From 2628e8af31a0ee4d28304d96a72fdf4d7822508c Mon Sep 17 00:00:00 2001 From: Chris Metcalf Date: Thu, 1 Aug 2013 11:36:42 -0400 Subject: tile: support jumbo frames in the tilegx network driver Signed-off-by: Chris Metcalf Signed-off-by: David S. Miller --- drivers/net/ethernet/tile/tilegx.c | 347 ++++++++++++++++++++----------------- 1 file changed, 188 insertions(+), 159 deletions(-) (limited to 'drivers/net/ethernet/tile/tilegx.c') diff --git a/drivers/net/ethernet/tile/tilegx.c b/drivers/net/ethernet/tile/tilegx.c index 6085571..39c1e9e 100644 --- a/drivers/net/ethernet/tile/tilegx.c +++ b/drivers/net/ethernet/tile/tilegx.c @@ -76,6 +76,9 @@ #define MAX_FRAGS (MAX_SKB_FRAGS + 1) +/* The "kinds" of buffer stacks (small/large/jumbo). */ +#define MAX_KINDS 3 + /* Size of completions data to allocate. * ISSUE: Probably more than needed since we don't use all the channels. */ @@ -141,10 +144,8 @@ struct tile_net_info { /* NAPI flags. */ bool napi_added; bool napi_enabled; - /* Number of small sk_buffs which must still be provided. */ - unsigned int num_needed_small_buffers; - /* Number of large sk_buffs which must still be provided. */ - unsigned int num_needed_large_buffers; + /* Number of buffers (by kind) which must still be provided. */ + unsigned int num_needed_buffers[MAX_KINDS]; /* A timer for handling egress completions. */ struct hrtimer egress_timer; /* True if "egress_timer" is scheduled. */ @@ -200,24 +201,25 @@ static DEFINE_PER_CPU(struct tile_net_info, per_cpu_info); /* The "context" for all devices. */ static gxio_mpipe_context_t context; -/* Buffer sizes and mpipe enum codes for buffer stacks. +/* The buffer size enums for each buffer stack. * See arch/tile/include/gxio/mpipe.h for the set of possible values. + * We avoid the "10384" size because it can induce "false chaining" + * on "cut-through" jumbo packets. */ -#define BUFFER_SIZE_SMALL_ENUM GXIO_MPIPE_BUFFER_SIZE_128 -#define BUFFER_SIZE_SMALL 128 -#define BUFFER_SIZE_LARGE_ENUM GXIO_MPIPE_BUFFER_SIZE_1664 -#define BUFFER_SIZE_LARGE 1664 +static gxio_mpipe_buffer_size_enum_t buffer_size_enums[MAX_KINDS] = { + GXIO_MPIPE_BUFFER_SIZE_128, + GXIO_MPIPE_BUFFER_SIZE_1664, + GXIO_MPIPE_BUFFER_SIZE_16384 +}; -/* The small/large "buffer stacks". */ -static int small_buffer_stack = -1; -static int large_buffer_stack = -1; +/* The actual memory allocated for the buffer stacks. */ +static void *buffer_stack_vas[MAX_KINDS]; -/* Amount of memory allocated for each buffer stack. */ -static size_t buffer_stack_size; +/* The amount of memory allocated for each buffer stack. */ +static size_t buffer_stack_bytes[MAX_KINDS]; -/* The actual memory allocated for the buffer stacks. */ -static void *small_buffer_stack_va; -static void *large_buffer_stack_va; +/* The first buffer stack index (small = +0, large = +1, jumbo = +2). */ +static int first_buffer_stack = -1; /* The buckets. */ static int first_bucket = -1; @@ -238,6 +240,9 @@ static char *loopify_link_name; /* If "tile_net.custom" was specified, this is non-NULL. */ static char *custom_str; +/* If "tile_net.jumbo=NUM" was specified, this is "NUM". */ +static uint jumbo_num; + /* The "tile_net.cpus" argument specifies the cpus that are dedicated * to handle ingress packets. * @@ -292,6 +297,12 @@ MODULE_PARM_DESC(loopify, "name the device to use loop0/1 for ingress/egress"); module_param_named(custom, custom_str, charp, 0444); MODULE_PARM_DESC(custom, "indicates a (heavily) customized classifier"); +/* The "tile_net.jumbo" argument causes us to support "jumbo" packets, + * and to allocate the given number of "jumbo" buffers. + */ +module_param_named(jumbo, jumbo_num, uint, 0444); +MODULE_PARM_DESC(jumbo, "the number of buffers to support jumbo packets"); + /* Atomically update a statistics field. * Note that on TILE-Gx, this operation is fire-and-forget on the * issuing core (single-cycle dispatch) and takes only a few cycles @@ -305,15 +316,15 @@ static void tile_net_stats_add(unsigned long value, unsigned long *field) } /* Allocate and push a buffer. */ -static bool tile_net_provide_buffer(bool small) +static bool tile_net_provide_buffer(int kind) { - int stack = small ? small_buffer_stack : large_buffer_stack; + gxio_mpipe_buffer_size_enum_t bse = buffer_size_enums[kind]; + size_t bs = gxio_mpipe_buffer_size_enum_to_buffer_size(bse); const unsigned long buffer_alignment = 128; struct sk_buff *skb; int len; - len = sizeof(struct sk_buff **) + buffer_alignment; - len += (small ? BUFFER_SIZE_SMALL : BUFFER_SIZE_LARGE); + len = sizeof(struct sk_buff **) + buffer_alignment + bs; skb = dev_alloc_skb(len); if (skb == NULL) return false; @@ -328,7 +339,7 @@ static bool tile_net_provide_buffer(bool small) /* Make sure "skb" and the back-pointer have been flushed. */ wmb(); - gxio_mpipe_push_buffer(&context, stack, + gxio_mpipe_push_buffer(&context, first_buffer_stack + kind, (void *)va_to_tile_io_addr(skb->data)); return true; @@ -369,24 +380,19 @@ static void tile_net_pop_all_buffers(int stack) static void tile_net_provide_needed_buffers(void) { struct tile_net_info *info = &__get_cpu_var(per_cpu_info); - - while (info->num_needed_small_buffers != 0) { - if (!tile_net_provide_buffer(true)) - goto oops; - info->num_needed_small_buffers--; - } - - while (info->num_needed_large_buffers != 0) { - if (!tile_net_provide_buffer(false)) - goto oops; - info->num_needed_large_buffers--; + int kind; + + for (kind = 0; kind < MAX_KINDS; kind++) { + while (info->num_needed_buffers[kind] != 0) { + if (!tile_net_provide_buffer(kind)) { + /* Add info to the allocation failure dump. */ + pr_notice("Tile %d still needs some buffers\n", + info->my_cpu); + return; + } + info->num_needed_buffers[kind]--; + } } - - return; - -oops: - /* Add a description to the page allocation failure dump. */ - pr_notice("Tile %d still needs some buffers\n", info->my_cpu); } static inline bool filter_packet(struct net_device *dev, void *buf) @@ -426,10 +432,12 @@ static void tile_net_receive_skb(struct net_device *dev, struct sk_buff *skb, tile_net_stats_add(len, &priv->stats.rx_bytes); /* Need a new buffer. */ - if (idesc->size == BUFFER_SIZE_SMALL_ENUM) - info->num_needed_small_buffers++; + if (idesc->size == buffer_size_enums[0]) + info->num_needed_buffers[0]++; + else if (idesc->size == buffer_size_enums[1]) + info->num_needed_buffers[1]++; else - info->num_needed_large_buffers++; + info->num_needed_buffers[2]++; } /* Handle a packet. Return true if "processed", false if "filtered". */ @@ -437,29 +445,29 @@ static bool tile_net_handle_packet(gxio_mpipe_idesc_t *idesc) { struct tile_net_info *info = &__get_cpu_var(per_cpu_info); struct net_device *dev = tile_net_devs_for_channel[idesc->channel]; + struct tile_net_priv *priv = netdev_priv(dev); uint8_t l2_offset; void *va; void *buf; unsigned long len; bool filter; - /* Drop packets for which no buffer was available. - * NOTE: This happens under heavy load. + /* Drop packets for which no buffer was available (which can + * happen under heavy load), or for which the me/tr/ce flags + * are set (which can happen for jumbo cut-through packets, + * or with a customized classifier). */ - if (idesc->be) { - struct tile_net_priv *priv = netdev_priv(dev); - tile_net_stats_add(1, &priv->stats.rx_dropped); - gxio_mpipe_iqueue_consume(&info->iqueue, idesc); - if (net_ratelimit()) - pr_info("Dropping packet (insufficient buffers).\n"); - return false; + if (idesc->be || idesc->me || idesc->tr || idesc->ce) { + if (dev) + tile_net_stats_add(1, &priv->stats.rx_errors); + goto drop; } /* Get the "l2_offset", if allowed. */ l2_offset = custom_str ? 0 : gxio_mpipe_idesc_get_l2_offset(idesc); - /* Get the raw buffer VA (includes "headroom"). */ - va = tile_io_addr_to_va((unsigned long)(long)idesc->va); + /* Get the VA (including NET_IP_ALIGN bytes of "headroom"). */ + va = tile_io_addr_to_va((unsigned long)idesc->va); /* Get the actual packet start/length. */ buf = va + l2_offset; @@ -470,6 +478,9 @@ static bool tile_net_handle_packet(gxio_mpipe_idesc_t *idesc) filter = filter_packet(dev, buf); if (filter) { + if (dev) + tile_net_stats_add(1, &priv->stats.rx_dropped); +drop: gxio_mpipe_iqueue_drop(&info->iqueue, idesc); } else { struct sk_buff *skb = mpipe_buf_to_skb(va); @@ -722,86 +733,95 @@ static int tile_net_update(struct net_device *dev) return 0; } -/* Allocate and initialize mpipe buffer stacks, and register them in - * the mPIPE TLBs, for both small and large packet sizes. - * This routine supports tile_net_init_mpipe(), below. - */ -static int init_buffer_stacks(struct net_device *dev, int num_buffers) +/* Initialize a buffer stack. */ +static int create_buffer_stack(struct net_device *dev, + int kind, size_t num_buffers) { pte_t hash_pte = pte_set_home((pte_t) { 0 }, PAGE_HOME_HASH); - int rc; + size_t needed = gxio_mpipe_calc_buffer_stack_bytes(num_buffers); + int stack_idx = first_buffer_stack + kind; + void *va; + int i, rc; - /* Compute stack bytes; we round up to 64KB and then use - * alloc_pages() so we get the required 64KB alignment as well. + /* Round up to 64KB and then use alloc_pages() so we get the + * required 64KB alignment. */ - buffer_stack_size = - ALIGN(gxio_mpipe_calc_buffer_stack_bytes(num_buffers), - 64 * 1024); - - /* Allocate two buffer stack indices. */ - rc = gxio_mpipe_alloc_buffer_stacks(&context, 2, 0, 0); - if (rc < 0) { - netdev_err(dev, "gxio_mpipe_alloc_buffer_stacks failed: %d\n", - rc); - return rc; - } - small_buffer_stack = rc; - large_buffer_stack = rc + 1; + buffer_stack_bytes[kind] = ALIGN(needed, 64 * 1024); - /* Allocate the small memory stack. */ - small_buffer_stack_va = - alloc_pages_exact(buffer_stack_size, GFP_KERNEL); - if (small_buffer_stack_va == NULL) { + va = alloc_pages_exact(buffer_stack_bytes[kind], GFP_KERNEL); + if (va == NULL) { netdev_err(dev, - "Could not alloc %zd bytes for buffer stacks\n", - buffer_stack_size); + "Could not alloc %zd bytes for buffer stack %d\n", + buffer_stack_bytes[kind], kind); return -ENOMEM; } - rc = gxio_mpipe_init_buffer_stack(&context, small_buffer_stack, - BUFFER_SIZE_SMALL_ENUM, - small_buffer_stack_va, - buffer_stack_size, 0); + + /* Initialize the buffer stack. */ + rc = gxio_mpipe_init_buffer_stack(&context, stack_idx, + buffer_size_enums[kind], + va, buffer_stack_bytes[kind], 0); if (rc != 0) { netdev_err(dev, "gxio_mpipe_init_buffer_stack: %d\n", rc); + free_pages_exact(va, buffer_stack_bytes[kind]); return rc; } - rc = gxio_mpipe_register_client_memory(&context, small_buffer_stack, + + buffer_stack_vas[kind] = va; + + rc = gxio_mpipe_register_client_memory(&context, stack_idx, hash_pte, 0); if (rc != 0) { - netdev_err(dev, - "gxio_mpipe_register_buffer_memory failed: %d\n", - rc); + netdev_err(dev, "gxio_mpipe_register_client_memory: %d\n", rc); return rc; } - /* Allocate the large buffer stack. */ - large_buffer_stack_va = - alloc_pages_exact(buffer_stack_size, GFP_KERNEL); - if (large_buffer_stack_va == NULL) { - netdev_err(dev, - "Could not alloc %zd bytes for buffer stacks\n", - buffer_stack_size); - return -ENOMEM; - } - rc = gxio_mpipe_init_buffer_stack(&context, large_buffer_stack, - BUFFER_SIZE_LARGE_ENUM, - large_buffer_stack_va, - buffer_stack_size, 0); - if (rc != 0) { - netdev_err(dev, "gxio_mpipe_init_buffer_stack failed: %d\n", - rc); - return rc; + /* Provide initial buffers. */ + for (i = 0; i < num_buffers; i++) { + if (!tile_net_provide_buffer(kind)) { + netdev_err(dev, "Cannot allocate initial sk_bufs!\n"); + return -ENOMEM; + } } - rc = gxio_mpipe_register_client_memory(&context, large_buffer_stack, - hash_pte, 0); - if (rc != 0) { - netdev_err(dev, - "gxio_mpipe_register_buffer_memory failed: %d\n", - rc); + + return 0; +} + +/* Allocate and initialize mpipe buffer stacks, and register them in + * the mPIPE TLBs, for small, large, and (possibly) jumbo packet sizes. + * This routine supports tile_net_init_mpipe(), below. + */ +static int init_buffer_stacks(struct net_device *dev, + int network_cpus_count) +{ + int num_kinds = MAX_KINDS - (jumbo_num == 0); + size_t num_buffers; + int rc; + + /* Allocate the buffer stacks. */ + rc = gxio_mpipe_alloc_buffer_stacks(&context, num_kinds, 0, 0); + if (rc < 0) { + netdev_err(dev, "gxio_mpipe_alloc_buffer_stacks: %d\n", rc); return rc; } + first_buffer_stack = rc; - return 0; + /* Enough small/large buffers to (normally) avoid buffer errors. */ + num_buffers = + network_cpus_count * (IQUEUE_ENTRIES + TILE_NET_BATCH); + + /* Allocate the small memory stack. */ + if (rc >= 0) + rc = create_buffer_stack(dev, 0, num_buffers); + + /* Allocate the large buffer stack. */ + if (rc >= 0) + rc = create_buffer_stack(dev, 1, num_buffers); + + /* Allocate the jumbo buffer stack if needed. */ + if (rc >= 0 && jumbo_num != 0) + rc = create_buffer_stack(dev, 2, jumbo_num); + + return rc; } /* Allocate per-cpu resources (memory for completions and idescs). @@ -940,13 +960,14 @@ static int tile_net_setup_interrupts(struct net_device *dev) /* Undo any state set up partially by a failed call to tile_net_init_mpipe. */ static void tile_net_init_mpipe_fail(void) { - int cpu; + int kind, cpu; /* Do cleanups that require the mpipe context first. */ - if (small_buffer_stack >= 0) - tile_net_pop_all_buffers(small_buffer_stack); - if (large_buffer_stack >= 0) - tile_net_pop_all_buffers(large_buffer_stack); + for (kind = 0; kind < MAX_KINDS; kind++) { + if (buffer_stack_vas[kind] != NULL) { + tile_net_pop_all_buffers(first_buffer_stack + kind); + } + } /* Destroy mpipe context so the hardware no longer owns any memory. */ gxio_mpipe_destroy(&context); @@ -961,15 +982,15 @@ static void tile_net_init_mpipe_fail(void) info->iqueue.idescs = NULL; } - if (small_buffer_stack_va) - free_pages_exact(small_buffer_stack_va, buffer_stack_size); - if (large_buffer_stack_va) - free_pages_exact(large_buffer_stack_va, buffer_stack_size); + for (kind = 0; kind < MAX_KINDS; kind++) { + if (buffer_stack_vas[kind] != NULL) { + free_pages_exact(buffer_stack_vas[kind], + buffer_stack_bytes[kind]); + buffer_stack_vas[kind] = NULL; + } + } - small_buffer_stack_va = NULL; - large_buffer_stack_va = NULL; - large_buffer_stack = -1; - small_buffer_stack = -1; + first_buffer_stack = -1; first_bucket = -1; } @@ -984,7 +1005,7 @@ static void tile_net_init_mpipe_fail(void) */ static int tile_net_init_mpipe(struct net_device *dev) { - int i, num_buffers, rc; + int rc; int cpu; int first_ring, ring; int network_cpus_count = cpus_weight(network_cpus_map); @@ -1001,27 +1022,10 @@ static int tile_net_init_mpipe(struct net_device *dev) } /* Set up the buffer stacks. */ - num_buffers = - network_cpus_count * (IQUEUE_ENTRIES + TILE_NET_BATCH); - rc = init_buffer_stacks(dev, num_buffers); + rc = init_buffer_stacks(dev, network_cpus_count); if (rc != 0) goto fail; - /* Provide initial buffers. */ - rc = -ENOMEM; - for (i = 0; i < num_buffers; i++) { - if (!tile_net_provide_buffer(true)) { - netdev_err(dev, "Cannot allocate initial sk_bufs!\n"); - goto fail; - } - } - for (i = 0; i < num_buffers; i++) { - if (!tile_net_provide_buffer(false)) { - netdev_err(dev, "Cannot allocate initial sk_bufs!\n"); - goto fail; - } - } - /* Allocate one NotifRing for each network cpu. */ rc = gxio_mpipe_alloc_notif_rings(&context, network_cpus_count, 0, 0); if (rc < 0) { @@ -1063,13 +1067,13 @@ fail: */ static int tile_net_init_egress(struct net_device *dev, int echannel) { + static int ering = -1; struct page *headers_page, *edescs_page, *equeue_page; gxio_mpipe_edesc_t *edescs; gxio_mpipe_equeue_t *equeue; unsigned char *headers; int headers_order, edescs_order, equeue_order; size_t edescs_size; - int edma; int rc = -ENOMEM; /* Only initialize once. */ @@ -1110,25 +1114,37 @@ static int tile_net_init_egress(struct net_device *dev, int echannel) } equeue = pfn_to_kaddr(page_to_pfn(equeue_page)); - /* Allocate an edma ring. Note that in practice this can't - * fail, which is good, because we will leak an edma ring if so. - */ - rc = gxio_mpipe_alloc_edma_rings(&context, 1, 0, 0); - if (rc < 0) { - netdev_warn(dev, "gxio_mpipe_alloc_edma_rings failed: %d\n", - rc); - goto fail_equeue; + /* Allocate an edma ring (using a one entry "free list"). */ + if (ering < 0) { + rc = gxio_mpipe_alloc_edma_rings(&context, 1, 0, 0); + if (rc < 0) { + netdev_warn(dev, "gxio_mpipe_alloc_edma_rings: %d\n", + rc); + goto fail_equeue; + } + ering = rc; } - edma = rc; /* Initialize the equeue. */ - rc = gxio_mpipe_equeue_init(equeue, &context, edma, echannel, + rc = gxio_mpipe_equeue_init(equeue, &context, ering, echannel, edescs, edescs_size, 0); if (rc != 0) { netdev_err(dev, "gxio_mpipe_equeue_init failed: %d\n", rc); goto fail_equeue; } + /* Don't reuse the ering later. */ + ering = -1; + + if (jumbo_num != 0) { + /* Make sure "jumbo" packets can be egressed safely. */ + if (gxio_mpipe_equeue_set_snf_size(equeue, 10368) < 0) { + /* ISSUE: There is no "gxio_mpipe_equeue_destroy()". */ + netdev_warn(dev, "Jumbo packets may not be egressed" + " properly on channel %d\n", echannel); + } + } + /* Done. */ egress_for_echannel[echannel].equeue = equeue; egress_for_echannel[echannel].headers = headers; @@ -1156,6 +1172,17 @@ static int tile_net_link_open(struct net_device *dev, gxio_mpipe_link_t *link, netdev_err(dev, "Failed to open '%s'\n", link_name); return rc; } + if (jumbo_num != 0) { + u32 attr = GXIO_MPIPE_LINK_RECEIVE_JUMBO; + rc = gxio_mpipe_link_set_attr(link, attr, 1); + if (rc != 0) { + netdev_err(dev, + "Cannot receive jumbo packets on '%s'\n", + link_name); + gxio_mpipe_link_close(link); + return rc; + } + } rc = gxio_mpipe_link_channel(link); if (rc < 0 || rc >= TILE_NET_CHANNELS) { netdev_err(dev, "gxio_mpipe_link_channel bad value: %d\n", rc); @@ -1499,8 +1526,8 @@ static void tso_egress(struct net_device *dev, gxio_mpipe_equeue_t *equeue, edesc_head.xfer_size = sh_len; /* This is only used to specify the TLB. */ - edesc_head.stack_idx = large_buffer_stack; - edesc_body.stack_idx = large_buffer_stack; + edesc_head.stack_idx = first_buffer_stack; + edesc_body.stack_idx = first_buffer_stack; /* Egress all the edescs. */ for (segment = 0; segment < sh->gso_segs; segment++) { @@ -1660,7 +1687,7 @@ static int tile_net_tx(struct sk_buff *skb, struct net_device *dev) num_edescs = tile_net_tx_frags(frags, skb, data, skb_headlen(skb)); /* This is only used to specify the TLB. */ - edesc.stack_idx = large_buffer_stack; + edesc.stack_idx = first_buffer_stack; /* Prepare the edescs. */ for (i = 0; i < num_edescs; i++) { @@ -1740,7 +1767,9 @@ static struct net_device_stats *tile_net_get_stats(struct net_device *dev) /* Change the MTU. */ static int tile_net_change_mtu(struct net_device *dev, int new_mtu) { - if ((new_mtu < 68) || (new_mtu > 1500)) + if (new_mtu < 68) + return -EINVAL; + if (new_mtu > ((jumbo_num != 0) ? 9000 : 1500)) return -EINVAL; dev->mtu = new_mtu; return 0; -- cgit v1.1