/** * Copyright (C) 2008, Creative Technology Ltd. All Rights Reserved. * * This source file is released under GPL v2 license (no other versions). * See the COPYING file included in the main directory of this source * distribution for the license terms and conditions. * * @File ctvmem.c * * @Brief * This file contains the implementation of virtual memory management object * for card device. * * @Author Liu Chun * @Date Apr 1 2008 */ #include "ctvmem.h" #include <linux/slab.h> #include <linux/mm.h> #include <linux/io.h> #include <sound/pcm.h> #define CT_PTES_PER_PAGE (CT_PAGE_SIZE / sizeof(void *)) #define CT_ADDRS_PER_PAGE (CT_PTES_PER_PAGE * CT_PAGE_SIZE) /* * * Find or create vm block based on requested @size. * @size must be page aligned. * */ static struct ct_vm_block * get_vm_block(struct ct_vm *vm, unsigned int size) { struct ct_vm_block *block = NULL, *entry; struct list_head *pos; size = CT_PAGE_ALIGN(size); if (size > vm->size) { printk(KERN_ERR "ctxfi: Fail! No sufficient device virtural " "memory space available!\n"); return NULL; } mutex_lock(&vm->lock); list_for_each(pos, &vm->unused) { entry = list_entry(pos, struct ct_vm_block, list); if (entry->size >= size) break; /* found a block that is big enough */ } if (pos == &vm->unused) goto out; if (entry->size == size) { /* Move the vm node from unused list to used list directly */ list_move(&entry->list, &vm->used); vm->size -= size; block = entry; goto out; } block = kzalloc(sizeof(*block), GFP_KERNEL); if (!block) goto out; block->addr = entry->addr; block->size = size; list_add(&block->list, &vm->used); entry->addr += size; entry->size -= size; vm->size -= size; out: mutex_unlock(&vm->lock); return block; } static void put_vm_block(struct ct_vm *vm, struct ct_vm_block *block) { struct ct_vm_block *entry, *pre_ent; struct list_head *pos, *pre; block->size = CT_PAGE_ALIGN(block->size); mutex_lock(&vm->lock); list_del(&block->list); vm->size += block->size; list_for_each(pos, &vm->unused) { entry = list_entry(pos, struct ct_vm_block, list); if (entry->addr >= (block->addr + block->size)) break; /* found a position */ } if (pos == &vm->unused) { list_add_tail(&block->list, &vm->unused); entry = block; } else { if ((block->addr + block->size) == entry->addr) { entry->addr = block->addr; entry->size += block->size; kfree(block); } else { __list_add(&block->list, pos->prev, pos); entry = block; } } pos = &entry->list; pre = pos->prev; while (pre != &vm->unused) { entry = list_entry(pos, struct ct_vm_block, list); pre_ent = list_entry(pre, struct ct_vm_block, list); if ((pre_ent->addr + pre_ent->size) > entry->addr) break; pre_ent->size += entry->size; list_del(pos); kfree(entry); pos = pre; pre = pos->prev; } mutex_unlock(&vm->lock); } /* Map host addr (kmalloced/vmalloced) to device logical addr. */ static struct ct_vm_block * ct_vm_map(struct ct_vm *vm, struct snd_pcm_substream *substream, int size) { struct ct_vm_block *block; unsigned int pte_start; unsigned i, pages; unsigned long *ptp; block = get_vm_block(vm, size); if (block == NULL) { printk(KERN_ERR "ctxfi: No virtual memory block that is big " "enough to allocate!\n"); return NULL; } ptp = (unsigned long *)vm->ptp[0].area; pte_start = (block->addr >> CT_PAGE_SHIFT); pages = block->size >> CT_PAGE_SHIFT; for (i = 0; i < pages; i++) { unsigned long addr; addr = snd_pcm_sgbuf_get_addr(substream, i << CT_PAGE_SHIFT); ptp[pte_start + i] = addr; } block->size = size; return block; } static void ct_vm_unmap(struct ct_vm *vm, struct ct_vm_block *block) { /* do unmapping */ put_vm_block(vm, block); } /* * * return the host physical addr of the @index-th device * page table page on success, or ~0UL on failure. * The first returned ~0UL indicates the termination. * */ static dma_addr_t ct_get_ptp_phys(struct ct_vm *vm, int index) { dma_addr_t addr; addr = (index >= CT_PTP_NUM) ? ~0UL : vm->ptp[index].addr; return addr; } int ct_vm_create(struct ct_vm **rvm, struct pci_dev *pci) { struct ct_vm *vm; struct ct_vm_block *block; int i, err = 0; *rvm = NULL; vm = kzalloc(sizeof(*vm), GFP_KERNEL); if (!vm) return -ENOMEM; mutex_init(&vm->lock); /* Allocate page table pages */ for (i = 0; i < CT_PTP_NUM; i++) { err = snd_dma_alloc_pages(SNDRV_DMA_TYPE_DEV, snd_dma_pci_data(pci), PAGE_SIZE, &vm->ptp[i]); if (err < 0) break; } if (err < 0) { /* no page table pages are allocated */ ct_vm_destroy(vm); return -ENOMEM; } vm->size = CT_ADDRS_PER_PAGE * i; vm->map = ct_vm_map; vm->unmap = ct_vm_unmap; vm->get_ptp_phys = ct_get_ptp_phys; INIT_LIST_HEAD(&vm->unused); INIT_LIST_HEAD(&vm->used); block = kzalloc(sizeof(*block), GFP_KERNEL); if (NULL != block) { block->addr = 0; block->size = vm->size; list_add(&block->list, &vm->unused); } *rvm = vm; return 0; } /* The caller must ensure no mapping pages are being used * by hardware before calling this function */ void ct_vm_destroy(struct ct_vm *vm) { int i; struct list_head *pos; struct ct_vm_block *entry; /* free used and unused list nodes */ while (!list_empty(&vm->used)) { pos = vm->used.next; list_del(pos); entry = list_entry(pos, struct ct_vm_block, list); kfree(entry); } while (!list_empty(&vm->unused)) { pos = vm->unused.next; list_del(pos); entry = list_entry(pos, struct ct_vm_block, list); kfree(entry); } /* free allocated page table pages */ for (i = 0; i < CT_PTP_NUM; i++) snd_dma_free_pages(&vm->ptp[i]); vm->size = 0; kfree(vm); }