xref: /linux/drivers/misc/cxl/main.c (revision 6ea24cf79e055f0a62a64baa8587e2254a493c7b)
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 	.owner = THIS_MODULE,
114 };
115 
116 int cxl_alloc_sst(struct cxl_context *ctx)
117 {
118 	unsigned long vsid;
119 	u64 ea_mask, size, sstp0, sstp1;
120 
121 	sstp0 = 0;
122 	sstp1 = 0;
123 
124 	ctx->sst_size = PAGE_SIZE;
125 	ctx->sst_lru = 0;
126 	ctx->sstp = (struct cxl_sste *)get_zeroed_page(GFP_KERNEL);
127 	if (!ctx->sstp) {
128 		pr_err("cxl_alloc_sst: Unable to allocate segment table\n");
129 		return -ENOMEM;
130 	}
131 	pr_devel("SSTP allocated at 0x%p\n", ctx->sstp);
132 
133 	vsid  = get_kernel_vsid((u64)ctx->sstp, mmu_kernel_ssize) << 12;
134 
135 	sstp0 |= (u64)mmu_kernel_ssize << CXL_SSTP0_An_B_SHIFT;
136 	sstp0 |= (SLB_VSID_KERNEL | mmu_psize_defs[mmu_linear_psize].sllp) << 50;
137 
138 	size = (((u64)ctx->sst_size >> 8) - 1) << CXL_SSTP0_An_SegTableSize_SHIFT;
139 	if (unlikely(size & ~CXL_SSTP0_An_SegTableSize_MASK)) {
140 		WARN(1, "Impossible segment table size\n");
141 		return -EINVAL;
142 	}
143 	sstp0 |= size;
144 
145 	if (mmu_kernel_ssize == MMU_SEGSIZE_256M)
146 		ea_mask = 0xfffff00ULL;
147 	else
148 		ea_mask = 0xffffffff00ULL;
149 
150 	sstp0 |=  vsid >>     (50-14);  /*   Top 14 bits of VSID */
151 	sstp1 |= (vsid << (64-(50-14))) & ~ea_mask;
152 	sstp1 |= (u64)ctx->sstp & ea_mask;
153 	sstp1 |= CXL_SSTP1_An_V;
154 
155 	pr_devel("Looked up %#llx: slbfee. %#llx (ssize: %x, vsid: %#lx), copied to SSTP0: %#llx, SSTP1: %#llx\n",
156 			(u64)ctx->sstp, (u64)ctx->sstp & ESID_MASK, mmu_kernel_ssize, vsid, sstp0, sstp1);
157 
158 	/* Store calculated sstp hardware points for use later */
159 	ctx->sstp0 = sstp0;
160 	ctx->sstp1 = sstp1;
161 
162 	return 0;
163 }
164 
165 /* print buffer content as integers when debugging */
166 void cxl_dump_debug_buffer(void *buf, size_t buf_len)
167 {
168 #ifdef DEBUG
169 	int i, *ptr;
170 
171 	/*
172 	 * We want to regroup up to 4 integers per line, which means they
173 	 * need to be in the same pr_devel() statement
174 	 */
175 	ptr = (int *) buf;
176 	for (i = 0; i * 4 < buf_len; i += 4) {
177 		if ((i + 3) * 4 < buf_len)
178 			pr_devel("%.8x %.8x %.8x %.8x\n", ptr[i], ptr[i + 1],
179 				ptr[i + 2], ptr[i + 3]);
180 		else if ((i + 2) * 4 < buf_len)
181 			pr_devel("%.8x %.8x %.8x\n", ptr[i], ptr[i + 1],
182 				ptr[i + 2]);
183 		else if ((i + 1) * 4 < buf_len)
184 			pr_devel("%.8x %.8x\n", ptr[i], ptr[i + 1]);
185 		else
186 			pr_devel("%.8x\n", ptr[i]);
187 	}
188 #endif /* DEBUG */
189 }
190 
191 /* Find a CXL adapter by it's number and increase it's refcount */
192 struct cxl *get_cxl_adapter(int num)
193 {
194 	struct cxl *adapter;
195 
196 	spin_lock(&adapter_idr_lock);
197 	if ((adapter = idr_find(&cxl_adapter_idr, num)))
198 		get_device(&adapter->dev);
199 	spin_unlock(&adapter_idr_lock);
200 
201 	return adapter;
202 }
203 
204 static int cxl_alloc_adapter_nr(struct cxl *adapter)
205 {
206 	int i;
207 
208 	idr_preload(GFP_KERNEL);
209 	spin_lock(&adapter_idr_lock);
210 	i = idr_alloc(&cxl_adapter_idr, adapter, 0, 0, GFP_NOWAIT);
211 	spin_unlock(&adapter_idr_lock);
212 	idr_preload_end();
213 	if (i < 0)
214 		return i;
215 
216 	adapter->adapter_num = i;
217 
218 	return 0;
219 }
220 
221 void cxl_remove_adapter_nr(struct cxl *adapter)
222 {
223 	idr_remove(&cxl_adapter_idr, adapter->adapter_num);
224 }
225 
226 struct cxl *cxl_alloc_adapter(void)
227 {
228 	struct cxl *adapter;
229 
230 	if (!(adapter = kzalloc(sizeof(struct cxl), GFP_KERNEL)))
231 		return NULL;
232 
233 	spin_lock_init(&adapter->afu_list_lock);
234 
235 	if (cxl_alloc_adapter_nr(adapter))
236 		goto err1;
237 
238 	if (dev_set_name(&adapter->dev, "card%i", adapter->adapter_num))
239 		goto err2;
240 
241 	return adapter;
242 
243 err2:
244 	cxl_remove_adapter_nr(adapter);
245 err1:
246 	kfree(adapter);
247 	return NULL;
248 }
249 
250 struct cxl_afu *cxl_alloc_afu(struct cxl *adapter, int slice)
251 {
252 	struct cxl_afu *afu;
253 
254 	if (!(afu = kzalloc(sizeof(struct cxl_afu), GFP_KERNEL)))
255 		return NULL;
256 
257 	afu->adapter = adapter;
258 	afu->dev.parent = &adapter->dev;
259 	afu->dev.release = cxl_ops->release_afu;
260 	afu->slice = slice;
261 	idr_init(&afu->contexts_idr);
262 	mutex_init(&afu->contexts_lock);
263 	spin_lock_init(&afu->afu_cntl_lock);
264 
265 	afu->prefault_mode = CXL_PREFAULT_NONE;
266 	afu->irqs_max = afu->adapter->user_irqs;
267 
268 	return afu;
269 }
270 
271 int cxl_afu_select_best_mode(struct cxl_afu *afu)
272 {
273 	if (afu->modes_supported & CXL_MODE_DIRECTED)
274 		return cxl_ops->afu_activate_mode(afu, CXL_MODE_DIRECTED);
275 
276 	if (afu->modes_supported & CXL_MODE_DEDICATED)
277 		return cxl_ops->afu_activate_mode(afu, CXL_MODE_DEDICATED);
278 
279 	dev_warn(&afu->dev, "No supported programming modes available\n");
280 	/* We don't fail this so the user can inspect sysfs */
281 	return 0;
282 }
283 
284 static int __init init_cxl(void)
285 {
286 	int rc = 0;
287 
288 	if ((rc = cxl_file_init()))
289 		return rc;
290 
291 	cxl_debugfs_init();
292 
293 	if ((rc = register_cxl_calls(&cxl_calls)))
294 		goto err;
295 
296 	if (cpu_has_feature(CPU_FTR_HVMODE)) {
297 		cxl_ops = &cxl_native_ops;
298 		rc = pci_register_driver(&cxl_pci_driver);
299 	}
300 #ifdef CONFIG_PPC_PSERIES
301 	else {
302 		cxl_ops = &cxl_guest_ops;
303 		rc = platform_driver_register(&cxl_of_driver);
304 	}
305 #endif
306 	if (rc)
307 		goto err1;
308 
309 	return 0;
310 err1:
311 	unregister_cxl_calls(&cxl_calls);
312 err:
313 	cxl_debugfs_exit();
314 	cxl_file_exit();
315 
316 	return rc;
317 }
318 
319 static void exit_cxl(void)
320 {
321 	if (cpu_has_feature(CPU_FTR_HVMODE))
322 		pci_unregister_driver(&cxl_pci_driver);
323 #ifdef CONFIG_PPC_PSERIES
324 	else
325 		platform_driver_unregister(&cxl_of_driver);
326 #endif
327 
328 	cxl_debugfs_exit();
329 	cxl_file_exit();
330 	unregister_cxl_calls(&cxl_calls);
331 	idr_destroy(&cxl_adapter_idr);
332 }
333 
334 module_init(init_cxl);
335 module_exit(exit_cxl);
336 
337 MODULE_DESCRIPTION("IBM Coherent Accelerator");
338 MODULE_AUTHOR("Ian Munsie <imunsie@au1.ibm.com>");
339 MODULE_LICENSE("GPL");
340