/*-
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 *
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 *       notice, this list of conditions and the following disclaimer.
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 *       from this software without specific prior written permission.
 *
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 *   OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#include "spdk/stdinc.h"
#include "spdk/ftl.h"

#include "ftl_io.h"
#include "ftl_core.h"
#include "ftl_rwb.h"
#include "ftl_band.h"

size_t
ftl_io_inc_req(struct ftl_io *io)
{
	struct ftl_band *band = io->band;

	if (io->type != FTL_IO_READ && io->type != FTL_IO_ERASE) {
		ftl_band_acquire_md(band);
	}

	__atomic_fetch_add(&io->dev->num_inflight, 1, __ATOMIC_SEQ_CST);

	return ++io->req_cnt;
}

size_t
ftl_io_dec_req(struct ftl_io *io)
{
	struct ftl_band *band = io->band;
	unsigned long num_inflight __attribute__((unused));

	if (io->type != FTL_IO_READ && io->type != FTL_IO_ERASE) {
		ftl_band_release_md(band);
	}

	num_inflight = __atomic_fetch_sub(&io->dev->num_inflight, 1, __ATOMIC_SEQ_CST);

	assert(num_inflight > 0);
	assert(io->req_cnt > 0);

	return --io->req_cnt;
}

struct iovec *
ftl_io_iovec(struct ftl_io *io)
{
	if (io->iov_cnt > 1) {
		return io->iovs;
	} else {
		return &io->iov;
	}
}

uint64_t
ftl_io_current_lba(struct ftl_io *io)
{
	if (io->flags & FTL_IO_VECTOR_LBA) {
		return io->lbas[io->pos];
	} else {
		return io->lba + io->pos;
	}
}

void
ftl_io_update_iovec(struct ftl_io *io, size_t lbk_cnt)
{
	struct iovec *iov = ftl_io_iovec(io);
	size_t iov_lbks;

	while (lbk_cnt > 0) {
		assert(io->iov_pos < io->iov_cnt);
		iov_lbks = iov[io->iov_pos].iov_len / PAGE_SIZE;

		if (io->iov_off + lbk_cnt < iov_lbks) {
			io->iov_off += lbk_cnt;
			break;
		}

		assert(iov_lbks > io->iov_off);
		lbk_cnt -= (iov_lbks - io->iov_off);
		io->iov_off = 0;
		io->iov_pos++;
	}
}

size_t
ftl_iovec_num_lbks(struct iovec *iov, size_t iov_cnt)
{
	size_t lbks = 0, i = 0;

	for (; i < iov_cnt; ++i) {
		lbks += iov[i].iov_len / PAGE_SIZE;
	}

	return lbks;
}

void *
ftl_io_iovec_addr(struct ftl_io *io)
{
	assert(io->iov_pos < io->iov_cnt);
	assert(io->iov_off * PAGE_SIZE < ftl_io_iovec(io)[io->iov_pos].iov_len);

	return (char *)ftl_io_iovec(io)[io->iov_pos].iov_base +
	       io->iov_off * PAGE_SIZE;
}

size_t
ftl_io_iovec_len_left(struct ftl_io *io)
{
	struct iovec *iov = ftl_io_iovec(io);
	return iov[io->iov_pos].iov_len / PAGE_SIZE - io->iov_off;
}

int
ftl_io_init_iovec(struct ftl_io *io, void *buf,
		  size_t iov_cnt, size_t req_size)
{
	struct iovec *iov;
	size_t i;

	if (iov_cnt > 1) {
		iov = io->iovs = calloc(iov_cnt, sizeof(*iov));
		if (!iov) {
			return -ENOMEM;
		}
	} else {
		iov = &io->iov;
	}

	io->iov_pos = 0;
	io->iov_cnt = iov_cnt;
	for (i = 0; i < iov_cnt; ++i) {
		iov[i].iov_base = (char *)buf + i * req_size * PAGE_SIZE;
		iov[i].iov_len = req_size * PAGE_SIZE;
	}

	return 0;
}

static void
ftl_io_init(struct ftl_io *io, struct spdk_ftl_dev *dev,
	    spdk_ftl_fn fn, void *ctx, int flags, int type)
{
	io->flags |= flags | FTL_IO_INITIALIZED;
	io->type = type;
	io->dev = dev;
	io->lba = FTL_LBA_INVALID;
	io->cb.fn = fn;
	io->cb.ctx = ctx;
	io->trace = ftl_trace_alloc_id(dev);
}

struct ftl_io *
ftl_io_init_internal(const struct ftl_io_init_opts *opts)
{
	struct ftl_io *io = opts->io;
	struct spdk_ftl_dev *dev = opts->dev;

	if (!io) {
		io = ftl_io_alloc(dev->ioch);
		if (!io) {
			return NULL;
		}
	}

	ftl_io_clear(io);
	ftl_io_init(io, dev, opts->fn, io, opts->flags | FTL_IO_INTERNAL, opts->type);

	io->lbk_cnt = opts->iov_cnt * opts->req_size;
	io->rwb_batch = opts->rwb_batch;
	io->band = opts->band;
	io->md = io->md;

	if (ftl_io_init_iovec(io, opts->data, opts->iov_cnt, opts->req_size)) {
		if (!opts->io) {
			ftl_io_free(io);
		}
		return NULL;
	}

	return io;
}

struct ftl_io *
ftl_io_rwb_init(struct spdk_ftl_dev *dev, struct ftl_band *band,
		struct ftl_rwb_batch *batch, spdk_ftl_fn cb)
{
	struct ftl_io_init_opts opts = {
		.dev		= dev,
		.io		= NULL,
		.rwb_batch	= batch,
		.band		= band,
		.size		= sizeof(struct ftl_io),
		.flags		= 0,
		.type		= FTL_IO_WRITE,
		.iov_cnt	= 1,
		.req_size	= dev->xfer_size,
		.fn		= cb,
		.data		= ftl_rwb_batch_get_data(batch),
		.md		= ftl_rwb_batch_get_md(batch),
	};

	return ftl_io_init_internal(&opts);
}

struct ftl_io *
ftl_io_erase_init(struct ftl_band *band, size_t lbk_cnt, spdk_ftl_fn cb)
{
	struct ftl_io *io;
	struct ftl_io_init_opts opts = {
		.dev		= band->dev,
		.io		= NULL,
		.rwb_batch	= NULL,
		.band		= band,
		.size		= sizeof(struct ftl_io),
		.flags		= FTL_IO_PPA_MODE,
		.type		= FTL_IO_ERASE,
		.iov_cnt	= 0,
		.req_size	= 1,
		.fn		= cb,
		.data		= NULL,
		.md		= NULL,
	};

	io = ftl_io_init_internal(&opts);
	io->lbk_cnt = lbk_cnt;

	return io;
}

void
ftl_io_user_init(struct spdk_ftl_dev *dev, struct ftl_io *io, uint64_t lba, size_t lbk_cnt,
		 struct iovec *iov, size_t iov_cnt,
		 spdk_ftl_fn cb_fn, void *cb_arg, int type)
{
	if (io->flags & FTL_IO_INITIALIZED) {
		return;
	}

	ftl_io_init(io, dev, cb_fn, cb_arg, 0, type);

	io->lba = lba;
	io->lbk_cnt = lbk_cnt;
	io->iov_cnt = iov_cnt;

	if (iov_cnt > 1) {
		io->iovs = iov;
	} else {
		io->iov = *iov;
	}

	ftl_trace_lba_io_init(io->dev, io);
}

void
ftl_io_complete(struct ftl_io *io)
{
	int keep_alive = io->flags & FTL_IO_KEEP_ALIVE;

	io->flags &= ~FTL_IO_INITIALIZED;
	io->cb.fn(io->cb.ctx, io->status);

	if (!keep_alive) {
		ftl_io_free(io);
	}
}

void
ftl_io_process_error(struct ftl_io *io, const struct spdk_nvme_cpl *status)
{
	io->status = -EIO;

	/* TODO: add error handling for specifc cases */
	if (status->status.sct == SPDK_NVME_SCT_MEDIA_ERROR &&
	    status->status.sc == SPDK_OCSSD_SC_READ_HIGH_ECC) {
		io->status = 0;
	}
}

void *
ftl_io_get_md(const struct ftl_io *io)
{
	if (!io->md) {
		return NULL;
	}

	return (char *)io->md + io->pos * FTL_BLOCK_SIZE;
}

struct ftl_io *
ftl_io_alloc(struct spdk_io_channel *ch)
{
	struct ftl_io *io;
	struct ftl_io_channel *ioch = spdk_io_channel_get_ctx(ch);

	io = spdk_mempool_get(ioch->io_pool);
	if (!io) {
		return NULL;
	}

	memset(io, 0, ioch->elem_size);
	io->ch = ch;
	return io;
}

void
ftl_io_reinit(struct ftl_io *io, spdk_ftl_fn fn, void *ctx, int flags, int type)
{
	ftl_io_clear(io);
	ftl_io_init(io, io->dev, fn, ctx, flags, type);
}

void
ftl_io_clear(struct ftl_io *io)
{
	io->pos = 0;
	io->req_cnt = 0;
	io->iov_pos = 0;
	io->iov_off = 0;
	io->flags = 0;
	io->rwb_batch = NULL;
	io->band = NULL;
}

void
ftl_io_free(struct ftl_io *io)
{
	struct ftl_io_channel *ioch;

	if (!io) {
		return;
	}

	if ((io->flags & FTL_IO_INTERNAL) && io->iov_cnt > 1) {
		free(io->iovs);
	}

	ioch = spdk_io_channel_get_ctx(io->ch);
	spdk_mempool_put(ioch->io_pool, io);
}