xref: /linux/sound/pci/ctxfi/ctvmem.c (revision 68a052239fc4b351e961f698b824f7654a346091)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Copyright (C) 2008, Creative Technology Ltd. All Rights Reserved.
4  *
5  * @File    ctvmem.c
6  *
7  * @Brief
8  * This file contains the implementation of virtual memory management object
9  * for card device.
10  *
11  * @Author Liu Chun
12  * @Date Apr 1 2008
13  */
14 
15 #include "ctvmem.h"
16 #include "ctatc.h"
17 #include <linux/slab.h>
18 #include <linux/mm.h>
19 #include <linux/io.h>
20 #include <sound/pcm.h>
21 
22 #define CT_PTES_PER_PAGE (CT_PAGE_SIZE / sizeof(void *))
23 #define CT_ADDRS_PER_PAGE (CT_PTES_PER_PAGE * CT_PAGE_SIZE)
24 
25 /* *
26  * Find or create vm block based on requested @size.
27  * @size must be page aligned.
28  * */
29 static struct ct_vm_block *
30 get_vm_block(struct ct_vm *vm, unsigned int size, struct ct_atc *atc)
31 {
32 	struct ct_vm_block *block, *entry;
33 	struct list_head *pos;
34 
35 	size = CT_PAGE_ALIGN(size);
36 	if (size > vm->size) {
37 		dev_err(atc->card->dev,
38 			"Fail! No sufficient device virtual memory space available!\n");
39 		return NULL;
40 	}
41 
42 	guard(mutex)(&vm->lock);
43 	list_for_each(pos, &vm->unused) {
44 		entry = list_entry(pos, struct ct_vm_block, list);
45 		if (entry->size >= size)
46 			break; /* found a block that is big enough */
47 	}
48 	if (pos == &vm->unused)
49 		return NULL;
50 
51 	if (entry->size == size) {
52 		/* Move the vm node from unused list to used list directly */
53 		list_move(&entry->list, &vm->used);
54 		vm->size -= size;
55 		return entry;
56 	}
57 
58 	block = kzalloc(sizeof(*block), GFP_KERNEL);
59 	if (!block)
60 		return NULL;
61 
62 	block->addr = entry->addr;
63 	block->size = size;
64 	list_add(&block->list, &vm->used);
65 	entry->addr += size;
66 	entry->size -= size;
67 	vm->size -= size;
68 
69 	return block;
70 }
71 
72 static void put_vm_block(struct ct_vm *vm, struct ct_vm_block *block)
73 {
74 	struct ct_vm_block *entry, *pre_ent;
75 	struct list_head *pos, *pre;
76 
77 	block->size = CT_PAGE_ALIGN(block->size);
78 
79 	guard(mutex)(&vm->lock);
80 	list_del(&block->list);
81 	vm->size += block->size;
82 
83 	list_for_each(pos, &vm->unused) {
84 		entry = list_entry(pos, struct ct_vm_block, list);
85 		if (entry->addr >= (block->addr + block->size))
86 			break; /* found a position */
87 	}
88 	if (pos == &vm->unused) {
89 		list_add_tail(&block->list, &vm->unused);
90 		entry = block;
91 	} else {
92 		if ((block->addr + block->size) == entry->addr) {
93 			entry->addr = block->addr;
94 			entry->size += block->size;
95 			kfree(block);
96 		} else {
97 			__list_add(&block->list, pos->prev, pos);
98 			entry = block;
99 		}
100 	}
101 
102 	pos = &entry->list;
103 	pre = pos->prev;
104 	while (pre != &vm->unused) {
105 		entry = list_entry(pos, struct ct_vm_block, list);
106 		pre_ent = list_entry(pre, struct ct_vm_block, list);
107 		if ((pre_ent->addr + pre_ent->size) > entry->addr)
108 			break;
109 
110 		pre_ent->size += entry->size;
111 		list_del(pos);
112 		kfree(entry);
113 		pos = pre;
114 		pre = pos->prev;
115 	}
116 }
117 
118 /* Map host addr (kmalloced/vmalloced) to device logical addr. */
119 static struct ct_vm_block *
120 ct_vm_map(struct ct_vm *vm, struct snd_pcm_substream *substream, int size)
121 {
122 	struct ct_vm_block *block;
123 	unsigned int pte_start;
124 	unsigned i, pages;
125 	unsigned long *ptp;
126 	struct ct_atc *atc = snd_pcm_substream_chip(substream);
127 
128 	block = get_vm_block(vm, size, atc);
129 	if (block == NULL) {
130 		dev_err(atc->card->dev,
131 			"No virtual memory block that is big enough to allocate!\n");
132 		return NULL;
133 	}
134 
135 	ptp = (unsigned long *)vm->ptp[0].area;
136 	pte_start = (block->addr >> CT_PAGE_SHIFT);
137 	pages = block->size >> CT_PAGE_SHIFT;
138 	for (i = 0; i < pages; i++) {
139 		unsigned long addr;
140 		addr = snd_pcm_sgbuf_get_addr(substream, i << CT_PAGE_SHIFT);
141 		ptp[pte_start + i] = addr;
142 	}
143 
144 	block->size = size;
145 	return block;
146 }
147 
148 static void ct_vm_unmap(struct ct_vm *vm, struct ct_vm_block *block)
149 {
150 	/* do unmapping */
151 	put_vm_block(vm, block);
152 }
153 
154 /* *
155  * return the host physical addr of the @index-th device
156  * page table page on success, or ~0UL on failure.
157  * The first returned ~0UL indicates the termination.
158  * */
159 static dma_addr_t
160 ct_get_ptp_phys(struct ct_vm *vm, int index)
161 {
162 	return (index >= CT_PTP_NUM) ? ~0UL : vm->ptp[index].addr;
163 }
164 
165 int ct_vm_create(struct ct_vm **rvm, struct pci_dev *pci)
166 {
167 	struct ct_vm *vm;
168 	struct ct_vm_block *block;
169 	int i, err = 0;
170 
171 	*rvm = NULL;
172 
173 	vm = kzalloc(sizeof(*vm), GFP_KERNEL);
174 	if (!vm)
175 		return -ENOMEM;
176 
177 	mutex_init(&vm->lock);
178 
179 	/* Allocate page table pages */
180 	for (i = 0; i < CT_PTP_NUM; i++) {
181 		err = snd_dma_alloc_pages(SNDRV_DMA_TYPE_DEV,
182 					  &pci->dev,
183 					  PAGE_SIZE, &vm->ptp[i]);
184 		if (err < 0)
185 			break;
186 	}
187 	if (err < 0) {
188 		/* no page table pages are allocated */
189 		ct_vm_destroy(vm);
190 		return -ENOMEM;
191 	}
192 	vm->size = CT_ADDRS_PER_PAGE * i;
193 	vm->map = ct_vm_map;
194 	vm->unmap = ct_vm_unmap;
195 	vm->get_ptp_phys = ct_get_ptp_phys;
196 	INIT_LIST_HEAD(&vm->unused);
197 	INIT_LIST_HEAD(&vm->used);
198 	block = kzalloc(sizeof(*block), GFP_KERNEL);
199 	if (NULL != block) {
200 		block->addr = 0;
201 		block->size = vm->size;
202 		list_add(&block->list, &vm->unused);
203 	}
204 
205 	*rvm = vm;
206 	return 0;
207 }
208 
209 /* The caller must ensure no mapping pages are being used
210  * by hardware before calling this function */
211 void ct_vm_destroy(struct ct_vm *vm)
212 {
213 	int i;
214 	struct list_head *pos;
215 	struct ct_vm_block *entry;
216 
217 	/* free used and unused list nodes */
218 	while (!list_empty(&vm->used)) {
219 		pos = vm->used.next;
220 		list_del(pos);
221 		entry = list_entry(pos, struct ct_vm_block, list);
222 		kfree(entry);
223 	}
224 	while (!list_empty(&vm->unused)) {
225 		pos = vm->unused.next;
226 		list_del(pos);
227 		entry = list_entry(pos, struct ct_vm_block, list);
228 		kfree(entry);
229 	}
230 
231 	/* free allocated page table pages */
232 	for (i = 0; i < CT_PTP_NUM; i++)
233 		snd_dma_free_pages(&vm->ptp[i]);
234 
235 	vm->size = 0;
236 
237 	kfree(vm);
238 }
239