Spdk/include/spdk/ftl.h

/*-
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 *
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 *       notice, this list of conditions and the following disclaimer.
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 *       contributors may be used to endorse or promote products derived
 *       from this software without specific prior written permission.
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#ifndef SPDK_FTL_H
#define SPDK_FTL_H

#include <spdk/stdinc.h>
#include <spdk/nvme.h>
#include <spdk/nvme_ocssd.h>
#include <spdk/uuid.h>
#include <spdk/thread.h>

struct spdk_ftl_dev;

/* Limit thresholds */
enum {
	SPDK_FTL_LIMIT_CRIT,
	SPDK_FTL_LIMIT_HIGH,
	SPDK_FTL_LIMIT_LOW,
	SPDK_FTL_LIMIT_START,
	SPDK_FTL_LIMIT_MAX
};

struct spdk_ftl_limit {
	/* Threshold from which the limiting starts */
	size_t					thld;

	/* Limit percentage */
	size_t					limit;
};

struct spdk_ftl_conf {
	/* Number of reserved addresses not exposed to the user */
	size_t					lba_rsvd;

	/* Write buffer size */
	size_t					rwb_size;

	/* Threshold for opening new band */
	size_t					band_thld;

	/* Trace enabled flag */
	int					trace;

	/* Trace file name */
	const char				*trace_path;

	/* Maximum IO depth per band relocate */
	size_t					max_reloc_qdepth;

	/* Maximum active band relocates */
	size_t					max_active_relocs;

	/* IO pool size per user thread */
	size_t					user_io_pool_size;

	struct {
		/* Lowest percentage of invalid lbks for a band to be defragged */
		size_t				invalid_thld;

		/* User writes limits */
		struct spdk_ftl_limit		limits[SPDK_FTL_LIMIT_MAX];
	} defrag;
};

/* Range of parallel units (inclusive) */
struct spdk_ftl_punit_range {
	unsigned int				begin;
	unsigned int				end;
};

enum spdk_ftl_mode {
	/* Create new device */
	SPDK_FTL_MODE_CREATE = (1 << 0),
};

struct spdk_ftl_dev_init_opts {
	/* NVMe controller */
	struct spdk_nvme_ctrlr			*ctrlr;
	/* Controller's transport ID */
	struct spdk_nvme_transport_id		trid;

	/* Thread responsible for core tasks execution */
	struct spdk_thread			*core_thread;
	/* Thread responsible for read requests */
	struct spdk_thread			*read_thread;

	/* Device's config */
	struct spdk_ftl_conf			*conf;
	/* Device's name */
	const char				*name;
	/* Parallel unit range */
	struct spdk_ftl_punit_range		range;
	/* Mode flags */
	unsigned int				mode;
	/* Device UUID (valid when restoring device from disk) */
	struct spdk_uuid			uuid;
};

struct spdk_ftl_attrs {
	/* Device's UUID */
	struct spdk_uuid			uuid;
	/* Parallel unit range */
	struct spdk_ftl_punit_range		range;
	/* Number of logical blocks */
	uint64_t				lbk_cnt;
	/* Logical block size */
	size_t					lbk_size;
};

struct ftl_module_init_opts {
	/* Thread on which to poll for ANM events */
	struct spdk_thread			*anm_thread;
};

typedef void (*spdk_ftl_fn)(void *, int);
typedef void (*spdk_ftl_init_fn)(struct spdk_ftl_dev *, void *, int);

/**
 * Initialize the FTL module.
 *
 * \param opts module configuration
 * \param cb callback function to call when the module is initialized
 * \param cb_arg callback's argument
 *
 * \return 0 if successfully started initialization, negative values if
 * resources could not be allocated.
 */
int spdk_ftl_module_init(const struct ftl_module_init_opts *opts, spdk_ftl_fn cb, void *cb_arg);

/**
 * Deinitialize the FTL module. All FTL devices have to be unregistered prior to
 * calling this function.
 *
 * \param cb callback function to call when the deinitialization is completed
 * \param cb_arg callback's argument
 *
 * \return 0 if successfully scheduled deinitialization, negative errno
 * otherwise.
 */
int spdk_ftl_module_fini(spdk_ftl_fn cb, void *cb_arg);

/**
 * Initialize the FTL on given NVMe device and parallel unit range.
 *
 * Covers the following:
 * - initialize and register NVMe ctrlr,
 * - retrieve geometry and check if the device has proper configuration,
 * - allocate buffers and resources,
 * - initialize internal structures,
 * - initialize internal thread(s),
 * - restore or create L2P table.
 *
 * \param opts configuration for new device
 * \param cb callback function to call when the device is created
 * \param cb_arg callback's argument
 *
 * \return 0 if initialization was started successfully, negative errno otherwise.
 */
int spdk_ftl_dev_init(const struct spdk_ftl_dev_init_opts *opts, spdk_ftl_init_fn cb, void *cb_arg);

/**
 * Deinitialize and free given device.
 *
 * \param dev device
 * \param cb callback function to call when the device is freed
 * \param cb_arg callback's argument
 *
 * \return 0 if successfully scheduled free, negative errno otherwise.
 */
int spdk_ftl_dev_free(struct spdk_ftl_dev *dev, spdk_ftl_fn cb, void *cb_arg);

/**
 * Initialize FTL configuration structure with default values.
 *
 * \param conf FTL configuration to initialize
 */
void spdk_ftl_conf_init_defaults(struct spdk_ftl_conf *conf);

/**
 * Retrieve device’s attributes.
 *
 * \param dev device
 * \param attr Attribute structure to fill
 *
 * \return 0 if successfully initialized, negated EINVAL otherwise.
 */
int spdk_ftl_dev_get_attrs(const struct spdk_ftl_dev *dev, struct spdk_ftl_attrs *attr);

/**
 * Submits a read to the specified device.
 *
 * \param dev Device
 * \param ch I/O channel
 * \param lba Starting LBA to read the data
 * \param lba_cnt Number of sectors to read
 * \param iov Single IO vector or pointer to IO vector table
 * \param iov_cnt Number of IO vectors
 * \param cb_fn Callback function to invoke when the I/O is completed
 * \param cb_arg Argument to pass to the callback function
 *
 * \return 0 if successfully submitted, negated EINVAL otherwise.
 */
int spdk_ftl_read(struct spdk_ftl_dev *dev, struct spdk_io_channel *ch, uint64_t lba,
		  size_t lba_cnt,
		  struct iovec *iov, size_t iov_cnt, spdk_ftl_fn cb_fn, void *cb_arg);

/**
 * Submits a write to the specified device.
 *
 * \param dev Device
 * \param ch I/O channel
 * \param lba Starting LBA to write the data
 * \param lba_cnt Number of sectors to write
 * \param iov Single IO vector or pointer to IO vector table
 * \param iov_cnt Number of IO vectors
 * \param cb_fn Callback function to invoke when the I/O is completed
 * \param cb_arg Argument to pass to the callback function
 *
 * \return 0 if successfully submitted, negative values otherwise.
 */
int spdk_ftl_write(struct spdk_ftl_dev *dev, struct spdk_io_channel *ch, uint64_t lba,
		   size_t lba_cnt,
		   struct iovec *iov, size_t iov_cnt, spdk_ftl_fn cb_fn, void *cb_arg);

/**
 * Submits a flush request to the specified device.
 *
 * \param dev device
 * \param cb_fn Callback function to invoke when all prior IOs have been completed
 * \param cb_arg Argument to pass to the callback function
 *
 * \return 0 if successfully submitted, negated EINVAL or ENOMEM otherwise.
 */
int spdk_ftl_flush(struct spdk_ftl_dev *dev, spdk_ftl_fn cb_fn, void *cb_arg);

#endif /* SPDK_FTL_H */