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 idal_nr_words(void *vaddr, unsigned int length) 48 { 49 return ((__pa(vaddr) & (IDA_BLOCK_SIZE-1)) + length + 50 (IDA_BLOCK_SIZE-1)) >> IDA_SIZE_LOG; 51 } 52 53 /* 54 * Create the list of idal words for an address/length pair. 55 */ 56 static inline unsigned long *idal_create_words(unsigned long *idaws, 57 void *vaddr, unsigned int length) 58 { 59 unsigned long paddr; 60 unsigned int cidaw; 61 62 paddr = __pa(vaddr); 63 cidaw = ((paddr & (IDA_BLOCK_SIZE-1)) + length + 64 (IDA_BLOCK_SIZE-1)) >> IDA_SIZE_LOG; 65 *idaws++ = paddr; 66 paddr &= -IDA_BLOCK_SIZE; 67 while (--cidaw > 0) { 68 paddr += IDA_BLOCK_SIZE; 69 *idaws++ = paddr; 70 } 71 return idaws; 72 } 73 74 /* 75 * Sets the address of the data in CCW. 76 * If necessary it allocates an IDAL and sets the appropriate flags. 77 */ 78 static inline int 79 set_normalized_cda(struct ccw1 * ccw, void *vaddr) 80 { 81 #ifdef __s390x__ 82 unsigned int nridaws; 83 unsigned long *idal; 84 85 if (ccw->flags & CCW_FLAG_IDA) 86 return -EINVAL; 87 nridaws = idal_nr_words(vaddr, ccw->count); 88 if (nridaws > 0) { 89 idal = kmalloc(nridaws * sizeof(unsigned long), 90 GFP_ATOMIC | GFP_DMA ); 91 if (idal == NULL) 92 return -ENOMEM; 93 idal_create_words(idal, vaddr, ccw->count); 94 ccw->flags |= CCW_FLAG_IDA; 95 vaddr = idal; 96 } 97 #endif 98 ccw->cda = (__u32)(unsigned long) vaddr; 99 return 0; 100 } 101 102 /* 103 * Releases any allocated IDAL related to the CCW. 104 */ 105 static inline void 106 clear_normalized_cda(struct ccw1 * ccw) 107 { 108 #ifdef __s390x__ 109 if (ccw->flags & CCW_FLAG_IDA) { 110 kfree((void *)(unsigned long) ccw->cda); 111 ccw->flags &= ~CCW_FLAG_IDA; 112 } 113 #endif 114 ccw->cda = 0; 115 } 116 117 /* 118 * Idal buffer extension 119 */ 120 struct idal_buffer { 121 size_t size; 122 size_t page_order; 123 void *data[0]; 124 }; 125 126 /* 127 * Allocate an idal buffer 128 */ 129 static inline struct idal_buffer * 130 idal_buffer_alloc(size_t size, int page_order) 131 { 132 struct idal_buffer *ib; 133 int nr_chunks, nr_ptrs, i; 134 135 nr_ptrs = (size + IDA_BLOCK_SIZE - 1) >> IDA_SIZE_LOG; 136 nr_chunks = (4096 << page_order) >> IDA_SIZE_LOG; 137 ib = kmalloc(sizeof(struct idal_buffer) + nr_ptrs*sizeof(void *), 138 GFP_DMA | GFP_KERNEL); 139 if (ib == NULL) 140 return ERR_PTR(-ENOMEM); 141 ib->size = size; 142 ib->page_order = page_order; 143 for (i = 0; i < nr_ptrs; i++) { 144 if ((i & (nr_chunks - 1)) != 0) { 145 ib->data[i] = ib->data[i-1] + IDA_BLOCK_SIZE; 146 continue; 147 } 148 ib->data[i] = (void *) 149 __get_free_pages(GFP_KERNEL, page_order); 150 if (ib->data[i] != NULL) 151 continue; 152 // Not enough memory 153 while (i >= nr_chunks) { 154 i -= nr_chunks; 155 free_pages((unsigned long) ib->data[i], 156 ib->page_order); 157 } 158 kfree(ib); 159 return ERR_PTR(-ENOMEM); 160 } 161 return ib; 162 } 163 164 /* 165 * Free an idal buffer. 166 */ 167 static inline void 168 idal_buffer_free(struct idal_buffer *ib) 169 { 170 int nr_chunks, nr_ptrs, i; 171 172 nr_ptrs = (ib->size + IDA_BLOCK_SIZE - 1) >> IDA_SIZE_LOG; 173 nr_chunks = (4096 << ib->page_order) >> IDA_SIZE_LOG; 174 for (i = 0; i < nr_ptrs; i += nr_chunks) 175 free_pages((unsigned long) ib->data[i], ib->page_order); 176 kfree(ib); 177 } 178 179 /* 180 * Test if a idal list is really needed. 181 */ 182 static inline int 183 __idal_buffer_is_needed(struct idal_buffer *ib) 184 { 185 #ifdef __s390x__ 186 return ib->size > (4096ul << ib->page_order) || 187 idal_is_needed(ib->data[0], ib->size); 188 #else 189 return ib->size > (4096ul << ib->page_order); 190 #endif 191 } 192 193 /* 194 * Set channel data address to idal buffer. 195 */ 196 static inline void 197 idal_buffer_set_cda(struct idal_buffer *ib, struct ccw1 *ccw) 198 { 199 if (__idal_buffer_is_needed(ib)) { 200 // setup idals; 201 ccw->cda = (u32)(addr_t) ib->data; 202 ccw->flags |= CCW_FLAG_IDA; 203 } else 204 // we do not need idals - use direct addressing 205 ccw->cda = (u32)(addr_t) ib->data[0]; 206 ccw->count = ib->size; 207 } 208 209 /* 210 * Copy count bytes from an idal buffer to user memory 211 */ 212 static inline size_t 213 idal_buffer_to_user(struct idal_buffer *ib, void __user *to, size_t count) 214 { 215 size_t left; 216 int i; 217 218 BUG_ON(count > ib->size); 219 for (i = 0; count > IDA_BLOCK_SIZE; i++) { 220 left = copy_to_user(to, ib->data[i], IDA_BLOCK_SIZE); 221 if (left) 222 return left + count - IDA_BLOCK_SIZE; 223 to = (void __user *) to + IDA_BLOCK_SIZE; 224 count -= IDA_BLOCK_SIZE; 225 } 226 return copy_to_user(to, ib->data[i], count); 227 } 228 229 /* 230 * Copy count bytes from user memory to an idal buffer 231 */ 232 static inline size_t 233 idal_buffer_from_user(struct idal_buffer *ib, const void __user *from, size_t count) 234 { 235 size_t left; 236 int i; 237 238 BUG_ON(count > ib->size); 239 for (i = 0; count > IDA_BLOCK_SIZE; i++) { 240 left = copy_from_user(ib->data[i], from, IDA_BLOCK_SIZE); 241 if (left) 242 return left + count - IDA_BLOCK_SIZE; 243 from = (void __user *) from + IDA_BLOCK_SIZE; 244 count -= IDA_BLOCK_SIZE; 245 } 246 return copy_from_user(ib->data[i], from, count); 247 } 248 249 #endif 250