sound/pci/ctxfi/ctvmem.c

Source file repositories/reference/linux-study-clean/sound/pci/ctxfi/ctvmem.c

File Facts

System
Linux kernel
Corpus path
sound/pci/ctxfi/ctvmem.c
Extension
.c
Size
5452 bytes
Lines
239
Domain
Driver Families
Bucket
sound/pci
Inferred role
Driver Families: implementation source
Status
source implementation candidate

Why This File Exists

Repeatable hardware-adapter layer. Deep compatibility for every driver is out of scope; this atlas records patterns, probe lifecycles, bus glue, IRQ/DMA usage, and links back to core abstractions.

Dependency Surface

Detected Declarations

Annotated Snippet

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;
	}
}

/* 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;
	struct ct_atc *atc = snd_pcm_substream_chip(substream);

	block = get_vm_block(vm, size, atc);
	if (block == NULL) {
		dev_err(atc->card->dev,
			"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)
{
	return (index >= CT_PTP_NUM) ? ~0UL : vm->ptp[index].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_obj(*vm);
	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,

Annotation

Implementation Notes