1 /*
2  * This program is free software; you can redistribute it and/or modify
3  * it under the terms of the GNU General Public License version 2 as
4  * published by the Free Software Foundation.
5  */
6 
7 #include <linux/compiler.h>
8 #include <linux/delay.h>
9 #include <linux/device.h>
10 #include <linux/dma-iommu.h>
11 #include <linux/dma-mapping.h>
12 #include <linux/errno.h>
13 #include <linux/interrupt.h>
14 #include <linux/io.h>
15 #include <linux/iommu.h>
16 #include <linux/jiffies.h>
17 #include <linux/list.h>
18 #include <linux/mm.h>
19 #include <linux/module.h>
20 #include <linux/of.h>
21 #include <linux/of_platform.h>
22 #include <linux/platform_device.h>
23 #include <linux/slab.h>
24 #include <linux/spinlock.h>
25 
26 /** MMU register offsets */
27 #define RK_MMU_DTE_ADDR		0x00	/* Directory table address */
28 #define RK_MMU_STATUS		0x04
29 #define RK_MMU_COMMAND		0x08
30 #define RK_MMU_PAGE_FAULT_ADDR	0x0C	/* IOVA of last page fault */
31 #define RK_MMU_ZAP_ONE_LINE	0x10	/* Shootdown one IOTLB entry */
32 #define RK_MMU_INT_RAWSTAT	0x14	/* IRQ status ignoring mask */
33 #define RK_MMU_INT_CLEAR	0x18	/* Acknowledge and re-arm irq */
34 #define RK_MMU_INT_MASK		0x1C	/* IRQ enable */
35 #define RK_MMU_INT_STATUS	0x20	/* IRQ status after masking */
36 #define RK_MMU_AUTO_GATING	0x24
37 
38 #define DTE_ADDR_DUMMY		0xCAFEBABE
39 #define FORCE_RESET_TIMEOUT	100	/* ms */
40 
41 /* RK_MMU_STATUS fields */
42 #define RK_MMU_STATUS_PAGING_ENABLED       BIT(0)
43 #define RK_MMU_STATUS_PAGE_FAULT_ACTIVE    BIT(1)
44 #define RK_MMU_STATUS_STALL_ACTIVE         BIT(2)
45 #define RK_MMU_STATUS_IDLE                 BIT(3)
46 #define RK_MMU_STATUS_REPLAY_BUFFER_EMPTY  BIT(4)
47 #define RK_MMU_STATUS_PAGE_FAULT_IS_WRITE  BIT(5)
48 #define RK_MMU_STATUS_STALL_NOT_ACTIVE     BIT(31)
49 
50 /* RK_MMU_COMMAND command values */
51 #define RK_MMU_CMD_ENABLE_PAGING    0  /* Enable memory translation */
52 #define RK_MMU_CMD_DISABLE_PAGING   1  /* Disable memory translation */
53 #define RK_MMU_CMD_ENABLE_STALL     2  /* Stall paging to allow other cmds */
54 #define RK_MMU_CMD_DISABLE_STALL    3  /* Stop stall re-enables paging */
55 #define RK_MMU_CMD_ZAP_CACHE        4  /* Shoot down entire IOTLB */
56 #define RK_MMU_CMD_PAGE_FAULT_DONE  5  /* Clear page fault */
57 #define RK_MMU_CMD_FORCE_RESET      6  /* Reset all registers */
58 
59 /* RK_MMU_INT_* register fields */
60 #define RK_MMU_IRQ_PAGE_FAULT    0x01  /* page fault */
61 #define RK_MMU_IRQ_BUS_ERROR     0x02  /* bus read error */
62 #define RK_MMU_IRQ_MASK          (RK_MMU_IRQ_PAGE_FAULT | RK_MMU_IRQ_BUS_ERROR)
63 
64 #define NUM_DT_ENTRIES 1024
65 #define NUM_PT_ENTRIES 1024
66 
67 #define SPAGE_ORDER 12
68 #define SPAGE_SIZE (1 << SPAGE_ORDER)
69 
70  /*
71   * Support mapping any size that fits in one page table:
72   *   4 KiB to 4 MiB
73   */
74 #define RK_IOMMU_PGSIZE_BITMAP 0x007ff000
75 
76 #define IOMMU_REG_POLL_COUNT_FAST 1000
77 
78 struct rk_iommu_domain {
79 	struct list_head iommus;
80 	struct platform_device *pdev;
81 	u32 *dt; /* page directory table */
82 	dma_addr_t dt_dma;
83 	spinlock_t iommus_lock; /* lock for iommus list */
84 	spinlock_t dt_lock; /* lock for modifying page directory table */
85 
86 	struct iommu_domain domain;
87 };
88 
89 struct rk_iommu {
90 	struct device *dev;
91 	void __iomem **bases;
92 	int num_mmu;
93 	int *irq;
94 	int num_irq;
95 	bool reset_disabled;
96 	struct iommu_device iommu;
97 	struct list_head node; /* entry in rk_iommu_domain.iommus */
98 	struct iommu_domain *domain; /* domain to which iommu is attached */
99 };
100 
101 static inline void rk_table_flush(struct rk_iommu_domain *dom, dma_addr_t dma,
102 				  unsigned int count)
103 {
104 	size_t size = count * sizeof(u32); /* count of u32 entry */
105 
106 	dma_sync_single_for_device(&dom->pdev->dev, dma, size, DMA_TO_DEVICE);
107 }
108 
109 static struct rk_iommu_domain *to_rk_domain(struct iommu_domain *dom)
110 {
111 	return container_of(dom, struct rk_iommu_domain, domain);
112 }
113 
114 /**
115  * Inspired by _wait_for in intel_drv.h
116  * This is NOT safe for use in interrupt context.
117  *
118  * Note that it's important that we check the condition again after having
119  * timed out, since the timeout could be due to preemption or similar and
120  * we've never had a chance to check the condition before the timeout.
121  */
122 #define rk_wait_for(COND, MS) ({ \
123 	unsigned long timeout__ = jiffies + msecs_to_jiffies(MS) + 1;	\
124 	int ret__ = 0;							\
125 	while (!(COND)) {						\
126 		if (time_after(jiffies, timeout__)) {			\
127 			ret__ = (COND) ? 0 : -ETIMEDOUT;		\
128 			break;						\
129 		}							\
130 		usleep_range(50, 100);					\
131 	}								\
132 	ret__;								\
133 })
134 
135 /*
136  * The Rockchip rk3288 iommu uses a 2-level page table.
137  * The first level is the "Directory Table" (DT).
138  * The DT consists of 1024 4-byte Directory Table Entries (DTEs), each pointing
139  * to a "Page Table".
140  * The second level is the 1024 Page Tables (PT).
141  * Each PT consists of 1024 4-byte Page Table Entries (PTEs), each pointing to
142  * a 4 KB page of physical memory.
143  *
144  * The DT and each PT fits in a single 4 KB page (4-bytes * 1024 entries).
145  * Each iommu device has a MMU_DTE_ADDR register that contains the physical
146  * address of the start of the DT page.
147  *
148  * The structure of the page table is as follows:
149  *
150  *                   DT
151  * MMU_DTE_ADDR -> +-----+
152  *                 |     |
153  *                 +-----+     PT
154  *                 | DTE | -> +-----+
155  *                 +-----+    |     |     Memory
156  *                 |     |    +-----+     Page
157  *                 |     |    | PTE | -> +-----+
158  *                 +-----+    +-----+    |     |
159  *                            |     |    |     |
160  *                            |     |    |     |
161  *                            +-----+    |     |
162  *                                       |     |
163  *                                       |     |
164  *                                       +-----+
165  */
166 
167 /*
168  * Each DTE has a PT address and a valid bit:
169  * +---------------------+-----------+-+
170  * | PT address          | Reserved  |V|
171  * +---------------------+-----------+-+
172  *  31:12 - PT address (PTs always starts on a 4 KB boundary)
173  *  11: 1 - Reserved
174  *      0 - 1 if PT @ PT address is valid
175  */
176 #define RK_DTE_PT_ADDRESS_MASK    0xfffff000
177 #define RK_DTE_PT_VALID           BIT(0)
178 
179 static inline phys_addr_t rk_dte_pt_address(u32 dte)
180 {
181 	return (phys_addr_t)dte & RK_DTE_PT_ADDRESS_MASK;
182 }
183 
184 static inline bool rk_dte_is_pt_valid(u32 dte)
185 {
186 	return dte & RK_DTE_PT_VALID;
187 }
188 
189 static inline u32 rk_mk_dte(dma_addr_t pt_dma)
190 {
191 	return (pt_dma & RK_DTE_PT_ADDRESS_MASK) | RK_DTE_PT_VALID;
192 }
193 
194 /*
195  * Each PTE has a Page address, some flags and a valid bit:
196  * +---------------------+---+-------+-+
197  * | Page address        |Rsv| Flags |V|
198  * +---------------------+---+-------+-+
199  *  31:12 - Page address (Pages always start on a 4 KB boundary)
200  *  11: 9 - Reserved
201  *   8: 1 - Flags
202  *      8 - Read allocate - allocate cache space on read misses
203  *      7 - Read cache - enable cache & prefetch of data
204  *      6 - Write buffer - enable delaying writes on their way to memory
205  *      5 - Write allocate - allocate cache space on write misses
206  *      4 - Write cache - different writes can be merged together
207  *      3 - Override cache attributes
208  *          if 1, bits 4-8 control cache attributes
209  *          if 0, the system bus defaults are used
210  *      2 - Writable
211  *      1 - Readable
212  *      0 - 1 if Page @ Page address is valid
213  */
214 #define RK_PTE_PAGE_ADDRESS_MASK  0xfffff000
215 #define RK_PTE_PAGE_FLAGS_MASK    0x000001fe
216 #define RK_PTE_PAGE_WRITABLE      BIT(2)
217 #define RK_PTE_PAGE_READABLE      BIT(1)
218 #define RK_PTE_PAGE_VALID         BIT(0)
219 
220 static inline phys_addr_t rk_pte_page_address(u32 pte)
221 {
222 	return (phys_addr_t)pte & RK_PTE_PAGE_ADDRESS_MASK;
223 }
224 
225 static inline bool rk_pte_is_page_valid(u32 pte)
226 {
227 	return pte & RK_PTE_PAGE_VALID;
228 }
229 
230 /* TODO: set cache flags per prot IOMMU_CACHE */
231 static u32 rk_mk_pte(phys_addr_t page, int prot)
232 {
233 	u32 flags = 0;
234 	flags |= (prot & IOMMU_READ) ? RK_PTE_PAGE_READABLE : 0;
235 	flags |= (prot & IOMMU_WRITE) ? RK_PTE_PAGE_WRITABLE : 0;
236 	page &= RK_PTE_PAGE_ADDRESS_MASK;
237 	return page | flags | RK_PTE_PAGE_VALID;
238 }
239 
240 static u32 rk_mk_pte_invalid(u32 pte)
241 {
242 	return pte & ~RK_PTE_PAGE_VALID;
243 }
244 
245 /*
246  * rk3288 iova (IOMMU Virtual Address) format
247  *  31       22.21       12.11          0
248  * +-----------+-----------+-------------+
249  * | DTE index | PTE index | Page offset |
250  * +-----------+-----------+-------------+
251  *  31:22 - DTE index   - index of DTE in DT
252  *  21:12 - PTE index   - index of PTE in PT @ DTE.pt_address
253  *  11: 0 - Page offset - offset into page @ PTE.page_address
254  */
255 #define RK_IOVA_DTE_MASK    0xffc00000
256 #define RK_IOVA_DTE_SHIFT   22
257 #define RK_IOVA_PTE_MASK    0x003ff000
258 #define RK_IOVA_PTE_SHIFT   12
259 #define RK_IOVA_PAGE_MASK   0x00000fff
260 #define RK_IOVA_PAGE_SHIFT  0
261 
262 static u32 rk_iova_dte_index(dma_addr_t iova)
263 {
264 	return (u32)(iova & RK_IOVA_DTE_MASK) >> RK_IOVA_DTE_SHIFT;
265 }
266 
267 static u32 rk_iova_pte_index(dma_addr_t iova)
268 {
269 	return (u32)(iova & RK_IOVA_PTE_MASK) >> RK_IOVA_PTE_SHIFT;
270 }
271 
272 static u32 rk_iova_page_offset(dma_addr_t iova)
273 {
274 	return (u32)(iova & RK_IOVA_PAGE_MASK) >> RK_IOVA_PAGE_SHIFT;
275 }
276 
277 static u32 rk_iommu_read(void __iomem *base, u32 offset)
278 {
279 	return readl(base + offset);
280 }
281 
282 static void rk_iommu_write(void __iomem *base, u32 offset, u32 value)
283 {
284 	writel(value, base + offset);
285 }
286 
287 static void rk_iommu_command(struct rk_iommu *iommu, u32 command)
288 {
289 	int i;
290 
291 	for (i = 0; i < iommu->num_mmu; i++)
292 		writel(command, iommu->bases[i] + RK_MMU_COMMAND);
293 }
294 
295 static void rk_iommu_base_command(void __iomem *base, u32 command)
296 {
297 	writel(command, base + RK_MMU_COMMAND);
298 }
299 static void rk_iommu_zap_lines(struct rk_iommu *iommu, dma_addr_t iova,
300 			       size_t size)
301 {
302 	int i;
303 
304 	dma_addr_t iova_end = iova + size;
305 	/*
306 	 * TODO(djkurtz): Figure out when it is more efficient to shootdown the
307 	 * entire iotlb rather than iterate over individual iovas.
308 	 */
309 	for (i = 0; i < iommu->num_mmu; i++)
310 		for (; iova < iova_end; iova += SPAGE_SIZE)
311 			rk_iommu_write(iommu->bases[i], RK_MMU_ZAP_ONE_LINE, iova);
312 }
313 
314 static bool rk_iommu_is_stall_active(struct rk_iommu *iommu)
315 {
316 	bool active = true;
317 	int i;
318 
319 	for (i = 0; i < iommu->num_mmu; i++)
320 		active &= !!(rk_iommu_read(iommu->bases[i], RK_MMU_STATUS) &
321 					   RK_MMU_STATUS_STALL_ACTIVE);
322 
323 	return active;
324 }
325 
326 static bool rk_iommu_is_paging_enabled(struct rk_iommu *iommu)
327 {
328 	bool enable = true;
329 	int i;
330 
331 	for (i = 0; i < iommu->num_mmu; i++)
332 		enable &= !!(rk_iommu_read(iommu->bases[i], RK_MMU_STATUS) &
333 					   RK_MMU_STATUS_PAGING_ENABLED);
334 
335 	return enable;
336 }
337 
338 static int rk_iommu_enable_stall(struct rk_iommu *iommu)
339 {
340 	int ret, i;
341 
342 	if (rk_iommu_is_stall_active(iommu))
343 		return 0;
344 
345 	/* Stall can only be enabled if paging is enabled */
346 	if (!rk_iommu_is_paging_enabled(iommu))
347 		return 0;
348 
349 	rk_iommu_command(iommu, RK_MMU_CMD_ENABLE_STALL);
350 
351 	ret = rk_wait_for(rk_iommu_is_stall_active(iommu), 1);
352 	if (ret)
353 		for (i = 0; i < iommu->num_mmu; i++)
354 			dev_err(iommu->dev, "Enable stall request timed out, status: %#08x\n",
355 				rk_iommu_read(iommu->bases[i], RK_MMU_STATUS));
356 
357 	return ret;
358 }
359 
360 static int rk_iommu_disable_stall(struct rk_iommu *iommu)
361 {
362 	int ret, i;
363 
364 	if (!rk_iommu_is_stall_active(iommu))
365 		return 0;
366 
367 	rk_iommu_command(iommu, RK_MMU_CMD_DISABLE_STALL);
368 
369 	ret = rk_wait_for(!rk_iommu_is_stall_active(iommu), 1);
370 	if (ret)
371 		for (i = 0; i < iommu->num_mmu; i++)
372 			dev_err(iommu->dev, "Disable stall request timed out, status: %#08x\n",
373 				rk_iommu_read(iommu->bases[i], RK_MMU_STATUS));
374 
375 	return ret;
376 }
377 
378 static int rk_iommu_enable_paging(struct rk_iommu *iommu)
379 {
380 	int ret, i;
381 
382 	if (rk_iommu_is_paging_enabled(iommu))
383 		return 0;
384 
385 	rk_iommu_command(iommu, RK_MMU_CMD_ENABLE_PAGING);
386 
387 	ret = rk_wait_for(rk_iommu_is_paging_enabled(iommu), 1);
388 	if (ret)
389 		for (i = 0; i < iommu->num_mmu; i++)
390 			dev_err(iommu->dev, "Enable paging request timed out, status: %#08x\n",
391 				rk_iommu_read(iommu->bases[i], RK_MMU_STATUS));
392 
393 	return ret;
394 }
395 
396 static int rk_iommu_disable_paging(struct rk_iommu *iommu)
397 {
398 	int ret, i;
399 
400 	if (!rk_iommu_is_paging_enabled(iommu))
401 		return 0;
402 
403 	rk_iommu_command(iommu, RK_MMU_CMD_DISABLE_PAGING);
404 
405 	ret = rk_wait_for(!rk_iommu_is_paging_enabled(iommu), 1);
406 	if (ret)
407 		for (i = 0; i < iommu->num_mmu; i++)
408 			dev_err(iommu->dev, "Disable paging request timed out, status: %#08x\n",
409 				rk_iommu_read(iommu->bases[i], RK_MMU_STATUS));
410 
411 	return ret;
412 }
413 
414 static int rk_iommu_force_reset(struct rk_iommu *iommu)
415 {
416 	int ret, i;
417 	u32 dte_addr;
418 
419 	if (iommu->reset_disabled)
420 		return 0;
421 
422 	/*
423 	 * Check if register DTE_ADDR is working by writing DTE_ADDR_DUMMY
424 	 * and verifying that upper 5 nybbles are read back.
425 	 */
426 	for (i = 0; i < iommu->num_mmu; i++) {
427 		rk_iommu_write(iommu->bases[i], RK_MMU_DTE_ADDR, DTE_ADDR_DUMMY);
428 
429 		dte_addr = rk_iommu_read(iommu->bases[i], RK_MMU_DTE_ADDR);
430 		if (dte_addr != (DTE_ADDR_DUMMY & RK_DTE_PT_ADDRESS_MASK)) {
431 			dev_err(iommu->dev, "Error during raw reset. MMU_DTE_ADDR is not functioning\n");
432 			return -EFAULT;
433 		}
434 	}
435 
436 	rk_iommu_command(iommu, RK_MMU_CMD_FORCE_RESET);
437 
438 	for (i = 0; i < iommu->num_mmu; i++) {
439 		ret = rk_wait_for(rk_iommu_read(iommu->bases[i], RK_MMU_DTE_ADDR) == 0x00000000,
440 				  FORCE_RESET_TIMEOUT);
441 		if (ret) {
442 			dev_err(iommu->dev, "FORCE_RESET command timed out\n");
443 			return ret;
444 		}
445 	}
446 
447 	return 0;
448 }
449 
450 static void log_iova(struct rk_iommu *iommu, int index, dma_addr_t iova)
451 {
452 	void __iomem *base = iommu->bases[index];
453 	u32 dte_index, pte_index, page_offset;
454 	u32 mmu_dte_addr;
455 	phys_addr_t mmu_dte_addr_phys, dte_addr_phys;
456 	u32 *dte_addr;
457 	u32 dte;
458 	phys_addr_t pte_addr_phys = 0;
459 	u32 *pte_addr = NULL;
460 	u32 pte = 0;
461 	phys_addr_t page_addr_phys = 0;
462 	u32 page_flags = 0;
463 
464 	dte_index = rk_iova_dte_index(iova);
465 	pte_index = rk_iova_pte_index(iova);
466 	page_offset = rk_iova_page_offset(iova);
467 
468 	mmu_dte_addr = rk_iommu_read(base, RK_MMU_DTE_ADDR);
469 	mmu_dte_addr_phys = (phys_addr_t)mmu_dte_addr;
470 
471 	dte_addr_phys = mmu_dte_addr_phys + (4 * dte_index);
472 	dte_addr = phys_to_virt(dte_addr_phys);
473 	dte = *dte_addr;
474 
475 	if (!rk_dte_is_pt_valid(dte))
476 		goto print_it;
477 
478 	pte_addr_phys = rk_dte_pt_address(dte) + (pte_index * 4);
479 	pte_addr = phys_to_virt(pte_addr_phys);
480 	pte = *pte_addr;
481 
482 	if (!rk_pte_is_page_valid(pte))
483 		goto print_it;
484 
485 	page_addr_phys = rk_pte_page_address(pte) + page_offset;
486 	page_flags = pte & RK_PTE_PAGE_FLAGS_MASK;
487 
488 print_it:
489 	dev_err(iommu->dev, "iova = %pad: dte_index: %#03x pte_index: %#03x page_offset: %#03x\n",
490 		&iova, dte_index, pte_index, page_offset);
491 	dev_err(iommu->dev, "mmu_dte_addr: %pa dte@%pa: %#08x valid: %u pte@%pa: %#08x valid: %u page@%pa flags: %#03x\n",
492 		&mmu_dte_addr_phys, &dte_addr_phys, dte,
493 		rk_dte_is_pt_valid(dte), &pte_addr_phys, pte,
494 		rk_pte_is_page_valid(pte), &page_addr_phys, page_flags);
495 }
496 
497 static irqreturn_t rk_iommu_irq(int irq, void *dev_id)
498 {
499 	struct rk_iommu *iommu = dev_id;
500 	u32 status;
501 	u32 int_status;
502 	dma_addr_t iova;
503 	irqreturn_t ret = IRQ_NONE;
504 	int i;
505 
506 	for (i = 0; i < iommu->num_mmu; i++) {
507 		int_status = rk_iommu_read(iommu->bases[i], RK_MMU_INT_STATUS);
508 		if (int_status == 0)
509 			continue;
510 
511 		ret = IRQ_HANDLED;
512 		iova = rk_iommu_read(iommu->bases[i], RK_MMU_PAGE_FAULT_ADDR);
513 
514 		if (int_status & RK_MMU_IRQ_PAGE_FAULT) {
515 			int flags;
516 
517 			status = rk_iommu_read(iommu->bases[i], RK_MMU_STATUS);
518 			flags = (status & RK_MMU_STATUS_PAGE_FAULT_IS_WRITE) ?
519 					IOMMU_FAULT_WRITE : IOMMU_FAULT_READ;
520 
521 			dev_err(iommu->dev, "Page fault at %pad of type %s\n",
522 				&iova,
523 				(flags == IOMMU_FAULT_WRITE) ? "write" : "read");
524 
525 			log_iova(iommu, i, iova);
526 
527 			/*
528 			 * Report page fault to any installed handlers.
529 			 * Ignore the return code, though, since we always zap cache
530 			 * and clear the page fault anyway.
531 			 */
532 			if (iommu->domain)
533 				report_iommu_fault(iommu->domain, iommu->dev, iova,
534 						   flags);
535 			else
536 				dev_err(iommu->dev, "Page fault while iommu not attached to domain?\n");
537 
538 			rk_iommu_base_command(iommu->bases[i], RK_MMU_CMD_ZAP_CACHE);
539 			rk_iommu_base_command(iommu->bases[i], RK_MMU_CMD_PAGE_FAULT_DONE);
540 		}
541 
542 		if (int_status & RK_MMU_IRQ_BUS_ERROR)
543 			dev_err(iommu->dev, "BUS_ERROR occurred at %pad\n", &iova);
544 
545 		if (int_status & ~RK_MMU_IRQ_MASK)
546 			dev_err(iommu->dev, "unexpected int_status: %#08x\n",
547 				int_status);
548 
549 		rk_iommu_write(iommu->bases[i], RK_MMU_INT_CLEAR, int_status);
550 	}
551 
552 	return ret;
553 }
554 
555 static phys_addr_t rk_iommu_iova_to_phys(struct iommu_domain *domain,
556 					 dma_addr_t iova)
557 {
558 	struct rk_iommu_domain *rk_domain = to_rk_domain(domain);
559 	unsigned long flags;
560 	phys_addr_t pt_phys, phys = 0;
561 	u32 dte, pte;
562 	u32 *page_table;
563 
564 	spin_lock_irqsave(&rk_domain->dt_lock, flags);
565 
566 	dte = rk_domain->dt[rk_iova_dte_index(iova)];
567 	if (!rk_dte_is_pt_valid(dte))
568 		goto out;
569 
570 	pt_phys = rk_dte_pt_address(dte);
571 	page_table = (u32 *)phys_to_virt(pt_phys);
572 	pte = page_table[rk_iova_pte_index(iova)];
573 	if (!rk_pte_is_page_valid(pte))
574 		goto out;
575 
576 	phys = rk_pte_page_address(pte) + rk_iova_page_offset(iova);
577 out:
578 	spin_unlock_irqrestore(&rk_domain->dt_lock, flags);
579 
580 	return phys;
581 }
582 
583 static void rk_iommu_zap_iova(struct rk_iommu_domain *rk_domain,
584 			      dma_addr_t iova, size_t size)
585 {
586 	struct list_head *pos;
587 	unsigned long flags;
588 
589 	/* shootdown these iova from all iommus using this domain */
590 	spin_lock_irqsave(&rk_domain->iommus_lock, flags);
591 	list_for_each(pos, &rk_domain->iommus) {
592 		struct rk_iommu *iommu;
593 		iommu = list_entry(pos, struct rk_iommu, node);
594 		rk_iommu_zap_lines(iommu, iova, size);
595 	}
596 	spin_unlock_irqrestore(&rk_domain->iommus_lock, flags);
597 }
598 
599 static void rk_iommu_zap_iova_first_last(struct rk_iommu_domain *rk_domain,
600 					 dma_addr_t iova, size_t size)
601 {
602 	rk_iommu_zap_iova(rk_domain, iova, SPAGE_SIZE);
603 	if (size > SPAGE_SIZE)
604 		rk_iommu_zap_iova(rk_domain, iova + size - SPAGE_SIZE,
605 					SPAGE_SIZE);
606 }
607 
608 static u32 *rk_dte_get_page_table(struct rk_iommu_domain *rk_domain,
609 				  dma_addr_t iova)
610 {
611 	struct device *dev = &rk_domain->pdev->dev;
612 	u32 *page_table, *dte_addr;
613 	u32 dte_index, dte;
614 	phys_addr_t pt_phys;
615 	dma_addr_t pt_dma;
616 
617 	assert_spin_locked(&rk_domain->dt_lock);
618 
619 	dte_index = rk_iova_dte_index(iova);
620 	dte_addr = &rk_domain->dt[dte_index];
621 	dte = *dte_addr;
622 	if (rk_dte_is_pt_valid(dte))
623 		goto done;
624 
625 	page_table = (u32 *)get_zeroed_page(GFP_ATOMIC | GFP_DMA32);
626 	if (!page_table)
627 		return ERR_PTR(-ENOMEM);
628 
629 	pt_dma = dma_map_single(dev, page_table, SPAGE_SIZE, DMA_TO_DEVICE);
630 	if (dma_mapping_error(dev, pt_dma)) {
631 		dev_err(dev, "DMA mapping error while allocating page table\n");
632 		free_page((unsigned long)page_table);
633 		return ERR_PTR(-ENOMEM);
634 	}
635 
636 	dte = rk_mk_dte(pt_dma);
637 	*dte_addr = dte;
638 
639 	rk_table_flush(rk_domain, pt_dma, NUM_PT_ENTRIES);
640 	rk_table_flush(rk_domain,
641 		       rk_domain->dt_dma + dte_index * sizeof(u32), 1);
642 done:
643 	pt_phys = rk_dte_pt_address(dte);
644 	return (u32 *)phys_to_virt(pt_phys);
645 }
646 
647 static size_t rk_iommu_unmap_iova(struct rk_iommu_domain *rk_domain,
648 				  u32 *pte_addr, dma_addr_t pte_dma,
649 				  size_t size)
650 {
651 	unsigned int pte_count;
652 	unsigned int pte_total = size / SPAGE_SIZE;
653 
654 	assert_spin_locked(&rk_domain->dt_lock);
655 
656 	for (pte_count = 0; pte_count < pte_total; pte_count++) {
657 		u32 pte = pte_addr[pte_count];
658 		if (!rk_pte_is_page_valid(pte))
659 			break;
660 
661 		pte_addr[pte_count] = rk_mk_pte_invalid(pte);
662 	}
663 
664 	rk_table_flush(rk_domain, pte_dma, pte_count);
665 
666 	return pte_count * SPAGE_SIZE;
667 }
668 
669 static int rk_iommu_map_iova(struct rk_iommu_domain *rk_domain, u32 *pte_addr,
670 			     dma_addr_t pte_dma, dma_addr_t iova,
671 			     phys_addr_t paddr, size_t size, int prot)
672 {
673 	unsigned int pte_count;
674 	unsigned int pte_total = size / SPAGE_SIZE;
675 	phys_addr_t page_phys;
676 
677 	assert_spin_locked(&rk_domain->dt_lock);
678 
679 	for (pte_count = 0; pte_count < pte_total; pte_count++) {
680 		u32 pte = pte_addr[pte_count];
681 
682 		if (rk_pte_is_page_valid(pte))
683 			goto unwind;
684 
685 		pte_addr[pte_count] = rk_mk_pte(paddr, prot);
686 
687 		paddr += SPAGE_SIZE;
688 	}
689 
690 	rk_table_flush(rk_domain, pte_dma, pte_total);
691 
692 	/*
693 	 * Zap the first and last iova to evict from iotlb any previously
694 	 * mapped cachelines holding stale values for its dte and pte.
695 	 * We only zap the first and last iova, since only they could have
696 	 * dte or pte shared with an existing mapping.
697 	 */
698 	rk_iommu_zap_iova_first_last(rk_domain, iova, size);
699 
700 	return 0;
701 unwind:
702 	/* Unmap the range of iovas that we just mapped */
703 	rk_iommu_unmap_iova(rk_domain, pte_addr, pte_dma,
704 			    pte_count * SPAGE_SIZE);
705 
706 	iova += pte_count * SPAGE_SIZE;
707 	page_phys = rk_pte_page_address(pte_addr[pte_count]);
708 	pr_err("iova: %pad already mapped to %pa cannot remap to phys: %pa prot: %#x\n",
709 	       &iova, &page_phys, &paddr, prot);
710 
711 	return -EADDRINUSE;
712 }
713 
714 static int rk_iommu_map(struct iommu_domain *domain, unsigned long _iova,
715 			phys_addr_t paddr, size_t size, int prot)
716 {
717 	struct rk_iommu_domain *rk_domain = to_rk_domain(domain);
718 	unsigned long flags;
719 	dma_addr_t pte_dma, iova = (dma_addr_t)_iova;
720 	u32 *page_table, *pte_addr;
721 	u32 dte_index, pte_index;
722 	int ret;
723 
724 	spin_lock_irqsave(&rk_domain->dt_lock, flags);
725 
726 	/*
727 	 * pgsize_bitmap specifies iova sizes that fit in one page table
728 	 * (1024 4-KiB pages = 4 MiB).
729 	 * So, size will always be 4096 <= size <= 4194304.
730 	 * Since iommu_map() guarantees that both iova and size will be
731 	 * aligned, we will always only be mapping from a single dte here.
732 	 */
733 	page_table = rk_dte_get_page_table(rk_domain, iova);
734 	if (IS_ERR(page_table)) {
735 		spin_unlock_irqrestore(&rk_domain->dt_lock, flags);
736 		return PTR_ERR(page_table);
737 	}
738 
739 	dte_index = rk_domain->dt[rk_iova_dte_index(iova)];
740 	pte_index = rk_iova_pte_index(iova);
741 	pte_addr = &page_table[pte_index];
742 	pte_dma = rk_dte_pt_address(dte_index) + pte_index * sizeof(u32);
743 	ret = rk_iommu_map_iova(rk_domain, pte_addr, pte_dma, iova,
744 				paddr, size, prot);
745 
746 	spin_unlock_irqrestore(&rk_domain->dt_lock, flags);
747 
748 	return ret;
749 }
750 
751 static size_t rk_iommu_unmap(struct iommu_domain *domain, unsigned long _iova,
752 			     size_t size)
753 {
754 	struct rk_iommu_domain *rk_domain = to_rk_domain(domain);
755 	unsigned long flags;
756 	dma_addr_t pte_dma, iova = (dma_addr_t)_iova;
757 	phys_addr_t pt_phys;
758 	u32 dte;
759 	u32 *pte_addr;
760 	size_t unmap_size;
761 
762 	spin_lock_irqsave(&rk_domain->dt_lock, flags);
763 
764 	/*
765 	 * pgsize_bitmap specifies iova sizes that fit in one page table
766 	 * (1024 4-KiB pages = 4 MiB).
767 	 * So, size will always be 4096 <= size <= 4194304.
768 	 * Since iommu_unmap() guarantees that both iova and size will be
769 	 * aligned, we will always only be unmapping from a single dte here.
770 	 */
771 	dte = rk_domain->dt[rk_iova_dte_index(iova)];
772 	/* Just return 0 if iova is unmapped */
773 	if (!rk_dte_is_pt_valid(dte)) {
774 		spin_unlock_irqrestore(&rk_domain->dt_lock, flags);
775 		return 0;
776 	}
777 
778 	pt_phys = rk_dte_pt_address(dte);
779 	pte_addr = (u32 *)phys_to_virt(pt_phys) + rk_iova_pte_index(iova);
780 	pte_dma = pt_phys + rk_iova_pte_index(iova) * sizeof(u32);
781 	unmap_size = rk_iommu_unmap_iova(rk_domain, pte_addr, pte_dma, size);
782 
783 	spin_unlock_irqrestore(&rk_domain->dt_lock, flags);
784 
785 	/* Shootdown iotlb entries for iova range that was just unmapped */
786 	rk_iommu_zap_iova(rk_domain, iova, unmap_size);
787 
788 	return unmap_size;
789 }
790 
791 static struct rk_iommu *rk_iommu_from_dev(struct device *dev)
792 {
793 	struct iommu_group *group;
794 	struct device *iommu_dev;
795 	struct rk_iommu *rk_iommu;
796 
797 	group = iommu_group_get(dev);
798 	if (!group)
799 		return NULL;
800 	iommu_dev = iommu_group_get_iommudata(group);
801 	rk_iommu = dev_get_drvdata(iommu_dev);
802 	iommu_group_put(group);
803 
804 	return rk_iommu;
805 }
806 
807 static int rk_iommu_attach_device(struct iommu_domain *domain,
808 				  struct device *dev)
809 {
810 	struct rk_iommu *iommu;
811 	struct rk_iommu_domain *rk_domain = to_rk_domain(domain);
812 	unsigned long flags;
813 	int ret, i;
814 
815 	/*
816 	 * Allow 'virtual devices' (e.g., drm) to attach to domain.
817 	 * Such a device does not belong to an iommu group.
818 	 */
819 	iommu = rk_iommu_from_dev(dev);
820 	if (!iommu)
821 		return 0;
822 
823 	ret = rk_iommu_enable_stall(iommu);
824 	if (ret)
825 		return ret;
826 
827 	ret = rk_iommu_force_reset(iommu);
828 	if (ret)
829 		return ret;
830 
831 	iommu->domain = domain;
832 
833 	for (i = 0; i < iommu->num_irq; i++) {
834 		ret = devm_request_irq(iommu->dev, iommu->irq[i], rk_iommu_irq,
835 				       IRQF_SHARED, dev_name(dev), iommu);
836 		if (ret)
837 			return ret;
838 	}
839 
840 	for (i = 0; i < iommu->num_mmu; i++) {
841 		rk_iommu_write(iommu->bases[i], RK_MMU_DTE_ADDR,
842 			       rk_domain->dt_dma);
843 		rk_iommu_base_command(iommu->bases[i], RK_MMU_CMD_ZAP_CACHE);
844 		rk_iommu_write(iommu->bases[i], RK_MMU_INT_MASK, RK_MMU_IRQ_MASK);
845 	}
846 
847 	ret = rk_iommu_enable_paging(iommu);
848 	if (ret)
849 		return ret;
850 
851 	spin_lock_irqsave(&rk_domain->iommus_lock, flags);
852 	list_add_tail(&iommu->node, &rk_domain->iommus);
853 	spin_unlock_irqrestore(&rk_domain->iommus_lock, flags);
854 
855 	dev_dbg(dev, "Attached to iommu domain\n");
856 
857 	rk_iommu_disable_stall(iommu);
858 
859 	return 0;
860 }
861 
862 static void rk_iommu_detach_device(struct iommu_domain *domain,
863 				   struct device *dev)
864 {
865 	struct rk_iommu *iommu;
866 	struct rk_iommu_domain *rk_domain = to_rk_domain(domain);
867 	unsigned long flags;
868 	int i;
869 
870 	/* Allow 'virtual devices' (eg drm) to detach from domain */
871 	iommu = rk_iommu_from_dev(dev);
872 	if (!iommu)
873 		return;
874 
875 	spin_lock_irqsave(&rk_domain->iommus_lock, flags);
876 	list_del_init(&iommu->node);
877 	spin_unlock_irqrestore(&rk_domain->iommus_lock, flags);
878 
879 	/* Ignore error while disabling, just keep going */
880 	rk_iommu_enable_stall(iommu);
881 	rk_iommu_disable_paging(iommu);
882 	for (i = 0; i < iommu->num_mmu; i++) {
883 		rk_iommu_write(iommu->bases[i], RK_MMU_INT_MASK, 0);
884 		rk_iommu_write(iommu->bases[i], RK_MMU_DTE_ADDR, 0);
885 	}
886 	rk_iommu_disable_stall(iommu);
887 
888 	for (i = 0; i < iommu->num_irq; i++)
889 		devm_free_irq(iommu->dev, iommu->irq[i], iommu);
890 
891 	iommu->domain = NULL;
892 
893 	dev_dbg(dev, "Detached from iommu domain\n");
894 }
895 
896 static struct iommu_domain *rk_iommu_domain_alloc(unsigned type)
897 {
898 	struct rk_iommu_domain *rk_domain;
899 	struct platform_device *pdev;
900 	struct device *iommu_dev;
901 
902 	if (type != IOMMU_DOMAIN_UNMANAGED && type != IOMMU_DOMAIN_DMA)
903 		return NULL;
904 
905 	/* Register a pdev per domain, so DMA API can base on this *dev
906 	 * even some virtual master doesn't have an iommu slave
907 	 */
908 	pdev = platform_device_register_simple("rk_iommu_domain",
909 					       PLATFORM_DEVID_AUTO, NULL, 0);
910 	if (IS_ERR(pdev))
911 		return NULL;
912 
913 	rk_domain = devm_kzalloc(&pdev->dev, sizeof(*rk_domain), GFP_KERNEL);
914 	if (!rk_domain)
915 		goto err_unreg_pdev;
916 
917 	rk_domain->pdev = pdev;
918 
919 	if (type == IOMMU_DOMAIN_DMA &&
920 	    iommu_get_dma_cookie(&rk_domain->domain))
921 		goto err_unreg_pdev;
922 
923 	/*
924 	 * rk32xx iommus use a 2 level pagetable.
925 	 * Each level1 (dt) and level2 (pt) table has 1024 4-byte entries.
926 	 * Allocate one 4 KiB page for each table.
927 	 */
928 	rk_domain->dt = (u32 *)get_zeroed_page(GFP_KERNEL | GFP_DMA32);
929 	if (!rk_domain->dt)
930 		goto err_put_cookie;
931 
932 	iommu_dev = &pdev->dev;
933 	rk_domain->dt_dma = dma_map_single(iommu_dev, rk_domain->dt,
934 					   SPAGE_SIZE, DMA_TO_DEVICE);
935 	if (dma_mapping_error(iommu_dev, rk_domain->dt_dma)) {
936 		dev_err(iommu_dev, "DMA map error for DT\n");
937 		goto err_free_dt;
938 	}
939 
940 	rk_table_flush(rk_domain, rk_domain->dt_dma, NUM_DT_ENTRIES);
941 
942 	spin_lock_init(&rk_domain->iommus_lock);
943 	spin_lock_init(&rk_domain->dt_lock);
944 	INIT_LIST_HEAD(&rk_domain->iommus);
945 
946 	rk_domain->domain.geometry.aperture_start = 0;
947 	rk_domain->domain.geometry.aperture_end   = DMA_BIT_MASK(32);
948 	rk_domain->domain.geometry.force_aperture = true;
949 
950 	return &rk_domain->domain;
951 
952 err_free_dt:
953 	free_page((unsigned long)rk_domain->dt);
954 err_put_cookie:
955 	if (type == IOMMU_DOMAIN_DMA)
956 		iommu_put_dma_cookie(&rk_domain->domain);
957 err_unreg_pdev:
958 	platform_device_unregister(pdev);
959 
960 	return NULL;
961 }
962 
963 static void rk_iommu_domain_free(struct iommu_domain *domain)
964 {
965 	struct rk_iommu_domain *rk_domain = to_rk_domain(domain);
966 	int i;
967 
968 	WARN_ON(!list_empty(&rk_domain->iommus));
969 
970 	for (i = 0; i < NUM_DT_ENTRIES; i++) {
971 		u32 dte = rk_domain->dt[i];
972 		if (rk_dte_is_pt_valid(dte)) {
973 			phys_addr_t pt_phys = rk_dte_pt_address(dte);
974 			u32 *page_table = phys_to_virt(pt_phys);
975 			dma_unmap_single(&rk_domain->pdev->dev, pt_phys,
976 					 SPAGE_SIZE, DMA_TO_DEVICE);
977 			free_page((unsigned long)page_table);
978 		}
979 	}
980 
981 	dma_unmap_single(&rk_domain->pdev->dev, rk_domain->dt_dma,
982 			 SPAGE_SIZE, DMA_TO_DEVICE);
983 	free_page((unsigned long)rk_domain->dt);
984 
985 	if (domain->type == IOMMU_DOMAIN_DMA)
986 		iommu_put_dma_cookie(&rk_domain->domain);
987 
988 	platform_device_unregister(rk_domain->pdev);
989 }
990 
991 static bool rk_iommu_is_dev_iommu_master(struct device *dev)
992 {
993 	struct device_node *np = dev->of_node;
994 	int ret;
995 
996 	/*
997 	 * An iommu master has an iommus property containing a list of phandles
998 	 * to iommu nodes, each with an #iommu-cells property with value 0.
999 	 */
1000 	ret = of_count_phandle_with_args(np, "iommus", "#iommu-cells");
1001 	return (ret > 0);
1002 }
1003 
1004 static int rk_iommu_group_set_iommudata(struct iommu_group *group,
1005 					struct device *dev)
1006 {
1007 	struct device_node *np = dev->of_node;
1008 	struct platform_device *pd;
1009 	int ret;
1010 	struct of_phandle_args args;
1011 
1012 	/*
1013 	 * An iommu master has an iommus property containing a list of phandles
1014 	 * to iommu nodes, each with an #iommu-cells property with value 0.
1015 	 */
1016 	ret = of_parse_phandle_with_args(np, "iommus", "#iommu-cells", 0,
1017 					 &args);
1018 	if (ret) {
1019 		dev_err(dev, "of_parse_phandle_with_args(%pOF) => %d\n",
1020 			np, ret);
1021 		return ret;
1022 	}
1023 	if (args.args_count != 0) {
1024 		dev_err(dev, "incorrect number of iommu params found for %pOF (found %d, expected 0)\n",
1025 			args.np, args.args_count);
1026 		return -EINVAL;
1027 	}
1028 
1029 	pd = of_find_device_by_node(args.np);
1030 	of_node_put(args.np);
1031 	if (!pd) {
1032 		dev_err(dev, "iommu %pOF not found\n", args.np);
1033 		return -EPROBE_DEFER;
1034 	}
1035 
1036 	/* TODO(djkurtz): handle multiple slave iommus for a single master */
1037 	iommu_group_set_iommudata(group, &pd->dev, NULL);
1038 
1039 	return 0;
1040 }
1041 
1042 static int rk_iommu_add_device(struct device *dev)
1043 {
1044 	struct iommu_group *group;
1045 	struct rk_iommu *iommu;
1046 	int ret;
1047 
1048 	if (!rk_iommu_is_dev_iommu_master(dev))
1049 		return -ENODEV;
1050 
1051 	group = iommu_group_get(dev);
1052 	if (!group) {
1053 		group = iommu_group_alloc();
1054 		if (IS_ERR(group)) {
1055 			dev_err(dev, "Failed to allocate IOMMU group\n");
1056 			return PTR_ERR(group);
1057 		}
1058 	}
1059 
1060 	ret = iommu_group_add_device(group, dev);
1061 	if (ret)
1062 		goto err_put_group;
1063 
1064 	ret = rk_iommu_group_set_iommudata(group, dev);
1065 	if (ret)
1066 		goto err_remove_device;
1067 
1068 	iommu = rk_iommu_from_dev(dev);
1069 	if (iommu)
1070 		iommu_device_link(&iommu->iommu, dev);
1071 
1072 	iommu_group_put(group);
1073 
1074 	return 0;
1075 
1076 err_remove_device:
1077 	iommu_group_remove_device(dev);
1078 err_put_group:
1079 	iommu_group_put(group);
1080 	return ret;
1081 }
1082 
1083 static void rk_iommu_remove_device(struct device *dev)
1084 {
1085 	struct rk_iommu *iommu;
1086 
1087 	if (!rk_iommu_is_dev_iommu_master(dev))
1088 		return;
1089 
1090 	iommu = rk_iommu_from_dev(dev);
1091 	if (iommu)
1092 		iommu_device_unlink(&iommu->iommu, dev);
1093 
1094 	iommu_group_remove_device(dev);
1095 }
1096 
1097 static const struct iommu_ops rk_iommu_ops = {
1098 	.domain_alloc = rk_iommu_domain_alloc,
1099 	.domain_free = rk_iommu_domain_free,
1100 	.attach_dev = rk_iommu_attach_device,
1101 	.detach_dev = rk_iommu_detach_device,
1102 	.map = rk_iommu_map,
1103 	.unmap = rk_iommu_unmap,
1104 	.map_sg = default_iommu_map_sg,
1105 	.add_device = rk_iommu_add_device,
1106 	.remove_device = rk_iommu_remove_device,
1107 	.iova_to_phys = rk_iommu_iova_to_phys,
1108 	.pgsize_bitmap = RK_IOMMU_PGSIZE_BITMAP,
1109 };
1110 
1111 static int rk_iommu_domain_probe(struct platform_device *pdev)
1112 {
1113 	struct device *dev = &pdev->dev;
1114 
1115 	dev->dma_parms = devm_kzalloc(dev, sizeof(*dev->dma_parms), GFP_KERNEL);
1116 	if (!dev->dma_parms)
1117 		return -ENOMEM;
1118 
1119 	/* Set dma_ops for dev, otherwise it would be dummy_dma_ops */
1120 	arch_setup_dma_ops(dev, 0, DMA_BIT_MASK(32), NULL, false);
1121 
1122 	dma_set_max_seg_size(dev, DMA_BIT_MASK(32));
1123 	dma_coerce_mask_and_coherent(dev, DMA_BIT_MASK(32));
1124 
1125 	return 0;
1126 }
1127 
1128 static struct platform_driver rk_iommu_domain_driver = {
1129 	.probe = rk_iommu_domain_probe,
1130 	.driver = {
1131 		   .name = "rk_iommu_domain",
1132 	},
1133 };
1134 
1135 static int rk_iommu_probe(struct platform_device *pdev)
1136 {
1137 	struct device *dev = &pdev->dev;
1138 	struct rk_iommu *iommu;
1139 	struct resource *res;
1140 	int num_res = pdev->num_resources;
1141 	int err, i;
1142 
1143 	iommu = devm_kzalloc(dev, sizeof(*iommu), GFP_KERNEL);
1144 	if (!iommu)
1145 		return -ENOMEM;
1146 
1147 	platform_set_drvdata(pdev, iommu);
1148 	iommu->dev = dev;
1149 	iommu->num_mmu = 0;
1150 
1151 	iommu->bases = devm_kzalloc(dev, sizeof(*iommu->bases) * num_res,
1152 				    GFP_KERNEL);
1153 	if (!iommu->bases)
1154 		return -ENOMEM;
1155 
1156 	for (i = 0; i < num_res; i++) {
1157 		res = platform_get_resource(pdev, IORESOURCE_MEM, i);
1158 		if (!res)
1159 			continue;
1160 		iommu->bases[i] = devm_ioremap_resource(&pdev->dev, res);
1161 		if (IS_ERR(iommu->bases[i]))
1162 			continue;
1163 		iommu->num_mmu++;
1164 	}
1165 	if (iommu->num_mmu == 0)
1166 		return PTR_ERR(iommu->bases[0]);
1167 
1168 	iommu->num_irq = platform_irq_count(pdev);
1169 	if (iommu->num_irq < 0)
1170 		return iommu->num_irq;
1171 	if (iommu->num_irq == 0)
1172 		return -ENXIO;
1173 
1174 	iommu->irq = devm_kcalloc(dev, iommu->num_irq, sizeof(*iommu->irq),
1175 				  GFP_KERNEL);
1176 	if (!iommu->irq)
1177 		return -ENOMEM;
1178 
1179 	for (i = 0; i < iommu->num_irq; i++) {
1180 		iommu->irq[i] = platform_get_irq(pdev, i);
1181 		if (iommu->irq[i] < 0) {
1182 			dev_err(dev, "Failed to get IRQ, %d\n", iommu->irq[i]);
1183 			return -ENXIO;
1184 		}
1185 	}
1186 
1187 	iommu->reset_disabled = device_property_read_bool(dev,
1188 					"rockchip,disable-mmu-reset");
1189 
1190 	err = iommu_device_sysfs_add(&iommu->iommu, dev, NULL, dev_name(dev));
1191 	if (err)
1192 		return err;
1193 
1194 	iommu_device_set_ops(&iommu->iommu, &rk_iommu_ops);
1195 	err = iommu_device_register(&iommu->iommu);
1196 
1197 	return err;
1198 }
1199 
1200 static int rk_iommu_remove(struct platform_device *pdev)
1201 {
1202 	struct rk_iommu *iommu = platform_get_drvdata(pdev);
1203 
1204 	if (iommu) {
1205 		iommu_device_sysfs_remove(&iommu->iommu);
1206 		iommu_device_unregister(&iommu->iommu);
1207 	}
1208 
1209 	return 0;
1210 }
1211 
1212 static const struct of_device_id rk_iommu_dt_ids[] = {
1213 	{ .compatible = "rockchip,iommu" },
1214 	{ /* sentinel */ }
1215 };
1216 MODULE_DEVICE_TABLE(of, rk_iommu_dt_ids);
1217 
1218 static struct platform_driver rk_iommu_driver = {
1219 	.probe = rk_iommu_probe,
1220 	.remove = rk_iommu_remove,
1221 	.driver = {
1222 		   .name = "rk_iommu",
1223 		   .of_match_table = rk_iommu_dt_ids,
1224 	},
1225 };
1226 
1227 static int __init rk_iommu_init(void)
1228 {
1229 	struct device_node *np;
1230 	int ret;
1231 
1232 	np = of_find_matching_node(NULL, rk_iommu_dt_ids);
1233 	if (!np)
1234 		return 0;
1235 
1236 	of_node_put(np);
1237 
1238 	ret = bus_set_iommu(&platform_bus_type, &rk_iommu_ops);
1239 	if (ret)
1240 		return ret;
1241 
1242 	ret = platform_driver_register(&rk_iommu_domain_driver);
1243 	if (ret)
1244 		return ret;
1245 
1246 	ret = platform_driver_register(&rk_iommu_driver);
1247 	if (ret)
1248 		platform_driver_unregister(&rk_iommu_domain_driver);
1249 	return ret;
1250 }
1251 static void __exit rk_iommu_exit(void)
1252 {
1253 	platform_driver_unregister(&rk_iommu_driver);
1254 	platform_driver_unregister(&rk_iommu_domain_driver);
1255 }
1256 
1257 subsys_initcall(rk_iommu_init);
1258 module_exit(rk_iommu_exit);
1259 
1260 MODULE_DESCRIPTION("IOMMU API for Rockchip");
1261 MODULE_AUTHOR("Simon Xue <xxm@rock-chips.com> and Daniel Kurtz <djkurtz@chromium.org>");
1262 MODULE_ALIAS("platform:rockchip-iommu");
1263 MODULE_LICENSE("GPL v2");
1264