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_RESET_RELEASE_ALL			0xffffffff
31#define IOMMU_ENABLE_REG		0x020
32#define IOMMU_ENABLE_ENABLE			BIT(0)
33
34#define IOMMU_BYPASS_REG		0x030
35#define IOMMU_AUTO_GATING_REG		0x040
36#define IOMMU_AUTO_GATING_ENABLE		BIT(0)
37
38#define IOMMU_WBUF_CTRL_REG		0x044
39#define IOMMU_OOO_CTRL_REG		0x048
40#define IOMMU_4KB_BDY_PRT_CTRL_REG	0x04c
41#define IOMMU_TTB_REG			0x050
42#define IOMMU_TLB_ENABLE_REG		0x060
43#define IOMMU_TLB_PREFETCH_REG		0x070
44#define IOMMU_TLB_PREFETCH_MASTER_ENABLE(m)	BIT(m)
45
46#define IOMMU_TLB_FLUSH_REG		0x080
47#define IOMMU_TLB_FLUSH_PTW_CACHE		BIT(17)
48#define IOMMU_TLB_FLUSH_MACRO_TLB		BIT(16)
49#define IOMMU_TLB_FLUSH_MICRO_TLB(i)		(BIT(i) & GENMASK(5, 0))
50
51#define IOMMU_TLB_IVLD_ADDR_REG		0x090
52#define IOMMU_TLB_IVLD_ADDR_MASK_REG	0x094
53#define IOMMU_TLB_IVLD_ENABLE_REG	0x098
54#define IOMMU_TLB_IVLD_ENABLE_ENABLE		BIT(0)
55
56#define IOMMU_PC_IVLD_ADDR_REG		0x0a0
57#define IOMMU_PC_IVLD_ENABLE_REG	0x0a8
58#define IOMMU_PC_IVLD_ENABLE_ENABLE		BIT(0)
59
60#define IOMMU_DM_AUT_CTRL_REG(d)	(0x0b0 + ((d) / 2) * 4)
61#define IOMMU_DM_AUT_CTRL_RD_UNAVAIL(d, m)	(1 << (((d & 1) * 16) + ((m) * 2)))
62#define IOMMU_DM_AUT_CTRL_WR_UNAVAIL(d, m)	(1 << (((d & 1) * 16) + ((m) * 2) + 1))
63
64#define IOMMU_DM_AUT_OVWT_REG		0x0d0
65#define IOMMU_INT_ENABLE_REG		0x100
66#define IOMMU_INT_CLR_REG		0x104
67#define IOMMU_INT_STA_REG		0x108
68#define IOMMU_INT_ERR_ADDR_REG(i)	(0x110 + (i) * 4)
69#define IOMMU_INT_ERR_ADDR_L1_REG	0x130
70#define IOMMU_INT_ERR_ADDR_L2_REG	0x134
71#define IOMMU_INT_ERR_DATA_REG(i)	(0x150 + (i) * 4)
72#define IOMMU_L1PG_INT_REG		0x0180
73#define IOMMU_L2PG_INT_REG		0x0184
74
75#define IOMMU_INT_INVALID_L2PG			BIT(17)
76#define IOMMU_INT_INVALID_L1PG			BIT(16)
77#define IOMMU_INT_MASTER_PERMISSION(m)		BIT(m)
78#define IOMMU_INT_MASTER_MASK			(IOMMU_INT_MASTER_PERMISSION(0) | \
79						 IOMMU_INT_MASTER_PERMISSION(1) | \
80						 IOMMU_INT_MASTER_PERMISSION(2) | \
81						 IOMMU_INT_MASTER_PERMISSION(3) | \
82						 IOMMU_INT_MASTER_PERMISSION(4) | \
83						 IOMMU_INT_MASTER_PERMISSION(5))
84#define IOMMU_INT_MASK				(IOMMU_INT_INVALID_L1PG | \
85						 IOMMU_INT_INVALID_L2PG | \
86						 IOMMU_INT_MASTER_MASK)
87
88#define PT_ENTRY_SIZE			sizeof(u32)
89
90#define NUM_DT_ENTRIES			4096
91#define DT_SIZE				(NUM_DT_ENTRIES * PT_ENTRY_SIZE)
92
93#define NUM_PT_ENTRIES			256
94#define PT_SIZE				(NUM_PT_ENTRIES * PT_ENTRY_SIZE)
95
96#define SPAGE_SIZE			4096
97
98struct sun50i_iommu {
99	struct iommu_device iommu;
100
101	/* Lock to modify the IOMMU registers */
102	spinlock_t iommu_lock;
103
104	struct device *dev;
105	void __iomem *base;
106	struct reset_control *reset;
107	struct clk *clk;
108
109	struct iommu_domain *domain;
110	struct iommu_group *group;
111	struct kmem_cache *pt_pool;
112};
113
114struct sun50i_iommu_domain {
115	struct iommu_domain domain;
116
117	/* Number of devices attached to the domain */
118	refcount_t refcnt;
119
120	/* L1 Page Table */
121	u32 *dt;
122	dma_addr_t dt_dma;
123
124	struct sun50i_iommu *iommu;
125};
126
127static struct sun50i_iommu_domain *to_sun50i_domain(struct iommu_domain *domain)
128{
129	return container_of(domain, struct sun50i_iommu_domain, domain);
130}
131
132static struct sun50i_iommu *sun50i_iommu_from_dev(struct device *dev)
133{
134	return dev_iommu_priv_get(dev);
135}
136
137static u32 iommu_read(struct sun50i_iommu *iommu, u32 offset)
138{
139	return readl(iommu->base + offset);
140}
141
142static void iommu_write(struct sun50i_iommu *iommu, u32 offset, u32 value)
143{
144	writel(value, iommu->base + offset);
145}
146
147/*
148 * The Allwinner H6 IOMMU uses a 2-level page table.
149 *
150 * The first level is the usual Directory Table (DT), that consists of
151 * 4096 4-bytes Directory Table Entries (DTE), each pointing to a Page
152 * Table (PT).
153 *
154 * Each PT consits of 256 4-bytes Page Table Entries (PTE), each
155 * pointing to a 4kB page of physical memory.
156 *
157 * The IOMMU supports a single DT, pointed by the IOMMU_TTB_REG
158 * register that contains its physical address.
159 */
160
161#define SUN50I_IOVA_DTE_MASK	GENMASK(31, 20)
162#define SUN50I_IOVA_PTE_MASK	GENMASK(19, 12)
163#define SUN50I_IOVA_PAGE_MASK	GENMASK(11, 0)
164
165static u32 sun50i_iova_get_dte_index(dma_addr_t iova)
166{
167	return FIELD_GET(SUN50I_IOVA_DTE_MASK, iova);
168}
169
170static u32 sun50i_iova_get_pte_index(dma_addr_t iova)
171{
172	return FIELD_GET(SUN50I_IOVA_PTE_MASK, iova);
173}
174
175static u32 sun50i_iova_get_page_offset(dma_addr_t iova)
176{
177	return FIELD_GET(SUN50I_IOVA_PAGE_MASK, iova);
178}
179
180/*
181 * Each Directory Table Entry has a Page Table address and a valid
182 * bit:
183
184 * +---------------------+-----------+-+
185 * | PT address          | Reserved  |V|
186 * +---------------------+-----------+-+
187 *  31:10 - Page Table address
188 *   9:2  - Reserved
189 *   1:0  - 1 if the entry is valid
190 */
191
192#define SUN50I_DTE_PT_ADDRESS_MASK	GENMASK(31, 10)
193#define SUN50I_DTE_PT_ATTRS		GENMASK(1, 0)
194#define SUN50I_DTE_PT_VALID		1
195
196static phys_addr_t sun50i_dte_get_pt_address(u32 dte)
197{
198	return (phys_addr_t)dte & SUN50I_DTE_PT_ADDRESS_MASK;
199}
200
201static bool sun50i_dte_is_pt_valid(u32 dte)
202{
203	return (dte & SUN50I_DTE_PT_ATTRS) == SUN50I_DTE_PT_VALID;
204}
205
206static u32 sun50i_mk_dte(dma_addr_t pt_dma)
207{
208	return (pt_dma & SUN50I_DTE_PT_ADDRESS_MASK) | SUN50I_DTE_PT_VALID;
209}
210
211/*
212 * Each PTE has a Page address, an authority index and a valid bit:
213 *
214 * +----------------+-----+-----+-----+---+-----+
215 * | Page address   | Rsv | ACI | Rsv | V | Rsv |
216 * +----------------+-----+-----+-----+---+-----+
217 *  31:12 - Page address
218 *  11:8  - Reserved
219 *   7:4  - Authority Control Index
220 *   3:2  - Reserved
221 *     1  - 1 if the entry is valid
222 *     0  - Reserved
223 *
224 * The way permissions work is that the IOMMU has 16 "domains" that
225 * can be configured to give each masters either read or write
226 * permissions through the IOMMU_DM_AUT_CTRL_REG registers. The domain
227 * 0 seems like the default domain, and its permissions in the
228 * IOMMU_DM_AUT_CTRL_REG are only read-only, so it's not really
229 * useful to enforce any particular permission.
230 *
231 * Each page entry will then have a reference to the domain they are
232 * affected to, so that we can actually enforce them on a per-page
233 * basis.
234 *
235 * In order to make it work with the IOMMU framework, we will be using
236 * 4 different domains, starting at 1: RD_WR, RD, WR and NONE
237 * depending on the permission we want to enforce. Each domain will
238 * have each master setup in the same way, since the IOMMU framework
239 * doesn't seem to restrict page access on a per-device basis. And
240 * then we will use the relevant domain index when generating the page
241 * table entry depending on the permissions we want to be enforced.
242 */
243
244enum sun50i_iommu_aci {
245	SUN50I_IOMMU_ACI_DO_NOT_USE = 0,
246	SUN50I_IOMMU_ACI_NONE,
247	SUN50I_IOMMU_ACI_RD,
248	SUN50I_IOMMU_ACI_WR,
249	SUN50I_IOMMU_ACI_RD_WR,
250};
251
252#define SUN50I_PTE_PAGE_ADDRESS_MASK	GENMASK(31, 12)
253#define SUN50I_PTE_ACI_MASK		GENMASK(7, 4)
254#define SUN50I_PTE_PAGE_VALID		BIT(1)
255
256static phys_addr_t sun50i_pte_get_page_address(u32 pte)
257{
258	return (phys_addr_t)pte & SUN50I_PTE_PAGE_ADDRESS_MASK;
259}
260
261static enum sun50i_iommu_aci sun50i_get_pte_aci(u32 pte)
262{
263	return FIELD_GET(SUN50I_PTE_ACI_MASK, pte);
264}
265
266static bool sun50i_pte_is_page_valid(u32 pte)
267{
268	return pte & SUN50I_PTE_PAGE_VALID;
269}
270
271static u32 sun50i_mk_pte(phys_addr_t page, int prot)
272{
273	enum sun50i_iommu_aci aci;
274	u32 flags = 0;
275
276	if ((prot & (IOMMU_READ | IOMMU_WRITE)) == (IOMMU_READ | IOMMU_WRITE))
277		aci = SUN50I_IOMMU_ACI_RD_WR;
278	else if (prot & IOMMU_READ)
279		aci = SUN50I_IOMMU_ACI_RD;
280	else if (prot & IOMMU_WRITE)
281		aci = SUN50I_IOMMU_ACI_WR;
282	else
283		aci = SUN50I_IOMMU_ACI_NONE;
284
285	flags |= FIELD_PREP(SUN50I_PTE_ACI_MASK, aci);
286	page &= SUN50I_PTE_PAGE_ADDRESS_MASK;
287	return page | flags | SUN50I_PTE_PAGE_VALID;
288}
289
290static void sun50i_table_flush(struct sun50i_iommu_domain *sun50i_domain,
291			       void *vaddr, unsigned int count)
292{
293	struct sun50i_iommu *iommu = sun50i_domain->iommu;
294	dma_addr_t dma = virt_to_phys(vaddr);
295	size_t size = count * PT_ENTRY_SIZE;
296
297	dma_sync_single_for_device(iommu->dev, dma, size, DMA_TO_DEVICE);
298}
299
300static void sun50i_iommu_zap_iova(struct sun50i_iommu *iommu,
301				  unsigned long iova)
302{
303	u32 reg;
304	int ret;
305
306	iommu_write(iommu, IOMMU_TLB_IVLD_ADDR_REG, iova);
307	iommu_write(iommu, IOMMU_TLB_IVLD_ADDR_MASK_REG, GENMASK(31, 12));
308	iommu_write(iommu, IOMMU_TLB_IVLD_ENABLE_REG,
309		    IOMMU_TLB_IVLD_ENABLE_ENABLE);
310
311	ret = readl_poll_timeout_atomic(iommu->base + IOMMU_TLB_IVLD_ENABLE_REG,
312					reg, !reg, 1, 2000);
313	if (ret)
314		dev_warn(iommu->dev, "TLB invalidation timed out!\n");
315}
316
317static void sun50i_iommu_zap_ptw_cache(struct sun50i_iommu *iommu,
318				       unsigned long iova)
319{
320	u32 reg;
321	int ret;
322
323	iommu_write(iommu, IOMMU_PC_IVLD_ADDR_REG, iova);
324	iommu_write(iommu, IOMMU_PC_IVLD_ENABLE_REG,
325		    IOMMU_PC_IVLD_ENABLE_ENABLE);
326
327	ret = readl_poll_timeout_atomic(iommu->base + IOMMU_PC_IVLD_ENABLE_REG,
328					reg, !reg, 1, 2000);
329	if (ret)
330		dev_warn(iommu->dev, "PTW cache invalidation timed out!\n");
331}
332
333static void sun50i_iommu_zap_range(struct sun50i_iommu *iommu,
334				   unsigned long iova, size_t size)
335{
336	assert_spin_locked(&iommu->iommu_lock);
337
338	iommu_write(iommu, IOMMU_AUTO_GATING_REG, 0);
339
340	sun50i_iommu_zap_iova(iommu, iova);
341	sun50i_iommu_zap_iova(iommu, iova + SPAGE_SIZE);
342	if (size > SPAGE_SIZE) {
343		sun50i_iommu_zap_iova(iommu, iova + size);
344		sun50i_iommu_zap_iova(iommu, iova + size + SPAGE_SIZE);
345	}
346	sun50i_iommu_zap_ptw_cache(iommu, iova);
347	sun50i_iommu_zap_ptw_cache(iommu, iova + SZ_1M);
348	if (size > SZ_1M) {
349		sun50i_iommu_zap_ptw_cache(iommu, iova + size);
350		sun50i_iommu_zap_ptw_cache(iommu, iova + size + SZ_1M);
351	}
352
353	iommu_write(iommu, IOMMU_AUTO_GATING_REG, IOMMU_AUTO_GATING_ENABLE);
354}
355
356static int sun50i_iommu_flush_all_tlb(struct sun50i_iommu *iommu)
357{
358	u32 reg;
359	int ret;
360
361	assert_spin_locked(&iommu->iommu_lock);
362
363	iommu_write(iommu,
364		    IOMMU_TLB_FLUSH_REG,
365		    IOMMU_TLB_FLUSH_PTW_CACHE |
366		    IOMMU_TLB_FLUSH_MACRO_TLB |
367		    IOMMU_TLB_FLUSH_MICRO_TLB(5) |
368		    IOMMU_TLB_FLUSH_MICRO_TLB(4) |
369		    IOMMU_TLB_FLUSH_MICRO_TLB(3) |
370		    IOMMU_TLB_FLUSH_MICRO_TLB(2) |
371		    IOMMU_TLB_FLUSH_MICRO_TLB(1) |
372		    IOMMU_TLB_FLUSH_MICRO_TLB(0));
373
374	ret = readl_poll_timeout_atomic(iommu->base + IOMMU_TLB_FLUSH_REG,
375					reg, !reg,
376					1, 2000);
377	if (ret)
378		dev_warn(iommu->dev, "TLB Flush timed out!\n");
379
380	return ret;
381}
382
383static void sun50i_iommu_flush_iotlb_all(struct iommu_domain *domain)
384{
385	struct sun50i_iommu_domain *sun50i_domain = to_sun50i_domain(domain);
386	struct sun50i_iommu *iommu = sun50i_domain->iommu;
387	unsigned long flags;
388
389	/*
390	 * At boot, we'll have a first call into .flush_iotlb_all right after
391	 * .probe_device, and since we link our (single) domain to our iommu in
392	 * the .attach_device callback, we don't have that pointer set.
393	 *
394	 * It shouldn't really be any trouble to ignore it though since we flush
395	 * all caches as part of the device powerup.
396	 */
397	if (!iommu)
398		return;
399
400	spin_lock_irqsave(&iommu->iommu_lock, flags);
401	sun50i_iommu_flush_all_tlb(iommu);
402	spin_unlock_irqrestore(&iommu->iommu_lock, flags);
403}
404
405static void sun50i_iommu_iotlb_sync_map(struct iommu_domain *domain,
406					unsigned long iova, size_t size)
407{
408	struct sun50i_iommu_domain *sun50i_domain = to_sun50i_domain(domain);
409	struct sun50i_iommu *iommu = sun50i_domain->iommu;
410	unsigned long flags;
411
412	spin_lock_irqsave(&iommu->iommu_lock, flags);
413	sun50i_iommu_zap_range(iommu, iova, size);
414	spin_unlock_irqrestore(&iommu->iommu_lock, flags);
415}
416
417static void sun50i_iommu_iotlb_sync(struct iommu_domain *domain,
418				    struct iommu_iotlb_gather *gather)
419{
420	sun50i_iommu_flush_iotlb_all(domain);
421}
422
423static int sun50i_iommu_enable(struct sun50i_iommu *iommu)
424{
425	struct sun50i_iommu_domain *sun50i_domain;
426	unsigned long flags;
427	int ret;
428
429	if (!iommu->domain)
430		return 0;
431
432	sun50i_domain = to_sun50i_domain(iommu->domain);
433
434	ret = reset_control_deassert(iommu->reset);
435	if (ret)
436		return ret;
437
438	ret = clk_prepare_enable(iommu->clk);
439	if (ret)
440		goto err_reset_assert;
441
442	spin_lock_irqsave(&iommu->iommu_lock, flags);
443
444	iommu_write(iommu, IOMMU_TTB_REG, sun50i_domain->dt_dma);
445	iommu_write(iommu, IOMMU_TLB_PREFETCH_REG,
446		    IOMMU_TLB_PREFETCH_MASTER_ENABLE(0) |
447		    IOMMU_TLB_PREFETCH_MASTER_ENABLE(1) |
448		    IOMMU_TLB_PREFETCH_MASTER_ENABLE(2) |
449		    IOMMU_TLB_PREFETCH_MASTER_ENABLE(3) |
450		    IOMMU_TLB_PREFETCH_MASTER_ENABLE(4) |
451		    IOMMU_TLB_PREFETCH_MASTER_ENABLE(5));
452	iommu_write(iommu, IOMMU_INT_ENABLE_REG, IOMMU_INT_MASK);
453	iommu_write(iommu, IOMMU_DM_AUT_CTRL_REG(SUN50I_IOMMU_ACI_NONE),
454		    IOMMU_DM_AUT_CTRL_RD_UNAVAIL(SUN50I_IOMMU_ACI_NONE, 0) |
455		    IOMMU_DM_AUT_CTRL_WR_UNAVAIL(SUN50I_IOMMU_ACI_NONE, 0) |
456		    IOMMU_DM_AUT_CTRL_RD_UNAVAIL(SUN50I_IOMMU_ACI_NONE, 1) |
457		    IOMMU_DM_AUT_CTRL_WR_UNAVAIL(SUN50I_IOMMU_ACI_NONE, 1) |
458		    IOMMU_DM_AUT_CTRL_RD_UNAVAIL(SUN50I_IOMMU_ACI_NONE, 2) |
459		    IOMMU_DM_AUT_CTRL_WR_UNAVAIL(SUN50I_IOMMU_ACI_NONE, 2) |
460		    IOMMU_DM_AUT_CTRL_RD_UNAVAIL(SUN50I_IOMMU_ACI_NONE, 3) |
461		    IOMMU_DM_AUT_CTRL_WR_UNAVAIL(SUN50I_IOMMU_ACI_NONE, 3) |
462		    IOMMU_DM_AUT_CTRL_RD_UNAVAIL(SUN50I_IOMMU_ACI_NONE, 4) |
463		    IOMMU_DM_AUT_CTRL_WR_UNAVAIL(SUN50I_IOMMU_ACI_NONE, 4) |
464		    IOMMU_DM_AUT_CTRL_RD_UNAVAIL(SUN50I_IOMMU_ACI_NONE, 5) |
465		    IOMMU_DM_AUT_CTRL_WR_UNAVAIL(SUN50I_IOMMU_ACI_NONE, 5));
466
467	iommu_write(iommu, IOMMU_DM_AUT_CTRL_REG(SUN50I_IOMMU_ACI_RD),
468		    IOMMU_DM_AUT_CTRL_WR_UNAVAIL(SUN50I_IOMMU_ACI_RD, 0) |
469		    IOMMU_DM_AUT_CTRL_WR_UNAVAIL(SUN50I_IOMMU_ACI_RD, 1) |
470		    IOMMU_DM_AUT_CTRL_WR_UNAVAIL(SUN50I_IOMMU_ACI_RD, 2) |
471		    IOMMU_DM_AUT_CTRL_WR_UNAVAIL(SUN50I_IOMMU_ACI_RD, 3) |
472		    IOMMU_DM_AUT_CTRL_WR_UNAVAIL(SUN50I_IOMMU_ACI_RD, 4) |
473		    IOMMU_DM_AUT_CTRL_WR_UNAVAIL(SUN50I_IOMMU_ACI_RD, 5));
474
475	iommu_write(iommu, IOMMU_DM_AUT_CTRL_REG(SUN50I_IOMMU_ACI_WR),
476		    IOMMU_DM_AUT_CTRL_RD_UNAVAIL(SUN50I_IOMMU_ACI_WR, 0) |
477		    IOMMU_DM_AUT_CTRL_RD_UNAVAIL(SUN50I_IOMMU_ACI_WR, 1) |
478		    IOMMU_DM_AUT_CTRL_RD_UNAVAIL(SUN50I_IOMMU_ACI_WR, 2) |
479		    IOMMU_DM_AUT_CTRL_RD_UNAVAIL(SUN50I_IOMMU_ACI_WR, 3) |
480		    IOMMU_DM_AUT_CTRL_RD_UNAVAIL(SUN50I_IOMMU_ACI_WR, 4) |
481		    IOMMU_DM_AUT_CTRL_RD_UNAVAIL(SUN50I_IOMMU_ACI_WR, 5));
482
483	ret = sun50i_iommu_flush_all_tlb(iommu);
484	if (ret) {
485		spin_unlock_irqrestore(&iommu->iommu_lock, flags);
486		goto err_clk_disable;
487	}
488
489	iommu_write(iommu, IOMMU_AUTO_GATING_REG, IOMMU_AUTO_GATING_ENABLE);
490	iommu_write(iommu, IOMMU_ENABLE_REG, IOMMU_ENABLE_ENABLE);
491
492	spin_unlock_irqrestore(&iommu->iommu_lock, flags);
493
494	return 0;
495
496err_clk_disable:
497	clk_disable_unprepare(iommu->clk);
498
499err_reset_assert:
500	reset_control_assert(iommu->reset);
501
502	return ret;
503}
504
505static void sun50i_iommu_disable(struct sun50i_iommu *iommu)
506{
507	unsigned long flags;
508
509	spin_lock_irqsave(&iommu->iommu_lock, flags);
510
511	iommu_write(iommu, IOMMU_ENABLE_REG, 0);
512	iommu_write(iommu, IOMMU_TTB_REG, 0);
513
514	spin_unlock_irqrestore(&iommu->iommu_lock, flags);
515
516	clk_disable_unprepare(iommu->clk);
517	reset_control_assert(iommu->reset);
518}
519
520static void *sun50i_iommu_alloc_page_table(struct sun50i_iommu *iommu,
521					   gfp_t gfp)
522{
523	dma_addr_t pt_dma;
524	u32 *page_table;
525
526	page_table = kmem_cache_zalloc(iommu->pt_pool, gfp);
527	if (!page_table)
528		return ERR_PTR(-ENOMEM);
529
530	pt_dma = dma_map_single(iommu->dev, page_table, PT_SIZE, DMA_TO_DEVICE);
531	if (dma_mapping_error(iommu->dev, pt_dma)) {
532		dev_err(iommu->dev, "Couldn't map L2 Page Table\n");
533		kmem_cache_free(iommu->pt_pool, page_table);
534		return ERR_PTR(-ENOMEM);
535	}
536
537	/* We rely on the physical address and DMA address being the same */
538	WARN_ON(pt_dma != virt_to_phys(page_table));
539
540	return page_table;
541}
542
543static void sun50i_iommu_free_page_table(struct sun50i_iommu *iommu,
544					 u32 *page_table)
545{
546	phys_addr_t pt_phys = virt_to_phys(page_table);
547
548	dma_unmap_single(iommu->dev, pt_phys, PT_SIZE, DMA_TO_DEVICE);
549	kmem_cache_free(iommu->pt_pool, page_table);
550}
551
552static u32 *sun50i_dte_get_page_table(struct sun50i_iommu_domain *sun50i_domain,
553				      dma_addr_t iova, gfp_t gfp)
554{
555	struct sun50i_iommu *iommu = sun50i_domain->iommu;
556	u32 *page_table;
557	u32 *dte_addr;
558	u32 old_dte;
559	u32 dte;
560
561	dte_addr = &sun50i_domain->dt[sun50i_iova_get_dte_index(iova)];
562	dte = *dte_addr;
563	if (sun50i_dte_is_pt_valid(dte)) {
564		phys_addr_t pt_phys = sun50i_dte_get_pt_address(dte);
565		return (u32 *)phys_to_virt(pt_phys);
566	}
567
568	page_table = sun50i_iommu_alloc_page_table(iommu, gfp);
569	if (IS_ERR(page_table))
570		return page_table;
571
572	dte = sun50i_mk_dte(virt_to_phys(page_table));
573	old_dte = cmpxchg(dte_addr, 0, dte);
574	if (old_dte) {
575		phys_addr_t installed_pt_phys =
576			sun50i_dte_get_pt_address(old_dte);
577		u32 *installed_pt = phys_to_virt(installed_pt_phys);
578		u32 *drop_pt = page_table;
579
580		page_table = installed_pt;
581		dte = old_dte;
582		sun50i_iommu_free_page_table(iommu, drop_pt);
583	}
584
585	sun50i_table_flush(sun50i_domain, page_table, NUM_PT_ENTRIES);
586	sun50i_table_flush(sun50i_domain, dte_addr, 1);
587
588	return page_table;
589}
590
591static int sun50i_iommu_map(struct iommu_domain *domain, unsigned long iova,
592			    phys_addr_t paddr, size_t size, int prot, gfp_t gfp)
593{
594	struct sun50i_iommu_domain *sun50i_domain = to_sun50i_domain(domain);
595	struct sun50i_iommu *iommu = sun50i_domain->iommu;
596	u32 pte_index;
597	u32 *page_table, *pte_addr;
598	int ret = 0;
599
600	page_table = sun50i_dte_get_page_table(sun50i_domain, iova, gfp);
601	if (IS_ERR(page_table)) {
602		ret = PTR_ERR(page_table);
603		goto out;
604	}
605
606	pte_index = sun50i_iova_get_pte_index(iova);
607	pte_addr = &page_table[pte_index];
608	if (unlikely(sun50i_pte_is_page_valid(*pte_addr))) {
609		phys_addr_t page_phys = sun50i_pte_get_page_address(*pte_addr);
610		dev_err(iommu->dev,
611			"iova %pad already mapped to %pa cannot remap to %pa prot: %#x\n",
612			&iova, &page_phys, &paddr, prot);
613		ret = -EBUSY;
614		goto out;
615	}
616
617	*pte_addr = sun50i_mk_pte(paddr, prot);
618	sun50i_table_flush(sun50i_domain, pte_addr, 1);
619
620out:
621	return ret;
622}
623
624static size_t sun50i_iommu_unmap(struct iommu_domain *domain, unsigned long iova,
625				 size_t size, struct iommu_iotlb_gather *gather)
626{
627	struct sun50i_iommu_domain *sun50i_domain = to_sun50i_domain(domain);
628	phys_addr_t pt_phys;
629	u32 *pte_addr;
630	u32 dte;
631
632	dte = sun50i_domain->dt[sun50i_iova_get_dte_index(iova)];
633	if (!sun50i_dte_is_pt_valid(dte))
634		return 0;
635
636	pt_phys = sun50i_dte_get_pt_address(dte);
637	pte_addr = (u32 *)phys_to_virt(pt_phys) + sun50i_iova_get_pte_index(iova);
638
639	if (!sun50i_pte_is_page_valid(*pte_addr))
640		return 0;
641
642	memset(pte_addr, 0, sizeof(*pte_addr));
643	sun50i_table_flush(sun50i_domain, pte_addr, 1);
644
645	return SZ_4K;
646}
647
648static phys_addr_t sun50i_iommu_iova_to_phys(struct iommu_domain *domain,
649					     dma_addr_t iova)
650{
651	struct sun50i_iommu_domain *sun50i_domain = to_sun50i_domain(domain);
652	phys_addr_t pt_phys;
653	u32 *page_table;
654	u32 dte, pte;
655
656	dte = sun50i_domain->dt[sun50i_iova_get_dte_index(iova)];
657	if (!sun50i_dte_is_pt_valid(dte))
658		return 0;
659
660	pt_phys = sun50i_dte_get_pt_address(dte);
661	page_table = (u32 *)phys_to_virt(pt_phys);
662	pte = page_table[sun50i_iova_get_pte_index(iova)];
663	if (!sun50i_pte_is_page_valid(pte))
664		return 0;
665
666	return sun50i_pte_get_page_address(pte) +
667		sun50i_iova_get_page_offset(iova);
668}
669
670static struct iommu_domain *sun50i_iommu_domain_alloc(unsigned type)
671{
672	struct sun50i_iommu_domain *sun50i_domain;
673
674	if (type != IOMMU_DOMAIN_DMA &&
675	    type != IOMMU_DOMAIN_UNMANAGED)
676		return NULL;
677
678	sun50i_domain = kzalloc(sizeof(*sun50i_domain), GFP_KERNEL);
679	if (!sun50i_domain)
680		return NULL;
681
682	sun50i_domain->dt = (u32 *)__get_free_pages(GFP_KERNEL | __GFP_ZERO,
683						    get_order(DT_SIZE));
684	if (!sun50i_domain->dt)
685		goto err_free_domain;
686
687	refcount_set(&sun50i_domain->refcnt, 1);
688
689	sun50i_domain->domain.geometry.aperture_start = 0;
690	sun50i_domain->domain.geometry.aperture_end = DMA_BIT_MASK(32);
691	sun50i_domain->domain.geometry.force_aperture = true;
692
693	return &sun50i_domain->domain;
694
695err_free_domain:
696	kfree(sun50i_domain);
697
698	return NULL;
699}
700
701static void sun50i_iommu_domain_free(struct iommu_domain *domain)
702{
703	struct sun50i_iommu_domain *sun50i_domain = to_sun50i_domain(domain);
704
705	free_pages((unsigned long)sun50i_domain->dt, get_order(DT_SIZE));
706	sun50i_domain->dt = NULL;
707
708	kfree(sun50i_domain);
709}
710
711static int sun50i_iommu_attach_domain(struct sun50i_iommu *iommu,
712				      struct sun50i_iommu_domain *sun50i_domain)
713{
714	iommu->domain = &sun50i_domain->domain;
715	sun50i_domain->iommu = iommu;
716
717	sun50i_domain->dt_dma = dma_map_single(iommu->dev, sun50i_domain->dt,
718					       DT_SIZE, DMA_TO_DEVICE);
719	if (dma_mapping_error(iommu->dev, sun50i_domain->dt_dma)) {
720		dev_err(iommu->dev, "Couldn't map L1 Page Table\n");
721		return -ENOMEM;
722	}
723
724	return sun50i_iommu_enable(iommu);
725}
726
727static void sun50i_iommu_detach_domain(struct sun50i_iommu *iommu,
728				       struct sun50i_iommu_domain *sun50i_domain)
729{
730	unsigned int i;
731
732	for (i = 0; i < NUM_DT_ENTRIES; i++) {
733		phys_addr_t pt_phys;
734		u32 *page_table;
735		u32 *dte_addr;
736		u32 dte;
737
738		dte_addr = &sun50i_domain->dt[i];
739		dte = *dte_addr;
740		if (!sun50i_dte_is_pt_valid(dte))
741			continue;
742
743		memset(dte_addr, 0, sizeof(*dte_addr));
744		sun50i_table_flush(sun50i_domain, dte_addr, 1);
745
746		pt_phys = sun50i_dte_get_pt_address(dte);
747		page_table = phys_to_virt(pt_phys);
748		sun50i_iommu_free_page_table(iommu, page_table);
749	}
750
751
752	sun50i_iommu_disable(iommu);
753
754	dma_unmap_single(iommu->dev, virt_to_phys(sun50i_domain->dt),
755			 DT_SIZE, DMA_TO_DEVICE);
756
757	iommu->domain = NULL;
758}
759
760static void sun50i_iommu_detach_device(struct iommu_domain *domain,
761				       struct device *dev)
762{
763	struct sun50i_iommu_domain *sun50i_domain = to_sun50i_domain(domain);
764	struct sun50i_iommu *iommu = dev_iommu_priv_get(dev);
765
766	dev_dbg(dev, "Detaching from IOMMU domain\n");
767
768	if (iommu->domain != domain)
769		return;
770
771	if (refcount_dec_and_test(&sun50i_domain->refcnt))
772		sun50i_iommu_detach_domain(iommu, sun50i_domain);
773}
774
775static int sun50i_iommu_attach_device(struct iommu_domain *domain,
776				      struct device *dev)
777{
778	struct sun50i_iommu_domain *sun50i_domain = to_sun50i_domain(domain);
779	struct sun50i_iommu *iommu;
780
781	iommu = sun50i_iommu_from_dev(dev);
782	if (!iommu)
783		return -ENODEV;
784
785	dev_dbg(dev, "Attaching to IOMMU domain\n");
786
787	refcount_inc(&sun50i_domain->refcnt);
788
789	if (iommu->domain == domain)
790		return 0;
791
792	if (iommu->domain)
793		sun50i_iommu_detach_device(iommu->domain, dev);
794
795	sun50i_iommu_attach_domain(iommu, sun50i_domain);
796
797	return 0;
798}
799
800static struct iommu_device *sun50i_iommu_probe_device(struct device *dev)
801{
802	struct sun50i_iommu *iommu;
803
804	iommu = sun50i_iommu_from_dev(dev);
805	if (!iommu)
806		return ERR_PTR(-ENODEV);
807
808	return &iommu->iommu;
809}
810
811static struct iommu_group *sun50i_iommu_device_group(struct device *dev)
812{
813	struct sun50i_iommu *iommu = sun50i_iommu_from_dev(dev);
814
815	return iommu_group_ref_get(iommu->group);
816}
817
818static int sun50i_iommu_of_xlate(struct device *dev,
819				 struct of_phandle_args *args)
820{
821	struct platform_device *iommu_pdev = of_find_device_by_node(args->np);
822	unsigned id = args->args[0];
823
824	dev_iommu_priv_set(dev, platform_get_drvdata(iommu_pdev));
825
826	return iommu_fwspec_add_ids(dev, &id, 1);
827}
828
829static const struct iommu_ops sun50i_iommu_ops = {
830	.pgsize_bitmap	= SZ_4K,
831	.device_group	= sun50i_iommu_device_group,
832	.domain_alloc	= sun50i_iommu_domain_alloc,
833	.of_xlate	= sun50i_iommu_of_xlate,
834	.probe_device	= sun50i_iommu_probe_device,
835	.default_domain_ops = &(const struct iommu_domain_ops) {
836		.attach_dev	= sun50i_iommu_attach_device,
837		.flush_iotlb_all = sun50i_iommu_flush_iotlb_all,
838		.iotlb_sync_map = sun50i_iommu_iotlb_sync_map,
839		.iotlb_sync	= sun50i_iommu_iotlb_sync,
840		.iova_to_phys	= sun50i_iommu_iova_to_phys,
841		.map		= sun50i_iommu_map,
842		.unmap		= sun50i_iommu_unmap,
843		.free		= sun50i_iommu_domain_free,
844	}
845};
846
847static void sun50i_iommu_report_fault(struct sun50i_iommu *iommu,
848				      unsigned master, phys_addr_t iova,
849				      unsigned prot)
850{
851	dev_err(iommu->dev, "Page fault for %pad (master %d, dir %s)\n",
852		&iova, master, (prot == IOMMU_FAULT_WRITE) ? "wr" : "rd");
853
854	if (iommu->domain)
855		report_iommu_fault(iommu->domain, iommu->dev, iova, prot);
856	else
857		dev_err(iommu->dev, "Page fault while iommu not attached to any domain?\n");
858
859	sun50i_iommu_zap_range(iommu, iova, SPAGE_SIZE);
860}
861
862static phys_addr_t sun50i_iommu_handle_pt_irq(struct sun50i_iommu *iommu,
863					      unsigned addr_reg,
864					      unsigned blame_reg)
865{
866	phys_addr_t iova;
867	unsigned master;
868	u32 blame;
869
870	assert_spin_locked(&iommu->iommu_lock);
871
872	iova = iommu_read(iommu, addr_reg);
873	blame = iommu_read(iommu, blame_reg);
874	master = ilog2(blame & IOMMU_INT_MASTER_MASK);
875
876	/*
877	 * If the address is not in the page table, we can't get what
878	 * operation triggered the fault. Assume it's a read
879	 * operation.
880	 */
881	sun50i_iommu_report_fault(iommu, master, iova, IOMMU_FAULT_READ);
882
883	return iova;
884}
885
886static phys_addr_t sun50i_iommu_handle_perm_irq(struct sun50i_iommu *iommu)
887{
888	enum sun50i_iommu_aci aci;
889	phys_addr_t iova;
890	unsigned master;
891	unsigned dir;
892	u32 blame;
893
894	assert_spin_locked(&iommu->iommu_lock);
895
896	blame = iommu_read(iommu, IOMMU_INT_STA_REG);
897	master = ilog2(blame & IOMMU_INT_MASTER_MASK);
898	iova = iommu_read(iommu, IOMMU_INT_ERR_ADDR_REG(master));
899	aci = sun50i_get_pte_aci(iommu_read(iommu,
900					    IOMMU_INT_ERR_DATA_REG(master)));
901
902	switch (aci) {
903		/*
904		 * If we are in the read-only domain, then it means we
905		 * tried to write.
906		 */
907	case SUN50I_IOMMU_ACI_RD:
908		dir = IOMMU_FAULT_WRITE;
909		break;
910
911		/*
912		 * If we are in the write-only domain, then it means
913		 * we tried to read.
914		 */
915	case SUN50I_IOMMU_ACI_WR:
916
917		/*
918		 * If we are in the domain without any permission, we
919		 * can't really tell. Let's default to a read
920		 * operation.
921		 */
922	case SUN50I_IOMMU_ACI_NONE:
923
924		/* WTF? */
925	case SUN50I_IOMMU_ACI_RD_WR:
926	default:
927		dir = IOMMU_FAULT_READ;
928		break;
929	}
930
931	/*
932	 * If the address is not in the page table, we can't get what
933	 * operation triggered the fault. Assume it's a read
934	 * operation.
935	 */
936	sun50i_iommu_report_fault(iommu, master, iova, dir);
937
938	return iova;
939}
940
941static irqreturn_t sun50i_iommu_irq(int irq, void *dev_id)
942{
943	u32 status, l1_status, l2_status, resets;
944	struct sun50i_iommu *iommu = dev_id;
945
946	spin_lock(&iommu->iommu_lock);
947
948	status = iommu_read(iommu, IOMMU_INT_STA_REG);
949	if (!(status & IOMMU_INT_MASK)) {
950		spin_unlock(&iommu->iommu_lock);
951		return IRQ_NONE;
952	}
953
954	l1_status = iommu_read(iommu, IOMMU_L1PG_INT_REG);
955	l2_status = iommu_read(iommu, IOMMU_L2PG_INT_REG);
956
957	if (status & IOMMU_INT_INVALID_L2PG)
958		sun50i_iommu_handle_pt_irq(iommu,
959					    IOMMU_INT_ERR_ADDR_L2_REG,
960					    IOMMU_L2PG_INT_REG);
961	else if (status & IOMMU_INT_INVALID_L1PG)
962		sun50i_iommu_handle_pt_irq(iommu,
963					   IOMMU_INT_ERR_ADDR_L1_REG,
964					   IOMMU_L1PG_INT_REG);
965	else
966		sun50i_iommu_handle_perm_irq(iommu);
967
968	iommu_write(iommu, IOMMU_INT_CLR_REG, status);
969
970	resets = (status | l1_status | l2_status) & IOMMU_INT_MASTER_MASK;
971	iommu_write(iommu, IOMMU_RESET_REG, ~resets);
972	iommu_write(iommu, IOMMU_RESET_REG, IOMMU_RESET_RELEASE_ALL);
973
974	spin_unlock(&iommu->iommu_lock);
975
976	return IRQ_HANDLED;
977}
978
979static int sun50i_iommu_probe(struct platform_device *pdev)
980{
981	struct sun50i_iommu *iommu;
982	int ret, irq;
983
984	iommu = devm_kzalloc(&pdev->dev, sizeof(*iommu), GFP_KERNEL);
985	if (!iommu)
986		return -ENOMEM;
987	spin_lock_init(&iommu->iommu_lock);
988	platform_set_drvdata(pdev, iommu);
989	iommu->dev = &pdev->dev;
990
991	iommu->pt_pool = kmem_cache_create(dev_name(&pdev->dev),
992					   PT_SIZE, PT_SIZE,
993					   SLAB_HWCACHE_ALIGN,
994					   NULL);
995	if (!iommu->pt_pool)
996		return -ENOMEM;
997
998	iommu->group = iommu_group_alloc();
999	if (IS_ERR(iommu->group)) {
1000		ret = PTR_ERR(iommu->group);
1001		goto err_free_cache;
1002	}
1003
1004	iommu->base = devm_platform_ioremap_resource(pdev, 0);
1005	if (IS_ERR(iommu->base)) {
1006		ret = PTR_ERR(iommu->base);
1007		goto err_free_group;
1008	}
1009
1010	irq = platform_get_irq(pdev, 0);
1011	if (irq < 0) {
1012		ret = irq;
1013		goto err_free_group;
1014	}
1015
1016	iommu->clk = devm_clk_get(&pdev->dev, NULL);
1017	if (IS_ERR(iommu->clk)) {
1018		dev_err(&pdev->dev, "Couldn't get our clock.\n");
1019		ret = PTR_ERR(iommu->clk);
1020		goto err_free_group;
1021	}
1022
1023	iommu->reset = devm_reset_control_get(&pdev->dev, NULL);
1024	if (IS_ERR(iommu->reset)) {
1025		dev_err(&pdev->dev, "Couldn't get our reset line.\n");
1026		ret = PTR_ERR(iommu->reset);
1027		goto err_free_group;
1028	}
1029
1030	ret = iommu_device_sysfs_add(&iommu->iommu, &pdev->dev,
1031				     NULL, dev_name(&pdev->dev));
1032	if (ret)
1033		goto err_free_group;
1034
1035	ret = iommu_device_register(&iommu->iommu, &sun50i_iommu_ops, &pdev->dev);
1036	if (ret)
1037		goto err_remove_sysfs;
1038
1039	ret = devm_request_irq(&pdev->dev, irq, sun50i_iommu_irq, 0,
1040			       dev_name(&pdev->dev), iommu);
1041	if (ret < 0)
1042		goto err_unregister;
1043
1044	return 0;
1045
1046err_unregister:
1047	iommu_device_unregister(&iommu->iommu);
1048
1049err_remove_sysfs:
1050	iommu_device_sysfs_remove(&iommu->iommu);
1051
1052err_free_group:
1053	iommu_group_put(iommu->group);
1054
1055err_free_cache:
1056	kmem_cache_destroy(iommu->pt_pool);
1057
1058	return ret;
1059}
1060
1061static const struct of_device_id sun50i_iommu_dt[] = {
1062	{ .compatible = "allwinner,sun50i-h6-iommu", },
1063	{ /* sentinel */ },
1064};
1065MODULE_DEVICE_TABLE(of, sun50i_iommu_dt);
1066
1067static struct platform_driver sun50i_iommu_driver = {
1068	.driver		= {
1069		.name			= "sun50i-iommu",
1070		.of_match_table 	= sun50i_iommu_dt,
1071		.suppress_bind_attrs	= true,
1072	}
1073};
1074builtin_platform_driver_probe(sun50i_iommu_driver, sun50i_iommu_probe);
1075
1076MODULE_DESCRIPTION("Allwinner H6 IOMMU driver");
1077MODULE_AUTHOR("Maxime Ripard <maxime@cerno.tech>");
1078MODULE_AUTHOR("zhuxianbin <zhuxianbin@allwinnertech.com>");
1079