IOMMU(三)-初始化

enum acpi_dmar_type {
	ACPI_DMAR_TYPE_HARDWARE_UNIT = 0,
	ACPI_DMAR_TYPE_RESERVED_MEMORY = 1,
	ACPI_DMAR_TYPE_ROOT_ATS = 2,
	ACPI_DMAR_TYPE_HARDWARE_AFFINITY = 3,
	ACPI_DMAR_TYPE_NAMESPACE = 4,
	ACPI_DMAR_TYPE_RESERVED = 5	/* 5 and greater are reserved */
};

struct iommu_table_entry {
	initcall_t	detect;
	initcall_t	depend;
	void		(*early_init)(void); /* No memory allocate available. */
	void		(*late_init)(void); /* Yes, can allocate memory. */
#define IOMMU_FINISH_IF_DETECTED (1<<0)
#define IOMMU_DETECTED		 (1<<1)
	int		flags;
};
#define __IOMMU_INIT(_detect, _depend, _early_init, _late_init, _finish)\
	static const struct iommu_table_entry				\
		__iommu_entry_##_detect __used				\
	__attribute__ ((unused, __section__(".iommu_table"),		\
			aligned((sizeof(void *)))))	\
	= {_detect, _depend, _early_init, _late_init,			\
	   _finish ? IOMMU_FINISH_IF_DETECTED : 0}
#define IOMMU_INIT_POST(_detect)					\
	__IOMMU_INIT(_detect, pci_swiotlb_detect_4gb,  NULL, NULL, 0)
IOMMU_INIT_POST(detect_intel_iommu);

struct acpi_table_header * __initdata dmar_tbl;
static acpi_size dmar_tbl_size;
start_kernel
  └─mm_init
      └─mem_init
          └─pci_iommu_alloc
              ├─sort_iommu_table
              ├─check_iommu_entries
              └─detect_intel_iommu
                  ├─dmar_table_detect
                  |   └─acpi_get_table_with_size
                  |       └─dmar_walk_remapping_entries
                  |           └─dmar_validate_one_drhd
                  ├─dmar_walk_dmar_table
                  ├─pci_request_acs
                  └─x86_init.iommu.iommu_init = intel_iommu_init

struct list_head dmar_drhd_units;
static LIST_HEAD(dmar_rmrr_units);
pci_iommu_init
  └─intel_iommu_init
      ├─dmar_table_init
      ├─parse_dmar_table
      |   ├─dmar_table_detect
      |   └─dmar_walk_remapping_entries
      |       ├─dmar_parse_one_drhd
      |       |  ├─dmar_find_dmaru
      |       |  ├─dmar_alloc_dev_scope//分配好多空内存
      |       |  ├─alloc_iommu
      |       |  |   └─map_iommu
      |       |  └─dmar_register_drhd_unit
      |       ├─dmar_parse_one_rmrr
      |       ├─dmar_parse_one_atsr
      |       ├─dmar_parse_one_rhsa
      |       └─dmar_parse_one_andd
      ├─dmar_dev_scope_init
      | ├─dmar_acpi_dev_scope_init
      | |     └─for(dev_scope_num in acpi table)
      | |           ├─acpi_bus_get_device
      | |           └─dmar_acpi_insert_dev_scope//给上面注释中指的内存空间中写dev/bus
      | └─for_each_pci_dev(dev)//把非acpi上报的dev上搞到iommu中来
      |     ├─dmar_alloc_pci_notify_info
      |     ├─dmar_pci_bus_add_dev
      |     |   ├─for_each_drhd_unit//找到dev的hrhd然后加入
      |     |   |    └─dmar_insert_dev_scope
      |     |   ├─dmar_iommu_notify_scope_dev
      |     |   └─intel_irq_remap_add_device
      |     └─dmar_free_pci_notify_info
      ├─init_dmars//后面单独分析
      ├─bus_set_iommu//后面单独分析
      └─for_each_iommu
             └─iommu_enable_translation

init_dmars
  ├─for_each_iommu
  |   ├─intel_iommu_init_qi//软件给硬件通过这块内存提交任务，硬件清自己的iotlb缓存
  |   |   └─dmar_enable_qi
  |   |       └─__dmar_enable_qi//写硬件寄存器
  |   ├─iommu_init_domains//分配了很多struct dmar_domain
  |   └─iommu_alloc_root_entry
  ├─for_each_active_iommu
  |   ├─iommu_flush_write_buffer
  |   └─iommu_set_root_entry//写硬件寄存器
  ├─si_domain_init
  |   ├─alloc_domain(DOMAIN_FLAG_STATIC_IDENTITY)//额外创建一个domain
  |   ├─for_each_online_node//在这个domain中dma地址和物理地址一一对应
  |   |   └─for_each_mem_pfn_range
  |   |       └─iommu_domain_identity_map
  |   |           └─__domain_mapping
  |   └─for_each_rmrr_units//rmrr内存在这个domain中一一对应
  |      └─for_each_active_dev_scope
  |           └─iommu_domain_identity_map
  └─for_each_iommu
      ├─iommu_flush_write_buffer
      └─dmar_set_interrupt//iommu硬件自己的中断
          ├─dmar_alloc_hwirq
          └─request_irq(irq, dmar_fault)

/*
 * This are the possible domain-types
 *
 *	IOMMU_DOMAIN_BLOCKED	- All DMA is blocked, can be used to isolate
 *				  devices
 *	IOMMU_DOMAIN_IDENTITY	- DMA addresses are system physical addresses
 *	IOMMU_DOMAIN_UNMANAGED	- DMA mappings managed by IOMMU-API user, used
 *				  for VMs
 *	IOMMU_DOMAIN_DMA	- Internally used for DMA-API implementations.
 *				  This flag allows IOMMU drivers to implement
 *				  certain optimizations for these domains
 */

bus_set_iommu
  └─iommu_bus_init
      ├─bus_iommu_probe//处理bus上的设备
      |   ├─bus_for_each_dev//给dev分配group，
      |   |   └─probe_iommu_group
      |   |        └─__iommu_probe_device
      |   |             ├─intel_iommu_probe_device
      |   |             └─iommu_group_get_for_dev
      |   |                   └─pci_device_group//真正决定group的函数
      |   └─for_each_group
      |        ├─probe_alloc_default_domain//给内核管理的dev分配default domain
      |        ├─iommu_group_create_direct_mappings//对系统保留区分建立mapping，如dev和ioapic的关系
      |        |   └─iommu_create_device_direct_mappings
      |        |       ├─list_for_each_entry
      |        |       |   ├─iommu_iova_to_phys
      |        |       |   └─iommu_map
      |        |       └─iommu_flush_iotlb_all
      |        ├─__iommu_group_dma_attach
      |        |     └─dmar_insert_one_dev_info//创建这个dev在IOMMU中的转换表
      |        └─__iommu_group_dma_finalize
      |              └─intel_iommu_probe_finalize
      |                  └─iommu_dma_init_domain//给dev分配iova并且flush到硬件上
      └─bus_register_notifier(iommu_bus_notifier)//用于处理hotplug的设备