_t *)(uintptr_t)&ring->num_slots =
+ kring->nkr_num_slots = numdesc;
+ ring->cur = kring->nr_hwcur = 0;
+ ring->avail = kring->nr_hwavail = 0; /* empty */
+ *(uint16_t *)(uintptr_t)&ring->nr_buf_size = NETMAP_BUF_SIZE;
+ netmap_new_bufs(nifp, ring->slot, numdesc);
+ ofs += sizeof(struct netmap_ring) +
+ numdesc * sizeof(struct netmap_slot);
+ }
+ NMA_UNLOCK();
+ // XXX initialize the selrecord structs.
+
+final:
+ /*
+ * fill the slots for the rx and tx queues. They contain the offset
+ * between the ring and nifp, so the information is usable in
+ * userspace to reach the ring from the nifp.
+ */
+ for (i = 0; i < ntx; i++) {
+ *(ssize_t *)(uintptr_t)&nifp->ring_ofs[i] =
+ (char *)na->tx_rings[i].ring - (char *)nifp;
+ }
+ for (i = 0; i < nrx; i++) {
+ *(ssize_t *)(uintptr_t)&nifp->ring_ofs[i+ntx] =
+ (char *)na->rx_rings[i].ring - (char *)nifp;
+ }
+ return (nifp);
+}
+
+/*
+ * Initialize the memory allocator.
+ *
+ * Create the descriptor for the memory , allocate the pool of memory
+ * and initialize the list of memory objects with a single chunk
+ * containing the whole pre-allocated memory marked as free.
+ *
+ * Start with a large size, then halve as needed if we fail to
+ * allocate the block. While halving, always add one extra page
+ * because buffers 0 and 1 are used for special purposes.
+ * Return 0 on success, errno otherwise.
+ */
+static int
+netmap_memory_init(void)
+{
+ struct netmap_mem_obj *mem_obj;
+ void *buf = NULL;
+ int i, n, sz = NETMAP_MEMORY_SIZE;
+ int extra_sz = 0; // space for rings and two spare buffers
+
+ for (; sz >= 1<<20; sz >>=1) {
+ extra_sz = sz/200;
+ extra_sz = (extra_sz + 2*PAGE_SIZE - 1) & ~(PAGE_SIZE-1);
+ buf = contigmalloc(sz + extra_sz,
+ M_NETMAP,
+ M_WAITOK | M_ZERO,
+ 0, /* low address */
+ -1UL, /* high address */
+ PAGE_SIZE, /* alignment */
+ 0 /* boundary */
+ );
+ if (buf)
+ break;
+ }
+ if (buf == NULL)
+ return (ENOMEM);
+ sz += extra_sz;
+ nm_mem = malloc(sizeof(struct netmap_mem_d), M_NETMAP,
+ M_WAITOK | M_ZERO);
+ mtx_init(&nm_mem->nm_mtx, "netmap memory allocator lock", NULL,
+ MTX_DEF);
+ TAILQ_INIT(&nm_mem->nm_molist);
+ nm_mem->nm_buffer = buf;
+ nm_mem->nm_totalsize = sz;
+
+ /*
+ * A buffer takes 2k, a slot takes 8 bytes + ring overhead,
+ * so the ratio is 200:1. In other words, we can use 1/200 of
+ * the memory for the rings, and the rest for the buffers,
+ * and be sure we never run out.
+ */
+ nm_mem->nm_size = sz/200;
+ nm_mem->nm_buf_start =
+ (nm_mem->nm_size + PAGE_SIZE - 1) & ~(PAGE_SIZE-1);
+ nm_mem->nm_buf_len = sz - nm_mem->nm_buf_start;
+
+ nm_buf_pool.base = nm_mem->nm_buffer;
+ nm_buf_pool.base += nm_mem->nm_buf_start;
+ netmap_buffer_base = nm_buf_pool.base;
+ D("netmap_buffer_base %p (offset %d)",
+ netmap_buffer_base, (int)nm_mem->nm_buf_start);
+ /* number of buffers, they all start as free */
+
+ netmap_total_buffers = nm_buf_pool.total_buffers =
+ nm_mem->nm_buf_len / NETMAP_BUF_SIZE;
+ nm_buf_pool.bufsize = NETMAP_BUF_SIZE;
+
+ D("Have %d MB, use %dKB for rings, %d buffers at %p",
+ (sz >> 20), (int)(nm_mem->nm_size >> 10),
+ nm_buf_pool.total_buffers, nm_buf_pool.base);
+
+ /* allocate and initialize the bitmap. Entry 0 is considered
+ * always busy (used as default when there are no buffers left).
+ */
+ n = (nm_buf_pool.total_buffers + 31) / 32;
+ nm_buf_pool.bitmap = malloc(sizeof(uint32_t) * n, M_NETMAP,
+ M_WAITOK | M_ZERO);
+ nm_buf_pool.bitmap[0] = ~3; /* slot 0 and 1 always busy */
+ for (i = 1; i < n; i++)
+ nm_buf_pool.bitmap[i] = ~0;
+ nm_buf_pool.free = nm_buf_pool.total_buffers - 2;
+
+ mem_obj = malloc(sizeof(struct netmap_mem_obj), M_NETMAP,
+ M_WAITOK | M_ZERO);
+ TAILQ_INSERT_HEAD(&nm_mem->nm_molist, mem_obj, nmo_next);
+ mem_obj->nmo_used = 0;
+ mem_obj->nmo_size = nm_mem->nm_size;
+ mem_obj->nmo_data = nm_mem->nm_buffer;
+
+ return (0);
+}
+
+
+/*
+ * Finalize the memory allocator.
+ *
+ * Free all the memory objects contained inside the list, and deallocate
+ * the pool of memory; finally free the memory allocator descriptor.
+ */
+static void
+netmap_memory_fini(void)
+{
+ struct netmap_mem_obj *mem_obj;
+
+ while (!TAILQ_EMPTY(&nm_mem->nm_molist)) {
+ mem_obj = TAILQ_FIRST(&nm_mem->nm_molist);
+ TAILQ_REMOVE(&nm_mem->nm_molist, mem_obj, nmo_next);
+ if (mem_obj->nmo_used == 1) {
+ printf("netmap: leaked %d bytes at %p\n",
+ (int)mem_obj->nmo_size,
+ mem_obj->nmo_data);
+ }
+ free(mem_obj, M_NETMAP);
+ }
+ contigfree(nm_mem->nm_buffer, nm_mem->nm_totalsize, M_NETMAP);
+ // XXX mutex_destroy(nm_mtx);
+ free(nm_mem, M_NETMAP);
+}
+/*------------- end of memory allocator -----------------*/
Added: stable/9/sys/dev/netmap/netmap_mem2.c
==============================================================================
--- /dev/null 00:00:00 1970 (empty, because file is newly added)
+++ stable/9/sys/dev/netmap/netmap_mem2.c Thu May 17 20:04:24 2012 (r235561)
@@ -0,0 +1,720 @@
+/*
+ * Copyright (C) 2012 Matteo Landi, Luigi Rizzo. 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.
+ */
+
+/*
+ * $FreeBSD$
+ * $Id: netmap_mem2.c 10830 2012-03-22 18:06:01Z luigi $
+ *
+ * New memory allocator for netmap
+ */
+
+/*
+ * The new version allocates three regions:
+ * nm_if_pool for the struct netmap_if
+ * nm_ring_pool for the struct netmap_ring
+ * nm_buf_pool for the packet buffers.
+ *
+ * All regions need to be page-sized as we export them to
+ * userspace through mmap. Only the latter need to be dma-able,
+ * but for convenience use the same type of allocator for all.
+ *
+ * Once mapped, the three regions are exported to userspace
+ * as a contiguous block, starting from nm_if_pool. Each
+ * cluster (and pool) is an integral number of pages.
+ * [ . . . ][ . . . . . .][ . . . . . . . . . .]
+ * nm_if nm_ring nm_buf
+ *
+ * The userspace areas contain offsets of the objects in userspace.
+ * When (at init time) we write these offsets, we find out the index
+ * of the object, and from there locate the offset from the beginning
+ * of the region.
+ *
+ * Allocator for a pool of memory objects of the same size.
+ * The pool is split into smaller clusters, whose size is a
+ * multiple of the page size. The cluster size is chosen
+ * to minimize the waste for a given max cluster size
+ * (we do it by brute force, as we have relatively few object
+ * per cluster).
+ *
+ * To be polite with the cache, objects are aligned to
+ * the cache line, or 64 bytes. Sizes are rounded to multiple of 64.
+ * For each object we have
+ * one entry in the bitmap to signal the state. Allocation scans
+ * the bitmap, but since this is done only on attach, we are not
+ * too worried about performance
+ */
+
+/*
+ * MEMORY SIZES:
+ *
+ * (all the parameters below will become tunables)
+ *
+ * struct netmap_if is variable size but small.
+ * Assuming each NIC has 8+2 rings, (4+1 tx, 4+1 rx) the netmap_if
+ * uses 120 bytes on a 64-bit machine.
+ * We allocate NETMAP_IF_MAX_SIZE (1024) which should work even for
+ * cards with 48 ring pairs.
+ * The total number of 'struct netmap_if' could be slightly larger
+ * that the total number of rings on all interfaces on the system.
+ */
+#define NETMAP_IF_MAX_SIZE 1024
+#define NETMAP_IF_MAX_NUM 512
+
+/*
+ * netmap rings are up to 2..4k descriptors, 8 bytes each,
+ * plus some glue at the beginning (32 bytes).
+ * We set the default ring size to 9 pages (36K) and enable
+ * a few hundreds of them.
+ */
+#define NETMAP_RING_MAX_SIZE (9*PAGE_SIZE)
+#define NETMAP_RING_MAX_NUM 200 /* approx 8MB */
+
+/*
+ * Buffers: the more the better. Buffer size is NETMAP_BUF_SIZE,
+ * 2k or slightly less, aligned to 64 bytes.
+ * A large 10G interface can have 2k*18 = 36k buffers per interface,
+ * or about 72MB of memory. Up to us to use more.
+ */
+#ifndef CONSERVATIVE
+#define NETMAP_BUF_MAX_NUM 100000 /* 200MB */
+#else /* CONSERVATIVE */
+#define NETMAP_BUF_MAX_NUM 20000 /* 40MB */
+#endif
+
+
+struct netmap_obj_pool {
+ char name[16]; /* name of the allocator */
+ u_int objtotal; /* actual total number of objects. */
+ u_int objfree; /* number of free objects. */
+ u_int clustentries; /* actual objects per cluster */
+
+ /* the total memory space is _numclusters*_clustsize */
+ u_int _numclusters; /* how many clusters */
+ u_int _clustsize; /* cluster size */
+ u_int _objsize; /* actual object size */
+
+ u_int _memtotal; /* _numclusters*_clustsize */
+ struct lut_entry *lut; /* virt,phys addresses, objtotal entries */
+ uint32_t *bitmap; /* one bit per buffer, 1 means free */
+};
+
+struct netmap_mem_d {
+ NM_LOCK_T nm_mtx; /* protect the allocator ? */
+ u_int nm_totalsize; /* shorthand */
+
+ /* pointers to the three allocators */
+ struct netmap_obj_pool *nm_if_pool;
+ struct netmap_obj_pool *nm_ring_pool;
+ struct netmap_obj_pool *nm_buf_pool;
+};
+
+struct lut_entry *netmap_buffer_lut; /* exported */
+
+
+/*
+ * Convert a userspace offset to a phisical address.
+ * XXX re-do in a simpler way.
+ *
+ * The idea here is to hide userspace applications the fact that pre-allocated
+ * memory is not contiguous, but fragmented across different clusters and
+ * smaller memory allocators. Consequently, first of all we need to find which
+ * allocator is owning provided offset, then we need to find out the physical
+ * address associated to target page (this is done using the look-up table.
+ */
+static inline vm_paddr_t
+netmap_ofstophys(vm_offset_t offset)
+{
+ const struct netmap_obj_pool *p[] = {
+ nm_mem->nm_if_pool,
+ nm_mem->nm_ring_pool,
+ nm_mem->nm_buf_pool };
+ int i;
+ vm_offset_t o = offset;
+
+
+ for (i = 0; i < 3; offset -= p[i]->_memtotal, i++) {
+ if (offset >= p[i]->_memtotal)
+ continue;
+ // XXX now scan the clusters
+ return p[i]->lut[offset / p[i]->_objsize].paddr +
+ offset % p[i]->_objsize;
+ }
+ D("invalid ofs 0x%x out of 0x%x 0x%x 0x%x", (u_int)o,
+ p[0]->_memtotal, p[0]->_memtotal + p[1]->_memtotal,
+ p[0]->_memtotal + p[1]->_memtotal + p[2]->_memtotal);
+ return 0; // XXX bad address
+}
+
+/*
+ * 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(v) \
+ netmap_obj_offset(nm_mem->nm_if_pool, (v))
+
+#define netmap_ring_offset(v) \
+ (nm_mem->nm_if_pool->_memtotal + \
+ netmap_obj_offset(nm_mem->nm_ring_pool, (v)))
+
+#define netmap_buf_offset(v) \
+ (nm_mem->nm_if_pool->_memtotal + \
+ nm_mem->nm_ring_pool->_memtotal + \
+ netmap_obj_offset(nm_mem->nm_buf_pool, (v)))
+
+
+static void *
+netmap_obj_malloc(struct netmap_obj_pool *p, int len)
+{
+ 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;
+ }
+
+ /* termination is guaranteed by p->free */
+ while (vaddr == NULL) {
+ 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;
+ }
+ ND("%s allocator: allocated object @ [%d][%d]: vaddr %p", i, j, vaddr);
+
+ return vaddr;
+}
+
+
+/*
+ * free by index, not by address
+ */
+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)
+{
+ int i, j, n = p->_memtotal / p->_clustsize;
+
+ 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;
+ }
+ ND("address %p is not contained inside any cluster (%s)",
+ vaddr, p->name);
+}
+
+#define netmap_if_malloc(len) netmap_obj_malloc(nm_mem->nm_if_pool, len)
+#define netmap_if_free(v) netmap_obj_free_va(nm_mem->nm_if_pool, (v))
+#define netmap_ring_malloc(len) netmap_obj_malloc(nm_mem->nm_ring_pool, len)
+#define netmap_buf_malloc() \
+ netmap_obj_malloc(nm_mem->nm_buf_pool, NETMAP_BUF_SIZE)
+
+
+/* Return the index associated to the given packet buffer */
+#define netmap_buf_index(v) \
+ (netmap_obj_offset(nm_mem->nm_buf_pool, (v)) / nm_mem->nm_buf_pool->_objsize)
+
+
+static void
+netmap_new_bufs(struct netmap_if *nifp __unused,
+ struct netmap_slot *slot, u_int n)
+{
+ struct netmap_obj_pool *p = nm_mem->nm_buf_pool;
+ uint32_t i = 0; /* slot counter */
+
+ for (i = 0; i < n; i++) {
+ void *vaddr = netmap_buf_malloc();
+ if (vaddr == NULL) {
+ D("unable to locate empty packet buffer");
+ goto cleanup;
+ }
+
+ slot[i].buf_idx = netmap_buf_index(vaddr);
+ KASSERT(slot[i].buf_idx != 0,
+ ("Assigning buf_idx=0 to just created slot"));
+ slot[i].len = p->_objsize;
+ slot[i].flags = NS_BUF_CHANGED; // XXX GAETANO hack
+ }
+
+ ND("allocated %d buffers, %d available", n, p->objfree);
+ return;
+
+cleanup:
+ for (i--; i >= 0; i--) {
+ netmap_obj_free(nm_mem->nm_buf_pool, slot[i].buf_idx);
+ }
+}
+
+
+static void
+netmap_free_buf(struct netmap_if *nifp, uint32_t i)
+{
+ struct netmap_obj_pool *p = nm_mem->nm_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(nm_mem->nm_buf_pool, i);
+}
+
+
+/*
+ * Free all resources related to an allocator.
+ */
+static void
+netmap_destroy_obj_allocator(struct netmap_obj_pool *p)
+{
+ if (p == NULL)
+ return;
+ if (p->bitmap)
+ free(p->bitmap, M_NETMAP);
+ if (p->lut) {
+ int i;
+ for (i = 0; i < p->objtotal; i += p->clustentries) {
+ if (p->lut[i].vaddr)
+ contigfree(p->lut[i].vaddr, p->_clustsize, M_NETMAP);
+ }
+ bzero(p->lut, sizeof(struct lut_entry) * p->objtotal);
+ free(p->lut, M_NETMAP);
+ }
+ bzero(p, sizeof(*p));
+ free(p, M_NETMAP);
+}
+
+/*
+ * 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.
+ * In the allocator we don't need to store the objsize,
+ * but we do 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.
+ */
+static struct netmap_obj_pool *
+netmap_new_obj_allocator(const char *name, u_int objtotal, u_int objsize)
+{
+ struct netmap_obj_pool *p;
+ int i, n;
+ u_int clustsize; /* the cluster size, multiple of page size */
+ u_int clustentries; /* how many objects per entry */
+
+#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 NULL;
+ }
+ /* 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;
+ }
+ /*
+ * 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;
+ D("objsize %d clustsize %d objects %d",
+ objsize, clustsize, clustentries);
+
+ p = malloc(sizeof(struct netmap_obj_pool), M_NETMAP,
+ M_WAITOK | M_ZERO);
+ if (p == NULL) {
+ D("Unable to create '%s' allocator", name);
+ return NULL;
+ }
+ /*
+ * Allocate and initialize the lookup table.
+ *
+ * The number of clusters is n = ceil(objtotal/clustentries)
+ * objtotal' = n * clustentries
+ */
+ strncpy(p->name, name, sizeof(p->name));
+ p->clustentries = clustentries;
+ p->_clustsize = clustsize;
+ n = (objtotal + clustentries - 1) / clustentries;
+ p->_numclusters = n;
+ p->objtotal = n * clustentries;
+ p->objfree = p->objtotal - 2; /* obj 0 and 1 are reserved */
+ p->_objsize = objsize;
+ p->_memtotal = p->_numclusters * p->_clustsize;
+
+ p->lut = malloc(sizeof(struct lut_entry) * p->objtotal,
+ M_NETMAP, M_WAITOK | M_ZERO);
+ if (p->lut == NULL) {
+ D("Unable to create lookup table for '%s' allocator", name);
+ goto clean;
+ }
+
+ /* Allocate the bitmap */
+ n = (p->objtotal + 31) / 32;
+ p->bitmap = malloc(sizeof(uint32_t) * n, M_NETMAP, M_WAITOK | M_ZERO);
+ if (p->bitmap == NULL) {
+ D("Unable to create bitmap (%d entries) for allocator '%s'", n,
+ name);
+ goto clean;
+ }
+
+ /*
+ * Allocate clusters, init pointers and bitmap
+ */
+ for (i = 0; i < p->objtotal;) {
+ int lim = i + clustentries;
+ char *clust;
+
+ clust = contigmalloc(clustsize, M_NETMAP, M_WAITOK | M_ZERO,
+ 0, -1UL, PAGE_SIZE, 0);
*** DIFF OUTPUT TRUNCATED AT 1000 LINES ***
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