1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * Driver for HiSilicon Hydra Home Agent (HHA).
4 *
5 * Copyright (c) 2025 HiSilicon Technologies Co., Ltd.
6 * Author: Yicong Yang <yangyicong@hisilicon.com>
7 * Yushan Wang <wangyushan12@huawei.com>
8 *
9 * A system typically contains multiple HHAs. Each is responsible for a subset
10 * of the physical addresses in the system, but interleave can make the mapping
11 * from a particular cache line to a responsible HHA complex. As such no
12 * filtering is done in the driver, with the hardware being responsible for
13 * responding with success for even if it was not responsible for any addresses
14 * in the range on which the operation was requested.
15 */
16
17 #include <linux/bitfield.h>
18 #include <linux/cache_coherency.h>
19 #include <linux/dev_printk.h>
20 #include <linux/init.h>
21 #include <linux/io.h>
22 #include <linux/iopoll.h>
23 #include <linux/kernel.h>
24 #include <linux/memregion.h>
25 #include <linux/module.h>
26 #include <linux/mod_devicetable.h>
27 #include <linux/mutex.h>
28 #include <linux/platform_device.h>
29
30 #define HISI_HHA_CTRL 0x5004
31 #define HISI_HHA_CTRL_EN BIT(0)
32 #define HISI_HHA_CTRL_RANGE BIT(1)
33 #define HISI_HHA_CTRL_TYPE GENMASK(3, 2)
34 #define HISI_HHA_START_L 0x5008
35 #define HISI_HHA_START_H 0x500c
36 #define HISI_HHA_LEN_L 0x5010
37 #define HISI_HHA_LEN_H 0x5014
38
39 /* The maintain operation performs in a 128 Byte granularity */
40 #define HISI_HHA_MAINT_ALIGN 128
41
42 #define HISI_HHA_POLL_GAP_US 10
43 #define HISI_HHA_POLL_TIMEOUT_US 50000
44
45 struct hisi_soc_hha {
46 /* Must be first element */
47 struct cache_coherency_ops_inst cci;
48 /* Locks HHA instance to forbid overlapping access. */
49 struct mutex lock;
50 void __iomem *base;
51 };
52
hisi_hha_cache_maintain_wait_finished(struct hisi_soc_hha * soc_hha)53 static bool hisi_hha_cache_maintain_wait_finished(struct hisi_soc_hha *soc_hha)
54 {
55 u32 val;
56
57 return !readl_poll_timeout_atomic(soc_hha->base + HISI_HHA_CTRL, val,
58 !(val & HISI_HHA_CTRL_EN),
59 HISI_HHA_POLL_GAP_US,
60 HISI_HHA_POLL_TIMEOUT_US);
61 }
62
hisi_soc_hha_wbinv(struct cache_coherency_ops_inst * cci,struct cc_inval_params * invp)63 static int hisi_soc_hha_wbinv(struct cache_coherency_ops_inst *cci,
64 struct cc_inval_params *invp)
65 {
66 struct hisi_soc_hha *soc_hha =
67 container_of(cci, struct hisi_soc_hha, cci);
68 phys_addr_t top, addr = invp->addr;
69 size_t size = invp->size;
70 u32 reg;
71
72 if (!size)
73 return -EINVAL;
74
75 addr = ALIGN_DOWN(addr, HISI_HHA_MAINT_ALIGN);
76 top = ALIGN(addr + size, HISI_HHA_MAINT_ALIGN);
77 size = top - addr;
78
79 guard(mutex)(&soc_hha->lock);
80
81 if (!hisi_hha_cache_maintain_wait_finished(soc_hha))
82 return -EBUSY;
83
84 /*
85 * Hardware will search for addresses ranging [addr, addr + size - 1],
86 * last byte included, and perform maintenance in 128 byte granules
87 * on those cachelines which contain the addresses. If a given instance
88 * is either not responsible for a cacheline or that cacheline is not
89 * currently present then the search will fail, no operation will be
90 * necessary and the device will report success.
91 */
92 size -= 1;
93
94 writel(lower_32_bits(addr), soc_hha->base + HISI_HHA_START_L);
95 writel(upper_32_bits(addr), soc_hha->base + HISI_HHA_START_H);
96 writel(lower_32_bits(size), soc_hha->base + HISI_HHA_LEN_L);
97 writel(upper_32_bits(size), soc_hha->base + HISI_HHA_LEN_H);
98
99 reg = FIELD_PREP(HISI_HHA_CTRL_TYPE, 1); /* Clean Invalid */
100 reg |= HISI_HHA_CTRL_RANGE | HISI_HHA_CTRL_EN;
101 writel(reg, soc_hha->base + HISI_HHA_CTRL);
102
103 return 0;
104 }
105
hisi_soc_hha_done(struct cache_coherency_ops_inst * cci)106 static int hisi_soc_hha_done(struct cache_coherency_ops_inst *cci)
107 {
108 struct hisi_soc_hha *soc_hha =
109 container_of(cci, struct hisi_soc_hha, cci);
110
111 guard(mutex)(&soc_hha->lock);
112 if (!hisi_hha_cache_maintain_wait_finished(soc_hha))
113 return -ETIMEDOUT;
114
115 return 0;
116 }
117
118 static const struct cache_coherency_ops hha_ops = {
119 .wbinv = hisi_soc_hha_wbinv,
120 .done = hisi_soc_hha_done,
121 };
122
hisi_soc_hha_probe(struct platform_device * pdev)123 static int hisi_soc_hha_probe(struct platform_device *pdev)
124 {
125 struct hisi_soc_hha *soc_hha;
126 struct resource *mem;
127 int ret;
128
129 soc_hha = cache_coherency_ops_instance_alloc(&hha_ops,
130 struct hisi_soc_hha, cci);
131 if (!soc_hha)
132 return -ENOMEM;
133
134 platform_set_drvdata(pdev, soc_hha);
135
136 mutex_init(&soc_hha->lock);
137
138 mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
139 if (!mem) {
140 ret = -ENOMEM;
141 goto err_free_cci;
142 }
143
144 soc_hha->base = ioremap(mem->start, resource_size(mem));
145 if (!soc_hha->base) {
146 ret = dev_err_probe(&pdev->dev, -ENOMEM,
147 "failed to remap io memory");
148 goto err_free_cci;
149 }
150
151 ret = cache_coherency_ops_instance_register(&soc_hha->cci);
152 if (ret)
153 goto err_iounmap;
154
155 return 0;
156
157 err_iounmap:
158 iounmap(soc_hha->base);
159 err_free_cci:
160 cache_coherency_ops_instance_put(&soc_hha->cci);
161 return ret;
162 }
163
hisi_soc_hha_remove(struct platform_device * pdev)164 static void hisi_soc_hha_remove(struct platform_device *pdev)
165 {
166 struct hisi_soc_hha *soc_hha = platform_get_drvdata(pdev);
167
168 cache_coherency_ops_instance_unregister(&soc_hha->cci);
169 iounmap(soc_hha->base);
170 cache_coherency_ops_instance_put(&soc_hha->cci);
171 }
172
173 static const struct acpi_device_id hisi_soc_hha_ids[] = {
174 { "HISI0511", },
175 { }
176 };
177 MODULE_DEVICE_TABLE(acpi, hisi_soc_hha_ids);
178
179 static struct platform_driver hisi_soc_hha_driver = {
180 .driver = {
181 .name = "hisi_soc_hha",
182 .acpi_match_table = hisi_soc_hha_ids,
183 },
184 .probe = hisi_soc_hha_probe,
185 .remove = hisi_soc_hha_remove,
186 };
187
188 module_platform_driver(hisi_soc_hha_driver);
189
190 MODULE_IMPORT_NS("CACHE_COHERENCY");
191 MODULE_DESCRIPTION("HiSilicon Hydra Home Agent driver supporting cache maintenance");
192 MODULE_AUTHOR("Yicong Yang <yangyicong@hisilicon.com>");
193 MODULE_AUTHOR("Yushan Wang <wangyushan12@huawei.com>");
194 MODULE_LICENSE("GPL");
195