From 0bc3827f8c9f74b5335667d70309cefa12ec14ae Mon Sep 17 00:00:00 2001 From: Jakub Kicinski Date: Sun, 19 Feb 2017 11:58:14 -0800 Subject: [PATCH] nfp: allow application firmware to limit number of SR-IOV VFs Some application firmware projects may choose to limit the number of VFs available below what is specified in PCI capability to be able to reuse the PCIe interface resources. There may also be projects which use cases don't require SR-IOV support at all and therefore don't want to spend time implementing/testing it. Check nfd_vf_cfg_max_vfs firmware symbol to see if application firmware is reporting how many VFs it supports. This mechanism is an opt-in, if symbol is not present we will only look at the PCI capability values. Signed-off-by: Jakub Kicinski Signed-off-by: David S. Miller --- drivers/net/ethernet/netronome/nfp/nfp_main.c | 25 +++++++++++++++++++++++++ drivers/net/ethernet/netronome/nfp/nfp_main.h | 2 ++ 2 files changed, 27 insertions(+) diff --git a/drivers/net/ethernet/netronome/nfp/nfp_main.c b/drivers/net/ethernet/netronome/nfp/nfp_main.c index 8cda6b0..dedac72 100644 --- a/drivers/net/ethernet/netronome/nfp/nfp_main.c +++ b/drivers/net/ethernet/netronome/nfp/nfp_main.c @@ -47,6 +47,7 @@ #include "nfpcore/nfp.h" #include "nfpcore/nfp_cpp.h" +#include "nfpcore/nfp_nffw.h" #include "nfpcore/nfp_nsp_eth.h" #include "nfpcore/nfp6000_pcie.h" @@ -70,12 +71,34 @@ static const struct pci_device_id nfp_pci_device_ids[] = { }; MODULE_DEVICE_TABLE(pci, nfp_pci_device_ids); +static void nfp_pcie_sriov_read_nfd_limit(struct nfp_pf *pf) +{ +#ifdef CONFIG_PCI_IOV + int err; + + pf->limit_vfs = nfp_rtsym_read_le(pf->cpp, "nfd_vf_cfg_max_vfs", &err); + if (!err) + return; + + pf->limit_vfs = ~0; + /* Allow any setting for backwards compatibility if symbol not found */ + if (err != -ENOENT) + nfp_warn(pf->cpp, "Warning: VF limit read failed: %d\n", err); +#endif +} + static int nfp_pcie_sriov_enable(struct pci_dev *pdev, int num_vfs) { #ifdef CONFIG_PCI_IOV struct nfp_pf *pf = pci_get_drvdata(pdev); int err; + if (num_vfs > pf->limit_vfs) { + nfp_info(pf->cpp, "Firmware limits number of VFs to %u\n", + pf->limit_vfs); + return -EINVAL; + } + err = pci_enable_sriov(pdev, num_vfs); if (err) { dev_warn(&pdev->dev, "Failed to enable PCI sriov: %d\n", err); @@ -333,6 +356,8 @@ static int nfp_pci_probe(struct pci_dev *pdev, if (err) goto err_cpp_free; + nfp_pcie_sriov_read_nfd_limit(pf); + err = nfp_net_pci_probe(pf); if (err) goto err_fw_unload; diff --git a/drivers/net/ethernet/netronome/nfp/nfp_main.h b/drivers/net/ethernet/netronome/nfp/nfp_main.h index 6c40fa3..39105d0 100644 --- a/drivers/net/ethernet/netronome/nfp/nfp_main.h +++ b/drivers/net/ethernet/netronome/nfp/nfp_main.h @@ -59,6 +59,7 @@ struct nfp_eth_table; * @tx_area: Pointer to the CPP area for the TX queues * @rx_area: Pointer to the CPP area for the FL/RX queues * @irq_entries: Array of MSI-X entries for all ports + * @limit_vfs: Number of VFs supported by firmware (~0 for PCI limit) * @num_vfs: Number of SR-IOV VFs enabled * @fw_loaded: Is the firmware loaded? * @eth_tbl: NSP ETH table @@ -77,6 +78,7 @@ struct nfp_pf { struct msix_entry *irq_entries; + unsigned int limit_vfs; unsigned int num_vfs; bool fw_loaded; -- 2.7.4