[dpdk-dev] [PATCH RFC 2/3] eal: don't call rte_eal_iopl_init unconditionnally

[David Marchand <david.marchand@6wind.com>]

There is no need for ioport access for applications that won't use virtio pmds.
Make rte_eal_iopl_init() non-static so that it is called from pmds that need it.

Signed-off-by: David Marchand <david.marchand@6wind.com>
---
 lib/librte_eal/bsdapp/eal/eal.c         |    5 +----
 lib/librte_eal/common/include/rte_eal.h |   14 +++++++++++---
 lib/librte_eal/linuxapp/eal/eal.c       |   11 ++++-------
 lib/librte_pmd_virtio/virtio_ethdev.c   |   15 ++++++++-------
 4 files changed, 24 insertions(+), 21 deletions(-)

diff --git a/lib/librte_eal/bsdapp/eal/eal.c b/lib/librte_eal/bsdapp/eal/eal.c
index 0697b05..dad9e0c 100644
--- a/lib/librte_eal/bsdapp/eal/eal.c
+++ b/lib/librte_eal/bsdapp/eal/eal.c
@@ -803,7 +803,7 @@ int rte_eal_has_hugepages(void)
 }
 
 /* Abstraction for port I/0 privilege */
-static int
+int
 rte_eal_iopl_init(void)
 {
 	int fd = -1;
@@ -864,9 +864,6 @@ rte_eal_init(int argc, char **argv)
 
 	rte_config_init();
 
-	if (rte_eal_iopl_init() == 0)
-		rte_config.flags |= EAL_FLG_HIGH_IOPL;
-
 	if (rte_eal_cpu_init() < 0)
 		rte_panic("Cannot detect lcores\n");
 
diff --git a/lib/librte_eal/common/include/rte_eal.h b/lib/librte_eal/common/include/rte_eal.h
index 273da9a..8d39cba 100644
--- a/lib/librte_eal/common/include/rte_eal.h
+++ b/lib/librte_eal/common/include/rte_eal.h
@@ -88,9 +88,6 @@ struct rte_config {
 	struct rte_mem_config *mem_config;
 } __attribute__((__packed__));
 
-/* Flag definitions for rte_config flags */
-#define EAL_FLG_HIGH_IOPL 1 /**< indicates high IO privilege in a linux env */
-
 /**
  * Get the global configuration structure.
  *
@@ -119,6 +116,17 @@ enum rte_lcore_role_t rte_eal_lcore_role(unsigned lcore_id);
 enum rte_proc_type_t rte_eal_process_type(void);
 
 /**
+ * Request iopl privilege for all RPL.
+ *
+ * This function should be called by pmds which need access to ioports.
+
+ * @return
+ *   - On success, returns 0.
+ *   - On failure, returns -1.
+ */
+int rte_eal_iopl_init(void);
+
+/**
  * Initialize the Environment Abstraction Layer (EAL).
  *
  * This function is to be executed on the MASTER lcore only, as soon
diff --git a/lib/librte_eal/linuxapp/eal/eal.c b/lib/librte_eal/linuxapp/eal/eal.c
index 2940e69..884aa9b 100644
--- a/lib/librte_eal/linuxapp/eal/eal.c
+++ b/lib/librte_eal/linuxapp/eal/eal.c
@@ -107,8 +107,6 @@
 
 #define SOCKET_MEM_STRLEN (RTE_MAX_NUMA_NODES * 10)
 
-#define HIGHEST_RPL 3
-
 #define BITS_PER_HEX 4
 
 /* Allow the application to print its usage message too if set */
@@ -1060,10 +1058,12 @@ rte_eal_mcfg_complete(void)
 /*
  * Request iopl privilege for all RPL, returns 0 on success
  */
-static int
+int
 rte_eal_iopl_init(void)
 {
-	return iopl(HIGHEST_RPL);
+	if (iopl(3) != 0)
+		return -1;
+	return 0;
 }
 
 /* Launch threads, called at application init(). */
@@ -1125,9 +1125,6 @@ rte_eal_init(int argc, char **argv)
 
 	rte_config_init();
 
-	if (rte_eal_iopl_init() == 0)
-		rte_config.flags |= EAL_FLG_HIGH_IOPL;
-
 	if (rte_eal_pci_init() < 0)
 		rte_panic("Cannot init PCI\n");
 
diff --git a/lib/librte_pmd_virtio/virtio_ethdev.c b/lib/librte_pmd_virtio/virtio_ethdev.c
index 3344ffb..587b746 100644
--- a/lib/librte_pmd_virtio/virtio_ethdev.c
+++ b/lib/librte_pmd_virtio/virtio_ethdev.c
@@ -736,12 +736,6 @@ eth_virtio_dev_init(__rte_unused struct eth_driver *eth_drv,
 		return -1;
 	}
 
-	if (!(rte_eal_get_configuration()->flags & EAL_FLG_HIGH_IOPL)) {
-		PMD_INIT_LOG(ERR,
-			"IOPL call failed in EAL init - cannot use virtio PMD driver\n");
-		return -1;
-	}
-
 	eth_dev->dev_ops = &virtio_eth_dev_ops;
 	eth_dev->tx_pkt_burst = &virtio_xmit_pkts;
 
@@ -896,8 +890,15 @@ static struct eth_driver rte_virtio_pmd = {
  * Returns 0 on success.
  */
 static int
-rte_virtio_pmd_init(const char *name __rte_unused, const char *param __rte_unused)
+rte_virtio_pmd_init(const char *name __rte_unused,
+		    const char *param __rte_unused)
 {
+	if (rte_eal_iopl_init() != 0) {
+		PMD_INIT_LOG(ERR, "IOPL call failed - "
+				  "cannot use virtio PMD driver\n");
+		return -1;
+	}
+
 	rte_eth_driver_register(&rte_virtio_pmd);
 	return 0;
 }
-- 
1.7.10.4