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Commit | Line | Data |
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009f1315 | 1 | /* |
e12f12ac TP |
2 | * Coherency fabric (Aurora) support for Armada 370, 375, 38x and XP |
3 | * platforms. | |
009f1315 GC |
4 | * |
5 | * Copyright (C) 2012 Marvell | |
6 | * | |
7 | * Yehuda Yitschak <yehuday@marvell.com> | |
8 | * Gregory Clement <gregory.clement@free-electrons.com> | |
9 | * Thomas Petazzoni <thomas.petazzoni@free-electrons.com> | |
10 | * | |
11 | * This file is licensed under the terms of the GNU General Public | |
12 | * License version 2. This program is licensed "as is" without any | |
13 | * warranty of any kind, whether express or implied. | |
14 | * | |
e12f12ac | 15 | * The Armada 370, 375, 38x and XP SOCs have a coherency fabric which is |
009f1315 GC |
16 | * responsible for ensuring hardware coherency between all CPUs and between |
17 | * CPUs and I/O masters. This file initializes the coherency fabric and | |
18 | * supplies basic routines for configuring and controlling hardware coherency | |
19 | */ | |
20 | ||
5ab5afd8 TP |
21 | #define pr_fmt(fmt) "mvebu-coherency: " fmt |
22 | ||
009f1315 GC |
23 | #include <linux/kernel.h> |
24 | #include <linux/init.h> | |
25 | #include <linux/of_address.h> | |
26 | #include <linux/io.h> | |
27 | #include <linux/smp.h> | |
e60304f8 GC |
28 | #include <linux/dma-mapping.h> |
29 | #include <linux/platform_device.h> | |
5ab5afd8 TP |
30 | #include <linux/slab.h> |
31 | #include <linux/mbus.h> | |
b0063aad | 32 | #include <linux/pci.h> |
009f1315 | 33 | #include <asm/smp_plat.h> |
580ff0ee | 34 | #include <asm/cacheflush.h> |
497a9230 | 35 | #include <asm/mach/map.h> |
b12634e3 | 36 | #include "coherency.h" |
39438567 | 37 | #include "mvebu-soc-id.h" |
009f1315 | 38 | |
8bd26e3a | 39 | unsigned long coherency_phys_base; |
ccd6a131 | 40 | void __iomem *coherency_base; |
e60304f8 | 41 | static void __iomem *coherency_cpu_base; |
009f1315 GC |
42 | |
43 | /* Coherency fabric registers */ | |
e60304f8 GC |
44 | #define IO_SYNC_BARRIER_CTL_OFFSET 0x0 |
45 | ||
924d38f4 | 46 | enum { |
501f928e | 47 | COHERENCY_FABRIC_TYPE_NONE, |
924d38f4 | 48 | COHERENCY_FABRIC_TYPE_ARMADA_370_XP, |
77fa4b9a | 49 | COHERENCY_FABRIC_TYPE_ARMADA_375, |
d0de9323 | 50 | COHERENCY_FABRIC_TYPE_ARMADA_380, |
924d38f4 TP |
51 | }; |
52 | ||
009f1315 | 53 | static struct of_device_id of_coherency_table[] = { |
924d38f4 TP |
54 | {.compatible = "marvell,coherency-fabric", |
55 | .data = (void *) COHERENCY_FABRIC_TYPE_ARMADA_370_XP }, | |
77fa4b9a TP |
56 | {.compatible = "marvell,armada-375-coherency-fabric", |
57 | .data = (void *) COHERENCY_FABRIC_TYPE_ARMADA_375 }, | |
d0de9323 TP |
58 | {.compatible = "marvell,armada-380-coherency-fabric", |
59 | .data = (void *) COHERENCY_FABRIC_TYPE_ARMADA_380 }, | |
009f1315 GC |
60 | { /* end of list */ }, |
61 | }; | |
62 | ||
2e8a5942 GC |
63 | /* Functions defined in coherency_ll.S */ |
64 | int ll_enable_coherency(void); | |
65 | void ll_add_cpu_to_smp_group(void); | |
009f1315 | 66 | |
952f4ca7 | 67 | int set_cpu_coherent(void) |
009f1315 GC |
68 | { |
69 | if (!coherency_base) { | |
b41375f7 | 70 | pr_warn("Can't make current CPU cache coherent.\n"); |
009f1315 GC |
71 | pr_warn("Coherency fabric is not initialized\n"); |
72 | return 1; | |
73 | } | |
74 | ||
2e8a5942 GC |
75 | ll_add_cpu_to_smp_group(); |
76 | return ll_enable_coherency(); | |
009f1315 GC |
77 | } |
78 | ||
e60304f8 GC |
79 | static inline void mvebu_hwcc_sync_io_barrier(void) |
80 | { | |
81 | writel(0x1, coherency_cpu_base + IO_SYNC_BARRIER_CTL_OFFSET); | |
82 | while (readl(coherency_cpu_base + IO_SYNC_BARRIER_CTL_OFFSET) & 0x1); | |
83 | } | |
84 | ||
85 | static dma_addr_t mvebu_hwcc_dma_map_page(struct device *dev, struct page *page, | |
86 | unsigned long offset, size_t size, | |
87 | enum dma_data_direction dir, | |
88 | struct dma_attrs *attrs) | |
89 | { | |
90 | if (dir != DMA_TO_DEVICE) | |
91 | mvebu_hwcc_sync_io_barrier(); | |
92 | return pfn_to_dma(dev, page_to_pfn(page)) + offset; | |
93 | } | |
94 | ||
95 | ||
96 | static void mvebu_hwcc_dma_unmap_page(struct device *dev, dma_addr_t dma_handle, | |
97 | size_t size, enum dma_data_direction dir, | |
98 | struct dma_attrs *attrs) | |
99 | { | |
100 | if (dir != DMA_TO_DEVICE) | |
101 | mvebu_hwcc_sync_io_barrier(); | |
102 | } | |
103 | ||
104 | static void mvebu_hwcc_dma_sync(struct device *dev, dma_addr_t dma_handle, | |
105 | size_t size, enum dma_data_direction dir) | |
106 | { | |
107 | if (dir != DMA_TO_DEVICE) | |
108 | mvebu_hwcc_sync_io_barrier(); | |
109 | } | |
110 | ||
111 | static struct dma_map_ops mvebu_hwcc_dma_ops = { | |
112 | .alloc = arm_dma_alloc, | |
113 | .free = arm_dma_free, | |
114 | .mmap = arm_dma_mmap, | |
115 | .map_page = mvebu_hwcc_dma_map_page, | |
116 | .unmap_page = mvebu_hwcc_dma_unmap_page, | |
117 | .get_sgtable = arm_dma_get_sgtable, | |
118 | .map_sg = arm_dma_map_sg, | |
119 | .unmap_sg = arm_dma_unmap_sg, | |
120 | .sync_single_for_cpu = mvebu_hwcc_dma_sync, | |
121 | .sync_single_for_device = mvebu_hwcc_dma_sync, | |
122 | .sync_sg_for_cpu = arm_dma_sync_sg_for_cpu, | |
123 | .sync_sg_for_device = arm_dma_sync_sg_for_device, | |
124 | .set_dma_mask = arm_dma_set_mask, | |
125 | }; | |
126 | ||
b0063aad TP |
127 | static int mvebu_hwcc_notifier(struct notifier_block *nb, |
128 | unsigned long event, void *__dev) | |
e60304f8 GC |
129 | { |
130 | struct device *dev = __dev; | |
131 | ||
132 | if (event != BUS_NOTIFY_ADD_DEVICE) | |
133 | return NOTIFY_DONE; | |
134 | set_dma_ops(dev, &mvebu_hwcc_dma_ops); | |
135 | ||
136 | return NOTIFY_OK; | |
137 | } | |
138 | ||
b0063aad TP |
139 | static struct notifier_block mvebu_hwcc_nb = { |
140 | .notifier_call = mvebu_hwcc_notifier, | |
e60304f8 GC |
141 | }; |
142 | ||
a728b977 EG |
143 | static struct notifier_block mvebu_hwcc_pci_nb = { |
144 | .notifier_call = mvebu_hwcc_notifier, | |
145 | }; | |
146 | ||
924d38f4 TP |
147 | static void __init armada_370_coherency_init(struct device_node *np) |
148 | { | |
149 | struct resource res; | |
150 | ||
151 | of_address_to_resource(np, 0, &res); | |
152 | coherency_phys_base = res.start; | |
153 | /* | |
154 | * Ensure secondary CPUs will see the updated value, | |
155 | * which they read before they join the coherency | |
156 | * fabric, and therefore before they are coherent with | |
157 | * the boot CPU cache. | |
158 | */ | |
159 | sync_cache_w(&coherency_phys_base); | |
160 | coherency_base = of_iomap(np, 0); | |
161 | coherency_cpu_base = of_iomap(np, 1); | |
952f4ca7 | 162 | set_cpu_coherent(); |
924d38f4 TP |
163 | } |
164 | ||
497a9230 TP |
165 | /* |
166 | * This ioremap hook is used on Armada 375/38x to ensure that PCIe | |
167 | * memory areas are mapped as MT_UNCACHED instead of MT_DEVICE. This | |
168 | * is needed as a workaround for a deadlock issue between the PCIe | |
169 | * interface and the cache controller. | |
170 | */ | |
171 | static void __iomem * | |
172 | armada_pcie_wa_ioremap_caller(phys_addr_t phys_addr, size_t size, | |
173 | unsigned int mtype, void *caller) | |
174 | { | |
175 | struct resource pcie_mem; | |
176 | ||
177 | mvebu_mbus_get_pcie_mem_aperture(&pcie_mem); | |
178 | ||
179 | if (pcie_mem.start <= phys_addr && (phys_addr + size) <= pcie_mem.end) | |
180 | mtype = MT_UNCACHED; | |
181 | ||
182 | return __arm_ioremap_caller(phys_addr, size, mtype, caller); | |
183 | } | |
184 | ||
d0de9323 | 185 | static void __init armada_375_380_coherency_init(struct device_node *np) |
77fa4b9a | 186 | { |
497a9230 TP |
187 | struct device_node *cache_dn; |
188 | ||
77fa4b9a | 189 | coherency_cpu_base = of_iomap(np, 0); |
497a9230 TP |
190 | arch_ioremap_caller = armada_pcie_wa_ioremap_caller; |
191 | ||
dcad6887 TP |
192 | /* |
193 | * We should switch the PL310 to I/O coherency mode only if | |
194 | * I/O coherency is actually enabled. | |
195 | */ | |
196 | if (!coherency_available()) | |
197 | return; | |
198 | ||
497a9230 TP |
199 | /* |
200 | * Add the PL310 property "arm,io-coherent". This makes sure the | |
201 | * outer sync operation is not used, which allows to | |
202 | * workaround the system erratum that causes deadlocks when | |
203 | * doing PCIe in an SMP situation on Armada 375 and Armada | |
204 | * 38x. | |
205 | */ | |
206 | for_each_compatible_node(cache_dn, NULL, "arm,pl310-cache") { | |
207 | struct property *p; | |
208 | ||
209 | p = kzalloc(sizeof(*p), GFP_KERNEL); | |
210 | p->name = kstrdup("arm,io-coherent", GFP_KERNEL); | |
211 | of_add_property(cache_dn, p); | |
212 | } | |
77fa4b9a TP |
213 | } |
214 | ||
501f928e | 215 | static int coherency_type(void) |
009f1315 GC |
216 | { |
217 | struct device_node *np; | |
5fbba080 | 218 | const struct of_device_id *match; |
e5535545 | 219 | int type; |
009f1315 | 220 | |
e5535545 TP |
221 | /* |
222 | * The coherency fabric is needed: | |
223 | * - For coherency between processors on Armada XP, so only | |
224 | * when SMP is enabled. | |
225 | * - For coherency between the processor and I/O devices, but | |
226 | * this coherency requires many pre-requisites (write | |
227 | * allocate cache policy, shareable pages, SMP bit set) that | |
228 | * are only meant in SMP situations. | |
229 | * | |
230 | * Note that this means that on Armada 370, there is currently | |
231 | * no way to use hardware I/O coherency, because even when | |
232 | * CONFIG_SMP is enabled, is_smp() returns false due to the | |
233 | * Armada 370 being a single-core processor. To lift this | |
234 | * limitation, we would have to find a way to make the cache | |
235 | * policy set to write-allocate (on all Armada SoCs), and to | |
236 | * set the shareable attribute in page tables (on all Armada | |
237 | * SoCs except the Armada 370). Unfortunately, such decisions | |
238 | * are taken very early in the kernel boot process, at a point | |
239 | * where we don't know yet on which SoC we are running. | |
240 | ||
241 | */ | |
242 | if (!is_smp()) | |
243 | return COHERENCY_FABRIC_TYPE_NONE; | |
924d38f4 | 244 | |
e5535545 TP |
245 | np = of_find_matching_node_and_match(NULL, of_coherency_table, &match); |
246 | if (!np) | |
247 | return COHERENCY_FABRIC_TYPE_NONE; | |
924d38f4 | 248 | |
e5535545 | 249 | type = (int) match->data; |
77fa4b9a | 250 | |
e5535545 | 251 | of_node_put(np); |
009f1315 | 252 | |
e5535545 | 253 | return type; |
009f1315 | 254 | } |
865e0527 | 255 | |
8f1e8ee2 TP |
256 | /* |
257 | * As a precaution, we currently completely disable hardware I/O | |
258 | * coherency, until enough testing is done with automatic I/O | |
259 | * synchronization barriers to validate that it is a proper solution. | |
260 | */ | |
501f928e | 261 | int coherency_available(void) |
865e0527 | 262 | { |
8f1e8ee2 | 263 | return false; |
501f928e TP |
264 | } |
265 | ||
266 | int __init coherency_init(void) | |
267 | { | |
268 | int type = coherency_type(); | |
abe511ac JZ |
269 | struct device_node *np; |
270 | ||
271 | np = of_find_matching_node(NULL, of_coherency_table); | |
501f928e TP |
272 | |
273 | if (type == COHERENCY_FABRIC_TYPE_ARMADA_370_XP) | |
274 | armada_370_coherency_init(np); | |
d0de9323 TP |
275 | else if (type == COHERENCY_FABRIC_TYPE_ARMADA_375 || |
276 | type == COHERENCY_FABRIC_TYPE_ARMADA_380) | |
277 | armada_375_380_coherency_init(np); | |
501f928e | 278 | |
2eb04ae0 TP |
279 | of_node_put(np); |
280 | ||
501f928e TP |
281 | return 0; |
282 | } | |
283 | ||
284 | static int __init coherency_late_init(void) | |
285 | { | |
ef01c6c3 TP |
286 | if (coherency_available()) |
287 | bus_register_notifier(&platform_bus_type, | |
288 | &mvebu_hwcc_nb); | |
865e0527 TP |
289 | return 0; |
290 | } | |
291 | ||
292 | postcore_initcall(coherency_late_init); | |
b0063aad | 293 | |
8828ccc3 | 294 | #if IS_ENABLED(CONFIG_PCI) |
b0063aad TP |
295 | static int __init coherency_pci_init(void) |
296 | { | |
297 | if (coherency_available()) | |
298 | bus_register_notifier(&pci_bus_type, | |
a728b977 | 299 | &mvebu_hwcc_pci_nb); |
b0063aad TP |
300 | return 0; |
301 | } | |
302 | ||
303 | arch_initcall(coherency_pci_init); | |
8828ccc3 | 304 | #endif |