kernel/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 "ctatc.h"
  20 #include <linux/slab.h>
  21 #include <linux/mm.h>
  22 #include <linux/io.h>
  23 #include <sound/pcm.h>
  24
  25 #define CT_PTES_PER_PAGE (CT_PAGE_SIZE / sizeof(void *))
  26 #define CT_ADDRS_PER_PAGE (CT_PTES_PER_PAGE * CT_PAGE_SIZE)
  27
  28 /* *
  29  * Find or create vm block based on requested @size.
  30  * @size must be page aligned.
  31  * */
  32 static struct ct_vm_block *
  33 get_vm_block(struct ct_vm *vm, unsigned int size, struct ct_atc *atc)
  34 {
  35         struct ct_vm_block *block = NULL, *entry;
  36         struct list_head *pos;
  37
  38         size = CT_PAGE_ALIGN(size);
  39         if (size > vm->size) {
  40                 dev_err(atc->card->dev,
  41                         "Fail! No sufficient device virtual memory space available!\n");
  42                 return NULL;
  43         }
  44
  45         mutex_lock(&vm->lock);
  46         list_for_each(pos, &vm->unused) {
  47                 entry = list_entry(pos, struct ct_vm_block, list);
  48                 if (entry->size >= size)
  49                         break; /* found a block that is big enough */
  50         }
  51         if (pos == &vm->unused)
  52                 goto out;
  53
  54         if (entry->size == size) {
  55                 /* Move the vm node from unused list to used list directly */
  56                 list_move(&entry->list, &vm->used);
  57                 vm->size -= size;
  58                 block = entry;
  59                 goto out;
  60         }
  61
  62         block = kzalloc(sizeof(*block), GFP_KERNEL);
  63         if (!block)
  64                 goto out;
  65
  66         block->addr = entry->addr;
  67         block->size = size;
  68         list_add(&block->list, &vm->used);
  69         entry->addr += size;
  70         entry->size -= size;
  71         vm->size -= size;
  72
  73  out:
  74         mutex_unlock(&vm->lock);
  75         return block;
  76 }
  77
  78 static void put_vm_block(struct ct_vm *vm, struct ct_vm_block *block)
  79 {
  80         struct ct_vm_block *entry, *pre_ent;
  81         struct list_head *pos, *pre;
  82
  83         block->size = CT_PAGE_ALIGN(block->size);
  84
  85         mutex_lock(&vm->lock);
  86         list_del(&block->list);
  87         vm->size += block->size;
  88
  89         list_for_each(pos, &vm->unused) {
  90                 entry = list_entry(pos, struct ct_vm_block, list);
  91                 if (entry->addr >= (block->addr + block->size))
  92                         break; /* found a position */
  93         }
  94         if (pos == &vm->unused) {
  95                 list_add_tail(&block->list, &vm->unused);
  96                 entry = block;
  97         } else {
  98                 if ((block->addr + block->size) == entry->addr) {
  99                         entry->addr = block->addr;
 100                         entry->size += block->size;
 101                         kfree(block);
 102                 } else {
 103                         __list_add(&block->list, pos->prev, pos);
 104                         entry = block;
 105                 }
 106         }
 107
 108         pos = &entry->list;
 109         pre = pos->prev;
 110         while (pre != &vm->unused) {
 111                 entry = list_entry(pos, struct ct_vm_block, list);
 112                 pre_ent = list_entry(pre, struct ct_vm_block, list);
 113                 if ((pre_ent->addr + pre_ent->size) > entry->addr)
 114                         break;
 115
 116                 pre_ent->size += entry->size;
 117                 list_del(pos);
 118                 kfree(entry);
 119                 pos = pre;
 120                 pre = pos->prev;
 121         }
 122         mutex_unlock(&vm->lock);
 123 }
 124
 125 /* Map host addr (kmalloced/vmalloced) to device logical addr. */
 126 static struct ct_vm_block *
 127 ct_vm_map(struct ct_vm *vm, struct snd_pcm_substream *substream, int size)
 128 {
 129         struct ct_vm_block *block;
 130         unsigned int pte_start;
 131         unsigned i, pages;
 132         unsigned long *ptp;
 133         struct ct_atc *atc = snd_pcm_substream_chip(substream);
 134
 135         block = get_vm_block(vm, size, atc);
 136         if (block == NULL) {
 137                 dev_err(atc->card->dev,
 138                         "No virtual memory block that is big enough to allocate!\n");
 139                 return NULL;
 140         }
 141
 142         ptp = (unsigned long *)vm->ptp[0].area;
 143         pte_start = (block->addr >> CT_PAGE_SHIFT);
 144         pages = block->size >> CT_PAGE_SHIFT;
 145         for (i = 0; i < pages; i++) {
 146                 unsigned long addr;
 147                 addr = snd_pcm_sgbuf_get_addr(substream, i << CT_PAGE_SHIFT);
 148                 ptp[pte_start + i] = addr;
 149         }
 150
 151         block->size = size;
 152         return block;
 153 }
 154
 155 static void ct_vm_unmap(struct ct_vm *vm, struct ct_vm_block *block)
 156 {
 157         /* do unmapping */
 158         put_vm_block(vm, block);
 159 }
 160
 161 /* *
 162  * return the host physical addr of the @index-th device
 163  * page table page on success, or ~0UL on failure.
 164  * The first returned ~0UL indicates the termination.
 165  * */
 166 static dma_addr_t
 167 ct_get_ptp_phys(struct ct_vm *vm, int index)
 168 {
 169         dma_addr_t addr;
 170
 171         addr = (index >= CT_PTP_NUM) ? ~0UL : vm->ptp[index].addr;
 172
 173         return addr;
 174 }
 175
 176 int ct_vm_create(struct ct_vm **rvm, struct pci_dev *pci)
 177 {
 178         struct ct_vm *vm;
 179         struct ct_vm_block *block;
 180         int i, err = 0;
 181
 182         *rvm = NULL;
 183
 184         vm = kzalloc(sizeof(*vm), GFP_KERNEL);
 185         if (!vm)
 186                 return -ENOMEM;
 187
 188         mutex_init(&vm->lock);
 189
 190         /* Allocate page table pages */
 191         for (i = 0; i < CT_PTP_NUM; i++) {
 192                 err = snd_dma_alloc_pages(SNDRV_DMA_TYPE_DEV,
 193                                           snd_dma_pci_data(pci),
 194                                           PAGE_SIZE, &vm->ptp[i]);
 195                 if (err < 0)
 196                         break;
 197         }
 198         if (err < 0) {
 199                 /* no page table pages are allocated */
 200                 ct_vm_destroy(vm);
 201                 return -ENOMEM;
 202         }
 203         vm->size = CT_ADDRS_PER_PAGE * i;
 204         vm->map = ct_vm_map;
 205         vm->unmap = ct_vm_unmap;
 206         vm->get_ptp_phys = ct_get_ptp_phys;
 207         INIT_LIST_HEAD(&vm->unused);
 208         INIT_LIST_HEAD(&vm->used);
 209         block = kzalloc(sizeof(*block), GFP_KERNEL);
 210         if (NULL != block) {
 211                 block->addr = 0;
 212                 block->size = vm->size;
 213                 list_add(&block->list, &vm->unused);
 214         }
 215
 216         *rvm = vm;
 217         return 0;
 218 }
 219
 220 /* The caller must ensure no mapping pages are being used
 221  * by hardware before calling this function */
 222 void ct_vm_destroy(struct ct_vm *vm)
 223 {
 224         int i;
 225         struct list_head *pos;
 226         struct ct_vm_block *entry;
 227
 228         /* free used and unused list nodes */
 229         while (!list_empty(&vm->used)) {
 230                 pos = vm->used.next;
 231                 list_del(pos);
 232                 entry = list_entry(pos, struct ct_vm_block, list);
 233                 kfree(entry);
 234         }
 235         while (!list_empty(&vm->unused)) {
 236                 pos = vm->unused.next;
 237                 list_del(pos);
 238                 entry = list_entry(pos, struct ct_vm_block, list);
 239                 kfree(entry);
 240         }
 241
 242         /* free allocated page table pages */
 243         for (i = 0; i < CT_PTP_NUM; i++)
 244                 snd_dma_free_pages(&vm->ptp[i]);
 245
 246         vm->size = 0;
 247
 248         kfree(vm);
 249 }