+/* allocates the memory where the IOMMU will log its events to */
+static u8 * __init alloc_event_buffer(struct amd_iommu *iommu)
+{
+ u64 entry;
+ iommu->evt_buf = (u8 *)__get_free_pages(GFP_KERNEL | __GFP_ZERO,
+ get_order(EVT_BUFFER_SIZE));
+
+ if (iommu->evt_buf == NULL)
+ return NULL;
+
+ entry = (u64)virt_to_phys(iommu->evt_buf) | EVT_LEN_MASK;
+ memcpy_toio(iommu->mmio_base + MMIO_EVT_BUF_OFFSET,
+ &entry, sizeof(entry));
+
+ iommu->evt_buf_size = EVT_BUFFER_SIZE;
+
+ return iommu->evt_buf;
+}
+
+static void __init free_event_buffer(struct amd_iommu *iommu)
+{
+ free_pages((unsigned long)iommu->evt_buf, get_order(EVT_BUFFER_SIZE));
+}
+