thp: avoid dumping huge zero page
[linux-2.6/libata-dev.git] / drivers / message / i2o / memory.c
blob292b41e49fbd57c5881c03cf7daa889a72404948
1 /*
2 * Functions to handle I2O memory
4 * Pulled from the inlines in i2o headers and uninlined
7 * This program is free software; you can redistribute it and/or modify it
8 * under the terms of the GNU General Public License as published by the
9 * Free Software Foundation; either version 2 of the License, or (at your
10 * option) any later version.
13 #include <linux/module.h>
14 #include <linux/i2o.h>
15 #include <linux/delay.h>
16 #include <linux/string.h>
17 #include <linux/slab.h>
18 #include "core.h"
20 /* Protects our 32/64bit mask switching */
21 static DEFINE_MUTEX(mem_lock);
23 /**
24 * i2o_sg_tablesize - Calculate the maximum number of elements in a SGL
25 * @c: I2O controller for which the calculation should be done
26 * @body_size: maximum body size used for message in 32-bit words.
28 * Return the maximum number of SG elements in a SG list.
30 u16 i2o_sg_tablesize(struct i2o_controller *c, u16 body_size)
32 i2o_status_block *sb = c->status_block.virt;
33 u16 sg_count =
34 (sb->inbound_frame_size - sizeof(struct i2o_message) / 4) -
35 body_size;
37 if (c->pae_support) {
39 * for 64-bit a SG attribute element must be added and each
40 * SG element needs 12 bytes instead of 8.
42 sg_count -= 2;
43 sg_count /= 3;
44 } else
45 sg_count /= 2;
47 if (c->short_req && (sg_count > 8))
48 sg_count = 8;
50 return sg_count;
52 EXPORT_SYMBOL_GPL(i2o_sg_tablesize);
55 /**
56 * i2o_dma_map_single - Map pointer to controller and fill in I2O message.
57 * @c: I2O controller
58 * @ptr: pointer to the data which should be mapped
59 * @size: size of data in bytes
60 * @direction: DMA_TO_DEVICE / DMA_FROM_DEVICE
61 * @sg_ptr: pointer to the SG list inside the I2O message
63 * This function does all necessary DMA handling and also writes the I2O
64 * SGL elements into the I2O message. For details on DMA handling see also
65 * dma_map_single(). The pointer sg_ptr will only be set to the end of the
66 * SG list if the allocation was successful.
68 * Returns DMA address which must be checked for failures using
69 * dma_mapping_error().
71 dma_addr_t i2o_dma_map_single(struct i2o_controller *c, void *ptr,
72 size_t size,
73 enum dma_data_direction direction,
74 u32 ** sg_ptr)
76 u32 sg_flags;
77 u32 *mptr = *sg_ptr;
78 dma_addr_t dma_addr;
80 switch (direction) {
81 case DMA_TO_DEVICE:
82 sg_flags = 0xd4000000;
83 break;
84 case DMA_FROM_DEVICE:
85 sg_flags = 0xd0000000;
86 break;
87 default:
88 return 0;
91 dma_addr = dma_map_single(&c->pdev->dev, ptr, size, direction);
92 if (!dma_mapping_error(&c->pdev->dev, dma_addr)) {
93 #ifdef CONFIG_I2O_EXT_ADAPTEC_DMA64
94 if ((sizeof(dma_addr_t) > 4) && c->pae_support) {
95 *mptr++ = cpu_to_le32(0x7C020002);
96 *mptr++ = cpu_to_le32(PAGE_SIZE);
98 #endif
100 *mptr++ = cpu_to_le32(sg_flags | size);
101 *mptr++ = cpu_to_le32(i2o_dma_low(dma_addr));
102 #ifdef CONFIG_I2O_EXT_ADAPTEC_DMA64
103 if ((sizeof(dma_addr_t) > 4) && c->pae_support)
104 *mptr++ = cpu_to_le32(i2o_dma_high(dma_addr));
105 #endif
106 *sg_ptr = mptr;
108 return dma_addr;
110 EXPORT_SYMBOL_GPL(i2o_dma_map_single);
113 * i2o_dma_map_sg - Map a SG List to controller and fill in I2O message.
114 * @c: I2O controller
115 * @sg: SG list to be mapped
116 * @sg_count: number of elements in the SG list
117 * @direction: DMA_TO_DEVICE / DMA_FROM_DEVICE
118 * @sg_ptr: pointer to the SG list inside the I2O message
120 * This function does all necessary DMA handling and also writes the I2O
121 * SGL elements into the I2O message. For details on DMA handling see also
122 * dma_map_sg(). The pointer sg_ptr will only be set to the end of the SG
123 * list if the allocation was successful.
125 * Returns 0 on failure or 1 on success.
127 int i2o_dma_map_sg(struct i2o_controller *c, struct scatterlist *sg,
128 int sg_count, enum dma_data_direction direction, u32 ** sg_ptr)
130 u32 sg_flags;
131 u32 *mptr = *sg_ptr;
133 switch (direction) {
134 case DMA_TO_DEVICE:
135 sg_flags = 0x14000000;
136 break;
137 case DMA_FROM_DEVICE:
138 sg_flags = 0x10000000;
139 break;
140 default:
141 return 0;
144 sg_count = dma_map_sg(&c->pdev->dev, sg, sg_count, direction);
145 if (!sg_count)
146 return 0;
148 #ifdef CONFIG_I2O_EXT_ADAPTEC_DMA64
149 if ((sizeof(dma_addr_t) > 4) && c->pae_support) {
150 *mptr++ = cpu_to_le32(0x7C020002);
151 *mptr++ = cpu_to_le32(PAGE_SIZE);
153 #endif
155 while (sg_count-- > 0) {
156 if (!sg_count)
157 sg_flags |= 0xC0000000;
158 *mptr++ = cpu_to_le32(sg_flags | sg_dma_len(sg));
159 *mptr++ = cpu_to_le32(i2o_dma_low(sg_dma_address(sg)));
160 #ifdef CONFIG_I2O_EXT_ADAPTEC_DMA64
161 if ((sizeof(dma_addr_t) > 4) && c->pae_support)
162 *mptr++ = cpu_to_le32(i2o_dma_high(sg_dma_address(sg)));
163 #endif
164 sg = sg_next(sg);
166 *sg_ptr = mptr;
168 return 1;
170 EXPORT_SYMBOL_GPL(i2o_dma_map_sg);
173 * i2o_dma_alloc - Allocate DMA memory
174 * @dev: struct device pointer to the PCI device of the I2O controller
175 * @addr: i2o_dma struct which should get the DMA buffer
176 * @len: length of the new DMA memory
178 * Allocate a coherent DMA memory and write the pointers into addr.
180 * Returns 0 on success or -ENOMEM on failure.
182 int i2o_dma_alloc(struct device *dev, struct i2o_dma *addr, size_t len)
184 struct pci_dev *pdev = to_pci_dev(dev);
185 int dma_64 = 0;
187 mutex_lock(&mem_lock);
188 if ((sizeof(dma_addr_t) > 4) && (pdev->dma_mask == DMA_BIT_MASK(64))) {
189 dma_64 = 1;
190 if (pci_set_dma_mask(pdev, DMA_BIT_MASK(32))) {
191 mutex_unlock(&mem_lock);
192 return -ENOMEM;
196 addr->virt = dma_alloc_coherent(dev, len, &addr->phys, GFP_KERNEL);
198 if ((sizeof(dma_addr_t) > 4) && dma_64)
199 if (pci_set_dma_mask(pdev, DMA_BIT_MASK(64)))
200 printk(KERN_WARNING "i2o: unable to set 64-bit DMA");
201 mutex_unlock(&mem_lock);
203 if (!addr->virt)
204 return -ENOMEM;
206 memset(addr->virt, 0, len);
207 addr->len = len;
209 return 0;
211 EXPORT_SYMBOL_GPL(i2o_dma_alloc);
215 * i2o_dma_free - Free DMA memory
216 * @dev: struct device pointer to the PCI device of the I2O controller
217 * @addr: i2o_dma struct which contains the DMA buffer
219 * Free a coherent DMA memory and set virtual address of addr to NULL.
221 void i2o_dma_free(struct device *dev, struct i2o_dma *addr)
223 if (addr->virt) {
224 if (addr->phys)
225 dma_free_coherent(dev, addr->len, addr->virt,
226 addr->phys);
227 else
228 kfree(addr->virt);
229 addr->virt = NULL;
232 EXPORT_SYMBOL_GPL(i2o_dma_free);
236 * i2o_dma_realloc - Realloc DMA memory
237 * @dev: struct device pointer to the PCI device of the I2O controller
238 * @addr: pointer to a i2o_dma struct DMA buffer
239 * @len: new length of memory
241 * If there was something allocated in the addr, free it first. If len > 0
242 * than try to allocate it and write the addresses back to the addr
243 * structure. If len == 0 set the virtual address to NULL.
245 * Returns the 0 on success or negative error code on failure.
247 int i2o_dma_realloc(struct device *dev, struct i2o_dma *addr, size_t len)
249 i2o_dma_free(dev, addr);
251 if (len)
252 return i2o_dma_alloc(dev, addr, len);
254 return 0;
256 EXPORT_SYMBOL_GPL(i2o_dma_realloc);
259 * i2o_pool_alloc - Allocate an slab cache and mempool
260 * @mempool: pointer to struct i2o_pool to write data into.
261 * @name: name which is used to identify cache
262 * @size: size of each object
263 * @min_nr: minimum number of objects
265 * First allocates a slab cache with name and size. Then allocates a
266 * mempool which uses the slab cache for allocation and freeing.
268 * Returns 0 on success or negative error code on failure.
270 int i2o_pool_alloc(struct i2o_pool *pool, const char *name,
271 size_t size, int min_nr)
273 pool->name = kmalloc(strlen(name) + 1, GFP_KERNEL);
274 if (!pool->name)
275 goto exit;
276 strcpy(pool->name, name);
278 pool->slab =
279 kmem_cache_create(pool->name, size, 0, SLAB_HWCACHE_ALIGN, NULL);
280 if (!pool->slab)
281 goto free_name;
283 pool->mempool = mempool_create_slab_pool(min_nr, pool->slab);
284 if (!pool->mempool)
285 goto free_slab;
287 return 0;
289 free_slab:
290 kmem_cache_destroy(pool->slab);
292 free_name:
293 kfree(pool->name);
295 exit:
296 return -ENOMEM;
298 EXPORT_SYMBOL_GPL(i2o_pool_alloc);
301 * i2o_pool_free - Free slab cache and mempool again
302 * @mempool: pointer to struct i2o_pool which should be freed
304 * Note that you have to return all objects to the mempool again before
305 * calling i2o_pool_free().
307 void i2o_pool_free(struct i2o_pool *pool)
309 mempool_destroy(pool->mempool);
310 kmem_cache_destroy(pool->slab);
311 kfree(pool->name);
313 EXPORT_SYMBOL_GPL(i2o_pool_free);