From mboxrd@z Thu Jan 1 00:00:00 1970 From: Rafal Kozik Subject: [PATCH v3 3/4] eal: enable WC during resources mapping Date: Fri, 29 Jun 2018 12:24:32 +0200 Message-ID: <1530267873-7236-4-git-send-email-rk@semihalf.com> References: <1530191753-18689-2-git-send-email-rk@semihalf.com> <1530267873-7236-1-git-send-email-rk@semihalf.com> Cc: mw@semihalf.com, mk@semihalf.com, gtzalik@amazon.com, evgenys@amazon.com, matua@amazon.com, igorch@amazon.com, thomas@monjalon.net, ferruh.yigit@intel.com, Rafal Kozik To: dev@dpdk.org Return-path: Received: from mail-lf0-f68.google.com (mail-lf0-f68.google.com [209.85.215.68]) by dpdk.org (Postfix) with ESMTP id E39C51B4DE for ; Fri, 29 Jun 2018 12:24:43 +0200 (CEST) Received: by mail-lf0-f68.google.com with SMTP id n96-v6so6437946lfi.1 for ; Fri, 29 Jun 2018 03:24:43 -0700 (PDT) In-Reply-To: <1530267873-7236-1-git-send-email-rk@semihalf.com> List-Id: DPDK patches and discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dev-bounces@dpdk.org Sender: "dev" Write combining (WC) increases NIC performance by making better utilization of PCI bus, but cannot be used by all PMDs. It will be enabled only if RTE_PCI_DRV_WC_ACTIVATE will be set in drivers flags. For proper work also igb_uio driver must be loaded with wc_activate set to 1. When mapping PCI resources, firstly try to us WC. If it is not supported it will fallback to normal mode. Signed-off-by: Rafal Kozik Acked-by: Bruce Richardson --- drivers/bus/pci/linux/pci_uio.c | 44 ++++++++++++++++++++++++++++++----------- drivers/bus/pci/rte_bus_pci.h | 2 ++ 2 files changed, 34 insertions(+), 12 deletions(-) diff --git a/drivers/bus/pci/linux/pci_uio.c b/drivers/bus/pci/linux/pci_uio.c index d423e4b..fb02f0a 100644 --- a/drivers/bus/pci/linux/pci_uio.c +++ b/drivers/bus/pci/linux/pci_uio.c @@ -282,22 +282,19 @@ int pci_uio_map_resource_by_index(struct rte_pci_device *dev, int res_idx, struct mapped_pci_resource *uio_res, int map_idx) { - int fd; + int fd = -1; char devname[PATH_MAX]; void *mapaddr; struct rte_pci_addr *loc; struct pci_map *maps; + int wc_activate = 0; + + if (dev->driver != NULL) + wc_activate = dev->driver->drv_flags & RTE_PCI_DRV_WC_ACTIVATE; loc = &dev->addr; maps = uio_res->maps; - /* update devname for mmap */ - snprintf(devname, sizeof(devname), - "%s/" PCI_PRI_FMT "/resource%d", - rte_pci_get_sysfs_path(), - loc->domain, loc->bus, loc->devid, - loc->function, res_idx); - /* allocate memory to keep path */ maps[map_idx].path = rte_malloc(NULL, strlen(devname) + 1, 0); if (maps[map_idx].path == NULL) { @@ -309,11 +306,34 @@ pci_uio_map_resource_by_index(struct rte_pci_device *dev, int res_idx, /* * open resource file, to mmap it */ - fd = open(devname, O_RDWR); - if (fd < 0) { - RTE_LOG(ERR, EAL, "Cannot open %s: %s\n", + if (wc_activate) { + /* update devname for mmap */ + snprintf(devname, sizeof(devname), + "%s/" PCI_PRI_FMT "/resource%d_wc", + rte_pci_get_sysfs_path(), + loc->domain, loc->bus, loc->devid, + loc->function, res_idx); + + fd = open(devname, O_RDWR); + if (fd >= 0) + RTE_LOG(INFO, EAL, "%s mapped\n", devname); + } + + if (!wc_activate || fd < 0) { + snprintf(devname, sizeof(devname), + "%s/" PCI_PRI_FMT "/resource%d", + rte_pci_get_sysfs_path(), + loc->domain, loc->bus, loc->devid, + loc->function, res_idx); + + /* then try to map resource file */ + fd = open(devname, O_RDWR); + if (fd < 0) { + RTE_LOG(ERR, EAL, "Cannot open %s: %s\n", devname, strerror(errno)); - goto error; + goto error; + } + RTE_LOG(INFO, EAL, "%s mapped\n", devname); } /* try mapping somewhere close to the end of hugepages */ diff --git a/drivers/bus/pci/rte_bus_pci.h b/drivers/bus/pci/rte_bus_pci.h index 458e6d0..828acc5 100644 --- a/drivers/bus/pci/rte_bus_pci.h +++ b/drivers/bus/pci/rte_bus_pci.h @@ -135,6 +135,8 @@ struct rte_pci_bus { /** Device needs PCI BAR mapping (done with either IGB_UIO or VFIO) */ #define RTE_PCI_DRV_NEED_MAPPING 0x0001 +/** Device needs PCI BAR mapping with enabled write combining (wc) */ +#define RTE_PCI_DRV_WC_ACTIVATE 0x0002 /** Device driver supports link state interrupt */ #define RTE_PCI_DRV_INTR_LSC 0x0008 /** Device driver supports device removal interrupt */ -- 2.7.4