diff options
| -rw-r--r-- | drivers/net/ethernet/ibm/ibmvnic.c | 152 | ||||
| -rw-r--r-- | drivers/net/ethernet/ibm/ibmvnic.h | 45 |
2 files changed, 177 insertions, 20 deletions
diff --git a/drivers/net/ethernet/ibm/ibmvnic.c b/drivers/net/ethernet/ibm/ibmvnic.c index 765a48833b3b..16fd1f1f1228 100644 --- a/drivers/net/ethernet/ibm/ibmvnic.c +++ b/drivers/net/ethernet/ibm/ibmvnic.c @@ -345,6 +345,14 @@ static void free_long_term_buff(struct ibmvnic_adapter *adapter, ltb->map_id = 0; } +/** + * free_ltb_set - free the given set of long term buffers (LTBS) + * @adapter: The ibmvnic adapter containing this ltb set + * @ltb_set: The ltb_set to be freed + * + * Free the set of LTBs in the given set. + */ + static void free_ltb_set(struct ibmvnic_adapter *adapter, struct ibmvnic_ltb_set *ltb_set) { @@ -358,26 +366,117 @@ static void free_ltb_set(struct ibmvnic_adapter *adapter, ltb_set->num_ltbs = 0; } +/** + * alloc_ltb_set() - Allocate a set of long term buffers (LTBs) + * + * @adapter: ibmvnic adapter associated to the LTB + * @ltb_set: container object for the set of LTBs + * @num_buffs: Number of buffers in the LTB + * @buff_size: Size of each buffer in the LTB + * + * Allocate a set of LTBs to accommodate @num_buffs buffers of @buff_size + * each. We currently cap size each LTB to IBMVNIC_ONE_LTB_SIZE. If the + * new set of LTBs have fewer LTBs than the old set, free the excess LTBs. + * If new set needs more than in old set, allocate the remaining ones. + * Try and reuse as many LTBs as possible and avoid reallocation. + * + * Any changes to this allocation strategy must be reflected in + * map_rxpool_buff_to_ltb() and map_txpool_buff_to_ltb(). + */ static int alloc_ltb_set(struct ibmvnic_adapter *adapter, struct ibmvnic_ltb_set *ltb_set, int num_buffs, int buff_size) { - struct ibmvnic_long_term_buff *ltb; - int ltb_size; - int size; + struct device *dev = &adapter->vdev->dev; + struct ibmvnic_ltb_set old_set; + struct ibmvnic_ltb_set new_set; + int rem_size; + int tot_size; /* size of all ltbs */ + int ltb_size; /* size of one ltb */ + int nltbs; + int rc; + int n; + int i; - size = sizeof(struct ibmvnic_long_term_buff); + dev_dbg(dev, "%s() num_buffs %d, buff_size %d\n", __func__, num_buffs, + buff_size); - ltb_set->ltbs = kmalloc(size, GFP_KERNEL); - if (!ltb_set->ltbs) - return -ENOMEM; + ltb_size = rounddown(IBMVNIC_ONE_LTB_SIZE, buff_size); + tot_size = num_buffs * buff_size; + + if (ltb_size > tot_size) + ltb_size = tot_size; + + nltbs = tot_size / ltb_size; + if (tot_size % ltb_size) + nltbs++; + + old_set = *ltb_set; + + if (old_set.num_ltbs == nltbs) { + new_set = old_set; + } else { + int tmp = nltbs * sizeof(struct ibmvnic_long_term_buff); + + new_set.ltbs = kzalloc(tmp, GFP_KERNEL); + if (!new_set.ltbs) + return -ENOMEM; + + new_set.num_ltbs = nltbs; + + /* Free any excess ltbs in old set */ + for (i = new_set.num_ltbs; i < old_set.num_ltbs; i++) + free_long_term_buff(adapter, &old_set.ltbs[i]); + + /* Copy remaining ltbs to new set. All LTBs except the + * last one are of the same size. alloc_long_term_buff() + * will realloc if the size changes. + */ + n = min(old_set.num_ltbs, new_set.num_ltbs); + for (i = 0; i < n; i++) + new_set.ltbs[i] = old_set.ltbs[i]; - ltb_set->num_ltbs = 1; - ltb = <b_set->ltbs[0]; + /* Any additional ltbs in new set will have NULL ltbs for + * now and will be allocated in alloc_long_term_buff(). + */ + + /* We no longer need the old_set so free it. Note that we + * may have reused some ltbs from old set and freed excess + * ltbs above. So we only need to free the container now + * not the LTBs themselves. (i.e. dont free_ltb_set()!) + */ + kfree(old_set.ltbs); + old_set.ltbs = NULL; + old_set.num_ltbs = 0; + + /* Install the new set. If allocations fail below, we will + * retry later and know what size LTBs we need. + */ + *ltb_set = new_set; + } + + i = 0; + rem_size = tot_size; + while (rem_size) { + if (ltb_size > rem_size) + ltb_size = rem_size; + + rem_size -= ltb_size; + + rc = alloc_long_term_buff(adapter, &new_set.ltbs[i], ltb_size); + if (rc) + goto out; + i++; + } - ltb_size = num_buffs * buff_size; + WARN_ON(i != new_set.num_ltbs); - return alloc_long_term_buff(adapter, ltb, ltb_size); + return 0; +out: + /* We may have allocated one/more LTBs before failing and we + * want to try and reuse on next reset. So don't free ltb set. + */ + return rc; } /** @@ -388,14 +487,30 @@ static int alloc_ltb_set(struct ibmvnic_adapter *adapter, * @offset: (Output) offset of buffer in the LTB from @ltbp * * Map the given buffer identified by [rxpool, bufidx] to an LTB in the - * pool and its corresponding offset. + * pool and its corresponding offset. Assume for now that each LTB is of + * different size but could possibly be optimized based on the allocation + * strategy in alloc_ltb_set(). */ static void map_rxpool_buf_to_ltb(struct ibmvnic_rx_pool *rxpool, unsigned int bufidx, struct ibmvnic_long_term_buff **ltbp, unsigned int *offset) { - *ltbp = &rxpool->ltb_set.ltbs[0]; + struct ibmvnic_long_term_buff *ltb; + int nbufs; /* # of buffers in one ltb */ + int i; + + WARN_ON(bufidx >= rxpool->size); + + for (i = 0; i < rxpool->ltb_set.num_ltbs; i++) { + ltb = &rxpool->ltb_set.ltbs[i]; + nbufs = ltb->size / rxpool->buff_size; + if (bufidx < nbufs) + break; + bufidx -= nbufs; + } + + *ltbp = ltb; *offset = bufidx * rxpool->buff_size; } @@ -798,8 +913,9 @@ update_ltb: dev_dbg(dev, "Updating LTB for rx pool %d [%d, %d]\n", i, rx_pool->size, rx_pool->buff_size); - if (alloc_ltb_set(adapter, &rx_pool->ltb_set, - rx_pool->size, rx_pool->buff_size)) + rc = alloc_ltb_set(adapter, &rx_pool->ltb_set, + rx_pool->size, rx_pool->buff_size); + if (rc) goto out; for (j = 0; j < rx_pool->size; ++j) { @@ -4106,16 +4222,16 @@ static void send_request_cap(struct ibmvnic_adapter *adapter, int retry) adapter->desired.rx_entries = adapter->max_rx_add_entries_per_subcrq; - max_entries = IBMVNIC_MAX_LTB_SIZE / + max_entries = IBMVNIC_LTB_SET_SIZE / (adapter->req_mtu + IBMVNIC_BUFFER_HLEN); if ((adapter->req_mtu + IBMVNIC_BUFFER_HLEN) * - adapter->desired.tx_entries > IBMVNIC_MAX_LTB_SIZE) { + adapter->desired.tx_entries > IBMVNIC_LTB_SET_SIZE) { adapter->desired.tx_entries = max_entries; } if ((adapter->req_mtu + IBMVNIC_BUFFER_HLEN) * - adapter->desired.rx_entries > IBMVNIC_MAX_LTB_SIZE) { + adapter->desired.rx_entries > IBMVNIC_LTB_SET_SIZE) { adapter->desired.rx_entries = max_entries; } diff --git a/drivers/net/ethernet/ibm/ibmvnic.h b/drivers/net/ethernet/ibm/ibmvnic.h index 7d430fdf47c0..178035872c32 100644 --- a/drivers/net/ethernet/ibm/ibmvnic.h +++ b/drivers/net/ethernet/ibm/ibmvnic.h @@ -36,9 +36,50 @@ #define IBMVNIC_TSO_BUFS 64 #define IBMVNIC_TSO_POOL_MASK 0x80000000 -#define IBMVNIC_MAX_LTB_SIZE ((1 << (MAX_ORDER - 1)) * PAGE_SIZE) -#define IBMVNIC_BUFFER_HLEN 500 +/* A VNIC adapter has set of Rx and Tx pools (aka queues). Each Rx/Tx pool + * has a set of buffers. The size of each buffer is determined by the MTU. + * + * Each Rx/Tx pool is also associated with a DMA region that is shared + * with the "hardware" (VIOS) and used to send/receive packets. The DMA + * region is also referred to as a Long Term Buffer or LTB. + * + * The size of the DMA region required for an Rx/Tx pool depends on the + * number and size (MTU) of the buffers in the pool. At the max levels + * of 4096 jumbo frames (MTU=9000) we will need about 9K*4K = 36MB plus + * some padding. + * + * But the size of a single DMA region is limited by MAX_ORDER in the + * kernel (about 16MB currently). To support say 4K Jumbo frames, we + * use a set of LTBs (struct ltb_set) per pool. + * + * IBMVNIC_ONE_LTB_MAX - max size of each LTB supported by kernel + * IBMVNIC_ONE_LTB_SIZE - current max size of each LTB in an ltb_set + * (must be <= IBMVNIC_ONE_LTB_MAX) + * IBMVNIC_LTB_SET_SIZE - current size of all LTBs in an ltb_set + * + * Each VNIC can have upto 16 Rx, 16 Tx and 16 TSO pools. The TSO pools + * are of fixed length (IBMVNIC_TSO_BUF_SZ * IBMVNIC_TSO_BUFS) of 4MB. + * + * The Rx and Tx pools can have upto 4096 buffers. The max size of these + * buffers is about 9588 (for jumbo frames, including IBMVNIC_BUFFER_HLEN). + * So, setting the IBMVNIC_LTB_SET_SIZE for a pool to 4096 * 9588 ~= 38MB. + * + * There is a trade-off in setting IBMVNIC_ONE_LTB_SIZE. If it is large, + * the allocation of the LTB can fail when system is low in memory. If + * its too small, we would need several mappings for each of the Rx/ + * Tx/TSO pools but there is a limit of 255 mappings per vnic in the + * VNIC protocol. + * + * So setting IBMVNIC_ONE_LTB_SIZE to 8MB. With IBMVNIC_LTB_SET_SIZE set + * to 38MB, we will need 5 LTBs per Rx and Tx pool and 1 LTB per TSO + * pool for the 4MB. Thus the 16 Rx and Tx queues require 32 * 5 = 160 + * plus 16 for the TSO pools for a total of 176 LTB mappings per VNIC. + */ +#define IBMVNIC_ONE_LTB_MAX ((u32)((1 << (MAX_ORDER - 1)) * PAGE_SIZE)) +#define IBMVNIC_ONE_LTB_SIZE min((u32)(8 << 20), IBMVNIC_ONE_LTB_MAX) +#define IBMVNIC_LTB_SET_SIZE (38 << 20) +#define IBMVNIC_BUFFER_HLEN 500 #define IBMVNIC_RESET_DELAY 100 static const char ibmvnic_priv_flags[][ETH_GSTRING_LEN] = { |