drivers/scsi/cxgb3i/cxgb3i_ddp.h

   1 /*
   2  * cxgb3i_ddp.h: Chelsio S3xx iSCSI DDP Manager.
   3  *
   4  * Copyright (c) 2008 Chelsio Communications, Inc.
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation.
   9  *
  10  * Written by: Karen Xie (kxie@chelsio.com)
  11  */
  12
  13 #ifndef __CXGB3I_ULP2_DDP_H__
  14 #define __CXGB3I_ULP2_DDP_H__
  15
  16 #include <linux/vmalloc.h>
  17
  18 /**
  19  * struct cxgb3i_tag_format - cxgb3i ulp tag format for an iscsi entity
  20  *
  21  * @sw_bits:    # of bits used by iscsi software layer
  22  * @rsvd_bits:  # of bits used by h/w
  23  * @rsvd_shift: h/w bits shift left
  24  * @rsvd_mask:  reserved bit mask
  25  */
  26 struct cxgb3i_tag_format {
  27         unsigned char sw_bits;
  28         unsigned char rsvd_bits;
  29         unsigned char rsvd_shift;
  30         unsigned char filler[1];
  31         u32 rsvd_mask;
  32 };
  33
  34 /**
  35  * struct cxgb3i_gather_list - cxgb3i direct data placement memory
  36  *
  37  * @tag:        ddp tag
  38  * @length:     total data buffer length
  39  * @offset:     initial offset to the 1st page
  40  * @nelem:      # of pages
  41  * @pages:      page pointers
  42  * @phys_addr:  physical address
  43  */
  44 struct cxgb3i_gather_list {
  45         u32 tag;
  46         unsigned int length;
  47         unsigned int offset;
  48         unsigned int nelem;
  49         struct page **pages;
  50         dma_addr_t phys_addr[0];
  51 };
  52
  53 /**
  54  * struct cxgb3i_ddp_info - cxgb3i direct data placement for pdu payload
  55  *
  56  * @list:       list head to link elements
  57  * @tdev:       pointer to t3cdev used by cxgb3 driver
  58  * @max_txsz:   max tx packet size for ddp
  59  * @max_rxsz:   max rx packet size for ddp
  60  * @llimit:     lower bound of the page pod memory
  61  * @ulimit:     upper bound of the page pod memory
  62  * @nppods:     # of page pod entries
  63  * @idx_last:   page pod entry last used
  64  * @idx_bits:   # of bits the pagepod index would take
  65  * @idx_mask:   pagepod index mask
  66  * @rsvd_tag_mask: tag mask
  67  * @map_lock:   lock to synchonize access to the page pod map
  68  * @gl_map:     ddp memory gather list
  69  * @gl_skb:     skb used to program the pagepod
  70  */
  71 struct cxgb3i_ddp_info {
  72         struct list_head list;
  73         struct t3cdev *tdev;
  74         struct pci_dev *pdev;
  75         unsigned int max_txsz;
  76         unsigned int max_rxsz;
  77         unsigned int llimit;
  78         unsigned int ulimit;
  79         unsigned int nppods;
  80         unsigned int idx_last;
  81         unsigned char idx_bits;
  82         unsigned char filler[3];
  83         u32 idx_mask;
  84         u32 rsvd_tag_mask;
  85         spinlock_t map_lock;
  86         struct cxgb3i_gather_list **gl_map;
  87         struct sk_buff **gl_skb;
  88 };
  89
  90 #define ISCSI_PDU_NONPAYLOAD_LEN        312 /* bhs(48) + ahs(256) + digest(8) */
  91 #define ULP2_MAX_PKT_SIZE       16224
  92 #define ULP2_MAX_PDU_PAYLOAD    (ULP2_MAX_PKT_SIZE - ISCSI_PDU_NONPAYLOAD_LEN)
  93 #define PPOD_PAGES_MAX          4
  94 #define PPOD_PAGES_SHIFT        2       /* 4 pages per pod */
  95
  96 /*
  97  * struct pagepod_hdr, pagepod - pagepod format
  98  */
  99 struct pagepod_hdr {
 100         u32 vld_tid;
 101         u32 pgsz_tag_clr;
 102         u32 maxoffset;
 103         u32 pgoffset;
 104         u64 rsvd;
 105 };
 106
 107 struct pagepod {
 108         struct pagepod_hdr hdr;
 109         u64 addr[PPOD_PAGES_MAX + 1];
 110 };
 111
 112 #define PPOD_SIZE               sizeof(struct pagepod)  /* 64 */
 113 #define PPOD_SIZE_SHIFT         6
 114
 115 #define PPOD_COLOR_SHIFT        0
 116 #define PPOD_COLOR_SIZE         6
 117 #define PPOD_COLOR_MASK         ((1 << PPOD_COLOR_SIZE) - 1)
 118
 119 #define PPOD_IDX_SHIFT          PPOD_COLOR_SIZE
 120 #define PPOD_IDX_MAX_SIZE       24
 121
 122 #define S_PPOD_TID    0
 123 #define M_PPOD_TID    0xFFFFFF
 124 #define V_PPOD_TID(x) ((x) << S_PPOD_TID)
 125
 126 #define S_PPOD_VALID    24
 127 #define V_PPOD_VALID(x) ((x) << S_PPOD_VALID)
 128 #define F_PPOD_VALID    V_PPOD_VALID(1U)
 129
 130 #define S_PPOD_COLOR    0
 131 #define M_PPOD_COLOR    0x3F
 132 #define V_PPOD_COLOR(x) ((x) << S_PPOD_COLOR)
 133
 134 #define S_PPOD_TAG    6
 135 #define M_PPOD_TAG    0xFFFFFF
 136 #define V_PPOD_TAG(x) ((x) << S_PPOD_TAG)
 137
 138 #define S_PPOD_PGSZ    30
 139 #define M_PPOD_PGSZ    0x3
 140 #define V_PPOD_PGSZ(x) ((x) << S_PPOD_PGSZ)
 141
 142 /*
 143  * large memory chunk allocation/release
 144  * use vmalloc() if kmalloc() fails
 145  */
 146 static inline void *cxgb3i_alloc_big_mem(unsigned int size,
 147                                          gfp_t gfp)
 148 {
 149         void *p = kmalloc(size, gfp);
 150         if (!p)
 151                 p = vmalloc(size);
 152         if (p)
 153                 memset(p, 0, size);
 154         return p;
 155 }
 156
 157 static inline void cxgb3i_free_big_mem(void *addr)
 158 {
 159         if (is_vmalloc_addr(addr))
 160                 vfree(addr);
 161         else
 162                 kfree(addr);
 163 }
 164
 165 /*
 166  * cxgb3i ddp tag are 32 bits, it consists of reserved bits used by h/w and
 167  * non-reserved bits that can be used by the iscsi s/w.
 168  * The reserved bits are identified by the rsvd_bits and rsvd_shift fields
 169  * in struct cxgb3i_tag_format.
 170  *
 171  * The upper most reserved bit can be used to check if a tag is ddp tag or not:
 172  *      if the bit is 0, the tag is a valid ddp tag
 173  */
 174
 175 /**
 176  * cxgb3i_is_ddp_tag - check if a given tag is a hw/ddp tag
 177  * @tformat: tag format information
 178  * @tag: tag to be checked
 179  *
 180  * return true if the tag is a ddp tag, false otherwise.
 181  */
 182 static inline int cxgb3i_is_ddp_tag(struct cxgb3i_tag_format *tformat, u32 tag)
 183 {
 184         return !(tag & (1 << (tformat->rsvd_bits + tformat->rsvd_shift - 1)));
 185 }
 186
 187 /**
 188  * cxgb3i_sw_tag_usable - check if s/w tag has enough bits left for hw bits
 189  * @tformat: tag format information
 190  * @sw_tag: s/w tag to be checked
 191  *
 192  * return true if the tag can be used for hw ddp tag, false otherwise.
 193  */
 194 static inline int cxgb3i_sw_tag_usable(struct cxgb3i_tag_format *tformat,
 195                                         u32 sw_tag)
 196 {
 197         sw_tag >>= (32 - tformat->rsvd_bits);
 198         return !sw_tag;
 199 }
 200
 201 /**
 202  * cxgb3i_set_non_ddp_tag - mark a given s/w tag as an invalid ddp tag
 203  * @tformat: tag format information
 204  * @sw_tag: s/w tag to be checked
 205  *
 206  * insert 1 at the upper most reserved bit to mark it as an invalid ddp tag.
 207  */
 208 static inline u32 cxgb3i_set_non_ddp_tag(struct cxgb3i_tag_format *tformat,
 209                                          u32 sw_tag)
 210 {
 211         unsigned char shift = tformat->rsvd_bits + tformat->rsvd_shift - 1;
 212         u32 mask = (1 << shift) - 1;
 213
 214         if (sw_tag && (sw_tag & ~mask)) {
 215                 u32 v1 = sw_tag & ((1 << shift) - 1);
 216                 u32 v2 = (sw_tag >> (shift - 1)) << shift;
 217
 218                 return v2 | v1 | 1 << shift;
 219         }
 220         return sw_tag | 1 << shift;
 221 }
 222
 223 /**
 224  * cxgb3i_ddp_tag_base - shift s/w tag bits so that reserved bits are not used
 225  * @tformat: tag format information
 226  * @sw_tag: s/w tag to be checked
 227  */
 228 static inline u32 cxgb3i_ddp_tag_base(struct cxgb3i_tag_format *tformat,
 229                                       u32 sw_tag)
 230 {
 231         u32 mask = (1 << tformat->rsvd_shift) - 1;
 232
 233         if (sw_tag && (sw_tag & ~mask)) {
 234                 u32 v1 = sw_tag & mask;
 235                 u32 v2 = sw_tag >> tformat->rsvd_shift;
 236
 237                 v2 <<= tformat->rsvd_shift + tformat->rsvd_bits;
 238                 return v2 | v1;
 239         }
 240         return sw_tag;
 241 }
 242
 243 /**
 244  * cxgb3i_tag_rsvd_bits - get the reserved bits used by the h/w
 245  * @tformat: tag format information
 246  * @tag: tag to be checked
 247  *
 248  * return the reserved bits in the tag
 249  */
 250 static inline u32 cxgb3i_tag_rsvd_bits(struct cxgb3i_tag_format *tformat,
 251                                        u32 tag)
 252 {
 253         if (cxgb3i_is_ddp_tag(tformat, tag))
 254                 return (tag >> tformat->rsvd_shift) & tformat->rsvd_mask;
 255         return 0;
 256 }
 257
 258 /**
 259  * cxgb3i_tag_nonrsvd_bits - get the non-reserved bits used by the s/w
 260  * @tformat: tag format information
 261  * @tag: tag to be checked
 262  *
 263  * return the non-reserved bits in the tag.
 264  */
 265 static inline u32 cxgb3i_tag_nonrsvd_bits(struct cxgb3i_tag_format *tformat,
 266                                           u32 tag)
 267 {
 268         unsigned char shift = tformat->rsvd_bits + tformat->rsvd_shift - 1;
 269         u32 v1, v2;
 270
 271         if (cxgb3i_is_ddp_tag(tformat, tag)) {
 272                 v1 = tag & ((1 << tformat->rsvd_shift) - 1);
 273                 v2 = (tag >> (shift + 1)) << tformat->rsvd_shift;
 274         } else {
 275                 u32 mask = (1 << shift) - 1;
 276
 277                 tag &= ~(1 << shift);
 278                 v1 = tag & mask;
 279                 v2 = (tag >> 1) & ~mask;
 280         }
 281         return v1 | v2;
 282 }
 283
 284 int cxgb3i_ddp_tag_reserve(struct t3cdev *, unsigned int tid,
 285                            struct cxgb3i_tag_format *, u32 *tag,
 286                            struct cxgb3i_gather_list *, gfp_t gfp);
 287 void cxgb3i_ddp_tag_release(struct t3cdev *, u32 tag);
 288
 289 struct cxgb3i_gather_list *cxgb3i_ddp_make_gl(unsigned int xferlen,
 290                                 struct scatterlist *sgl,
 291                                 unsigned int sgcnt,
 292                                 struct pci_dev *pdev,
 293                                 gfp_t gfp);
 294 void cxgb3i_ddp_release_gl(struct cxgb3i_gather_list *gl,
 295                                 struct pci_dev *pdev);
 296
 297 int cxgb3i_setup_conn_host_pagesize(struct t3cdev *, unsigned int tid,
 298                                     int reply);
 299 int cxgb3i_setup_conn_pagesize(struct t3cdev *, unsigned int tid, int reply,
 300                                unsigned long pgsz);
 301 int cxgb3i_setup_conn_digest(struct t3cdev *, unsigned int tid,
 302                                 int hcrc, int dcrc, int reply);
 303 int cxgb3i_ddp_find_page_index(unsigned long pgsz);
 304 int cxgb3i_adapter_ddp_info(struct t3cdev *, struct cxgb3i_tag_format *,
 305                             unsigned int *txsz, unsigned int *rxsz);
 306
 307 void cxgb3i_ddp_init(struct t3cdev *);
 308 void cxgb3i_ddp_cleanup(struct t3cdev *);
 309 #endif