drivers/crypto/caam/sg_sw_sec4.h

   1 /*
   2  * CAAM/SEC 4.x functions for using scatterlists in caam driver
   3  *
   4  * Copyright 2008-2011 Freescale Semiconductor, Inc.
   5  *
   6  */
   7
   8 struct sec4_sg_entry;
   9
  10 /*
  11  * convert single dma address to h/w link table format
  12  */
  13 static inline void dma_to_sec4_sg_one(struct sec4_sg_entry *sec4_sg_ptr,
  14                                       dma_addr_t dma, u32 len, u32 offset)
  15 {
  16         sec4_sg_ptr->ptr = dma;
  17         sec4_sg_ptr->len = len;
  18         sec4_sg_ptr->reserved = 0;
  19         sec4_sg_ptr->buf_pool_id = 0;
  20         sec4_sg_ptr->offset = offset;
  21 #ifdef DEBUG
  22         print_hex_dump(KERN_ERR, "sec4_sg_ptr@: ",
  23                        DUMP_PREFIX_ADDRESS, 16, 4, sec4_sg_ptr,
  24                        sizeof(struct sec4_sg_entry), 1);
  25 #endif
  26 }
  27
  28 /*
  29  * convert scatterlist to h/w link table format
  30  * but does not have final bit; instead, returns last entry
  31  */
  32 static inline struct sec4_sg_entry *
  33 sg_to_sec4_sg(struct scatterlist *sg, int sg_count,
  34               struct sec4_sg_entry *sec4_sg_ptr, u32 offset)
  35 {
  36         while (sg_count) {
  37                 dma_to_sec4_sg_one(sec4_sg_ptr, sg_dma_address(sg),
  38                                    sg_dma_len(sg), offset);
  39                 sec4_sg_ptr++;
  40                 sg = sg_next(sg);
  41                 sg_count--;
  42         }
  43         return sec4_sg_ptr - 1;
  44 }
  45
  46 /*
  47  * convert scatterlist to h/w link table format
  48  * scatterlist must have been previously dma mapped
  49  */
  50 static inline void sg_to_sec4_sg_last(struct scatterlist *sg, int sg_count,
  51                                       struct sec4_sg_entry *sec4_sg_ptr,
  52                                       u32 offset)
  53 {
  54         sec4_sg_ptr = sg_to_sec4_sg(sg, sg_count, sec4_sg_ptr, offset);
  55         sec4_sg_ptr->len |= SEC4_SG_LEN_FIN;
  56 }
  57
  58 static inline struct sec4_sg_entry *sg_to_sec4_sg_len(
  59         struct scatterlist *sg, unsigned int total,
  60         struct sec4_sg_entry *sec4_sg_ptr)
  61 {
  62         do {
  63                 unsigned int len = min(sg_dma_len(sg), total);
  64
  65                 dma_to_sec4_sg_one(sec4_sg_ptr, sg_dma_address(sg), len, 0);
  66                 sec4_sg_ptr++;
  67                 sg = sg_next(sg);
  68                 total -= len;
  69         } while (total);
  70         return sec4_sg_ptr - 1;
  71 }
  72
  73 /* count number of elements in scatterlist */
  74 static inline int __sg_count(struct scatterlist *sg_list, int nbytes,
  75                              bool *chained)
  76 {
  77         struct scatterlist *sg = sg_list;
  78         int sg_nents = 0;
  79
  80         while (nbytes > 0) {
  81                 sg_nents++;
  82                 nbytes -= sg->length;
  83                 if (!sg_is_last(sg) && (sg + 1)->length == 0)
  84                         *chained = true;
  85                 sg = sg_next(sg);
  86         }
  87
  88         return sg_nents;
  89 }
  90
  91 /* derive number of elements in scatterlist, but return 0 for 1 */
  92 static inline int sg_count(struct scatterlist *sg_list, int nbytes,
  93                              bool *chained)
  94 {
  95         int sg_nents = __sg_count(sg_list, nbytes, chained);
  96
  97         if (likely(sg_nents == 1))
  98                 return 0;
  99
 100         return sg_nents;
 101 }
 102
 103 static inline void dma_unmap_sg_chained(
 104         struct device *dev, struct scatterlist *sg, unsigned int nents,
 105         enum dma_data_direction dir, bool chained)
 106 {
 107         if (unlikely(chained)) {
 108                 int i;
 109                 for (i = 0; i < nents; i++) {
 110                         dma_unmap_sg(dev, sg, 1, dir);
 111                         sg = sg_next(sg);
 112                 }
 113         } else if (nents) {
 114                 dma_unmap_sg(dev, sg, nents, dir);
 115         }
 116 }
 117
 118 static inline int dma_map_sg_chained(
 119         struct device *dev, struct scatterlist *sg, unsigned int nents,
 120         enum dma_data_direction dir, bool chained)
 121 {
 122         struct scatterlist *first = sg;
 123
 124         if (unlikely(chained)) {
 125                 int i;
 126                 for (i = 0; i < nents; i++) {
 127                         if (!dma_map_sg(dev, sg, 1, dir)) {
 128                                 dma_unmap_sg_chained(dev, first, i, dir,
 129                                                      chained);
 130                                 nents = 0;
 131                                 break;
 132                         }
 133
 134                         sg = sg_next(sg);
 135                 }
 136         } else
 137                 nents = dma_map_sg(dev, sg, nents, dir);
 138
 139         return nents;
 140 }