1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * Copyright 2014 IBM Corp.
4 */
5
6 #include <linux/spinlock.h>
7 #include <linux/kernel.h>
8 #include <linux/module.h>
9 #include <linux/device.h>
10 #include <linux/mutex.h>
11 #include <linux/init.h>
12 #include <linux/list.h>
13 #include <linux/mm.h>
14 #include <linux/of.h>
15 #include <linux/slab.h>
16 #include <linux/idr.h>
17 #include <linux/pci.h>
18 #include <linux/platform_device.h>
19 #include <linux/sched/task.h>
20
21 #include <asm/cputable.h>
22 #include <asm/mmu.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
cxl_afu_slbia(struct cxl_afu * afu)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
_cxl_slbia(struct cxl_context * ctx,struct mm_struct * mm)58 static inline void _cxl_slbia(struct cxl_context *ctx, struct mm_struct *mm)
59 {
60 unsigned long flags;
61
62 if (ctx->mm != mm)
63 return;
64
65 pr_devel("%s matched mm - card: %i afu: %i pe: %i\n", __func__,
66 ctx->afu->adapter->adapter_num, ctx->afu->slice, ctx->pe);
67
68 spin_lock_irqsave(&ctx->sste_lock, flags);
69 trace_cxl_slbia(ctx);
70 memset(ctx->sstp, 0, ctx->sst_size);
71 spin_unlock_irqrestore(&ctx->sste_lock, flags);
72 mb();
73 cxl_afu_slbia(ctx->afu);
74 }
75
cxl_slbia_core(struct mm_struct * mm)76 static inline void cxl_slbia_core(struct mm_struct *mm)
77 {
78 struct cxl *adapter;
79 struct cxl_afu *afu;
80 struct cxl_context *ctx;
81 int card, slice, id;
82
83 pr_devel("%s called\n", __func__);
84
85 spin_lock(&adapter_idr_lock);
86 idr_for_each_entry(&cxl_adapter_idr, adapter, card) {
87 /* XXX: Make this lookup faster with link from mm to ctx */
88 spin_lock(&adapter->afu_list_lock);
89 for (slice = 0; slice < adapter->slices; slice++) {
90 afu = adapter->afu[slice];
91 if (!afu || !afu->enabled)
92 continue;
93 rcu_read_lock();
94 idr_for_each_entry(&afu->contexts_idr, ctx, id)
95 _cxl_slbia(ctx, mm);
96 rcu_read_unlock();
97 }
98 spin_unlock(&adapter->afu_list_lock);
99 }
100 spin_unlock(&adapter_idr_lock);
101 }
102
103 static struct cxl_calls cxl_calls = {
104 .cxl_slbia = cxl_slbia_core,
105 .owner = THIS_MODULE,
106 };
107
cxl_alloc_sst(struct cxl_context * ctx)108 int cxl_alloc_sst(struct cxl_context *ctx)
109 {
110 unsigned long vsid;
111 u64 ea_mask, size, sstp0, sstp1;
112
113 sstp0 = 0;
114 sstp1 = 0;
115
116 ctx->sst_size = PAGE_SIZE;
117 ctx->sst_lru = 0;
118 ctx->sstp = (struct cxl_sste *)get_zeroed_page(GFP_KERNEL);
119 if (!ctx->sstp) {
120 pr_err("cxl_alloc_sst: Unable to allocate segment table\n");
121 return -ENOMEM;
122 }
123 pr_devel("SSTP allocated at 0x%p\n", ctx->sstp);
124
125 vsid = get_kernel_vsid((u64)ctx->sstp, mmu_kernel_ssize) << 12;
126
127 sstp0 |= (u64)mmu_kernel_ssize << CXL_SSTP0_An_B_SHIFT;
128 sstp0 |= (SLB_VSID_KERNEL | mmu_psize_defs[mmu_linear_psize].sllp) << 50;
129
130 size = (((u64)ctx->sst_size >> 8) - 1) << CXL_SSTP0_An_SegTableSize_SHIFT;
131 if (unlikely(size & ~CXL_SSTP0_An_SegTableSize_MASK)) {
132 WARN(1, "Impossible segment table size\n");
133 return -EINVAL;
134 }
135 sstp0 |= size;
136
137 if (mmu_kernel_ssize == MMU_SEGSIZE_256M)
138 ea_mask = 0xfffff00ULL;
139 else
140 ea_mask = 0xffffffff00ULL;
141
142 sstp0 |= vsid >> (50-14); /* Top 14 bits of VSID */
143 sstp1 |= (vsid << (64-(50-14))) & ~ea_mask;
144 sstp1 |= (u64)ctx->sstp & ea_mask;
145 sstp1 |= CXL_SSTP1_An_V;
146
147 pr_devel("Looked up %#llx: slbfee. %#llx (ssize: %x, vsid: %#lx), copied to SSTP0: %#llx, SSTP1: %#llx\n",
148 (u64)ctx->sstp, (u64)ctx->sstp & ESID_MASK, mmu_kernel_ssize, vsid, sstp0, sstp1);
149
150 /* Store calculated sstp hardware points for use later */
151 ctx->sstp0 = sstp0;
152 ctx->sstp1 = sstp1;
153
154 return 0;
155 }
156
157 /* print buffer content as integers when debugging */
cxl_dump_debug_buffer(void * buf,size_t buf_len)158 void cxl_dump_debug_buffer(void *buf, size_t buf_len)
159 {
160 #ifdef DEBUG
161 int i, *ptr;
162
163 /*
164 * We want to regroup up to 4 integers per line, which means they
165 * need to be in the same pr_devel() statement
166 */
167 ptr = (int *) buf;
168 for (i = 0; i * 4 < buf_len; i += 4) {
169 if ((i + 3) * 4 < buf_len)
170 pr_devel("%.8x %.8x %.8x %.8x\n", ptr[i], ptr[i + 1],
171 ptr[i + 2], ptr[i + 3]);
172 else if ((i + 2) * 4 < buf_len)
173 pr_devel("%.8x %.8x %.8x\n", ptr[i], ptr[i + 1],
174 ptr[i + 2]);
175 else if ((i + 1) * 4 < buf_len)
176 pr_devel("%.8x %.8x\n", ptr[i], ptr[i + 1]);
177 else
178 pr_devel("%.8x\n", ptr[i]);
179 }
180 #endif /* DEBUG */
181 }
182
183 /* Find a CXL adapter by it's number and increase it's refcount */
get_cxl_adapter(int num)184 struct cxl *get_cxl_adapter(int num)
185 {
186 struct cxl *adapter;
187
188 spin_lock(&adapter_idr_lock);
189 if ((adapter = idr_find(&cxl_adapter_idr, num)))
190 get_device(&adapter->dev);
191 spin_unlock(&adapter_idr_lock);
192
193 return adapter;
194 }
195
cxl_alloc_adapter_nr(struct cxl * adapter)196 static int cxl_alloc_adapter_nr(struct cxl *adapter)
197 {
198 int i;
199
200 idr_preload(GFP_KERNEL);
201 spin_lock(&adapter_idr_lock);
202 i = idr_alloc(&cxl_adapter_idr, adapter, 0, 0, GFP_NOWAIT);
203 spin_unlock(&adapter_idr_lock);
204 idr_preload_end();
205 if (i < 0)
206 return i;
207
208 adapter->adapter_num = i;
209
210 return 0;
211 }
212
cxl_remove_adapter_nr(struct cxl * adapter)213 void cxl_remove_adapter_nr(struct cxl *adapter)
214 {
215 idr_remove(&cxl_adapter_idr, adapter->adapter_num);
216 }
217
cxl_alloc_adapter(void)218 struct cxl *cxl_alloc_adapter(void)
219 {
220 struct cxl *adapter;
221
222 if (!(adapter = kzalloc(sizeof(struct cxl), GFP_KERNEL)))
223 return NULL;
224
225 spin_lock_init(&adapter->afu_list_lock);
226
227 if (cxl_alloc_adapter_nr(adapter))
228 goto err1;
229
230 if (dev_set_name(&adapter->dev, "card%i", adapter->adapter_num))
231 goto err2;
232
233 /* start with context lock taken */
234 atomic_set(&adapter->contexts_num, -1);
235
236 return adapter;
237 err2:
238 cxl_remove_adapter_nr(adapter);
239 err1:
240 kfree(adapter);
241 return NULL;
242 }
243
cxl_alloc_afu(struct cxl * adapter,int slice)244 struct cxl_afu *cxl_alloc_afu(struct cxl *adapter, int slice)
245 {
246 struct cxl_afu *afu;
247
248 if (!(afu = kzalloc(sizeof(struct cxl_afu), GFP_KERNEL)))
249 return NULL;
250
251 afu->adapter = adapter;
252 afu->dev.parent = &adapter->dev;
253 afu->dev.release = cxl_ops->release_afu;
254 afu->slice = slice;
255 idr_init(&afu->contexts_idr);
256 mutex_init(&afu->contexts_lock);
257 spin_lock_init(&afu->afu_cntl_lock);
258 atomic_set(&afu->configured_state, -1);
259 afu->prefault_mode = CXL_PREFAULT_NONE;
260 afu->irqs_max = afu->adapter->user_irqs;
261
262 return afu;
263 }
264
cxl_afu_select_best_mode(struct cxl_afu * afu)265 int cxl_afu_select_best_mode(struct cxl_afu *afu)
266 {
267 if (afu->modes_supported & CXL_MODE_DIRECTED)
268 return cxl_ops->afu_activate_mode(afu, CXL_MODE_DIRECTED);
269
270 if (afu->modes_supported & CXL_MODE_DEDICATED)
271 return cxl_ops->afu_activate_mode(afu, CXL_MODE_DEDICATED);
272
273 dev_warn(&afu->dev, "No supported programming modes available\n");
274 /* We don't fail this so the user can inspect sysfs */
275 return 0;
276 }
277
cxl_adapter_context_get(struct cxl * adapter)278 int cxl_adapter_context_get(struct cxl *adapter)
279 {
280 int rc;
281
282 rc = atomic_inc_unless_negative(&adapter->contexts_num);
283 return rc ? 0 : -EBUSY;
284 }
285
cxl_adapter_context_put(struct cxl * adapter)286 void cxl_adapter_context_put(struct cxl *adapter)
287 {
288 atomic_dec_if_positive(&adapter->contexts_num);
289 }
290
cxl_adapter_context_lock(struct cxl * adapter)291 int cxl_adapter_context_lock(struct cxl *adapter)
292 {
293 int rc;
294 /* no active contexts -> contexts_num == 0 */
295 rc = atomic_cmpxchg(&adapter->contexts_num, 0, -1);
296 return rc ? -EBUSY : 0;
297 }
298
cxl_adapter_context_unlock(struct cxl * adapter)299 void cxl_adapter_context_unlock(struct cxl *adapter)
300 {
301 int val = atomic_cmpxchg(&adapter->contexts_num, -1, 0);
302
303 /*
304 * contexts lock taken -> contexts_num == -1
305 * If not true then show a warning and force reset the lock.
306 * This will happen when context_unlock was requested without
307 * doing a context_lock.
308 */
309 if (val != -1) {
310 atomic_set(&adapter->contexts_num, 0);
311 WARN(1, "Adapter context unlocked with %d active contexts",
312 val);
313 }
314 }
315
init_cxl(void)316 static int __init init_cxl(void)
317 {
318 int rc = 0;
319
320 if (!tlbie_capable)
321 return -EINVAL;
322
323 if ((rc = cxl_file_init()))
324 return rc;
325
326 cxl_debugfs_init();
327
328 /*
329 * we don't register the callback on P9. slb callack is only
330 * used for the PSL8 MMU and CX4.
331 */
332 if (cxl_is_power8()) {
333 rc = register_cxl_calls(&cxl_calls);
334 if (rc)
335 goto err;
336 }
337
338 if (cpu_has_feature(CPU_FTR_HVMODE)) {
339 cxl_ops = &cxl_native_ops;
340 rc = pci_register_driver(&cxl_pci_driver);
341 }
342 #ifdef CONFIG_PPC_PSERIES
343 else {
344 cxl_ops = &cxl_guest_ops;
345 rc = platform_driver_register(&cxl_of_driver);
346 }
347 #endif
348 if (rc)
349 goto err1;
350
351 return 0;
352 err1:
353 if (cxl_is_power8())
354 unregister_cxl_calls(&cxl_calls);
355 err:
356 cxl_debugfs_exit();
357 cxl_file_exit();
358
359 return rc;
360 }
361
exit_cxl(void)362 static void exit_cxl(void)
363 {
364 if (cpu_has_feature(CPU_FTR_HVMODE))
365 pci_unregister_driver(&cxl_pci_driver);
366 #ifdef CONFIG_PPC_PSERIES
367 else
368 platform_driver_unregister(&cxl_of_driver);
369 #endif
370
371 cxl_debugfs_exit();
372 cxl_file_exit();
373 if (cxl_is_power8())
374 unregister_cxl_calls(&cxl_calls);
375 idr_destroy(&cxl_adapter_idr);
376 }
377
378 module_init(init_cxl);
379 module_exit(exit_cxl);
380
381 MODULE_DESCRIPTION("IBM Coherent Accelerator");
382 MODULE_AUTHOR("Ian Munsie <imunsie@au1.ibm.com>");
383 MODULE_LICENSE("GPL");
384