1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * OPAL IMC interface detection driver
4  * Supported on POWERNV platform
5  *
6  * Copyright	(C) 2017 Madhavan Srinivasan, IBM Corporation.
7  *		(C) 2017 Anju T Sudhakar, IBM Corporation.
8  *		(C) 2017 Hemant K Shaw, IBM Corporation.
9  */
10 #include <linux/kernel.h>
11 #include <linux/platform_device.h>
12 #include <linux/of.h>
13 #include <linux/of_address.h>
14 #include <linux/of_platform.h>
15 #include <linux/crash_dump.h>
16 #include <linux/debugfs.h>
17 #include <asm/opal.h>
18 #include <asm/io.h>
19 #include <asm/imc-pmu.h>
20 #include <asm/cputhreads.h>
21 
22 static struct dentry *imc_debugfs_parent;
23 
24 /* Helpers to export imc command and mode via debugfs */
imc_mem_get(void * data,u64 * val)25 static int imc_mem_get(void *data, u64 *val)
26 {
27 	*val = cpu_to_be64(*(u64 *)data);
28 	return 0;
29 }
30 
imc_mem_set(void * data,u64 val)31 static int imc_mem_set(void *data, u64 val)
32 {
33 	*(u64 *)data = cpu_to_be64(val);
34 	return 0;
35 }
36 DEFINE_DEBUGFS_ATTRIBUTE(fops_imc_x64, imc_mem_get, imc_mem_set, "0x%016llx\n");
37 
imc_debugfs_create_x64(const char * name,umode_t mode,struct dentry * parent,u64 * value)38 static void imc_debugfs_create_x64(const char *name, umode_t mode,
39 				   struct dentry *parent, u64  *value)
40 {
41 	debugfs_create_file_unsafe(name, mode, parent, value, &fops_imc_x64);
42 }
43 
44 /*
45  * export_imc_mode_and_cmd: Create a debugfs interface
46  *                     for imc_cmd and imc_mode
47  *                     for each node in the system.
48  *  imc_mode and imc_cmd can be changed by echo into
49  *  this interface.
50  */
export_imc_mode_and_cmd(struct device_node * node,struct imc_pmu * pmu_ptr)51 static void export_imc_mode_and_cmd(struct device_node *node,
52 				    struct imc_pmu *pmu_ptr)
53 {
54 	static u64 loc, *imc_mode_addr, *imc_cmd_addr;
55 	char mode[16], cmd[16];
56 	u32 cb_offset;
57 	struct imc_mem_info *ptr = pmu_ptr->mem_info;
58 
59 	imc_debugfs_parent = debugfs_create_dir("imc", arch_debugfs_dir);
60 
61 	if (of_property_read_u32(node, "cb_offset", &cb_offset))
62 		cb_offset = IMC_CNTL_BLK_OFFSET;
63 
64 	while (ptr->vbase != NULL) {
65 		loc = (u64)(ptr->vbase) + cb_offset;
66 		imc_mode_addr = (u64 *)(loc + IMC_CNTL_BLK_MODE_OFFSET);
67 		sprintf(mode, "imc_mode_%d", (u32)(ptr->id));
68 		imc_debugfs_create_x64(mode, 0600, imc_debugfs_parent,
69 				       imc_mode_addr);
70 
71 		imc_cmd_addr = (u64 *)(loc + IMC_CNTL_BLK_CMD_OFFSET);
72 		sprintf(cmd, "imc_cmd_%d", (u32)(ptr->id));
73 		imc_debugfs_create_x64(cmd, 0600, imc_debugfs_parent,
74 				       imc_cmd_addr);
75 		ptr++;
76 	}
77 }
78 
79 /*
80  * imc_get_mem_addr_nest: Function to get nest counter memory region
81  * for each chip
82  */
imc_get_mem_addr_nest(struct device_node * node,struct imc_pmu * pmu_ptr,u32 offset)83 static int imc_get_mem_addr_nest(struct device_node *node,
84 				 struct imc_pmu *pmu_ptr,
85 				 u32 offset)
86 {
87 	int nr_chips = 0, i;
88 	u64 *base_addr_arr, baddr;
89 	u32 *chipid_arr;
90 
91 	nr_chips = of_property_count_u32_elems(node, "chip-id");
92 	if (nr_chips <= 0)
93 		return -ENODEV;
94 
95 	base_addr_arr = kcalloc(nr_chips, sizeof(*base_addr_arr), GFP_KERNEL);
96 	if (!base_addr_arr)
97 		return -ENOMEM;
98 
99 	chipid_arr = kcalloc(nr_chips, sizeof(*chipid_arr), GFP_KERNEL);
100 	if (!chipid_arr) {
101 		kfree(base_addr_arr);
102 		return -ENOMEM;
103 	}
104 
105 	if (of_property_read_u32_array(node, "chip-id", chipid_arr, nr_chips))
106 		goto error;
107 
108 	if (of_property_read_u64_array(node, "base-addr", base_addr_arr,
109 								nr_chips))
110 		goto error;
111 
112 	pmu_ptr->mem_info = kcalloc(nr_chips + 1, sizeof(*pmu_ptr->mem_info),
113 				    GFP_KERNEL);
114 	if (!pmu_ptr->mem_info)
115 		goto error;
116 
117 	for (i = 0; i < nr_chips; i++) {
118 		pmu_ptr->mem_info[i].id = chipid_arr[i];
119 		baddr = base_addr_arr[i] + offset;
120 		pmu_ptr->mem_info[i].vbase = phys_to_virt(baddr);
121 	}
122 
123 	pmu_ptr->imc_counter_mmaped = true;
124 	kfree(base_addr_arr);
125 	kfree(chipid_arr);
126 	return 0;
127 
128 error:
129 	kfree(base_addr_arr);
130 	kfree(chipid_arr);
131 	return -1;
132 }
133 
134 /*
135  * imc_pmu_create : Takes the parent device which is the pmu unit, pmu_index
136  *		    and domain as the inputs.
137  * Allocates memory for the struct imc_pmu, sets up its domain, size and offsets
138  */
imc_pmu_create(struct device_node * parent,int pmu_index,int domain)139 static struct imc_pmu *imc_pmu_create(struct device_node *parent, int pmu_index, int domain)
140 {
141 	int ret = 0;
142 	struct imc_pmu *pmu_ptr;
143 	u32 offset;
144 
145 	/* Return for unknown domain */
146 	if (domain < 0)
147 		return NULL;
148 
149 	/* memory for pmu */
150 	pmu_ptr = kzalloc(sizeof(*pmu_ptr), GFP_KERNEL);
151 	if (!pmu_ptr)
152 		return NULL;
153 
154 	/* Set the domain */
155 	pmu_ptr->domain = domain;
156 
157 	ret = of_property_read_u32(parent, "size", &pmu_ptr->counter_mem_size);
158 	if (ret)
159 		goto free_pmu;
160 
161 	if (!of_property_read_u32(parent, "offset", &offset)) {
162 		if (imc_get_mem_addr_nest(parent, pmu_ptr, offset))
163 			goto free_pmu;
164 	}
165 
166 	/* Function to register IMC pmu */
167 	ret = init_imc_pmu(parent, pmu_ptr, pmu_index);
168 	if (ret) {
169 		pr_err("IMC PMU %s Register failed\n", pmu_ptr->pmu.name);
170 		kfree(pmu_ptr->pmu.name);
171 		if (pmu_ptr->domain == IMC_DOMAIN_NEST)
172 			kfree(pmu_ptr->mem_info);
173 		kfree(pmu_ptr);
174 		return NULL;
175 	}
176 
177 	return pmu_ptr;
178 
179 free_pmu:
180 	kfree(pmu_ptr);
181 	return NULL;
182 }
183 
disable_nest_pmu_counters(void)184 static void disable_nest_pmu_counters(void)
185 {
186 	int nid, cpu;
187 	const struct cpumask *l_cpumask;
188 
189 	cpus_read_lock();
190 	for_each_node_with_cpus(nid) {
191 		l_cpumask = cpumask_of_node(nid);
192 		cpu = cpumask_first_and(l_cpumask, cpu_online_mask);
193 		if (cpu >= nr_cpu_ids)
194 			continue;
195 		opal_imc_counters_stop(OPAL_IMC_COUNTERS_NEST,
196 				       get_hard_smp_processor_id(cpu));
197 	}
198 	cpus_read_unlock();
199 }
200 
disable_core_pmu_counters(void)201 static void disable_core_pmu_counters(void)
202 {
203 	int cpu, rc;
204 
205 	cpus_read_lock();
206 	/* Disable the IMC Core functions */
207 	for_each_online_cpu(cpu) {
208 		if (cpu_first_thread_sibling(cpu) != cpu)
209 			continue;
210 		rc = opal_imc_counters_stop(OPAL_IMC_COUNTERS_CORE,
211 					    get_hard_smp_processor_id(cpu));
212 		if (rc)
213 			pr_err("%s: Failed to stop Core (cpu = %d)\n",
214 				__func__, cpu);
215 	}
216 	cpus_read_unlock();
217 }
218 
get_max_nest_dev(void)219 int get_max_nest_dev(void)
220 {
221 	struct device_node *node;
222 	u32 pmu_units = 0, type;
223 
224 	for_each_compatible_node(node, NULL, IMC_DTB_UNIT_COMPAT) {
225 		if (of_property_read_u32(node, "type", &type))
226 			continue;
227 
228 		if (type == IMC_TYPE_CHIP)
229 			pmu_units++;
230 	}
231 
232 	return pmu_units;
233 }
234 
opal_imc_counters_probe(struct platform_device * pdev)235 static int opal_imc_counters_probe(struct platform_device *pdev)
236 {
237 	struct device_node *imc_dev = pdev->dev.of_node;
238 	struct imc_pmu *pmu;
239 	int pmu_count = 0, domain;
240 	bool core_imc_reg = false, thread_imc_reg = false;
241 	u32 type;
242 
243 	/*
244 	 * Check whether this is kdump kernel. If yes, force the engines to
245 	 * stop and return.
246 	 */
247 	if (is_kdump_kernel()) {
248 		disable_nest_pmu_counters();
249 		disable_core_pmu_counters();
250 		return -ENODEV;
251 	}
252 
253 	for_each_compatible_node(imc_dev, NULL, IMC_DTB_UNIT_COMPAT) {
254 		pmu = NULL;
255 		if (of_property_read_u32(imc_dev, "type", &type)) {
256 			pr_warn("IMC Device without type property\n");
257 			continue;
258 		}
259 
260 		switch (type) {
261 		case IMC_TYPE_CHIP:
262 			domain = IMC_DOMAIN_NEST;
263 			break;
264 		case IMC_TYPE_CORE:
265 			domain =IMC_DOMAIN_CORE;
266 			break;
267 		case IMC_TYPE_THREAD:
268 			domain = IMC_DOMAIN_THREAD;
269 			break;
270 		case IMC_TYPE_TRACE:
271 			domain = IMC_DOMAIN_TRACE;
272 			break;
273 		default:
274 			pr_warn("IMC Unknown Device type \n");
275 			domain = -1;
276 			break;
277 		}
278 
279 		pmu = imc_pmu_create(imc_dev, pmu_count, domain);
280 		if (pmu != NULL) {
281 			if (domain == IMC_DOMAIN_NEST) {
282 				if (!imc_debugfs_parent)
283 					export_imc_mode_and_cmd(imc_dev, pmu);
284 				pmu_count++;
285 			}
286 			if (domain == IMC_DOMAIN_CORE)
287 				core_imc_reg = true;
288 			if (domain == IMC_DOMAIN_THREAD)
289 				thread_imc_reg = true;
290 		}
291 	}
292 
293 	/* If core imc is not registered, unregister thread-imc */
294 	if (!core_imc_reg && thread_imc_reg)
295 		unregister_thread_imc();
296 
297 	return 0;
298 }
299 
opal_imc_counters_shutdown(struct platform_device * pdev)300 static void opal_imc_counters_shutdown(struct platform_device *pdev)
301 {
302 	/*
303 	 * Function only stops the engines which is bare minimum.
304 	 * TODO: Need to handle proper memory cleanup and pmu
305 	 * unregister.
306 	 */
307 	disable_nest_pmu_counters();
308 	disable_core_pmu_counters();
309 }
310 
311 static const struct of_device_id opal_imc_match[] = {
312 	{ .compatible = IMC_DTB_COMPAT },
313 	{},
314 };
315 
316 static struct platform_driver opal_imc_driver = {
317 	.driver = {
318 		.name = "opal-imc-counters",
319 		.of_match_table = opal_imc_match,
320 	},
321 	.probe = opal_imc_counters_probe,
322 	.shutdown = opal_imc_counters_shutdown,
323 };
324 
325 builtin_platform_driver(opal_imc_driver);
326