xref: /linux/drivers/gpu/drm/imagination/pvr_vm_mips.c (revision 36ec807b627b4c0a0a382f0ae48eac7187d14b2b)
1 // SPDX-License-Identifier: GPL-2.0-only OR MIT
2 /* Copyright (c) 2023 Imagination Technologies Ltd. */
3 
4 #include "pvr_device.h"
5 #include "pvr_fw_mips.h"
6 #include "pvr_gem.h"
7 #include "pvr_mmu.h"
8 #include "pvr_rogue_mips.h"
9 #include "pvr_vm.h"
10 #include "pvr_vm_mips.h"
11 
12 #include <drm/drm_managed.h>
13 #include <linux/dma-mapping.h>
14 #include <linux/err.h>
15 #include <linux/slab.h>
16 #include <linux/types.h>
17 #include <linux/vmalloc.h>
18 
19 /**
20  * pvr_vm_mips_init() - Initialise MIPS FW pagetable
21  * @pvr_dev: Target PowerVR device.
22  *
23  * Returns:
24  *  * 0 on success,
25  *  * -%EINVAL,
26  *  * Any error returned by pvr_gem_object_create(), or
27  *  * And error returned by pvr_gem_object_vmap().
28  */
29 int
30 pvr_vm_mips_init(struct pvr_device *pvr_dev)
31 {
32 	u32 pt_size = 1 << ROGUE_MIPSFW_LOG2_PAGETABLE_SIZE_4K(pvr_dev);
33 	struct device *dev = from_pvr_device(pvr_dev)->dev;
34 	struct pvr_fw_mips_data *mips_data;
35 	u32 phys_bus_width;
36 	int page_nr;
37 	int err;
38 
39 	/* Page table size must be at most ROGUE_MIPSFW_MAX_NUM_PAGETABLE_PAGES * 4k pages. */
40 	if (pt_size > ROGUE_MIPSFW_MAX_NUM_PAGETABLE_PAGES * SZ_4K)
41 		return -EINVAL;
42 
43 	if (PVR_FEATURE_VALUE(pvr_dev, phys_bus_width, &phys_bus_width))
44 		return -EINVAL;
45 
46 	mips_data = drmm_kzalloc(from_pvr_device(pvr_dev), sizeof(*mips_data), GFP_KERNEL);
47 	if (!mips_data)
48 		return -ENOMEM;
49 
50 	for (page_nr = 0; page_nr < PVR_MIPS_PT_PAGE_COUNT; page_nr++) {
51 		mips_data->pt_pages[page_nr] = alloc_page(GFP_KERNEL | __GFP_ZERO);
52 		if (!mips_data->pt_pages[page_nr]) {
53 			err = -ENOMEM;
54 			goto err_free_pages;
55 		}
56 
57 		mips_data->pt_dma_addr[page_nr] = dma_map_page(dev, mips_data->pt_pages[page_nr], 0,
58 							       PAGE_SIZE, DMA_TO_DEVICE);
59 		if (dma_mapping_error(dev, mips_data->pt_dma_addr[page_nr])) {
60 			err = -ENOMEM;
61 			__free_page(mips_data->pt_pages[page_nr]);
62 			goto err_free_pages;
63 		}
64 	}
65 
66 	mips_data->pt = vmap(mips_data->pt_pages, pt_size >> PAGE_SHIFT, VM_MAP,
67 			     pgprot_writecombine(PAGE_KERNEL));
68 	if (!mips_data->pt) {
69 		err = -ENOMEM;
70 		goto err_free_pages;
71 	}
72 
73 	mips_data->pfn_mask = (phys_bus_width > 32) ? ROGUE_MIPSFW_ENTRYLO_PFN_MASK_ABOVE_32BIT :
74 						      ROGUE_MIPSFW_ENTRYLO_PFN_MASK;
75 
76 	mips_data->cache_policy = (phys_bus_width > 32) ? ROGUE_MIPSFW_CACHED_POLICY_ABOVE_32BIT :
77 							  ROGUE_MIPSFW_CACHED_POLICY;
78 
79 	pvr_dev->fw_dev.processor_data.mips_data = mips_data;
80 
81 	return 0;
82 
83 err_free_pages:
84 	while (--page_nr >= 0) {
85 		dma_unmap_page(from_pvr_device(pvr_dev)->dev,
86 			       mips_data->pt_dma_addr[page_nr], PAGE_SIZE, DMA_TO_DEVICE);
87 
88 		__free_page(mips_data->pt_pages[page_nr]);
89 	}
90 
91 	return err;
92 }
93 
94 /**
95  * pvr_vm_mips_fini() - Release MIPS FW pagetable
96  * @pvr_dev: Target PowerVR device.
97  */
98 void
99 pvr_vm_mips_fini(struct pvr_device *pvr_dev)
100 {
101 	struct pvr_fw_device *fw_dev = &pvr_dev->fw_dev;
102 	struct pvr_fw_mips_data *mips_data = fw_dev->processor_data.mips_data;
103 	int page_nr;
104 
105 	vunmap(mips_data->pt);
106 	for (page_nr = PVR_MIPS_PT_PAGE_COUNT - 1; page_nr >= 0; page_nr--) {
107 		dma_unmap_page(from_pvr_device(pvr_dev)->dev,
108 			       mips_data->pt_dma_addr[page_nr], PAGE_SIZE, DMA_TO_DEVICE);
109 
110 		__free_page(mips_data->pt_pages[page_nr]);
111 	}
112 
113 	fw_dev->processor_data.mips_data = NULL;
114 }
115 
116 static u32
117 get_mips_pte_flags(bool read, bool write, u32 cache_policy)
118 {
119 	u32 flags = 0;
120 
121 	if (read && write) /* Read/write. */
122 		flags |= ROGUE_MIPSFW_ENTRYLO_DIRTY_EN;
123 	else if (write)    /* Write only. */
124 		flags |= ROGUE_MIPSFW_ENTRYLO_READ_INHIBIT_EN;
125 	else
126 		WARN_ON(!read);
127 
128 	flags |= cache_policy << ROGUE_MIPSFW_ENTRYLO_CACHE_POLICY_SHIFT;
129 
130 	flags |= ROGUE_MIPSFW_ENTRYLO_VALID_EN | ROGUE_MIPSFW_ENTRYLO_GLOBAL_EN;
131 
132 	return flags;
133 }
134 
135 /**
136  * pvr_vm_mips_map() - Map a FW object into MIPS address space
137  * @pvr_dev: Target PowerVR device.
138  * @fw_obj: FW object to map.
139  *
140  * Returns:
141  *  * 0 on success,
142  *  * -%EINVAL if object does not reside within FW address space, or
143  *  * Any error returned by pvr_fw_object_get_dma_addr().
144  */
145 int
146 pvr_vm_mips_map(struct pvr_device *pvr_dev, struct pvr_fw_object *fw_obj)
147 {
148 	struct pvr_fw_device *fw_dev = &pvr_dev->fw_dev;
149 	struct pvr_fw_mips_data *mips_data = fw_dev->processor_data.mips_data;
150 	struct pvr_gem_object *pvr_obj = fw_obj->gem;
151 	const u64 start = fw_obj->fw_mm_node.start;
152 	const u64 size = fw_obj->fw_mm_node.size;
153 	u64 end;
154 	u32 cache_policy;
155 	u32 pte_flags;
156 	s32 start_pfn;
157 	s32 end_pfn;
158 	s32 pfn;
159 	int err;
160 
161 	if (check_add_overflow(start, size - 1, &end))
162 		return -EINVAL;
163 
164 	if (start < ROGUE_FW_HEAP_BASE ||
165 	    start >= ROGUE_FW_HEAP_BASE + fw_dev->fw_heap_info.raw_size ||
166 	    end < ROGUE_FW_HEAP_BASE ||
167 	    end >= ROGUE_FW_HEAP_BASE + fw_dev->fw_heap_info.raw_size ||
168 	    (start & ROGUE_MIPSFW_PAGE_MASK_4K) ||
169 	    ((end + 1) & ROGUE_MIPSFW_PAGE_MASK_4K))
170 		return -EINVAL;
171 
172 	start_pfn = (start & fw_dev->fw_heap_info.offset_mask) >> ROGUE_MIPSFW_LOG2_PAGE_SIZE_4K;
173 	end_pfn = (end & fw_dev->fw_heap_info.offset_mask) >> ROGUE_MIPSFW_LOG2_PAGE_SIZE_4K;
174 
175 	if (pvr_obj->flags & PVR_BO_FW_FLAGS_DEVICE_UNCACHED)
176 		cache_policy = ROGUE_MIPSFW_UNCACHED_CACHE_POLICY;
177 	else
178 		cache_policy = mips_data->cache_policy;
179 
180 	pte_flags = get_mips_pte_flags(true, true, cache_policy);
181 
182 	for (pfn = start_pfn; pfn <= end_pfn; pfn++) {
183 		dma_addr_t dma_addr;
184 		u32 pte;
185 
186 		err = pvr_fw_object_get_dma_addr(fw_obj,
187 						 (pfn - start_pfn) <<
188 						 ROGUE_MIPSFW_LOG2_PAGE_SIZE_4K,
189 						 &dma_addr);
190 		if (err)
191 			goto err_unmap_pages;
192 
193 		pte = ((dma_addr >> ROGUE_MIPSFW_LOG2_PAGE_SIZE_4K)
194 		       << ROGUE_MIPSFW_ENTRYLO_PFN_SHIFT) & mips_data->pfn_mask;
195 		pte |= pte_flags;
196 
197 		WRITE_ONCE(mips_data->pt[pfn], pte);
198 	}
199 
200 	pvr_mmu_flush_request_all(pvr_dev);
201 
202 	return 0;
203 
204 err_unmap_pages:
205 	while (--pfn >= start_pfn)
206 		WRITE_ONCE(mips_data->pt[pfn], 0);
207 
208 	pvr_mmu_flush_request_all(pvr_dev);
209 	WARN_ON(pvr_mmu_flush_exec(pvr_dev, true));
210 
211 	return err;
212 }
213 
214 /**
215  * pvr_vm_mips_unmap() - Unmap a FW object into MIPS address space
216  * @pvr_dev: Target PowerVR device.
217  * @fw_obj: FW object to unmap.
218  */
219 void
220 pvr_vm_mips_unmap(struct pvr_device *pvr_dev, struct pvr_fw_object *fw_obj)
221 {
222 	struct pvr_fw_device *fw_dev = &pvr_dev->fw_dev;
223 	struct pvr_fw_mips_data *mips_data = fw_dev->processor_data.mips_data;
224 	const u64 start = fw_obj->fw_mm_node.start;
225 	const u64 size = fw_obj->fw_mm_node.size;
226 	const u64 end = start + size;
227 
228 	const u32 start_pfn = (start & fw_dev->fw_heap_info.offset_mask) >>
229 			      ROGUE_MIPSFW_LOG2_PAGE_SIZE_4K;
230 	const u32 end_pfn = (end & fw_dev->fw_heap_info.offset_mask) >>
231 			    ROGUE_MIPSFW_LOG2_PAGE_SIZE_4K;
232 
233 	for (u32 pfn = start_pfn; pfn < end_pfn; pfn++)
234 		WRITE_ONCE(mips_data->pt[pfn], 0);
235 
236 	pvr_mmu_flush_request_all(pvr_dev);
237 	WARN_ON(pvr_mmu_flush_exec(pvr_dev, true));
238 }
239