• Preface
  • Jon's Introduction
  • Alessandro's Introduction
  • Greg's Introduction
  • Audience for This Book
  • Organization of the Material
  • Background Information
  • Online Version and License
  • Conventions Used in This Book
  • Using Code Examples
  • We'd Like to Hear from You
  • Safari Enabled
  • Acknowledgments
  • Jon
  • Alessandro
  • Greg
• An Introduction to Device Drivers
  • The Role of the Device Driver
  • Splitting the Kernel
  • Loadable Modules
  • Classes of Devices and Modules
  • Security Issues
  • Version Numbering
  • License Terms
  • Joining the Kernel Development Community
  • Overview of the Book
• Building and Running Modules
  • Setting Up Your Test System
  • The Hello World Module
  • Kernel Modules Versus Applications
  • User Space and Kernel Space
  • Concurrency in the Kernel
  • The Current Process
  • A Few Other Details
  • Compiling and Loading
  • Compiling Modules
  • Loading and Unloading Modules
  • Version Dependency
  • Platform Dependency
  • The Kernel Symbol Table
  • Preliminaries
  • Initialization and Shutdown
  • The Cleanup Function
  • Error Handling During Initialization
  • Module-Loading Races
  • Module Parameters
  • Doing It in User Space
  • Quick Reference
• Char Drivers
  • The Design of scull
  • Major and Minor Numbers
  • The Internal Representation of Device Numbers
  • Allocating and Freeing Device Numbers
  • Dynamic Allocation of Major Numbers
  • Some Important Data Structures
  • File Operations
  • The file Structure
  • The inode Structure
  • Char Device Registration
  • Device Registration in scull
  • The Older Way
  • open and release
  • The open Method
  • The release Method
  • scull's Memory Usage
  • read and write
  • The read Method
  • The write Method
  • readv and writev
  • Playing with the New Devices
  • Quick Reference
• Debugging Techniques
  • Debugging Support in the Kernel
  • Debugging by Printing
  • printk
  • Redirecting Console Messages
  • How Messages Get Logged
  • Turning the Messages On and Off
  • Rate Limiting
  • Printing Device Numbers
  • Debugging by Querying
  • Using the /proc Filesystem
  • Implementing files in /proc
  • An older interface
  • Creating your /proc file
  • The seq_file interface
  • The ioctl Method
  • Debugging by Watching
  • Debugging System Faults
  • Oops Messages
  • System Hangs
  • Debuggers and Related Tools
  • Using gdb
  • The kdb Kernel Debugger
  • The kgdb Patches
  • The User-Mode Linux Port
  • The Linux Trace Toolkit
  • Dynamic Probes
• Concurrency and Race Conditions
  • Pitfalls in scull
  • Concurrency and Its Management
  • Semaphores and Mutexes
  • The Linux Semaphore Implementation
  • Using Semaphores in scull
  • Reader/Writer Semaphores
  • Completions
  • Spinlocks
  • Introduction to the Spinlock API
  • Spinlocks and Atomic Context
  • The Spinlock Functions
  • Reader/Writer Spinlocks
  • Locking Traps
  • Ambiguous Rules
  • Lock Ordering Rules
  • Fine- Versus Coarse-Grained Locking
  • Alternatives to Locking
  • Lock-Free Algorithms
  • Atomic Variables
  • Bit Operations
  • seqlocks
  • Read-Copy-Update
  • Quick Reference
• Advanced Char Driver Operations
  • ioctl
  • Choosing the ioctl Commands
  • The Return Value
  • The Predefined Commands
  • Using the ioctl Argument
  • Capabilities and Restricted Operations
  • The Implementation of the ioctl Commands
  • Device Control Without ioctl
  • Blocking I/O
  • Introduction to Sleeping
  • Simple Sleeping
  • Blocking and Nonblocking Operations
  • A Blocking I/O Example
  • Advanced Sleeping
  • How a process sleeps
  • Manual sleeps
  • Exclusive waits
  • The details of waking up
  • Ancient history: sleep_on
  • Testing the Scullpipe Driver
  • poll and select
  • Interaction with read and write
  • Reading data from the device
  • Writing to the device
  • Flushing pending output
  • The Underlying Data Structure
  • Asynchronous Notification
  • The Driver's Point of View
  • Seeking a Device
  • The llseek Implementation
  • Access Control on a Device File
  • Single-Open Devices
  • Restricting Access to a Single User at a Time
  • Blocking open as an Alternative to EBUSY
  • Cloning the Device on open
  • Quick Reference
• Time, Delays, and Deferred Work
  • Measuring Time Lapses
  • Using the jiffies Counter
  • Processor-Specific Registers
  • Knowing the Current Time
  • Delaying Execution
  • Long Delays
  • Busy waiting
  • Yielding the processor
  • Timeouts
  • Short Delays
  • Kernel Timers
  • The Timer API
  • The Implementation of Kernel Timers
  • Tasklets
  • Workqueues
  • The Shared Queue
  • Quick Reference
  • Timekeeping
  • Delays
  • Kernel Timers
  • Tasklets
  • Workqueues
• Allocating Memory
  • The Real Story of kmalloc
  • The Flags Argument
  • Memory zones
  • The Size Argument
  • Lookaside Caches
  • A scull Based on the Slab Caches: scullc
  • Memory Pools
  • get_free_page and Friends
  • A scull Using Whole Pages: scullp
  • The alloc_pages Interface
  • vmalloc and Friends
  • A scull Using Virtual Addresses: scullv
  • Per-CPU Variables
  • Obtaining Large Buffers
  • Acquiring a Dedicated Buffer at Boot Time
  • Quick Reference
• Communicating with Hardware
  • I/O Ports and I/O Memory
  • I/O Registers and Conventional Memory
  • Using I/O Ports
  • I/O Port Allocation
  • Manipulating I/O ports
  • I/O Port Access from User Space
  • String Operations
  • Pausing I/O
  • Platform Dependencies
  • An I/O Port Example
  • An Overview of the Parallel Port
  • A Sample Driver
  • Using I/O Memory
  • I/O Memory Allocation and Mapping
  • Accessing I/O Memory
  • Ports as I/O Memory
  • Reusing short for I/O Memory
  • ISA Memory Below 1 MB
  • isa_readb and Friends
  • Quick Reference
• Interrupt Handling
  • Preparing the Parallel Port
  • Installing an Interrupt Handler
  • The /proc Interface
  • Auto-Detecting the IRQ Number
  • Kernel-assisted probing
  • Do-it-yourself probing
  • Fast and Slow Handlers
  • The internals of interrupt handling on the x86
  • Implementing a Handler
  • Handler Arguments and Return Value
  • Enabling and Disabling Interrupts
  • Disabling a single interrupt
  • Disabling all interrupts
  • Top and Bottom Halves
  • Tasklets
  • Workqueues
  • Interrupt Sharing
  • Installing a Shared Handler
  • Running the Handler
  • The /proc Interface and Shared Interrupts
  • Interrupt-Driven I/O
  • A Write-Buffering Example
  • Quick Reference
• Data Types in the Kernel
  • Use of Standard C Types
  • Assigning an Explicit Size to Data Items
  • Interface-Specific Types
  • Other Portability Issues
  • Time Intervals
  • Page Size
  • Byte Order
  • Data Alignment
  • Pointers and Error Values
  • Linked Lists
  • Quick Reference
• PCI Drivers
  • The PCI Interface
  • PCI Addressing
  • Boot Time
  • Configuration Registers and Initialization
  • MODULE_DEVICE_TABLE
  • Registering a PCI Driver
  • Old-Style PCI Probing
  • Enabling the PCI Device
  • Accessing the Configuration Space
  • Accessing the I/O and Memory Spaces
  • PCI Interrupts
  • Hardware Abstractions
  • A Look Back: ISA
  • Hardware Resources
  • ISA Programming
  • The Plug-and-Play Specification
  • PC/104 and PC/104+
  • Other PC Buses
  • MCA
  • EISA
  • VLB
  • SBus
  • NuBus
  • External Buses
  • Quick Reference
• USB Drivers
  • USB Device Basics
  • Endpoints
  • Interfaces
  • Configurations
  • USB and Sysfs
  • USB Urbs
  • struct urb
  • Creating and Destroying Urbs
  • Interrupt urbs
  • Bulk urbs
  • Control urbs
  • Isochronous urbs
  • Submitting Urbs
  • Completing Urbs: The Completion Callback Handler
  • Canceling Urbs
  • Writing a USB Driver
  • What Devices Does the Driver Support?
  • Registering a USB Driver
  • probe and disconnect in Detail
  • Submitting and Controlling a Urb
  • USB Transfers Without Urbs
  • usb_bulk_msg
  • usb_control_msg
  • Other USB Data Functions
  • Quick Reference
• The Linux Device Model
  • Kobjects, Ksets, and Subsystems
  • Kobject Basics
  • Embedding kobjects
  • Kobject initialization
  • Reference count manipulation
  • Release functions and kobject types
  • Kobject Hierarchies, Ksets, and Subsystems
  • Ksets
  • Operations on ksets
  • Subsystems
  • Low-Level Sysfs Operations
  • Default Attributes
  • Nondefault Attributes
  • Binary Attributes
  • Symbolic Links
  • Hotplug Event Generation
  • Hotplug Operations
  • Buses, Devices, and Drivers
  • Buses
  • Bus registration
  • Bus methods
  • Iterating over devices and drivers
  • Bus attributes
  • Devices
  • Device registration
  • Device attributes
  • Device structure embedding
  • Device Drivers
  • Driver structure embedding
  • Classes
  • The class_simple Interface
  • The Full Class Interface
  • Managing classes
  • Class devices
  • Class interfaces
  • Putting It All Together
  • Add a Device
  • Remove a Device
  • Add a Driver
  • Remove a Driver
  • Hotplug
  • Dynamic Devices
  • The /sbin/hotplug Utility
  • IEEE1394 (FireWire)
  • Networking
  • PCI
  • Input
  • USB
  • SCSI
  • Laptop docking stations
  • S/390 and zSeries
  • Using /sbin/hotplug
  • Linux hotplug scripts
  • udev
  • Dealing with Firmware
  • The Kernel Firmware Interface
  • How It Works
  • Quick Reference
  • Kobjects
  • Sysfs Operations
  • Buses, Devices, and Drivers
  • Classes
  • Firmware
• Memory Mapping and DMA
  • Memory Management in Linux
  • Address Types
  • Physical Addresses and Pages
  • High and Low Memory
  • The Memory Map and Struct Page
  • Page Tables
  • Virtual Memory Areas
  • The vm_area_struct structure
  • The Process Memory Map
  • The mmap Device Operation
  • Using remap_pfn_range
  • A Simple Implementation
  • Adding VMA Operations
  • Mapping Memory with nopage
  • Remapping Specific I/O Regions
  • Remapping RAM
  • Remapping RAM with the nopage method
  • Remapping Kernel Virtual Addresses
  • Performing Direct I/O
  • Asynchronous I/O
  • An asynchronous I/O example
  • Direct Memory Access
  • Overview of a DMA Data Transfer
  • Allocating the DMA Buffer
  • Do-it-yourself allocation
  • Bus Addresses
  • The Generic DMA Layer
  • Dealing with difficult hardware
  • DMA mappings
  • Setting up coherent DMA mappings
  • DMA pools
  • Setting up streaming DMA mappings
  • Single-page streaming mappings
  • Scatter/gather mappings
  • PCI double-address cycle mappings
  • A simple PCI DMA example
  • DMA for ISA Devices
  • Registering DMA usage
  • Talking to the DMA controller
  • Quick Reference
  • Introductory Material
  • Implementing mmap
  • Implementing Direct I/O
  • Direct Memory Access
• Block Drivers
  • Registration
  • Block Driver Registration
  • Disk Registration
  • Block device operations
  • The gendisk structure
  • Initialization in sbull
  • A Note on Sector Sizes
  • The Block Device Operations
  • The open and release Methods
  • Supporting Removable Media
  • The ioctl Method
  • Request Processing
  • Introduction to the request Method
  • A Simple request Method
  • Request Queues
  • Queue creation and deletion
  • Queueing functions
  • Queue control functions
  • The Anatomy of a Request
  • The bio structure
  • request structure fields
  • Barrier requests
  • Nonretryable requests
  • Request Completion Functions
  • Working with bios
  • Block requests and DMA
  • Doing without a request queue
  • Some Other Details
  • Command Pre-Preparation
  • Tagged Command Queueing
  • Quick Reference
• Network Drivers
  • How snull Is Designed
  • Assigning IP Numbers
  • The Physical Transport of Packets
  • Connecting to the Kernel
  • Device Registration
  • Initializing Each Device
  • Module Unloading
  • The net_device Structure in Detail
  • Global Information
  • Hardware Information
  • Interface Information
  • The Device Methods
  • Utility Fields
  • Opening and Closing
  • Packet Transmission
  • Controlling Transmission Concurrency
  • Transmission Timeouts
  • Scatter/Gather I/O
  • Packet Reception
  • The Interrupt Handler
  • Receive Interrupt Mitigation
  • Changes in Link State
  • The Socket Buffers
  • The Important Fields
  • Functions Acting on Socket Buffers
  • MAC Address Resolution
  • Using ARP with Ethernet
  • Overriding ARP
  • Non-Ethernet Headers
  • Custom ioctl Commands
  • Statistical Information
  • Multicast
  • Kernel Support for Multicasting
  • A Typical Implementation
  • A Few Other Details
  • Media Independent Interface Support
  • Ethtool Support
  • Netpoll
  • Quick Reference
• TTY Drivers
  • A Small TTY Driver
  • struct termios
  • tty_driver Function Pointers
  • open and close
  • Flow of Data
  • Other Buffering Functions
  • No read Function?
  • TTY Line Settings
  • set_termios
  • tiocmget and tiocmset
  • ioctls
  • proc and sysfs Handling of TTY Devices
  • The tty_driver Structure in Detail
  • The tty_operations Structure in Detail
  • The tty_struct Structure in Detail
  • Quick Reference