1 files changed, 250 insertions, 0 deletions
diff --git a/sound/pci/ctxfi/ctvmem.c b/sound/pci/ctxfi/ctvmem.c
new file mode 100644
index 0000000..67665a7
--- /dev/null
+++ b/sound/pci/ctxfi/ctvmem.c
@@ -0,0 +1,250 @@
+/**
+ * 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_del(&entry->list);
+		list_add(&entry->list, &vm->used);
+		vm->size -= size;
+		block = entry;
+		goto out;
+	}
+
+	block = kzalloc(sizeof(*block), GFP_KERNEL);
+	if (NULL == 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 = vm->ptp[0];
+	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 (kmalloced) addr of the @index-th device
+ * page talbe page on success, or NULL on failure.
+ * The first returned NULL indicates the termination.
+ * */
+static void *
+ct_get_ptp_virt(struct ct_vm *vm, int index)
+{
+	void *addr;
+
+	addr = (index >= CT_PTP_NUM) ? NULL : vm->ptp[index];
+
+	return addr;
+}
+
+int ct_vm_create(struct ct_vm **rvm)
+{
+	struct ct_vm *vm;
+	struct ct_vm_block *block;
+	int i;
+
+	*rvm = NULL;
+
+	vm = kzalloc(sizeof(*vm), GFP_KERNEL);
+	if (NULL == vm)
+		return -ENOMEM;
+
+	mutex_init(&vm->lock);
+
+	/* Allocate page table pages */
+	for (i = 0; i < CT_PTP_NUM; i++) {
+		vm->ptp[i] = kmalloc(PAGE_SIZE, GFP_KERNEL);
+		if (NULL == vm->ptp[i])
+			break;
+	}
+	if (!i) {
+		/* no page table pages are allocated */
+		kfree(vm);
+		return -ENOMEM;
+	}
+	vm->size = CT_ADDRS_PER_PAGE * i;
+	/* Initialise remaining ptps */
+	for (; i < CT_PTP_NUM; i++)
+		vm->ptp[i] = NULL;
+
+	vm->map = ct_vm_map;
+	vm->unmap = ct_vm_unmap;
+	vm->get_ptp_virt = ct_get_ptp_virt;
+	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++)
+		kfree(vm->ptp[i]);
+
+	vm->size = 0;
+
+	kfree(vm);
+}