arm/arm64 pmu: add a PMCDBG to interrupt handler

[mhorne]

Oops, looks like I already handled this a while ago in 13f5a3076. This was from an old branch, and doesn't work anyway because PMCDBG will fail to link when used outside of the hwpmc module.

sys/arm/arm/pmu.c

struct bus_dma_tag_iommu {
         bus_dma_segment_t *segments;
 };
 
 struct bus_dmamap_iommu {
         struct bus_dma_tag_iommu *tag;
         struct memdesc mem;
         bus_dmamap_callback_t *callback;
         void *callback_arg;
+        struct mtx lock;
         struct iommu_map_entries_tailq map_entries;
         TAILQ_ENTRY(bus_dmamap_iommu) delay_link;
         bool locked;
         bool cansleep;
         int flags;
 #ifdef KMSAN
         struct memdesc kmsan_mem;
 #endif
 };
+
+#define IOMMU_DMAMAP_INIT(map)          mtx_init(&(map)->lock, \
+                                            "iommu dmamap", NULL, MTX_DEF)
+#define IOMMU_DMAMAP_DESTROY(map)       mtx_destroy(&(map)->lock)
+#define IOMMU_DMAMAP_LOCK(map)          mtx_lock(&(map)->lock)
+#define IOMMU_DMAMAP_UNLOCK(map)        mtx_unlock(&(map)->lock)
 
 #define BUS_DMAMAP_IOMMU_MALLOC 0x0001
 #define BUS_DMAMAP_IOMMU_KMEM_ALLOC 0x0002
 
 extern struct bus_dma_impl bus_dma_iommu_impl;
 
 #endif