include/linux/memregion.h

Source file repositories/reference/linux-study-clean/include/linux/memregion.h

File Facts

System
Linux kernel
Corpus path
include/linux/memregion.h
Extension
.h
Size
2075 bytes
Lines
72
Domain
Core OS
Bucket
Core Kernel Interface
Inferred role
Core OS: implementation source
Status
source implementation candidate

Why This File Exists

Core operating-system implementation surface: boot, tasks, memory, VFS, syscall-facing interfaces, synchronization, credentials, and isolation.

Dependency Surface

Detected Declarations

Annotated Snippet

struct memregion_info {
	int target_node;
	struct range range;
};

#ifdef CONFIG_MEMREGION
int memregion_alloc(gfp_t gfp);
void memregion_free(int id);
#else
static inline int memregion_alloc(gfp_t gfp)
{
	return -ENOMEM;
}
static inline void memregion_free(int id)
{
}
#endif

/**
 * cpu_cache_invalidate_memregion - drop any CPU cached data for
 *     memregion
 * @start: start physical address of the target memory region.
 * @len: length of the target memory region. -1 for all the regions of
 *       the target type.
 *
 * Perform cache maintenance after a memory event / operation that
 * changes the contents of physical memory in a cache-incoherent manner.
 * For example, device memory technologies like NVDIMM and CXL have
 * device secure erase, and dynamic region provision that can replace
 * the memory mapped to a given physical address.
 *
 * Limit the functionality to architectures that have an efficient way
 * to writeback and invalidate potentially terabytes of address space at
 * once.  Note that this routine may or may not write back any dirty
 * contents while performing the invalidation. It is only exported for
 * the explicit usage of the NVDIMM and CXL modules in the 'DEVMEM'
 * symbol namespace on bare platforms.
 *
 * Returns 0 on success or negative error code on a failure to perform
 * the cache maintenance.
 */
#ifdef CONFIG_ARCH_HAS_CPU_CACHE_INVALIDATE_MEMREGION
int cpu_cache_invalidate_memregion(phys_addr_t start, size_t len);
bool cpu_cache_has_invalidate_memregion(void);
#else
static inline bool cpu_cache_has_invalidate_memregion(void)
{
	return false;
}

static inline int cpu_cache_invalidate_memregion(phys_addr_t start, size_t len)
{
	WARN_ON_ONCE("CPU cache invalidation required");
	return -ENXIO;
}
#endif

static inline int cpu_cache_invalidate_all(void)
{
	return cpu_cache_invalidate_memregion(0, -1);
}

#endif /* _MEMREGION_H_ */

Annotation

Implementation Notes