[dpdk-dev] [PATCH] net/nfp: avoid access to sysfs resource0 file

[Alejandro Lucero <alejandro.lucero@netronome.com>]

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>
---
 drivers/net/nfp/nfpcore/nfp_cpp_pcie_ops.c | 46 ++----------------------------
 1 file changed, 3 insertions(+), 43 deletions(-)

diff --git a/drivers/net/nfp/nfpcore/nfp_cpp_pcie_ops.c b/drivers/net/nfp/nfpcore/nfp_cpp_pcie_ops.c
index b0beb8d..c68d940 100644
--- a/drivers/net/nfp/nfpcore/nfp_cpp_pcie_ops.c
+++ b/drivers/net/nfp/nfpcore/nfp_cpp_pcie_ops.c
@@ -310,13 +310,8 @@ struct nfp_pcie_user {
 		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;
 }
@@ -346,7 +341,6 @@ struct nfp_pcie_user {
 	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;
 		}
@@ -779,9 +773,6 @@ struct nfp6000_area_priv {
 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;
@@ -800,39 +791,16 @@ struct nfp6000_area_priv {
 			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)
 		return -1;
 	if (nfp6000_set_serial(dev, cpp) < 0)
 		return -1;
-	if (nfp6000_set_barsz(desc) < 0)
+	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);
 
@@ -848,16 +816,8 @@ struct nfp6000_area_priv {
 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);
-- 
1.9.1