/*- * SPDX-License-Identifier: BSD-2-Clause-FreeBSD * * Copyright (c) 2004, 2005, * Bosko Milekic . 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 unmodified, 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 __FBSDID("$FreeBSD$"); #include "opt_param.h" #include "opt_kern_tls.h" #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include /* * In FreeBSD, Mbufs and Mbuf Clusters are allocated from UMA * Zones. * * Mbuf Clusters (2K, contiguous) are allocated from the Cluster * Zone. The Zone can be capped at kern.ipc.nmbclusters, if the * administrator so desires. * * Mbufs are allocated from a UMA Primary Zone called the Mbuf * Zone. * * Additionally, FreeBSD provides a Packet Zone, which it * configures as a Secondary Zone to the Mbuf Primary Zone, * thus sharing backend Slab kegs with the Mbuf Primary Zone. * * Thus common-case allocations and locking are simplified: * * m_clget() m_getcl() * | | * | .------------>[(Packet Cache)] m_get(), m_gethdr() * | | [ Packet ] | * [(Cluster Cache)] [ Secondary ] [ (Mbuf Cache) ] * [ Cluster Zone ] [ Zone ] [ Mbuf Primary Zone ] * | \________ | * [ Cluster Keg ] \ / * | [ Mbuf Keg ] * [ Cluster Slabs ] | * | [ Mbuf Slabs ] * \____________(VM)_________________/ * * * Whenever an object is allocated with uma_zalloc() out of * one of the Zones its _ctor_ function is executed. The same * for any deallocation through uma_zfree() the _dtor_ function * is executed. * * Caches are per-CPU and are filled from the Primary Zone. * * Whenever an object is allocated from the underlying global * memory pool it gets pre-initialized with the _zinit_ functions. * When the Keg's are overfull objects get decommissioned with * _zfini_ functions and free'd back to the global memory pool. * */ int nmbufs; /* limits number of mbufs */ int nmbclusters; /* limits number of mbuf clusters */ int nmbjumbop; /* limits number of page size jumbo clusters */ int nmbjumbo9; /* limits number of 9k jumbo clusters */ int nmbjumbo16; /* limits number of 16k jumbo clusters */ bool mb_use_ext_pgs = true; /* use M_EXTPG mbufs for sendfile & TLS */ SYSCTL_BOOL(_kern_ipc, OID_AUTO, mb_use_ext_pgs, CTLFLAG_RWTUN, &mb_use_ext_pgs, 0, "Use unmapped mbufs for sendfile(2) and TLS offload"); static quad_t maxmbufmem; /* overall real memory limit for all mbufs */ SYSCTL_QUAD(_kern_ipc, OID_AUTO, maxmbufmem, CTLFLAG_RDTUN | CTLFLAG_NOFETCH, &maxmbufmem, 0, "Maximum real memory allocatable to various mbuf types"); static counter_u64_t snd_tag_count; SYSCTL_COUNTER_U64(_kern_ipc, OID_AUTO, num_snd_tags, CTLFLAG_RW, &snd_tag_count, "# of active mbuf send tags"); /* * tunable_mbinit() has to be run before any mbuf allocations are done. */ static void tunable_mbinit(void *dummy) { quad_t realmem; /* * The default limit for all mbuf related memory is 1/2 of all * available kernel memory (physical or kmem). * At most it can be 3/4 of available kernel memory. */ realmem = qmin((quad_t)physmem * PAGE_SIZE, vm_kmem_size); maxmbufmem = realmem / 2; TUNABLE_QUAD_FETCH("kern.ipc.maxmbufmem", &maxmbufmem); if (maxmbufmem > realmem / 4 * 3) maxmbufmem = realmem / 4 * 3; TUNABLE_INT_FETCH("kern.ipc.nmbclusters", &nmbclusters); if (nmbclusters == 0) nmbclusters = maxmbufmem / MCLBYTES / 4; TUNABLE_INT_FETCH("kern.ipc.nmbjumbop", &nmbjumbop); if (nmbjumbop == 0) nmbjumbop = maxmbufmem / MJUMPAGESIZE / 4; TUNABLE_INT_FETCH("kern.ipc.nmbjumbo9", &nmbjumbo9); if (nmbjumbo9 == 0) nmbjumbo9 = maxmbufmem / MJUM9BYTES / 6; TUNABLE_INT_FETCH("kern.ipc.nmbjumbo16", &nmbjumbo16); if (nmbjumbo16 == 0) nmbjumbo16 = maxmbufmem / MJUM16BYTES / 6; /* * We need at least as many mbufs as we have clusters of * the various types added together. */ TUNABLE_INT_FETCH("kern.ipc.nmbufs", &nmbufs); if (nmbufs < nmbclusters + nmbjumbop + nmbjumbo9 + nmbjumbo16) nmbufs = lmax(maxmbufmem / MSIZE / 5, nmbclusters + nmbjumbop + nmbjumbo9 + nmbjumbo16); } SYSINIT(tunable_mbinit, SI_SUB_KMEM, SI_ORDER_MIDDLE, tunable_mbinit, NULL); static int sysctl_nmbclusters(SYSCTL_HANDLER_ARGS) { int error, newnmbclusters; newnmbclusters = nmbclusters; error = sysctl_handle_int(oidp, &newnmbclusters, 0, req); if (error == 0 && req->newptr && newnmbclusters != nmbclusters) { if (newnmbclusters > nmbclusters && nmbufs >= nmbclusters + nmbjumbop + nmbjumbo9 + nmbjumbo16) { nmbclusters = newnmbclusters; nmbclusters = uma_zone_set_max(zone_clust, nmbclusters); EVENTHANDLER_INVOKE(nmbclusters_change); } else error = EINVAL; } return (error); } SYSCTL_PROC(_kern_ipc, OID_AUTO, nmbclusters, CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_NEEDGIANT, &nmbclusters, 0, sysctl_nmbclusters, "IU", "Maximum number of mbuf clusters allowed"); static int sysctl_nmbjumbop(SYSCTL_HANDLER_ARGS) { int error, newnmbjumbop; newnmbjumbop = nmbjumbop; error = sysctl_handle_int(oidp, &newnmbjumbop, 0, req); if (error == 0 && req->newptr && newnmbjumbop != nmbjumbop) { if (newnmbjumbop > nmbjumbop && nmbufs >= nmbclusters + nmbjumbop + nmbjumbo9 + nmbjumbo16) { nmbjumbop = newnmbjumbop; nmbjumbop = uma_zone_set_max(zone_jumbop, nmbjumbop); } else error = EINVAL; } return (error); } SYSCTL_PROC(_kern_ipc, OID_AUTO, nmbjumbop, CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_NEEDGIANT, &nmbjumbop, 0, sysctl_nmbjumbop, "IU", "Maximum number of mbuf page size jumbo clusters allowed"); static int sysctl_nmbjumbo9(SYSCTL_HANDLER_ARGS) { int error, newnmbjumbo9; newnmbjumbo9 = nmbjumbo9; error = sysctl_handle_int(oidp, &newnmbjumbo9, 0, req); if (error == 0 && req->newptr && newnmbjumbo9 != nmbjumbo9) { if (newnmbjumbo9 > nmbjumbo9 && nmbufs >= nmbclusters + nmbjumbop + nmbjumbo9 + nmbjumbo16) { nmbjumbo9 = newnmbjumbo9; nmbjumbo9 = uma_zone_set_max(zone_jumbo9, nmbjumbo9); } else error = EINVAL; } return (error); } SYSCTL_PROC(_kern_ipc, OID_AUTO, nmbjumbo9, CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_NEEDGIANT, &nmbjumbo9, 0, sysctl_nmbjumbo9, "IU", "Maximum number of mbuf 9k jumbo clusters allowed"); static int sysctl_nmbjumbo16(SYSCTL_HANDLER_ARGS) { int error, newnmbjumbo16; newnmbjumbo16 = nmbjumbo16; error = sysctl_handle_int(oidp, &newnmbjumbo16, 0, req); if (error == 0 && req->newptr && newnmbjumbo16 != nmbjumbo16) { if (newnmbjumbo16 > nmbjumbo16 && nmbufs >= nmbclusters + nmbjumbop + nmbjumbo9 + nmbjumbo16) { nmbjumbo16 = newnmbjumbo16; nmbjumbo16 = uma_zone_set_max(zone_jumbo16, nmbjumbo16); } else error = EINVAL; } return (error); } SYSCTL_PROC(_kern_ipc, OID_AUTO, nmbjumbo16, CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_NEEDGIANT, &nmbjumbo16, 0, sysctl_nmbjumbo16, "IU", "Maximum number of mbuf 16k jumbo clusters allowed"); static int sysctl_nmbufs(SYSCTL_HANDLER_ARGS) { int error, newnmbufs; newnmbufs = nmbufs; error = sysctl_handle_int(oidp, &newnmbufs, 0, req); if (error == 0 && req->newptr && newnmbufs != nmbufs) { if (newnmbufs > nmbufs) { nmbufs = newnmbufs; nmbufs = uma_zone_set_max(zone_mbuf, nmbufs); EVENTHANDLER_INVOKE(nmbufs_change); } else error = EINVAL; } return (error); } SYSCTL_PROC(_kern_ipc, OID_AUTO, nmbufs, CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_NEEDGIANT, &nmbufs, 0, sysctl_nmbufs, "IU", "Maximum number of mbufs allowed"); /* * Zones from which we allocate. */ uma_zone_t zone_mbuf; uma_zone_t zone_clust; uma_zone_t zone_pack; uma_zone_t zone_jumbop; uma_zone_t zone_jumbo9; uma_zone_t zone_jumbo16; /* * Local prototypes. */ static int mb_ctor_mbuf(void *, int, void *, int); static int mb_ctor_clust(void *, int, void *, int); static int mb_ctor_pack(void *, int, void *, int); static void mb_dtor_mbuf(void *, int, void *); static void mb_dtor_pack(void *, int, void *); static int mb_zinit_pack(void *, int, int); static void mb_zfini_pack(void *, int); static void mb_reclaim(uma_zone_t, int); /* Ensure that MSIZE is a power of 2. */ CTASSERT((((MSIZE - 1) ^ MSIZE) + 1) >> 1 == MSIZE); _Static_assert(sizeof(struct mbuf) <= MSIZE, "size of mbuf exceeds MSIZE"); /* * Initialize FreeBSD Network buffer allocation. */ static void mbuf_init(void *dummy) { /* * Configure UMA zones for Mbufs, Clusters, and Packets. */ zone_mbuf = uma_zcreate(MBUF_MEM_NAME, MSIZE, mb_ctor_mbuf, mb_dtor_mbuf, NULL, NULL, MSIZE - 1, UMA_ZONE_CONTIG | UMA_ZONE_MAXBUCKET); if (nmbufs > 0) nmbufs = uma_zone_set_max(zone_mbuf, nmbufs); uma_zone_set_warning(zone_mbuf, "kern.ipc.nmbufs limit reached"); uma_zone_set_maxaction(zone_mbuf, mb_reclaim); zone_clust = uma_zcreate(MBUF_CLUSTER_MEM_NAME, MCLBYTES, mb_ctor_clust, NULL, NULL, NULL, UMA_ALIGN_PTR, UMA_ZONE_CONTIG); if (nmbclusters > 0) nmbclusters = uma_zone_set_max(zone_clust, nmbclusters); uma_zone_set_warning(zone_clust, "kern.ipc.nmbclusters limit reached"); uma_zone_set_maxaction(zone_clust, mb_reclaim); zone_pack = uma_zsecond_create(MBUF_PACKET_MEM_NAME, mb_ctor_pack, mb_dtor_pack, mb_zinit_pack, mb_zfini_pack, zone_mbuf); /* Make jumbo frame zone too. Page size, 9k and 16k. */ zone_jumbop = uma_zcreate(MBUF_JUMBOP_MEM_NAME, MJUMPAGESIZE, mb_ctor_clust, NULL, NULL, NULL, UMA_ALIGN_PTR, UMA_ZONE_CONTIG); if (nmbjumbop > 0) nmbjumbop = uma_zone_set_max(zone_jumbop, nmbjumbop); uma_zone_set_warning(zone_jumbop, "kern.ipc.nmbjumbop limit reached"); uma_zone_set_maxaction(zone_jumbop, mb_reclaim); zone_jumbo9 = uma_zcreate(MBUF_JUMBO9_MEM_NAME, MJUM9BYTES, mb_ctor_clust, NULL, NULL, NULL, UMA_ALIGN_PTR, UMA_ZONE_CONTIG); if (nmbjumbo9 > 0) nmbjumbo9 = uma_zone_set_max(zone_jumbo9, nmbjumbo9); uma_zone_set_warning(zone_jumbo9, "kern.ipc.nmbjumbo9 limit reached"); uma_zone_set_maxaction(zone_jumbo9, mb_reclaim); zone_jumbo16 = uma_zcreate(MBUF_JUMBO16_MEM_NAME, MJUM16BYTES, mb_ctor_clust, NULL, NULL, NULL, UMA_ALIGN_PTR, UMA_ZONE_CONTIG); if (nmbjumbo16 > 0) nmbjumbo16 = uma_zone_set_max(zone_jumbo16, nmbjumbo16); uma_zone_set_warning(zone_jumbo16, "kern.ipc.nmbjumbo16 limit reached"); uma_zone_set_maxaction(zone_jumbo16, mb_reclaim); /* * Hook event handler for low-memory situation, used to * drain protocols and push data back to the caches (UMA * later pushes it back to VM). */ EVENTHANDLER_REGISTER(vm_lowmem, mb_reclaim, NULL, EVENTHANDLER_PRI_FIRST); snd_tag_count = counter_u64_alloc(M_WAITOK); } SYSINIT(mbuf, SI_SUB_MBUF, SI_ORDER_FIRST, mbuf_init, NULL); #ifdef DEBUGNET /* * debugnet makes use of a pre-allocated pool of mbufs and clusters. When * debugnet is configured, we initialize a set of UMA cache zones which return * items from this pool. At panic-time, the regular UMA zone pointers are * overwritten with those of the cache zones so that drivers may allocate and * free mbufs and clusters without attempting to allocate physical memory. * * We keep mbufs and clusters in a pair of mbuf queues. In particular, for * the purpose of caching clusters, we treat them as mbufs. */ static struct mbufq dn_mbufq = { STAILQ_HEAD_INITIALIZER(dn_mbufq.mq_head), 0, INT_MAX }; static struct mbufq dn_clustq = { STAILQ_HEAD_INITIALIZER(dn_clustq.mq_head), 0, INT_MAX }; static int dn_clsize; static uma_zone_t dn_zone_mbuf; static uma_zone_t dn_zone_clust; static uma_zone_t dn_zone_pack; static struct debugnet_saved_zones { uma_zone_t dsz_mbuf; uma_zone_t dsz_clust; uma_zone_t dsz_pack; uma_zone_t dsz_jumbop; uma_zone_t dsz_jumbo9; uma_zone_t dsz_jumbo16; bool dsz_debugnet_zones_enabled; } dn_saved_zones; static int dn_buf_import(void *arg, void **store, int count, int domain __unused, int flags) { struct mbufq *q; struct mbuf *m; int i; q = arg; for (i = 0; i < count; i++) { m = mbufq_dequeue(q); if (m == NULL) break; trash_init(m, q == &dn_mbufq ? MSIZE : dn_clsize, flags); store[i] = m; } KASSERT((flags & M_WAITOK) == 0 || i == count, ("%s: ran out of pre-allocated mbufs", __func__)); return (i); } static void dn_buf_release(void *arg, void **store, int count) { struct mbufq *q; struct mbuf *m; int i; q = arg; for (i = 0; i < count; i++) { m = store[i]; (void)mbufq_enqueue(q, m); } } static int dn_pack_import(void *arg __unused, void **store, int count, int domain __unused, int flags __unused) { struct mbuf *m; void *clust; int i; for (i = 0; i < count; i++) { m = m_get(MT_DATA, M_NOWAIT); if (m == NULL) break; clust = uma_zalloc(dn_zone_clust, M_NOWAIT); if (clust == NULL) { m_free(m); break; } mb_ctor_clust(clust, dn_clsize, m, 0); store[i] = m; } KASSERT((flags & M_WAITOK) == 0 || i == count, ("%s: ran out of pre-allocated mbufs", __func__)); return (i); } static void dn_pack_release(void *arg __unused, void **store, int count) { struct mbuf *m; void *clust; int i; for (i = 0; i < count; i++) { m = store[i]; clust = m->m_ext.ext_buf; uma_zfree(dn_zone_clust, clust); uma_zfree(dn_zone_mbuf, m); } } /* * Free the pre-allocated mbufs and clusters reserved for debugnet, and destroy * the corresponding UMA cache zones. */ void debugnet_mbuf_drain(void) { struct mbuf *m; void *item; if (dn_zone_mbuf != NULL) { uma_zdestroy(dn_zone_mbuf); dn_zone_mbuf = NULL; } if (dn_zone_clust != NULL) { uma_zdestroy(dn_zone_clust); dn_zone_clust = NULL; } if (dn_zone_pack != NULL) { uma_zdestroy(dn_zone_pack); dn_zone_pack = NULL; } while ((m = mbufq_dequeue(&dn_mbufq)) != NULL) m_free(m); while ((item = mbufq_dequeue(&dn_clustq)) != NULL) uma_zfree(m_getzone(dn_clsize), item); } /* * Callback invoked immediately prior to starting a debugnet connection. */ void debugnet_mbuf_start(void) { MPASS(!dn_saved_zones.dsz_debugnet_zones_enabled); /* Save the old zone pointers to restore when debugnet is closed. */ dn_saved_zones = (struct debugnet_saved_zones) { .dsz_debugnet_zones_enabled = true, .dsz_mbuf = zone_mbuf, .dsz_clust = zone_clust, .dsz_pack = zone_pack, .dsz_jumbop = zone_jumbop, .dsz_jumbo9 = zone_jumbo9, .dsz_jumbo16 = zone_jumbo16, }; /* * All cluster zones return buffers of the size requested by the * drivers. It's up to the driver to reinitialize the zones if the * MTU of a debugnet-enabled interface changes. */ printf("debugnet: overwriting mbuf zone pointers\n"); zone_mbuf = dn_zone_mbuf; zone_clust = dn_zone_clust; zone_pack = dn_zone_pack; zone_jumbop = dn_zone_clust; zone_jumbo9 = dn_zone_clust; zone_jumbo16 = dn_zone_clust; } /* * Callback invoked when a debugnet connection is closed/finished. */ void debugnet_mbuf_finish(void) { MPASS(dn_saved_zones.dsz_debugnet_zones_enabled); printf("debugnet: restoring mbuf zone pointers\n"); zone_mbuf = dn_saved_zones.dsz_mbuf; zone_clust = dn_saved_zones.dsz_clust; zone_pack = dn_saved_zones.dsz_pack; zone_jumbop = dn_saved_zones.dsz_jumbop; zone_jumbo9 = dn_saved_zones.dsz_jumbo9; zone_jumbo16 = dn_saved_zones.dsz_jumbo16; memset(&dn_saved_zones, 0, sizeof(dn_saved_zones)); } /* * Reinitialize the debugnet mbuf+cluster pool and cache zones. */ void debugnet_mbuf_reinit(int nmbuf, int nclust, int clsize) { struct mbuf *m; void *item; debugnet_mbuf_drain(); dn_clsize = clsize; dn_zone_mbuf = uma_zcache_create("debugnet_" MBUF_MEM_NAME, MSIZE, mb_ctor_mbuf, mb_dtor_mbuf, NULL, NULL, dn_buf_import, dn_buf_release, &dn_mbufq, UMA_ZONE_NOBUCKET); dn_zone_clust = uma_zcache_create("debugnet_" MBUF_CLUSTER_MEM_NAME, clsize, mb_ctor_clust, NULL, NULL, NULL, dn_buf_import, dn_buf_release, &dn_clustq, UMA_ZONE_NOBUCKET); dn_zone_pack = uma_zcache_create("debugnet_" MBUF_PACKET_MEM_NAME, MCLBYTES, mb_ctor_pack, mb_dtor_pack, NULL, NULL, dn_pack_import, dn_pack_release, NULL, UMA_ZONE_NOBUCKET); while (nmbuf-- > 0) { m = m_get(MT_DATA, M_WAITOK); uma_zfree(dn_zone_mbuf, m); } while (nclust-- > 0) { item = uma_zalloc(m_getzone(dn_clsize), M_WAITOK); uma_zfree(dn_zone_clust, item); } } #endif /* DEBUGNET */ /* * Constructor for Mbuf primary zone. * * The 'arg' pointer points to a mb_args structure which * contains call-specific information required to support the * mbuf allocation API. See mbuf.h. */ static int mb_ctor_mbuf(void *mem, int size, void *arg, int how) { struct mbuf *m; struct mb_args *args; int error; int flags; short type; args = (struct mb_args *)arg; type = args->type; /* * The mbuf is initialized later. The caller has the * responsibility to set up any MAC labels too. */ if (type == MT_NOINIT) return (0); m = (struct mbuf *)mem; flags = args->flags; MPASS((flags & M_NOFREE) == 0); error = m_init(m, how, type, flags); return (error); } /* * The Mbuf primary zone destructor. */ static void mb_dtor_mbuf(void *mem, int size, void *arg) { struct mbuf *m; unsigned long flags; m = (struct mbuf *)mem; flags = (unsigned long)arg; KASSERT((m->m_flags & M_NOFREE) == 0, ("%s: M_NOFREE set", __func__)); KASSERT((flags & 0x1) == 0, ("%s: obsolete MB_DTOR_SKIP passed", __func__)); if ((m->m_flags & M_PKTHDR) && !SLIST_EMPTY(&m->m_pkthdr.tags)) m_tag_delete_chain(m, NULL); } /* * The Mbuf Packet zone destructor. */ static void mb_dtor_pack(void *mem, int size, void *arg) { struct mbuf *m; m = (struct mbuf *)mem; if ((m->m_flags & M_PKTHDR) != 0) m_tag_delete_chain(m, NULL); /* Make sure we've got a clean cluster back. */ KASSERT((m->m_flags & M_EXT) == M_EXT, ("%s: M_EXT not set", __func__)); KASSERT(m->m_ext.ext_buf != NULL, ("%s: ext_buf == NULL", __func__)); KASSERT(m->m_ext.ext_free == NULL, ("%s: ext_free != NULL", __func__)); KASSERT(m->m_ext.ext_arg1 == NULL, ("%s: ext_arg1 != NULL", __func__)); KASSERT(m->m_ext.ext_arg2 == NULL, ("%s: ext_arg2 != NULL", __func__)); KASSERT(m->m_ext.ext_size == MCLBYTES, ("%s: ext_size != MCLBYTES", __func__)); KASSERT(m->m_ext.ext_type == EXT_PACKET, ("%s: ext_type != EXT_PACKET", __func__)); #ifdef INVARIANTS trash_dtor(m->m_ext.ext_buf, MCLBYTES, arg); #endif /* * If there are processes blocked on zone_clust, waiting for pages * to be freed up, cause them to be woken up by draining the * packet zone. We are exposed to a race here (in the check for * the UMA_ZFLAG_FULL) where we might miss the flag set, but that * is deliberate. We don't want to acquire the zone lock for every * mbuf free. */ if (uma_zone_exhausted(zone_clust)) uma_zone_reclaim(zone_pack, UMA_RECLAIM_DRAIN); } /* * The Cluster and Jumbo[PAGESIZE|9|16] zone constructor. * * Here the 'arg' pointer points to the Mbuf which we * are configuring cluster storage for. If 'arg' is * empty we allocate just the cluster without setting * the mbuf to it. See mbuf.h. */ static int mb_ctor_clust(void *mem, int size, void *arg, int how) { struct mbuf *m; m = (struct mbuf *)arg; if (m != NULL) { m->m_ext.ext_buf = (char *)mem; m->m_data = m->m_ext.ext_buf; m->m_flags |= M_EXT; m->m_ext.ext_free = NULL; m->m_ext.ext_arg1 = NULL; m->m_ext.ext_arg2 = NULL; m->m_ext.ext_size = size; m->m_ext.ext_type = m_gettype(size); m->m_ext.ext_flags = EXT_FLAG_EMBREF; m->m_ext.ext_count = 1; } return (0); } /* * The Packet secondary zone's init routine, executed on the * object's transition from mbuf keg slab to zone cache. */ static int mb_zinit_pack(void *mem, int size, int how) { struct mbuf *m; m = (struct mbuf *)mem; /* m is virgin. */ if (uma_zalloc_arg(zone_clust, m, how) == NULL || m->m_ext.ext_buf == NULL) return (ENOMEM); m->m_ext.ext_type = EXT_PACKET; /* Override. */ #ifdef INVARIANTS trash_init(m->m_ext.ext_buf, MCLBYTES, how); #endif return (0); } /* * The Packet secondary zone's fini routine, executed on the * object's transition from zone cache to keg slab. */ static void mb_zfini_pack(void *mem, int size) { struct mbuf *m; m = (struct mbuf *)mem; #ifdef INVARIANTS trash_fini(m->m_ext.ext_buf, MCLBYTES); #endif uma_zfree_arg(zone_clust, m->m_ext.ext_buf, NULL); #ifdef INVARIANTS trash_dtor(mem, size, NULL); #endif } /* * The "packet" keg constructor. */ static int mb_ctor_pack(void *mem, int size, void *arg, int how) { struct mbuf *m; struct mb_args *args; int error, flags; short type; m = (struct mbuf *)mem; args = (struct mb_args *)arg; flags = args->flags; type = args->type; MPASS((flags & M_NOFREE) == 0); #ifdef INVARIANTS trash_ctor(m->m_ext.ext_buf, MCLBYTES, arg, how); #endif error = m_init(m, how, type, flags); /* m_ext is already initialized. */ m->m_data = m->m_ext.ext_buf; m->m_flags = (flags | M_EXT); return (error); } /* * This is the protocol drain routine. Called by UMA whenever any of the * mbuf zones is closed to its limit. * * No locks should be held when this is called. The drain routines have to * presently acquire some locks which raises the possibility of lock order * reversal. */ static void mb_reclaim(uma_zone_t zone __unused, int pending __unused) { struct epoch_tracker et; struct domain *dp; struct protosw *pr; WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK | WARN_PANIC, NULL, __func__); NET_EPOCH_ENTER(et); for (dp = domains; dp != NULL; dp = dp->dom_next) for (pr = dp->dom_protosw; pr < dp->dom_protoswNPROTOSW; pr++) if (pr->pr_drain != NULL) (*pr->pr_drain)(); NET_EPOCH_EXIT(et); } /* * Free "count" units of I/O from an mbuf chain. They could be held * in M_EXTPG or just as a normal mbuf. This code is intended to be * called in an error path (I/O error, closed connection, etc). */ void mb_free_notready(struct mbuf *m, int count) { int i; for (i = 0; i < count && m != NULL; i++) { if ((m->m_flags & M_EXTPG) != 0) { m->m_epg_nrdy--; if (m->m_epg_nrdy != 0) continue; } m = m_free(m); } KASSERT(i == count, ("Removed only %d items from %p", i, m)); } /* * Compress an unmapped mbuf into a simple mbuf when it holds a small * amount of data. This is used as a DOS defense to avoid having * small packets tie up wired pages, an ext_pgs structure, and an * mbuf. Since this converts the existing mbuf in place, it can only * be used if there are no other references to 'm'. */ int mb_unmapped_compress(struct mbuf *m) { volatile u_int *refcnt; char buf[MLEN]; /* * Assert that 'm' does not have a packet header. If 'm' had * a packet header, it would only be able to hold MHLEN bytes * and m_data would have to be initialized differently. */ KASSERT((m->m_flags & M_PKTHDR) == 0 && (m->m_flags & M_EXTPG), ("%s: m %p !M_EXTPG or M_PKTHDR", __func__, m)); KASSERT(m->m_len <= MLEN, ("m_len too large %p", m)); if (m->m_ext.ext_flags & EXT_FLAG_EMBREF) { refcnt = &m->m_ext.ext_count; } else { KASSERT(m->m_ext.ext_cnt != NULL, ("%s: no refcounting pointer on %p", __func__, m)); refcnt = m->m_ext.ext_cnt; } if (*refcnt != 1) return (EBUSY); m_copydata(m, 0, m->m_len, buf); /* Free the backing pages. */ m->m_ext.ext_free(m); /* Turn 'm' into a "normal" mbuf. */ m->m_flags &= ~(M_EXT | M_RDONLY | M_EXTPG); m->m_data = m->m_dat; /* Copy data back into m. */ bcopy(buf, mtod(m, char *), m->m_len); return (0); } /* * These next few routines are used to permit downgrading an unmapped * mbuf to a chain of mapped mbufs. This is used when an interface * doesn't supported unmapped mbufs or if checksums need to be * computed in software. * * Each unmapped mbuf is converted to a chain of mbufs. First, any * TLS header data is stored in a regular mbuf. Second, each page of * unmapped data is stored in an mbuf with an EXT_SFBUF external * cluster. These mbufs use an sf_buf to provide a valid KVA for the * associated physical page. They also hold a reference on the * original M_EXTPG mbuf to ensure the physical page doesn't go away. * Finally, any TLS trailer data is stored in a regular mbuf. * * mb_unmapped_free_mext() is the ext_free handler for the EXT_SFBUF * mbufs. It frees the associated sf_buf and releases its reference * on the original M_EXTPG mbuf. * * _mb_unmapped_to_ext() is a helper function that converts a single * unmapped mbuf into a chain of mbufs. * * mb_unmapped_to_ext() is the public function that walks an mbuf * chain converting any unmapped mbufs to mapped mbufs. It returns * the new chain of unmapped mbufs on success. On failure it frees * the original mbuf chain and returns NULL. */ static void mb_unmapped_free_mext(struct mbuf *m) { struct sf_buf *sf; struct mbuf *old_m; sf = m->m_ext.ext_arg1; sf_buf_free(sf); /* Drop the reference on the backing M_EXTPG mbuf. */ old_m = m->m_ext.ext_arg2; mb_free_extpg(old_m); } static struct mbuf * _mb_unmapped_to_ext(struct mbuf *m) { struct mbuf *m_new, *top, *prev, *mref; struct sf_buf *sf; vm_page_t pg; int i, len, off, pglen, pgoff, seglen, segoff; volatile u_int *refcnt; u_int ref_inc = 0; M_ASSERTEXTPG(m); len = m->m_len; KASSERT(m->m_epg_tls == NULL, ("%s: can't convert TLS mbuf %p", __func__, m)); /* See if this is the mbuf that holds the embedded refcount. */ if (m->m_ext.ext_flags & EXT_FLAG_EMBREF) { refcnt = &m->m_ext.ext_count; mref = m; } else { KASSERT(m->m_ext.ext_cnt != NULL, ("%s: no refcounting pointer on %p", __func__, m)); refcnt = m->m_ext.ext_cnt; mref = __containerof(refcnt, struct mbuf, m_ext.ext_count); } /* Skip over any data removed from the front. */ off = mtod(m, vm_offset_t); top = NULL; if (m->m_epg_hdrlen != 0) { if (off >= m->m_epg_hdrlen) { off -= m->m_epg_hdrlen; } else { seglen = m->m_epg_hdrlen - off; segoff = off; seglen = min(seglen, len); off = 0; len -= seglen; m_new = m_get(M_NOWAIT, MT_DATA); if (m_new == NULL) goto fail; m_new->m_len = seglen; prev = top = m_new; memcpy(mtod(m_new, void *), &m->m_epg_hdr[segoff], seglen); } } pgoff = m->m_epg_1st_off; for (i = 0; i < m->m_epg_npgs && len > 0; i++) { pglen = m_epg_pagelen(m, i, pgoff); if (off >= pglen) { off -= pglen; pgoff = 0; continue; } seglen = pglen - off; segoff = pgoff + off; off = 0; seglen = min(seglen, len); len -= seglen; pg = PHYS_TO_VM_PAGE(m->m_epg_pa[i]); m_new = m_get(M_NOWAIT, MT_DATA); if (m_new == NULL) goto fail; if (top == NULL) { top = prev = m_new; } else { prev->m_next = m_new; prev = m_new; } sf = sf_buf_alloc(pg, SFB_NOWAIT); if (sf == NULL) goto fail; ref_inc++; m_extadd(m_new, (char *)sf_buf_kva(sf), PAGE_SIZE, mb_unmapped_free_mext, sf, mref, M_RDONLY, EXT_SFBUF); m_new->m_data += segoff; m_new->m_len = seglen; pgoff = 0; }; if (len != 0) { KASSERT((off + len) <= m->m_epg_trllen, ("off + len > trail (%d + %d > %d)", off, len, m->m_epg_trllen)); m_new = m_get(M_NOWAIT, MT_DATA); if (m_new == NULL) goto fail; if (top == NULL) top = m_new; else prev->m_next = m_new; m_new->m_len = len; memcpy(mtod(m_new, void *), &m->m_epg_trail[off], len); } if (ref_inc != 0) { /* * Obtain an additional reference on the old mbuf for * each created EXT_SFBUF mbuf. They will be dropped * in mb_unmapped_free_mext(). */ if (*refcnt == 1) *refcnt += ref_inc; else atomic_add_int(refcnt, ref_inc); } m_free(m); return (top); fail: if (ref_inc != 0) { /* * Obtain an additional reference on the old mbuf for * each created EXT_SFBUF mbuf. They will be * immediately dropped when these mbufs are freed * below. */ if (*refcnt == 1) *refcnt += ref_inc; else atomic_add_int(refcnt, ref_inc); } m_free(m); m_freem(top); return (NULL); } struct mbuf * mb_unmapped_to_ext(struct mbuf *top) { struct mbuf *m, *next, *prev = NULL; prev = NULL; for (m = top; m != NULL; m = next) { /* m might be freed, so cache the next pointer. */ next = m->m_next; if (m->m_flags & M_EXTPG) { if (prev != NULL) { /* * Remove 'm' from the new chain so * that the 'top' chain terminates * before 'm' in case 'top' is freed * due to an error. */ prev->m_next = NULL; } m = _mb_unmapped_to_ext(m); if (m == NULL) { m_freem(top); m_freem(next); return (NULL); } if (prev == NULL) { top = m; } else { prev->m_next = m; } /* * Replaced one mbuf with a chain, so we must * find the end of chain. */ prev = m_last(m); } else { if (prev != NULL) { prev->m_next = m; } prev = m; } } return (top); } /* * Allocate an empty M_EXTPG mbuf. The ext_free routine is * responsible for freeing any pages backing this mbuf when it is * freed. */ struct mbuf * mb_alloc_ext_pgs(int how, m_ext_free_t ext_free) { struct mbuf *m; m = m_get(how, MT_DATA); if (m == NULL) return (NULL); m->m_epg_npgs = 0; m->m_epg_nrdy = 0; m->m_epg_1st_off = 0; m->m_epg_last_len = 0; m->m_epg_flags = 0; m->m_epg_hdrlen = 0; m->m_epg_trllen = 0; m->m_epg_tls = NULL; m->m_epg_so = NULL; m->m_data = NULL; m->m_flags |= (M_EXT | M_RDONLY | M_EXTPG); m->m_ext.ext_flags = EXT_FLAG_EMBREF; m->m_ext.ext_count = 1; m->m_ext.ext_size = 0; m->m_ext.ext_free = ext_free; return (m); } /* * Clean up after mbufs with M_EXT storage attached to them if the * reference count hits 1. */ void mb_free_ext(struct mbuf *m) { volatile u_int *refcnt; struct mbuf *mref; int freembuf; KASSERT(m->m_flags & M_EXT, ("%s: M_EXT not set on %p", __func__, m)); /* See if this is the mbuf that holds the embedded refcount. */ if (m->m_ext.ext_flags & EXT_FLAG_EMBREF) { refcnt = &m->m_ext.ext_count; mref = m; } else { KASSERT(m->m_ext.ext_cnt != NULL, ("%s: no refcounting pointer on %p", __func__, m)); refcnt = m->m_ext.ext_cnt; mref = __containerof(refcnt, struct mbuf, m_ext.ext_count); } /* * Check if the header is embedded in the cluster. It is * important that we can't touch any of the mbuf fields * after we have freed the external storage, since mbuf * could have been embedded in it. For now, the mbufs * embedded into the cluster are always of type EXT_EXTREF, * and for this type we won't free the mref. */ if (m->m_flags & M_NOFREE) { freembuf = 0; KASSERT(m->m_ext.ext_type == EXT_EXTREF || m->m_ext.ext_type == EXT_RXRING, ("%s: no-free mbuf %p has wrong type", __func__, m)); } else freembuf = 1; /* Free attached storage if this mbuf is the only reference to it. */ if (*refcnt == 1 || atomic_fetchadd_int(refcnt, -1) == 1) { switch (m->m_ext.ext_type) { case EXT_PACKET: /* The packet zone is special. */ if (*refcnt == 0) *refcnt = 1; uma_zfree(zone_pack, mref); break; case EXT_CLUSTER: uma_zfree(zone_clust, m->m_ext.ext_buf); m_free_raw(mref); break; case EXT_JUMBOP: uma_zfree(zone_jumbop, m->m_ext.ext_buf); m_free_raw(mref); break; case EXT_JUMBO9: uma_zfree(zone_jumbo9, m->m_ext.ext_buf); m_free_raw(mref); break; case EXT_JUMBO16: uma_zfree(zone_jumbo16, m->m_ext.ext_buf); m_free_raw(mref); break; case EXT_SFBUF: case EXT_NET_DRV: case EXT_MOD_TYPE: case EXT_DISPOSABLE: KASSERT(mref->m_ext.ext_free != NULL, ("%s: ext_free not set", __func__)); mref->m_ext.ext_free(mref); m_free_raw(mref); break; case EXT_EXTREF: KASSERT(m->m_ext.ext_free != NULL, ("%s: ext_free not set", __func__)); m->m_ext.ext_free(m); break; case EXT_RXRING: KASSERT(m->m_ext.ext_free == NULL, ("%s: ext_free is set", __func__)); break; default: KASSERT(m->m_ext.ext_type == 0, ("%s: unknown ext_type", __func__)); } } if (freembuf && m != mref) m_free_raw(m); } /* * Clean up after mbufs with M_EXTPG storage attached to them if the * reference count hits 1. */ void mb_free_extpg(struct mbuf *m) { volatile u_int *refcnt; struct mbuf *mref; M_ASSERTEXTPG(m); /* See if this is the mbuf that holds the embedded refcount. */ if (m->m_ext.ext_flags & EXT_FLAG_EMBREF) { refcnt = &m->m_ext.ext_count; mref = m; } else { KASSERT(m->m_ext.ext_cnt != NULL, ("%s: no refcounting pointer on %p", __func__, m)); refcnt = m->m_ext.ext_cnt; mref = __containerof(refcnt, struct mbuf, m_ext.ext_count); } /* Free attached storage if this mbuf is the only reference to it. */ if (*refcnt == 1 || atomic_fetchadd_int(refcnt, -1) == 1) { KASSERT(mref->m_ext.ext_free != NULL, ("%s: ext_free not set", __func__)); mref->m_ext.ext_free(mref); #ifdef KERN_TLS if (mref->m_epg_tls != NULL && !refcount_release_if_not_last(&mref->m_epg_tls->refcount)) ktls_enqueue_to_free(mref); else #endif m_free_raw(mref); } if (m != mref) m_free_raw(m); } /* * Official mbuf(9) allocation KPI for stack and drivers: * * m_get() - a single mbuf without any attachments, sys/mbuf.h. * m_gethdr() - a single mbuf initialized as M_PKTHDR, sys/mbuf.h. * m_getcl() - an mbuf + 2k cluster, sys/mbuf.h. * m_clget() - attach cluster to already allocated mbuf. * m_cljget() - attach jumbo cluster to already allocated mbuf. * m_get2() - allocate minimum mbuf that would fit size argument. * m_getm2() - allocate a chain of mbufs/clusters. * m_extadd() - attach external cluster to mbuf. * * m_free() - free single mbuf with its tags and ext, sys/mbuf.h. * m_freem() - free chain of mbufs. */ int m_clget(struct mbuf *m, int how) { KASSERT((m->m_flags & M_EXT) == 0, ("%s: mbuf %p has M_EXT", __func__, m)); m->m_ext.ext_buf = (char *)NULL; uma_zalloc_arg(zone_clust, m, how); /* * On a cluster allocation failure, drain the packet zone and retry, * we might be able to loosen a few clusters up on the drain. */ if ((how & M_NOWAIT) && (m->m_ext.ext_buf == NULL)) { uma_zone_reclaim(zone_pack, UMA_RECLAIM_DRAIN); uma_zalloc_arg(zone_clust, m, how); } MBUF_PROBE2(m__clget, m, how); return (m->m_flags & M_EXT); } /* * m_cljget() is different from m_clget() as it can allocate clusters without * attaching them to an mbuf. In that case the return value is the pointer * to the cluster of the requested size. If an mbuf was specified, it gets * the cluster attached to it and the return value can be safely ignored. * For size it takes MCLBYTES, MJUMPAGESIZE, MJUM9BYTES, MJUM16BYTES. */ void * m_cljget(struct mbuf *m, int how, int size) { uma_zone_t zone; void *retval; if (m != NULL) { KASSERT((m->m_flags & M_EXT) == 0, ("%s: mbuf %p has M_EXT", __func__, m)); m->m_ext.ext_buf = NULL; } zone = m_getzone(size); retval = uma_zalloc_arg(zone, m, how); MBUF_PROBE4(m__cljget, m, how, size, retval); return (retval); } /* * m_get2() allocates minimum mbuf that would fit "size" argument. */ struct mbuf * m_get2(int size, int how, short type, int flags) { struct mb_args args; struct mbuf *m, *n; args.flags = flags; args.type = type; if (size <= MHLEN || (size <= MLEN && (flags & M_PKTHDR) == 0)) return (uma_zalloc_arg(zone_mbuf, &args, how)); if (size <= MCLBYTES) return (uma_zalloc_arg(zone_pack, &args, how)); if (size > MJUMPAGESIZE) return (NULL); m = uma_zalloc_arg(zone_mbuf, &args, how); if (m == NULL) return (NULL); n = uma_zalloc_arg(zone_jumbop, m, how); if (n == NULL) { m_free_raw(m); return (NULL); } return (m); } /* * m_getjcl() returns an mbuf with a cluster of the specified size attached. * For size it takes MCLBYTES, MJUMPAGESIZE, MJUM9BYTES, MJUM16BYTES. */ struct mbuf * m_getjcl(int how, short type, int flags, int size) { struct mb_args args; struct mbuf *m, *n; uma_zone_t zone; if (size == MCLBYTES) return m_getcl(how, type, flags); args.flags = flags; args.type = type; m = uma_zalloc_arg(zone_mbuf, &args, how); if (m == NULL) return (NULL); zone = m_getzone(size); n = uma_zalloc_arg(zone, m, how); if (n == NULL) { m_free_raw(m); return (NULL); } MBUF_PROBE5(m__getjcl, how, type, flags, size, m); return (m); } /* * Allocate a given length worth of mbufs and/or clusters (whatever fits * best) and return a pointer to the top of the allocated chain. If an * existing mbuf chain is provided, then we will append the new chain * to the existing one and return a pointer to the provided mbuf. */ struct mbuf * m_getm2(struct mbuf *m, int len, int how, short type, int flags) { struct mbuf *mb, *nm = NULL, *mtail = NULL; KASSERT(len >= 0, ("%s: len is < 0", __func__)); /* Validate flags. */ flags &= (M_PKTHDR | M_EOR); /* Packet header mbuf must be first in chain. */ if ((flags & M_PKTHDR) && m != NULL) flags &= ~M_PKTHDR; /* Loop and append maximum sized mbufs to the chain tail. */ while (len > 0) { mb = NULL; if (len > MCLBYTES) { mb = m_getjcl(M_NOWAIT, type, (flags & M_PKTHDR), MJUMPAGESIZE); } if (mb == NULL) { if (len >= MINCLSIZE) mb = m_getcl(how, type, (flags & M_PKTHDR)); else if (flags & M_PKTHDR) mb = m_gethdr(how, type); else mb = m_get(how, type); /* * Fail the whole operation if one mbuf can't be * allocated. */ if (mb == NULL) { m_freem(nm); return (NULL); } } /* Book keeping. */ len -= M_SIZE(mb); if (mtail != NULL) mtail->m_next = mb; else nm = mb; mtail = mb; flags &= ~M_PKTHDR; /* Only valid on the first mbuf. */ } if (flags & M_EOR) mtail->m_flags |= M_EOR; /* Only valid on the last mbuf. */ /* If mbuf was supplied, append new chain to the end of it. */ if (m != NULL) { for (mtail = m; mtail->m_next != NULL; mtail = mtail->m_next) ; mtail->m_next = nm; mtail->m_flags &= ~M_EOR; } else m = nm; return (m); } /*- * Configure a provided mbuf to refer to the provided external storage * buffer and setup a reference count for said buffer. * * Arguments: * mb The existing mbuf to which to attach the provided buffer. * buf The address of the provided external storage buffer. * size The size of the provided buffer. * freef A pointer to a routine that is responsible for freeing the * provided external storage buffer. * args A pointer to an argument structure (of any type) to be passed * to the provided freef routine (may be NULL). * flags Any other flags to be passed to the provided mbuf. * type The type that the external storage buffer should be * labeled with. * * Returns: * Nothing. */ void m_extadd(struct mbuf *mb, char *buf, u_int size, m_ext_free_t freef, void *arg1, void *arg2, int flags, int type) { KASSERT(type != EXT_CLUSTER, ("%s: EXT_CLUSTER not allowed", __func__)); mb->m_flags |= (M_EXT | flags); mb->m_ext.ext_buf = buf; mb->m_data = mb->m_ext.ext_buf; mb->m_ext.ext_size = size; mb->m_ext.ext_free = freef; mb->m_ext.ext_arg1 = arg1; mb->m_ext.ext_arg2 = arg2; mb->m_ext.ext_type = type; if (type != EXT_EXTREF) { mb->m_ext.ext_count = 1; mb->m_ext.ext_flags = EXT_FLAG_EMBREF; } else mb->m_ext.ext_flags = 0; } /* * Free an entire chain of mbufs and associated external buffers, if * applicable. */ void m_freem(struct mbuf *mb) { MBUF_PROBE1(m__freem, mb); while (mb != NULL) mb = m_free(mb); } /* * Temporary primitive to allow freeing without going through m_free. */ void m_free_raw(struct mbuf *mb) { uma_zfree(zone_mbuf, mb); } int m_snd_tag_alloc(struct ifnet *ifp, union if_snd_tag_alloc_params *params, struct m_snd_tag **mstp) { if (ifp->if_snd_tag_alloc == NULL) return (EOPNOTSUPP); return (ifp->if_snd_tag_alloc(ifp, params, mstp)); } void m_snd_tag_init(struct m_snd_tag *mst, struct ifnet *ifp, u_int type) { if_ref(ifp); mst->ifp = ifp; refcount_init(&mst->refcount, 1); mst->type = type; counter_u64_add(snd_tag_count, 1); } void m_snd_tag_destroy(struct m_snd_tag *mst) { struct ifnet *ifp; ifp = mst->ifp; ifp->if_snd_tag_free(mst); if_rele(ifp); counter_u64_add(snd_tag_count, -1); } /* * Allocate an mbuf with anonymous external pages. */ struct mbuf * mb_alloc_ext_plus_pages(int len, int how) { struct mbuf *m; vm_page_t pg; int i, npgs; m = mb_alloc_ext_pgs(how, mb_free_mext_pgs); if (m == NULL) return (NULL); m->m_epg_flags |= EPG_FLAG_ANON; npgs = howmany(len, PAGE_SIZE); for (i = 0; i < npgs; i++) { do { pg = vm_page_alloc(NULL, 0, VM_ALLOC_NORMAL | VM_ALLOC_NOOBJ | VM_ALLOC_NODUMP | VM_ALLOC_WIRED); if (pg == NULL) { if (how == M_NOWAIT) { m->m_epg_npgs = i; m_free(m); return (NULL); } vm_wait(NULL); } } while (pg == NULL); m->m_epg_pa[i] = VM_PAGE_TO_PHYS(pg); } m->m_epg_npgs = npgs; return (m); } /* * Copy the data in the mbuf chain to a chain of mbufs with anonymous external * unmapped pages. * len is the length of data in the input mbuf chain. * mlen is the maximum number of bytes put into each ext_page mbuf. */ struct mbuf * mb_mapped_to_unmapped(struct mbuf *mp, int len, int mlen, int how, struct mbuf **mlast) { struct mbuf *m, *mout; char *pgpos, *mbpos; int i, mblen, mbufsiz, pglen, xfer; if (len == 0) return (NULL); mbufsiz = min(mlen, len); m = mout = mb_alloc_ext_plus_pages(mbufsiz, how); if (m == NULL) return (m); pgpos = (char *)(void *)PHYS_TO_DMAP(m->m_epg_pa[0]); pglen = PAGE_SIZE; mblen = 0; i = 0; do { if (pglen == 0) { if (++i == m->m_epg_npgs) { m->m_epg_last_len = PAGE_SIZE; mbufsiz = min(mlen, len); m->m_next = mb_alloc_ext_plus_pages(mbufsiz, how); m = m->m_next; if (m == NULL) { m_freem(mout); return (m); } i = 0; } pgpos = (char *)(void *)PHYS_TO_DMAP(m->m_epg_pa[i]); pglen = PAGE_SIZE; } while (mblen == 0) { if (mp == NULL) { m_freem(mout); return (NULL); } KASSERT((mp->m_flags & M_EXTPG) == 0, ("mb_copym_ext_pgs: ext_pgs input mbuf")); mbpos = mtod(mp, char *); mblen = mp->m_len; mp = mp->m_next; } xfer = min(mblen, pglen); memcpy(pgpos, mbpos, xfer); pgpos += xfer; mbpos += xfer; pglen -= xfer; mblen -= xfer; len -= xfer; m->m_len += xfer; } while (len > 0); m->m_epg_last_len = PAGE_SIZE - pglen; if (mlast != NULL) *mlast = m; return (mout); }