From: Jacob Keller Date: Wed, 3 Sep 2014 08:12:57 +0000 (+0000) Subject: ixgbe: determine vector count inside ixgbe_acquire_msix_vectors X-Git-Tag: v4.14-rc1~6661^2~27^2~4 X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=3bcf344657afefdd468dd9c2b30a009ee7ce7abc;p=platform%2Fkernel%2Flinux-rpi.git ixgbe: determine vector count inside ixgbe_acquire_msix_vectors Our calculated v_budget doesn't matter except if we allocate MSI-X vectors. We shouldn't need to calculate this outside of the function, so don't. Instead, only calculate it once we attempt to acquire MSI-X vectors. This helps collocate all of the MSI-X vector code together. Signed-off-by: Jacob Keller Tested-by: Phil Schmitt Signed-off-by: Jeff Kirsher --- diff --git a/drivers/net/ethernet/intel/ixgbe/ixgbe_lib.c b/drivers/net/ethernet/intel/ixgbe/ixgbe_lib.c index f504faf..39df14f 100644 --- a/drivers/net/ethernet/intel/ixgbe/ixgbe_lib.c +++ b/drivers/net/ethernet/intel/ixgbe/ixgbe_lib.c @@ -696,23 +696,45 @@ static void ixgbe_set_num_queues(struct ixgbe_adapter *adapter) ixgbe_set_rss_queues(adapter); } -static int ixgbe_acquire_msix_vectors(struct ixgbe_adapter *adapter, - int vectors) +/** + * ixgbe_acquire_msix_vectors - acquire MSI-X vectors + * @adapter: board private structure + * + * Attempts to acquire a suitable range of MSI-X vector interrupts. Will + * return a negative error code if unable to acquire MSI-X vectors for any + * reason. + */ +static int ixgbe_acquire_msix_vectors(struct ixgbe_adapter *adapter) { - int i, vector_threshold; + struct ixgbe_hw *hw = &adapter->hw; + int i, vectors, vector_threshold; + + /* We start by asking for one vector per queue pair */ + vectors = max(adapter->num_rx_queues, adapter->num_tx_queues); - /* We'll want at least 2 (vector_threshold): - * 1) TxQ[0] + RxQ[0] handler - * 2) Other (Link Status Change, etc.) + /* It is easy to be greedy for MSI-X vectors. However, it really + * doesn't do much good if we have a lot more vectors than CPUs. We'll + * be somewhat conservative and only ask for (roughly) the same number + * of vectors as there are CPUs. */ - vector_threshold = MIN_MSIX_COUNT; + vectors = min_t(int, vectors, num_online_cpus()); - /* - * The more we get, the more we will assign to Tx/Rx Cleanup - * for the separate queues...where Rx Cleanup >= Tx Cleanup. - * Right now, we simply care about how many we'll get; we'll - * set them up later while requesting irq's. + /* Some vectors are necessary for non-queue interrupts */ + vectors += NON_Q_VECTORS; + + /* Hardware can only support a maximum of hw.mac->max_msix_vectors. + * With features such as RSS and VMDq, we can easily surpass the + * number of Rx and Tx descriptor queues supported by our device. + * Thus, we cap the maximum in the rare cases where the CPU count also + * exceeds our vector limit + */ + vectors = min_t(int, vectors, hw->mac.max_msix_vectors); + + /* We want a minimum of two MSI-X vectors for (1) a TxQ[0] + RxQ[0] + * handler, and (2) an Other (Link Status Change, etc.) handler. */ + vector_threshold = MIN_MSIX_COUNT; + adapter->msix_entries = kcalloc(vectors, sizeof(struct msix_entry), GFP_KERNEL); @@ -1069,32 +1091,10 @@ static void ixgbe_reset_interrupt_capability(struct ixgbe_adapter *adapter) **/ static void ixgbe_set_interrupt_capability(struct ixgbe_adapter *adapter) { - struct ixgbe_hw *hw = &adapter->hw; - int v_budget, err; - - /* - * It's easy to be greedy for MSI-X vectors, but it really - * doesn't do us much good if we have a lot more vectors - * than CPU's. So let's be conservative and only ask for - * (roughly) the same number of vectors as there are CPU's. - * The default is to use pairs of vectors. - */ - v_budget = max(adapter->num_rx_queues, adapter->num_tx_queues); - v_budget = min_t(int, v_budget, num_online_cpus()); - v_budget += NON_Q_VECTORS; - - /* - * At the same time, hardware can only support a maximum of - * hw.mac->max_msix_vectors vectors. With features - * such as RSS and VMDq, we can easily surpass the number of Rx and Tx - * descriptor queues supported by our device. Thus, we cap it off in - * those rare cases where the cpu count also exceeds our vector limit. - */ - v_budget = min_t(int, v_budget, hw->mac.max_msix_vectors); + int err; - /* A failure in MSI-X entry allocation isn't fatal, but it does - * mean we disable MSI-X capabilities of the adapter. */ - if (!ixgbe_acquire_msix_vectors(adapter, v_budget)) + /* We will try to get MSI-X interrupts first */ + if (!ixgbe_acquire_msix_vectors(adapter)) return; /* At this point, we do not have MSI-X capabilities. We need to