xref: /openbmc/linux/drivers/iommu/sun50i-iommu.c (revision ac73d4bf)
1 // SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
2 // Copyright (C) 2016-2018, Allwinner Technology CO., LTD.
3 // Copyright (C) 2019-2020, Cerno
4 
5 #include <linux/bitfield.h>
6 #include <linux/bug.h>
7 #include <linux/clk.h>
8 #include <linux/device.h>
9 #include <linux/dma-direction.h>
10 #include <linux/dma-mapping.h>
11 #include <linux/err.h>
12 #include <linux/errno.h>
13 #include <linux/interrupt.h>
14 #include <linux/iommu.h>
15 #include <linux/iopoll.h>
16 #include <linux/ioport.h>
17 #include <linux/log2.h>
18 #include <linux/module.h>
19 #include <linux/of_platform.h>
20 #include <linux/platform_device.h>
21 #include <linux/pm.h>
22 #include <linux/pm_runtime.h>
23 #include <linux/reset.h>
24 #include <linux/sizes.h>
25 #include <linux/slab.h>
26 #include <linux/spinlock.h>
27 #include <linux/types.h>
28 
29 #define IOMMU_RESET_REG			0x010
30 #define IOMMU_ENABLE_REG		0x020
31 #define IOMMU_ENABLE_ENABLE			BIT(0)
32 
33 #define IOMMU_BYPASS_REG		0x030
34 #define IOMMU_AUTO_GATING_REG		0x040
35 #define IOMMU_AUTO_GATING_ENABLE		BIT(0)
36 
37 #define IOMMU_WBUF_CTRL_REG		0x044
38 #define IOMMU_OOO_CTRL_REG		0x048
39 #define IOMMU_4KB_BDY_PRT_CTRL_REG	0x04c
40 #define IOMMU_TTB_REG			0x050
41 #define IOMMU_TLB_ENABLE_REG		0x060
42 #define IOMMU_TLB_PREFETCH_REG		0x070
43 #define IOMMU_TLB_PREFETCH_MASTER_ENABLE(m)	BIT(m)
44 
45 #define IOMMU_TLB_FLUSH_REG		0x080
46 #define IOMMU_TLB_FLUSH_PTW_CACHE		BIT(17)
47 #define IOMMU_TLB_FLUSH_MACRO_TLB		BIT(16)
48 #define IOMMU_TLB_FLUSH_MICRO_TLB(i)		(BIT(i) & GENMASK(5, 0))
49 
50 #define IOMMU_TLB_IVLD_ADDR_REG		0x090
51 #define IOMMU_TLB_IVLD_ADDR_MASK_REG	0x094
52 #define IOMMU_TLB_IVLD_ENABLE_REG	0x098
53 #define IOMMU_TLB_IVLD_ENABLE_ENABLE		BIT(0)
54 
55 #define IOMMU_PC_IVLD_ADDR_REG		0x0a0
56 #define IOMMU_PC_IVLD_ENABLE_REG	0x0a8
57 #define IOMMU_PC_IVLD_ENABLE_ENABLE		BIT(0)
58 
59 #define IOMMU_DM_AUT_CTRL_REG(d)	(0x0b0 + ((d) / 2) * 4)
60 #define IOMMU_DM_AUT_CTRL_RD_UNAVAIL(d, m)	(1 << (((d & 1) * 16) + ((m) * 2)))
61 #define IOMMU_DM_AUT_CTRL_WR_UNAVAIL(d, m)	(1 << (((d & 1) * 16) + ((m) * 2) + 1))
62 
63 #define IOMMU_DM_AUT_OVWT_REG		0x0d0
64 #define IOMMU_INT_ENABLE_REG		0x100
65 #define IOMMU_INT_CLR_REG		0x104
66 #define IOMMU_INT_STA_REG		0x108
67 #define IOMMU_INT_ERR_ADDR_REG(i)	(0x110 + (i) * 4)
68 #define IOMMU_INT_ERR_ADDR_L1_REG	0x130
69 #define IOMMU_INT_ERR_ADDR_L2_REG	0x134
70 #define IOMMU_INT_ERR_DATA_REG(i)	(0x150 + (i) * 4)
71 #define IOMMU_L1PG_INT_REG		0x0180
72 #define IOMMU_L2PG_INT_REG		0x0184
73 
74 #define IOMMU_INT_INVALID_L2PG			BIT(17)
75 #define IOMMU_INT_INVALID_L1PG			BIT(16)
76 #define IOMMU_INT_MASTER_PERMISSION(m)		BIT(m)
77 #define IOMMU_INT_MASTER_MASK			(IOMMU_INT_MASTER_PERMISSION(0) | \
78 						 IOMMU_INT_MASTER_PERMISSION(1) | \
79 						 IOMMU_INT_MASTER_PERMISSION(2) | \
80 						 IOMMU_INT_MASTER_PERMISSION(3) | \
81 						 IOMMU_INT_MASTER_PERMISSION(4) | \
82 						 IOMMU_INT_MASTER_PERMISSION(5))
83 #define IOMMU_INT_MASK				(IOMMU_INT_INVALID_L1PG | \
84 						 IOMMU_INT_INVALID_L2PG | \
85 						 IOMMU_INT_MASTER_MASK)
86 
87 #define PT_ENTRY_SIZE			sizeof(u32)
88 
89 #define NUM_DT_ENTRIES			4096
90 #define DT_SIZE				(NUM_DT_ENTRIES * PT_ENTRY_SIZE)
91 
92 #define NUM_PT_ENTRIES			256
93 #define PT_SIZE				(NUM_PT_ENTRIES * PT_ENTRY_SIZE)
94 
95 struct sun50i_iommu {
96 	struct iommu_device iommu;
97 
98 	/* Lock to modify the IOMMU registers */
99 	spinlock_t iommu_lock;
100 
101 	struct device *dev;
102 	void __iomem *base;
103 	struct reset_control *reset;
104 	struct clk *clk;
105 
106 	struct iommu_domain *domain;
107 	struct iommu_group *group;
108 	struct kmem_cache *pt_pool;
109 };
110 
111 struct sun50i_iommu_domain {
112 	struct iommu_domain domain;
113 
114 	/* Number of devices attached to the domain */
115 	refcount_t refcnt;
116 
117 	/* L1 Page Table */
118 	u32 *dt;
119 	dma_addr_t dt_dma;
120 
121 	struct sun50i_iommu *iommu;
122 };
123 
124 static struct sun50i_iommu_domain *to_sun50i_domain(struct iommu_domain *domain)
125 {
126 	return container_of(domain, struct sun50i_iommu_domain, domain);
127 }
128 
129 static struct sun50i_iommu *sun50i_iommu_from_dev(struct device *dev)
130 {
131 	return dev_iommu_priv_get(dev);
132 }
133 
134 static u32 iommu_read(struct sun50i_iommu *iommu, u32 offset)
135 {
136 	return readl(iommu->base + offset);
137 }
138 
139 static void iommu_write(struct sun50i_iommu *iommu, u32 offset, u32 value)
140 {
141 	writel(value, iommu->base + offset);
142 }
143 
144 /*
145  * The Allwinner H6 IOMMU uses a 2-level page table.
146  *
147  * The first level is the usual Directory Table (DT), that consists of
148  * 4096 4-bytes Directory Table Entries (DTE), each pointing to a Page
149  * Table (PT).
150  *
151  * Each PT consits of 256 4-bytes Page Table Entries (PTE), each
152  * pointing to a 4kB page of physical memory.
153  *
154  * The IOMMU supports a single DT, pointed by the IOMMU_TTB_REG
155  * register that contains its physical address.
156  */
157 
158 #define SUN50I_IOVA_DTE_MASK	GENMASK(31, 20)
159 #define SUN50I_IOVA_PTE_MASK	GENMASK(19, 12)
160 #define SUN50I_IOVA_PAGE_MASK	GENMASK(11, 0)
161 
162 static u32 sun50i_iova_get_dte_index(dma_addr_t iova)
163 {
164 	return FIELD_GET(SUN50I_IOVA_DTE_MASK, iova);
165 }
166 
167 static u32 sun50i_iova_get_pte_index(dma_addr_t iova)
168 {
169 	return FIELD_GET(SUN50I_IOVA_PTE_MASK, iova);
170 }
171 
172 static u32 sun50i_iova_get_page_offset(dma_addr_t iova)
173 {
174 	return FIELD_GET(SUN50I_IOVA_PAGE_MASK, iova);
175 }
176 
177 /*
178  * Each Directory Table Entry has a Page Table address and a valid
179  * bit:
180 
181  * +---------------------+-----------+-+
182  * | PT address          | Reserved  |V|
183  * +---------------------+-----------+-+
184  *  31:10 - Page Table address
185  *   9:2  - Reserved
186  *   1:0  - 1 if the entry is valid
187  */
188 
189 #define SUN50I_DTE_PT_ADDRESS_MASK	GENMASK(31, 10)
190 #define SUN50I_DTE_PT_ATTRS		GENMASK(1, 0)
191 #define SUN50I_DTE_PT_VALID		1
192 
193 static phys_addr_t sun50i_dte_get_pt_address(u32 dte)
194 {
195 	return (phys_addr_t)dte & SUN50I_DTE_PT_ADDRESS_MASK;
196 }
197 
198 static bool sun50i_dte_is_pt_valid(u32 dte)
199 {
200 	return (dte & SUN50I_DTE_PT_ATTRS) == SUN50I_DTE_PT_VALID;
201 }
202 
203 static u32 sun50i_mk_dte(dma_addr_t pt_dma)
204 {
205 	return (pt_dma & SUN50I_DTE_PT_ADDRESS_MASK) | SUN50I_DTE_PT_VALID;
206 }
207 
208 /*
209  * Each PTE has a Page address, an authority index and a valid bit:
210  *
211  * +----------------+-----+-----+-----+---+-----+
212  * | Page address   | Rsv | ACI | Rsv | V | Rsv |
213  * +----------------+-----+-----+-----+---+-----+
214  *  31:12 - Page address
215  *  11:8  - Reserved
216  *   7:4  - Authority Control Index
217  *   3:2  - Reserved
218  *     1  - 1 if the entry is valid
219  *     0  - Reserved
220  *
221  * The way permissions work is that the IOMMU has 16 "domains" that
222  * can be configured to give each masters either read or write
223  * permissions through the IOMMU_DM_AUT_CTRL_REG registers. The domain
224  * 0 seems like the default domain, and its permissions in the
225  * IOMMU_DM_AUT_CTRL_REG are only read-only, so it's not really
226  * useful to enforce any particular permission.
227  *
228  * Each page entry will then have a reference to the domain they are
229  * affected to, so that we can actually enforce them on a per-page
230  * basis.
231  *
232  * In order to make it work with the IOMMU framework, we will be using
233  * 4 different domains, starting at 1: RD_WR, RD, WR and NONE
234  * depending on the permission we want to enforce. Each domain will
235  * have each master setup in the same way, since the IOMMU framework
236  * doesn't seem to restrict page access on a per-device basis. And
237  * then we will use the relevant domain index when generating the page
238  * table entry depending on the permissions we want to be enforced.
239  */
240 
241 enum sun50i_iommu_aci {
242 	SUN50I_IOMMU_ACI_DO_NOT_USE = 0,
243 	SUN50I_IOMMU_ACI_NONE,
244 	SUN50I_IOMMU_ACI_RD,
245 	SUN50I_IOMMU_ACI_WR,
246 	SUN50I_IOMMU_ACI_RD_WR,
247 };
248 
249 #define SUN50I_PTE_PAGE_ADDRESS_MASK	GENMASK(31, 12)
250 #define SUN50I_PTE_ACI_MASK		GENMASK(7, 4)
251 #define SUN50I_PTE_PAGE_VALID		BIT(1)
252 
253 static phys_addr_t sun50i_pte_get_page_address(u32 pte)
254 {
255 	return (phys_addr_t)pte & SUN50I_PTE_PAGE_ADDRESS_MASK;
256 }
257 
258 static enum sun50i_iommu_aci sun50i_get_pte_aci(u32 pte)
259 {
260 	return FIELD_GET(SUN50I_PTE_ACI_MASK, pte);
261 }
262 
263 static bool sun50i_pte_is_page_valid(u32 pte)
264 {
265 	return pte & SUN50I_PTE_PAGE_VALID;
266 }
267 
268 static u32 sun50i_mk_pte(phys_addr_t page, int prot)
269 {
270 	enum sun50i_iommu_aci aci;
271 	u32 flags = 0;
272 
273 	if (prot & (IOMMU_READ | IOMMU_WRITE))
274 		aci = SUN50I_IOMMU_ACI_RD_WR;
275 	else if (prot & IOMMU_READ)
276 		aci = SUN50I_IOMMU_ACI_RD;
277 	else if (prot & IOMMU_WRITE)
278 		aci = SUN50I_IOMMU_ACI_WR;
279 	else
280 		aci = SUN50I_IOMMU_ACI_NONE;
281 
282 	flags |= FIELD_PREP(SUN50I_PTE_ACI_MASK, aci);
283 	page &= SUN50I_PTE_PAGE_ADDRESS_MASK;
284 	return page | flags | SUN50I_PTE_PAGE_VALID;
285 }
286 
287 static void sun50i_table_flush(struct sun50i_iommu_domain *sun50i_domain,
288 			       void *vaddr, unsigned int count)
289 {
290 	struct sun50i_iommu *iommu = sun50i_domain->iommu;
291 	dma_addr_t dma = virt_to_phys(vaddr);
292 	size_t size = count * PT_ENTRY_SIZE;
293 
294 	dma_sync_single_for_device(iommu->dev, dma, size, DMA_TO_DEVICE);
295 }
296 
297 static int sun50i_iommu_flush_all_tlb(struct sun50i_iommu *iommu)
298 {
299 	u32 reg;
300 	int ret;
301 
302 	assert_spin_locked(&iommu->iommu_lock);
303 
304 	iommu_write(iommu,
305 		    IOMMU_TLB_FLUSH_REG,
306 		    IOMMU_TLB_FLUSH_PTW_CACHE |
307 		    IOMMU_TLB_FLUSH_MACRO_TLB |
308 		    IOMMU_TLB_FLUSH_MICRO_TLB(5) |
309 		    IOMMU_TLB_FLUSH_MICRO_TLB(4) |
310 		    IOMMU_TLB_FLUSH_MICRO_TLB(3) |
311 		    IOMMU_TLB_FLUSH_MICRO_TLB(2) |
312 		    IOMMU_TLB_FLUSH_MICRO_TLB(1) |
313 		    IOMMU_TLB_FLUSH_MICRO_TLB(0));
314 
315 	ret = readl_poll_timeout_atomic(iommu->base + IOMMU_TLB_FLUSH_REG,
316 					reg, !reg,
317 					1, 2000);
318 	if (ret)
319 		dev_warn(iommu->dev, "TLB Flush timed out!\n");
320 
321 	return ret;
322 }
323 
324 static void sun50i_iommu_flush_iotlb_all(struct iommu_domain *domain)
325 {
326 	struct sun50i_iommu_domain *sun50i_domain = to_sun50i_domain(domain);
327 	struct sun50i_iommu *iommu = sun50i_domain->iommu;
328 	unsigned long flags;
329 
330 	/*
331 	 * At boot, we'll have a first call into .flush_iotlb_all right after
332 	 * .probe_device, and since we link our (single) domain to our iommu in
333 	 * the .attach_device callback, we don't have that pointer set.
334 	 *
335 	 * It shouldn't really be any trouble to ignore it though since we flush
336 	 * all caches as part of the device powerup.
337 	 */
338 	if (!iommu)
339 		return;
340 
341 	spin_lock_irqsave(&iommu->iommu_lock, flags);
342 	sun50i_iommu_flush_all_tlb(iommu);
343 	spin_unlock_irqrestore(&iommu->iommu_lock, flags);
344 }
345 
346 static void sun50i_iommu_iotlb_sync(struct iommu_domain *domain,
347 				    struct iommu_iotlb_gather *gather)
348 {
349 	sun50i_iommu_flush_iotlb_all(domain);
350 }
351 
352 static int sun50i_iommu_enable(struct sun50i_iommu *iommu)
353 {
354 	struct sun50i_iommu_domain *sun50i_domain;
355 	unsigned long flags;
356 	int ret;
357 
358 	if (!iommu->domain)
359 		return 0;
360 
361 	sun50i_domain = to_sun50i_domain(iommu->domain);
362 
363 	ret = reset_control_deassert(iommu->reset);
364 	if (ret)
365 		return ret;
366 
367 	ret = clk_prepare_enable(iommu->clk);
368 	if (ret)
369 		goto err_reset_assert;
370 
371 	spin_lock_irqsave(&iommu->iommu_lock, flags);
372 
373 	iommu_write(iommu, IOMMU_TTB_REG, sun50i_domain->dt_dma);
374 	iommu_write(iommu, IOMMU_TLB_PREFETCH_REG,
375 		    IOMMU_TLB_PREFETCH_MASTER_ENABLE(0) |
376 		    IOMMU_TLB_PREFETCH_MASTER_ENABLE(1) |
377 		    IOMMU_TLB_PREFETCH_MASTER_ENABLE(2) |
378 		    IOMMU_TLB_PREFETCH_MASTER_ENABLE(3) |
379 		    IOMMU_TLB_PREFETCH_MASTER_ENABLE(4) |
380 		    IOMMU_TLB_PREFETCH_MASTER_ENABLE(5));
381 	iommu_write(iommu, IOMMU_INT_ENABLE_REG, IOMMU_INT_MASK);
382 	iommu_write(iommu, IOMMU_DM_AUT_CTRL_REG(SUN50I_IOMMU_ACI_NONE),
383 		    IOMMU_DM_AUT_CTRL_RD_UNAVAIL(SUN50I_IOMMU_ACI_NONE, 0) |
384 		    IOMMU_DM_AUT_CTRL_WR_UNAVAIL(SUN50I_IOMMU_ACI_NONE, 0) |
385 		    IOMMU_DM_AUT_CTRL_RD_UNAVAIL(SUN50I_IOMMU_ACI_NONE, 1) |
386 		    IOMMU_DM_AUT_CTRL_WR_UNAVAIL(SUN50I_IOMMU_ACI_NONE, 1) |
387 		    IOMMU_DM_AUT_CTRL_RD_UNAVAIL(SUN50I_IOMMU_ACI_NONE, 2) |
388 		    IOMMU_DM_AUT_CTRL_WR_UNAVAIL(SUN50I_IOMMU_ACI_NONE, 2) |
389 		    IOMMU_DM_AUT_CTRL_RD_UNAVAIL(SUN50I_IOMMU_ACI_NONE, 3) |
390 		    IOMMU_DM_AUT_CTRL_WR_UNAVAIL(SUN50I_IOMMU_ACI_NONE, 3) |
391 		    IOMMU_DM_AUT_CTRL_RD_UNAVAIL(SUN50I_IOMMU_ACI_NONE, 4) |
392 		    IOMMU_DM_AUT_CTRL_WR_UNAVAIL(SUN50I_IOMMU_ACI_NONE, 4) |
393 		    IOMMU_DM_AUT_CTRL_RD_UNAVAIL(SUN50I_IOMMU_ACI_NONE, 5) |
394 		    IOMMU_DM_AUT_CTRL_WR_UNAVAIL(SUN50I_IOMMU_ACI_NONE, 5));
395 
396 	iommu_write(iommu, IOMMU_DM_AUT_CTRL_REG(SUN50I_IOMMU_ACI_RD),
397 		    IOMMU_DM_AUT_CTRL_WR_UNAVAIL(SUN50I_IOMMU_ACI_RD, 0) |
398 		    IOMMU_DM_AUT_CTRL_WR_UNAVAIL(SUN50I_IOMMU_ACI_RD, 1) |
399 		    IOMMU_DM_AUT_CTRL_WR_UNAVAIL(SUN50I_IOMMU_ACI_RD, 2) |
400 		    IOMMU_DM_AUT_CTRL_WR_UNAVAIL(SUN50I_IOMMU_ACI_RD, 3) |
401 		    IOMMU_DM_AUT_CTRL_WR_UNAVAIL(SUN50I_IOMMU_ACI_RD, 4) |
402 		    IOMMU_DM_AUT_CTRL_WR_UNAVAIL(SUN50I_IOMMU_ACI_RD, 5));
403 
404 	iommu_write(iommu, IOMMU_DM_AUT_CTRL_REG(SUN50I_IOMMU_ACI_WR),
405 		    IOMMU_DM_AUT_CTRL_RD_UNAVAIL(SUN50I_IOMMU_ACI_WR, 0) |
406 		    IOMMU_DM_AUT_CTRL_RD_UNAVAIL(SUN50I_IOMMU_ACI_WR, 1) |
407 		    IOMMU_DM_AUT_CTRL_RD_UNAVAIL(SUN50I_IOMMU_ACI_WR, 2) |
408 		    IOMMU_DM_AUT_CTRL_RD_UNAVAIL(SUN50I_IOMMU_ACI_WR, 3) |
409 		    IOMMU_DM_AUT_CTRL_RD_UNAVAIL(SUN50I_IOMMU_ACI_WR, 4) |
410 		    IOMMU_DM_AUT_CTRL_RD_UNAVAIL(SUN50I_IOMMU_ACI_WR, 5));
411 
412 	ret = sun50i_iommu_flush_all_tlb(iommu);
413 	if (ret) {
414 		spin_unlock_irqrestore(&iommu->iommu_lock, flags);
415 		goto err_clk_disable;
416 	}
417 
418 	iommu_write(iommu, IOMMU_AUTO_GATING_REG, IOMMU_AUTO_GATING_ENABLE);
419 	iommu_write(iommu, IOMMU_ENABLE_REG, IOMMU_ENABLE_ENABLE);
420 
421 	spin_unlock_irqrestore(&iommu->iommu_lock, flags);
422 
423 	return 0;
424 
425 err_clk_disable:
426 	clk_disable_unprepare(iommu->clk);
427 
428 err_reset_assert:
429 	reset_control_assert(iommu->reset);
430 
431 	return ret;
432 }
433 
434 static void sun50i_iommu_disable(struct sun50i_iommu *iommu)
435 {
436 	unsigned long flags;
437 
438 	spin_lock_irqsave(&iommu->iommu_lock, flags);
439 
440 	iommu_write(iommu, IOMMU_ENABLE_REG, 0);
441 	iommu_write(iommu, IOMMU_TTB_REG, 0);
442 
443 	spin_unlock_irqrestore(&iommu->iommu_lock, flags);
444 
445 	clk_disable_unprepare(iommu->clk);
446 	reset_control_assert(iommu->reset);
447 }
448 
449 static void *sun50i_iommu_alloc_page_table(struct sun50i_iommu *iommu,
450 					   gfp_t gfp)
451 {
452 	dma_addr_t pt_dma;
453 	u32 *page_table;
454 
455 	page_table = kmem_cache_zalloc(iommu->pt_pool, gfp);
456 	if (!page_table)
457 		return ERR_PTR(-ENOMEM);
458 
459 	pt_dma = dma_map_single(iommu->dev, page_table, PT_SIZE, DMA_TO_DEVICE);
460 	if (dma_mapping_error(iommu->dev, pt_dma)) {
461 		dev_err(iommu->dev, "Couldn't map L2 Page Table\n");
462 		kmem_cache_free(iommu->pt_pool, page_table);
463 		return ERR_PTR(-ENOMEM);
464 	}
465 
466 	/* We rely on the physical address and DMA address being the same */
467 	WARN_ON(pt_dma != virt_to_phys(page_table));
468 
469 	return page_table;
470 }
471 
472 static void sun50i_iommu_free_page_table(struct sun50i_iommu *iommu,
473 					 u32 *page_table)
474 {
475 	phys_addr_t pt_phys = virt_to_phys(page_table);
476 
477 	dma_unmap_single(iommu->dev, pt_phys, PT_SIZE, DMA_TO_DEVICE);
478 	kmem_cache_free(iommu->pt_pool, page_table);
479 }
480 
481 static u32 *sun50i_dte_get_page_table(struct sun50i_iommu_domain *sun50i_domain,
482 				      dma_addr_t iova, gfp_t gfp)
483 {
484 	struct sun50i_iommu *iommu = sun50i_domain->iommu;
485 	u32 *page_table;
486 	u32 *dte_addr;
487 	u32 old_dte;
488 	u32 dte;
489 
490 	dte_addr = &sun50i_domain->dt[sun50i_iova_get_dte_index(iova)];
491 	dte = *dte_addr;
492 	if (sun50i_dte_is_pt_valid(dte)) {
493 		phys_addr_t pt_phys = sun50i_dte_get_pt_address(dte);
494 		return (u32 *)phys_to_virt(pt_phys);
495 	}
496 
497 	page_table = sun50i_iommu_alloc_page_table(iommu, gfp);
498 	if (IS_ERR(page_table))
499 		return page_table;
500 
501 	dte = sun50i_mk_dte(virt_to_phys(page_table));
502 	old_dte = cmpxchg(dte_addr, 0, dte);
503 	if (old_dte) {
504 		phys_addr_t installed_pt_phys =
505 			sun50i_dte_get_pt_address(old_dte);
506 		u32 *installed_pt = phys_to_virt(installed_pt_phys);
507 		u32 *drop_pt = page_table;
508 
509 		page_table = installed_pt;
510 		dte = old_dte;
511 		sun50i_iommu_free_page_table(iommu, drop_pt);
512 	}
513 
514 	sun50i_table_flush(sun50i_domain, page_table, PT_SIZE);
515 	sun50i_table_flush(sun50i_domain, dte_addr, 1);
516 
517 	return page_table;
518 }
519 
520 static int sun50i_iommu_map(struct iommu_domain *domain, unsigned long iova,
521 			    phys_addr_t paddr, size_t size, int prot, gfp_t gfp)
522 {
523 	struct sun50i_iommu_domain *sun50i_domain = to_sun50i_domain(domain);
524 	struct sun50i_iommu *iommu = sun50i_domain->iommu;
525 	u32 pte_index;
526 	u32 *page_table, *pte_addr;
527 	int ret = 0;
528 
529 	page_table = sun50i_dte_get_page_table(sun50i_domain, iova, gfp);
530 	if (IS_ERR(page_table)) {
531 		ret = PTR_ERR(page_table);
532 		goto out;
533 	}
534 
535 	pte_index = sun50i_iova_get_pte_index(iova);
536 	pte_addr = &page_table[pte_index];
537 	if (unlikely(sun50i_pte_is_page_valid(*pte_addr))) {
538 		phys_addr_t page_phys = sun50i_pte_get_page_address(*pte_addr);
539 		dev_err(iommu->dev,
540 			"iova %pad already mapped to %pa cannot remap to %pa prot: %#x\n",
541 			&iova, &page_phys, &paddr, prot);
542 		ret = -EBUSY;
543 		goto out;
544 	}
545 
546 	*pte_addr = sun50i_mk_pte(paddr, prot);
547 	sun50i_table_flush(sun50i_domain, pte_addr, 1);
548 
549 out:
550 	return ret;
551 }
552 
553 static size_t sun50i_iommu_unmap(struct iommu_domain *domain, unsigned long iova,
554 				 size_t size, struct iommu_iotlb_gather *gather)
555 {
556 	struct sun50i_iommu_domain *sun50i_domain = to_sun50i_domain(domain);
557 	phys_addr_t pt_phys;
558 	u32 *pte_addr;
559 	u32 dte;
560 
561 	dte = sun50i_domain->dt[sun50i_iova_get_dte_index(iova)];
562 	if (!sun50i_dte_is_pt_valid(dte))
563 		return 0;
564 
565 	pt_phys = sun50i_dte_get_pt_address(dte);
566 	pte_addr = (u32 *)phys_to_virt(pt_phys) + sun50i_iova_get_pte_index(iova);
567 
568 	if (!sun50i_pte_is_page_valid(*pte_addr))
569 		return 0;
570 
571 	memset(pte_addr, 0, sizeof(*pte_addr));
572 	sun50i_table_flush(sun50i_domain, pte_addr, 1);
573 
574 	return SZ_4K;
575 }
576 
577 static phys_addr_t sun50i_iommu_iova_to_phys(struct iommu_domain *domain,
578 					     dma_addr_t iova)
579 {
580 	struct sun50i_iommu_domain *sun50i_domain = to_sun50i_domain(domain);
581 	phys_addr_t pt_phys;
582 	u32 *page_table;
583 	u32 dte, pte;
584 
585 	dte = sun50i_domain->dt[sun50i_iova_get_dte_index(iova)];
586 	if (!sun50i_dte_is_pt_valid(dte))
587 		return 0;
588 
589 	pt_phys = sun50i_dte_get_pt_address(dte);
590 	page_table = (u32 *)phys_to_virt(pt_phys);
591 	pte = page_table[sun50i_iova_get_pte_index(iova)];
592 	if (!sun50i_pte_is_page_valid(pte))
593 		return 0;
594 
595 	return sun50i_pte_get_page_address(pte) +
596 		sun50i_iova_get_page_offset(iova);
597 }
598 
599 static struct iommu_domain *sun50i_iommu_domain_alloc(unsigned type)
600 {
601 	struct sun50i_iommu_domain *sun50i_domain;
602 
603 	if (type != IOMMU_DOMAIN_DMA &&
604 	    type != IOMMU_DOMAIN_IDENTITY &&
605 	    type != IOMMU_DOMAIN_UNMANAGED)
606 		return NULL;
607 
608 	sun50i_domain = kzalloc(sizeof(*sun50i_domain), GFP_KERNEL);
609 	if (!sun50i_domain)
610 		return NULL;
611 
612 	sun50i_domain->dt = (u32 *)__get_free_pages(GFP_KERNEL | __GFP_ZERO,
613 						    get_order(DT_SIZE));
614 	if (!sun50i_domain->dt)
615 		goto err_free_domain;
616 
617 	refcount_set(&sun50i_domain->refcnt, 1);
618 
619 	sun50i_domain->domain.geometry.aperture_start = 0;
620 	sun50i_domain->domain.geometry.aperture_end = DMA_BIT_MASK(32);
621 	sun50i_domain->domain.geometry.force_aperture = true;
622 
623 	return &sun50i_domain->domain;
624 
625 err_free_domain:
626 	kfree(sun50i_domain);
627 
628 	return NULL;
629 }
630 
631 static void sun50i_iommu_domain_free(struct iommu_domain *domain)
632 {
633 	struct sun50i_iommu_domain *sun50i_domain = to_sun50i_domain(domain);
634 
635 	free_pages((unsigned long)sun50i_domain->dt, get_order(DT_SIZE));
636 	sun50i_domain->dt = NULL;
637 
638 	kfree(sun50i_domain);
639 }
640 
641 static int sun50i_iommu_attach_domain(struct sun50i_iommu *iommu,
642 				      struct sun50i_iommu_domain *sun50i_domain)
643 {
644 	iommu->domain = &sun50i_domain->domain;
645 	sun50i_domain->iommu = iommu;
646 
647 	sun50i_domain->dt_dma = dma_map_single(iommu->dev, sun50i_domain->dt,
648 					       DT_SIZE, DMA_TO_DEVICE);
649 	if (dma_mapping_error(iommu->dev, sun50i_domain->dt_dma)) {
650 		dev_err(iommu->dev, "Couldn't map L1 Page Table\n");
651 		return -ENOMEM;
652 	}
653 
654 	return sun50i_iommu_enable(iommu);
655 }
656 
657 static void sun50i_iommu_detach_domain(struct sun50i_iommu *iommu,
658 				       struct sun50i_iommu_domain *sun50i_domain)
659 {
660 	unsigned int i;
661 
662 	for (i = 0; i < NUM_DT_ENTRIES; i++) {
663 		phys_addr_t pt_phys;
664 		u32 *page_table;
665 		u32 *dte_addr;
666 		u32 dte;
667 
668 		dte_addr = &sun50i_domain->dt[i];
669 		dte = *dte_addr;
670 		if (!sun50i_dte_is_pt_valid(dte))
671 			continue;
672 
673 		memset(dte_addr, 0, sizeof(*dte_addr));
674 		sun50i_table_flush(sun50i_domain, dte_addr, 1);
675 
676 		pt_phys = sun50i_dte_get_pt_address(dte);
677 		page_table = phys_to_virt(pt_phys);
678 		sun50i_iommu_free_page_table(iommu, page_table);
679 	}
680 
681 
682 	sun50i_iommu_disable(iommu);
683 
684 	dma_unmap_single(iommu->dev, virt_to_phys(sun50i_domain->dt),
685 			 DT_SIZE, DMA_TO_DEVICE);
686 
687 	iommu->domain = NULL;
688 }
689 
690 static void sun50i_iommu_detach_device(struct iommu_domain *domain,
691 				       struct device *dev)
692 {
693 	struct sun50i_iommu_domain *sun50i_domain = to_sun50i_domain(domain);
694 	struct sun50i_iommu *iommu = dev_iommu_priv_get(dev);
695 
696 	dev_dbg(dev, "Detaching from IOMMU domain\n");
697 
698 	if (iommu->domain != domain)
699 		return;
700 
701 	if (refcount_dec_and_test(&sun50i_domain->refcnt))
702 		sun50i_iommu_detach_domain(iommu, sun50i_domain);
703 }
704 
705 static int sun50i_iommu_attach_device(struct iommu_domain *domain,
706 				      struct device *dev)
707 {
708 	struct sun50i_iommu_domain *sun50i_domain = to_sun50i_domain(domain);
709 	struct sun50i_iommu *iommu;
710 
711 	iommu = sun50i_iommu_from_dev(dev);
712 	if (!iommu)
713 		return -ENODEV;
714 
715 	dev_dbg(dev, "Attaching to IOMMU domain\n");
716 
717 	refcount_inc(&sun50i_domain->refcnt);
718 
719 	if (iommu->domain == domain)
720 		return 0;
721 
722 	if (iommu->domain)
723 		sun50i_iommu_detach_device(iommu->domain, dev);
724 
725 	sun50i_iommu_attach_domain(iommu, sun50i_domain);
726 
727 	return 0;
728 }
729 
730 static struct iommu_device *sun50i_iommu_probe_device(struct device *dev)
731 {
732 	struct sun50i_iommu *iommu;
733 
734 	iommu = sun50i_iommu_from_dev(dev);
735 	if (!iommu)
736 		return ERR_PTR(-ENODEV);
737 
738 	return &iommu->iommu;
739 }
740 
741 static struct iommu_group *sun50i_iommu_device_group(struct device *dev)
742 {
743 	struct sun50i_iommu *iommu = sun50i_iommu_from_dev(dev);
744 
745 	return iommu_group_ref_get(iommu->group);
746 }
747 
748 static int sun50i_iommu_of_xlate(struct device *dev,
749 				 struct of_phandle_args *args)
750 {
751 	struct platform_device *iommu_pdev = of_find_device_by_node(args->np);
752 	unsigned id = args->args[0];
753 
754 	dev_iommu_priv_set(dev, platform_get_drvdata(iommu_pdev));
755 
756 	return iommu_fwspec_add_ids(dev, &id, 1);
757 }
758 
759 static const struct iommu_ops sun50i_iommu_ops = {
760 	.pgsize_bitmap	= SZ_4K,
761 	.device_group	= sun50i_iommu_device_group,
762 	.domain_alloc	= sun50i_iommu_domain_alloc,
763 	.of_xlate	= sun50i_iommu_of_xlate,
764 	.probe_device	= sun50i_iommu_probe_device,
765 	.default_domain_ops = &(const struct iommu_domain_ops) {
766 		.attach_dev	= sun50i_iommu_attach_device,
767 		.detach_dev	= sun50i_iommu_detach_device,
768 		.flush_iotlb_all = sun50i_iommu_flush_iotlb_all,
769 		.iotlb_sync	= sun50i_iommu_iotlb_sync,
770 		.iova_to_phys	= sun50i_iommu_iova_to_phys,
771 		.map		= sun50i_iommu_map,
772 		.unmap		= sun50i_iommu_unmap,
773 		.free		= sun50i_iommu_domain_free,
774 	}
775 };
776 
777 static void sun50i_iommu_report_fault(struct sun50i_iommu *iommu,
778 				      unsigned master, phys_addr_t iova,
779 				      unsigned prot)
780 {
781 	dev_err(iommu->dev, "Page fault for %pad (master %d, dir %s)\n",
782 		&iova, master, (prot == IOMMU_FAULT_WRITE) ? "wr" : "rd");
783 
784 	if (iommu->domain)
785 		report_iommu_fault(iommu->domain, iommu->dev, iova, prot);
786 	else
787 		dev_err(iommu->dev, "Page fault while iommu not attached to any domain?\n");
788 }
789 
790 static phys_addr_t sun50i_iommu_handle_pt_irq(struct sun50i_iommu *iommu,
791 					      unsigned addr_reg,
792 					      unsigned blame_reg)
793 {
794 	phys_addr_t iova;
795 	unsigned master;
796 	u32 blame;
797 
798 	assert_spin_locked(&iommu->iommu_lock);
799 
800 	iova = iommu_read(iommu, addr_reg);
801 	blame = iommu_read(iommu, blame_reg);
802 	master = ilog2(blame & IOMMU_INT_MASTER_MASK);
803 
804 	/*
805 	 * If the address is not in the page table, we can't get what
806 	 * operation triggered the fault. Assume it's a read
807 	 * operation.
808 	 */
809 	sun50i_iommu_report_fault(iommu, master, iova, IOMMU_FAULT_READ);
810 
811 	return iova;
812 }
813 
814 static phys_addr_t sun50i_iommu_handle_perm_irq(struct sun50i_iommu *iommu)
815 {
816 	enum sun50i_iommu_aci aci;
817 	phys_addr_t iova;
818 	unsigned master;
819 	unsigned dir;
820 	u32 blame;
821 
822 	assert_spin_locked(&iommu->iommu_lock);
823 
824 	blame = iommu_read(iommu, IOMMU_INT_STA_REG);
825 	master = ilog2(blame & IOMMU_INT_MASTER_MASK);
826 	iova = iommu_read(iommu, IOMMU_INT_ERR_ADDR_REG(master));
827 	aci = sun50i_get_pte_aci(iommu_read(iommu,
828 					    IOMMU_INT_ERR_DATA_REG(master)));
829 
830 	switch (aci) {
831 		/*
832 		 * If we are in the read-only domain, then it means we
833 		 * tried to write.
834 		 */
835 	case SUN50I_IOMMU_ACI_RD:
836 		dir = IOMMU_FAULT_WRITE;
837 		break;
838 
839 		/*
840 		 * If we are in the write-only domain, then it means
841 		 * we tried to read.
842 		 */
843 	case SUN50I_IOMMU_ACI_WR:
844 
845 		/*
846 		 * If we are in the domain without any permission, we
847 		 * can't really tell. Let's default to a read
848 		 * operation.
849 		 */
850 	case SUN50I_IOMMU_ACI_NONE:
851 
852 		/* WTF? */
853 	case SUN50I_IOMMU_ACI_RD_WR:
854 	default:
855 		dir = IOMMU_FAULT_READ;
856 		break;
857 	}
858 
859 	/*
860 	 * If the address is not in the page table, we can't get what
861 	 * operation triggered the fault. Assume it's a read
862 	 * operation.
863 	 */
864 	sun50i_iommu_report_fault(iommu, master, iova, dir);
865 
866 	return iova;
867 }
868 
869 static irqreturn_t sun50i_iommu_irq(int irq, void *dev_id)
870 {
871 	struct sun50i_iommu *iommu = dev_id;
872 	u32 status;
873 
874 	spin_lock(&iommu->iommu_lock);
875 
876 	status = iommu_read(iommu, IOMMU_INT_STA_REG);
877 	if (!(status & IOMMU_INT_MASK)) {
878 		spin_unlock(&iommu->iommu_lock);
879 		return IRQ_NONE;
880 	}
881 
882 	if (status & IOMMU_INT_INVALID_L2PG)
883 		sun50i_iommu_handle_pt_irq(iommu,
884 					    IOMMU_INT_ERR_ADDR_L2_REG,
885 					    IOMMU_L2PG_INT_REG);
886 	else if (status & IOMMU_INT_INVALID_L1PG)
887 		sun50i_iommu_handle_pt_irq(iommu,
888 					   IOMMU_INT_ERR_ADDR_L1_REG,
889 					   IOMMU_L1PG_INT_REG);
890 	else
891 		sun50i_iommu_handle_perm_irq(iommu);
892 
893 	iommu_write(iommu, IOMMU_INT_CLR_REG, status);
894 
895 	iommu_write(iommu, IOMMU_RESET_REG, ~status);
896 	iommu_write(iommu, IOMMU_RESET_REG, status);
897 
898 	spin_unlock(&iommu->iommu_lock);
899 
900 	return IRQ_HANDLED;
901 }
902 
903 static int sun50i_iommu_probe(struct platform_device *pdev)
904 {
905 	struct sun50i_iommu *iommu;
906 	int ret, irq;
907 
908 	iommu = devm_kzalloc(&pdev->dev, sizeof(*iommu), GFP_KERNEL);
909 	if (!iommu)
910 		return -ENOMEM;
911 	spin_lock_init(&iommu->iommu_lock);
912 	platform_set_drvdata(pdev, iommu);
913 	iommu->dev = &pdev->dev;
914 
915 	iommu->pt_pool = kmem_cache_create(dev_name(&pdev->dev),
916 					   PT_SIZE, PT_SIZE,
917 					   SLAB_HWCACHE_ALIGN,
918 					   NULL);
919 	if (!iommu->pt_pool)
920 		return -ENOMEM;
921 
922 	iommu->group = iommu_group_alloc();
923 	if (IS_ERR(iommu->group)) {
924 		ret = PTR_ERR(iommu->group);
925 		goto err_free_cache;
926 	}
927 
928 	iommu->base = devm_platform_ioremap_resource(pdev, 0);
929 	if (IS_ERR(iommu->base)) {
930 		ret = PTR_ERR(iommu->base);
931 		goto err_free_group;
932 	}
933 
934 	irq = platform_get_irq(pdev, 0);
935 	if (irq < 0) {
936 		ret = irq;
937 		goto err_free_group;
938 	}
939 
940 	iommu->clk = devm_clk_get(&pdev->dev, NULL);
941 	if (IS_ERR(iommu->clk)) {
942 		dev_err(&pdev->dev, "Couldn't get our clock.\n");
943 		ret = PTR_ERR(iommu->clk);
944 		goto err_free_group;
945 	}
946 
947 	iommu->reset = devm_reset_control_get(&pdev->dev, NULL);
948 	if (IS_ERR(iommu->reset)) {
949 		dev_err(&pdev->dev, "Couldn't get our reset line.\n");
950 		ret = PTR_ERR(iommu->reset);
951 		goto err_free_group;
952 	}
953 
954 	ret = iommu_device_sysfs_add(&iommu->iommu, &pdev->dev,
955 				     NULL, dev_name(&pdev->dev));
956 	if (ret)
957 		goto err_free_group;
958 
959 	ret = iommu_device_register(&iommu->iommu, &sun50i_iommu_ops, &pdev->dev);
960 	if (ret)
961 		goto err_remove_sysfs;
962 
963 	ret = devm_request_irq(&pdev->dev, irq, sun50i_iommu_irq, 0,
964 			       dev_name(&pdev->dev), iommu);
965 	if (ret < 0)
966 		goto err_unregister;
967 
968 	return 0;
969 
970 err_unregister:
971 	iommu_device_unregister(&iommu->iommu);
972 
973 err_remove_sysfs:
974 	iommu_device_sysfs_remove(&iommu->iommu);
975 
976 err_free_group:
977 	iommu_group_put(iommu->group);
978 
979 err_free_cache:
980 	kmem_cache_destroy(iommu->pt_pool);
981 
982 	return ret;
983 }
984 
985 static const struct of_device_id sun50i_iommu_dt[] = {
986 	{ .compatible = "allwinner,sun50i-h6-iommu", },
987 	{ /* sentinel */ },
988 };
989 MODULE_DEVICE_TABLE(of, sun50i_iommu_dt);
990 
991 static struct platform_driver sun50i_iommu_driver = {
992 	.driver		= {
993 		.name			= "sun50i-iommu",
994 		.of_match_table 	= sun50i_iommu_dt,
995 		.suppress_bind_attrs	= true,
996 	}
997 };
998 builtin_platform_driver_probe(sun50i_iommu_driver, sun50i_iommu_probe);
999 
1000 MODULE_DESCRIPTION("Allwinner H6 IOMMU driver");
1001 MODULE_AUTHOR("Maxime Ripard <maxime@cerno.tech>");
1002 MODULE_AUTHOR("zhuxianbin <zhuxianbin@allwinnertech.com>");
1003 MODULE_LICENSE("Dual BSD/GPL");
1004