[dpdk-dev] [PATCH v8 06/11] eal/linux: standalone intr event fd create support

Cunming Liang cunming.liang at intel.com
Thu May 21 10:55:58 CEST 2015


The patch exposes intr event fd create and release for PMD.
The device driver can assign the number of event associated with interrupt vector.
It also provides misc funtions to check 1) allows other slowpath intr(e.g. lsc);
2) intr event on fastpath is enabled or not.

Signed-off-by: Cunming Liang <cunming.liang at intel.com>
---
 lib/librte_eal/linuxapp/eal/eal_interrupts.c       | 57 ++++++++++++++++++++++
 .../linuxapp/eal/include/exec-env/rte_interrupts.h | 51 +++++++++++++++++++
 lib/librte_eal/linuxapp/eal/rte_eal_version.map    |  4 ++
 3 files changed, 112 insertions(+)

diff --git a/lib/librte_eal/linuxapp/eal/eal_interrupts.c b/lib/librte_eal/linuxapp/eal/eal_interrupts.c
index d1e9013..742fdab 100644
--- a/lib/librte_eal/linuxapp/eal/eal_interrupts.c
+++ b/lib/librte_eal/linuxapp/eal/eal_interrupts.c
@@ -44,6 +44,7 @@
 #include <sys/epoll.h>
 #include <sys/signalfd.h>
 #include <sys/ioctl.h>
+#include <sys/eventfd.h>
 
 #include <rte_common.h>
 #include <rte_interrupts.h>
@@ -68,6 +69,7 @@
 #include "eal_vfio.h"
 
 #define EAL_INTR_EPOLL_WAIT_FOREVER (-1)
+#define NB_OTHER_INTR               1
 
 static RTE_DEFINE_PER_LCORE(int, _epfd) = -1; /**< epoll fd per thread */
 
@@ -1075,3 +1077,58 @@ rte_intr_rx_ctl(struct rte_intr_handle *intr_handle, int epfd,
 
 	return rc;
 }
+
+int
+rte_intr_efd_enable(struct rte_intr_handle *intr_handle, uint32_t nb_efd)
+{
+	uint32_t i;
+	int fd;
+	uint32_t n = RTE_MIN(nb_efd, (uint32_t)RTE_MAX_RXTX_INTR_VEC_ID);
+
+	if (intr_handle->type == RTE_INTR_HANDLE_VFIO_MSIX) {
+		for (i = 0; i < n; i++) {
+			fd = eventfd(0, EFD_NONBLOCK | EFD_CLOEXEC);
+			if (fd < 0) {
+				RTE_LOG(ERR, EAL,
+					"cannot setup eventfd,"
+					"error %i (%s)\n",
+					errno, strerror(errno));
+				return -1;
+			}
+			intr_handle->efds[i] = fd;
+		}
+		intr_handle->nb_efd   = n;
+		intr_handle->max_intr = NB_OTHER_INTR + n;
+	} else {
+		intr_handle->efds[0]  = intr_handle->fd;
+		intr_handle->nb_efd   = RTE_MIN(nb_efd, 1U);
+		intr_handle->max_intr = NB_OTHER_INTR;
+	}
+
+	return 0;
+}
+
+void
+rte_intr_efd_disable(struct rte_intr_handle *intr_handle)
+{
+	uint32_t i;
+	struct rte_epoll_event *rev;
+
+	for (i = 0; i < intr_handle->nb_efd; i++) {
+		rev = &intr_handle->elist[i];
+		if (rev->status == RTE_EPOLL_INVALID)
+			continue;
+		if (rte_epoll_ctl(rev->epfd, EPOLL_CTL_DEL, rev->fd, rev)) {
+			/* force free if the entry valid */
+			eal_epoll_data_safe_free(rev);
+			rev->status = RTE_EPOLL_INVALID;
+		}
+	}
+
+	if (intr_handle->max_intr > intr_handle->nb_efd) {
+		for (i = 0; i < intr_handle->nb_efd; i++)
+			close(intr_handle->efds[i]);
+	}
+	intr_handle->nb_efd = 0;
+	intr_handle->max_intr = 0;
+}
diff --git a/lib/librte_eal/linuxapp/eal/include/exec-env/rte_interrupts.h b/lib/librte_eal/linuxapp/eal/include/exec-env/rte_interrupts.h
index 41753e8..46b1113 100644
--- a/lib/librte_eal/linuxapp/eal/include/exec-env/rte_interrupts.h
+++ b/lib/librte_eal/linuxapp/eal/include/exec-env/rte_interrupts.h
@@ -168,4 +168,55 @@ rte_intr_rx_ctl(struct rte_intr_handle *intr_handle,
 		int epfd, int op, unsigned int vec,
 		void *data, int socket);
 
+/**
+ * It enables the fastpath event fds if it's necessary.
+ * It creates event fds when multi-vectors allowed,
+ * otherwise it multiplexes the single event fds.
+ *
+ * @param intr_handle
+ *   Pointer to the interrupt handle.
+ * @param nb_vec
+ *   Number of intrrupt vector trying to enable.
+ * @return
+ *   - On success, zero.
+ *   - On failure, a negative value.
+ */
+int
+rte_intr_efd_enable(struct rte_intr_handle *intr_handle, uint32_t nb_efd);
+
+/**
+ * It disable the fastpath event fds.
+ * It deletes registered eventfds and closes the open fds.
+ *
+ * @param intr_handle
+ *   Pointer to the interrupt handle.
+ */
+void
+rte_intr_efd_disable(struct rte_intr_handle *intr_handle);
+
+/**
+ * The fastpath interrupt is enabled or not.
+ *
+ * @param intr_handle
+ *   Pointer to the interrupt handle.
+ */
+static inline int
+rte_intr_dp_is_en(struct rte_intr_handle *intr_handle)
+{
+	return !(!intr_handle->nb_efd);
+}
+
+/**
+ * The interrupt handle instance allows other cause or not.
+ * Other cause stands for none fastpath interrupt.
+ *
+ * @param intr_handle
+ *   Pointer to the interrupt handle.
+ */
+static inline int
+rte_intr_allow_others(struct rte_intr_handle *intr_handle)
+{
+	return !!(intr_handle->max_intr - intr_handle->nb_efd);
+}
+
 #endif /* _RTE_LINUXAPP_INTERRUPTS_H_ */
diff --git a/lib/librte_eal/linuxapp/eal/rte_eal_version.map b/lib/librte_eal/linuxapp/eal/rte_eal_version.map
index 65b5ed2..d0df6b4 100644
--- a/lib/librte_eal/linuxapp/eal/rte_eal_version.map
+++ b/lib/librte_eal/linuxapp/eal/rte_eal_version.map
@@ -61,7 +61,11 @@ DPDK_2.0 {
 	rte_hexdump;
 	rte_intr_callback_register;
 	rte_intr_callback_unregister;
+	rte_intr_allow_others;
 	rte_intr_disable;
+	rte_intr_dp_is_en;
+	rte_intr_efd_enable;
+	rte_intr_efd_disable;
 	rte_intr_enable;
 	rte_intr_rx_ctl;
 	rte_intr_tls_epfd;
-- 
1.8.1.4



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