cxgb4: add iSCSI DDP page pod manager

add files for common page pod manager,
both iSCSI initiator and target ULDs will
use common ppod manager for DDP.
Signed-off-by: Varun Prakash <varun@chelsio.com>
Acked-by: Hariprasad Shenai <hariprasad@chelsio.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

drivers/net/ethernet/chelsio/cxgb4/cxgb4_ppm.h

+/*
+ * cxgb4_ppm.h: Chelsio common library for T4/T5 iSCSI ddp operation
+ *
+ * Copyright (c) 2016 Chelsio Communications, Inc. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * Written by: Karen Xie (kxie@chelsio.com)
+ */
+
+#ifndef	__CXGB4PPM_H__
+#define	__CXGB4PPM_H__
+
+#include <linux/kernel.h>
+#include <linux/errno.h>
+#include <linux/types.h>
+#include <linux/debugfs.h>
+#include <linux/list.h>
+#include <linux/netdevice.h>
+#include <linux/scatterlist.h>
+#include <linux/skbuff.h>
+#include <linux/vmalloc.h>
+#include <linux/bitmap.h>
+
+struct cxgbi_pagepod_hdr {
+	u32 vld_tid;
+	u32 pgsz_tag_clr;
+	u32 max_offset;
+	u32 page_offset;
+	u64 rsvd;
+};
+
+#define PPOD_PAGES_MAX			4
+struct cxgbi_pagepod {
+	struct cxgbi_pagepod_hdr hdr;
+	u64 addr[PPOD_PAGES_MAX + 1];
+};
+
+/* ddp tag format
+ * for a 32-bit tag:
+ * bit #
+ * 31 .....   .....  0
+ *     X   Y...Y Z...Z, where
+ *     ^   ^^^^^ ^^^^
+ *     |   |      |____ when ddp bit = 0: color bits
+ *     |   |
+ *     |   |____ when ddp bit = 0: idx into the ddp memory region
+ *     |
+ *     |____ ddp bit: 0 - ddp tag, 1 - non-ddp tag
+ *
+ *  [page selector:2] [sw/free bits] [0] [idx] [color:6]
+ */
+
+#define DDP_PGIDX_MAX		4
+#define DDP_PGSZ_BASE_SHIFT	12	/* base page 4K */
+
+struct cxgbi_task_tag_info {
+	unsigned char flags;
+#define CXGBI_PPOD_INFO_FLAG_VALID	0x1
+#define CXGBI_PPOD_INFO_FLAG_MAPPED	0x2
+	unsigned char cid;
+	unsigned short pg_shift;
+	unsigned int npods;
+	unsigned int idx;
+	unsigned int tag;
+	struct cxgbi_pagepod_hdr hdr;
+	int nents;
+	int nr_pages;
+	struct scatterlist *sgl;
+};
+
+struct cxgbi_tag_format {
+	unsigned char pgsz_order[DDP_PGIDX_MAX];
+	unsigned char pgsz_idx_dflt;
+	unsigned char free_bits:4;
+	unsigned char color_bits:4;
+	unsigned char idx_bits;
+	unsigned char rsvd_bits;
+	unsigned int  no_ddp_mask;
+	unsigned int  idx_mask;
+	unsigned int  color_mask;
+	unsigned int  idx_clr_mask;
+	unsigned int  rsvd_mask;
+};
+
+struct cxgbi_ppod_data {
+	unsigned char pg_idx:2;
+	unsigned char color:6;
+	unsigned char chan_id;
+	unsigned short npods;
+	unsigned long caller_data;
+};
+
+/* per cpu ppm pool */
+struct cxgbi_ppm_pool {
+	unsigned int base;		/* base index */
+	unsigned int next;		/* next possible free index */
+	spinlock_t lock;		/* ppm pool lock */
+	unsigned long bmap[0];
+} ____cacheline_aligned_in_smp;
+
+struct cxgbi_ppm {
+	struct kref refcnt;
+	struct net_device *ndev;	/* net_device, 1st port */
+	struct pci_dev *pdev;
+	void *lldev;
+	void **ppm_pp;
+	struct cxgbi_tag_format tformat;
+	unsigned int ppmax;
+	unsigned int llimit;
+	unsigned int base_idx;
+
+	unsigned int pool_rsvd;
+	unsigned int pool_index_max;
+	struct cxgbi_ppm_pool __percpu *pool;
+	/* map lock */
+	spinlock_t map_lock;		/* ppm map lock */
+	unsigned int bmap_index_max;
+	unsigned int next;
+	unsigned long *ppod_bmap;
+	struct cxgbi_ppod_data ppod_data[0];
+};
+
+#define DDP_THRESHOLD		512
+
+#define PPOD_PAGES_SHIFT	2       /*  4 pages per pod */
+
+#define IPPOD_SIZE               sizeof(struct cxgbi_pagepod)  /*  64 */
+#define PPOD_SIZE_SHIFT         6
+
+/* page pods are allocated in groups of this size (must be power of 2) */
+#define PPOD_CLUSTER_SIZE	16U
+
+#define ULPMEM_DSGL_MAX_NPPODS	16	/*  1024/PPOD_SIZE */
+#define ULPMEM_IDATA_MAX_NPPODS	3	/* (PPOD_SIZE * 3 + ulptx hdr) < 256B */
+#define PCIE_MEMWIN_MAX_NPPODS	16	/*  1024/PPOD_SIZE */
+
+#define PPOD_COLOR_SHIFT	0
+#define PPOD_COLOR(x)		((x) << PPOD_COLOR_SHIFT)
+
+#define PPOD_IDX_SHIFT          6
+#define PPOD_IDX_MAX_SIZE       24
+
+#define PPOD_TID_SHIFT		0
+#define PPOD_TID(x)		((x) << PPOD_TID_SHIFT)
+
+#define PPOD_TAG_SHIFT		6
+#define PPOD_TAG(x)		((x) << PPOD_TAG_SHIFT)
+
+#define PPOD_VALID_SHIFT	24
+#define PPOD_VALID(x)		((x) << PPOD_VALID_SHIFT)
+#define PPOD_VALID_FLAG		PPOD_VALID(1U)
+
+#define PPOD_PI_EXTRACT_CTL_SHIFT	31
+#define PPOD_PI_EXTRACT_CTL(x)		((x) << PPOD_PI_EXTRACT_CTL_SHIFT)
+#define PPOD_PI_EXTRACT_CTL_FLAG	V_PPOD_PI_EXTRACT_CTL(1U)
+
+#define PPOD_PI_TYPE_SHIFT		29
+#define PPOD_PI_TYPE_MASK		0x3
+#define PPOD_PI_TYPE(x)			((x) << PPOD_PI_TYPE_SHIFT)
+
+#define PPOD_PI_CHECK_CTL_SHIFT		27
+#define PPOD_PI_CHECK_CTL_MASK		0x3
+#define PPOD_PI_CHECK_CTL(x)		((x) << PPOD_PI_CHECK_CTL_SHIFT)
+
+#define PPOD_PI_REPORT_CTL_SHIFT	25
+#define PPOD_PI_REPORT_CTL_MASK		0x3
+#define PPOD_PI_REPORT_CTL(x)		((x) << PPOD_PI_REPORT_CTL_SHIFT)
+
+static inline int cxgbi_ppm_is_ddp_tag(struct cxgbi_ppm *ppm, u32 tag)
+{
+	return !(tag & ppm->tformat.no_ddp_mask);
+}
+
+static inline int cxgbi_ppm_sw_tag_is_usable(struct cxgbi_ppm *ppm,
+					     u32 tag)
+{
+	/* the sw tag must be using <= 31 bits */
+	return !(tag & 0x80000000U);
+}
+
+static inline int cxgbi_ppm_make_non_ddp_tag(struct cxgbi_ppm *ppm,
+					     u32 sw_tag,
+					     u32 *final_tag)
+{
+	struct cxgbi_tag_format *tformat = &ppm->tformat;
+
+	if (!cxgbi_ppm_sw_tag_is_usable(ppm, sw_tag)) {
+		pr_info("sw_tag 0x%x NOT usable.\n", sw_tag);
+		return -EINVAL;
+	}
+
+	if (!sw_tag) {
+		*final_tag = tformat->no_ddp_mask;
+	} else {
+		unsigned int shift = tformat->idx_bits + tformat->color_bits;
+		u32 lower = sw_tag & tformat->idx_clr_mask;
+		u32 upper = (sw_tag >> shift) << (shift + 1);
+
+		*final_tag = upper | tformat->no_ddp_mask | lower;
+	}
+	return 0;
+}
+
+static inline u32 cxgbi_ppm_decode_non_ddp_tag(struct cxgbi_ppm *ppm,
+					       u32 tag)
+{
+	struct cxgbi_tag_format *tformat = &ppm->tformat;
+	unsigned int shift = tformat->idx_bits + tformat->color_bits;
+	u32 lower = tag & tformat->idx_clr_mask;
+	u32 upper = (tag >> tformat->rsvd_bits) << shift;
+
+	return upper | lower;
+}
+
+static inline u32 cxgbi_ppm_ddp_tag_get_idx(struct cxgbi_ppm *ppm,
+					    u32 ddp_tag)
+{
+	u32 hw_idx = (ddp_tag >> PPOD_IDX_SHIFT) &
+			ppm->tformat.idx_mask;
+
+	return hw_idx - ppm->base_idx;
+}
+
+static inline u32 cxgbi_ppm_make_ddp_tag(unsigned int hw_idx,
+					 unsigned char color)
+{
+	return (hw_idx << PPOD_IDX_SHIFT) | ((u32)color);
+}
+
+static inline unsigned long
+cxgbi_ppm_get_tag_caller_data(struct cxgbi_ppm *ppm,
+			      u32 ddp_tag)
+{
+	u32 idx = cxgbi_ppm_ddp_tag_get_idx(ppm, ddp_tag);
+
+	return ppm->ppod_data[idx].caller_data;
+}
+
+/* sw bits are the free bits */
+static inline int cxgbi_ppm_ddp_tag_update_sw_bits(struct cxgbi_ppm *ppm,
+						   u32 val, u32 orig_tag,
+						   u32 *final_tag)
+{
+	struct cxgbi_tag_format *tformat = &ppm->tformat;
+	u32 v = val >> tformat->free_bits;
+
+	if (v) {
+		pr_info("sw_bits 0x%x too large, avail bits %u.\n",
+			val, tformat->free_bits);
+		return -EINVAL;
+	}
+	if (!cxgbi_ppm_is_ddp_tag(ppm, orig_tag))
+		return -EINVAL;
+
+	*final_tag = (val << tformat->rsvd_bits) |
+		     (orig_tag & ppm->tformat.rsvd_mask);
+	return 0;
+}
+
+static inline void cxgbi_ppm_ppod_clear(struct cxgbi_pagepod *ppod)
+{
+	ppod->hdr.vld_tid = 0U;
+}
+
+static inline void cxgbi_tagmask_check(unsigned int tagmask,
+				       struct cxgbi_tag_format *tformat)
+{
+	unsigned int bits = fls(tagmask);
+
+	/* reserve top most 2 bits for page selector */
+	tformat->free_bits = 32 - 2 - bits;
+	tformat->rsvd_bits = bits;
+	tformat->color_bits = PPOD_IDX_SHIFT;
+	tformat->idx_bits = bits - 1 - PPOD_IDX_SHIFT;
+	tformat->no_ddp_mask = 1 << (bits - 1);
+	tformat->idx_mask = (1 << tformat->idx_bits) - 1;
+	tformat->color_mask = (1 << PPOD_IDX_SHIFT) - 1;
+	tformat->idx_clr_mask = (1 << (bits - 1)) - 1;
+	tformat->rsvd_mask = (1 << bits) - 1;
+
+	pr_info("ippm: tagmask 0x%x, rsvd %u=%u+%u+1, mask 0x%x,0x%x, "
+		"pg %u,%u,%u,%u.\n",
+		tagmask, tformat->rsvd_bits, tformat->idx_bits,
+		tformat->color_bits, tformat->no_ddp_mask, tformat->rsvd_mask,
+		tformat->pgsz_order[0], tformat->pgsz_order[1],
+		tformat->pgsz_order[2], tformat->pgsz_order[3]);
+}
+
+int cxgbi_ppm_find_page_index(struct cxgbi_ppm *ppm, unsigned long pgsz);
+void cxgbi_ppm_make_ppod_hdr(struct cxgbi_ppm *ppm, u32 tag,
+			     unsigned int tid, unsigned int offset,
+			     unsigned int length,
+			     struct cxgbi_pagepod_hdr *hdr);
+void cxgbi_ppm_ppod_release(struct cxgbi_ppm *, u32 idx);
+int cxgbi_ppm_ppods_reserve(struct cxgbi_ppm *, unsigned short nr_pages,
+			    u32 per_tag_pg_idx, u32 *ppod_idx, u32 *ddp_tag,
+			    unsigned long caller_data);
+int cxgbi_ppm_init(void **ppm_pp, struct net_device *, struct pci_dev *,
+		   void *lldev, struct cxgbi_tag_format *,
+		   unsigned int ppmax, unsigned int llimit,
+		   unsigned int start,
+		   unsigned int reserve_factor);
+int cxgbi_ppm_release(struct cxgbi_ppm *ppm);
+void cxgbi_tagmask_check(unsigned int tagmask, struct cxgbi_tag_format *);
+unsigned int cxgbi_tagmask_set(unsigned int ppmax);
+
+#endif	/*__CXGB4PPM_H__*/