1 /*
2  * OPAL IMC interface detection driver
3  * Supported on POWERNV platform
4  *
5  * Copyright	(C) 2017 Madhavan Srinivasan, IBM Corporation.
6  *		(C) 2017 Anju T Sudhakar, IBM Corporation.
7  *		(C) 2017 Hemant K Shaw, IBM Corporation.
8  *
9  * This program is free software; you can redistribute it and/or
10  * modify it under the terms of the GNU General Public License
11  * as published by the Free Software Foundation; either version
12  * 2 of the License, or later version.
13  */
14 #include <linux/kernel.h>
15 #include <linux/platform_device.h>
16 #include <linux/of.h>
17 #include <linux/of_address.h>
18 #include <linux/of_platform.h>
19 #include <linux/crash_dump.h>
20 #include <asm/opal.h>
21 #include <asm/io.h>
22 #include <asm/imc-pmu.h>
23 #include <asm/cputhreads.h>
24 
25 /*
26  * imc_get_mem_addr_nest: Function to get nest counter memory region
27  * for each chip
28  */
29 static int imc_get_mem_addr_nest(struct device_node *node,
30 				 struct imc_pmu *pmu_ptr,
31 				 u32 offset)
32 {
33 	int nr_chips = 0, i;
34 	u64 *base_addr_arr, baddr;
35 	u32 *chipid_arr;
36 
37 	nr_chips = of_property_count_u32_elems(node, "chip-id");
38 	if (nr_chips <= 0)
39 		return -ENODEV;
40 
41 	base_addr_arr = kcalloc(nr_chips, sizeof(u64), GFP_KERNEL);
42 	if (!base_addr_arr)
43 		return -ENOMEM;
44 
45 	chipid_arr = kcalloc(nr_chips, sizeof(u32), GFP_KERNEL);
46 	if (!chipid_arr)
47 		return -ENOMEM;
48 
49 	if (of_property_read_u32_array(node, "chip-id", chipid_arr, nr_chips))
50 		goto error;
51 
52 	if (of_property_read_u64_array(node, "base-addr", base_addr_arr,
53 								nr_chips))
54 		goto error;
55 
56 	pmu_ptr->mem_info = kcalloc(nr_chips, sizeof(struct imc_mem_info),
57 								GFP_KERNEL);
58 	if (!pmu_ptr->mem_info)
59 		goto error;
60 
61 	for (i = 0; i < nr_chips; i++) {
62 		pmu_ptr->mem_info[i].id = chipid_arr[i];
63 		baddr = base_addr_arr[i] + offset;
64 		pmu_ptr->mem_info[i].vbase = phys_to_virt(baddr);
65 	}
66 
67 	pmu_ptr->imc_counter_mmaped = true;
68 	kfree(base_addr_arr);
69 	kfree(chipid_arr);
70 	return 0;
71 
72 error:
73 	kfree(pmu_ptr->mem_info);
74 	kfree(base_addr_arr);
75 	kfree(chipid_arr);
76 	return -1;
77 }
78 
79 /*
80  * imc_pmu_create : Takes the parent device which is the pmu unit, pmu_index
81  *		    and domain as the inputs.
82  * Allocates memory for the struct imc_pmu, sets up its domain, size and offsets
83  */
84 static int imc_pmu_create(struct device_node *parent, int pmu_index, int domain)
85 {
86 	int ret = 0;
87 	struct imc_pmu *pmu_ptr;
88 	u32 offset;
89 
90 	/* memory for pmu */
91 	pmu_ptr = kzalloc(sizeof(struct imc_pmu), GFP_KERNEL);
92 	if (!pmu_ptr)
93 		return -ENOMEM;
94 
95 	/* Set the domain */
96 	pmu_ptr->domain = domain;
97 
98 	ret = of_property_read_u32(parent, "size", &pmu_ptr->counter_mem_size);
99 	if (ret) {
100 		ret = -EINVAL;
101 		goto free_pmu;
102 	}
103 
104 	if (!of_property_read_u32(parent, "offset", &offset)) {
105 		if (imc_get_mem_addr_nest(parent, pmu_ptr, offset)) {
106 			ret = -EINVAL;
107 			goto free_pmu;
108 		}
109 	}
110 
111 	/* Function to register IMC pmu */
112 	ret = init_imc_pmu(parent, pmu_ptr, pmu_index);
113 	if (ret)
114 		pr_err("IMC PMU %s Register failed\n", pmu_ptr->pmu.name);
115 
116 	return 0;
117 
118 free_pmu:
119 	kfree(pmu_ptr);
120 	return ret;
121 }
122 
123 static void disable_nest_pmu_counters(void)
124 {
125 	int nid, cpu;
126 	const struct cpumask *l_cpumask;
127 
128 	get_online_cpus();
129 	for_each_online_node(nid) {
130 		l_cpumask = cpumask_of_node(nid);
131 		cpu = cpumask_first(l_cpumask);
132 		opal_imc_counters_stop(OPAL_IMC_COUNTERS_NEST,
133 				       get_hard_smp_processor_id(cpu));
134 	}
135 	put_online_cpus();
136 }
137 
138 static void disable_core_pmu_counters(void)
139 {
140 	cpumask_t cores_map;
141 	int cpu, rc;
142 
143 	get_online_cpus();
144 	/* Disable the IMC Core functions */
145 	cores_map = cpu_online_cores_map();
146 	for_each_cpu(cpu, &cores_map) {
147 		rc = opal_imc_counters_stop(OPAL_IMC_COUNTERS_CORE,
148 					    get_hard_smp_processor_id(cpu));
149 		if (rc)
150 			pr_err("%s: Failed to stop Core (cpu = %d)\n",
151 				__FUNCTION__, cpu);
152 	}
153 	put_online_cpus();
154 }
155 
156 int get_max_nest_dev(void)
157 {
158 	struct device_node *node;
159 	u32 pmu_units = 0, type;
160 
161 	for_each_compatible_node(node, NULL, IMC_DTB_UNIT_COMPAT) {
162 		if (of_property_read_u32(node, "type", &type))
163 			continue;
164 
165 		if (type == IMC_TYPE_CHIP)
166 			pmu_units++;
167 	}
168 
169 	return pmu_units;
170 }
171 
172 static int opal_imc_counters_probe(struct platform_device *pdev)
173 {
174 	struct device_node *imc_dev = pdev->dev.of_node;
175 	int pmu_count = 0, domain;
176 	u32 type;
177 
178 	/*
179 	 * Check whether this is kdump kernel. If yes, force the engines to
180 	 * stop and return.
181 	 */
182 	if (is_kdump_kernel()) {
183 		disable_nest_pmu_counters();
184 		disable_core_pmu_counters();
185 		return -ENODEV;
186 	}
187 
188 	for_each_compatible_node(imc_dev, NULL, IMC_DTB_UNIT_COMPAT) {
189 		if (of_property_read_u32(imc_dev, "type", &type)) {
190 			pr_warn("IMC Device without type property\n");
191 			continue;
192 		}
193 
194 		switch (type) {
195 		case IMC_TYPE_CHIP:
196 			domain = IMC_DOMAIN_NEST;
197 			break;
198 		case IMC_TYPE_CORE:
199 			domain =IMC_DOMAIN_CORE;
200 			break;
201 		case IMC_TYPE_THREAD:
202 			domain = IMC_DOMAIN_THREAD;
203 			break;
204 		default:
205 			pr_warn("IMC Unknown Device type \n");
206 			domain = -1;
207 			break;
208 		}
209 
210 		if (!imc_pmu_create(imc_dev, pmu_count, domain)) {
211 			if (domain == IMC_DOMAIN_NEST)
212 				pmu_count++;
213 		}
214 	}
215 
216 	return 0;
217 }
218 
219 static void opal_imc_counters_shutdown(struct platform_device *pdev)
220 {
221 	/*
222 	 * Function only stops the engines which is bare minimum.
223 	 * TODO: Need to handle proper memory cleanup and pmu
224 	 * unregister.
225 	 */
226 	disable_nest_pmu_counters();
227 	disable_core_pmu_counters();
228 }
229 
230 static const struct of_device_id opal_imc_match[] = {
231 	{ .compatible = IMC_DTB_COMPAT },
232 	{},
233 };
234 
235 static struct platform_driver opal_imc_driver = {
236 	.driver = {
237 		.name = "opal-imc-counters",
238 		.of_match_table = opal_imc_match,
239 	},
240 	.probe = opal_imc_counters_probe,
241 	.shutdown = opal_imc_counters_shutdown,
242 };
243 
244 builtin_platform_driver(opal_imc_driver);
245