[dpdk-dev] [RFC 1/7] eal: interrupt handle API prototypes

[Harman Kalra <hkalra@marvell.com>]

Defining protypes of get/set APIs for accessing/manipulating
interrupt handle fields.

Internal interrupt header i.e. rte_eal_interrupt.h is rearranged,
as APIs defined are moved to rte_interrupts.h and epoll specific
definitions are moved to a new header rte_epoll.h.
Later in the series rte_eal_interrupt.h will be removed.

Signed-off-by: Harman Kalra <hkalra@marvell.com>
---
 MAINTAINERS                          |   1 +
 lib/eal/include/meson.build          |   1 +
 lib/eal/include/rte_eal_interrupts.h | 201 ---------
 lib/eal/include/rte_epoll.h          | 116 +++++
 lib/eal/include/rte_interrupts.h     | 653 ++++++++++++++++++++++++++-
 5 files changed, 769 insertions(+), 203 deletions(-)
 create mode 100644 lib/eal/include/rte_epoll.h

diff --git a/MAINTAINERS b/MAINTAINERS
index 266f5ac1da..53b092f532 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -208,6 +208,7 @@ F: app/test/test_memzone.c
 
 Interrupt Subsystem
 M: Harman Kalra <hkalra@marvell.com>
+F: lib/eal/include/rte_epoll.h
 F: lib/eal/*/*interrupts.*
 F: app/test/test_interrupts.c
 
diff --git a/lib/eal/include/meson.build b/lib/eal/include/meson.build
index 88a9eba12f..8e258607b8 100644
--- a/lib/eal/include/meson.build
+++ b/lib/eal/include/meson.build
@@ -19,6 +19,7 @@ headers += files(
         'rte_eal_memconfig.h',
         'rte_eal_trace.h',
         'rte_errno.h',
+        'rte_epoll.h',
         'rte_fbarray.h',
         'rte_hexdump.h',
         'rte_hypervisor.h',
diff --git a/lib/eal/include/rte_eal_interrupts.h b/lib/eal/include/rte_eal_interrupts.h
index 00bcc19b6d..68ca3a042d 100644
--- a/lib/eal/include/rte_eal_interrupts.h
+++ b/lib/eal/include/rte_eal_interrupts.h
@@ -39,32 +39,6 @@ enum rte_intr_handle_type {
 	RTE_INTR_HANDLE_MAX           /**< count of elements */
 };
 
-#define RTE_INTR_EVENT_ADD            1UL
-#define RTE_INTR_EVENT_DEL            2UL
-
-typedef void (*rte_intr_event_cb_t)(int fd, void *arg);
-
-struct rte_epoll_data {
-	uint32_t event;               /**< event type */
-	void *data;                   /**< User data */
-	rte_intr_event_cb_t cb_fun;   /**< IN: callback fun */
-	void *cb_arg;	              /**< IN: callback arg */
-};
-
-enum {
-	RTE_EPOLL_INVALID = 0,
-	RTE_EPOLL_VALID,
-	RTE_EPOLL_EXEC,
-};
-
-/** interrupt epoll event obj, taken by epoll_event.ptr */
-struct rte_epoll_event {
-	uint32_t status;           /**< OUT: event status */
-	int fd;                    /**< OUT: event fd */
-	int epfd;       /**< OUT: epoll instance the ev associated with */
-	struct rte_epoll_data epdata;
-};
-
 /** Handle for interrupts. */
 struct rte_intr_handle {
 	RTE_STD_C11
@@ -91,179 +65,4 @@ struct rte_intr_handle {
 	int *intr_vec;                 /**< intr vector number array */
 };
 
-#define RTE_EPOLL_PER_THREAD        -1  /**< to hint using per thread epfd */
-
-/**
- * It waits for events on the epoll instance.
- * Retries if signal received.
- *
- * @param epfd
- *   Epoll instance fd on which the caller wait for events.
- * @param events
- *   Memory area contains the events that will be available for the caller.
- * @param maxevents
- *   Up to maxevents are returned, must greater than zero.
- * @param timeout
- *   Specifying a timeout of -1 causes a block indefinitely.
- *   Specifying a timeout equal to zero cause to return immediately.
- * @return
- *   - On success, returns the number of available event.
- *   - On failure, a negative value.
- */
-int
-rte_epoll_wait(int epfd, struct rte_epoll_event *events,
-	       int maxevents, int timeout);
-
-/**
- * It waits for events on the epoll instance.
- * Does not retry if signal received.
- *
- * @param epfd
- *   Epoll instance fd on which the caller wait for events.
- * @param events
- *   Memory area contains the events that will be available for the caller.
- * @param maxevents
- *   Up to maxevents are returned, must greater than zero.
- * @param timeout
- *   Specifying a timeout of -1 causes a block indefinitely.
- *   Specifying a timeout equal to zero cause to return immediately.
- * @return
- *   - On success, returns the number of available event.
- *   - On failure, a negative value.
- */
-__rte_experimental
-int
-rte_epoll_wait_interruptible(int epfd, struct rte_epoll_event *events,
-	       int maxevents, int timeout);
-
-/**
- * It performs control operations on epoll instance referred by the epfd.
- * It requests that the operation op be performed for the target fd.
- *
- * @param epfd
- *   Epoll instance fd on which the caller perform control operations.
- * @param op
- *   The operation be performed for the target fd.
- * @param fd
- *   The target fd on which the control ops perform.
- * @param event
- *   Describes the object linked to the fd.
- *   Note: The caller must take care the object deletion after CTL_DEL.
- * @return
- *   - On success, zero.
- *   - On failure, a negative value.
- */
-int
-rte_epoll_ctl(int epfd, int op, int fd,
-	      struct rte_epoll_event *event);
-
-/**
- * The function returns the per thread epoll instance.
- *
- * @return
- *   epfd the epoll instance referred to.
- */
-int
-rte_intr_tls_epfd(void);
-
-/**
- * @param intr_handle
- *   Pointer to the interrupt handle.
- * @param epfd
- *   Epoll instance fd which the intr vector associated to.
- * @param op
- *   The operation be performed for the vector.
- *   Operation type of {ADD, DEL}.
- * @param vec
- *   RX intr vector number added to the epoll instance wait list.
- * @param data
- *   User raw data.
- * @return
- *   - On success, zero.
- *   - On failure, a negative value.
- */
-int
-rte_intr_rx_ctl(struct rte_intr_handle *intr_handle,
-		int epfd, int op, unsigned int vec, void *data);
-
-/**
- * It deletes registered eventfds.
- *
- * @param intr_handle
- *   Pointer to the interrupt handle.
- */
-void
-rte_intr_free_epoll_fd(struct rte_intr_handle *intr_handle);
-
-/**
- * It enables the packet I/O interrupt event if it's necessary.
- * It creates event fd for each interrupt vector when MSIX is used,
- * otherwise it multiplexes a single event fd.
- *
- * @param intr_handle
- *   Pointer to the interrupt handle.
- * @param nb_efd
- *   Number of interrupt vector trying to enable.
- *   The value 0 is not allowed.
- * @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 disables the packet I/O interrupt event.
- * 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 packet I/O interrupt on datapath is enabled or not.
- *
- * @param intr_handle
- *   Pointer to the interrupt handle.
- */
-int
-rte_intr_dp_is_en(struct rte_intr_handle *intr_handle);
-
-/**
- * The interrupt handle instance allows other causes or not.
- * Other causes stand for any none packet I/O interrupts.
- *
- * @param intr_handle
- *   Pointer to the interrupt handle.
- */
-int
-rte_intr_allow_others(struct rte_intr_handle *intr_handle);
-
-/**
- * The multiple interrupt vector capability of interrupt handle instance.
- * It returns zero if no multiple interrupt vector support.
- *
- * @param intr_handle
- *   Pointer to the interrupt handle.
- */
-int
-rte_intr_cap_multiple(struct rte_intr_handle *intr_handle);
-
-/**
- * @warning
- * @b EXPERIMENTAL: this API may change without prior notice
- *
- * @internal
- * Check if currently executing in interrupt context
- *
- * @return
- *  - non zero in case of interrupt context
- *  - zero in case of process context
- */
-__rte_experimental
-int
-rte_thread_is_intr(void);
-
 #endif /* _RTE_EAL_INTERRUPTS_H_ */
diff --git a/lib/eal/include/rte_epoll.h b/lib/eal/include/rte_epoll.h
new file mode 100644
index 0000000000..182353cfd4
--- /dev/null
+++ b/lib/eal/include/rte_epoll.h
@@ -0,0 +1,116 @@
+/* SPDX-License-Identifier: BSD-3-Clause
+ * Copyright(C) 2021 Marvell International Ltd.
+ */
+
+#ifndef __RTE_EPOLL_H__
+#define __RTE_EPOLL_H__
+
+/**
+ * @file
+ * The rte_epoll provides interfaces functions to add delete events,
+ * wait poll for an event.
+ */
+
+#include <rte_compat.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#define RTE_INTR_EVENT_ADD            1UL
+#define RTE_INTR_EVENT_DEL            2UL
+
+typedef void (*rte_intr_event_cb_t)(int fd, void *arg);
+
+struct rte_epoll_data {
+	uint32_t event;               /**< event type */
+	void *data;                   /**< User data */
+	rte_intr_event_cb_t cb_fun;   /**< IN: callback fun */
+	void *cb_arg;	              /**< IN: callback arg */
+};
+
+enum {
+	RTE_EPOLL_INVALID = 0,
+	RTE_EPOLL_VALID,
+	RTE_EPOLL_EXEC,
+};
+
+/** interrupt epoll event obj, taken by epoll_event.ptr */
+struct rte_epoll_event {
+	uint32_t status;           /**< OUT: event status */
+	int fd;                    /**< OUT: event fd */
+	int epfd;       /**< OUT: epoll instance the ev associated with */
+	struct rte_epoll_data epdata;
+};
+
+#define RTE_EPOLL_PER_THREAD        -1  /**< to hint using per thread epfd */
+
+/**
+ * It waits for events on the epoll instance.
+ * Retries if signal received.
+ *
+ * @param epfd
+ *   Epoll instance fd on which the caller wait for events.
+ * @param events
+ *   Memory area contains the events that will be available for the caller.
+ * @param maxevents
+ *   Up to maxevents are returned, must greater than zero.
+ * @param timeout
+ *   Specifying a timeout of -1 causes a block indefinitely.
+ *   Specifying a timeout equal to zero cause to return immediately.
+ * @return
+ *   - On success, returns the number of available event.
+ *   - On failure, a negative value.
+ */
+int
+rte_epoll_wait(int epfd, struct rte_epoll_event *events,
+	       int maxevents, int timeout);
+
+/**
+ * It waits for events on the epoll instance.
+ * Does not retry if signal received.
+ *
+ * @param epfd
+ *   Epoll instance fd on which the caller wait for events.
+ * @param events
+ *   Memory area contains the events that will be available for the caller.
+ * @param maxevents
+ *   Up to maxevents are returned, must greater than zero.
+ * @param timeout
+ *   Specifying a timeout of -1 causes a block indefinitely.
+ *   Specifying a timeout equal to zero cause to return immediately.
+ * @return
+ *   - On success, returns the number of available event.
+ *   - On failure, a negative value.
+ */
+__rte_experimental
+int
+rte_epoll_wait_interruptible(int epfd, struct rte_epoll_event *events,
+	       int maxevents, int timeout);
+
+/**
+ * It performs control operations on epoll instance referred by the epfd.
+ * It requests that the operation op be performed for the target fd.
+ *
+ * @param epfd
+ *   Epoll instance fd on which the caller perform control operations.
+ * @param op
+ *   The operation be performed for the target fd.
+ * @param fd
+ *   The target fd on which the control ops perform.
+ * @param event
+ *   Describes the object linked to the fd.
+ *   Note: The caller must take care the object deletion after CTL_DEL.
+ * @return
+ *   - On success, zero.
+ *   - On failure, a negative value.
+ */
+int
+rte_epoll_ctl(int epfd, int op, int fd,
+	      struct rte_epoll_event *event);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* __RTE_EPOLL_H__ */
diff --git a/lib/eal/include/rte_interrupts.h b/lib/eal/include/rte_interrupts.h
index cc3bf45d8c..afc3262967 100644
--- a/lib/eal/include/rte_interrupts.h
+++ b/lib/eal/include/rte_interrupts.h
@@ -5,8 +5,11 @@
 #ifndef _RTE_INTERRUPTS_H_
 #define _RTE_INTERRUPTS_H_
 
+#include <stdbool.h>
+
 #include <rte_common.h>
 #include <rte_compat.h>
+#include <rte_epoll.h>
 
 /**
  * @file
@@ -22,6 +25,10 @@ extern "C" {
 /** Interrupt handle */
 struct rte_intr_handle;
 
+#define RTE_INTR_HANDLE_DEFAULT_SIZE  1
+
+#include "rte_eal_interrupts.h"
+
 /** Function to be registered for the specific interrupt */
 typedef void (*rte_intr_callback_fn)(void *cb_arg);
 
@@ -32,8 +39,6 @@ typedef void (*rte_intr_callback_fn)(void *cb_arg);
 typedef void (*rte_intr_unregister_callback_fn)(struct rte_intr_handle *intr_handle,
 						void *cb_arg);
 
-#include "rte_eal_interrupts.h"
-
 /**
  * It registers the callback for the specific interrupt. Multiple
  * callbacks can be registered at the same time.
@@ -163,6 +168,650 @@ int rte_intr_disable(const struct rte_intr_handle *intr_handle);
 __rte_experimental
 int rte_intr_ack(const struct rte_intr_handle *intr_handle);
 
+/**
+ * The function returns the per thread epoll instance.
+ *
+ * @return
+ *   epfd the epoll instance referred to.
+ */
+int
+rte_intr_tls_epfd(void);
+
+/**
+ * @param intr_handle
+ *   Pointer to the interrupt handle.
+ * @param epfd
+ *   Epoll instance fd which the intr vector associated to.
+ * @param op
+ *   The operation be performed for the vector.
+ *   Operation type of {ADD, DEL}.
+ * @param vec
+ *   RX intr vector number added to the epoll instance wait list.
+ * @param data
+ *   User raw data.
+ * @return
+ *   - On success, zero.
+ *   - On failure, a negative value.
+ */
+int
+rte_intr_rx_ctl(struct rte_intr_handle *intr_handle,
+		int epfd, int op, unsigned int vec, void *data);
+
+/**
+ * It deletes registered eventfds.
+ *
+ * @param intr_handle
+ *   Pointer to the interrupt handle.
+ */
+void
+rte_intr_free_epoll_fd(struct rte_intr_handle *intr_handle);
+
+/**
+ * It enables the packet I/O interrupt event if it's necessary.
+ * It creates event fd for each interrupt vector when MSIX is used,
+ * otherwise it multiplexes a single event fd.
+ *
+ * @param intr_handle
+ *   Pointer to the interrupt handle.
+ * @param nb_efd
+ *   Number of interrupt vector trying to enable.
+ *   The value 0 is not allowed.
+ * @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 disables the packet I/O interrupt event.
+ * 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 packet I/O interrupt on datapath is enabled or not.
+ *
+ * @param intr_handle
+ *   Pointer to the interrupt handle.
+ */
+int
+rte_intr_dp_is_en(struct rte_intr_handle *intr_handle);
+
+/**
+ * The interrupt handle instance allows other causes or not.
+ * Other causes stand for any none packet I/O interrupts.
+ *
+ * @param intr_handle
+ *   Pointer to the interrupt handle.
+ */
+int
+rte_intr_allow_others(struct rte_intr_handle *intr_handle);
+
+/**
+ * The multiple interrupt vector capability of interrupt handle instance.
+ * It returns zero if no multiple interrupt vector support.
+ *
+ * @param intr_handle
+ *   Pointer to the interrupt handle.
+ */
+int
+rte_intr_cap_multiple(struct rte_intr_handle *intr_handle);
+
+/**
+ * @warning
+ * @b EXPERIMENTAL: this API may change without prior notice
+ *
+ * @internal
+ * Check if currently executing in interrupt context
+ *
+ * @return
+ *  - non zero in case of interrupt context
+ *  - zero in case of process context
+ */
+__rte_experimental
+int
+rte_thread_is_intr(void);
+
+/**
+ * @warning
+ * @b EXPERIMENTAL: this API may change without prior notice
+ *
+ * It allocates memory for interrupt instances based on size provided by user
+ * i.e. whether a single handle or array of handles is defined by size. Memory
+ * to be allocated from a hugepage or normal allocation is also defined by user.
+ * Default memory allocation for event fds and event list array is done which
+ * can be realloced later as per the requirement.
+ *
+ * This function should be called from application or driver, before calling any
+ * of the interrupt APIs.
+ *
+ * @param size
+ *  No of interrupt instances.
+ * @param from_hugepage
+ *  Memory allocation from hugepage or normal allocation
+ *
+ * @return
+ *  - On success, address of first interrupt handle.
+ *  - On failure, NULL.
+ */
+__rte_experimental
+struct rte_intr_handle *rte_intr_handle_instance_alloc(int size,
+						       bool from_hugepage);
+
+/**
+ * @warning
+ * @b EXPERIMENTAL: this API may change without prior notice
+ *
+ * Returns the address of interrupt handle instance as per the index
+ * provided.
+ *
+ * @param intr_handle
+ *  Base address of interrupt handle array.
+ * @param index
+ *  Index of the interrupt handle
+ *
+ * @return
+ *  - On success, address of interrupt handle at index
+ *  - On failure, NULL.
+ */
+__rte_experimental
+struct rte_intr_handle *rte_intr_handle_instance_index_get(
+			struct rte_intr_handle *intr_handle, int index);
+
+/**
+ * @warning
+ * @b EXPERIMENTAL: this API may change without prior notice
+ *
+ * This API is used to free the memory allocated for event fds. event lists
+ * and interrupt handle array.
+ *
+ * @param intr_handle
+ *  Base address of interrupt handle array.
+ *
+ */
+__rte_experimental
+void rte_intr_handle_instance_free(struct rte_intr_handle *intr_handle);
+
+/**
+ * @warning
+ * @b EXPERIMENTAL: this API may change without prior notice
+ *
+ * This API is used to populate interrupt handle at a given index of array
+ * of interrupt handles, with the values defined in src handler.
+ *
+ * @param intr_handle
+ *  Start address of interrupt handles
+ * @param
+ *  Source interrupt handle to be cloned.
+ * @param index
+ *  Index of the interrupt handle
+ *
+ * @return
+ *   - On success, zero.
+ *   - On failure, a negative value.
+ */
+__rte_experimental
+int rte_intr_handle_instance_index_set(struct rte_intr_handle *intr_handle,
+				   const struct rte_intr_handle *src,
+				   int index);
+/**
+ * @warning
+ * @b EXPERIMENTAL: this API may change without prior notice
+ *
+ * This API is used to set the fd field of interrupt handle with user provided
+ * file descriptor.
+ *
+ * @param intr_handle
+ *  pointer to the interrupt handle.
+ * @param fd
+ *  file descriptor value provided by user.
+ *
+ * @return
+ *  - On success, zero.
+ *  - On failure, a negative value.
+ */
+__rte_experimental
+int rte_intr_handle_fd_set(struct rte_intr_handle *intr_handle, int fd);
+
+/**
+ * @warning
+ * @b EXPERIMENTAL: this API may change without prior notice
+ *
+ * Returns the fd field of the given interrupt handle instance.
+ *
+ * @param intr_handle
+ *  pointer to the interrupt handle.
+ *
+ * @return
+ *  - On success, fd field.
+ *  - On failure, a negative value.
+ */
+__rte_experimental
+int rte_intr_handle_fd_get(const struct rte_intr_handle *intr_handle);
+
+/**
+ * @warning
+ * @b EXPERIMENTAL: this API may change without prior notice
+ *
+ * This API is used to set the type field of interrupt handle with user provided
+ * interrupt type.
+ *
+ * @param intr_handle
+ *  pointer to the interrupt handle.
+ * @param type
+ *  interrupt type
+ *
+ * @return
+ *  - On success, zero.
+ *  - On failure, a negative value.
+ */
+__rte_experimental
+int rte_intr_handle_type_set(struct rte_intr_handle *intr_handle,
+			     enum rte_intr_handle_type type);
+
+/**
+ * @warning
+ * @b EXPERIMENTAL: this API may change without prior notice
+ *
+ * Returns the type field of the given interrupt handle instance.
+ *
+ * @param intr_handle
+ *  pointer to the interrupt handle.
+ *
+ * @return
+ *  - On success, interrupt type
+ *  - On failure, RTE_INTR_HANDLE_UNKNOWN.
+ */
+__rte_experimental
+enum rte_intr_handle_type rte_intr_handle_type_get(
+				const struct rte_intr_handle *intr_handle);
+
+/**
+ * @warning
+ * @b EXPERIMENTAL: this API may change without prior notice
+ *
+ * This API is used to set the device fd field of interrupt handle with user
+ * provided dev fd. Device fd corresponds to VFIO device fd or UIO config fd.
+ *
+ * @param intr_handle
+ *  pointer to the interrupt handle.
+ * @param fd
+ *  interrupt type
+ *
+ * @return
+ *  - On success, zero.
+ *  - On failure, a negative value.
+ */
+__rte_experimental
+int rte_intr_handle_dev_fd_set(struct rte_intr_handle *intr_handle, int fd);
+
+/**
+ * @warning
+ * @b EXPERIMENTAL: this API may change without prior notice
+ *
+ * Returns the device fd field of the given interrupt handle instance.
+ *
+ * @param intr_handle
+ *  pointer to the interrupt handle.
+ *
+ * @return
+ *  - On success, dev fd.
+ *  - On failure, a negative value.
+ */
+__rte_experimental
+int rte_intr_handle_dev_fd_get(const struct rte_intr_handle *intr_handle);
+
+/**
+ * @warning
+ * @b EXPERIMENTAL: this API may change without prior notice
+ *
+ * This API is used to set the max intr field of interrupt handle with user
+ * provided max intr value.
+ *
+ * @param intr_handle
+ *  pointer to the interrupt handle.
+ * @param max_intr
+ *  interrupt type
+ *
+ * @return
+ *  - On success, zero.
+ *  - On failure, a negative value.
+ */
+__rte_experimental
+int rte_intr_handle_max_intr_set(struct rte_intr_handle *intr_handle,
+				 int max_intr);
+
+/**
+ * @warning
+ * @b EXPERIMENTAL: this API may change without prior notice
+ *
+ * Returns the max intr field of the given interrupt handle instance.
+ *
+ * @param intr_handle
+ *  pointer to the interrupt handle.
+ *
+ * @return
+ *  - On success, max intr.
+ *  - On failure, a negative value.
+ */
+__rte_experimental
+int rte_intr_handle_max_intr_get(const struct rte_intr_handle *intr_handle);
+
+/**
+ * @warning
+ * @b EXPERIMENTAL: this API may change without prior notice
+ *
+ * This API is used to set the no of event fd field of interrupt handle with
+ * user provided available event file descriptor value.
+ *
+ * @param intr_handle
+ *  pointer to the interrupt handle.
+ * @param nb_efd
+ *  Available event fd
+ *
+ * @return
+ *  - On success, zero.
+ *  - On failure, a negative value.
+ */
+__rte_experimental
+int rte_intr_handle_nb_efd_set(struct rte_intr_handle *intr_handle, int nb_efd);
+
+/**
+ * @warning
+ * @b EXPERIMENTAL: this API may change without prior notice
+ *
+ * Returns the no of available event fd field of the given interrupt handle
+ * instance.
+ *
+ * @param intr_handle
+ *  pointer to the interrupt handle.
+ *
+ * @return
+ *  - On success, nb_efd
+ *  - On failure, a negative value.
+ */
+__rte_experimental
+int rte_intr_handle_nb_efd_get(const struct rte_intr_handle *intr_handle);
+
+/**
+ * @warning
+ * @b EXPERIMENTAL: this API may change without prior notice
+ *
+ * Returns the no of interrupt vector field of the given interrupt handle
+ * instance. This field is to configured on device probe time, and based on
+ * this value efds and elist arrays are dynamically allocated. By default
+ * this value is set to RTE_MAX_RXTX_INTR_VEC_ID.
+ * For eg. in case of PCI device, its msix size is queried and efds/elist
+ * arrays are allocated accordingly.
+ *
+ * @param intr_handle
+ *  pointer to the interrupt handle.
+ *
+ * @return
+ *  - On success, nb_intr
+ *  - On failure, a negative value.
+ */
+__rte_experimental
+int rte_intr_handle_nb_intr_get(const struct rte_intr_handle *intr_handle);
+
+/**
+ * @warning
+ * @b EXPERIMENTAL: this API may change without prior notice
+ *
+ * This API is used to set the event fd counter size field of interrupt handle
+ * with user provided efd counter size.
+ *
+ * @param intr_handle
+ *  pointer to the interrupt handle.
+ * @param efd_counter_size
+ *  size of efd counter, used for vdev
+ *
+ * @return
+ *  - On success, zero.
+ *  - On failure, a negative value.
+ */
+__rte_experimental
+int rte_intr_handle_efd_counter_size_set(struct rte_intr_handle *intr_handle,
+					 uint8_t efd_counter_size);
+
+/**
+ * @warning
+ * @b EXPERIMENTAL: this API may change without prior notice
+ *
+ * Returns the event fd counter size field of the given interrupt handle
+ * instance.
+ *
+ * @param intr_handle
+ *  pointer to the interrupt handle.
+ *
+ * @return
+ *  - On success, efd_counter_size
+ *  - On failure, a negative value.
+ */
+__rte_experimental
+int rte_intr_handle_efd_counter_size_get(
+				const struct rte_intr_handle *intr_handle);
+
+/**
+ * @warning
+ * @b EXPERIMENTAL: this API may change without prior notice
+ *
+ * Returns the base address of the event fds array field of given interrupt
+ * handle.
+ *
+ * @param intr_handle
+ *  pointer to the interrupt handle.
+ *
+ * @return
+ *  - On success, efds base address
+ *  - On failure, a negative value.
+ */
+__rte_experimental
+int *rte_intr_handle_efds_base(struct rte_intr_handle *intr_handle);
+
+/**
+ * @warning
+ * @b EXPERIMENTAL: this API may change without prior notice
+ *
+ * This API is used to set the event fd array index with the given fd.
+ *
+ * @param intr_handle
+ *  pointer to the interrupt handle.
+ * @param index
+ *  efds array index to be set
+ * @param fd
+ *  event fd
+ *
+ * @return
+ *  - On success, zero.
+ *  - On failure, a negative value.
+ */
+__rte_experimental
+int rte_intr_handle_efds_index_set(struct rte_intr_handle *intr_handle,
+				   int index, int fd);
+
+/**
+ * @warning
+ * @b EXPERIMENTAL: this API may change without prior notice
+ *
+ * Returns the fd value of event fds array at a given index.
+ *
+ * @param intr_handle
+ *  pointer to the interrupt handle.
+ * @param index
+ *  efds array index to be returned
+ *
+ * @return
+ *  - On success, fd
+ *  - On failure, a negative value.
+ */
+__rte_experimental
+int rte_intr_handle_efds_index_get(const struct rte_intr_handle *intr_handle,
+				   int index);
+/**
+ * @warning
+ * @b EXPERIMENTAL: this API may change without prior notice
+ *
+ * This API is used to set the event list array index with the given elist
+ * instance.
+ *
+ * @param intr_handle
+ *  pointer to the interrupt handle.
+ * @param index
+ *  elist array index to be set
+ * @param elist
+ *  event list instance of struct rte_epoll_event
+ *
+ * @return
+ *  - On success, zero.
+ *  - On failure, a negative value.
+ */
+__rte_experimental
+int rte_intr_handle_elist_index_set(struct rte_intr_handle *intr_handle,
+				   int index, struct rte_epoll_event elist);
+
+/**
+ * @warning
+ * @b EXPERIMENTAL: this API may change without prior notice
+ *
+ * Returns the address of elist instance of event list array at a given index.
+ *
+ * @param intr_handle
+ *  pointer to the interrupt handle.
+ * @param index
+ *  elist array index to be returned
+ *
+ * @return
+ *  - On success, elist
+ *  - On failure, a negative value.
+ */
+__rte_experimental
+struct rte_epoll_event *rte_intr_handle_elist_index_get(
+				struct rte_intr_handle *intr_handle, int index);
+
+/**
+ * @warning
+ * @b EXPERIMENTAL: this API may change without prior notice
+ *
+ * Allocates the memory of interrupt vector list array, with size defining the
+ * no of elements required in the array.
+ *
+ * @param intr_handle
+ *  pointer to the interrupt handle.
+ * @param name
+ *  Name assigned to the allocation, or NULL.
+ * @param size
+ * No of element required in the array.
+ *
+ * @return
+ *  - On success, zero
+ *  - On failure, a negative value.
+ */
+__rte_experimental
+int rte_intr_handle_vec_list_alloc(struct rte_intr_handle *intr_handle,
+				   const char *name, int size);
+
+/**
+ * @warning
+ * @b EXPERIMENTAL: this API may change without prior notice
+ *
+ * Sets the vector value at given index of interrupt vector list field of given
+ * interrupt handle.
+ *
+ * @param intr_handle
+ *  pointer to the interrupt handle.
+ * @param index
+ *  intr_vec array index to be set
+ * @param vec
+ *  Interrupt vector value.
+ *
+ * @return
+ *  - On success, zero
+ *  - On failure, a negative value.
+ */
+__rte_experimental
+int rte_intr_handle_vec_list_index_set(struct rte_intr_handle *intr_handle,
+				       int index, int vec);
+
+/**
+ * @warning
+ * @b EXPERIMENTAL: this API may change without prior notice
+ *
+ * Returns the vector value at the given index of interrupt vector list array.
+ *
+ * @param intr_handle
+ *  pointer to the interrupt handle.
+ * @param index
+ *  intr_vec array index to be returned
+ *
+ * @return
+ *  - On success, interrupt vector
+ *  - On failure, a negative value.
+ */
+__rte_experimental
+int rte_intr_handle_vec_list_index_get(
+			const struct rte_intr_handle *intr_handle, int index);
+
+/**
+ * @warning
+ * @b EXPERIMENTAL: this API may change without prior notice
+ *
+ * Freeing the memory allocated for interrupt vector list array.
+ *
+ * @param intr_handle
+ *  pointer to the interrupt handle.
+ *
+ * @return
+ *  - On success, zero
+ *  - On failure, a negative value.
+ */
+__rte_experimental
+void rte_intr_handle_vec_list_free(struct rte_intr_handle *intr_handle);
+
+/**
+ * @warning
+ * @b EXPERIMENTAL: this API may change without prior notice
+ *
+ * Returns the base address of interrupt vector list array.
+ *
+ * @param intr_handle
+ *  pointer to the interrupt handle.
+ *
+ * @return
+ *  - On success, base address of intr_vec array
+ *  - On failure, a negative value.
+ */
+__rte_experimental
+int *rte_intr_handle_vec_list_base(const struct rte_intr_handle *intr_handle);
+
+/**
+ * @warning
+ * @b EXPERIMENTAL: this API may change without prior notice
+ *
+ * Reallocates the size efds and elist array based on size provided by user.
+ * By default efds and elist array are allocated with default size
+ * RTE_MAX_RXTX_INTR_VEC_ID on interrupt handle array creation. Later on device
+ * probe, device may have capability of more interrupts than
+ * RTE_MAX_RXTX_INTR_VEC_ID. Hence using this API, PMDs can reallocate the
+ * arrays as per the max interrupts capability of device.
+ *
+ * @param intr_handle
+ *  pointer to the interrupt handle.
+ * @param size
+ *  efds and elist array size.
+ *
+ * @return
+ *  - On success, zero
+ *  - On failure, a negative value.
+ */
+__rte_experimental
+int rte_intr_handle_event_list_update(struct rte_intr_handle *intr_handle,
+				      int size);
 #ifdef __cplusplus
 }
 #endif
-- 
2.18.0