/*-
 * Copyright (c) 2012 Chelsio Communications, Inc.
 * All rights reserved.
 *
 * Chelsio T5xx iSCSI driver
 * cxgbei_ulp2_ddp.c: Chelsio iSCSI DDP Manager.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
 * $FreeBSD$
 *
 */

#ifndef __CXGBEI_ULP2_DDP_H__
#define __CXGBEI_ULP2_DDP_H__

#define CXGBEI_PAGE_MASK	(~(PAGE_SIZE-1))
#define DDP_THRESHOLD		2048

/*
 * cxgbei ddp tag are 32 bits, it consists of reserved bits used by h/w and
 * non-reserved bits that can be used by the iscsi s/w.
 * The reserved bits are identified by the rsvd_bits and rsvd_shift fields
 * in struct cxgbei_ulp2_tag_format.
 *
 * The upper most reserved bit can be used to check if a tag is ddp tag or not:
 * 	if the bit is 0, the tag is a valid ddp tag
 */

/*
 * cxgbei_ulp2_is_ddp_tag - check if a given tag is a hw/ddp tag
 * @tformat: tag format information
 * @tag: tag to be checked
 *
 * return true if the tag is a ddp tag, false otherwise.
 */
static inline int
cxgbei_ulp2_is_ddp_tag(struct cxgbei_ulp2_tag_format *tformat, uint32_t tag)
{

	return (!(tag & (1 << (tformat->rsvd_bits + tformat->rsvd_shift - 1))));
}

/*
 * cxgbei_ulp2_sw_tag_usable - check if s/w tag has enough bits left for hw bits
 * @tformat: tag format information
 * @sw_tag: s/w tag to be checked
 *
 * return true if the tag can be used for hw ddp tag, false otherwise.
 */
static inline int
cxgbei_ulp2_sw_tag_usable(struct cxgbei_ulp2_tag_format *tformat,
    uint32_t sw_tag)
{

	return (1);	/* XXXNP: huh? */

	sw_tag >>= (32 - tformat->rsvd_bits + tformat->rsvd_shift);
	return !sw_tag;
}

/*
 * cxgbei_ulp2_set_non_ddp_tag - mark a given s/w tag as an invalid ddp tag
 * @tformat: tag format information
 * @sw_tag: s/w tag to be checked
 *
 * insert 1 at the upper most reserved bit to mark it as an invalid ddp tag.
 */
static inline uint32_t
cxgbei_ulp2_set_non_ddp_tag(struct cxgbei_ulp2_tag_format *tformat,
					 uint32_t sw_tag)
{
	uint32_t rsvd_bits = tformat->rsvd_bits + tformat->rsvd_shift;
	if (sw_tag) {
                u32 v1 = sw_tag & ((1 << (rsvd_bits - 1)) - 1);
                u32 v2 = (sw_tag >> (rsvd_bits - 1)) << rsvd_bits;
                return v2 | (1 << (rsvd_bits - 1)) | v1;
        }

	return sw_tag | (1 << (rsvd_bits - 1)) ;
}

struct dma_segments {
	bus_dmamap_t bus_map;
	bus_addr_t phys_addr;
};
/*
 * struct cxgbei_ulp2_gather_list - cxgbei direct data placement memory
 *
 * @tag:	ddp tag
 * @length:	total data buffer length
 * @offset:	initial offset to the 1st page
 * @nelem:	# of pages
 * @pages:	page pointers
 * @phys_addr:	physical address
 */
struct cxgbei_ulp2_gather_list {
	uint32_t tag;
	uint32_t tid;
	uint32_t port_id;
	void *egress_dev;
	unsigned int length;
	unsigned int offset;
	unsigned int nelem;
	bus_size_t	mapsize;
	bus_dmamap_t	bus_map;
	bus_dma_segment_t	*segments;
	void **pages;
	struct dma_segments dma_sg[0];
};

#define IPPOD_SIZE		sizeof(struct cxgbei_ulp2_pagepod) /* 64 */
#define IPPOD_SIZE_SHIFT	6

#define IPPOD_COLOR_SHIFT	0
#define IPPOD_COLOR_SIZE	6
#define IPPOD_COLOR_MASK	((1 << IPPOD_COLOR_SIZE) - 1)

#define IPPOD_IDX_SHIFT		IPPOD_COLOR_SIZE
#define IPPOD_IDX_MAX_SIZE	24

#define S_IPPOD_TID    0
#define M_IPPOD_TID    0xFFFFFF
#define V_IPPOD_TID(x) ((x) << S_IPPOD_TID)

#define S_IPPOD_VALID    24
#define V_IPPOD_VALID(x) ((x) << S_IPPOD_VALID)
#define F_IPPOD_VALID    V_IPPOD_VALID(1U)

#define S_IPPOD_COLOR    0
#define M_IPPOD_COLOR    0x3F
#define V_IPPOD_COLOR(x) ((x) << S_IPPOD_COLOR)

#define S_IPPOD_TAG    6
#define M_IPPOD_TAG    0xFFFFFF
#define V_IPPOD_TAG(x) ((x) << S_IPPOD_TAG)

#define S_IPPOD_PGSZ    30
#define M_IPPOD_PGSZ    0x3
#define V_IPPOD_PGSZ(x) ((x) << S_IPPOD_PGSZ)

static inline uint32_t
cxgbei_ulp2_ddp_tag_base(u_int idx, u_char *colors,
    struct cxgbei_ulp2_tag_format *tformat, uint32_t sw_tag)
{
	if (__predict_false(++colors[idx] == 1 << IPPOD_IDX_SHIFT))
		colors[idx] = 0;

	sw_tag <<= tformat->rsvd_bits + tformat->rsvd_shift;

	return (sw_tag | idx << IPPOD_IDX_SHIFT | colors[idx]);
}

#define ISCSI_PDU_NONPAYLOAD_LEN	312 /* bhs(48) + ahs(256) + digest(8) */

/*
 * align pdu size to multiple of 512 for better performance
 */
#define cxgbei_align_pdu_size(n) do { n = (n) & (~511); } while (0)

#define ULP2_MAX_PKT_SIZE	16224
#define ULP2_MAX_PDU_PAYLOAD	(ULP2_MAX_PKT_SIZE - ISCSI_PDU_NONPAYLOAD_LEN)
#define IPPOD_PAGES_MAX		4
#define IPPOD_PAGES_SHIFT	2	/* 4 pages per pod */

/*
 * struct pagepod_hdr, pagepod - pagepod format
 */
struct cxgbei_ulp2_pagepod_hdr {
	uint32_t vld_tid;
	uint32_t pgsz_tag_clr;
	uint32_t maxoffset;
	uint32_t pgoffset;
	uint64_t rsvd;
};

struct cxgbei_ulp2_pagepod {
	struct cxgbei_ulp2_pagepod_hdr hdr;
	uint64_t addr[IPPOD_PAGES_MAX + 1];
};

int cxgbei_ulp2_ddp_tag_reserve(struct cxgbei_data *, void *, unsigned int,
    struct cxgbei_ulp2_tag_format *, uint32_t *,
    struct cxgbei_ulp2_gather_list *, int , int );
void cxgbei_ulp2_ddp_tag_release(struct cxgbei_data *, uint32_t,
    struct icl_cxgbei_conn *);

struct cxgbei_ulp2_gather_list *cxgbei_ulp2_ddp_make_gl_from_iscsi_sgvec(u_int,
    struct cxgbei_sgl *, u_int, struct cxgbei_data *, int);
void cxgbei_ulp2_ddp_release_gl(struct cxgbei_data *,
    struct cxgbei_ulp2_gather_list *);

int cxgbei_ulp2_ddp_find_page_index(u_long);
int cxgbei_ulp2_adapter_ddp_info(struct cxgbei_data *,
    struct cxgbei_ulp2_tag_format *);

void cxgbei_ddp_cleanup(struct cxgbei_data *);
#endif