1 /* SPDX-License-Identifier: GPL-2.0 */
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
10 * 05/04/02 code restructuring.
16 #include <linux/errno.h>
17 #include <linux/err.h>
18 #include <linux/types.h>
19 #include <linux/slab.h>
21 #include <linux/uaccess.h>
23 #define IDA_SIZE_LOG 12 /* 11 for 2k , 12 for 4k */
24 #define IDA_BLOCK_SIZE (1L<<IDA_SIZE_LOG)
27 * Test if an address/length pair needs an idal list.
30 idal_is_needed(void *vaddr, unsigned int length)
32 return ((__pa(vaddr) + length - 1) >> 31) != 0;
37 * Return the number of idal words needed for an address/length pair.
39 static inline unsigned int idal_nr_words(void *vaddr, unsigned int length)
41 return ((__pa(vaddr) & (IDA_BLOCK_SIZE-1)) + length +
42 (IDA_BLOCK_SIZE-1)) >> IDA_SIZE_LOG;
46 * Create the list of idal words for an address/length pair.
48 static inline unsigned long *idal_create_words(unsigned long *idaws,
49 void *vaddr, unsigned int length)
55 cidaw = ((paddr & (IDA_BLOCK_SIZE-1)) + length +
56 (IDA_BLOCK_SIZE-1)) >> IDA_SIZE_LOG;
58 paddr &= -IDA_BLOCK_SIZE;
60 paddr += IDA_BLOCK_SIZE;
67 * Sets the address of the data in CCW.
68 * If necessary it allocates an IDAL and sets the appropriate flags.
71 set_normalized_cda(struct ccw1 * ccw, void *vaddr)
76 if (ccw->flags & CCW_FLAG_IDA)
78 nridaws = idal_nr_words(vaddr, ccw->count);
80 idal = kmalloc(nridaws * sizeof(unsigned long),
81 GFP_ATOMIC | GFP_DMA );
84 idal_create_words(idal, vaddr, ccw->count);
85 ccw->flags |= CCW_FLAG_IDA;
88 ccw->cda = (__u32)(unsigned long) vaddr;
93 * Releases any allocated IDAL related to the CCW.
96 clear_normalized_cda(struct ccw1 * ccw)
98 if (ccw->flags & CCW_FLAG_IDA) {
99 kfree((void *)(unsigned long) ccw->cda);
100 ccw->flags &= ~CCW_FLAG_IDA;
106 * Idal buffer extension
115 * Allocate an idal buffer
117 static inline struct idal_buffer *
118 idal_buffer_alloc(size_t size, int page_order)
120 struct idal_buffer *ib;
121 int nr_chunks, nr_ptrs, i;
123 nr_ptrs = (size + IDA_BLOCK_SIZE - 1) >> IDA_SIZE_LOG;
124 nr_chunks = (4096 << page_order) >> IDA_SIZE_LOG;
125 ib = kmalloc(sizeof(struct idal_buffer) + nr_ptrs*sizeof(void *),
126 GFP_DMA | GFP_KERNEL);
128 return ERR_PTR(-ENOMEM);
130 ib->page_order = page_order;
131 for (i = 0; i < nr_ptrs; i++) {
132 if ((i & (nr_chunks - 1)) != 0) {
133 ib->data[i] = ib->data[i-1] + IDA_BLOCK_SIZE;
136 ib->data[i] = (void *)
137 __get_free_pages(GFP_KERNEL, page_order);
138 if (ib->data[i] != NULL)
141 while (i >= nr_chunks) {
143 free_pages((unsigned long) ib->data[i],
147 return ERR_PTR(-ENOMEM);
153 * Free an idal buffer.
156 idal_buffer_free(struct idal_buffer *ib)
158 int nr_chunks, nr_ptrs, i;
160 nr_ptrs = (ib->size + IDA_BLOCK_SIZE - 1) >> IDA_SIZE_LOG;
161 nr_chunks = (4096 << ib->page_order) >> IDA_SIZE_LOG;
162 for (i = 0; i < nr_ptrs; i += nr_chunks)
163 free_pages((unsigned long) ib->data[i], ib->page_order);
168 * Test if a idal list is really needed.
171 __idal_buffer_is_needed(struct idal_buffer *ib)
173 return ib->size > (4096ul << ib->page_order) ||
174 idal_is_needed(ib->data[0], ib->size);
178 * Set channel data address to idal buffer.
181 idal_buffer_set_cda(struct idal_buffer *ib, struct ccw1 *ccw)
183 if (__idal_buffer_is_needed(ib)) {
185 ccw->cda = (u32)(addr_t) ib->data;
186 ccw->flags |= CCW_FLAG_IDA;
188 // we do not need idals - use direct addressing
189 ccw->cda = (u32)(addr_t) ib->data[0];
190 ccw->count = ib->size;
194 * Copy count bytes from an idal buffer to user memory
197 idal_buffer_to_user(struct idal_buffer *ib, void __user *to, size_t count)
202 BUG_ON(count > ib->size);
203 for (i = 0; count > IDA_BLOCK_SIZE; i++) {
204 left = copy_to_user(to, ib->data[i], IDA_BLOCK_SIZE);
206 return left + count - IDA_BLOCK_SIZE;
207 to = (void __user *) to + IDA_BLOCK_SIZE;
208 count -= IDA_BLOCK_SIZE;
210 return copy_to_user(to, ib->data[i], count);
214 * Copy count bytes from user memory to an idal buffer
217 idal_buffer_from_user(struct idal_buffer *ib, const void __user *from, size_t count)
222 BUG_ON(count > ib->size);
223 for (i = 0; count > IDA_BLOCK_SIZE; i++) {
224 left = copy_from_user(ib->data[i], from, IDA_BLOCK_SIZE);
226 return left + count - IDA_BLOCK_SIZE;
227 from = (void __user *) from + IDA_BLOCK_SIZE;
228 count -= IDA_BLOCK_SIZE;
230 return copy_from_user(ib->data[i], from, count);