diff options
Diffstat (limited to 'drivers/ntb')
| -rw-r--r-- | drivers/ntb/ntb_transport.c | 169 |
1 files changed, 168 insertions, 1 deletions
diff --git a/drivers/ntb/ntb_transport.c b/drivers/ntb/ntb_transport.c index 99033228dccb..40c90ca10729 100644 --- a/drivers/ntb/ntb_transport.c +++ b/drivers/ntb/ntb_transport.c @@ -93,6 +93,12 @@ static bool use_dma; module_param(use_dma, bool, 0644); MODULE_PARM_DESC(use_dma, "Use DMA engine to perform large data copy"); +static bool use_msi; +#ifdef CONFIG_NTB_MSI +module_param(use_msi, bool, 0644); +MODULE_PARM_DESC(use_msi, "Use MSI interrupts instead of doorbells"); +#endif + static struct dentry *nt_debugfs_dir; /* Only two-ports NTB devices are supported */ @@ -188,6 +194,11 @@ struct ntb_transport_qp { u64 tx_err_no_buf; u64 tx_memcpy; u64 tx_async; + + bool use_msi; + int msi_irq; + struct ntb_msi_desc msi_desc; + struct ntb_msi_desc peer_msi_desc; }; struct ntb_transport_mw { @@ -221,6 +232,10 @@ struct ntb_transport_ctx { u64 qp_bitmap; u64 qp_bitmap_free; + bool use_msi; + unsigned int msi_spad_offset; + u64 msi_db_mask; + bool link_is_up; struct delayed_work link_work; struct work_struct link_cleanup; @@ -667,6 +682,114 @@ static int ntb_transport_setup_qp_mw(struct ntb_transport_ctx *nt, return 0; } +static irqreturn_t ntb_transport_isr(int irq, void *dev) +{ + struct ntb_transport_qp *qp = dev; + + tasklet_schedule(&qp->rxc_db_work); + + return IRQ_HANDLED; +} + +static void ntb_transport_setup_qp_peer_msi(struct ntb_transport_ctx *nt, + unsigned int qp_num) +{ + struct ntb_transport_qp *qp = &nt->qp_vec[qp_num]; + int spad = qp_num * 2 + nt->msi_spad_offset; + + if (!nt->use_msi) + return; + + if (spad >= ntb_spad_count(nt->ndev)) + return; + + qp->peer_msi_desc.addr_offset = + ntb_peer_spad_read(qp->ndev, PIDX, spad); + qp->peer_msi_desc.data = + ntb_peer_spad_read(qp->ndev, PIDX, spad + 1); + + dev_dbg(&qp->ndev->pdev->dev, "QP%d Peer MSI addr=%x data=%x\n", + qp_num, qp->peer_msi_desc.addr_offset, qp->peer_msi_desc.data); + + if (qp->peer_msi_desc.addr_offset) { + qp->use_msi = true; + dev_info(&qp->ndev->pdev->dev, + "Using MSI interrupts for QP%d\n", qp_num); + } +} + +static void ntb_transport_setup_qp_msi(struct ntb_transport_ctx *nt, + unsigned int qp_num) +{ + struct ntb_transport_qp *qp = &nt->qp_vec[qp_num]; + int spad = qp_num * 2 + nt->msi_spad_offset; + int rc; + + if (!nt->use_msi) + return; + + if (spad >= ntb_spad_count(nt->ndev)) { + dev_warn_once(&qp->ndev->pdev->dev, + "Not enough SPADS to use MSI interrupts\n"); + return; + } + + ntb_spad_write(qp->ndev, spad, 0); + ntb_spad_write(qp->ndev, spad + 1, 0); + + if (!qp->msi_irq) { + qp->msi_irq = ntbm_msi_request_irq(qp->ndev, ntb_transport_isr, + KBUILD_MODNAME, qp, + &qp->msi_desc); + if (qp->msi_irq < 0) { + dev_warn(&qp->ndev->pdev->dev, + "Unable to allocate MSI interrupt for qp%d\n", + qp_num); + return; + } + } + + rc = ntb_spad_write(qp->ndev, spad, qp->msi_desc.addr_offset); + if (rc) + goto err_free_interrupt; + + rc = ntb_spad_write(qp->ndev, spad + 1, qp->msi_desc.data); + if (rc) + goto err_free_interrupt; + + dev_dbg(&qp->ndev->pdev->dev, "QP%d MSI %d addr=%x data=%x\n", + qp_num, qp->msi_irq, qp->msi_desc.addr_offset, + qp->msi_desc.data); + + return; + +err_free_interrupt: + devm_free_irq(&nt->ndev->dev, qp->msi_irq, qp); +} + +static void ntb_transport_msi_peer_desc_changed(struct ntb_transport_ctx *nt) +{ + int i; + + dev_dbg(&nt->ndev->pdev->dev, "Peer MSI descriptors changed"); + + for (i = 0; i < nt->qp_count; i++) + ntb_transport_setup_qp_peer_msi(nt, i); +} + +static void ntb_transport_msi_desc_changed(void *data) +{ + struct ntb_transport_ctx *nt = data; + int i; + + dev_dbg(&nt->ndev->pdev->dev, "MSI descriptors changed"); + + for (i = 0; i < nt->qp_count; i++) + ntb_transport_setup_qp_msi(nt, i); + + ntb_peer_db_set(nt->ndev, nt->msi_db_mask); +} + static void ntb_free_mw(struct ntb_transport_ctx *nt, int num_mw) { struct ntb_transport_mw *mw = &nt->mw_vec[num_mw]; @@ -905,6 +1028,20 @@ static void ntb_transport_link_work(struct work_struct *work) int rc = 0, i, spad; /* send the local info, in the opposite order of the way we read it */ + + if (nt->use_msi) { + rc = ntb_msi_setup_mws(ndev); + if (rc) { + dev_warn(&pdev->dev, + "Failed to register MSI memory window: %d\n", + rc); + nt->use_msi = false; + } + } + + for (i = 0; i < nt->qp_count; i++) + ntb_transport_setup_qp_msi(nt, i); + for (i = 0; i < nt->mw_count; i++) { size = nt->mw_vec[i].phys_size; @@ -962,6 +1099,7 @@ static void ntb_transport_link_work(struct work_struct *work) struct ntb_transport_qp *qp = &nt->qp_vec[i]; ntb_transport_setup_qp_mw(nt, i); + ntb_transport_setup_qp_peer_msi(nt, i); if (qp->client_ready) schedule_delayed_work(&qp->link_work, 0); @@ -1135,6 +1273,19 @@ static int ntb_transport_probe(struct ntb_client *self, struct ntb_dev *ndev) return -ENOMEM; nt->ndev = ndev; + + /* + * If we are using MSI, and have at least one extra memory window, + * we will reserve the last MW for the MSI window. + */ + if (use_msi && mw_count > 1) { + rc = ntb_msi_init(ndev, ntb_transport_msi_desc_changed); + if (!rc) { + mw_count -= 1; + nt->use_msi = true; + } + } + spad_count = ntb_spad_count(ndev); /* Limit the MW's based on the availability of scratchpads */ @@ -1148,6 +1299,8 @@ static int ntb_transport_probe(struct ntb_client *self, struct ntb_dev *ndev) max_mw_count_for_spads = (spad_count - MW0_SZ_HIGH) / 2; nt->mw_count = min(mw_count, max_mw_count_for_spads); + nt->msi_spad_offset = nt->mw_count * 2 + MW0_SZ_HIGH; + nt->mw_vec = kcalloc_node(mw_count, sizeof(*nt->mw_vec), GFP_KERNEL, node); if (!nt->mw_vec) { @@ -1178,6 +1331,12 @@ static int ntb_transport_probe(struct ntb_client *self, struct ntb_dev *ndev) qp_bitmap = ntb_db_valid_mask(ndev); qp_count = ilog2(qp_bitmap); + if (nt->use_msi) { + qp_count -= 1; + nt->msi_db_mask = 1 << qp_count; + ntb_db_clear_mask(ndev, nt->msi_db_mask); + } + if (max_num_clients && max_num_clients < qp_count) qp_count = max_num_clients; else if (nt->mw_count < qp_count) @@ -1601,7 +1760,10 @@ static void ntb_tx_copy_callback(void *data, iowrite32(entry->flags | DESC_DONE_FLAG, &hdr->flags); - ntb_peer_db_set(qp->ndev, BIT_ULL(qp->qp_num)); + if (qp->use_msi) + ntb_msi_peer_trigger(qp->ndev, PIDX, &qp->peer_msi_desc); + else + ntb_peer_db_set(qp->ndev, BIT_ULL(qp->qp_num)); /* The entry length can only be zero if the packet is intended to be a * "link down" or similar. Since no payload is being sent in these @@ -2269,6 +2431,11 @@ static void ntb_transport_doorbell_callback(void *data, int vector) u64 db_bits; unsigned int qp_num; + if (ntb_db_read(nt->ndev) & nt->msi_db_mask) { + ntb_transport_msi_peer_desc_changed(nt); + ntb_db_clear(nt->ndev, nt->msi_db_mask); + } + db_bits = (nt->qp_bitmap & ~nt->qp_bitmap_free & ntb_db_vector_mask(nt->ndev, vector)); |