Here are five possible code completions for the given function:

### Completion 1: Free Memory for NPC PKIND and MCAM

```c
void rvu_npc_freemem(struct rvu *rvu)
{
    struct npc_pkind *pkind = &rvu->hw->pkind;
    struct npc_mcam *mcam = &rvu->hw->mcam;

    if (pkind->mem) {
        free(pkind->mem);
        pkind->mem = NULL;
    }

    if (mcam->mem) {
        free(mcam->mem);
        mcam->mem = NULL;
    }
}
```

### Completion 2: Free Memory for NPC PKIND and MCAM with Error Handling

```c
void rvu_npc_freemem(struct rvu *rvu)
{
    struct npc_pkind *pkind = &rvu->hw->pkind;
    struct npc_mcam *mcam = &rvu->hw->mcam;

    if (pkind->mem) {
        if (free(pkind->mem) != NULL) {
            // Handle free memory error
            printf("Error freeing NPC PKIND memory\n");
        }
        pkind->mem = NULL;
    }

    if (mcam->mem) {
        if (free(mcam->mem) != NULL) {
            // Handle free memory error
            printf("Error freeing NPC MCAM memory\n");
        }
        mcam->mem = NULL;
    }
}
```

### Completion 3: Free Memory for NPC PKIND and MCAM with Memory Leak Detection

```c
void rvu_npc_freemem(struct rvu *rvu)
{
    struct npc_pkind *pkind = &rvu->hw->pkind;
    struct npc_mcam *mcam = &rvu->hw->mcam;

    if (pkind->mem) {
        free(pkind->mem);
        pkind->mem = NULL;
        // Memory leak detection
        if (pkind->mem != NULL) {
            printf("Memory leak detected in NPC PKIND\n");
        }
    }

    if (mcam->mem) {
        free(mcam->mem);
        mcam->mem = NULL;
        // Memory leak detection
        if (mcam->mem != NULL) {
            printf("Memory leak detected in NPC MCAM\n");
        }
    }
}
```

### Completion 4: Free Memory for NPC PKIND and MCAM with Custom Memory Management

```c
void rvu_npc_freemem(struct rvu *rvu)
{
    struct npc_pkind *pkind = &rvu->hw->pkind;
    struct npc_mcam *mcam = &rvu->hw->mcam;

    if (pkind->mem) {
        rvu_custom_free(pkind->mem);
        pkind->mem = NULL;
    }

    if (mcam->mem) {
        rvu_custom_free(mcam->mem);
        mcam->mem = NULL;
    }
}

// Custom memory management function
void rvu_custom_free(void *mem)
{
    // Custom memory deallocation logic
    // ...
}
```

### Completion 5: Free Memory for NPC PKIND and MCAM with Lock Protection

```c
void rvu_npc_freemem(struct rvu *rvu)
{
    struct npc_pkind *pkind = &rvu->hw->pkind;
    struct npc_mcam *mcam = &rvu->hw->mcam;

    // Acquire lock to prevent concurrent access
    pthread_mutex_lock(&rvu->lock);

    if (pkind->mem) {
        free(pkind->mem);
        pkind->mem = NULL;
    }

    if (mcam->mem) {
        free(mcam->mem);
        mcam->mem = NULL;
    }

    // Release lock
    pthread_mutex_unlock(&rvu->lock);
}
```