xref: /openbmc/linux/drivers/misc/cxl/main.c (revision bc5aa3a0)
1 /*
2  * Copyright 2014 IBM Corp.
3  *
4  * This program is free software; you can redistribute it and/or
5  * modify it under the terms of the GNU General Public License
6  * as published by the Free Software Foundation; either version
7  * 2 of the License, or (at your option) any later version.
8  */
9 
10 #include <linux/spinlock.h>
11 #include <linux/kernel.h>
12 #include <linux/module.h>
13 #include <linux/device.h>
14 #include <linux/mutex.h>
15 #include <linux/init.h>
16 #include <linux/list.h>
17 #include <linux/mm.h>
18 #include <linux/of.h>
19 #include <linux/slab.h>
20 #include <linux/idr.h>
21 #include <linux/pci.h>
22 #include <asm/cputable.h>
23 #include <misc/cxl-base.h>
24 
25 #include "cxl.h"
26 #include "trace.h"
27 
28 static DEFINE_SPINLOCK(adapter_idr_lock);
29 static DEFINE_IDR(cxl_adapter_idr);
30 
31 uint cxl_verbose;
32 module_param_named(verbose, cxl_verbose, uint, 0600);
33 MODULE_PARM_DESC(verbose, "Enable verbose dmesg output");
34 
35 const struct cxl_backend_ops *cxl_ops;
36 
37 int cxl_afu_slbia(struct cxl_afu *afu)
38 {
39 	unsigned long timeout = jiffies + (HZ * CXL_TIMEOUT);
40 
41 	pr_devel("cxl_afu_slbia issuing SLBIA command\n");
42 	cxl_p2n_write(afu, CXL_SLBIA_An, CXL_TLB_SLB_IQ_ALL);
43 	while (cxl_p2n_read(afu, CXL_SLBIA_An) & CXL_TLB_SLB_P) {
44 		if (time_after_eq(jiffies, timeout)) {
45 			dev_warn(&afu->dev, "WARNING: CXL AFU SLBIA timed out!\n");
46 			return -EBUSY;
47 		}
48 		/* If the adapter has gone down, we can assume that we
49 		 * will PERST it and that will invalidate everything.
50 		 */
51 		if (!cxl_ops->link_ok(afu->adapter, afu))
52 			return -EIO;
53 		cpu_relax();
54 	}
55 	return 0;
56 }
57 
58 static inline void _cxl_slbia(struct cxl_context *ctx, struct mm_struct *mm)
59 {
60 	struct task_struct *task;
61 	unsigned long flags;
62 	if (!(task = get_pid_task(ctx->pid, PIDTYPE_PID))) {
63 		pr_devel("%s unable to get task %i\n",
64 			 __func__, pid_nr(ctx->pid));
65 		return;
66 	}
67 
68 	if (task->mm != mm)
69 		goto out_put;
70 
71 	pr_devel("%s matched mm - card: %i afu: %i pe: %i\n", __func__,
72 		 ctx->afu->adapter->adapter_num, ctx->afu->slice, ctx->pe);
73 
74 	spin_lock_irqsave(&ctx->sste_lock, flags);
75 	trace_cxl_slbia(ctx);
76 	memset(ctx->sstp, 0, ctx->sst_size);
77 	spin_unlock_irqrestore(&ctx->sste_lock, flags);
78 	mb();
79 	cxl_afu_slbia(ctx->afu);
80 out_put:
81 	put_task_struct(task);
82 }
83 
84 static inline void cxl_slbia_core(struct mm_struct *mm)
85 {
86 	struct cxl *adapter;
87 	struct cxl_afu *afu;
88 	struct cxl_context *ctx;
89 	int card, slice, id;
90 
91 	pr_devel("%s called\n", __func__);
92 
93 	spin_lock(&adapter_idr_lock);
94 	idr_for_each_entry(&cxl_adapter_idr, adapter, card) {
95 		/* XXX: Make this lookup faster with link from mm to ctx */
96 		spin_lock(&adapter->afu_list_lock);
97 		for (slice = 0; slice < adapter->slices; slice++) {
98 			afu = adapter->afu[slice];
99 			if (!afu || !afu->enabled)
100 				continue;
101 			rcu_read_lock();
102 			idr_for_each_entry(&afu->contexts_idr, ctx, id)
103 				_cxl_slbia(ctx, mm);
104 			rcu_read_unlock();
105 		}
106 		spin_unlock(&adapter->afu_list_lock);
107 	}
108 	spin_unlock(&adapter_idr_lock);
109 }
110 
111 static struct cxl_calls cxl_calls = {
112 	.cxl_slbia = cxl_slbia_core,
113 	.cxl_pci_associate_default_context = _cxl_pci_associate_default_context,
114 	.cxl_pci_disable_device = _cxl_pci_disable_device,
115 	.cxl_next_msi_hwirq = _cxl_next_msi_hwirq,
116 	.cxl_cx4_setup_msi_irqs = _cxl_cx4_setup_msi_irqs,
117 	.cxl_cx4_teardown_msi_irqs = _cxl_cx4_teardown_msi_irqs,
118 	.owner = THIS_MODULE,
119 };
120 
121 int cxl_alloc_sst(struct cxl_context *ctx)
122 {
123 	unsigned long vsid;
124 	u64 ea_mask, size, sstp0, sstp1;
125 
126 	sstp0 = 0;
127 	sstp1 = 0;
128 
129 	ctx->sst_size = PAGE_SIZE;
130 	ctx->sst_lru = 0;
131 	ctx->sstp = (struct cxl_sste *)get_zeroed_page(GFP_KERNEL);
132 	if (!ctx->sstp) {
133 		pr_err("cxl_alloc_sst: Unable to allocate segment table\n");
134 		return -ENOMEM;
135 	}
136 	pr_devel("SSTP allocated at 0x%p\n", ctx->sstp);
137 
138 	vsid  = get_kernel_vsid((u64)ctx->sstp, mmu_kernel_ssize) << 12;
139 
140 	sstp0 |= (u64)mmu_kernel_ssize << CXL_SSTP0_An_B_SHIFT;
141 	sstp0 |= (SLB_VSID_KERNEL | mmu_psize_defs[mmu_linear_psize].sllp) << 50;
142 
143 	size = (((u64)ctx->sst_size >> 8) - 1) << CXL_SSTP0_An_SegTableSize_SHIFT;
144 	if (unlikely(size & ~CXL_SSTP0_An_SegTableSize_MASK)) {
145 		WARN(1, "Impossible segment table size\n");
146 		return -EINVAL;
147 	}
148 	sstp0 |= size;
149 
150 	if (mmu_kernel_ssize == MMU_SEGSIZE_256M)
151 		ea_mask = 0xfffff00ULL;
152 	else
153 		ea_mask = 0xffffffff00ULL;
154 
155 	sstp0 |=  vsid >>     (50-14);  /*   Top 14 bits of VSID */
156 	sstp1 |= (vsid << (64-(50-14))) & ~ea_mask;
157 	sstp1 |= (u64)ctx->sstp & ea_mask;
158 	sstp1 |= CXL_SSTP1_An_V;
159 
160 	pr_devel("Looked up %#llx: slbfee. %#llx (ssize: %x, vsid: %#lx), copied to SSTP0: %#llx, SSTP1: %#llx\n",
161 			(u64)ctx->sstp, (u64)ctx->sstp & ESID_MASK, mmu_kernel_ssize, vsid, sstp0, sstp1);
162 
163 	/* Store calculated sstp hardware points for use later */
164 	ctx->sstp0 = sstp0;
165 	ctx->sstp1 = sstp1;
166 
167 	return 0;
168 }
169 
170 /* print buffer content as integers when debugging */
171 void cxl_dump_debug_buffer(void *buf, size_t buf_len)
172 {
173 #ifdef DEBUG
174 	int i, *ptr;
175 
176 	/*
177 	 * We want to regroup up to 4 integers per line, which means they
178 	 * need to be in the same pr_devel() statement
179 	 */
180 	ptr = (int *) buf;
181 	for (i = 0; i * 4 < buf_len; i += 4) {
182 		if ((i + 3) * 4 < buf_len)
183 			pr_devel("%.8x %.8x %.8x %.8x\n", ptr[i], ptr[i + 1],
184 				ptr[i + 2], ptr[i + 3]);
185 		else if ((i + 2) * 4 < buf_len)
186 			pr_devel("%.8x %.8x %.8x\n", ptr[i], ptr[i + 1],
187 				ptr[i + 2]);
188 		else if ((i + 1) * 4 < buf_len)
189 			pr_devel("%.8x %.8x\n", ptr[i], ptr[i + 1]);
190 		else
191 			pr_devel("%.8x\n", ptr[i]);
192 	}
193 #endif /* DEBUG */
194 }
195 
196 /* Find a CXL adapter by it's number and increase it's refcount */
197 struct cxl *get_cxl_adapter(int num)
198 {
199 	struct cxl *adapter;
200 
201 	spin_lock(&adapter_idr_lock);
202 	if ((adapter = idr_find(&cxl_adapter_idr, num)))
203 		get_device(&adapter->dev);
204 	spin_unlock(&adapter_idr_lock);
205 
206 	return adapter;
207 }
208 
209 static int cxl_alloc_adapter_nr(struct cxl *adapter)
210 {
211 	int i;
212 
213 	idr_preload(GFP_KERNEL);
214 	spin_lock(&adapter_idr_lock);
215 	i = idr_alloc(&cxl_adapter_idr, adapter, 0, 0, GFP_NOWAIT);
216 	spin_unlock(&adapter_idr_lock);
217 	idr_preload_end();
218 	if (i < 0)
219 		return i;
220 
221 	adapter->adapter_num = i;
222 
223 	return 0;
224 }
225 
226 void cxl_remove_adapter_nr(struct cxl *adapter)
227 {
228 	idr_remove(&cxl_adapter_idr, adapter->adapter_num);
229 }
230 
231 struct cxl *cxl_alloc_adapter(void)
232 {
233 	struct cxl *adapter;
234 
235 	if (!(adapter = kzalloc(sizeof(struct cxl), GFP_KERNEL)))
236 		return NULL;
237 
238 	spin_lock_init(&adapter->afu_list_lock);
239 
240 	if (cxl_alloc_adapter_nr(adapter))
241 		goto err1;
242 
243 	if (dev_set_name(&adapter->dev, "card%i", adapter->adapter_num))
244 		goto err2;
245 
246 	return adapter;
247 
248 err2:
249 	cxl_remove_adapter_nr(adapter);
250 err1:
251 	kfree(adapter);
252 	return NULL;
253 }
254 
255 struct cxl_afu *cxl_alloc_afu(struct cxl *adapter, int slice)
256 {
257 	struct cxl_afu *afu;
258 
259 	if (!(afu = kzalloc(sizeof(struct cxl_afu), GFP_KERNEL)))
260 		return NULL;
261 
262 	afu->adapter = adapter;
263 	afu->dev.parent = &adapter->dev;
264 	afu->dev.release = cxl_ops->release_afu;
265 	afu->slice = slice;
266 	idr_init(&afu->contexts_idr);
267 	mutex_init(&afu->contexts_lock);
268 	spin_lock_init(&afu->afu_cntl_lock);
269 
270 	afu->prefault_mode = CXL_PREFAULT_NONE;
271 	afu->irqs_max = afu->adapter->user_irqs;
272 
273 	return afu;
274 }
275 
276 int cxl_afu_select_best_mode(struct cxl_afu *afu)
277 {
278 	if (afu->modes_supported & CXL_MODE_DIRECTED)
279 		return cxl_ops->afu_activate_mode(afu, CXL_MODE_DIRECTED);
280 
281 	if (afu->modes_supported & CXL_MODE_DEDICATED)
282 		return cxl_ops->afu_activate_mode(afu, CXL_MODE_DEDICATED);
283 
284 	dev_warn(&afu->dev, "No supported programming modes available\n");
285 	/* We don't fail this so the user can inspect sysfs */
286 	return 0;
287 }
288 
289 static int __init init_cxl(void)
290 {
291 	int rc = 0;
292 
293 	if ((rc = cxl_file_init()))
294 		return rc;
295 
296 	cxl_debugfs_init();
297 
298 	if ((rc = register_cxl_calls(&cxl_calls)))
299 		goto err;
300 
301 	if (cpu_has_feature(CPU_FTR_HVMODE)) {
302 		cxl_ops = &cxl_native_ops;
303 		rc = pci_register_driver(&cxl_pci_driver);
304 	}
305 #ifdef CONFIG_PPC_PSERIES
306 	else {
307 		cxl_ops = &cxl_guest_ops;
308 		rc = platform_driver_register(&cxl_of_driver);
309 	}
310 #endif
311 	if (rc)
312 		goto err1;
313 
314 	return 0;
315 err1:
316 	unregister_cxl_calls(&cxl_calls);
317 err:
318 	cxl_debugfs_exit();
319 	cxl_file_exit();
320 
321 	return rc;
322 }
323 
324 static void exit_cxl(void)
325 {
326 	if (cpu_has_feature(CPU_FTR_HVMODE))
327 		pci_unregister_driver(&cxl_pci_driver);
328 #ifdef CONFIG_PPC_PSERIES
329 	else
330 		platform_driver_unregister(&cxl_of_driver);
331 #endif
332 
333 	cxl_debugfs_exit();
334 	cxl_file_exit();
335 	unregister_cxl_calls(&cxl_calls);
336 	idr_destroy(&cxl_adapter_idr);
337 }
338 
339 module_init(init_cxl);
340 module_exit(exit_cxl);
341 
342 MODULE_DESCRIPTION("IBM Coherent Accelerator");
343 MODULE_AUTHOR("Ian Munsie <imunsie@au1.ibm.com>");
344 MODULE_LICENSE("GPL");
345