/* * Copyright (C) 2015 Robert Jarzmik * * Scatterlist splitting helpers. * * This source code is licensed under the GNU General Public License, * Version 2. See the file COPYING for more details. */ #include #include struct sg_splitter { struct scatterlist *in_sg0; int nents; off_t skip_sg0; unsigned int length_last_sg; struct scatterlist *out_sg; }; static int sg_calculate_split(struct scatterlist *in, int nents, int nb_splits, off_t skip, const size_t *sizes, struct sg_splitter *splitters, bool mapped) { int i; unsigned int sglen; size_t size = sizes[0], len; struct sg_splitter *curr = splitters; struct scatterlist *sg; for (i = 0; i < nb_splits; i++) { splitters[i].in_sg0 = NULL; splitters[i].nents = 0; } for_each_sg(in, sg, nents, i) { sglen = mapped ? sg_dma_len(sg) : sg->length; if (skip > sglen) { skip -= sglen; continue; } len = min_t(size_t, size, sglen - skip); if (!curr->in_sg0) { curr->in_sg0 = sg; curr->skip_sg0 = skip; } size -= len; curr->nents++; curr->length_last_sg = len; while (!size && (skip + len < sglen) && (--nb_splits > 0)) { curr++; size = *(++sizes); skip += len; len = min_t(size_t, size, sglen - skip); curr->in_sg0 = sg; curr->skip_sg0 = skip; curr->nents = 1; curr->length_last_sg = len; size -= len; } skip = 0; if (!size && --nb_splits > 0) { curr++; size = *(++sizes); } if (!nb_splits) break; } return (size || !splitters[0].in_sg0) ? -EINVAL : 0; } static void sg_split_phys(struct sg_splitter *splitters, const int nb_splits) { int i, j; struct scatterlist *in_sg, *out_sg; struct sg_splitter *split; for (i = 0, split = splitters; i < nb_splits; i++, split++) { in_sg = split->in_sg0; out_sg = split->out_sg; for (j = 0; j < split->nents; j++, out_sg++) { *out_sg = *in_sg; if (!j) { out_sg->offset += split->skip_sg0; out_sg->length -= split->skip_sg0; } else { out_sg->offset = 0; } sg_dma_address(out_sg) = 0; sg_dma_len(out_sg) = 0; in_sg = sg_next(in_sg); } out_sg[-1].length = split->length_last_sg; sg_mark_end(out_sg - 1); } } static void sg_split_mapped(struct sg_splitter *splitters, const int nb_splits) { int i, j; struct scatterlist *in_sg, *out_sg; struct sg_splitter *split; for (i = 0, split = splitters; i < nb_splits; i++, split++) { in_sg = split->in_sg0; out_sg = split->out_sg; for (j = 0; j < split->nents; j++, out_sg++) { sg_dma_address(out_sg) = sg_dma_address(in_sg); sg_dma_len(out_sg) = sg_dma_len(in_sg); if (!j) { sg_dma_address(out_sg) += split->skip_sg0; sg_dma_len(out_sg) -= split->skip_sg0; } in_sg = sg_next(in_sg); } sg_dma_len(--out_sg) = split->length_last_sg; } } /** * sg_split - split a scatterlist into several scatterlists * @in: the input sg list * @in_mapped_nents: the result of a dma_map_sg(in, ...), or 0 if not mapped. * @skip: the number of bytes to skip in the input sg list * @nb_splits: the number of desired sg outputs * @split_sizes: the respective size of each output sg list in bytes * @out: an array where to store the allocated output sg lists * @out_mapped_nents: the resulting sg lists mapped number of sg entries. Might * be NULL if sglist not already mapped (in_mapped_nents = 0) * @gfp_mask: the allocation flag * * This function splits the input sg list into nb_splits sg lists, which are * allocated and stored into out. * The @in is split into : * - @out[0], which covers bytes [@skip .. @skip + @split_sizes[0] - 1] of @in * - @out[1], which covers bytes [@skip + split_sizes[0] .. * @skip + @split_sizes[0] + @split_sizes[1] -1] * etc ... * It will be the caller's duty to kfree() out array members. * * Returns 0 upon success, or error code */ int sg_split(struct scatterlist *in, const int in_mapped_nents, const off_t skip, const int nb_splits, const size_t *split_sizes, struct scatterlist **out, int *out_mapped_nents, gfp_t gfp_mask) { int i, ret; struct sg_splitter *splitters; splitters = kcalloc(nb_splits, sizeof(*splitters), gfp_mask); if (!splitters) return -ENOMEM; ret = sg_calculate_split(in, sg_nents(in), nb_splits, skip, split_sizes, splitters, false); if (ret < 0) goto err; ret = -ENOMEM; for (i = 0; i < nb_splits; i++) { splitters[i].out_sg = kmalloc_array(splitters[i].nents, sizeof(struct scatterlist), gfp_mask); if (!splitters[i].out_sg) goto err; } /* * The order of these 3 calls is important and should be kept. */ sg_split_phys(splitters, nb_splits); ret = sg_calculate_split(in, in_mapped_nents, nb_splits, skip, split_sizes, splitters, true); if (ret < 0) goto err; sg_split_mapped(splitters, nb_splits); for (i = 0; i < nb_splits; i++) { out[i] = splitters[i].out_sg; if (out_mapped_nents) out_mapped_nents[i] = splitters[i].nents; } kfree(splitters); return 0; err: for (i = 0; i < nb_splits; i++) kfree(splitters[i].out_sg); kfree(splitters); return ret; } EXPORT_SYMBOL(sg_split); > parentb05d0cfa1932376dc388a0fe67564572a84374a3 (diff)parent9665b74562ab95bcf1b0684d599bc6779c433fca (diff)
Merge branch 'mlxsw-Reflect-nexthop-status-changes'
Jiri Pirko says: ==================== mlxsw: Reflect nexthop status changes Ido says: When the kernel forwards IPv4 packets via multipath routes it doesn't consider nexthops that are dead or linkdown. For example, if the nexthop netdev is administratively down or doesn't have a carrier. Devices capable of offloading such multipath routes need to be made aware of changes in the reflected nexthops' status. Otherwise, the device might forward packets via non-functional nexthops, resulting in packet loss. This patchset aims to fix that. The first 11 patches deal with the necessary restructuring in the mlxsw driver, so that it's able to correctly add and remove nexthops from the device's adjacency table. The 12th patch adds the NH_{ADD,DEL} events to the FIB notification chain. These notifications are sent whenever the kernel decides to add or remove a nexthop from the forwarding plane. Finally, the last three patches add support for these events in the mlxsw driver, which is currently the only driver capable of offloading multipath routes. ==================== Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'include/net')
-rw-r--r--include/net/ip_fib.h7
1 files changed, 7 insertions, 0 deletions
diff --git a/include/net/ip_fib.h b/include/net/ip_fib.h