[dpdk-dev] [PATCH 20/22] pci: support reading/writing sys files of 'extended_tag' and 'max_read_request_size'

[Helin Zhang]

Sys files of 'extended_tag' and 'max_read_request_size' are supported by
igb_uio. Reading or writing them to enable/disable 'Extended Tag' or
reset 'Max Read Request Size' automatically according to the configurations
are added.

Signed-off-by: Helin Zhang <helin.zhang at intel.com>
Signed-off-by: Mark Chen <jing.d.chen at intel.com>
---
 lib/librte_eal/linuxapp/eal/eal_pci.c | 101 ++++++++++++++++++++++++++++++++++
 1 file changed, 101 insertions(+)

diff --git a/lib/librte_eal/linuxapp/eal/eal_pci.c b/lib/librte_eal/linuxapp/eal/eal_pci.c
index ac2c1fe..3956e88 100644
--- a/lib/librte_eal/linuxapp/eal/eal_pci.c
+++ b/lib/librte_eal/linuxapp/eal/eal_pci.c
@@ -107,6 +107,11 @@ TAILQ_HEAD(uio_res_list, uio_resource);
 static struct uio_res_list *uio_res_list = NULL;
 static int pci_parse_sysfs_value(const char *filename, uint64_t *val);
 
+
+#ifdef RTE_PCI_CONFIG
+static void pci_config_space_set(struct rte_pci_device *dev);
+#endif
+
 /* unbind kernel driver for this device */
 static int
 pci_unbind_kernel_driver(struct rte_pci_device *dev)
@@ -840,6 +845,13 @@ rte_eal_pci_probe_one_driver(struct rte_pci_driver *dr, struct rte_pci_device *d
 		}
 
 		if (dr->drv_flags & RTE_PCI_DRV_NEED_IGB_UIO) {
+#ifdef RTE_PCI_CONFIG
+			/*
+			 * Set PCIe config space for high performance.
+			 * Return value can be ignored.
+			 */
+			pci_config_space_set(dev);
+#endif
 			/* map resources for devices that use igb_uio */
 			if (pci_uio_map_resource(dev) < 0)
 				return -1;
@@ -878,3 +890,92 @@ rte_eal_pci_init(void)
 	}
 	return 0;
 }
+
+#ifdef RTE_PCI_CONFIG
+static int
+pci_config_extended_tag(struct rte_pci_device *dev)
+{
+	struct rte_pci_addr *loc = &dev->addr;
+	char filename[PATH_MAX];
+	char buf[BUFSIZ];
+	FILE *f;
+
+	/* not configured, let it as is */
+	if (strncmp(RTE_PCI_EXTENDED_TAG, "on", 2) != 0 &&
+		strncmp(RTE_PCI_EXTENDED_TAG, "off", 3) != 0)
+		return 0;
+
+	rte_snprintf(filename, sizeof(filename),
+		SYSFS_PCI_DEVICES "/" PCI_PRI_FMT "/" "extended_tag",
+		loc->domain, loc->bus, loc->devid, loc->function);
+	f = fopen(filename, "rw+");
+	if (!f)
+		return -1;
+
+	fgets(buf, sizeof(buf), f);
+	if (strncmp(RTE_PCI_EXTENDED_TAG, "on", 2) == 0) {
+		/* enable Extended Tag*/
+		if (strncmp(buf, "on", 2) != 0) {
+			fseek(f, 0, SEEK_SET);
+			fputs("on", f);
+		}
+	} else {
+		/* disable Extended Tag */
+		if (strncmp(buf, "off", 3) != 0) {
+			fseek(f, 0, SEEK_SET);
+			fputs("off", f);
+		}
+	}
+	fclose(f);
+
+	return 0;
+}
+
+static int
+pci_config_max_read_request_size(struct rte_pci_device *dev)
+{
+	struct rte_pci_addr *loc = &dev->addr;
+	char filename[PATH_MAX];
+	char buf[BUFSIZ], param[BUFSIZ];
+	FILE *f;
+	uint32_t max_size = RTE_PCI_MAX_READ_REQUEST_SIZE;
+
+	/* not configured, let it as is */
+	if (!max_size)
+		return 0;
+
+	rte_snprintf(filename, sizeof(filename),
+		SYSFS_PCI_DEVICES "/" PCI_PRI_FMT "/" "max_read_request_size",
+			loc->domain, loc->bus, loc->devid, loc->function);
+	f = fopen(filename, "rw+");
+	if (!f)
+		return -1;
+
+	fgets(buf, sizeof(buf), f);
+	rte_snprintf(param, sizeof(param), "%d", max_size);
+
+	/* check if the size to be set is the same as current */
+	if (strcmp(buf, param) == 0) {
+		fclose(f);
+		return 0;
+	}
+	fseek(f, 0, SEEK_SET);
+	fputs(param, f);
+	fclose(f);
+
+	return 0;
+}
+
+static void
+pci_config_space_set(struct rte_pci_device *dev)
+{
+	if (rte_eal_process_type() != RTE_PROC_PRIMARY)
+		return;
+
+	/* configure extended tag */
+	pci_config_extended_tag(dev);
+
+	/* configure max read request size */
+	pci_config_max_read_request_size(dev);
+}
+#endif
-- 
1.8.1.4