2 * Copyright (c) 2015-2016 MediaTek Inc.
3 * Author: Honghui Zhang <honghui.zhang@mediatek.com>
5 * Based on driver/iommu/mtk_iommu.c
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License version 2 as
9 * published by the Free Software Foundation.
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
16 #include <linux/bootmem.h>
17 #include <linux/bug.h>
18 #include <linux/clk.h>
19 #include <linux/component.h>
20 #include <linux/device.h>
21 #include <linux/dma-mapping.h>
22 #include <linux/dma-iommu.h>
23 #include <linux/err.h>
24 #include <linux/interrupt.h>
26 #include <linux/iommu.h>
27 #include <linux/iopoll.h>
28 #include <linux/kmemleak.h>
29 #include <linux/list.h>
30 #include <linux/of_address.h>
31 #include <linux/of_iommu.h>
32 #include <linux/of_irq.h>
33 #include <linux/of_platform.h>
34 #include <linux/platform_device.h>
35 #include <linux/slab.h>
36 #include <linux/spinlock.h>
37 #include <asm/barrier.h>
38 #include <asm/dma-iommu.h>
39 #include <linux/module.h>
40 #include <dt-bindings/memory/mt2701-larb-port.h>
41 #include <soc/mediatek/smi.h>
42 #include "mtk_iommu.h"
44 #define REG_MMU_PT_BASE_ADDR 0x000
46 #define F_ALL_INVLD 0x2
47 #define F_MMU_INV_RANGE 0x1
48 #define F_INVLD_EN0 BIT(0)
49 #define F_INVLD_EN1 BIT(1)
51 #define F_MMU_FAULT_VA_MSK 0xfffff000
52 #define MTK_PROTECT_PA_ALIGN 128
54 #define REG_MMU_CTRL_REG 0x210
55 #define F_MMU_CTRL_COHERENT_EN BIT(8)
56 #define REG_MMU_IVRP_PADDR 0x214
57 #define REG_MMU_INT_CONTROL 0x220
58 #define F_INT_TRANSLATION_FAULT BIT(0)
59 #define F_INT_MAIN_MULTI_HIT_FAULT BIT(1)
60 #define F_INT_INVALID_PA_FAULT BIT(2)
61 #define F_INT_ENTRY_REPLACEMENT_FAULT BIT(3)
62 #define F_INT_TABLE_WALK_FAULT BIT(4)
63 #define F_INT_TLB_MISS_FAULT BIT(5)
64 #define F_INT_PFH_DMA_FIFO_OVERFLOW BIT(6)
65 #define F_INT_MISS_DMA_FIFO_OVERFLOW BIT(7)
67 #define F_MMU_TF_PROTECT_SEL(prot) (((prot) & 0x3) << 5)
68 #define F_INT_CLR_BIT BIT(12)
70 #define REG_MMU_FAULT_ST 0x224
71 #define REG_MMU_FAULT_VA 0x228
72 #define REG_MMU_INVLD_PA 0x22C
73 #define REG_MMU_INT_ID 0x388
74 #define REG_MMU_INVALIDATE 0x5c0
75 #define REG_MMU_INVLD_START_A 0x5c4
76 #define REG_MMU_INVLD_END_A 0x5c8
78 #define REG_MMU_INV_SEL 0x5d8
79 #define REG_MMU_STANDARD_AXI_MODE 0x5e8
81 #define REG_MMU_DCM 0x5f0
82 #define F_MMU_DCM_ON BIT(1)
83 #define REG_MMU_CPE_DONE 0x60c
84 #define F_DESC_VALID 0x2
85 #define F_DESC_NONSEC BIT(3)
86 #define MT2701_M4U_TF_LARB(TF) (6 - (((TF) >> 13) & 0x7))
87 #define MT2701_M4U_TF_PORT(TF) (((TF) >> 8) & 0xF)
88 /* MTK generation one iommu HW only support 4K size mapping */
89 #define MT2701_IOMMU_PAGE_SHIFT 12
90 #define MT2701_IOMMU_PAGE_SIZE (1UL << MT2701_IOMMU_PAGE_SHIFT)
93 * MTK m4u support 4GB iova address space, and only support 4K page
94 * mapping. So the pagetable size should be exactly as 4M.
96 #define M2701_IOMMU_PGT_SIZE SZ_4M
98 struct mtk_iommu_domain {
99 spinlock_t pgtlock; /* lock for page table */
100 struct iommu_domain domain;
103 struct mtk_iommu_data *data;
106 static struct mtk_iommu_domain *to_mtk_domain(struct iommu_domain *dom)
108 return container_of(dom, struct mtk_iommu_domain, domain);
111 static const int mt2701_m4u_in_larb[] = {
112 LARB0_PORT_OFFSET, LARB1_PORT_OFFSET,
113 LARB2_PORT_OFFSET, LARB3_PORT_OFFSET
116 static inline int mt2701_m4u_to_larb(int id)
120 for (i = ARRAY_SIZE(mt2701_m4u_in_larb) - 1; i >= 0; i--)
121 if ((id) >= mt2701_m4u_in_larb[i])
127 static inline int mt2701_m4u_to_port(int id)
129 int larb = mt2701_m4u_to_larb(id);
131 return id - mt2701_m4u_in_larb[larb];
134 static void mtk_iommu_tlb_flush_all(struct mtk_iommu_data *data)
136 writel_relaxed(F_INVLD_EN1 | F_INVLD_EN0,
137 data->base + REG_MMU_INV_SEL);
138 writel_relaxed(F_ALL_INVLD, data->base + REG_MMU_INVALIDATE);
139 wmb(); /* Make sure the tlb flush all done */
142 static void mtk_iommu_tlb_flush_range(struct mtk_iommu_data *data,
143 unsigned long iova, size_t size)
148 writel_relaxed(F_INVLD_EN1 | F_INVLD_EN0,
149 data->base + REG_MMU_INV_SEL);
150 writel_relaxed(iova & F_MMU_FAULT_VA_MSK,
151 data->base + REG_MMU_INVLD_START_A);
152 writel_relaxed((iova + size - 1) & F_MMU_FAULT_VA_MSK,
153 data->base + REG_MMU_INVLD_END_A);
154 writel_relaxed(F_MMU_INV_RANGE, data->base + REG_MMU_INVALIDATE);
156 ret = readl_poll_timeout_atomic(data->base + REG_MMU_CPE_DONE,
157 tmp, tmp != 0, 10, 100000);
160 "Partial TLB flush timed out, falling back to full flush\n");
161 mtk_iommu_tlb_flush_all(data);
163 /* Clear the CPE status */
164 writel_relaxed(0, data->base + REG_MMU_CPE_DONE);
167 static irqreturn_t mtk_iommu_isr(int irq, void *dev_id)
169 struct mtk_iommu_data *data = dev_id;
170 struct mtk_iommu_domain *dom = data->m4u_dom;
171 u32 int_state, regval, fault_iova, fault_pa;
172 unsigned int fault_larb, fault_port;
174 /* Read error information from registers */
175 int_state = readl_relaxed(data->base + REG_MMU_FAULT_ST);
176 fault_iova = readl_relaxed(data->base + REG_MMU_FAULT_VA);
178 fault_iova &= F_MMU_FAULT_VA_MSK;
179 fault_pa = readl_relaxed(data->base + REG_MMU_INVLD_PA);
180 regval = readl_relaxed(data->base + REG_MMU_INT_ID);
181 fault_larb = MT2701_M4U_TF_LARB(regval);
182 fault_port = MT2701_M4U_TF_PORT(regval);
185 * MTK v1 iommu HW could not determine whether the fault is read or
186 * write fault, report as read fault.
188 if (report_iommu_fault(&dom->domain, data->dev, fault_iova,
190 dev_err_ratelimited(data->dev,
191 "fault type=0x%x iova=0x%x pa=0x%x larb=%d port=%d\n",
192 int_state, fault_iova, fault_pa,
193 fault_larb, fault_port);
195 /* Interrupt clear */
196 regval = readl_relaxed(data->base + REG_MMU_INT_CONTROL);
197 regval |= F_INT_CLR_BIT;
198 writel_relaxed(regval, data->base + REG_MMU_INT_CONTROL);
200 mtk_iommu_tlb_flush_all(data);
205 static void mtk_iommu_config(struct mtk_iommu_data *data,
206 struct device *dev, bool enable)
208 struct mtk_smi_larb_iommu *larb_mmu;
209 unsigned int larbid, portid;
210 struct iommu_fwspec *fwspec = dev->iommu_fwspec;
213 for (i = 0; i < fwspec->num_ids; ++i) {
214 larbid = mt2701_m4u_to_larb(fwspec->ids[i]);
215 portid = mt2701_m4u_to_port(fwspec->ids[i]);
216 larb_mmu = &data->smi_imu.larb_imu[larbid];
218 dev_dbg(dev, "%s iommu port: %d\n",
219 enable ? "enable" : "disable", portid);
222 larb_mmu->mmu |= MTK_SMI_MMU_EN(portid);
224 larb_mmu->mmu &= ~MTK_SMI_MMU_EN(portid);
228 static int mtk_iommu_domain_finalise(struct mtk_iommu_data *data)
230 struct mtk_iommu_domain *dom = data->m4u_dom;
232 spin_lock_init(&dom->pgtlock);
234 dom->pgt_va = dma_zalloc_coherent(data->dev,
235 M2701_IOMMU_PGT_SIZE,
236 &dom->pgt_pa, GFP_KERNEL);
240 writel(dom->pgt_pa, data->base + REG_MMU_PT_BASE_ADDR);
247 static struct iommu_domain *mtk_iommu_domain_alloc(unsigned type)
249 struct mtk_iommu_domain *dom;
251 if (type != IOMMU_DOMAIN_UNMANAGED)
254 dom = kzalloc(sizeof(*dom), GFP_KERNEL);
261 static void mtk_iommu_domain_free(struct iommu_domain *domain)
263 struct mtk_iommu_domain *dom = to_mtk_domain(domain);
264 struct mtk_iommu_data *data = dom->data;
266 dma_free_coherent(data->dev, M2701_IOMMU_PGT_SIZE,
267 dom->pgt_va, dom->pgt_pa);
268 kfree(to_mtk_domain(domain));
271 static int mtk_iommu_attach_device(struct iommu_domain *domain,
274 struct mtk_iommu_domain *dom = to_mtk_domain(domain);
275 struct mtk_iommu_data *data = dev->iommu_fwspec->iommu_priv;
281 if (!data->m4u_dom) {
283 ret = mtk_iommu_domain_finalise(data);
285 data->m4u_dom = NULL;
290 mtk_iommu_config(data, dev, true);
294 static void mtk_iommu_detach_device(struct iommu_domain *domain,
297 struct mtk_iommu_data *data = dev->iommu_fwspec->iommu_priv;
302 mtk_iommu_config(data, dev, false);
305 static int mtk_iommu_map(struct iommu_domain *domain, unsigned long iova,
306 phys_addr_t paddr, size_t size, int prot)
308 struct mtk_iommu_domain *dom = to_mtk_domain(domain);
309 unsigned int page_num = size >> MT2701_IOMMU_PAGE_SHIFT;
312 u32 *pgt_base_iova = dom->pgt_va + (iova >> MT2701_IOMMU_PAGE_SHIFT);
313 u32 pabase = (u32)paddr;
316 spin_lock_irqsave(&dom->pgtlock, flags);
317 for (i = 0; i < page_num; i++) {
318 if (pgt_base_iova[i]) {
319 memset(pgt_base_iova, 0, i * sizeof(u32));
322 pgt_base_iova[i] = pabase | F_DESC_VALID | F_DESC_NONSEC;
323 pabase += MT2701_IOMMU_PAGE_SIZE;
324 map_size += MT2701_IOMMU_PAGE_SIZE;
327 spin_unlock_irqrestore(&dom->pgtlock, flags);
329 mtk_iommu_tlb_flush_range(dom->data, iova, size);
331 return map_size == size ? 0 : -EEXIST;
334 static size_t mtk_iommu_unmap(struct iommu_domain *domain,
335 unsigned long iova, size_t size)
337 struct mtk_iommu_domain *dom = to_mtk_domain(domain);
339 u32 *pgt_base_iova = dom->pgt_va + (iova >> MT2701_IOMMU_PAGE_SHIFT);
340 unsigned int page_num = size >> MT2701_IOMMU_PAGE_SHIFT;
342 spin_lock_irqsave(&dom->pgtlock, flags);
343 memset(pgt_base_iova, 0, page_num * sizeof(u32));
344 spin_unlock_irqrestore(&dom->pgtlock, flags);
346 mtk_iommu_tlb_flush_range(dom->data, iova, size);
351 static phys_addr_t mtk_iommu_iova_to_phys(struct iommu_domain *domain,
354 struct mtk_iommu_domain *dom = to_mtk_domain(domain);
358 spin_lock_irqsave(&dom->pgtlock, flags);
359 pa = *(dom->pgt_va + (iova >> MT2701_IOMMU_PAGE_SHIFT));
360 pa = pa & (~(MT2701_IOMMU_PAGE_SIZE - 1));
361 spin_unlock_irqrestore(&dom->pgtlock, flags);
366 static struct iommu_ops mtk_iommu_ops;
369 * MTK generation one iommu HW only support one iommu domain, and all the client
370 * sharing the same iova address space.
372 static int mtk_iommu_create_mapping(struct device *dev,
373 struct of_phandle_args *args)
375 struct mtk_iommu_data *data;
376 struct platform_device *m4updev;
377 struct dma_iommu_mapping *mtk_mapping;
378 struct device *m4udev;
381 if (args->args_count != 1) {
382 dev_err(dev, "invalid #iommu-cells(%d) property for IOMMU\n",
387 if (!dev->iommu_fwspec) {
388 ret = iommu_fwspec_init(dev, &args->np->fwnode, &mtk_iommu_ops);
391 } else if (dev->iommu_fwspec->ops != &mtk_iommu_ops) {
395 if (!dev->iommu_fwspec->iommu_priv) {
396 /* Get the m4u device */
397 m4updev = of_find_device_by_node(args->np);
398 if (WARN_ON(!m4updev))
401 dev->iommu_fwspec->iommu_priv = platform_get_drvdata(m4updev);
404 ret = iommu_fwspec_add_ids(dev, args->args, 1);
408 data = dev->iommu_fwspec->iommu_priv;
410 mtk_mapping = m4udev->archdata.iommu;
412 /* MTK iommu support 4GB iova address space. */
413 mtk_mapping = arm_iommu_create_mapping(&platform_bus_type,
415 if (IS_ERR(mtk_mapping))
416 return PTR_ERR(mtk_mapping);
418 m4udev->archdata.iommu = mtk_mapping;
421 ret = arm_iommu_attach_device(dev, mtk_mapping);
423 goto err_release_mapping;
428 arm_iommu_release_mapping(mtk_mapping);
429 m4udev->archdata.iommu = NULL;
433 static int mtk_iommu_add_device(struct device *dev)
435 struct of_phandle_args iommu_spec;
436 struct of_phandle_iterator it;
437 struct mtk_iommu_data *data;
438 struct iommu_group *group;
441 of_for_each_phandle(&it, err, dev->of_node, "iommus",
443 int count = of_phandle_iterator_args(&it, iommu_spec.args,
445 iommu_spec.np = of_node_get(it.node);
446 iommu_spec.args_count = count;
448 mtk_iommu_create_mapping(dev, &iommu_spec);
449 of_node_put(iommu_spec.np);
452 if (!dev->iommu_fwspec || dev->iommu_fwspec->ops != &mtk_iommu_ops)
453 return -ENODEV; /* Not a iommu client device */
455 data = dev->iommu_fwspec->iommu_priv;
456 iommu_device_link(&data->iommu, dev);
458 group = iommu_group_get_for_dev(dev);
460 return PTR_ERR(group);
462 iommu_group_put(group);
466 static void mtk_iommu_remove_device(struct device *dev)
468 struct mtk_iommu_data *data;
470 if (!dev->iommu_fwspec || dev->iommu_fwspec->ops != &mtk_iommu_ops)
473 data = dev->iommu_fwspec->iommu_priv;
474 iommu_device_unlink(&data->iommu, dev);
476 iommu_group_remove_device(dev);
477 iommu_fwspec_free(dev);
480 static struct iommu_group *mtk_iommu_device_group(struct device *dev)
482 struct mtk_iommu_data *data = dev->iommu_fwspec->iommu_priv;
485 return ERR_PTR(-ENODEV);
487 /* All the client devices are in the same m4u iommu-group */
488 if (!data->m4u_group) {
489 data->m4u_group = iommu_group_alloc();
490 if (IS_ERR(data->m4u_group))
491 dev_err(dev, "Failed to allocate M4U IOMMU group\n");
493 iommu_group_ref_get(data->m4u_group);
495 return data->m4u_group;
498 static int mtk_iommu_hw_init(const struct mtk_iommu_data *data)
503 ret = clk_prepare_enable(data->bclk);
505 dev_err(data->dev, "Failed to enable iommu bclk(%d)\n", ret);
509 regval = F_MMU_CTRL_COHERENT_EN | F_MMU_TF_PROTECT_SEL(2);
510 writel_relaxed(regval, data->base + REG_MMU_CTRL_REG);
512 regval = F_INT_TRANSLATION_FAULT |
513 F_INT_MAIN_MULTI_HIT_FAULT |
514 F_INT_INVALID_PA_FAULT |
515 F_INT_ENTRY_REPLACEMENT_FAULT |
516 F_INT_TABLE_WALK_FAULT |
517 F_INT_TLB_MISS_FAULT |
518 F_INT_PFH_DMA_FIFO_OVERFLOW |
519 F_INT_MISS_DMA_FIFO_OVERFLOW;
520 writel_relaxed(regval, data->base + REG_MMU_INT_CONTROL);
522 /* protect memory,hw will write here while translation fault */
523 writel_relaxed(data->protect_base,
524 data->base + REG_MMU_IVRP_PADDR);
526 writel_relaxed(F_MMU_DCM_ON, data->base + REG_MMU_DCM);
528 if (devm_request_irq(data->dev, data->irq, mtk_iommu_isr, 0,
529 dev_name(data->dev), (void *)data)) {
530 writel_relaxed(0, data->base + REG_MMU_PT_BASE_ADDR);
531 clk_disable_unprepare(data->bclk);
532 dev_err(data->dev, "Failed @ IRQ-%d Request\n", data->irq);
539 static struct iommu_ops mtk_iommu_ops = {
540 .domain_alloc = mtk_iommu_domain_alloc,
541 .domain_free = mtk_iommu_domain_free,
542 .attach_dev = mtk_iommu_attach_device,
543 .detach_dev = mtk_iommu_detach_device,
544 .map = mtk_iommu_map,
545 .unmap = mtk_iommu_unmap,
546 .map_sg = default_iommu_map_sg,
547 .iova_to_phys = mtk_iommu_iova_to_phys,
548 .add_device = mtk_iommu_add_device,
549 .remove_device = mtk_iommu_remove_device,
550 .device_group = mtk_iommu_device_group,
551 .pgsize_bitmap = ~0UL << MT2701_IOMMU_PAGE_SHIFT,
554 static const struct of_device_id mtk_iommu_of_ids[] = {
555 { .compatible = "mediatek,mt2701-m4u", },
559 static const struct component_master_ops mtk_iommu_com_ops = {
560 .bind = mtk_iommu_bind,
561 .unbind = mtk_iommu_unbind,
564 static int mtk_iommu_probe(struct platform_device *pdev)
566 struct mtk_iommu_data *data;
567 struct device *dev = &pdev->dev;
568 struct resource *res;
569 struct component_match *match = NULL;
570 struct of_phandle_args larb_spec;
571 struct of_phandle_iterator it;
573 int larb_nr, ret, err;
575 data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
581 /* Protect memory. HW will access here while translation fault.*/
582 protect = devm_kzalloc(dev, MTK_PROTECT_PA_ALIGN * 2,
583 GFP_KERNEL | GFP_DMA);
586 data->protect_base = ALIGN(virt_to_phys(protect), MTK_PROTECT_PA_ALIGN);
588 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
589 data->base = devm_ioremap_resource(dev, res);
590 if (IS_ERR(data->base))
591 return PTR_ERR(data->base);
593 data->irq = platform_get_irq(pdev, 0);
597 data->bclk = devm_clk_get(dev, "bclk");
598 if (IS_ERR(data->bclk))
599 return PTR_ERR(data->bclk);
602 of_for_each_phandle(&it, err, dev->of_node,
603 "mediatek,larbs", NULL, 0) {
604 struct platform_device *plarbdev;
605 int count = of_phandle_iterator_args(&it, larb_spec.args,
611 larb_spec.np = of_node_get(it.node);
612 if (!of_device_is_available(larb_spec.np))
615 plarbdev = of_find_device_by_node(larb_spec.np);
617 plarbdev = of_platform_device_create(
619 platform_bus_type.dev_root);
621 of_node_put(larb_spec.np);
622 return -EPROBE_DEFER;
626 data->smi_imu.larb_imu[larb_nr].dev = &plarbdev->dev;
627 component_match_add_release(dev, &match, release_of,
628 compare_of, larb_spec.np);
632 data->smi_imu.larb_nr = larb_nr;
634 platform_set_drvdata(pdev, data);
636 ret = mtk_iommu_hw_init(data);
640 ret = iommu_device_sysfs_add(&data->iommu, &pdev->dev, NULL,
641 dev_name(&pdev->dev));
645 iommu_device_set_ops(&data->iommu, &mtk_iommu_ops);
647 ret = iommu_device_register(&data->iommu);
651 if (!iommu_present(&platform_bus_type))
652 bus_set_iommu(&platform_bus_type, &mtk_iommu_ops);
654 return component_master_add_with_match(dev, &mtk_iommu_com_ops, match);
657 static int mtk_iommu_remove(struct platform_device *pdev)
659 struct mtk_iommu_data *data = platform_get_drvdata(pdev);
661 iommu_device_sysfs_remove(&data->iommu);
662 iommu_device_unregister(&data->iommu);
664 if (iommu_present(&platform_bus_type))
665 bus_set_iommu(&platform_bus_type, NULL);
667 clk_disable_unprepare(data->bclk);
668 devm_free_irq(&pdev->dev, data->irq, data);
669 component_master_del(&pdev->dev, &mtk_iommu_com_ops);
673 static int __maybe_unused mtk_iommu_suspend(struct device *dev)
675 struct mtk_iommu_data *data = dev_get_drvdata(dev);
676 struct mtk_iommu_suspend_reg *reg = &data->reg;
677 void __iomem *base = data->base;
679 reg->standard_axi_mode = readl_relaxed(base +
680 REG_MMU_STANDARD_AXI_MODE);
681 reg->dcm_dis = readl_relaxed(base + REG_MMU_DCM);
682 reg->ctrl_reg = readl_relaxed(base + REG_MMU_CTRL_REG);
683 reg->int_control0 = readl_relaxed(base + REG_MMU_INT_CONTROL);
687 static int __maybe_unused mtk_iommu_resume(struct device *dev)
689 struct mtk_iommu_data *data = dev_get_drvdata(dev);
690 struct mtk_iommu_suspend_reg *reg = &data->reg;
691 void __iomem *base = data->base;
693 writel_relaxed(data->m4u_dom->pgt_pa, base + REG_MMU_PT_BASE_ADDR);
694 writel_relaxed(reg->standard_axi_mode,
695 base + REG_MMU_STANDARD_AXI_MODE);
696 writel_relaxed(reg->dcm_dis, base + REG_MMU_DCM);
697 writel_relaxed(reg->ctrl_reg, base + REG_MMU_CTRL_REG);
698 writel_relaxed(reg->int_control0, base + REG_MMU_INT_CONTROL);
699 writel_relaxed(data->protect_base, base + REG_MMU_IVRP_PADDR);
703 static const struct dev_pm_ops mtk_iommu_pm_ops = {
704 SET_SYSTEM_SLEEP_PM_OPS(mtk_iommu_suspend, mtk_iommu_resume)
707 static struct platform_driver mtk_iommu_driver = {
708 .probe = mtk_iommu_probe,
709 .remove = mtk_iommu_remove,
712 .of_match_table = mtk_iommu_of_ids,
713 .pm = &mtk_iommu_pm_ops,
717 static int __init m4u_init(void)
719 return platform_driver_register(&mtk_iommu_driver);
722 static void __exit m4u_exit(void)
724 return platform_driver_unregister(&mtk_iommu_driver);
727 subsys_initcall(m4u_init);
728 module_exit(m4u_exit);
730 MODULE_DESCRIPTION("IOMMU API for MTK architected m4u v1 implementations");
731 MODULE_AUTHOR("Honghui Zhang <honghui.zhang@mediatek.com>");
732 MODULE_LICENSE("GPL v2");