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-iommu.h>
11#include <linux/dma-mapping.h>
12#include <linux/err.h>
13#include <linux/errno.h>
14#include <linux/interrupt.h>
15#include <linux/iommu.h>
16#include <linux/iopoll.h>
17#include <linux/ioport.h>
18#include <linux/log2.h>
19#include <linux/module.h>
20#include <linux/of_platform.h>
21#include <linux/platform_device.h>
22#include <linux/pm.h>
23#include <linux/pm_runtime.h>
24#include <linux/reset.h>
25#include <linux/sizes.h>
26#include <linux/slab.h>
27#include <linux/spinlock.h>
28#include <linux/types.h>
29
30#define IOMMU_RESET_REG			0x010
31#define IOMMU_RESET_RELEASE_ALL			0xffffffff
32#define IOMMU_ENABLE_REG		0x020
33#define IOMMU_ENABLE_ENABLE			BIT(0)
34
35#define IOMMU_BYPASS_REG		0x030
36#define IOMMU_AUTO_GATING_REG		0x040
37#define IOMMU_AUTO_GATING_ENABLE		BIT(0)
38
39#define IOMMU_WBUF_CTRL_REG		0x044
40#define IOMMU_OOO_CTRL_REG		0x048
41#define IOMMU_4KB_BDY_PRT_CTRL_REG	0x04c
42#define IOMMU_TTB_REG			0x050
43#define IOMMU_TLB_ENABLE_REG		0x060
44#define IOMMU_TLB_PREFETCH_REG		0x070
45#define IOMMU_TLB_PREFETCH_MASTER_ENABLE(m)	BIT(m)
46
47#define IOMMU_TLB_FLUSH_REG		0x080
48#define IOMMU_TLB_FLUSH_PTW_CACHE		BIT(17)
49#define IOMMU_TLB_FLUSH_MACRO_TLB		BIT(16)
50#define IOMMU_TLB_FLUSH_MICRO_TLB(i)		(BIT(i) & GENMASK(5, 0))
51
52#define IOMMU_TLB_IVLD_ADDR_REG		0x090
53#define IOMMU_TLB_IVLD_ADDR_MASK_REG	0x094
54#define IOMMU_TLB_IVLD_ENABLE_REG	0x098
55#define IOMMU_TLB_IVLD_ENABLE_ENABLE		BIT(0)
56
57#define IOMMU_PC_IVLD_ADDR_REG		0x0a0
58#define IOMMU_PC_IVLD_ENABLE_REG	0x0a8
59#define IOMMU_PC_IVLD_ENABLE_ENABLE		BIT(0)
60
61#define IOMMU_DM_AUT_CTRL_REG(d)	(0x0b0 + ((d) / 2) * 4)
62#define IOMMU_DM_AUT_CTRL_RD_UNAVAIL(d, m)	(1 << (((d & 1) * 16) + ((m) * 2)))
63#define IOMMU_DM_AUT_CTRL_WR_UNAVAIL(d, m)	(1 << (((d & 1) * 16) + ((m) * 2) + 1))
64
65#define IOMMU_DM_AUT_OVWT_REG		0x0d0
66#define IOMMU_INT_ENABLE_REG		0x100
67#define IOMMU_INT_CLR_REG		0x104
68#define IOMMU_INT_STA_REG		0x108
69#define IOMMU_INT_ERR_ADDR_REG(i)	(0x110 + (i) * 4)
70#define IOMMU_INT_ERR_ADDR_L1_REG	0x130
71#define IOMMU_INT_ERR_ADDR_L2_REG	0x134
72#define IOMMU_INT_ERR_DATA_REG(i)	(0x150 + (i) * 4)
73#define IOMMU_L1PG_INT_REG		0x0180
74#define IOMMU_L2PG_INT_REG		0x0184
75
76#define IOMMU_INT_INVALID_L2PG			BIT(17)
77#define IOMMU_INT_INVALID_L1PG			BIT(16)
78#define IOMMU_INT_MASTER_PERMISSION(m)		BIT(m)
79#define IOMMU_INT_MASTER_MASK			(IOMMU_INT_MASTER_PERMISSION(0) | \
80						 IOMMU_INT_MASTER_PERMISSION(1) | \
81						 IOMMU_INT_MASTER_PERMISSION(2) | \
82						 IOMMU_INT_MASTER_PERMISSION(3) | \
83						 IOMMU_INT_MASTER_PERMISSION(4) | \
84						 IOMMU_INT_MASTER_PERMISSION(5))
85#define IOMMU_INT_MASK				(IOMMU_INT_INVALID_L1PG | \
86						 IOMMU_INT_INVALID_L2PG | \
87						 IOMMU_INT_MASTER_MASK)
88
89#define PT_ENTRY_SIZE			sizeof(u32)
90
91#define NUM_DT_ENTRIES			4096
92#define DT_SIZE				(NUM_DT_ENTRIES * PT_ENTRY_SIZE)
93
94#define NUM_PT_ENTRIES			256
95#define PT_SIZE				(NUM_PT_ENTRIES * PT_ENTRY_SIZE)
96
97struct sun50i_iommu {
98	struct iommu_device iommu;
99
100	/* Lock to modify the IOMMU registers */
101	spinlock_t iommu_lock;
102
103	struct device *dev;
104	void __iomem *base;
105	struct reset_control *reset;
106	struct clk *clk;
107
108	struct iommu_domain *domain;
109	struct iommu_group *group;
110	struct kmem_cache *pt_pool;
111};
112
113struct sun50i_iommu_domain {
114	struct iommu_domain domain;
115
116	/* Number of devices attached to the domain */
117	refcount_t refcnt;
118
119	/* L1 Page Table */
120	u32 *dt;
121	dma_addr_t dt_dma;
122
123	struct sun50i_iommu *iommu;
124};
125
126static struct sun50i_iommu_domain *to_sun50i_domain(struct iommu_domain *domain)
127{
128	return container_of(domain, struct sun50i_iommu_domain, domain);
129}
130
131static struct sun50i_iommu *sun50i_iommu_from_dev(struct device *dev)
132{
133	return dev_iommu_priv_get(dev);
134}
135
136static u32 iommu_read(struct sun50i_iommu *iommu, u32 offset)
137{
138	return readl(iommu->base + offset);
139}
140
141static void iommu_write(struct sun50i_iommu *iommu, u32 offset, u32 value)
142{
143	writel(value, iommu->base + offset);
144}
145
146/*
147 * The Allwinner H6 IOMMU uses a 2-level page table.
148 *
149 * The first level is the usual Directory Table (DT), that consists of
150 * 4096 4-bytes Directory Table Entries (DTE), each pointing to a Page
151 * Table (PT).
152 *
153 * Each PT consits of 256 4-bytes Page Table Entries (PTE), each
154 * pointing to a 4kB page of physical memory.
155 *
156 * The IOMMU supports a single DT, pointed by the IOMMU_TTB_REG
157 * register that contains its physical address.
158 */
159
160#define SUN50I_IOVA_DTE_MASK	GENMASK(31, 20)
161#define SUN50I_IOVA_PTE_MASK	GENMASK(19, 12)
162#define SUN50I_IOVA_PAGE_MASK	GENMASK(11, 0)
163
164static u32 sun50i_iova_get_dte_index(dma_addr_t iova)
165{
166	return FIELD_GET(SUN50I_IOVA_DTE_MASK, iova);
167}
168
169static u32 sun50i_iova_get_pte_index(dma_addr_t iova)
170{
171	return FIELD_GET(SUN50I_IOVA_PTE_MASK, iova);
172}
173
174static u32 sun50i_iova_get_page_offset(dma_addr_t iova)
175{
176	return FIELD_GET(SUN50I_IOVA_PAGE_MASK, iova);
177}
178
179/*
180 * Each Directory Table Entry has a Page Table address and a valid
181 * bit:
182
183 * +---------------------+-----------+-+
184 * | PT address          | Reserved  |V|
185 * +---------------------+-----------+-+
186 *  31:10 - Page Table address
187 *   9:2  - Reserved
188 *   1:0  - 1 if the entry is valid
189 */
190
191#define SUN50I_DTE_PT_ADDRESS_MASK	GENMASK(31, 10)
192#define SUN50I_DTE_PT_ATTRS		GENMASK(1, 0)
193#define SUN50I_DTE_PT_VALID		1
194
195static phys_addr_t sun50i_dte_get_pt_address(u32 dte)
196{
197	return (phys_addr_t)dte & SUN50I_DTE_PT_ADDRESS_MASK;
198}
199
200static bool sun50i_dte_is_pt_valid(u32 dte)
201{
202	return (dte & SUN50I_DTE_PT_ATTRS) == SUN50I_DTE_PT_VALID;
203}
204
205static u32 sun50i_mk_dte(dma_addr_t pt_dma)
206{
207	return (pt_dma & SUN50I_DTE_PT_ADDRESS_MASK) | SUN50I_DTE_PT_VALID;
208}
209
210/*
211 * Each PTE has a Page address, an authority index and a valid bit:
212 *
213 * +----------------+-----+-----+-----+---+-----+
214 * | Page address   | Rsv | ACI | Rsv | V | Rsv |
215 * +----------------+-----+-----+-----+---+-----+
216 *  31:12 - Page address
217 *  11:8  - Reserved
218 *   7:4  - Authority Control Index
219 *   3:2  - Reserved
220 *     1  - 1 if the entry is valid
221 *     0  - Reserved
222 *
223 * The way permissions work is that the IOMMU has 16 "domains" that
224 * can be configured to give each masters either read or write
225 * permissions through the IOMMU_DM_AUT_CTRL_REG registers. The domain
226 * 0 seems like the default domain, and its permissions in the
227 * IOMMU_DM_AUT_CTRL_REG are only read-only, so it's not really
228 * useful to enforce any particular permission.
229 *
230 * Each page entry will then have a reference to the domain they are
231 * affected to, so that we can actually enforce them on a per-page
232 * basis.
233 *
234 * In order to make it work with the IOMMU framework, we will be using
235 * 4 different domains, starting at 1: RD_WR, RD, WR and NONE
236 * depending on the permission we want to enforce. Each domain will
237 * have each master setup in the same way, since the IOMMU framework
238 * doesn't seem to restrict page access on a per-device basis. And
239 * then we will use the relevant domain index when generating the page
240 * table entry depending on the permissions we want to be enforced.
241 */
242
243enum sun50i_iommu_aci {
244	SUN50I_IOMMU_ACI_DO_NOT_USE = 0,
245	SUN50I_IOMMU_ACI_NONE,
246	SUN50I_IOMMU_ACI_RD,
247	SUN50I_IOMMU_ACI_WR,
248	SUN50I_IOMMU_ACI_RD_WR,
249};
250
251#define SUN50I_PTE_PAGE_ADDRESS_MASK	GENMASK(31, 12)
252#define SUN50I_PTE_ACI_MASK		GENMASK(7, 4)
253#define SUN50I_PTE_PAGE_VALID		BIT(1)
254
255static phys_addr_t sun50i_pte_get_page_address(u32 pte)
256{
257	return (phys_addr_t)pte & SUN50I_PTE_PAGE_ADDRESS_MASK;
258}
259
260static enum sun50i_iommu_aci sun50i_get_pte_aci(u32 pte)
261{
262	return FIELD_GET(SUN50I_PTE_ACI_MASK, pte);
263}
264
265static bool sun50i_pte_is_page_valid(u32 pte)
266{
267	return pte & SUN50I_PTE_PAGE_VALID;
268}
269
270static u32 sun50i_mk_pte(phys_addr_t page, int prot)
271{
272	enum sun50i_iommu_aci aci;
273	u32 flags = 0;
274
275	if ((prot & (IOMMU_READ | IOMMU_WRITE)) == (IOMMU_READ | IOMMU_WRITE))
276		aci = SUN50I_IOMMU_ACI_RD_WR;
277	else if (prot & IOMMU_READ)
278		aci = SUN50I_IOMMU_ACI_RD;
279	else if (prot & IOMMU_WRITE)
280		aci = SUN50I_IOMMU_ACI_WR;
281	else
282		aci = SUN50I_IOMMU_ACI_NONE;
283
284	flags |= FIELD_PREP(SUN50I_PTE_ACI_MASK, aci);
285	page &= SUN50I_PTE_PAGE_ADDRESS_MASK;
286	return page | flags | SUN50I_PTE_PAGE_VALID;
287}
288
289static void sun50i_table_flush(struct sun50i_iommu_domain *sun50i_domain,
290			       void *vaddr, unsigned int count)
291{
292	struct sun50i_iommu *iommu = sun50i_domain->iommu;
293	dma_addr_t dma = virt_to_phys(vaddr);
294	size_t size = count * PT_ENTRY_SIZE;
295
296	dma_sync_single_for_device(iommu->dev, dma, size, DMA_TO_DEVICE);
297}
298
299static int sun50i_iommu_flush_all_tlb(struct sun50i_iommu *iommu)
300{
301	u32 reg;
302	int ret;
303
304	assert_spin_locked(&iommu->iommu_lock);
305
306	iommu_write(iommu,
307		    IOMMU_TLB_FLUSH_REG,
308		    IOMMU_TLB_FLUSH_PTW_CACHE |
309		    IOMMU_TLB_FLUSH_MACRO_TLB |
310		    IOMMU_TLB_FLUSH_MICRO_TLB(5) |
311		    IOMMU_TLB_FLUSH_MICRO_TLB(4) |
312		    IOMMU_TLB_FLUSH_MICRO_TLB(3) |
313		    IOMMU_TLB_FLUSH_MICRO_TLB(2) |
314		    IOMMU_TLB_FLUSH_MICRO_TLB(1) |
315		    IOMMU_TLB_FLUSH_MICRO_TLB(0));
316
317	ret = readl_poll_timeout_atomic(iommu->base + IOMMU_TLB_FLUSH_REG,
318					reg, !reg,
319					1, 2000);
320	if (ret)
321		dev_warn(iommu->dev, "TLB Flush timed out!\n");
322
323	return ret;
324}
325
326static void sun50i_iommu_flush_iotlb_all(struct iommu_domain *domain)
327{
328	struct sun50i_iommu_domain *sun50i_domain = to_sun50i_domain(domain);
329	struct sun50i_iommu *iommu = sun50i_domain->iommu;
330	unsigned long flags;
331
332	/*
333	 * At boot, we'll have a first call into .flush_iotlb_all right after
334	 * .probe_device, and since we link our (single) domain to our iommu in
335	 * the .attach_device callback, we don't have that pointer set.
336	 *
337	 * It shouldn't really be any trouble to ignore it though since we flush
338	 * all caches as part of the device powerup.
339	 */
340	if (!iommu)
341		return;
342
343	spin_lock_irqsave(&iommu->iommu_lock, flags);
344	sun50i_iommu_flush_all_tlb(iommu);
345	spin_unlock_irqrestore(&iommu->iommu_lock, flags);
346}
347
348static void sun50i_iommu_iotlb_sync(struct iommu_domain *domain,
349				    struct iommu_iotlb_gather *gather)
350{
351	sun50i_iommu_flush_iotlb_all(domain);
352}
353
354static int sun50i_iommu_enable(struct sun50i_iommu *iommu)
355{
356	struct sun50i_iommu_domain *sun50i_domain;
357	unsigned long flags;
358	int ret;
359
360	if (!iommu->domain)
361		return 0;
362
363	sun50i_domain = to_sun50i_domain(iommu->domain);
364
365	ret = reset_control_deassert(iommu->reset);
366	if (ret)
367		return ret;
368
369	ret = clk_prepare_enable(iommu->clk);
370	if (ret)
371		goto err_reset_assert;
372
373	spin_lock_irqsave(&iommu->iommu_lock, flags);
374
375	iommu_write(iommu, IOMMU_TTB_REG, sun50i_domain->dt_dma);
376	iommu_write(iommu, IOMMU_TLB_PREFETCH_REG,
377		    IOMMU_TLB_PREFETCH_MASTER_ENABLE(0) |
378		    IOMMU_TLB_PREFETCH_MASTER_ENABLE(1) |
379		    IOMMU_TLB_PREFETCH_MASTER_ENABLE(2) |
380		    IOMMU_TLB_PREFETCH_MASTER_ENABLE(3) |
381		    IOMMU_TLB_PREFETCH_MASTER_ENABLE(4) |
382		    IOMMU_TLB_PREFETCH_MASTER_ENABLE(5));
383	iommu_write(iommu, IOMMU_INT_ENABLE_REG, IOMMU_INT_MASK);
384	iommu_write(iommu, IOMMU_DM_AUT_CTRL_REG(SUN50I_IOMMU_ACI_NONE),
385		    IOMMU_DM_AUT_CTRL_RD_UNAVAIL(SUN50I_IOMMU_ACI_NONE, 0) |
386		    IOMMU_DM_AUT_CTRL_WR_UNAVAIL(SUN50I_IOMMU_ACI_NONE, 0) |
387		    IOMMU_DM_AUT_CTRL_RD_UNAVAIL(SUN50I_IOMMU_ACI_NONE, 1) |
388		    IOMMU_DM_AUT_CTRL_WR_UNAVAIL(SUN50I_IOMMU_ACI_NONE, 1) |
389		    IOMMU_DM_AUT_CTRL_RD_UNAVAIL(SUN50I_IOMMU_ACI_NONE, 2) |
390		    IOMMU_DM_AUT_CTRL_WR_UNAVAIL(SUN50I_IOMMU_ACI_NONE, 2) |
391		    IOMMU_DM_AUT_CTRL_RD_UNAVAIL(SUN50I_IOMMU_ACI_NONE, 3) |
392		    IOMMU_DM_AUT_CTRL_WR_UNAVAIL(SUN50I_IOMMU_ACI_NONE, 3) |
393		    IOMMU_DM_AUT_CTRL_RD_UNAVAIL(SUN50I_IOMMU_ACI_NONE, 4) |
394		    IOMMU_DM_AUT_CTRL_WR_UNAVAIL(SUN50I_IOMMU_ACI_NONE, 4) |
395		    IOMMU_DM_AUT_CTRL_RD_UNAVAIL(SUN50I_IOMMU_ACI_NONE, 5) |
396		    IOMMU_DM_AUT_CTRL_WR_UNAVAIL(SUN50I_IOMMU_ACI_NONE, 5));
397
398	iommu_write(iommu, IOMMU_DM_AUT_CTRL_REG(SUN50I_IOMMU_ACI_RD),
399		    IOMMU_DM_AUT_CTRL_WR_UNAVAIL(SUN50I_IOMMU_ACI_RD, 0) |
400		    IOMMU_DM_AUT_CTRL_WR_UNAVAIL(SUN50I_IOMMU_ACI_RD, 1) |
401		    IOMMU_DM_AUT_CTRL_WR_UNAVAIL(SUN50I_IOMMU_ACI_RD, 2) |
402		    IOMMU_DM_AUT_CTRL_WR_UNAVAIL(SUN50I_IOMMU_ACI_RD, 3) |
403		    IOMMU_DM_AUT_CTRL_WR_UNAVAIL(SUN50I_IOMMU_ACI_RD, 4) |
404		    IOMMU_DM_AUT_CTRL_WR_UNAVAIL(SUN50I_IOMMU_ACI_RD, 5));
405
406	iommu_write(iommu, IOMMU_DM_AUT_CTRL_REG(SUN50I_IOMMU_ACI_WR),
407		    IOMMU_DM_AUT_CTRL_RD_UNAVAIL(SUN50I_IOMMU_ACI_WR, 0) |
408		    IOMMU_DM_AUT_CTRL_RD_UNAVAIL(SUN50I_IOMMU_ACI_WR, 1) |
409		    IOMMU_DM_AUT_CTRL_RD_UNAVAIL(SUN50I_IOMMU_ACI_WR, 2) |
410		    IOMMU_DM_AUT_CTRL_RD_UNAVAIL(SUN50I_IOMMU_ACI_WR, 3) |
411		    IOMMU_DM_AUT_CTRL_RD_UNAVAIL(SUN50I_IOMMU_ACI_WR, 4) |
412		    IOMMU_DM_AUT_CTRL_RD_UNAVAIL(SUN50I_IOMMU_ACI_WR, 5));
413
414	ret = sun50i_iommu_flush_all_tlb(iommu);
415	if (ret) {
416		spin_unlock_irqrestore(&iommu->iommu_lock, flags);
417		goto err_clk_disable;
418	}
419
420	iommu_write(iommu, IOMMU_AUTO_GATING_REG, IOMMU_AUTO_GATING_ENABLE);
421	iommu_write(iommu, IOMMU_ENABLE_REG, IOMMU_ENABLE_ENABLE);
422
423	spin_unlock_irqrestore(&iommu->iommu_lock, flags);
424
425	return 0;
426
427err_clk_disable:
428	clk_disable_unprepare(iommu->clk);
429
430err_reset_assert:
431	reset_control_assert(iommu->reset);
432
433	return ret;
434}
435
436static void sun50i_iommu_disable(struct sun50i_iommu *iommu)
437{
438	unsigned long flags;
439
440	spin_lock_irqsave(&iommu->iommu_lock, flags);
441
442	iommu_write(iommu, IOMMU_ENABLE_REG, 0);
443	iommu_write(iommu, IOMMU_TTB_REG, 0);
444
445	spin_unlock_irqrestore(&iommu->iommu_lock, flags);
446
447	clk_disable_unprepare(iommu->clk);
448	reset_control_assert(iommu->reset);
449}
450
451static void *sun50i_iommu_alloc_page_table(struct sun50i_iommu *iommu,
452					   gfp_t gfp)
453{
454	dma_addr_t pt_dma;
455	u32 *page_table;
456
457	page_table = kmem_cache_zalloc(iommu->pt_pool, gfp);
458	if (!page_table)
459		return ERR_PTR(-ENOMEM);
460
461	pt_dma = dma_map_single(iommu->dev, page_table, PT_SIZE, DMA_TO_DEVICE);
462	if (dma_mapping_error(iommu->dev, pt_dma)) {
463		dev_err(iommu->dev, "Couldn't map L2 Page Table\n");
464		kmem_cache_free(iommu->pt_pool, page_table);
465		return ERR_PTR(-ENOMEM);
466	}
467
468	/* We rely on the physical address and DMA address being the same */
469	WARN_ON(pt_dma != virt_to_phys(page_table));
470
471	return page_table;
472}
473
474static void sun50i_iommu_free_page_table(struct sun50i_iommu *iommu,
475					 u32 *page_table)
476{
477	phys_addr_t pt_phys = virt_to_phys(page_table);
478
479	dma_unmap_single(iommu->dev, pt_phys, PT_SIZE, DMA_TO_DEVICE);
480	kmem_cache_free(iommu->pt_pool, page_table);
481}
482
483static u32 *sun50i_dte_get_page_table(struct sun50i_iommu_domain *sun50i_domain,
484				      dma_addr_t iova, gfp_t gfp)
485{
486	struct sun50i_iommu *iommu = sun50i_domain->iommu;
487	u32 *page_table;
488	u32 *dte_addr;
489	u32 old_dte;
490	u32 dte;
491
492	dte_addr = &sun50i_domain->dt[sun50i_iova_get_dte_index(iova)];
493	dte = *dte_addr;
494	if (sun50i_dte_is_pt_valid(dte)) {
495		phys_addr_t pt_phys = sun50i_dte_get_pt_address(dte);
496		return (u32 *)phys_to_virt(pt_phys);
497	}
498
499	page_table = sun50i_iommu_alloc_page_table(iommu, gfp);
500	if (IS_ERR(page_table))
501		return page_table;
502
503	dte = sun50i_mk_dte(virt_to_phys(page_table));
504	old_dte = cmpxchg(dte_addr, 0, dte);
505	if (old_dte) {
506		phys_addr_t installed_pt_phys =
507			sun50i_dte_get_pt_address(old_dte);
508		u32 *installed_pt = phys_to_virt(installed_pt_phys);
509		u32 *drop_pt = page_table;
510
511		page_table = installed_pt;
512		dte = old_dte;
513		sun50i_iommu_free_page_table(iommu, drop_pt);
514	}
515
516	sun50i_table_flush(sun50i_domain, page_table, NUM_PT_ENTRIES);
517	sun50i_table_flush(sun50i_domain, dte_addr, 1);
518
519	return page_table;
520}
521
522static int sun50i_iommu_map(struct iommu_domain *domain, unsigned long iova,
523			    phys_addr_t paddr, size_t size, int prot, gfp_t gfp)
524{
525	struct sun50i_iommu_domain *sun50i_domain = to_sun50i_domain(domain);
526	struct sun50i_iommu *iommu = sun50i_domain->iommu;
527	u32 pte_index;
528	u32 *page_table, *pte_addr;
529	int ret = 0;
530
531	page_table = sun50i_dte_get_page_table(sun50i_domain, iova, gfp);
532	if (IS_ERR(page_table)) {
533		ret = PTR_ERR(page_table);
534		goto out;
535	}
536
537	pte_index = sun50i_iova_get_pte_index(iova);
538	pte_addr = &page_table[pte_index];
539	if (unlikely(sun50i_pte_is_page_valid(*pte_addr))) {
540		phys_addr_t page_phys = sun50i_pte_get_page_address(*pte_addr);
541		dev_err(iommu->dev,
542			"iova %pad already mapped to %pa cannot remap to %pa prot: %#x\n",
543			&iova, &page_phys, &paddr, prot);
544		ret = -EBUSY;
545		goto out;
546	}
547
548	*pte_addr = sun50i_mk_pte(paddr, prot);
549	sun50i_table_flush(sun50i_domain, pte_addr, 1);
550
551out:
552	return ret;
553}
554
555static size_t sun50i_iommu_unmap(struct iommu_domain *domain, unsigned long iova,
556				 size_t size, struct iommu_iotlb_gather *gather)
557{
558	struct sun50i_iommu_domain *sun50i_domain = to_sun50i_domain(domain);
559	phys_addr_t pt_phys;
560	u32 *pte_addr;
561	u32 dte;
562
563	dte = sun50i_domain->dt[sun50i_iova_get_dte_index(iova)];
564	if (!sun50i_dte_is_pt_valid(dte))
565		return 0;
566
567	pt_phys = sun50i_dte_get_pt_address(dte);
568	pte_addr = (u32 *)phys_to_virt(pt_phys) + sun50i_iova_get_pte_index(iova);
569
570	if (!sun50i_pte_is_page_valid(*pte_addr))
571		return 0;
572
573	memset(pte_addr, 0, sizeof(*pte_addr));
574	sun50i_table_flush(sun50i_domain, pte_addr, 1);
575
576	return SZ_4K;
577}
578
579static phys_addr_t sun50i_iommu_iova_to_phys(struct iommu_domain *domain,
580					     dma_addr_t iova)
581{
582	struct sun50i_iommu_domain *sun50i_domain = to_sun50i_domain(domain);
583	phys_addr_t pt_phys;
584	u32 *page_table;
585	u32 dte, pte;
586
587	dte = sun50i_domain->dt[sun50i_iova_get_dte_index(iova)];
588	if (!sun50i_dte_is_pt_valid(dte))
589		return 0;
590
591	pt_phys = sun50i_dte_get_pt_address(dte);
592	page_table = (u32 *)phys_to_virt(pt_phys);
593	pte = page_table[sun50i_iova_get_pte_index(iova)];
594	if (!sun50i_pte_is_page_valid(pte))
595		return 0;
596
597	return sun50i_pte_get_page_address(pte) +
598		sun50i_iova_get_page_offset(iova);
599}
600
601static struct iommu_domain *sun50i_iommu_domain_alloc(unsigned type)
602{
603	struct sun50i_iommu_domain *sun50i_domain;
604
605	if (type != IOMMU_DOMAIN_DMA &&
606	    type != IOMMU_DOMAIN_UNMANAGED)
607		return NULL;
608
609	sun50i_domain = kzalloc(sizeof(*sun50i_domain), GFP_KERNEL);
610	if (!sun50i_domain)
611		return NULL;
612
613	if (type == IOMMU_DOMAIN_DMA &&
614	    iommu_get_dma_cookie(&sun50i_domain->domain))
615		goto err_free_domain;
616
617	sun50i_domain->dt = (u32 *)__get_free_pages(GFP_KERNEL | __GFP_ZERO,
618						    get_order(DT_SIZE));
619	if (!sun50i_domain->dt)
620		goto err_put_cookie;
621
622	refcount_set(&sun50i_domain->refcnt, 1);
623
624	sun50i_domain->domain.geometry.aperture_start = 0;
625	sun50i_domain->domain.geometry.aperture_end = DMA_BIT_MASK(32);
626	sun50i_domain->domain.geometry.force_aperture = true;
627
628	return &sun50i_domain->domain;
629
630err_put_cookie:
631	if (type == IOMMU_DOMAIN_DMA)
632		iommu_put_dma_cookie(&sun50i_domain->domain);
633
634err_free_domain:
635	kfree(sun50i_domain);
636
637	return NULL;
638}
639
640static void sun50i_iommu_domain_free(struct iommu_domain *domain)
641{
642	struct sun50i_iommu_domain *sun50i_domain = to_sun50i_domain(domain);
643
644	free_pages((unsigned long)sun50i_domain->dt, get_order(DT_SIZE));
645	sun50i_domain->dt = NULL;
646
647	iommu_put_dma_cookie(domain);
648
649	kfree(sun50i_domain);
650}
651
652static int sun50i_iommu_attach_domain(struct sun50i_iommu *iommu,
653				      struct sun50i_iommu_domain *sun50i_domain)
654{
655	iommu->domain = &sun50i_domain->domain;
656	sun50i_domain->iommu = iommu;
657
658	sun50i_domain->dt_dma = dma_map_single(iommu->dev, sun50i_domain->dt,
659					       DT_SIZE, DMA_TO_DEVICE);
660	if (dma_mapping_error(iommu->dev, sun50i_domain->dt_dma)) {
661		dev_err(iommu->dev, "Couldn't map L1 Page Table\n");
662		return -ENOMEM;
663	}
664
665	return sun50i_iommu_enable(iommu);
666}
667
668static void sun50i_iommu_detach_domain(struct sun50i_iommu *iommu,
669				       struct sun50i_iommu_domain *sun50i_domain)
670{
671	unsigned int i;
672
673	for (i = 0; i < NUM_DT_ENTRIES; i++) {
674		phys_addr_t pt_phys;
675		u32 *page_table;
676		u32 *dte_addr;
677		u32 dte;
678
679		dte_addr = &sun50i_domain->dt[i];
680		dte = *dte_addr;
681		if (!sun50i_dte_is_pt_valid(dte))
682			continue;
683
684		memset(dte_addr, 0, sizeof(*dte_addr));
685		sun50i_table_flush(sun50i_domain, dte_addr, 1);
686
687		pt_phys = sun50i_dte_get_pt_address(dte);
688		page_table = phys_to_virt(pt_phys);
689		sun50i_iommu_free_page_table(iommu, page_table);
690	}
691
692
693	sun50i_iommu_disable(iommu);
694
695	dma_unmap_single(iommu->dev, virt_to_phys(sun50i_domain->dt),
696			 DT_SIZE, DMA_TO_DEVICE);
697
698	iommu->domain = NULL;
699}
700
701static void sun50i_iommu_detach_device(struct iommu_domain *domain,
702				       struct device *dev)
703{
704	struct sun50i_iommu_domain *sun50i_domain = to_sun50i_domain(domain);
705	struct sun50i_iommu *iommu = dev_iommu_priv_get(dev);
706
707	dev_dbg(dev, "Detaching from IOMMU domain\n");
708
709	if (iommu->domain != domain)
710		return;
711
712	if (refcount_dec_and_test(&sun50i_domain->refcnt))
713		sun50i_iommu_detach_domain(iommu, sun50i_domain);
714}
715
716static int sun50i_iommu_attach_device(struct iommu_domain *domain,
717				      struct device *dev)
718{
719	struct sun50i_iommu_domain *sun50i_domain = to_sun50i_domain(domain);
720	struct sun50i_iommu *iommu;
721
722	iommu = sun50i_iommu_from_dev(dev);
723	if (!iommu)
724		return -ENODEV;
725
726	dev_dbg(dev, "Attaching to IOMMU domain\n");
727
728	refcount_inc(&sun50i_domain->refcnt);
729
730	if (iommu->domain == domain)
731		return 0;
732
733	if (iommu->domain)
734		sun50i_iommu_detach_device(iommu->domain, dev);
735
736	sun50i_iommu_attach_domain(iommu, sun50i_domain);
737
738	return 0;
739}
740
741static struct iommu_device *sun50i_iommu_probe_device(struct device *dev)
742{
743	struct sun50i_iommu *iommu;
744
745	iommu = sun50i_iommu_from_dev(dev);
746	if (!iommu)
747		return ERR_PTR(-ENODEV);
748
749	return &iommu->iommu;
750}
751
752static void sun50i_iommu_release_device(struct device *dev) {}
753
754static struct iommu_group *sun50i_iommu_device_group(struct device *dev)
755{
756	struct sun50i_iommu *iommu = sun50i_iommu_from_dev(dev);
757
758	return iommu_group_ref_get(iommu->group);
759}
760
761static int sun50i_iommu_of_xlate(struct device *dev,
762				 struct of_phandle_args *args)
763{
764	struct platform_device *iommu_pdev = of_find_device_by_node(args->np);
765	unsigned id = args->args[0];
766
767	dev_iommu_priv_set(dev, platform_get_drvdata(iommu_pdev));
768
769	return iommu_fwspec_add_ids(dev, &id, 1);
770}
771
772static const struct iommu_ops sun50i_iommu_ops = {
773	.pgsize_bitmap	= SZ_4K,
774	.attach_dev	= sun50i_iommu_attach_device,
775	.detach_dev	= sun50i_iommu_detach_device,
776	.device_group	= sun50i_iommu_device_group,
777	.domain_alloc	= sun50i_iommu_domain_alloc,
778	.domain_free	= sun50i_iommu_domain_free,
779	.flush_iotlb_all = sun50i_iommu_flush_iotlb_all,
780	.iotlb_sync	= sun50i_iommu_iotlb_sync,
781	.iova_to_phys	= sun50i_iommu_iova_to_phys,
782	.map		= sun50i_iommu_map,
783	.of_xlate	= sun50i_iommu_of_xlate,
784	.probe_device	= sun50i_iommu_probe_device,
785	.release_device	= sun50i_iommu_release_device,
786	.unmap		= sun50i_iommu_unmap,
787};
788
789static void sun50i_iommu_report_fault(struct sun50i_iommu *iommu,
790				      unsigned master, phys_addr_t iova,
791				      unsigned prot)
792{
793	dev_err(iommu->dev, "Page fault for %pad (master %d, dir %s)\n",
794		&iova, master, (prot == IOMMU_FAULT_WRITE) ? "wr" : "rd");
795
796	if (iommu->domain)
797		report_iommu_fault(iommu->domain, iommu->dev, iova, prot);
798	else
799		dev_err(iommu->dev, "Page fault while iommu not attached to any domain?\n");
800}
801
802static phys_addr_t sun50i_iommu_handle_pt_irq(struct sun50i_iommu *iommu,
803					      unsigned addr_reg,
804					      unsigned blame_reg)
805{
806	phys_addr_t iova;
807	unsigned master;
808	u32 blame;
809
810	assert_spin_locked(&iommu->iommu_lock);
811
812	iova = iommu_read(iommu, addr_reg);
813	blame = iommu_read(iommu, blame_reg);
814	master = ilog2(blame & IOMMU_INT_MASTER_MASK);
815
816	/*
817	 * If the address is not in the page table, we can't get what
818	 * operation triggered the fault. Assume it's a read
819	 * operation.
820	 */
821	sun50i_iommu_report_fault(iommu, master, iova, IOMMU_FAULT_READ);
822
823	return iova;
824}
825
826static phys_addr_t sun50i_iommu_handle_perm_irq(struct sun50i_iommu *iommu)
827{
828	enum sun50i_iommu_aci aci;
829	phys_addr_t iova;
830	unsigned master;
831	unsigned dir;
832	u32 blame;
833
834	assert_spin_locked(&iommu->iommu_lock);
835
836	blame = iommu_read(iommu, IOMMU_INT_STA_REG);
837	master = ilog2(blame & IOMMU_INT_MASTER_MASK);
838	iova = iommu_read(iommu, IOMMU_INT_ERR_ADDR_REG(master));
839	aci = sun50i_get_pte_aci(iommu_read(iommu,
840					    IOMMU_INT_ERR_DATA_REG(master)));
841
842	switch (aci) {
843		/*
844		 * If we are in the read-only domain, then it means we
845		 * tried to write.
846		 */
847	case SUN50I_IOMMU_ACI_RD:
848		dir = IOMMU_FAULT_WRITE;
849		break;
850
851		/*
852		 * If we are in the write-only domain, then it means
853		 * we tried to read.
854		 */
855	case SUN50I_IOMMU_ACI_WR:
856
857		/*
858		 * If we are in the domain without any permission, we
859		 * can't really tell. Let's default to a read
860		 * operation.
861		 */
862	case SUN50I_IOMMU_ACI_NONE:
863
864		/* WTF? */
865	case SUN50I_IOMMU_ACI_RD_WR:
866	default:
867		dir = IOMMU_FAULT_READ;
868		break;
869	}
870
871	/*
872	 * If the address is not in the page table, we can't get what
873	 * operation triggered the fault. Assume it's a read
874	 * operation.
875	 */
876	sun50i_iommu_report_fault(iommu, master, iova, dir);
877
878	return iova;
879}
880
881static irqreturn_t sun50i_iommu_irq(int irq, void *dev_id)
882{
883	u32 status, l1_status, l2_status, resets;
884	struct sun50i_iommu *iommu = dev_id;
885
886	spin_lock(&iommu->iommu_lock);
887
888	status = iommu_read(iommu, IOMMU_INT_STA_REG);
889	if (!(status & IOMMU_INT_MASK)) {
890		spin_unlock(&iommu->iommu_lock);
891		return IRQ_NONE;
892	}
893
894	l1_status = iommu_read(iommu, IOMMU_L1PG_INT_REG);
895	l2_status = iommu_read(iommu, IOMMU_L2PG_INT_REG);
896
897	if (status & IOMMU_INT_INVALID_L2PG)
898		sun50i_iommu_handle_pt_irq(iommu,
899					    IOMMU_INT_ERR_ADDR_L2_REG,
900					    IOMMU_L2PG_INT_REG);
901	else if (status & IOMMU_INT_INVALID_L1PG)
902		sun50i_iommu_handle_pt_irq(iommu,
903					   IOMMU_INT_ERR_ADDR_L1_REG,
904					   IOMMU_L1PG_INT_REG);
905	else
906		sun50i_iommu_handle_perm_irq(iommu);
907
908	iommu_write(iommu, IOMMU_INT_CLR_REG, status);
909
910	resets = (status | l1_status | l2_status) & IOMMU_INT_MASTER_MASK;
911	iommu_write(iommu, IOMMU_RESET_REG, ~resets);
912	iommu_write(iommu, IOMMU_RESET_REG, IOMMU_RESET_RELEASE_ALL);
913
914	spin_unlock(&iommu->iommu_lock);
915
916	return IRQ_HANDLED;
917}
918
919static int sun50i_iommu_probe(struct platform_device *pdev)
920{
921	struct sun50i_iommu *iommu;
922	int ret, irq;
923
924	iommu = devm_kzalloc(&pdev->dev, sizeof(*iommu), GFP_KERNEL);
925	if (!iommu)
926		return -ENOMEM;
927	spin_lock_init(&iommu->iommu_lock);
928	platform_set_drvdata(pdev, iommu);
929	iommu->dev = &pdev->dev;
930
931	iommu->pt_pool = kmem_cache_create(dev_name(&pdev->dev),
932					   PT_SIZE, PT_SIZE,
933					   SLAB_HWCACHE_ALIGN,
934					   NULL);
935	if (!iommu->pt_pool)
936		return -ENOMEM;
937
938	iommu->group = iommu_group_alloc();
939	if (IS_ERR(iommu->group)) {
940		ret = PTR_ERR(iommu->group);
941		goto err_free_cache;
942	}
943
944	iommu->base = devm_platform_ioremap_resource(pdev, 0);
945	if (IS_ERR(iommu->base)) {
946		ret = PTR_ERR(iommu->base);
947		goto err_free_group;
948	}
949
950	irq = platform_get_irq(pdev, 0);
951	if (irq < 0) {
952		ret = irq;
953		goto err_free_group;
954	}
955
956	iommu->clk = devm_clk_get(&pdev->dev, NULL);
957	if (IS_ERR(iommu->clk)) {
958		dev_err(&pdev->dev, "Couldn't get our clock.\n");
959		ret = PTR_ERR(iommu->clk);
960		goto err_free_group;
961	}
962
963	iommu->reset = devm_reset_control_get(&pdev->dev, NULL);
964	if (IS_ERR(iommu->reset)) {
965		dev_err(&pdev->dev, "Couldn't get our reset line.\n");
966		ret = PTR_ERR(iommu->reset);
967		goto err_free_group;
968	}
969
970	ret = iommu_device_sysfs_add(&iommu->iommu, &pdev->dev,
971				     NULL, dev_name(&pdev->dev));
972	if (ret)
973		goto err_free_group;
974
975	iommu_device_set_ops(&iommu->iommu, &sun50i_iommu_ops);
976	iommu_device_set_fwnode(&iommu->iommu, &pdev->dev.of_node->fwnode);
977
978	ret = iommu_device_register(&iommu->iommu);
979	if (ret)
980		goto err_remove_sysfs;
981
982	ret = devm_request_irq(&pdev->dev, irq, sun50i_iommu_irq, 0,
983			       dev_name(&pdev->dev), iommu);
984	if (ret < 0)
985		goto err_unregister;
986
987	bus_set_iommu(&platform_bus_type, &sun50i_iommu_ops);
988
989	return 0;
990
991err_unregister:
992	iommu_device_unregister(&iommu->iommu);
993
994err_remove_sysfs:
995	iommu_device_sysfs_remove(&iommu->iommu);
996
997err_free_group:
998	iommu_group_put(iommu->group);
999
1000err_free_cache:
1001	kmem_cache_destroy(iommu->pt_pool);
1002
1003	return ret;
1004}
1005
1006static const struct of_device_id sun50i_iommu_dt[] = {
1007	{ .compatible = "allwinner,sun50i-h6-iommu", },
1008	{ /* sentinel */ },
1009};
1010MODULE_DEVICE_TABLE(of, sun50i_iommu_dt);
1011
1012static struct platform_driver sun50i_iommu_driver = {
1013	.driver		= {
1014		.name			= "sun50i-iommu",
1015		.of_match_table 	= sun50i_iommu_dt,
1016		.suppress_bind_attrs	= true,
1017	}
1018};
1019builtin_platform_driver_probe(sun50i_iommu_driver, sun50i_iommu_probe);
1020
1021MODULE_DESCRIPTION("Allwinner H6 IOMMU driver");
1022MODULE_AUTHOR("Maxime Ripard <maxime@cerno.tech>");
1023MODULE_AUTHOR("zhuxianbin <zhuxianbin@allwinnertech.com>");
1024MODULE_LICENSE("Dual BSD/GPL");
1025