1// SPDX-License-Identifier: GPL-2.0
2
3/* Copyright (c) 2012-2018, The Linux Foundation. All rights reserved.
4 * Copyright (C) 2019-2020 Linaro Ltd.
5 */
6
7#include <linux/types.h>
8#include <linux/bitfield.h>
9#include <linux/bug.h>
10#include <linux/dma-mapping.h>
11#include <linux/iommu.h>
12#include <linux/io.h>
13#include <linux/soc/qcom/smem.h>
14
15#include "ipa.h"
16#include "ipa_reg.h"
17#include "ipa_data.h"
18#include "ipa_cmd.h"
19#include "ipa_mem.h"
20#include "ipa_table.h"
21#include "gsi_trans.h"
22
23/* "Canary" value placed between memory regions to detect overflow */
24#define IPA_MEM_CANARY_VAL		cpu_to_le32(0xdeadbeef)
25
26/* SMEM host id representing the modem. */
27#define QCOM_SMEM_HOST_MODEM	1
28
29/* Add an immediate command to a transaction that zeroes a memory region */
30static void
31ipa_mem_zero_region_add(struct gsi_trans *trans, const struct ipa_mem *mem)
32{
33	struct ipa *ipa = container_of(trans->gsi, struct ipa, gsi);
34	dma_addr_t addr = ipa->zero_addr;
35
36	if (!mem->size)
37		return;
38
39	ipa_cmd_dma_shared_mem_add(trans, mem->offset, mem->size, addr, true);
40}
41
42/**
43 * ipa_mem_setup() - Set up IPA AP and modem shared memory areas
44 * @ipa:	IPA pointer
45 *
46 * Set up the shared memory regions in IPA local memory.  This involves
47 * zero-filling memory regions, and in the case of header memory, telling
48 * the IPA where it's located.
49 *
50 * This function performs the initial setup of this memory.  If the modem
51 * crashes, its regions are re-zeroed in ipa_mem_zero_modem().
52 *
53 * The AP informs the modem where its portions of memory are located
54 * in a QMI exchange that occurs at modem startup.
55 *
56 * Return:	0 if successful, or a negative error code
57 */
58int ipa_mem_setup(struct ipa *ipa)
59{
60	dma_addr_t addr = ipa->zero_addr;
61	struct gsi_trans *trans;
62	u32 offset;
63	u16 size;
64
65	/* Get a transaction to define the header memory region and to zero
66	 * the processing context and modem memory regions.
67	 */
68	trans = ipa_cmd_trans_alloc(ipa, 4);
69	if (!trans) {
70		dev_err(&ipa->pdev->dev, "no transaction for memory setup\n");
71		return -EBUSY;
72	}
73
74	/* Initialize IPA-local header memory.  The modem and AP header
75	 * regions are contiguous, and initialized together.
76	 */
77	offset = ipa->mem[IPA_MEM_MODEM_HEADER].offset;
78	size = ipa->mem[IPA_MEM_MODEM_HEADER].size;
79	size += ipa->mem[IPA_MEM_AP_HEADER].size;
80
81	ipa_cmd_hdr_init_local_add(trans, offset, size, addr);
82
83	ipa_mem_zero_region_add(trans, &ipa->mem[IPA_MEM_MODEM_PROC_CTX]);
84
85	ipa_mem_zero_region_add(trans, &ipa->mem[IPA_MEM_AP_PROC_CTX]);
86
87	ipa_mem_zero_region_add(trans, &ipa->mem[IPA_MEM_MODEM]);
88
89	gsi_trans_commit_wait(trans);
90
91	/* Tell the hardware where the processing context area is located */
92	iowrite32(ipa->mem_offset + offset,
93		  ipa->reg_virt + IPA_REG_LOCAL_PKT_PROC_CNTXT_BASE_OFFSET);
94
95	return 0;
96}
97
98void ipa_mem_teardown(struct ipa *ipa)
99{
100	/* Nothing to do */
101}
102
103#ifdef IPA_VALIDATE
104
105static bool ipa_mem_valid(struct ipa *ipa, enum ipa_mem_id mem_id)
106{
107	const struct ipa_mem *mem = &ipa->mem[mem_id];
108	struct device *dev = &ipa->pdev->dev;
109	u16 size_multiple;
110
111	/* Other than modem memory, sizes must be a multiple of 8 */
112	size_multiple = mem_id == IPA_MEM_MODEM ? 4 : 8;
113	if (mem->size % size_multiple)
114		dev_err(dev, "region %u size not a multiple of %u bytes\n",
115			mem_id, size_multiple);
116	else if (mem->offset % 8)
117		dev_err(dev, "region %u offset not 8-byte aligned\n", mem_id);
118	else if (mem->offset < mem->canary_count * sizeof(__le32))
119		dev_err(dev, "region %u offset too small for %hu canaries\n",
120			mem_id, mem->canary_count);
121	else if (mem->offset + mem->size > ipa->mem_size)
122		dev_err(dev, "region %u ends beyond memory limit (0x%08x)\n",
123			mem_id, ipa->mem_size);
124	else
125		return true;
126
127	return false;
128}
129
130#else /* !IPA_VALIDATE */
131
132static bool ipa_mem_valid(struct ipa *ipa, enum ipa_mem_id mem_id)
133{
134	return true;
135}
136
137#endif /*! IPA_VALIDATE */
138
139/**
140 * ipa_mem_config() - Configure IPA shared memory
141 * @ipa:	IPA pointer
142 *
143 * Return:	0 if successful, or a negative error code
144 */
145int ipa_mem_config(struct ipa *ipa)
146{
147	struct device *dev = &ipa->pdev->dev;
148	enum ipa_mem_id mem_id;
149	dma_addr_t addr;
150	u32 mem_size;
151	void *virt;
152	u32 val;
153
154	/* Check the advertised location and size of the shared memory area */
155	val = ioread32(ipa->reg_virt + IPA_REG_SHARED_MEM_SIZE_OFFSET);
156
157	/* The fields in the register are in 8 byte units */
158	ipa->mem_offset = 8 * u32_get_bits(val, SHARED_MEM_BADDR_FMASK);
159	/* Make sure the end is within the region's mapped space */
160	mem_size = 8 * u32_get_bits(val, SHARED_MEM_SIZE_FMASK);
161
162	/* If the sizes don't match, issue a warning */
163	if (ipa->mem_offset + mem_size > ipa->mem_size) {
164		dev_warn(dev, "ignoring larger reported memory size: 0x%08x\n",
165			mem_size);
166	} else if (ipa->mem_offset + mem_size < ipa->mem_size) {
167		dev_warn(dev, "limiting IPA memory size to 0x%08x\n",
168			 mem_size);
169		ipa->mem_size = mem_size;
170	}
171
172	/* Prealloc DMA memory for zeroing regions */
173	virt = dma_alloc_coherent(dev, IPA_MEM_MAX, &addr, GFP_KERNEL);
174	if (!virt)
175		return -ENOMEM;
176	ipa->zero_addr = addr;
177	ipa->zero_virt = virt;
178	ipa->zero_size = IPA_MEM_MAX;
179
180	/* Verify each defined memory region is valid, and if indicated
181	 * for the region, write "canary" values in the space prior to
182	 * the region's base address.
183	 */
184	for (mem_id = 0; mem_id < ipa->mem_count; mem_id++) {
185		const struct ipa_mem *mem = &ipa->mem[mem_id];
186		u16 canary_count;
187		__le32 *canary;
188
189		/* Validate all regions (even undefined ones) */
190		if (!ipa_mem_valid(ipa, mem_id))
191			goto err_dma_free;
192
193		/* Skip over undefined regions */
194		if (!mem->offset && !mem->size)
195			continue;
196
197		canary_count = mem->canary_count;
198		if (!canary_count)
199			continue;
200
201		/* Write canary values in the space before the region */
202		canary = ipa->mem_virt + ipa->mem_offset + mem->offset;
203		do
204			*--canary = IPA_MEM_CANARY_VAL;
205		while (--canary_count);
206	}
207
208	/* Make sure filter and route table memory regions are valid */
209	if (!ipa_table_valid(ipa))
210		goto err_dma_free;
211
212	/* Validate memory-related properties relevant to immediate commands */
213	if (!ipa_cmd_data_valid(ipa))
214		goto err_dma_free;
215
216	/* Verify the microcontroller ring alignment (0 is OK too) */
217	if (ipa->mem[IPA_MEM_UC_EVENT_RING].offset % 1024) {
218		dev_err(dev, "microcontroller ring not 1024-byte aligned\n");
219		goto err_dma_free;
220	}
221
222	return 0;
223
224err_dma_free:
225	dma_free_coherent(dev, IPA_MEM_MAX, ipa->zero_virt, ipa->zero_addr);
226
227	return -EINVAL;
228}
229
230/* Inverse of ipa_mem_config() */
231void ipa_mem_deconfig(struct ipa *ipa)
232{
233	struct device *dev = &ipa->pdev->dev;
234
235	dma_free_coherent(dev, ipa->zero_size, ipa->zero_virt, ipa->zero_addr);
236	ipa->zero_size = 0;
237	ipa->zero_virt = NULL;
238	ipa->zero_addr = 0;
239}
240
241/**
242 * ipa_mem_zero_modem() - Zero IPA-local memory regions owned by the modem
243 * @ipa:	IPA pointer
244 *
245 * Zero regions of IPA-local memory used by the modem.  These are configured
246 * (and initially zeroed) by ipa_mem_setup(), but if the modem crashes and
247 * restarts via SSR we need to re-initialize them.  A QMI message tells the
248 * modem where to find regions of IPA local memory it needs to know about
249 * (these included).
250 */
251int ipa_mem_zero_modem(struct ipa *ipa)
252{
253	struct gsi_trans *trans;
254
255	/* Get a transaction to zero the modem memory, modem header,
256	 * and modem processing context regions.
257	 */
258	trans = ipa_cmd_trans_alloc(ipa, 3);
259	if (!trans) {
260		dev_err(&ipa->pdev->dev,
261			"no transaction to zero modem memory\n");
262		return -EBUSY;
263	}
264
265	ipa_mem_zero_region_add(trans, &ipa->mem[IPA_MEM_MODEM_HEADER]);
266
267	ipa_mem_zero_region_add(trans, &ipa->mem[IPA_MEM_MODEM_PROC_CTX]);
268
269	ipa_mem_zero_region_add(trans, &ipa->mem[IPA_MEM_MODEM]);
270
271	gsi_trans_commit_wait(trans);
272
273	return 0;
274}
275
276/**
277 * ipa_imem_init() - Initialize IMEM memory used by the IPA
278 * @ipa:	IPA pointer
279 * @addr:	Physical address of the IPA region in IMEM
280 * @size:	Size (bytes) of the IPA region in IMEM
281 *
282 * IMEM is a block of shared memory separate from system DRAM, and
283 * a portion of this memory is available for the IPA to use.  The
284 * modem accesses this memory directly, but the IPA accesses it
285 * via the IOMMU, using the AP's credentials.
286 *
287 * If this region exists (size > 0) we map it for read/write access
288 * through the IOMMU using the IPA device.
289 *
290 * Note: @addr and @size are not guaranteed to be page-aligned.
291 */
292static int ipa_imem_init(struct ipa *ipa, unsigned long addr, size_t size)
293{
294	struct device *dev = &ipa->pdev->dev;
295	struct iommu_domain *domain;
296	unsigned long iova;
297	phys_addr_t phys;
298	int ret;
299
300	if (!size)
301		return 0;	/* IMEM memory not used */
302
303	domain = iommu_get_domain_for_dev(dev);
304	if (!domain) {
305		dev_err(dev, "no IOMMU domain found for IMEM\n");
306		return -EINVAL;
307	}
308
309	/* Align the address down and the size up to page boundaries */
310	phys = addr & PAGE_MASK;
311	size = PAGE_ALIGN(size + addr - phys);
312	iova = phys;	/* We just want a direct mapping */
313
314	ret = iommu_map(domain, iova, phys, size, IOMMU_READ | IOMMU_WRITE);
315	if (ret)
316		return ret;
317
318	ipa->imem_iova = iova;
319	ipa->imem_size = size;
320
321	return 0;
322}
323
324static void ipa_imem_exit(struct ipa *ipa)
325{
326	struct iommu_domain *domain;
327	struct device *dev;
328
329	if (!ipa->imem_size)
330		return;
331
332	dev = &ipa->pdev->dev;
333	domain = iommu_get_domain_for_dev(dev);
334	if (domain) {
335		size_t size;
336
337		size = iommu_unmap(domain, ipa->imem_iova, ipa->imem_size);
338		if (size != ipa->imem_size)
339			dev_warn(dev, "unmapped %zu IMEM bytes, expected %lu\n",
340				 size, ipa->imem_size);
341	} else {
342		dev_err(dev, "couldn't get IPA IOMMU domain for IMEM\n");
343	}
344
345	ipa->imem_size = 0;
346	ipa->imem_iova = 0;
347}
348
349/**
350 * ipa_smem_init() - Initialize SMEM memory used by the IPA
351 * @ipa:	IPA pointer
352 * @item:	Item ID of SMEM memory
353 * @size:	Size (bytes) of SMEM memory region
354 *
355 * SMEM is a managed block of shared DRAM, from which numbered "items"
356 * can be allocated.  One item is designated for use by the IPA.
357 *
358 * The modem accesses SMEM memory directly, but the IPA accesses it
359 * via the IOMMU, using the AP's credentials.
360 *
361 * If size provided is non-zero, we allocate it and map it for
362 * access through the IOMMU.
363 *
364 * Note: @size and the item address are is not guaranteed to be page-aligned.
365 */
366static int ipa_smem_init(struct ipa *ipa, u32 item, size_t size)
367{
368	struct device *dev = &ipa->pdev->dev;
369	struct iommu_domain *domain;
370	unsigned long iova;
371	phys_addr_t phys;
372	phys_addr_t addr;
373	size_t actual;
374	void *virt;
375	int ret;
376
377	if (!size)
378		return 0;	/* SMEM memory not used */
379
380	/* SMEM is memory shared between the AP and another system entity
381	 * (in this case, the modem).  An allocation from SMEM is persistent
382	 * until the AP reboots; there is no way to free an allocated SMEM
383	 * region.  Allocation only reserves the space; to use it you need
384	 * to "get" a pointer it (this implies no reference counting).
385	 * The item might have already been allocated, in which case we
386	 * use it unless the size isn't what we expect.
387	 */
388	ret = qcom_smem_alloc(QCOM_SMEM_HOST_MODEM, item, size);
389	if (ret && ret != -EEXIST) {
390		dev_err(dev, "error %d allocating size %zu SMEM item %u\n",
391			ret, size, item);
392		return ret;
393	}
394
395	/* Now get the address of the SMEM memory region */
396	virt = qcom_smem_get(QCOM_SMEM_HOST_MODEM, item, &actual);
397	if (IS_ERR(virt)) {
398		ret = PTR_ERR(virt);
399		dev_err(dev, "error %d getting SMEM item %u\n", ret, item);
400		return ret;
401	}
402
403	/* In case the region was already allocated, verify the size */
404	if (ret && actual != size) {
405		dev_err(dev, "SMEM item %u has size %zu, expected %zu\n",
406			item, actual, size);
407		return -EINVAL;
408	}
409
410	domain = iommu_get_domain_for_dev(dev);
411	if (!domain) {
412		dev_err(dev, "no IOMMU domain found for SMEM\n");
413		return -EINVAL;
414	}
415
416	/* Align the address down and the size up to a page boundary */
417	addr = qcom_smem_virt_to_phys(virt);
418	phys = addr & PAGE_MASK;
419	size = PAGE_ALIGN(size + addr - phys);
420	iova = phys;	/* We just want a direct mapping */
421
422	ret = iommu_map(domain, iova, phys, size, IOMMU_READ | IOMMU_WRITE);
423	if (ret)
424		return ret;
425
426	ipa->smem_iova = iova;
427	ipa->smem_size = size;
428
429	return 0;
430}
431
432static void ipa_smem_exit(struct ipa *ipa)
433{
434	struct device *dev = &ipa->pdev->dev;
435	struct iommu_domain *domain;
436
437	domain = iommu_get_domain_for_dev(dev);
438	if (domain) {
439		size_t size;
440
441		size = iommu_unmap(domain, ipa->smem_iova, ipa->smem_size);
442		if (size != ipa->smem_size)
443			dev_warn(dev, "unmapped %zu SMEM bytes, expected %lu\n",
444				 size, ipa->smem_size);
445
446	} else {
447		dev_err(dev, "couldn't get IPA IOMMU domain for SMEM\n");
448	}
449
450	ipa->smem_size = 0;
451	ipa->smem_iova = 0;
452}
453
454/* Perform memory region-related initialization */
455int ipa_mem_init(struct ipa *ipa, const struct ipa_mem_data *mem_data)
456{
457	struct device *dev = &ipa->pdev->dev;
458	struct resource *res;
459	int ret;
460
461	if (mem_data->local_count > IPA_MEM_COUNT) {
462		dev_err(dev, "to many memory regions (%u > %u)\n",
463			mem_data->local_count, IPA_MEM_COUNT);
464		return -EINVAL;
465	}
466
467	ret = dma_set_mask_and_coherent(&ipa->pdev->dev, DMA_BIT_MASK(64));
468	if (ret) {
469		dev_err(dev, "error %d setting DMA mask\n", ret);
470		return ret;
471	}
472
473	res = platform_get_resource_byname(ipa->pdev, IORESOURCE_MEM,
474					   "ipa-shared");
475	if (!res) {
476		dev_err(dev,
477			"DT error getting \"ipa-shared\" memory property\n");
478		return -ENODEV;
479	}
480
481	ipa->mem_virt = memremap(res->start, resource_size(res), MEMREMAP_WC);
482	if (!ipa->mem_virt) {
483		dev_err(dev, "unable to remap \"ipa-shared\" memory\n");
484		return -ENOMEM;
485	}
486
487	ipa->mem_addr = res->start;
488	ipa->mem_size = resource_size(res);
489
490	/* The ipa->mem[] array is indexed by enum ipa_mem_id values */
491	ipa->mem_count = mem_data->local_count;
492	ipa->mem = mem_data->local;
493
494	ret = ipa_imem_init(ipa, mem_data->imem_addr, mem_data->imem_size);
495	if (ret)
496		goto err_unmap;
497
498	ret = ipa_smem_init(ipa, mem_data->smem_id, mem_data->smem_size);
499	if (ret)
500		goto err_imem_exit;
501
502	return 0;
503
504err_imem_exit:
505	ipa_imem_exit(ipa);
506err_unmap:
507	memunmap(ipa->mem_virt);
508
509	return ret;
510}
511
512/* Inverse of ipa_mem_init() */
513void ipa_mem_exit(struct ipa *ipa)
514{
515	ipa_smem_exit(ipa);
516	ipa_imem_exit(ipa);
517	memunmap(ipa->mem_virt);
518}
519