include/asm-s390/idals.h

   1 /*
   2  * File...........: linux/include/asm-s390x/idals.h
   3  * Author(s)......: Holger Smolinski <Holger.Smolinski@de.ibm.com>
   4  *                  Martin Schwidefsky <schwidefsky@de.ibm.com>
   5  * Bugreports.to..: <Linux390@de.ibm.com>
   6  * (C) IBM Corporation, IBM Deutschland Entwicklung GmbH, 2000a
   7
   8  * History of changes
   9  * 07/24/00 new file
  10  * 05/04/02 code restructuring.
  11  */
  12
  13 #ifndef _S390_IDALS_H
  14 #define _S390_IDALS_H
  15
  16 #include <linux/errno.h>
  17 #include <linux/err.h>
  18 #include <linux/types.h>
  19 #include <linux/slab.h>
  20 #include <asm/cio.h>
  21 #include <asm/uaccess.h>
  22
  23 #ifdef __s390x__
  24 #define IDA_SIZE_LOG 12 /* 11 for 2k , 12 for 4k */
  25 #else
  26 #define IDA_SIZE_LOG 11 /* 11 for 2k , 12 for 4k */
  27 #endif
  28 #define IDA_BLOCK_SIZE (1L<<IDA_SIZE_LOG)
  29
  30 /*
  31  * Test if an address/length pair needs an idal list.
  32  */
  33 static inline int
  34 idal_is_needed(void *vaddr, unsigned int length)
  35 {
  36 #ifdef __s390x__
  37         return ((__pa(vaddr) + length - 1) >> 31) != 0;
  38 #else
  39         return 0;
  40 #endif
  41 }
  42
  43
  44 /*
  45  * Return the number of idal words needed for an address/length pair.
  46  */
  47 static inline unsigned int
  48 idal_nr_words(void *vaddr, unsigned int length)
  49 {
  50 #ifdef __s390x__
  51         if (idal_is_needed(vaddr, length))
  52                 return ((__pa(vaddr) & (IDA_BLOCK_SIZE-1)) + length +
  53                         (IDA_BLOCK_SIZE-1)) >> IDA_SIZE_LOG;
  54 #endif
  55         return 0;
  56 }
  57
  58 /*
  59  * Create the list of idal words for an address/length pair.
  60  */
  61 static inline unsigned long *
  62 idal_create_words(unsigned long *idaws, void *vaddr, unsigned int length)
  63 {
  64 #ifdef __s390x__
  65         unsigned long paddr;
  66         unsigned int cidaw;
  67
  68         paddr = __pa(vaddr);
  69         cidaw = ((paddr & (IDA_BLOCK_SIZE-1)) + length +
  70                  (IDA_BLOCK_SIZE-1)) >> IDA_SIZE_LOG;
  71         *idaws++ = paddr;
  72         paddr &= -IDA_BLOCK_SIZE;
  73         while (--cidaw > 0) {
  74                 paddr += IDA_BLOCK_SIZE;
  75                 *idaws++ = paddr;
  76         }
  77 #endif
  78         return idaws;
  79 }
  80
  81 /*
  82  * Sets the address of the data in CCW.
  83  * If necessary it allocates an IDAL and sets the appropriate flags.
  84  */
  85 static inline int
  86 set_normalized_cda(struct ccw1 * ccw, void *vaddr)
  87 {
  88 #ifdef __s390x__
  89         unsigned int nridaws;
  90         unsigned long *idal;
  91
  92         if (ccw->flags & CCW_FLAG_IDA)
  93                 return -EINVAL;
  94         nridaws = idal_nr_words(vaddr, ccw->count);
  95         if (nridaws > 0) {
  96                 idal = kmalloc(nridaws * sizeof(unsigned long),
  97                                GFP_ATOMIC | GFP_DMA );
  98                 if (idal == NULL)
  99                         return -ENOMEM;
 100                 idal_create_words(idal, vaddr, ccw->count);
 101                 ccw->flags |= CCW_FLAG_IDA;
 102                 vaddr = idal;
 103         }
 104 #endif
 105         ccw->cda = (__u32)(unsigned long) vaddr;
 106         return 0;
 107 }
 108
 109 /*
 110  * Releases any allocated IDAL related to the CCW.
 111  */
 112 static inline void
 113 clear_normalized_cda(struct ccw1 * ccw)
 114 {
 115 #ifdef __s390x__
 116         if (ccw->flags & CCW_FLAG_IDA) {
 117                 kfree((void *)(unsigned long) ccw->cda);
 118                 ccw->flags &= ~CCW_FLAG_IDA;
 119         }
 120 #endif
 121         ccw->cda = 0;
 122 }
 123
 124 /*
 125  * Idal buffer extension
 126  */
 127 struct idal_buffer {
 128         size_t size;
 129         size_t page_order;
 130         void *data[0];
 131 };
 132
 133 /*
 134  * Allocate an idal buffer
 135  */
 136 static inline struct idal_buffer *
 137 idal_buffer_alloc(size_t size, int page_order)
 138 {
 139         struct idal_buffer *ib;
 140         int nr_chunks, nr_ptrs, i;
 141
 142         nr_ptrs = (size + IDA_BLOCK_SIZE - 1) >> IDA_SIZE_LOG;
 143         nr_chunks = (4096 << page_order) >> IDA_SIZE_LOG;
 144         ib = kmalloc(sizeof(struct idal_buffer) + nr_ptrs*sizeof(void *),
 145                      GFP_DMA | GFP_KERNEL);
 146         if (ib == NULL)
 147                 return ERR_PTR(-ENOMEM);
 148         ib->size = size;
 149         ib->page_order = page_order;
 150         for (i = 0; i < nr_ptrs; i++) {
 151                 if ((i & (nr_chunks - 1)) != 0) {
 152                         ib->data[i] = ib->data[i-1] + IDA_BLOCK_SIZE;
 153                         continue;
 154                 }
 155                 ib->data[i] = (void *)
 156                         __get_free_pages(GFP_KERNEL, page_order);
 157                 if (ib->data[i] != NULL)
 158                         continue;
 159                 // Not enough memory
 160                 while (i >= nr_chunks) {
 161                         i -= nr_chunks;
 162                         free_pages((unsigned long) ib->data[i],
 163                                    ib->page_order);
 164                 }
 165                 kfree(ib);
 166                 return ERR_PTR(-ENOMEM);
 167         }
 168         return ib;
 169 }
 170
 171 /*
 172  * Free an idal buffer.
 173  */
 174 static inline void
 175 idal_buffer_free(struct idal_buffer *ib)
 176 {
 177         int nr_chunks, nr_ptrs, i;
 178
 179         nr_ptrs = (ib->size + IDA_BLOCK_SIZE - 1) >> IDA_SIZE_LOG;
 180         nr_chunks = (4096 << ib->page_order) >> IDA_SIZE_LOG;
 181         for (i = 0; i < nr_ptrs; i += nr_chunks)
 182                 free_pages((unsigned long) ib->data[i], ib->page_order);
 183         kfree(ib);
 184 }
 185
 186 /*
 187  * Test if a idal list is really needed.
 188  */
 189 static inline int
 190 __idal_buffer_is_needed(struct idal_buffer *ib)
 191 {
 192 #ifdef __s390x__
 193         return ib->size > (4096ul << ib->page_order) ||
 194                 idal_is_needed(ib->data[0], ib->size);
 195 #else
 196         return ib->size > (4096ul << ib->page_order);
 197 #endif
 198 }
 199
 200 /*
 201  * Set channel data address to idal buffer.
 202  */
 203 static inline void
 204 idal_buffer_set_cda(struct idal_buffer *ib, struct ccw1 *ccw)
 205 {
 206         if (__idal_buffer_is_needed(ib)) {
 207                 // setup idals;
 208                 ccw->cda = (u32)(addr_t) ib->data;
 209                 ccw->flags |= CCW_FLAG_IDA;
 210         } else
 211                 // we do not need idals - use direct addressing
 212                 ccw->cda = (u32)(addr_t) ib->data[0];
 213         ccw->count = ib->size;
 214 }
 215
 216 /*
 217  * Copy count bytes from an idal buffer to user memory
 218  */
 219 static inline size_t
 220 idal_buffer_to_user(struct idal_buffer *ib, void __user *to, size_t count)
 221 {
 222         size_t left;
 223         int i;
 224
 225         BUG_ON(count > ib->size);
 226         for (i = 0; count > IDA_BLOCK_SIZE; i++) {
 227                 left = copy_to_user(to, ib->data[i], IDA_BLOCK_SIZE);
 228                 if (left)
 229                         return left + count - IDA_BLOCK_SIZE;
 230                 to = (void __user *) to + IDA_BLOCK_SIZE;
 231                 count -= IDA_BLOCK_SIZE;
 232         }
 233         return copy_to_user(to, ib->data[i], count);
 234 }
 235
 236 /*
 237  * Copy count bytes from user memory to an idal buffer
 238  */
 239 static inline size_t
 240 idal_buffer_from_user(struct idal_buffer *ib, const void __user *from, size_t count)
 241 {
 242         size_t left;
 243         int i;
 244
 245         BUG_ON(count > ib->size);
 246         for (i = 0; count > IDA_BLOCK_SIZE; i++) {
 247                 left = copy_from_user(ib->data[i], from, IDA_BLOCK_SIZE);
 248                 if (left)
 249                         return left + count - IDA_BLOCK_SIZE;
 250                 from = (void __user *) from + IDA_BLOCK_SIZE;
 251                 count -= IDA_BLOCK_SIZE;
 252         }
 253         return copy_from_user(ib->data[i], from, count);
 254 }
 255
 256 #endif