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 = scatterwalk_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 /* count number of elements in scatterlist */
  59 static inline int __sg_count(struct scatterlist *sg_list, int nbytes,
  60                              bool *chained)
  61 {
  62         struct scatterlist *sg = sg_list;
  63         int sg_nents = 0;
  64
  65         while (nbytes > 0) {
  66                 sg_nents++;
  67                 nbytes -= sg->length;
  68                 if (!sg_is_last(sg) && (sg + 1)->length == 0)
  69                         *chained = true;
  70                 sg = scatterwalk_sg_next(sg);
  71         }
  72
  73         return sg_nents;
  74 }
  75
  76 /* derive number of elements in scatterlist, but return 0 for 1 */
  77 static inline int sg_count(struct scatterlist *sg_list, int nbytes,
  78                              bool *chained)
  79 {
  80         int sg_nents = __sg_count(sg_list, nbytes, chained);
  81
  82         if (likely(sg_nents == 1))
  83                 return 0;
  84
  85         return sg_nents;
  86 }
  87
  88 static int dma_map_sg_chained(struct device *dev, struct scatterlist *sg,
  89                               unsigned int nents, enum dma_data_direction dir,
  90                               bool chained)
  91 {
  92         if (unlikely(chained)) {
  93                 int i;
  94                 for (i = 0; i < nents; i++) {
  95                         dma_map_sg(dev, sg, 1, dir);
  96                         sg = scatterwalk_sg_next(sg);
  97                 }
  98         } else {
  99                 dma_map_sg(dev, sg, nents, dir);
 100         }
 101         return nents;
 102 }
 103
 104 static int dma_unmap_sg_chained(struct device *dev, struct scatterlist *sg,
 105                                 unsigned int nents, enum dma_data_direction dir,
 106                                 bool chained)
 107 {
 108         if (unlikely(chained)) {
 109                 int i;
 110                 for (i = 0; i < nents; i++) {
 111                         dma_unmap_sg(dev, sg, 1, dir);
 112                         sg = scatterwalk_sg_next(sg);
 113                 }
 114         } else {
 115                 dma_unmap_sg(dev, sg, nents, dir);
 116         }
 117         return nents;
 118 }
 119
 120 /* Map SG page in kernel virtual address space and copy */
 121 static inline void sg_map_copy(u8 *dest, struct scatterlist *sg,
 122                                int len, int offset)
 123 {
 124         u8 *mapped_addr;
 125
 126         /*
 127          * Page here can be user-space pinned using get_user_pages
 128          * Same must be kmapped before use and kunmapped subsequently
 129          */
 130         mapped_addr = kmap_atomic(sg_page(sg));
 131         memcpy(dest, mapped_addr + offset, len);
 132         kunmap_atomic(mapped_addr);
 133 }
 134
 135 /* Copy from len bytes of sg to dest, starting from beginning */
 136 static inline void sg_copy(u8 *dest, struct scatterlist *sg, unsigned int len)
 137 {
 138         struct scatterlist *current_sg = sg;
 139         int cpy_index = 0, next_cpy_index = current_sg->length;
 140
 141         while (next_cpy_index < len) {
 142                 sg_map_copy(dest + cpy_index, current_sg, current_sg->length,
 143                             current_sg->offset);
 144                 current_sg = scatterwalk_sg_next(current_sg);
 145                 cpy_index = next_cpy_index;
 146                 next_cpy_index += current_sg->length;
 147         }
 148         if (cpy_index < len)
 149                 sg_map_copy(dest + cpy_index, current_sg, len-cpy_index,
 150                             current_sg->offset);
 151 }
 152
 153 /* Copy sg data, from to_skip to end, to dest */
 154 static inline void sg_copy_part(u8 *dest, struct scatterlist *sg,
 155                                       int to_skip, unsigned int end)
 156 {
 157         struct scatterlist *current_sg = sg;
 158         int sg_index, cpy_index, offset;
 159
 160         sg_index = current_sg->length;
 161         while (sg_index <= to_skip) {
 162                 current_sg = scatterwalk_sg_next(current_sg);
 163                 sg_index += current_sg->length;
 164         }
 165         cpy_index = sg_index - to_skip;
 166         offset = current_sg->offset + current_sg->length - cpy_index;
 167         sg_map_copy(dest, current_sg, cpy_index, offset);
 168         if (end - sg_index) {
 169                 current_sg = scatterwalk_sg_next(current_sg);
 170                 sg_copy(dest + cpy_index, current_sg, end - sg_index);
 171         }
 172 }