Mastering Linux Kernel Development

Alternate spinlock APIs

Standard spinlock operations that we discussed so far are suitable for the protection of shared resources that are accessed only from the process context kernel path. However, there might be scenarios where a specific shared resource or data might be accessed from both the process and interrupt context code of a kernel service. For instance, think of a device driver service that might contain both process context and interrupt context routines, both programmed to access the shared driver buffer for execution of appropriate I/O operations.

Let's presume that a spinlock was engaged to protect the driver's shared resource from concurrent access, and all routines of the driver service (both process and interrupt context) ...