/*- * 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 #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 Master Zone called the Mbuf * Zone. * * Additionally, FreeBSD provides a Packet Zone, which it * configures as a Secondary Zone to the Mbuf Master Zone, * thus sharing backend Slab kegs with the Mbuf Master 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 Master 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 Master 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 */ 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"); /* * 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, &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, &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, &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, &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, &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); static void *mbuf_jumbo_alloc(uma_zone_t, vm_size_t, uint8_t *, int); /* Ensure that MSIZE is a power of 2. */ CTASSERT((((MSIZE - 1) ^ MSIZE) + 1) >> 1 == 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, #ifdef INVARIANTS trash_init, trash_fini, #else NULL, NULL, #endif MSIZE - 1, 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, #ifdef INVARIANTS trash_dtor, trash_init, trash_fini, #else NULL, NULL, NULL, #endif UMA_ALIGN_PTR, 0); 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, #ifdef INVARIANTS trash_dtor, trash_init, trash_fini, #else NULL, NULL, NULL, #endif UMA_ALIGN_PTR, 0); 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, #ifdef INVARIANTS trash_dtor, trash_init, trash_fini, #else NULL, NULL, NULL, #endif UMA_ALIGN_PTR, 0); uma_zone_set_allocf(zone_jumbo9, mbuf_jumbo_alloc); 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, #ifdef INVARIANTS trash_dtor, trash_init, trash_fini, #else NULL, NULL, NULL, #endif UMA_ALIGN_PTR, 0); uma_zone_set_allocf(zone_jumbo16, mbuf_jumbo_alloc); 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); } SYSINIT(mbuf, SI_SUB_MBUF, SI_ORDER_FIRST, mbuf_init, NULL); /* * UMA backend page allocator for the jumbo frame zones. * * Allocates kernel virtual memory that is backed by contiguous physical * pages. */ static void * mbuf_jumbo_alloc(uma_zone_t zone, vm_size_t bytes, uint8_t *flags, int wait) { /* Inform UMA that this allocator uses kernel_map/object. */ *flags = UMA_SLAB_KERNEL; return ((void *)kmem_alloc_contig(kernel_arena, bytes, wait, (vm_paddr_t)0, ~(vm_paddr_t)0, 1, 0, VM_MEMATTR_DEFAULT)); } /* * Constructor for Mbuf master 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; #ifdef INVARIANTS trash_ctor(mem, size, arg, how); #endif 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 master 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__)); if ((m->m_flags & M_PKTHDR) && !SLIST_EMPTY(&m->m_pkthdr.tags)) m_tag_delete_chain(m, NULL); #ifdef INVARIANTS trash_dtor(mem, size, arg); #endif } /* * 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_nolock(zone_clust)) zone_drain(zone_pack); } /* * 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; #ifdef INVARIANTS trash_ctor(mem, size, arg, how); #endif m = (struct mbuf *)arg; if (m != NULL) { m->m_ext.ext_buf = (caddr_t)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 domain *dp; struct protosw *pr; WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK | WARN_PANIC, NULL, __func__); 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)(); } /* * 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. */ freembuf = (m->m_flags & M_NOFREE) ? 0 : 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); uma_zfree(zone_mbuf, mref); break; case EXT_JUMBOP: uma_zfree(zone_jumbop, m->m_ext.ext_buf); uma_zfree(zone_mbuf, mref); break; case EXT_JUMBO9: uma_zfree(zone_jumbo9, m->m_ext.ext_buf); uma_zfree(zone_mbuf, mref); break; case EXT_JUMBO16: uma_zfree(zone_jumbo16, m->m_ext.ext_buf); uma_zfree(zone_mbuf, mref); break; case EXT_SFBUF: sf_ext_free(m->m_ext.ext_arg1, m->m_ext.ext_arg2); uma_zfree(zone_mbuf, mref); break; case EXT_SFBUF_NOCACHE: sf_ext_free_nocache(m->m_ext.ext_arg1, m->m_ext.ext_arg2); uma_zfree(zone_mbuf, mref); break; case EXT_NET_DRV: case EXT_MOD_TYPE: case EXT_DISPOSABLE: KASSERT(m->m_ext.ext_free != NULL, ("%s: ext_free not set", __func__)); (*(m->m_ext.ext_free))(m, m->m_ext.ext_arg1, m->m_ext.ext_arg2); uma_zfree(zone_mbuf, mref); break; case EXT_EXTREF: KASSERT(m->m_ext.ext_free != NULL, ("%s: ext_free not set", __func__)); (*(m->m_ext.ext_free))(m, m->m_ext.ext_arg1, m->m_ext.ext_arg2); break; default: KASSERT(m->m_ext.ext_type == 0, ("%s: unknown ext_type", __func__)); } } if (freembuf && m != mref) uma_zfree(zone_mbuf, 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)) { zone_drain(zone_pack); 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) { uma_zfree(zone_mbuf, 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) { uma_zfree(zone_mbuf, m); return (NULL); } 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 but still return the top of the newly allocated * chain. */ 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) { if (len > MCLBYTES) mb = m_getjcl(how, type, (flags & M_PKTHDR), MJUMPAGESIZE); else 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) { if (nm != 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, caddr_t buf, u_int size, void (*freef)(struct mbuf *, void *, void *), 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); }