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