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