常州哪家公司做网站,哪个厂家的logo品牌设计,关键词林俊杰百度云,网站seo怎么做知乎1.简介
Linux内核PCIe软件框架如下图所示#xff0c;按照PCIe的模式#xff0c;可分为RC和EP软件框架。RC的软件框架分为五层#xff0c;第一层为RC Controller Driver#xff0c;和RC Controller硬件直接交互#xff0c;不同的RC Controller#xff0c;其驱动实现也不相…1.简介
Linux内核PCIe软件框架如下图所示按照PCIe的模式可分为RC和EP软件框架。RC的软件框架分为五层第一层为RC Controller Driver和RC Controller硬件直接交互不同的RC Controller其驱动实现也不相同第二层为Core层该层将Controller进行了抽象提供了统一的接口和数据结构将所有的Controller管理起来同时提供通用PCIe设备驱动注册和匹配接口完成驱动和设备的绑定管理所有PCIe设备第三层为PCIe设备驱动层包含了Storage、Ethernet、PCI桥等设备驱动第四层为设备驱动层根据设备类型可分为字符设备驱动、网络设备驱动和块设备驱动。第五层为虚拟文件系统层该层会在用户空间创建设备节点提供了应用程序访问PCIe设备的路径。EP的软件框架分为六层第一层为EP Controller Driver和RC Controller Driver的功能相似第二层为EP Controller Core层该层向下将EP Controller进行了抽象提供了统一的接口和数据结构将所有的EP Controller管理起来第三层为EP Function Core该层统一管理EPF驱动和EPF设备并提供两者相互匹配的方法第四层为EP Configfs在用户空间提供了配置和绑定EPF的接口用户可以通过这些接口配置EPF而无需修改驱动第五层为EP Function Driver和PCIe设备的具体功能相关第六层为虚拟文件系统层和RC的功能相同EP也有设备驱动层篇幅所限图中未画出。 2.RC软件框架
2.1.RC Controller Driver
RK3588 PCIe RC Controller Driver驱动定义如下所示。
MODULE_DEVICE_TABLE(of, rk_pcie_of_match);
static struct platform_driver rk_plat_pcie_driver {.driver {.name rk-pcie,.of_match_table rk_pcie_of_match,.suppress_bind_attrs true,.pm rockchip_dw_pcie_pm_ops,},.probe rk_pcie_probe,
};module_platform_driver(rk_plat_pcie_driver);2.2.Core
2.2.1.Host Bridge
RC Core层使用struct pci_host_bridge数据结构描述Host Bridge。bus描述Root bus其他bus都在该数据结构的链表中。ops和child_ops描述Root bus和其他bus上的设备的配置空间访问方法。windows链表保存bus-range和ranges的资源。dma_ranges链表保存dma-ranges的资源。使用pci_alloc_host_bridge和devm_pci_alloc_host_bridge函数分配struct pci_host_bridge数据结构使用pci_free_host_bridge释放struct pci_host_bridge数据结构。pci_host_probe枚举Host Bridge下面所有PCIe设备。
[include/linux/pci.h]
struct pci_host_bridge {struct device dev;struct pci_bus *bus; /* Root bus */struct pci_ops *ops; /* Low-level architecture-dependent routines */struct pci_ops *child_ops;void *sysdata;int busnr;struct list_head windows; /* resource_entry */struct list_head dma_ranges; /* dma ranges resource list */......
};
struct pci_host_bridge *pci_alloc_host_bridge(size_t priv);
struct pci_host_bridge *devm_pci_alloc_host_bridge(struct device *dev,size_t priv);
void pci_free_host_bridge(struct pci_host_bridge *bridge);
int pci_host_probe(struct pci_host_bridge *bridge);struct pci_ops描述访问PCIe设备配置空间的方法需要RC Controller Driver实现。常用的是map_bus、read和writemap_bus用于映射访问配置空间的regionread和write用于读写配置空间。
[include/linux/pci.h]
struct pci_ops {int (*add_bus)(struct pci_bus *bus);void (*remove_bus)(struct pci_bus *bus);void __iomem *(*map_bus)(struct pci_bus *bus, unsigned int devfn, int where);int (*read)(struct pci_bus *bus, unsigned int devfn, int where, int size, u32 *val);int (*write)(struct pci_bus *bus, unsigned int devfn, int where, int size, u32 val);
};2.2.2.Bus
RC Core层使用struct pci_bus数据结构描述PCIe bus。所有PCIe bus组成一个PCIe树型结构。parent指向Parent buseschildren指向Child buses。devices链表保存该bus上的所有设备。number为该bus的总线编号primary表示上游总线编号busn_res保存桥下游总线编号范围max_bus_speed表示该bus支持的最大速度cur_bus_speed表示该bus当前的速度。pci_find_bus根据PCIe域和总线编号查找struct pci_buspci_add_new_bus创建一个struct pci_bus并添加到父总线上注册Host Bridge时会自动创建bus0的数据结构pci_bus_insert_busn_res和pci_bus_update_busn_res_end更新PCIe bus编号资源。
[include/linux/pci.h]
struct pci_bus {struct list_head node; /* Node in list of buses */struct pci_bus *parent; /* Parent bus this bridge is on */struct list_head children; /* List of child buses */struct list_head devices; /* List of devices on this bus */struct pci_dev *self; /* Bridge device as seen by parent */struct list_head slots; /* List of slots on this bus;protected by pci_slot_mutex */struct resource *resource[PCI_BRIDGE_RESOURCE_NUM];struct list_head resources; /* Address space routed to this bus */struct resource busn_res; /* Bus numbers routed to this bus */struct pci_ops *ops; /* Configuration access functions */struct msi_controller *msi; /* MSI controller */void *sysdata; /* Hook for sys-specific extension */struct proc_dir_entry *procdir; /* Directory entry in /proc/bus/pci */unsigned char number; /* Bus number */unsigned char primary; /* Number of primary bridge */unsigned char max_bus_speed; /* enum pci_bus_speed */unsigned char cur_bus_speed; /* enum pci_bus_speed */......
};struct pci_bus *pci_find_bus(int domain, int busnr);
struct pci_bus *pci_add_new_bus(struct pci_bus *parent,struct pci_dev *dev, int busnr);
void pci_remove_bus(struct pci_bus *bus);int pci_bus_insert_busn_res(struct pci_bus *b, int bus, int busmax);
int pci_bus_update_busn_res_end(struct pci_bus *b, int busmax);2.2.3.Device
RC Core层使用struct pci_dev数据结构描述PCIe Devices。devfn表述device和function编号vendor、device等保存PCIe设备配置空间头信息driver指向该设备使用的驱动。resource保存设备的资源如BAR、ROMs等。PCIe bus也是一个PCIe设备。pci_alloc_dev分配struct pci_dev数据结构pci_dev_put释放struct pci_dev数据结构pci_device_add向总线上添加PCIe设备。pci_bus_add_devices和pci_bus_add_device匹配PCIe设备和PCIe驱动。
[include/linux/pci.h]
/* The pci_dev structure describes PCI devices */
struct pci_dev {struct list_head bus_list; /* Node in per-bus list */struct pci_bus *bus; /* Bus this device is on */struct pci_bus *subordinate; /* Bus this device bridges to */void *sysdata; /* Hook for sys-specific extension */struct proc_dir_entry *procent; /* Device entry in /proc/bus/pci */struct pci_slot *slot; /* Physical slot this device is in */unsigned int devfn; /* Encoded device function index */unsigned short vendor;unsigned short device;unsigned short subsystem_vendor;unsigned short subsystem_device;unsigned int class; /* 3 bytes: (base,sub,prog-if) */......struct pci_driver *driver; /* Driver bound to this device */......int cfg_size; /* Size of config space *//** Instead of touching interrupt line and base address registers* directly, use the values stored here. They might be different!*/unsigned int irq;struct resource resource[DEVICE_COUNT_RESOURCE]; /* I/O and memory regions expansion ROMs */bool match_driver; /* Skip attaching driver */......
};struct pci_dev *pci_alloc_dev(struct pci_bus *bus);
void pci_dev_put(struct pci_dev *dev);
void pci_device_add(struct pci_dev *dev, struct pci_bus *bus);
void pci_bus_add_device(struct pci_dev *dev);
void pci_bus_add_devices(const struct pci_bus *bus);2.2.4.Driver
RC Core层使用struct pci_driver数据结构描述PCIe设备驱动。PCIe设备和驱动匹配的信息保存到id_table中。pci_register_driver注册PCIe设备驱动pci_unregister_driver注销PCIe设备驱动。
[include/linux/pci.h]
struct pci_driver {struct list_head node;const char *name;/* Must be non-NULL for probe to be called */const struct pci_device_id *id_table;/* New device inserted */int (*probe)(struct pci_dev *dev, const struct pci_device_id *id);/* Device removed (NULL if not a hot-plug capable driver) */void (*remove)(struct pci_dev *dev);/* Device suspended */int (*suspend)(struct pci_dev *dev, pm_message_t state);/* Device woken up */int (*resume)(struct pci_dev *dev);void (*shutdown)(struct pci_dev *dev);/* On PF */int (*sriov_configure)(struct pci_dev *dev, int num_vfs);/* */const struct pci_error_handlers *err_handler;......
};
/* pci_register_driver() must be a macro so KBUILD_MODNAME can be expanded */
#define pci_register_driver(driver) \__pci_register_driver(driver, THIS_MODULE, KBUILD_MODNAME)void pci_unregister_driver(struct pci_driver *dev);pci_bus_type用于匹配PCIe设备和驱动。
struct bus_type pci_bus_type {.name pci,.match pci_bus_match,.uevent pci_uevent,.probe pci_device_probe,.remove pci_device_remove,.shutdown pci_device_shutdown,.dev_groups pci_dev_groups,.bus_groups pci_bus_groups,.drv_groups pci_drv_groups,.pm PCI_PM_OPS_PTR,.num_vf pci_bus_num_vf,.dma_configure pci_dma_configure,
};2.2.5.设备驱动
不同的PCIe设备需要不同的PCIe设备驱动。下面列出PCIe桥和NVMe硬盘驱动。
2.2.5.1.桥驱动
如下所示PCIe桥使用pcieport驱动。
[drivers/pci/pcie/portdrv_pci.c]
static const struct pci_device_id port_pci_ids[] {/* handle any PCI-Express port */{ PCI_DEVICE_CLASS(((PCI_CLASS_BRIDGE_PCI 8) | 0x00), ~0) },/* subtractive decode PCI-to-PCI bridge, class type is 060401h */{ PCI_DEVICE_CLASS(((PCI_CLASS_BRIDGE_PCI 8) | 0x01), ~0) },/* handle any Root Complex Event Collector */{ PCI_DEVICE_CLASS(((PCI_CLASS_SYSTEM_RCEC 8) | 0x00), ~0) },{ },
};
static struct pci_driver pcie_portdriver {.name pcieport,.id_table port_pci_ids[0],.probe pcie_portdrv_probe,.remove pcie_portdrv_remove,.shutdown pcie_portdrv_remove,.err_handler pcie_portdrv_err_handler,.driver.pm PCIE_PORTDRV_PM_OPS,
};
static int __init pcie_portdrv_init(void)
{if (pcie_ports_disabled)return -EACCES;pcie_init_services();dmi_check_system(pcie_portdrv_dmi_table);return pci_register_driver(pcie_portdriver);
}
device_initcall(pcie_portdrv_init);2.2.5.2.NVMe驱动
M.2 NVMe硬盘使用下面的驱动。
[drivers/nvme/host/pci.c]
static struct pci_driver nvme_driver {.name nvme,.id_table nvme_id_table,.probe nvme_probe,.remove nvme_remove,.shutdown nvme_shutdown,
#ifdef CONFIG_PM_SLEEP.driver {.pm nvme_dev_pm_ops,},
#endif.sriov_configure pci_sriov_configure_simple,.err_handler nvme_err_handler,
};static int __init nvme_init(void)
{BUILD_BUG_ON(sizeof(struct nvme_create_cq) ! 64);BUILD_BUG_ON(sizeof(struct nvme_create_sq) ! 64);BUILD_BUG_ON(sizeof(struct nvme_delete_queue) ! 64);BUILD_BUG_ON(IRQ_AFFINITY_MAX_SETS 2);return pci_register_driver(nvme_driver);
}
module_init(nvme_init);
module_exit(nvme_exit);3.EP软件框架
3.1.EP Controller Driver
RK3399 PCIe EP Controller Driverr驱动定义如下所示。
[drivers/pci/controller/pcie-rockchip-ep.c]
static const struct of_device_id rockchip_pcie_ep_of_match[] {{ .compatible rockchip,rk3399-pcie-ep},{},
};static struct platform_driver rockchip_pcie_ep_driver {.driver {.name rockchip-pcie-ep,.of_match_table rockchip_pcie_ep_of_match,},.probe rockchip_pcie_ep_probe,
};builtin_platform_driver(rockchip_pcie_ep_driver);3.2.EP Controller Core
3.2.1.EPC Device
EP Controller Core层使用struct pci_epc描述PCIe Endpoint Controller Device。EPC的所有的functions都挂到pci_epf链表上ops指向了EPC提供的回调函数集合用于设置EPC的配置空间、设置region、设置和发送中断等windows保存了EPC的Outbound的地址段num_windows表示Outbound的地址段的数量max_functions保存了functions的最大数量。使用pci_epc_create和devm_pci_epc_create函数创建struct pci_epcdevm_pci_epc_destroy和pci_epc_destroy销毁struct pci_epc。
[include/linux/pci-epc.h]
/* struct pci_epc - represents the PCI EPC device */
struct pci_epc {struct device dev;struct list_head pci_epf;const struct pci_epc_ops *ops;struct pci_epc_mem **windows;struct pci_epc_mem *mem;unsigned int num_windows;u8 max_functions;struct config_group *group;/* mutex to protect against concurrent access of EP controller */struct mutex lock;unsigned long function_num_map;struct atomic_notifier_head notifier;
};#define pci_epc_create(dev, ops) \__pci_epc_create((dev), (ops), THIS_MODULE)
#define devm_pci_epc_create(dev, ops) \__devm_pci_epc_create((dev), (ops), THIS_MODULE)
void devm_pci_epc_destroy(struct device *dev, struct pci_epc *epc);
void pci_epc_destroy(struct pci_epc *epc);struct pci_epc_ops如下图所示这些回调函数很重要EP Controller Driver必须实现。EPF驱动会调用这些函数配置EPC。
[include/linux/pci-epc.h]
struct pci_epc_ops {int (*write_header)(struct pci_epc *epc, u8 func_no,struct pci_epf_header *hdr);int (*set_bar)(struct pci_epc *epc, u8 func_no,struct pci_epf_bar *epf_bar);void (*clear_bar)(struct pci_epc *epc, u8 func_no,struct pci_epf_bar *epf_bar);int (*map_addr)(struct pci_epc *epc, u8 func_no,phys_addr_t addr, u64 pci_addr, size_t size);void (*unmap_addr)(struct pci_epc *epc, u8 func_no,phys_addr_t addr);int (*set_msi)(struct pci_epc *epc, u8 func_no, u8 interrupts);int (*get_msi)(struct pci_epc *epc, u8 func_no);int (*set_msix)(struct pci_epc *epc, u8 func_no, u16 interrupts,enum pci_barno, u32 offset);int (*get_msix)(struct pci_epc *epc, u8 func_no);int (*raise_irq)(struct pci_epc *epc, u8 func_no,enum pci_epc_irq_type type, u16 interrupt_num);int (*start)(struct pci_epc *epc);void (*stop)(struct pci_epc *epc);const struct pci_epc_features* (*get_features)(struct pci_epc *epc,u8 func_no);struct module *owner;
};3.2.2.EPF绑定EPC
每个EP的Function都对应一个struct pci_epf设备即EPF设备EPF设备和EPC通过pci_epc_add_epf绑定通过pci_epc_remove_epf解除绑定。
[include/linux/pci-epc.h]
int pci_epc_add_epf(struct pci_epc *epc, struct pci_epf *epf);
void pci_epc_remove_epf(struct pci_epc *epc, struct pci_epf *epf);3.2.3.EPC API
下面的接口是对struct pci_epc_ops封装供EPF驱动调用。
[include/linux/pci-epc.h]
int pci_epc_write_header(struct pci_epc *epc, u8 func_no,struct pci_epf_header *hdr);
int pci_epc_set_bar(struct pci_epc *epc, u8 func_no,struct pci_epf_bar *epf_bar);
void pci_epc_clear_bar(struct pci_epc *epc, u8 func_no,struct pci_epf_bar *epf_bar);
int pci_epc_map_addr(struct pci_epc *epc, u8 func_no,phys_addr_t phys_addr,u64 pci_addr, size_t size);
void pci_epc_unmap_addr(struct pci_epc *epc, u8 func_no,phys_addr_t phys_addr);
int pci_epc_set_msi(struct pci_epc *epc, u8 func_no, u8 interrupts);
int pci_epc_get_msi(struct pci_epc *epc, u8 func_no);
int pci_epc_set_msix(struct pci_epc *epc, u8 func_no, u16 interrupts,enum pci_barno, u32 offset);
int pci_epc_get_msix(struct pci_epc *epc, u8 func_no);
int pci_epc_raise_irq(struct pci_epc *epc, u8 func_no,enum pci_epc_irq_type type, u16 interrupt_num);
int pci_epc_start(struct pci_epc *epc);
void pci_epc_stop(struct pci_epc *epc);
const struct pci_epc_features *pci_epc_get_features(struct pci_epc *epc,u8 func_no);3.3.EP Function Core
EP Function Core层定义了EPF Driver和EPF Device的数据结构并提供注册、创建及绑定接口。
3.3.1.EPF Driver
EPF Driver的数据结构为struct pci_epf_driver。当EPF Device和EPC Device绑定后会回调ops函数以通知EPF Driverid_table定义EPF Driver和EPF Device匹配的信息。pci_epf_register_driver注册EPF Driverpci_epf_unregister_driver注销EPF Driver。
[include/linux/pci-epf.h]
struct pci_epf_driver {int (*probe)(struct pci_epf *epf);int (*remove)(struct pci_epf *epf);struct device_driver driver;struct pci_epf_ops *ops;struct module *owner;struct list_head epf_group;const struct pci_epf_device_id *id_table;
};
struct pci_epf_ops {int (*bind)(struct pci_epf *epf);void (*unbind)(struct pci_epf *epf);
};#define pci_epf_register_driver(driver) \__pci_epf_register_driver((driver), THIS_MODULE)
void pci_epf_unregister_driver(struct pci_epf_driver *driver);3.3.2.EPF Device
每个EP Function都对应一个EPF Device。EPF Device的数据结构为struct pci_epf_driver。header保存了该EP Function配置空间头信息bar[6]保存了6个BAR映射的物理地址msi_interrupts和msix_interrupts分别表示EP Function需要的中断数量func_no表述EP Function的编号。pci_epf_create和pci_epf_destroy创建和销毁EPF Device。
[include/linux/pci-epf.h]
struct pci_epf {struct device dev;const char *name;struct pci_epf_header *header;struct pci_epf_bar bar[6];u8 msi_interrupts;u16 msix_interrupts;u8 func_no;struct pci_epc *epc;struct pci_epf_driver *driver;struct list_head list;struct notifier_block nb;/* mutex to protect against concurrent access of pci_epf_ops */struct mutex lock;
};
struct pci_epf *pci_epf_create(const char *name);
void pci_epf_destroy(struct pci_epf *epf);3.3.3.EPF Device匹配EPF Driver
pci_epf_bus_type用于匹配EPF Device和EPF Driver。
[drivers/pci/endpoint/pci-epf-core.c]
static struct bus_type pci_epf_bus_type {.name pci-epf,.match pci_epf_device_match,.probe pci_epf_device_probe,.remove pci_epf_device_remove,
};3.4.EP Configfs
EP Configfs会在/sys目录下创建文件节点使用者可以在用户空间通过这些文件节点配置和创建EPP Device绑定EPP Device、EPP Driver及EPC Device。
3.5.EP Function Driver。
下面是pci_epf_test的EP Function Driver。
[drivers/pci/endpoint/functions/pci-epf-test.c]
static struct pci_epf_ops ops {.unbind pci_epf_test_unbind,.bind pci_epf_test_bind,
};static struct pci_epf_driver test_driver {.driver.name pci_epf_test,.probe pci_epf_test_probe,.id_table pci_epf_test_ids,.ops ops,.owner THIS_MODULE,
};参考资料
PCIEXPRESS体系结构导读PCI Express technology 3.0PCI Express® Base Specification Revision 5.0 Version 1.0Rockchip RK3588 TRMLinux kernel 5.10
