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From: Rafal Kozik <rk@semihalf.com>
To: dev@dpdk.org
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,
	Kozik <rk@semihalf.com>
Subject: [dpdk-dev] [PATCH v4 3/4] eal: enable WC during resources mapping
Date: Fri, 29 Jun 2018 14:17:16 +0200	[thread overview]
Message-ID: <1530274637-10156-4-git-send-email-rk@semihalf.com> (raw)
In-Reply-To: <1530274637-10156-1-git-send-email-rk@semihalf.com>

From: Kozik <rk@semihalf.com>

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 check if it supports WC
and try to use it.
In case of failure, it will fall-back to normal mode.

Signed-off-by: Rafal Kozik <rk@semihalf.com>
Acked-by: Bruce Richardson <bruce.richardson@intel.com>
---
 drivers/bus/pci/linux/pci_uio.c | 47 ++++++++++++++++++++++++++++++-----------
 drivers/bus/pci/rte_bus_pci.h   |  2 ++
 2 files changed, 37 insertions(+), 12 deletions(-)

diff --git a/drivers/bus/pci/linux/pci_uio.c b/drivers/bus/pci/linux/pci_uio.c
index d423e4b..a7c1442 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 +306,37 @@ 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);
+
+		if (access(devname, R_OK|W_OK) != -1) {
+			fd = open(devname, O_RDWR);
+			if (fd < 0)
+				RTE_LOG(INFO, EAL, "%s cannot be mapped. "
+					"Fall-back to non prefetchable mode.\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;
+		}
 	}
 
 	/* 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

  parent reply	other threads:[~2018-06-29 12:17 UTC|newest]

Thread overview: 54+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-04-11 14:07 [dpdk-dev] [PATCH 0/4] support for write combining Rafal Kozik
2018-04-11 14:07 ` [dpdk-dev] [PATCH 1/4] igb_uio: add wc option Rafal Kozik
2018-06-27 16:34   ` Ferruh Yigit
2018-06-28 13:08     ` Rafał Kozik
2018-06-28 13:15       ` [dpdk-dev] [PATCH v2 0/4] support for write combining Rafal Kozik
2018-06-28 13:15         ` [dpdk-dev] [PATCH v2 1/4] igb_uio: add wc option Rafal Kozik
2018-06-28 14:32           ` Ferruh Yigit
2018-06-29  8:35             ` Rafał Kozik
2018-06-29 10:08               ` Ferruh Yigit
2018-06-29 10:24           ` [dpdk-dev] [PATCH v3 0/4] support for write combining Rafal Kozik
2018-06-29 10:24             ` [dpdk-dev] [PATCH v3 1/4] igb_uio: add wc option Rafal Kozik
2018-06-29 10:53               ` Ferruh Yigit
2018-06-29 12:17               ` [dpdk-dev] [PATCH v4 0/4] Support for write combining Rafal Kozik
2018-06-29 12:17                 ` [dpdk-dev] [PATCH v4 1/4] igb_uio: add wc option Rafal Kozik
2018-06-29 13:11                   ` Rafał Kozik
2018-06-29 13:20                   ` Ferruh Yigit
2018-06-29 13:40                   ` Ferruh Yigit
2018-06-29 12:17                 ` [dpdk-dev] [PATCH v4 2/4] bus/pci: reference driver structure Rafal Kozik
2018-06-29 12:17                 ` Rafal Kozik [this message]
2018-06-29 12:17                 ` [dpdk-dev] [PATCH v4 4/4] net/ena: enable WC Rafal Kozik
2018-06-29 13:54               ` [dpdk-dev] [PATCH v5 0/4] Support for write combining Rafal Kozik
2018-06-29 13:54                 ` [dpdk-dev] [PATCH v5 1/4] igb_uio: add wc option Rafal Kozik
2018-06-29 13:54                 ` [dpdk-dev] [PATCH v5 2/4] bus/pci: reference driver structure Rafal Kozik
2018-06-29 13:54                 ` [dpdk-dev] [PATCH v5 3/4] eal: enable WC during resources mapping Rafal Kozik
2018-06-29 13:54                 ` [dpdk-dev] [PATCH v5 4/4] net/ena: enable WC Rafal Kozik
2018-06-29 14:26                 ` [dpdk-dev] [PATCH v5 0/4] Support for write combining Ferruh Yigit
2018-06-29 22:13                   ` Thomas Monjalon
2018-06-29 10:24             ` [dpdk-dev] [PATCH v3 2/4] bus/pci: reference driver structure Rafal Kozik
2018-06-29 10:24             ` [dpdk-dev] [PATCH v3 3/4] eal: enable WC during resources mapping Rafal Kozik
2018-06-29 10:24             ` [dpdk-dev] [PATCH v3 4/4] net/ena: enable WC Rafal Kozik
2018-06-28 13:15         ` [dpdk-dev] [PATCH v2 2/4] bus/pci: reference driver structure Rafal Kozik
2018-06-28 13:15         ` [dpdk-dev] [PATCH v2 3/4] eal: enable WC during resources mapping Rafal Kozik
2018-06-28 14:50           ` Ferruh Yigit
2018-06-29  8:58             ` Rafał Kozik
2018-06-29  9:05               ` Ferruh Yigit
2018-06-29 10:28                 ` Rafał Kozik
2018-06-29 10:37                   ` Ferruh Yigit
2018-06-28 13:15         ` [dpdk-dev] [PATCH v2 4/4] net/ena: enable WC Rafal Kozik
2018-07-02  6:52           ` Michał Krawczyk
2018-04-11 14:07 ` [dpdk-dev] [PATCH 2/4] bus/pci: reference driver structure Rafal Kozik
2018-06-27 16:36   ` Ferruh Yigit
2018-06-28 13:05     ` Rafał Kozik
2018-04-11 14:07 ` [dpdk-dev] [PATCH 3/4] eal: enable WC during resources mapping Rafal Kozik
2018-06-27 16:41   ` Ferruh Yigit
2018-06-28 13:06     ` Rafał Kozik
2018-04-11 14:07 ` [dpdk-dev] [PATCH 4/4] net/ena: enable WC Rafal Kozik
2018-06-27 16:11   ` Thomas Monjalon
2018-06-28 13:04     ` Rafał Kozik
2018-04-11 14:42 ` [dpdk-dev] [PATCH 0/4] support for write combining Bruce Richardson
2018-04-16 11:36   ` Rafał Kozik
2018-04-27  8:27     ` Rafał Kozik
2018-04-27 11:30       ` Bruce Richardson
2018-04-30  8:07         ` Rafał Kozik
2018-04-30  8:58           ` Bruce Richardson

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