[dpdk-dev] [PATCH v12 06/14] eal/linux: standalone intr event fd create support

Cunming Liang cunming.liang at intel.com
Mon Jun 8 07:29:03 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 functions 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>
---
v11 changes
 - typo cleanup

 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 d35c874..5519e7c 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 */
 
@@ -1110,3 +1112,58 @@ 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 3e93a27..912cc50 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
@@ -166,4 +166,55 @@ int
 rte_intr_rx_ctl(struct rte_intr_handle *intr_handle,
 		int epfd, int op, unsigned int vec, void *data);
 
+/**
+ * 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 interrupt 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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