From 7ecfd061afed55cbbd5c82802bc288ed67bf2cb3 Mon Sep 17 00:00:00 2001
From: Alejandro Lucero <alejandro.lucero@netronome.com>
Date: Tue, 26 Jun 2018 14:29:21 +0100
Subject: [PATCH 2/2] net/nfp: avoid access to sysfs resource0 file

NFP CPP interface dinamically configures NFP CPP BARs for accessing
any NFP chip component from user space. This requires to map PCI BAR
regions specifically. However, this does not require to do such map
over the usual map done by VFIO or UIO drivers with the device PCI
BARs.

This patch avoids this remapping and therefore also avoids to access
the device sysfs resource0 file for doing that remapping.

Signed-off-by: Alejandro Lucero <alejandro.lucero@netronome.com>
(cherry picked from commit a28fb7bef424d3b96ff13b996de7ed8775c67542)
---
 drivers/net/nfp/nfpcore/nfp_cpp_pcie_ops.c | 44 +---------------------
 1 file changed, 2 insertions(+), 42 deletions(-)

diff --git a/drivers/net/nfp/nfpcore/nfp_cpp_pcie_ops.c b/drivers/net/nfp/nfpcore/nfp_cpp_pcie_ops.c
index 9accc89cf..73124487a 100644
--- a/drivers/net/nfp/nfpcore/nfp_cpp_pcie_ops.c
+++ b/drivers/net/nfp/nfpcore/nfp_cpp_pcie_ops.c
@@ -309,13 +309,8 @@ nfp_enable_bars(struct nfp_pcie_user *nfp)
 		bar->csr = nfp->cfg +
 			   NFP_PCIE_CFG_BAR_PCIETOCPPEXPBAR(bar->index >> 3,
 							   bar->index & 7);
-		bar->iomem =
-		    (char *)mmap(0, 1 << bar->bitsize, PROT_READ | PROT_WRITE,
-				 MAP_SHARED, nfp->device,
-				 bar->index << bar->bitsize);
 
-		if (bar->iomem == MAP_FAILED)
-			return (-ENOMEM);
+		bar->iomem = nfp->cfg + (bar->index << bar->bitsize);
 	}
 	return 0;
 }
@@ -345,7 +340,6 @@ nfp_disable_bars(struct nfp_pcie_user *nfp)
 	for (x = ARRAY_SIZE(nfp->bar); x > 0; x--) {
 		bar = &nfp->bar[x - 1];
 		if (bar->iomem) {
-			munmap(bar->iomem, 1 << (nfp->barsz - 3));
 			bar->iomem = NULL;
 			bar->lock = 0;
 		}
@@ -778,9 +772,6 @@ nfp6000_set_barsz(struct rte_pci_device *dev, struct nfp_pcie_user *desc)
 static int
 nfp6000_init(struct nfp_cpp *cpp, struct rte_pci_device *dev)
 {
-	char link[120];
-	char tmp_str[80];
-	ssize_t size;
 	int ret = 0;
 	uint32_t model;
 	struct nfp_pcie_user *desc;
@@ -799,24 +790,6 @@ nfp6000_init(struct nfp_cpp *cpp, struct rte_pci_device *dev)
 			return -1;
 	}
 
-	snprintf(tmp_str, sizeof(tmp_str), "%s/%s/driver", PCI_DEVICES,
-		 desc->busdev);
-
-	size = readlink(tmp_str, link, sizeof(link));
-
-	if (size == -1)
-		tmp_str[0] = '\0';
-
-	if (size == sizeof(link))
-		tmp_str[0] = '\0';
-
-	snprintf(tmp_str, sizeof(tmp_str), "%s/%s/resource0", PCI_DEVICES,
-		 desc->busdev);
-
-	desc->device = open(tmp_str, O_RDWR);
-	if (desc->device == -1)
-		return -1;
-
 	if (nfp6000_set_model(dev, cpp) < 0)
 		return -1;
 	if (nfp6000_set_interface(dev, cpp) < 0)
@@ -826,12 +799,7 @@ nfp6000_init(struct nfp_cpp *cpp, struct rte_pci_device *dev)
 	if (nfp6000_set_barsz(dev, desc) < 0)
 		return -1;
 
-	desc->cfg = (char *)mmap(0, 1 << (desc->barsz - 3),
-				 PROT_READ | PROT_WRITE,
-				 MAP_SHARED, desc->device, 0);
-
-	if (desc->cfg == MAP_FAILED)
-		return -1;
+	desc->cfg = (char *)dev->mem_resource[0].addr;
 
 	nfp_enable_bars(desc);
 
@@ -847,16 +815,8 @@ static void
 nfp6000_free(struct nfp_cpp *cpp)
 {
 	struct nfp_pcie_user *desc = nfp_cpp_priv(cpp);
-	int x;
 
-	/* Unmap may cause if there are any pending transaxctions */
 	nfp_disable_bars(desc);
-	munmap(desc->cfg, 1 << (desc->barsz - 3));
-
-	for (x = ARRAY_SIZE(desc->bar); x > 0; x--) {
-		if (desc->bar[x - 1].iomem)
-			munmap(desc->bar[x - 1].iomem, 1 << (desc->barsz - 3));
-	}
 	if (cpp->driver_lock_needed)
 		close(desc->lock);
 	close(desc->device);
-- 
2.17.1