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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,
	Rafal Kozik <rk@semihalf.com>
Subject: [dpdk-dev] [PATCH v2 1/4] igb_uio: add wc option
Date: Thu, 28 Jun 2018 15:15:50 +0200	[thread overview]
Message-ID: <1530191753-18689-2-git-send-email-rk@semihalf.com> (raw)
In-Reply-To: <1530191753-18689-1-git-send-email-rk@semihalf.com>

Write combining (WC) increases NIC performance by making better
utilization of PCI bus, but cannot be use by all PMDs.

To get internal_addr memory need to be mapped. But as memory could not be
mapped twice: with and without WC, it should be skipped for WC. [1]

To do not spoil other drivers that potentially could use internal_addr,
parameter wc_activate adds possibility to skip it for those PMDs,
that do not use it.

[1] https://www.kernel.org/doc/ols/2008/ols2008v2-pages-135-144.pdf
	section 5.3 and 5.4

Signed-off-by: Rafal Kozik <rk@semihalf.com>
Acked-by: Bruce Richardson <bruce.richardson@intel.com>
---
 kernel/linux/igb_uio/igb_uio.c | 17 ++++++++++++++---
 1 file changed, 14 insertions(+), 3 deletions(-)

diff --git a/kernel/linux/igb_uio/igb_uio.c b/kernel/linux/igb_uio/igb_uio.c
index b3233f1..3382fb1 100644
--- a/kernel/linux/igb_uio/igb_uio.c
+++ b/kernel/linux/igb_uio/igb_uio.c
@@ -30,6 +30,7 @@ struct rte_uio_pci_dev {
 	int refcnt;
 };
 
+static int wc_activate;
 static char *intr_mode;
 static enum rte_intr_mode igbuio_intr_mode_preferred = RTE_INTR_MODE_MSIX;
 /* sriov sysfs */
@@ -375,9 +376,13 @@ igbuio_pci_setup_iomem(struct pci_dev *dev, struct uio_info *info,
 	len = pci_resource_len(dev, pci_bar);
 	if (addr == 0 || len == 0)
 		return -1;
-	internal_addr = ioremap(addr, len);
-	if (internal_addr == NULL)
-		return -1;
+	if (wc_activate == 0) {
+		internal_addr = ioremap(addr, len);
+		if (internal_addr == NULL)
+			return -1;
+	} else {
+		internal_addr = NULL;
+	}
 	info->mem[n].name = name;
 	info->mem[n].addr = addr;
 	info->mem[n].internal_addr = internal_addr;
@@ -650,6 +655,12 @@ MODULE_PARM_DESC(intr_mode,
 "    " RTE_INTR_MODE_LEGACY_NAME "     Use Legacy interrupt\n"
 "\n");
 
+module_param(wc_activate, int, 0);
+MODULE_PARM_DESC(wc_activate,
+"Activate support for write combining (WC) (default=0)\n"
+"    0 - disable\n"
+"    other - enable\n");
+
 MODULE_DESCRIPTION("UIO driver for Intel IGB PCI cards");
 MODULE_LICENSE("GPL");
 MODULE_AUTHOR("Intel Corporation");
-- 
2.7.4

  reply	other threads:[~2018-06-28 13:16 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         ` Rafal Kozik [this message]
2018-06-28 14:32           ` [dpdk-dev] [PATCH v2 1/4] igb_uio: add wc option 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                 ` [dpdk-dev] [PATCH v4 3/4] eal: enable WC during resources mapping Rafal Kozik
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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