1 /* SPDX-License-Identifier: GPL-2.0 */ 2 /* 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 * Copyright IBM Corp. 2000 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 <linux/uaccess.h> 22 23 #define IDA_SIZE_LOG 12 /* 11 for 2k , 12 for 4k */ 24 #define IDA_BLOCK_SIZE (1L<<IDA_SIZE_LOG) 25 26 #define IDA_2K_SIZE_LOG 11 27 #define IDA_2K_BLOCK_SIZE (1L << IDA_2K_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 return ((__pa(vaddr) + length - 1) >> 31) != 0; 36 } 37 38 39 /* 40 * Return the number of idal words needed for an address/length pair. 41 */ 42 static inline unsigned int idal_nr_words(void *vaddr, unsigned int length) 43 { 44 return ((__pa(vaddr) & (IDA_BLOCK_SIZE-1)) + length + 45 (IDA_BLOCK_SIZE-1)) >> IDA_SIZE_LOG; 46 } 47 48 /* 49 * Return the number of 2K IDA words needed for an address/length pair. 50 */ 51 static inline unsigned int idal_2k_nr_words(void *vaddr, unsigned int length) 52 { 53 return ((__pa(vaddr) & (IDA_2K_BLOCK_SIZE - 1)) + length + 54 (IDA_2K_BLOCK_SIZE - 1)) >> IDA_2K_SIZE_LOG; 55 } 56 57 /* 58 * Create the list of idal words for an address/length pair. 59 */ 60 static inline unsigned long *idal_create_words(unsigned long *idaws, 61 void *vaddr, unsigned int length) 62 { 63 unsigned long paddr; 64 unsigned int cidaw; 65 66 paddr = __pa(vaddr); 67 cidaw = ((paddr & (IDA_BLOCK_SIZE-1)) + length + 68 (IDA_BLOCK_SIZE-1)) >> IDA_SIZE_LOG; 69 *idaws++ = paddr; 70 paddr &= -IDA_BLOCK_SIZE; 71 while (--cidaw > 0) { 72 paddr += IDA_BLOCK_SIZE; 73 *idaws++ = paddr; 74 } 75 return idaws; 76 } 77 78 /* 79 * Sets the address of the data in CCW. 80 * If necessary it allocates an IDAL and sets the appropriate flags. 81 */ 82 static inline int 83 set_normalized_cda(struct ccw1 * ccw, void *vaddr) 84 { 85 unsigned int nridaws; 86 unsigned long *idal; 87 88 if (ccw->flags & CCW_FLAG_IDA) 89 return -EINVAL; 90 nridaws = idal_nr_words(vaddr, ccw->count); 91 if (nridaws > 0) { 92 idal = kmalloc(nridaws * sizeof(unsigned long), 93 GFP_ATOMIC | GFP_DMA ); 94 if (idal == NULL) 95 return -ENOMEM; 96 idal_create_words(idal, vaddr, ccw->count); 97 ccw->flags |= CCW_FLAG_IDA; 98 vaddr = idal; 99 } 100 ccw->cda = (__u32)(unsigned long) vaddr; 101 return 0; 102 } 103 104 /* 105 * Releases any allocated IDAL related to the CCW. 106 */ 107 static inline void 108 clear_normalized_cda(struct ccw1 * ccw) 109 { 110 if (ccw->flags & CCW_FLAG_IDA) { 111 kfree((void *)(unsigned long) ccw->cda); 112 ccw->flags &= ~CCW_FLAG_IDA; 113 } 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[]; 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(struct_size(ib, data, nr_ptrs), 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 return ib->size > (4096ul << ib->page_order) || 185 idal_is_needed(ib->data[0], ib->size); 186 } 187 188 /* 189 * Set channel data address to idal buffer. 190 */ 191 static inline void 192 idal_buffer_set_cda(struct idal_buffer *ib, struct ccw1 *ccw) 193 { 194 if (__idal_buffer_is_needed(ib)) { 195 // setup idals; 196 ccw->cda = (u32)(addr_t) ib->data; 197 ccw->flags |= CCW_FLAG_IDA; 198 } else 199 // we do not need idals - use direct addressing 200 ccw->cda = (u32)(addr_t) ib->data[0]; 201 ccw->count = ib->size; 202 } 203 204 /* 205 * Copy count bytes from an idal buffer to user memory 206 */ 207 static inline size_t 208 idal_buffer_to_user(struct idal_buffer *ib, void __user *to, size_t count) 209 { 210 size_t left; 211 int i; 212 213 BUG_ON(count > ib->size); 214 for (i = 0; count > IDA_BLOCK_SIZE; i++) { 215 left = copy_to_user(to, ib->data[i], IDA_BLOCK_SIZE); 216 if (left) 217 return left + count - IDA_BLOCK_SIZE; 218 to = (void __user *) to + IDA_BLOCK_SIZE; 219 count -= IDA_BLOCK_SIZE; 220 } 221 return copy_to_user(to, ib->data[i], count); 222 } 223 224 /* 225 * Copy count bytes from user memory to an idal buffer 226 */ 227 static inline size_t 228 idal_buffer_from_user(struct idal_buffer *ib, const void __user *from, size_t count) 229 { 230 size_t left; 231 int i; 232 233 BUG_ON(count > ib->size); 234 for (i = 0; count > IDA_BLOCK_SIZE; i++) { 235 left = copy_from_user(ib->data[i], from, IDA_BLOCK_SIZE); 236 if (left) 237 return left + count - IDA_BLOCK_SIZE; 238 from = (void __user *) from + IDA_BLOCK_SIZE; 239 count -= IDA_BLOCK_SIZE; 240 } 241 return copy_from_user(ib->data[i], from, count); 242 } 243 244 #endif 245