xref: /linux/drivers/misc/cxl/main.c (revision d56d301b51746e71f7bdaaba10973f054c3c736e)
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 int cxl_afu_slbia(struct cxl_afu *afu)
36 {
37 	unsigned long timeout = jiffies + (HZ * CXL_TIMEOUT);
38 
39 	pr_devel("cxl_afu_slbia issuing SLBIA command\n");
40 	cxl_p2n_write(afu, CXL_SLBIA_An, CXL_TLB_SLB_IQ_ALL);
41 	while (cxl_p2n_read(afu, CXL_SLBIA_An) & CXL_TLB_SLB_P) {
42 		if (time_after_eq(jiffies, timeout)) {
43 			dev_warn(&afu->dev, "WARNING: CXL AFU SLBIA timed out!\n");
44 			return -EBUSY;
45 		}
46 		/* If the adapter has gone down, we can assume that we
47 		 * will PERST it and that will invalidate everything.
48 		 */
49 		if (!cxl_adapter_link_ok(afu->adapter))
50 			return -EIO;
51 		cpu_relax();
52 	}
53 	return 0;
54 }
55 
56 static inline void _cxl_slbia(struct cxl_context *ctx, struct mm_struct *mm)
57 {
58 	struct task_struct *task;
59 	unsigned long flags;
60 	if (!(task = get_pid_task(ctx->pid, PIDTYPE_PID))) {
61 		pr_devel("%s unable to get task %i\n",
62 			 __func__, pid_nr(ctx->pid));
63 		return;
64 	}
65 
66 	if (task->mm != mm)
67 		goto out_put;
68 
69 	pr_devel("%s matched mm - card: %i afu: %i pe: %i\n", __func__,
70 		 ctx->afu->adapter->adapter_num, ctx->afu->slice, ctx->pe);
71 
72 	spin_lock_irqsave(&ctx->sste_lock, flags);
73 	trace_cxl_slbia(ctx);
74 	memset(ctx->sstp, 0, ctx->sst_size);
75 	spin_unlock_irqrestore(&ctx->sste_lock, flags);
76 	mb();
77 	cxl_afu_slbia(ctx->afu);
78 out_put:
79 	put_task_struct(task);
80 }
81 
82 static inline void cxl_slbia_core(struct mm_struct *mm)
83 {
84 	struct cxl *adapter;
85 	struct cxl_afu *afu;
86 	struct cxl_context *ctx;
87 	int card, slice, id;
88 
89 	pr_devel("%s called\n", __func__);
90 
91 	spin_lock(&adapter_idr_lock);
92 	idr_for_each_entry(&cxl_adapter_idr, adapter, card) {
93 		/* XXX: Make this lookup faster with link from mm to ctx */
94 		spin_lock(&adapter->afu_list_lock);
95 		for (slice = 0; slice < adapter->slices; slice++) {
96 			afu = adapter->afu[slice];
97 			if (!afu || !afu->enabled)
98 				continue;
99 			rcu_read_lock();
100 			idr_for_each_entry(&afu->contexts_idr, ctx, id)
101 				_cxl_slbia(ctx, mm);
102 			rcu_read_unlock();
103 		}
104 		spin_unlock(&adapter->afu_list_lock);
105 	}
106 	spin_unlock(&adapter_idr_lock);
107 }
108 
109 static struct cxl_calls cxl_calls = {
110 	.cxl_slbia = cxl_slbia_core,
111 	.owner = THIS_MODULE,
112 };
113 
114 int cxl_alloc_sst(struct cxl_context *ctx)
115 {
116 	unsigned long vsid;
117 	u64 ea_mask, size, sstp0, sstp1;
118 
119 	sstp0 = 0;
120 	sstp1 = 0;
121 
122 	ctx->sst_size = PAGE_SIZE;
123 	ctx->sst_lru = 0;
124 	ctx->sstp = (struct cxl_sste *)get_zeroed_page(GFP_KERNEL);
125 	if (!ctx->sstp) {
126 		pr_err("cxl_alloc_sst: Unable to allocate segment table\n");
127 		return -ENOMEM;
128 	}
129 	pr_devel("SSTP allocated at 0x%p\n", ctx->sstp);
130 
131 	vsid  = get_kernel_vsid((u64)ctx->sstp, mmu_kernel_ssize) << 12;
132 
133 	sstp0 |= (u64)mmu_kernel_ssize << CXL_SSTP0_An_B_SHIFT;
134 	sstp0 |= (SLB_VSID_KERNEL | mmu_psize_defs[mmu_linear_psize].sllp) << 50;
135 
136 	size = (((u64)ctx->sst_size >> 8) - 1) << CXL_SSTP0_An_SegTableSize_SHIFT;
137 	if (unlikely(size & ~CXL_SSTP0_An_SegTableSize_MASK)) {
138 		WARN(1, "Impossible segment table size\n");
139 		return -EINVAL;
140 	}
141 	sstp0 |= size;
142 
143 	if (mmu_kernel_ssize == MMU_SEGSIZE_256M)
144 		ea_mask = 0xfffff00ULL;
145 	else
146 		ea_mask = 0xffffffff00ULL;
147 
148 	sstp0 |=  vsid >>     (50-14);  /*   Top 14 bits of VSID */
149 	sstp1 |= (vsid << (64-(50-14))) & ~ea_mask;
150 	sstp1 |= (u64)ctx->sstp & ea_mask;
151 	sstp1 |= CXL_SSTP1_An_V;
152 
153 	pr_devel("Looked up %#llx: slbfee. %#llx (ssize: %x, vsid: %#lx), copied to SSTP0: %#llx, SSTP1: %#llx\n",
154 			(u64)ctx->sstp, (u64)ctx->sstp & ESID_MASK, mmu_kernel_ssize, vsid, sstp0, sstp1);
155 
156 	/* Store calculated sstp hardware points for use later */
157 	ctx->sstp0 = sstp0;
158 	ctx->sstp1 = sstp1;
159 
160 	return 0;
161 }
162 
163 /* Find a CXL adapter by it's number and increase it's refcount */
164 struct cxl *get_cxl_adapter(int num)
165 {
166 	struct cxl *adapter;
167 
168 	spin_lock(&adapter_idr_lock);
169 	if ((adapter = idr_find(&cxl_adapter_idr, num)))
170 		get_device(&adapter->dev);
171 	spin_unlock(&adapter_idr_lock);
172 
173 	return adapter;
174 }
175 
176 static int cxl_alloc_adapter_nr(struct cxl *adapter)
177 {
178 	int i;
179 
180 	idr_preload(GFP_KERNEL);
181 	spin_lock(&adapter_idr_lock);
182 	i = idr_alloc(&cxl_adapter_idr, adapter, 0, 0, GFP_NOWAIT);
183 	spin_unlock(&adapter_idr_lock);
184 	idr_preload_end();
185 	if (i < 0)
186 		return i;
187 
188 	adapter->adapter_num = i;
189 
190 	return 0;
191 }
192 
193 void cxl_remove_adapter_nr(struct cxl *adapter)
194 {
195 	idr_remove(&cxl_adapter_idr, adapter->adapter_num);
196 }
197 
198 struct cxl *cxl_alloc_adapter(void)
199 {
200 	struct cxl *adapter;
201 
202 	if (!(adapter = kzalloc(sizeof(struct cxl), GFP_KERNEL)))
203 		return NULL;
204 
205 	spin_lock_init(&adapter->afu_list_lock);
206 
207 	if (cxl_alloc_adapter_nr(adapter))
208 		goto err1;
209 
210 	if (dev_set_name(&adapter->dev, "card%i", adapter->adapter_num))
211 		goto err2;
212 
213 	return adapter;
214 
215 err2:
216 	cxl_remove_adapter_nr(adapter);
217 err1:
218 	kfree(adapter);
219 	return NULL;
220 }
221 
222 struct cxl_afu *cxl_alloc_afu(struct cxl *adapter, int slice)
223 {
224 	struct cxl_afu *afu;
225 
226 	if (!(afu = kzalloc(sizeof(struct cxl_afu), GFP_KERNEL)))
227 		return NULL;
228 
229 	afu->adapter = adapter;
230 	afu->dev.parent = &adapter->dev;
231 	afu->dev.release = cxl_release_afu;
232 	afu->slice = slice;
233 	idr_init(&afu->contexts_idr);
234 	mutex_init(&afu->contexts_lock);
235 	spin_lock_init(&afu->afu_cntl_lock);
236 	mutex_init(&afu->spa_mutex);
237 
238 	afu->prefault_mode = CXL_PREFAULT_NONE;
239 	afu->irqs_max = afu->adapter->user_irqs;
240 
241 	return afu;
242 }
243 
244 int cxl_afu_select_best_mode(struct cxl_afu *afu)
245 {
246 	if (afu->modes_supported & CXL_MODE_DIRECTED)
247 		return cxl_afu_activate_mode(afu, CXL_MODE_DIRECTED);
248 
249 	if (afu->modes_supported & CXL_MODE_DEDICATED)
250 		return cxl_afu_activate_mode(afu, CXL_MODE_DEDICATED);
251 
252 	dev_warn(&afu->dev, "No supported programming modes available\n");
253 	/* We don't fail this so the user can inspect sysfs */
254 	return 0;
255 }
256 
257 static int __init init_cxl(void)
258 {
259 	int rc = 0;
260 
261 	if (!cpu_has_feature(CPU_FTR_HVMODE))
262 		return -EPERM;
263 
264 	if ((rc = cxl_file_init()))
265 		return rc;
266 
267 	cxl_debugfs_init();
268 
269 	if ((rc = register_cxl_calls(&cxl_calls)))
270 		goto err;
271 
272 	if ((rc = pci_register_driver(&cxl_pci_driver)))
273 		goto err1;
274 
275 	return 0;
276 err1:
277 	unregister_cxl_calls(&cxl_calls);
278 err:
279 	cxl_debugfs_exit();
280 	cxl_file_exit();
281 
282 	return rc;
283 }
284 
285 static void exit_cxl(void)
286 {
287 	pci_unregister_driver(&cxl_pci_driver);
288 
289 	cxl_debugfs_exit();
290 	cxl_file_exit();
291 	unregister_cxl_calls(&cxl_calls);
292 	idr_destroy(&cxl_adapter_idr);
293 }
294 
295 module_init(init_cxl);
296 module_exit(exit_cxl);
297 
298 MODULE_DESCRIPTION("IBM Coherent Accelerator");
299 MODULE_AUTHOR("Ian Munsie <imunsie@au1.ibm.com>");
300 MODULE_LICENSE("GPL");
301