struct zpool;
-/*
- * Control how a handle is mapped. It will be ignored if the
- * implementation does not support it. Its use is optional.
- * Note that this does not refer to memory protection, it
- * refers to how the memory will be copied in/out if copying
- * is necessary during mapping; read-write is the safest as
- * it copies the existing memory in on map, and copies the
- * changed memory back out on unmap. Write-only does not copy
- * in the memory and should only be used for initialization.
- * If in doubt, use ZPOOL_MM_DEFAULT which is read-write.
- */
-enum zpool_mapmode {
- ZPOOL_MM_RW, /* normal read-write mapping */
- ZPOOL_MM_RO, /* read-only (no copy-out at unmap time) */
- ZPOOL_MM_WO, /* write-only (no copy-in at map time) */
-
- ZPOOL_MM_DEFAULT = ZPOOL_MM_RW
-};
-
bool zpool_has_pool(char *type);
struct zpool *zpool_create_pool(const char *type, const char *name, gfp_t gfp);
void zpool_free(struct zpool *pool, unsigned long handle);
-void *zpool_map_handle(struct zpool *pool, unsigned long handle,
- enum zpool_mapmode mm);
-
-void zpool_unmap_handle(struct zpool *pool, unsigned long handle);
-
-
void *zpool_obj_read_begin(struct zpool *zpool, unsigned long handle,
void *local_copy);
unsigned long *handle);
void (*free)(void *pool, unsigned long handle);
- bool sleep_mapped;
- void *(*map)(void *pool, unsigned long handle,
- enum zpool_mapmode mm);
- void (*unmap)(void *pool, unsigned long handle);
-
void *(*obj_read_begin)(void *pool, unsigned long handle,
void *local_copy);
void (*obj_read_end)(void *pool, unsigned long handle,
zpool->driver->free(zpool->pool, handle);
}
-/**
- * zpool_map_handle() - Map a previously allocated handle into memory
- * @zpool: The zpool that the handle was allocated from
- * @handle: The handle to map
- * @mapmode: How the memory should be mapped
- *
- * This maps a previously allocated handle into memory. The @mapmode
- * param indicates to the implementation how the memory will be
- * used, i.e. read-only, write-only, read-write. If the
- * implementation does not support it, the memory will be treated
- * as read-write.
- *
- * This may hold locks, disable interrupts, and/or preemption,
- * and the zpool_unmap_handle() must be called to undo those
- * actions. The code that uses the mapped handle should complete
- * its operations on the mapped handle memory quickly and unmap
- * as soon as possible. As the implementation may use per-cpu
- * data, multiple handles should not be mapped concurrently on
- * any cpu.
- *
- * Returns: A pointer to the handle's mapped memory area.
- */
-void *zpool_map_handle(struct zpool *zpool, unsigned long handle,
- enum zpool_mapmode mapmode)
-{
- return zpool->driver->map(zpool->pool, handle, mapmode);
-}
-
-/**
- * zpool_unmap_handle() - Unmap a previously mapped handle
- * @zpool: The zpool that the handle was allocated from
- * @handle: The handle to unmap
- *
- * This unmaps a previously mapped handle. Any locks or other
- * actions that the implementation took in zpool_map_handle()
- * will be undone here. The memory area returned from
- * zpool_map_handle() should no longer be used after this.
- */
-void zpool_unmap_handle(struct zpool *zpool, unsigned long handle)
-{
- zpool->driver->unmap(zpool->pool, handle);
-}
-
/**
* zpool_obj_read_begin() - Start reading from a previously allocated handle.
* @zpool: The zpool that the handle was allocated from
return zpool->driver->total_pages(zpool->pool);
}
-/**
- * zpool_can_sleep_mapped - Test if zpool can sleep when do mapped.
- * @zpool: The zpool to test
- *
- * Some allocators enter non-preemptible context in ->map() callback (e.g.
- * disable pagefaults) and exit that context in ->unmap(), which limits what
- * we can do with the mapped object. For instance, we cannot wait for
- * asynchronous crypto API to decompress such an object or take mutexes
- * since those will call into the scheduler. This function tells us whether
- * we use such an allocator.
- *
- * Returns: true if zpool can sleep; false otherwise.
- */
-bool zpool_can_sleep_mapped(struct zpool *zpool)
-{
- return zpool->driver->sleep_mapped;
-}
-
MODULE_AUTHOR("Dan Streetman <ddstreet@ieee.org>");
MODULE_DESCRIPTION("Common API for compressed memory storage");
zs_free(pool, handle);
}
-static void *zs_zpool_map(void *pool, unsigned long handle,
- enum zpool_mapmode mm)
-{
- enum zs_mapmode zs_mm;
-
- switch (mm) {
- case ZPOOL_MM_RO:
- zs_mm = ZS_MM_RO;
- break;
- case ZPOOL_MM_WO:
- zs_mm = ZS_MM_WO;
- break;
- case ZPOOL_MM_RW:
- default:
- zs_mm = ZS_MM_RW;
- break;
- }
-
- return zs_map_object(pool, handle, zs_mm);
-}
-static void zs_zpool_unmap(void *pool, unsigned long handle)
-{
- zs_unmap_object(pool, handle);
-}
-
static void *zs_zpool_obj_read_begin(void *pool, unsigned long handle,
void *local_copy)
{
.malloc_support_movable = true,
.malloc = zs_zpool_malloc,
.free = zs_zpool_free,
- .map = zs_zpool_map,
- .unmap = zs_zpool_unmap,
.obj_read_begin = zs_zpool_obj_read_begin,
.obj_read_end = zs_zpool_obj_read_end,
.obj_write = zs_zpool_obj_write,
projects / thirdparty / linux.git / commitdiff
