1 /* 2 * Author(s)......: Holger Smolinski <Holger.Smolinski@de.ibm.com> 3 * Martin Schwidefsky <schwidefsky@de.ibm.com> 4 * Bugreports.to..: <Linux390@de.ibm.com> 5 * Copyright IBM Corp. 2000 6 * 7 * History of changes 8 * 07/24/00 new file 9 * 05/04/02 code restructuring. 10 */ 11 12 #ifndef _S390_IDALS_H 13 #define _S390_IDALS_H 14 15 #include <linux/errno.h> 16 #include <linux/err.h> 17 #include <linux/types.h> 18 #include <linux/slab.h> 19 #include <asm/cio.h> 20 #include <asm/uaccess.h> 21 22 #ifdef CONFIG_64BIT 23 #define IDA_SIZE_LOG 12 /* 11 for 2k , 12 for 4k */ 24 #else 25 #define IDA_SIZE_LOG 11 /* 11 for 2k , 12 for 4k */ 26 #endif 27 #define IDA_BLOCK_SIZE (1L<<IDA_SIZE_LOG) 28 29 /* 30 * Test if an address/length pair needs an idal list. 31 */ 32 static inline int 33 idal_is_needed(void *vaddr, unsigned int length) 34 { 35 #ifdef CONFIG_64BIT 36 return ((__pa(vaddr) + length - 1) >> 31) != 0; 37 #else 38 return 0; 39 #endif 40 } 41 42 43 /* 44 * Return the number of idal words needed for an address/length pair. 45 */ 46 static inline unsigned int idal_nr_words(void *vaddr, unsigned int length) 47 { 48 return ((__pa(vaddr) & (IDA_BLOCK_SIZE-1)) + length + 49 (IDA_BLOCK_SIZE-1)) >> IDA_SIZE_LOG; 50 } 51 52 /* 53 * Create the list of idal words for an address/length pair. 54 */ 55 static inline unsigned long *idal_create_words(unsigned long *idaws, 56 void *vaddr, unsigned int length) 57 { 58 unsigned long paddr; 59 unsigned int cidaw; 60 61 paddr = __pa(vaddr); 62 cidaw = ((paddr & (IDA_BLOCK_SIZE-1)) + length + 63 (IDA_BLOCK_SIZE-1)) >> IDA_SIZE_LOG; 64 *idaws++ = paddr; 65 paddr &= -IDA_BLOCK_SIZE; 66 while (--cidaw > 0) { 67 paddr += IDA_BLOCK_SIZE; 68 *idaws++ = paddr; 69 } 70 return idaws; 71 } 72 73 /* 74 * Sets the address of the data in CCW. 75 * If necessary it allocates an IDAL and sets the appropriate flags. 76 */ 77 static inline int 78 set_normalized_cda(struct ccw1 * ccw, void *vaddr) 79 { 80 #ifdef CONFIG_64BIT 81 unsigned int nridaws; 82 unsigned long *idal; 83 84 if (ccw->flags & CCW_FLAG_IDA) 85 return -EINVAL; 86 nridaws = idal_nr_words(vaddr, ccw->count); 87 if (nridaws > 0) { 88 idal = kmalloc(nridaws * sizeof(unsigned long), 89 GFP_ATOMIC | GFP_DMA ); 90 if (idal == NULL) 91 return -ENOMEM; 92 idal_create_words(idal, vaddr, ccw->count); 93 ccw->flags |= CCW_FLAG_IDA; 94 vaddr = idal; 95 } 96 #endif 97 ccw->cda = (__u32)(unsigned long) vaddr; 98 return 0; 99 } 100 101 /* 102 * Releases any allocated IDAL related to the CCW. 103 */ 104 static inline void 105 clear_normalized_cda(struct ccw1 * ccw) 106 { 107 #ifdef CONFIG_64BIT 108 if (ccw->flags & CCW_FLAG_IDA) { 109 kfree((void *)(unsigned long) ccw->cda); 110 ccw->flags &= ~CCW_FLAG_IDA; 111 } 112 #endif 113 ccw->cda = 0; 114 } 115 116 /* 117 * Idal buffer extension 118 */ 119 struct idal_buffer { 120 size_t size; 121 size_t page_order; 122 void *data[0]; 123 }; 124 125 /* 126 * Allocate an idal buffer 127 */ 128 static inline struct idal_buffer * 129 idal_buffer_alloc(size_t size, int page_order) 130 { 131 struct idal_buffer *ib; 132 int nr_chunks, nr_ptrs, i; 133 134 nr_ptrs = (size + IDA_BLOCK_SIZE - 1) >> IDA_SIZE_LOG; 135 nr_chunks = (4096 << page_order) >> IDA_SIZE_LOG; 136 ib = kmalloc(sizeof(struct idal_buffer) + nr_ptrs*sizeof(void *), 137 GFP_DMA | GFP_KERNEL); 138 if (ib == NULL) 139 return ERR_PTR(-ENOMEM); 140 ib->size = size; 141 ib->page_order = page_order; 142 for (i = 0; i < nr_ptrs; i++) { 143 if ((i & (nr_chunks - 1)) != 0) { 144 ib->data[i] = ib->data[i-1] + IDA_BLOCK_SIZE; 145 continue; 146 } 147 ib->data[i] = (void *) 148 __get_free_pages(GFP_KERNEL, page_order); 149 if (ib->data[i] != NULL) 150 continue; 151 // Not enough memory 152 while (i >= nr_chunks) { 153 i -= nr_chunks; 154 free_pages((unsigned long) ib->data[i], 155 ib->page_order); 156 } 157 kfree(ib); 158 return ERR_PTR(-ENOMEM); 159 } 160 return ib; 161 } 162 163 /* 164 * Free an idal buffer. 165 */ 166 static inline void 167 idal_buffer_free(struct idal_buffer *ib) 168 { 169 int nr_chunks, nr_ptrs, i; 170 171 nr_ptrs = (ib->size + IDA_BLOCK_SIZE - 1) >> IDA_SIZE_LOG; 172 nr_chunks = (4096 << ib->page_order) >> IDA_SIZE_LOG; 173 for (i = 0; i < nr_ptrs; i += nr_chunks) 174 free_pages((unsigned long) ib->data[i], ib->page_order); 175 kfree(ib); 176 } 177 178 /* 179 * Test if a idal list is really needed. 180 */ 181 static inline int 182 __idal_buffer_is_needed(struct idal_buffer *ib) 183 { 184 #ifdef CONFIG_64BIT 185 return ib->size > (4096ul << ib->page_order) || 186 idal_is_needed(ib->data[0], ib->size); 187 #else 188 return ib->size > (4096ul << ib->page_order); 189 #endif 190 } 191 192 /* 193 * Set channel data address to idal buffer. 194 */ 195 static inline void 196 idal_buffer_set_cda(struct idal_buffer *ib, struct ccw1 *ccw) 197 { 198 if (__idal_buffer_is_needed(ib)) { 199 // setup idals; 200 ccw->cda = (u32)(addr_t) ib->data; 201 ccw->flags |= CCW_FLAG_IDA; 202 } else 203 // we do not need idals - use direct addressing 204 ccw->cda = (u32)(addr_t) ib->data[0]; 205 ccw->count = ib->size; 206 } 207 208 /* 209 * Copy count bytes from an idal buffer to user memory 210 */ 211 static inline size_t 212 idal_buffer_to_user(struct idal_buffer *ib, void __user *to, size_t count) 213 { 214 size_t left; 215 int i; 216 217 BUG_ON(count > ib->size); 218 for (i = 0; count > IDA_BLOCK_SIZE; i++) { 219 left = copy_to_user(to, ib->data[i], IDA_BLOCK_SIZE); 220 if (left) 221 return left + count - IDA_BLOCK_SIZE; 222 to = (void __user *) to + IDA_BLOCK_SIZE; 223 count -= IDA_BLOCK_SIZE; 224 } 225 return copy_to_user(to, ib->data[i], count); 226 } 227 228 /* 229 * Copy count bytes from user memory to an idal buffer 230 */ 231 static inline size_t 232 idal_buffer_from_user(struct idal_buffer *ib, const void __user *from, size_t count) 233 { 234 size_t left; 235 int i; 236 237 BUG_ON(count > ib->size); 238 for (i = 0; count > IDA_BLOCK_SIZE; i++) { 239 left = copy_from_user(ib->data[i], from, IDA_BLOCK_SIZE); 240 if (left) 241 return left + count - IDA_BLOCK_SIZE; 242 from = (void __user *) from + IDA_BLOCK_SIZE; 243 count -= IDA_BLOCK_SIZE; 244 } 245 return copy_from_user(ib->data[i], from, count); 246 } 247 248 #endif 249