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 <asm/pgtable.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 = NULL;
  35         struct list_head *pos = NULL;
  36
  37         mutex_lock(&vm->lock);
  38         list_for_each(pos, &vm->unused) {
  39                 entry = list_entry(pos, struct ct_vm_block, list);
  40                 if (entry->size >= size)
  41                         break; /* found a block that is big enough */
  42         }
  43         if (pos == &vm->unused)
  44                 goto out;
  45
  46         if (entry->size == size) {
  47                 /* Move the vm node from unused list to used list directly */
  48                 list_del(&entry->list);
  49                 list_add(&entry->list, &vm->used);
  50                 vm->size -= size;
  51                 block = entry;
  52                 goto out;
  53         }
  54
  55         block = kzalloc(sizeof(*block), GFP_KERNEL);
  56         if (NULL == block)
  57                 goto out;
  58
  59         block->addr = entry->addr;
  60         block->size = size;
  61         list_add(&block->list, &vm->used);
  62         entry->addr += size;
  63         entry->size -= size;
  64         vm->size -= size;
  65
  66  out:
  67         mutex_unlock(&vm->lock);
  68         return block;
  69 }
  70
  71 static void put_vm_block(struct ct_vm *vm, struct ct_vm_block *block)
  72 {
  73         struct ct_vm_block *entry = NULL, *pre_ent = NULL;
  74         struct list_head *pos = NULL, *pre = NULL;
  75
  76         mutex_lock(&vm->lock);
  77         list_del(&block->list);
  78         vm->size += block->size;
  79
  80         list_for_each(pos, &vm->unused) {
  81                 entry = list_entry(pos, struct ct_vm_block, list);
  82                 if (entry->addr >= (block->addr + block->size))
  83                         break; /* found a position */
  84         }
  85         if (pos == &vm->unused) {
  86                 list_add_tail(&block->list, &vm->unused);
  87                 entry = block;
  88         } else {
  89                 if ((block->addr + block->size) == entry->addr) {
  90                         entry->addr = block->addr;
  91                         entry->size += block->size;
  92                         kfree(block);
  93                 } else {
  94                         __list_add(&block->list, pos->prev, pos);
  95                         entry = block;
  96                 }
  97         }
  98
  99         pos = &entry->list;
 100         pre = pos->prev;
 101         while (pre != &vm->unused) {
 102                 entry = list_entry(pos, struct ct_vm_block, list);
 103                 pre_ent = list_entry(pre, struct ct_vm_block, list);
 104                 if ((pre_ent->addr + pre_ent->size) > entry->addr)
 105                         break;
 106
 107                 pre_ent->size += entry->size;
 108                 list_del(pos);
 109                 kfree(entry);
 110                 pos = pre;
 111                 pre = pos->prev;
 112         }
 113         mutex_unlock(&vm->lock);
 114 }
 115
 116 /* Map host addr (kmalloced/vmalloced) to device logical addr. */
 117 static struct ct_vm_block *
 118 ct_vm_map(struct ct_vm *vm, void *host_addr, int size)
 119 {
 120         struct ct_vm_block *block = NULL;
 121         unsigned long pte_start;
 122         unsigned long i;
 123         unsigned long pages;
 124         unsigned long start_phys;
 125         unsigned long *ptp;
 126
 127         /* do mapping */
 128         if ((unsigned long)host_addr >= VMALLOC_START) {
 129                 printk(KERN_ERR "ctxfi: "
 130                        "Fail! Not support vmalloced addr now!\n");
 131                 return NULL;
 132         }
 133
 134         if (size > vm->size) {
 135                 printk(KERN_ERR "ctxfi: Fail! No sufficient device virtural "
 136                                   "memory space available!\n");
 137                 return NULL;
 138         }
 139
 140         start_phys = (virt_to_phys(host_addr) & CT_PAGE_MASK);
 141         pages = (CT_PAGE_ALIGN(virt_to_phys(host_addr) + size)
 142                         - start_phys) >> CT_PAGE_SHIFT;
 143
 144         ptp = vm->ptp[0];
 145
 146         block = get_vm_block(vm, (pages << CT_PAGE_SHIFT));
 147         if (block == NULL) {
 148                 printk(KERN_ERR "ctxfi: No virtual memory block that is big "
 149                                   "enough to allocate!\n");
 150                 return NULL;
 151         }
 152
 153         pte_start = (block->addr >> CT_PAGE_SHIFT);
 154         for (i = 0; i < pages; i++)
 155                 ptp[pte_start+i] = start_phys + (i << CT_PAGE_SHIFT);
 156
 157         block->addr += (virt_to_phys(host_addr) & (~CT_PAGE_MASK));
 158         block->size = size;
 159
 160         return block;
 161 }
 162
 163 static void ct_vm_unmap(struct ct_vm *vm, struct ct_vm_block *block)
 164 {
 165         /* do unmapping */
 166         block->size = ((block->addr + block->size + CT_PAGE_SIZE - 1)
 167                         & CT_PAGE_MASK) - (block->addr & CT_PAGE_MASK);
 168         block->addr &= CT_PAGE_MASK;
 169         put_vm_block(vm, block);
 170 }
 171
 172 /* *
 173  * return the host (kmalloced) addr of the @index-th device
 174  * page talbe page on success, or NULL on failure.
 175  * The first returned NULL indicates the termination.
 176  * */
 177 static void *
 178 ct_get_ptp_virt(struct ct_vm *vm, int index)
 179 {
 180         void *addr;
 181
 182         addr = (index >= CT_PTP_NUM) ? NULL : vm->ptp[index];
 183
 184         return addr;
 185 }
 186
 187 int ct_vm_create(struct ct_vm **rvm)
 188 {
 189         struct ct_vm *vm;
 190         struct ct_vm_block *block;
 191         int i;
 192
 193         *rvm = NULL;
 194
 195         vm = kzalloc(sizeof(*vm), GFP_KERNEL);
 196         if (NULL == vm)
 197                 return -ENOMEM;
 198
 199         mutex_init(&vm->lock);
 200
 201         /* Allocate page table pages */
 202         for (i = 0; i < CT_PTP_NUM; i++) {
 203                 vm->ptp[i] = kmalloc(PAGE_SIZE, GFP_KERNEL);
 204                 if (NULL == vm->ptp[i])
 205                         break;
 206         }
 207         if (!i) {
 208                 /* no page table pages are allocated */
 209                 kfree(vm);
 210                 return -ENOMEM;
 211         }
 212         vm->size = CT_ADDRS_PER_PAGE * i;
 213         /* Initialise remaining ptps */
 214         for (; i < CT_PTP_NUM; i++)
 215                 vm->ptp[i] = NULL;
 216
 217         vm->map = ct_vm_map;
 218         vm->unmap = ct_vm_unmap;
 219         vm->get_ptp_virt = ct_get_ptp_virt;
 220         INIT_LIST_HEAD(&vm->unused);
 221         INIT_LIST_HEAD(&vm->used);
 222         block = kzalloc(sizeof(*block), GFP_KERNEL);
 223         if (NULL != block) {
 224                 block->addr = 0;
 225                 block->size = vm->size;
 226                 list_add(&block->list, &vm->unused);
 227         }
 228
 229         *rvm = vm;
 230         return 0;
 231 }
 232
 233 /* The caller must ensure no mapping pages are being used
 234  * by hardware before calling this function */
 235 void ct_vm_destroy(struct ct_vm *vm)
 236 {
 237         int i;
 238         struct list_head *pos = NULL;
 239         struct ct_vm_block *entry = NULL;
 240
 241         /* free used and unused list nodes */
 242         while (!list_empty(&vm->used)) {
 243                 pos = vm->used.next;
 244                 list_del(pos);
 245                 entry = list_entry(pos, struct ct_vm_block, list);
 246                 kfree(entry);
 247         }
 248         while (!list_empty(&vm->unused)) {
 249                 pos = vm->unused.next;
 250                 list_del(pos);
 251                 entry = list_entry(pos, struct ct_vm_block, list);
 252                 kfree(entry);
 253         }
 254
 255         /* free allocated page table pages */
 256         for (i = 0; i < CT_PTP_NUM; i++)
 257                 kfree(vm->ptp[i]);
 258
 259         vm->size = 0;
 260
 261         kfree(vm);
 262 }