eal: add synchronous interrupt unregister

Avoid race with unregister interrupt handler if interrupt
source has some active callbacks at the moment, use wrapper
around rte_intr_callback_unregister() to check for -EAGAIN
return value and to loop until rte_intr_callback_unregister()
succeeds.

Signed-off-by: Renata Saiakhova <renata.saiakhova@ekinops.com>
Acked-by: Anatoly Burakov <anatoly.burakov@intel.com>
Acked-by: Harman Kalra <hkalra@marvell.com>

diff --git a/drivers/bus/pci/linux/pci_vfio.c b/drivers/bus/pci/linux/pci_vfio.c
index 9d689d6..d3a59a1 100644 (file)
--- a/drivers/bus/pci/linux/pci_vfio.c
+++ b/drivers/bus/pci/linux/pci_vfio.c
@@ -409,7 +409,7 @@ pci_vfio_disable_notifier(struct rte_pci_device *dev)
                return -1;
        }
 
-       ret = rte_intr_callback_unregister(&dev->vfio_req_intr_handle,
+       ret = rte_intr_callback_unregister_sync(&dev->vfio_req_intr_handle,
                                           pci_vfio_req_handler,
                                           (void *)&dev->device);
        if (ret < 0) {

diff --git a/lib/librte_eal/freebsd/eal_interrupts.c b/lib/librte_eal/freebsd/eal_interrupts.c
index 72eeacb..8681084 100644 (file)
--- a/lib/librte_eal/freebsd/eal_interrupts.c
+++ b/lib/librte_eal/freebsd/eal_interrupts.c
@@ -345,6 +345,18 @@ out:
        return ret;
 }
 
+int
+rte_intr_callback_unregister_sync(const struct rte_intr_handle *intr_handle,
+               rte_intr_callback_fn cb_fn, void *cb_arg)
+{
+       int ret = 0;
+
+       while ((ret = rte_intr_callback_unregister(intr_handle, cb_fn, cb_arg)) == -EAGAIN)
+               rte_pause();
+
+       return ret;
+}
+
 int
 rte_intr_enable(const struct rte_intr_handle *intr_handle)
 {

diff --git a/lib/librte_eal/include/rte_interrupts.h b/lib/librte_eal/include/rte_interrupts.h
index e3b406a..cc3bf45 100644 (file)
--- a/lib/librte_eal/include/rte_interrupts.h
+++ b/lib/librte_eal/include/rte_interrupts.h
@@ -94,6 +94,31 @@ rte_intr_callback_unregister_pending(const struct rte_intr_handle *intr_handle,
                                rte_intr_callback_fn cb_fn, void *cb_arg,
                                rte_intr_unregister_callback_fn ucb_fn);
 
+/**
+ * @warning
+ * @b EXPERIMENTAL: this API may change without prior notice
+ *
+ * Loop until rte_intr_callback_unregister() succeeds.
+ * After a call to this function,
+ * the callback provided by the specified interrupt handle is unregistered.
+ *
+ * @param intr_handle
+ *  pointer to the interrupt handle.
+ * @param cb
+ *  callback address.
+ * @param cb_arg
+ *  address of parameter for callback, (void *)-1 means to remove all
+ *  registered which has the same callback address.
+ *
+ * @return
+ *  - On success, return the number of callback entities removed.
+ *  - On failure, a negative value.
+ */
+__rte_experimental
+int
+rte_intr_callback_unregister_sync(const struct rte_intr_handle *intr_handle,
+                               rte_intr_callback_fn cb, void *cb_arg);
+
 /**
  * It enables the interrupt for the specified handle.
  *

diff --git a/lib/librte_eal/linux/eal_interrupts.c b/lib/librte_eal/linux/eal_interrupts.c
index 1dd994b..22b3b7b 100644 (file)
--- a/lib/librte_eal/linux/eal_interrupts.c
+++ b/lib/librte_eal/linux/eal_interrupts.c
@@ -662,6 +662,18 @@ rte_intr_callback_unregister(const struct rte_intr_handle *intr_handle,
        return ret;
 }
 
+int
+rte_intr_callback_unregister_sync(const struct rte_intr_handle *intr_handle,
+                       rte_intr_callback_fn cb_fn, void *cb_arg)
+{
+       int ret = 0;
+
+       while ((ret = rte_intr_callback_unregister(intr_handle, cb_fn, cb_arg)) == -EAGAIN)
+               rte_pause();
+
+       return ret;
+}
+
 int
 rte_intr_enable(const struct rte_intr_handle *intr_handle)
 {

diff --git a/lib/librte_eal/rte_eal_exports.def b/lib/librte_eal/rte_eal_exports.def
index c320077..ad426f2 100644 (file)
--- a/lib/librte_eal/rte_eal_exports.def
+++ b/lib/librte_eal/rte_eal_exports.def
@@ -325,6 +325,7 @@ EXPORTS
        rte_vect_get_max_simd_bitwidth
        rte_vect_set_max_simd_bitwidth
 
+       rte_intr_callback_unregister_sync
        rte_thread_key_create
        rte_thread_key_delete
        rte_thread_value_get

diff --git a/lib/librte_eal/version.map b/lib/librte_eal/version.map
index e23745a..fc305c1 100644 (file)
--- a/lib/librte_eal/version.map
+++ b/lib/librte_eal/version.map
@@ -411,6 +411,7 @@ EXPERIMENTAL {
        rte_power_pause;
 
        # added in 21.05
+       rte_intr_callback_unregister_sync;
        rte_thread_key_create;
        rte_thread_key_delete;
        rte_thread_value_get;

diff --git a/lib/librte_eal/windows/eal_interrupts.c b/lib/librte_eal/windows/eal_interrupts.c
index 3b8266d..1d4cf79 100644 (file)
--- a/lib/librte_eal/windows/eal_interrupts.c
+++ b/lib/librte_eal/windows/eal_interrupts.c
@@ -131,6 +131,14 @@ rte_intr_callback_unregister(
        return 0;
 }
 
+int
+rte_intr_callback_unregister_sync(
+       __rte_unused const struct rte_intr_handle *intr_handle,
+       __rte_unused rte_intr_callback_fn cb_fn, __rte_unused void *cb_arg)
+{
+       return 0;
+}
+
 int
 rte_intr_enable(__rte_unused const struct rte_intr_handle *intr_handle)
 {