[dpdk-dev] [PATCH v2 1/2] eal: mmap uio resources using resourceX files

[Bruce Richardson <bruce.richardson@intel.com>]

Instead of distinguishing the BAR mappings via offset within a single
file, originally /dev/uioX, switch to mapping each individual bar via
the appropriately numbered resourceX file.

Signed-off-by: Bruce Richardson <bruce.richardson@intel.com>
---
 lib/librte_eal/common/include/rte_pci.h    |  2 +-
 lib/librte_eal/linuxapp/eal/eal_pci_init.h |  1 +
 lib/librte_eal/linuxapp/eal/eal_pci_uio.c  | 34 ++++++++++++++++--------------
 lib/librte_eal/linuxapp/eal/eal_pci_vfio.c |  1 +
 4 files changed, 21 insertions(+), 17 deletions(-)

diff --git a/lib/librte_eal/common/include/rte_pci.h b/lib/librte_eal/common/include/rte_pci.h
index 4301c16..e34b139 100644
--- a/lib/librte_eal/common/include/rte_pci.h
+++ b/lib/librte_eal/common/include/rte_pci.h
@@ -117,7 +117,7 @@ struct rte_pci_resource {
 };
 
 /** Maximum number of PCI resources. */
-#define PCI_MAX_RESOURCE 7
+#define PCI_MAX_RESOURCE 6
 
 /**
  * A structure describing an ID for a PCI driver. Each driver provides a
diff --git a/lib/librte_eal/linuxapp/eal/eal_pci_init.h b/lib/librte_eal/linuxapp/eal/eal_pci_init.h
index 1070eb8..2125d7b 100644
--- a/lib/librte_eal/linuxapp/eal/eal_pci_init.h
+++ b/lib/librte_eal/linuxapp/eal/eal_pci_init.h
@@ -38,6 +38,7 @@
 
 struct pci_map {
 	void *addr;
+	char *path;
 	uint64_t offset;
 	uint64_t size;
 	uint64_t phaddr;
diff --git a/lib/librte_eal/linuxapp/eal/eal_pci_uio.c b/lib/librte_eal/linuxapp/eal/eal_pci_uio.c
index 2b16fcb..ecf385a 100644
--- a/lib/librte_eal/linuxapp/eal/eal_pci_uio.c
+++ b/lib/librte_eal/linuxapp/eal/eal_pci_uio.c
@@ -137,10 +137,10 @@ pci_uio_map_secondary(struct rte_pci_device *dev)
 			/*
 			 * open devname, to mmap it
 			 */
-			fd = open(uio_res->path, O_RDWR);
+			fd = open(uio_res->maps[i].path, O_RDWR);
 			if (fd < 0) {
 				RTE_LOG(ERR, EAL, "Cannot open %s: %s\n",
-					uio_res->path, strerror(errno));
+					uio_res->maps[i].path, strerror(errno));
 				return -1;
 			}
 
@@ -149,7 +149,8 @@ pci_uio_map_secondary(struct rte_pci_device *dev)
 					     (size_t)uio_res->maps[i].size)
 			    != uio_res->maps[i].addr) {
 				RTE_LOG(ERR, EAL,
-					"Cannot mmap device resource\n");
+					"Cannot mmap device resource file: %s\n",
+					uio_res->maps[i].path);
 				close(fd);
 				return -1;
 			}
@@ -294,8 +295,6 @@ pci_uio_map_resource(struct rte_pci_device *dev)
 	void *mapaddr;
 	int uio_num;
 	uint64_t phaddr;
-	uint64_t offset;
-	uint64_t pagesz;
 	int nb_maps;
 	struct rte_pci_addr *loc = &dev->addr;
 	struct mapped_pci_resource *uio_res;
@@ -336,11 +335,6 @@ pci_uio_map_resource(struct rte_pci_device *dev)
 		return -1;
 	}
 
-	/* update devname for mmap  */
-	snprintf(devname, sizeof(devname),
-		SYSFS_PCI_DEVICES "/" PCI_PRI_FMT "/resource%d",
-		loc->domain, loc->bus, loc->devid, loc->function, 0);
-
 	/* set bus master that is not done by uio_pci_generic */
 	if (rte_eal_process_type() == RTE_PROC_PRIMARY) {
 		if (pci_uio_set_bus_master(dev->intr_handle.uio_cfg_fd)) {
@@ -370,8 +364,6 @@ pci_uio_map_resource(struct rte_pci_device *dev)
 	uio_res->nb_maps = nb_maps;
 
 	/* Map all BARs */
-	pagesz = sysconf(_SC_PAGESIZE);
-
 	maps = uio_res->maps;
 	for (i = 0; i != PCI_MAX_RESOURCE; i++) {
 		int fd;
@@ -389,10 +381,15 @@ pci_uio_map_resource(struct rte_pci_device *dev)
 		/* if matching map is found, then use it */
 		if (j != nb_maps) {
 			int fail = 0;
-			offset = j * pagesz;
+
+			/* update devname for mmap  */
+			snprintf(devname, sizeof(devname),
+				SYSFS_PCI_DEVICES "/" PCI_PRI_FMT "/resource%d",
+				loc->domain, loc->bus, loc->devid, loc->function,
+				i);
 
 			/*
-			 * open devname, to mmap it
+			 * open resource file, to mmap it
 			 */
 			fd = open(devname, O_RDWR);
 			if (fd < 0) {
@@ -408,7 +405,7 @@ pci_uio_map_resource(struct rte_pci_device *dev)
 				if (pci_map_addr == NULL)
 					pci_map_addr = pci_find_max_end_va();
 
-				mapaddr = pci_map_resource(pci_map_addr, fd, (off_t)offset,
+				mapaddr = pci_map_resource(pci_map_addr, fd, 0,
 						(size_t)maps[j].size);
 				if (mapaddr == MAP_FAILED)
 					fail = 1;
@@ -416,6 +413,10 @@ pci_uio_map_resource(struct rte_pci_device *dev)
 				pci_map_addr = RTE_PTR_ADD(mapaddr, (size_t) maps[j].size);
 			}
 
+			maps[j].path = rte_malloc(NULL, strlen(devname) + 1, 0);
+			if (maps[j].path == NULL)
+				fail = 1;
+
 			if (fail) {
 				rte_free(uio_res);
 				close(fd);
@@ -424,7 +425,8 @@ pci_uio_map_resource(struct rte_pci_device *dev)
 			close(fd);
 
 			maps[j].addr = mapaddr;
-			maps[j].offset = offset;
+			maps[j].offset = 0;
+			strcpy(maps[j].path, devname);
 			dev->mem_resource[i].addr = mapaddr;
 		}
 	}
diff --git a/lib/librte_eal/linuxapp/eal/eal_pci_vfio.c b/lib/librte_eal/linuxapp/eal/eal_pci_vfio.c
index 20e0977..7a57d0f 100644
--- a/lib/librte_eal/linuxapp/eal/eal_pci_vfio.c
+++ b/lib/librte_eal/linuxapp/eal/eal_pci_vfio.c
@@ -751,6 +751,7 @@ pci_vfio_map_resource(struct rte_pci_device *dev)
 		maps[i].addr = bar_addr;
 		maps[i].offset = reg.offset;
 		maps[i].size = reg.size;
+		maps[i].path = NULL; /* vfio doesn't have per-resource paths */
 		dev->mem_resource[i].addr = bar_addr;
 	}
 
-- 
2.1.0