zx_cache_flush

Summary

Flush CPU data and/or instruction caches.

Declaration

#include <zircon/syscalls.h>

zx_status_t zx_cache_flush(const void* addr, size_t size, uint32_t options);

Description

zx_cache_flush() flushes CPU caches covering memory in the given virtual address range. If that range of memory is not readable, then the thread may fault as it would for a data read.

options is a bitwise OR of:

• ZX_CACHE_FLUSH_DATA

  Clean (write back) data caches, so previous writes on this CPU are visible in main memory.

• ZX_CACHE_FLUSH_INVALIDATE (valid only when combined with ZX_CACHE_FLUSH_DATA)

  Clean (write back) data caches and then invalidate data caches, so previous writes on this CPU are visible in main memory and future reads on this CPU see external changes to main memory.

• ZX_CACHE_FLUSH_INSN

  Synchronize instruction caches with data caches, so previous writes on this CPU are visible to instruction fetches. If this is combined with ZX_CACHE_FLUSH_DATA, then previous writes will be visible to main memory as well as to instruction fetches.

At least one of ZX_CACHE_FLUSH_DATA and ZX_CACHE_FLUSH_INSN must be included in options.

Rights

TODO(https://fxbug.dev/42107318)

Return value

zx_cache_flush() returns ZX_OK on success, or an error code on failure.

Errors

ZX_ERR_INVALID_ARGS options is invalid.