From 552ff0a9afc2d41685ed0295e6080df0c05382b4 Mon Sep 17 00:00:00 2001
From: Alejandro Lucero <alejandro.lucero@netronome.com>
Date: Wed, 23 May 2018 13:28:56 +0100
Subject: [PATCH] net/nfp: fix lock file usage

DPDK apps can be executed as non-root users but current NFP lock
file for avoiding concurrent accesses to CPP interface is precluding
this option or requires to modify system file permissions.

When the NFP device is bound to VFIO, this driver does not allow this
concurrent access, so the lock file is not required at all.

OVS-DPDK as executed in RedHat distributions is the main NFP user
needing this fix.

Fixes: c7e9729da6b5 ("net/nfp: support CPP")

Signed-off-by: Alejandro Lucero <alejandro.lucero@netronome.com>
(cherry picked from commit 5f6ed2f4e0cb79580c0bedba2bd764a39923d7ec)
---
 drivers/net/nfp/nfp_net.c                  | 13 ++++++++++++-
 drivers/net/nfp/nfpcore/nfp_cpp.h          |  5 ++++-
 drivers/net/nfp/nfpcore/nfp_cpp_pcie_ops.c | 11 +++++++----
 drivers/net/nfp/nfpcore/nfp_cppcore.c      |  7 ++++---
 4 files changed, 27 insertions(+), 9 deletions(-)

diff --git a/drivers/net/nfp/nfp_net.c b/drivers/net/nfp/nfp_net.c
index 559230ab6..71249572d 100644
--- a/drivers/net/nfp/nfp_net.c
+++ b/drivers/net/nfp/nfp_net.c
@@ -3146,7 +3146,18 @@ static int nfp_pf_pci_probe(struct rte_pci_driver *pci_drv __rte_unused,
 	if (!dev)
 		return ret;
 
-	cpp = nfp_cpp_from_device_name(dev->device.name);
+	/*
+	 * When device bound to UIO, the device could be used, by mistake,
+	 * by two DPDK apps, and the UIO driver does not avoid it. This
+	 * could lead to a serious problem when configuring the NFP CPP
+	 * interface. Here we avoid this telling to the CPP init code to
+	 * use a lock file if UIO is being used.
+	 */
+	if (dev->kdrv == RTE_KDRV_VFIO)
+		cpp = nfp_cpp_from_device_name(dev->device.name, 0);
+	else
+		cpp = nfp_cpp_from_device_name(dev->device.name, 1);
+
 	if (!cpp) {
 		RTE_LOG(ERR, PMD, "A CPP handle can not be obtained");
 		ret = -EIO;
diff --git a/drivers/net/nfp/nfpcore/nfp_cpp.h b/drivers/net/nfp/nfpcore/nfp_cpp.h
index 7e862145c..de2ff84e9 100644
--- a/drivers/net/nfp/nfpcore/nfp_cpp.h
+++ b/drivers/net/nfp/nfpcore/nfp_cpp.h
@@ -31,6 +31,8 @@ struct nfp_cpp {
 	 * island XPB CSRs.
 	 */
 	uint32_t imb_cat_table[16];
+
+	int driver_lock_needed;
 };
 
 /*
@@ -179,7 +181,8 @@ uint32_t __nfp_cpp_model_autodetect(struct nfp_cpp *cpp);
  *
  * @return NFP CPP handle, or NULL on failure (and set errno accordingly).
  */
-struct nfp_cpp *nfp_cpp_from_device_name(const char *devname);
+struct nfp_cpp *nfp_cpp_from_device_name(const char *devname,
+					 int driver_lock_needed);
 
 /*
  * Free a NFP CPP handle
diff --git a/drivers/net/nfp/nfpcore/nfp_cpp_pcie_ops.c b/drivers/net/nfp/nfpcore/nfp_cpp_pcie_ops.c
index ad6ce72fe..e46dbc7d7 100644
--- a/drivers/net/nfp/nfpcore/nfp_cpp_pcie_ops.c
+++ b/drivers/net/nfp/nfpcore/nfp_cpp_pcie_ops.c
@@ -848,9 +848,11 @@ nfp6000_init(struct nfp_cpp *cpp, const char *devname)
 	memset(desc->busdev, 0, BUSDEV_SZ);
 	strncpy(desc->busdev, devname, strlen(devname));
 
-	ret = nfp_acquire_process_lock(desc);
-	if (ret)
-		return -1;
+	if (cpp->driver_lock_needed) {
+		ret = nfp_acquire_process_lock(desc);
+		if (ret)
+			return -1;
+	}
 
 	snprintf(tmp_str, sizeof(tmp_str), "%s/%s/driver", PCI_DEVICES,
 		 desc->busdev);
@@ -910,7 +912,8 @@ nfp6000_free(struct nfp_cpp *cpp)
 		if (desc->bar[x - 1].iomem)
 			munmap(desc->bar[x - 1].iomem, 1 << (desc->barsz - 3));
 	}
-	close(desc->lock);
+	if (cpp->driver_lock_needed)
+		close(desc->lock);
 	close(desc->device);
 	free(desc);
 }
diff --git a/drivers/net/nfp/nfpcore/nfp_cppcore.c b/drivers/net/nfp/nfpcore/nfp_cppcore.c
index 94d4a0b6b..f61143f7e 100644
--- a/drivers/net/nfp/nfpcore/nfp_cppcore.c
+++ b/drivers/net/nfp/nfpcore/nfp_cppcore.c
@@ -542,7 +542,7 @@ nfp_xpb_readl(struct nfp_cpp *cpp, uint32_t xpb_addr, uint32_t *value)
 }
 
 static struct nfp_cpp *
-nfp_cpp_alloc(const char *devname)
+nfp_cpp_alloc(const char *devname, int driver_lock_needed)
 {
 	const struct nfp_cpp_operations *ops;
 	struct nfp_cpp *cpp;
@@ -558,6 +558,7 @@ nfp_cpp_alloc(const char *devname)
 		return NULL;
 
 	cpp->op = ops;
+	cpp->driver_lock_needed = driver_lock_needed;
 
 	if (cpp->op->init) {
 		err = cpp->op->init(cpp, devname);
@@ -603,9 +604,9 @@ nfp_cpp_free(struct nfp_cpp *cpp)
 }
 
 struct nfp_cpp *
-nfp_cpp_from_device_name(const char *devname)
+nfp_cpp_from_device_name(const char *devname, int driver_lock_needed)
 {
-	return nfp_cpp_alloc(devname);
+	return nfp_cpp_alloc(devname, driver_lock_needed);
 }
 
 /*
-- 
2.17.0