[27.03 RFC PATCH v1 8/8] net/nbl: track devices with usage counters

[Anatoly Burakov]

Use EAL usage counters to track VFIO device references.

Signed-off-by: Anatoly Burakov <anatoly.bura...@intel.com>
---
 drivers/net/nbl/nbl_common/nbl_userdev.c | 22 ++++++++++++----------
 1 file changed, 12 insertions(+), 10 deletions(-)

diff --git a/drivers/net/nbl/nbl_common/nbl_userdev.c 
b/drivers/net/nbl/nbl_common/nbl_userdev.c
index 295c617d9d..426cffbc0d 100644
--- a/drivers/net/nbl/nbl_common/nbl_userdev.c
+++ b/drivers/net/nbl/nbl_common/nbl_userdev.c
@@ -4,6 +4,8 @@
 
 #include <uapi/linux/vfio.h>
 
+#include <rte_usage_count.h>
+
 #include "nbl_userdev.h"
 #include <dev_vfio.h>
 
@@ -26,7 +28,7 @@ struct nbl_userdev_map_record {
 };
 
 static int nbl_default_container = -1;
-static int nbl_group_count;
+static rte_usage_count_t nbl_group_count;
 
 TAILQ_HEAD(nbl_adapter_list_head, nbl_adapter);
 static struct nbl_adapter_list_head nbl_adapter_list =
@@ -423,7 +425,7 @@ static int nbl_mdev_map_device(struct nbl_adapter *adapter)
        u64 dma_limit = NBL_USERDEV_DMA_LIMIT;
        int ret, container_create = 0, container_set = 0;
        int vfio_group_fd, container = nbl_default_container;
-       bool new_group = false;
+       bool new_group = false, first_group = false;
 
        rte_pci_device_name(&pci_dev->addr, dev_name, RTE_DEV_NAME_MAX_LEN);
        snprintf(pathname, sizeof(pathname),
@@ -481,11 +483,11 @@ static int nbl_mdev_map_device(struct nbl_adapter 
*adapter)
                        goto free_group;
                }
 
-               nbl_group_count++;
+               first_group = rte_usage_count_claim(&nbl_group_count);
                container_set = 1;
                /* set an IOMMU type for container */
 
-               if (container_create || nbl_group_count == 1) {
+               if (container_create || first_group) {
                        if (ioctl(container, VFIO_CHECK_EXTENSION, 
VFIO_TYPE1v2_IOMMU)) {
                                ret = ioctl(container, VFIO_SET_IOMMU, 
VFIO_TYPE1v2_IOMMU);
                                if (ret) {
@@ -548,13 +550,13 @@ static int nbl_mdev_map_device(struct nbl_adapter 
*adapter)
 close_fd:
        close(common->devfd);
 unregister_mem_event:
-       if (container_set && nbl_group_count == 1) {
+       if (first_group) {
                rte_mcfg_mem_read_lock();
                rte_mem_event_callback_unregister(NBL_USERDEV_EVENT_CLB_NAME, 
NULL);
                rte_mcfg_mem_read_unlock();
        }
 free_dma_map:
-       if (container_set && nbl_group_count == 1) {
+       if (first_group) {
                rte_mcfg_mem_read_lock();
                nbl_userdev_dma_free();
                rte_mcfg_mem_read_unlock();
@@ -562,7 +564,7 @@ static int nbl_mdev_map_device(struct nbl_adapter *adapter)
 unset_container:
        if (container_set) {
                ioctl(vfio_group_fd, VFIO_GROUP_UNSET_CONTAINER, &container);
-               nbl_group_count--;
+               rte_usage_count_release(&nbl_group_count);
        }
 free_group:
        if (new_group)
@@ -577,7 +579,7 @@ static int nbl_mdev_unmap_device(struct nbl_adapter 
*adapter)
 {
        struct nbl_common_info *common = &adapter->common;
        int vfio_group_fd, ret;
-       bool last_group_user;
+       bool last_group_user, last_group = false;
 
        rte_mcfg_mem_read_lock();
        TAILQ_REMOVE(&nbl_adapter_list, adapter, next);
@@ -591,11 +593,11 @@ static int nbl_mdev_unmap_device(struct nbl_adapter 
*adapter)
                if (ret)
                        NBL_LOG(ERR, "unset container, error %i (%s) %d",
                                errno, strerror(errno), ret);
-               nbl_group_count--;
+               last_group = rte_usage_count_release(&nbl_group_count);
                close(vfio_group_fd);
                common->groupfd = -1;
        }
-       if (!nbl_group_count) {
+       if (last_group) {
                rte_mem_event_callback_unregister(NBL_USERDEV_EVENT_CLB_NAME, 
NULL);
                nbl_userdev_dma_free();
        }
-- 
2.52.0