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