sound/pci/ctxfi/ctvmem.c

   1 /**
   2  * Copyright (C) 2008, Creative Technology Ltd. All Rights Reserved.
   3  *
   4  * This source file is released under GPL v2 license (no other versions).
   5  * See the COPYING file included in the main directory of this source
   6  * distribution for the license terms and conditions.
   7  *
   8  * @File    ctvmem.c
   9  *
  10  * @Brief
  11  * This file contains the implementation of virtual memory management object
  12  * for card device.
  13  *
  14  * @Author Liu Chun
  15  * @Date Apr 1 2008
  16  */
  17
  18 #include "ctvmem.h"
  19 #include <linux/slab.h>
  20 #include <linux/mm.h>
  21 #include <linux/io.h>
  22 #include <sound/pcm.h>
  23
  24 #define CT_PTES_PER_PAGE (CT_PAGE_SIZE / sizeof(void *))
  25 #define CT_ADDRS_PER_PAGE (CT_PTES_PER_PAGE * CT_PAGE_SIZE)
  26
  27 /* *
  28  * Find or create vm block based on requested @size.
  29  * @size must be page aligned.
  30  * */
  31 static struct ct_vm_block *
  32 get_vm_block(struct ct_vm *vm, unsigned int size)
  33 {
  34         struct ct_vm_block *block = NULL, *entry;
  35         struct list_head *pos;
  36
  37         size = CT_PAGE_ALIGN(size);
  38         if (size > vm->size) {
  39                 printk(KERN_ERR "ctxfi: Fail! No sufficient device virtural "
  40                                   "memory space available!\n");
  41                 return NULL;
  42         }
  43
  44         mutex_lock(&vm->lock);
  45         list_for_each(pos, &vm->unused) {
  46                 entry = list_entry(pos, struct ct_vm_block, list);
  47                 if (entry->size >= size)
  48                         break; /* found a block that is big enough */
  49         }
  50         if (pos == &vm->unused)
  51                 goto out;
  52
  53         if (entry->size == size) {
  54                 /* Move the vm node from unused list to used list directly */
  55                 list_move(&entry->list, &vm->used);
  56                 vm->size -= size;
  57                 block = entry;
  58                 goto out;
  59         }
  60
  61         block = kzalloc(sizeof(*block), GFP_KERNEL);
  62         if (!block)
  63                 goto out;
  64
  65         block->addr = entry->addr;
  66         block->size = size;
  67         list_add(&block->list, &vm->used);
  68         entry->addr += size;
  69         entry->size -= size;
  70         vm->size -= size;
  71
  72  out:
  73         mutex_unlock(&vm->lock);
  74         return block;
  75 }
  76
  77 static void put_vm_block(struct ct_vm *vm, struct ct_vm_block *block)
  78 {
  79         struct ct_vm_block *entry, *pre_ent;
  80         struct list_head *pos, *pre;
  81
  82         block->size = CT_PAGE_ALIGN(block->size);
  83
  84         mutex_lock(&vm->lock);
  85         list_del(&block->list);
  86         vm->size += block->size;
  87
  88         list_for_each(pos, &vm->unused) {
  89                 entry = list_entry(pos, struct ct_vm_block, list);
  90                 if (entry->addr >= (block->addr + block->size))
  91                         break; /* found a position */
  92         }
  93         if (pos == &vm->unused) {
  94                 list_add_tail(&block->list, &vm->unused);
  95                 entry = block;
  96         } else {
  97                 if ((block->addr + block->size) == entry->addr) {
  98                         entry->addr = block->addr;
  99                         entry->size += block->size;
 100                         kfree(block);
 101                 } else {
 102                         __list_add(&block->list, pos->prev, pos);
 103                         entry = block;
 104                 }
 105         }
 106
 107         pos = &entry->list;
 108         pre = pos->prev;
 109         while (pre != &vm->unused) {
 110                 entry = list_entry(pos, struct ct_vm_block, list);
 111                 pre_ent = list_entry(pre, struct ct_vm_block, list);
 112                 if ((pre_ent->addr + pre_ent->size) > entry->addr)
 113                         break;
 114
 115                 pre_ent->size += entry->size;
 116                 list_del(pos);
 117                 kfree(entry);
 118                 pos = pre;
 119                 pre = pos->prev;
 120         }
 121         mutex_unlock(&vm->lock);
 122 }
 123
 124 /* Map host addr (kmalloced/vmalloced) to device logical addr. */
 125 static struct ct_vm_block *
 126 ct_vm_map(struct ct_vm *vm, struct snd_pcm_substream *substream, int size)
 127 {
 128         struct ct_vm_block *block;
 129         unsigned int pte_start;
 130         unsigned i, pages;
 131         unsigned long *ptp;
 132
 133         block = get_vm_block(vm, size);
 134         if (block == NULL) {
 135                 printk(KERN_ERR "ctxfi: No virtual memory block that is big "
 136                                   "enough to allocate!\n");
 137                 return NULL;
 138         }
 139
 140         ptp = (unsigned long *)vm->ptp[0].area;
 141         pte_start = (block->addr >> CT_PAGE_SHIFT);
 142         pages = block->size >> CT_PAGE_SHIFT;
 143         for (i = 0; i < pages; i++) {
 144                 unsigned long addr;
 145                 addr = snd_pcm_sgbuf_get_addr(substream, i << CT_PAGE_SHIFT);
 146                 ptp[pte_start + i] = addr;
 147         }
 148
 149         block->size = size;
 150         return block;
 151 }
 152
 153 static void ct_vm_unmap(struct ct_vm *vm, struct ct_vm_block *block)
 154 {
 155         /* do unmapping */
 156         put_vm_block(vm, block);
 157 }
 158
 159 /* *
 160  * return the host physical addr of the @index-th device
 161  * page table page on success, or ~0UL on failure.
 162  * The first returned ~0UL indicates the termination.
 163  * */
 164 static dma_addr_t
 165 ct_get_ptp_phys(struct ct_vm *vm, int index)
 166 {
 167         dma_addr_t addr;
 168
 169         addr = (index >= CT_PTP_NUM) ? ~0UL : vm->ptp[index].addr;
 170
 171         return addr;
 172 }
 173
 174 int ct_vm_create(struct ct_vm **rvm, struct pci_dev *pci)
 175 {
 176         struct ct_vm *vm;
 177         struct ct_vm_block *block;
 178         int i, err = 0;
 179
 180         *rvm = NULL;
 181
 182         vm = kzalloc(sizeof(*vm), GFP_KERNEL);
 183         if (!vm)
 184                 return -ENOMEM;
 185
 186         mutex_init(&vm->lock);
 187
 188         /* Allocate page table pages */
 189         for (i = 0; i < CT_PTP_NUM; i++) {
 190                 err = snd_dma_alloc_pages(SNDRV_DMA_TYPE_DEV,
 191                                           snd_dma_pci_data(pci),
 192                                           PAGE_SIZE, &vm->ptp[i]);
 193                 if (err < 0)
 194                         break;
 195         }
 196         if (err < 0) {
 197                 /* no page table pages are allocated */
 198                 ct_vm_destroy(vm);
 199                 return -ENOMEM;
 200         }
 201         vm->size = CT_ADDRS_PER_PAGE * i;
 202         vm->map = ct_vm_map;
 203         vm->unmap = ct_vm_unmap;
 204         vm->get_ptp_phys = ct_get_ptp_phys;
 205         INIT_LIST_HEAD(&vm->unused);
 206         INIT_LIST_HEAD(&vm->used);
 207         block = kzalloc(sizeof(*block), GFP_KERNEL);
 208         if (NULL != block) {
 209                 block->addr = 0;
 210                 block->size = vm->size;
 211                 list_add(&block->list, &vm->unused);
 212         }
 213
 214         *rvm = vm;
 215         return 0;
 216 }
 217
 218 /* The caller must ensure no mapping pages are being used
 219  * by hardware before calling this function */
 220 void ct_vm_destroy(struct ct_vm *vm)
 221 {
 222         int i;
 223         struct list_head *pos;
 224         struct ct_vm_block *entry;
 225
 226         /* free used and unused list nodes */
 227         while (!list_empty(&vm->used)) {
 228                 pos = vm->used.next;
 229                 list_del(pos);
 230                 entry = list_entry(pos, struct ct_vm_block, list);
 231                 kfree(entry);
 232         }
 233         while (!list_empty(&vm->unused)) {
 234                 pos = vm->unused.next;
 235                 list_del(pos);
 236                 entry = list_entry(pos, struct ct_vm_block, list);
 237                 kfree(entry);
 238         }
 239
 240         /* free allocated page table pages */
 241         for (i = 0; i < CT_PTP_NUM; i++)
 242                 snd_dma_free_pages(&vm->ptp[i]);
 243
 244         vm->size = 0;
 245
 246         kfree(vm);
 247 }