Loading...
Note: File does not exist in v3.1.
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 <linux/sched/task.h>
23
24#include <asm/cputable.h>
25#include <misc/cxl-base.h>
26
27#include "cxl.h"
28#include "trace.h"
29
30static DEFINE_SPINLOCK(adapter_idr_lock);
31static DEFINE_IDR(cxl_adapter_idr);
32
33uint cxl_verbose;
34module_param_named(verbose, cxl_verbose, uint, 0600);
35MODULE_PARM_DESC(verbose, "Enable verbose dmesg output");
36
37const struct cxl_backend_ops *cxl_ops;
38
39int cxl_afu_slbia(struct cxl_afu *afu)
40{
41 unsigned long timeout = jiffies + (HZ * CXL_TIMEOUT);
42
43 pr_devel("cxl_afu_slbia issuing SLBIA command\n");
44 cxl_p2n_write(afu, CXL_SLBIA_An, CXL_TLB_SLB_IQ_ALL);
45 while (cxl_p2n_read(afu, CXL_SLBIA_An) & CXL_TLB_SLB_P) {
46 if (time_after_eq(jiffies, timeout)) {
47 dev_warn(&afu->dev, "WARNING: CXL AFU SLBIA timed out!\n");
48 return -EBUSY;
49 }
50 /* If the adapter has gone down, we can assume that we
51 * will PERST it and that will invalidate everything.
52 */
53 if (!cxl_ops->link_ok(afu->adapter, afu))
54 return -EIO;
55 cpu_relax();
56 }
57 return 0;
58}
59
60static inline void _cxl_slbia(struct cxl_context *ctx, struct mm_struct *mm)
61{
62 unsigned long flags;
63
64 if (ctx->mm != mm)
65 return;
66
67 pr_devel("%s matched mm - card: %i afu: %i pe: %i\n", __func__,
68 ctx->afu->adapter->adapter_num, ctx->afu->slice, ctx->pe);
69
70 spin_lock_irqsave(&ctx->sste_lock, flags);
71 trace_cxl_slbia(ctx);
72 memset(ctx->sstp, 0, ctx->sst_size);
73 spin_unlock_irqrestore(&ctx->sste_lock, flags);
74 mb();
75 cxl_afu_slbia(ctx->afu);
76}
77
78static inline void cxl_slbia_core(struct mm_struct *mm)
79{
80 struct cxl *adapter;
81 struct cxl_afu *afu;
82 struct cxl_context *ctx;
83 int card, slice, id;
84
85 pr_devel("%s called\n", __func__);
86
87 spin_lock(&adapter_idr_lock);
88 idr_for_each_entry(&cxl_adapter_idr, adapter, card) {
89 /* XXX: Make this lookup faster with link from mm to ctx */
90 spin_lock(&adapter->afu_list_lock);
91 for (slice = 0; slice < adapter->slices; slice++) {
92 afu = adapter->afu[slice];
93 if (!afu || !afu->enabled)
94 continue;
95 rcu_read_lock();
96 idr_for_each_entry(&afu->contexts_idr, ctx, id)
97 _cxl_slbia(ctx, mm);
98 rcu_read_unlock();
99 }
100 spin_unlock(&adapter->afu_list_lock);
101 }
102 spin_unlock(&adapter_idr_lock);
103}
104
105static struct cxl_calls cxl_calls = {
106 .cxl_slbia = cxl_slbia_core,
107 .cxl_pci_associate_default_context = _cxl_pci_associate_default_context,
108 .cxl_pci_disable_device = _cxl_pci_disable_device,
109 .cxl_next_msi_hwirq = _cxl_next_msi_hwirq,
110 .cxl_cx4_setup_msi_irqs = _cxl_cx4_setup_msi_irqs,
111 .cxl_cx4_teardown_msi_irqs = _cxl_cx4_teardown_msi_irqs,
112 .owner = THIS_MODULE,
113};
114
115int cxl_alloc_sst(struct cxl_context *ctx)
116{
117 unsigned long vsid;
118 u64 ea_mask, size, sstp0, sstp1;
119
120 sstp0 = 0;
121 sstp1 = 0;
122
123 ctx->sst_size = PAGE_SIZE;
124 ctx->sst_lru = 0;
125 ctx->sstp = (struct cxl_sste *)get_zeroed_page(GFP_KERNEL);
126 if (!ctx->sstp) {
127 pr_err("cxl_alloc_sst: Unable to allocate segment table\n");
128 return -ENOMEM;
129 }
130 pr_devel("SSTP allocated at 0x%p\n", ctx->sstp);
131
132 vsid = get_kernel_vsid((u64)ctx->sstp, mmu_kernel_ssize) << 12;
133
134 sstp0 |= (u64)mmu_kernel_ssize << CXL_SSTP0_An_B_SHIFT;
135 sstp0 |= (SLB_VSID_KERNEL | mmu_psize_defs[mmu_linear_psize].sllp) << 50;
136
137 size = (((u64)ctx->sst_size >> 8) - 1) << CXL_SSTP0_An_SegTableSize_SHIFT;
138 if (unlikely(size & ~CXL_SSTP0_An_SegTableSize_MASK)) {
139 WARN(1, "Impossible segment table size\n");
140 return -EINVAL;
141 }
142 sstp0 |= size;
143
144 if (mmu_kernel_ssize == MMU_SEGSIZE_256M)
145 ea_mask = 0xfffff00ULL;
146 else
147 ea_mask = 0xffffffff00ULL;
148
149 sstp0 |= vsid >> (50-14); /* Top 14 bits of VSID */
150 sstp1 |= (vsid << (64-(50-14))) & ~ea_mask;
151 sstp1 |= (u64)ctx->sstp & ea_mask;
152 sstp1 |= CXL_SSTP1_An_V;
153
154 pr_devel("Looked up %#llx: slbfee. %#llx (ssize: %x, vsid: %#lx), copied to SSTP0: %#llx, SSTP1: %#llx\n",
155 (u64)ctx->sstp, (u64)ctx->sstp & ESID_MASK, mmu_kernel_ssize, vsid, sstp0, sstp1);
156
157 /* Store calculated sstp hardware points for use later */
158 ctx->sstp0 = sstp0;
159 ctx->sstp1 = sstp1;
160
161 return 0;
162}
163
164/* print buffer content as integers when debugging */
165void cxl_dump_debug_buffer(void *buf, size_t buf_len)
166{
167#ifdef DEBUG
168 int i, *ptr;
169
170 /*
171 * We want to regroup up to 4 integers per line, which means they
172 * need to be in the same pr_devel() statement
173 */
174 ptr = (int *) buf;
175 for (i = 0; i * 4 < buf_len; i += 4) {
176 if ((i + 3) * 4 < buf_len)
177 pr_devel("%.8x %.8x %.8x %.8x\n", ptr[i], ptr[i + 1],
178 ptr[i + 2], ptr[i + 3]);
179 else if ((i + 2) * 4 < buf_len)
180 pr_devel("%.8x %.8x %.8x\n", ptr[i], ptr[i + 1],
181 ptr[i + 2]);
182 else if ((i + 1) * 4 < buf_len)
183 pr_devel("%.8x %.8x\n", ptr[i], ptr[i + 1]);
184 else
185 pr_devel("%.8x\n", ptr[i]);
186 }
187#endif /* DEBUG */
188}
189
190/* Find a CXL adapter by it's number and increase it's refcount */
191struct cxl *get_cxl_adapter(int num)
192{
193 struct cxl *adapter;
194
195 spin_lock(&adapter_idr_lock);
196 if ((adapter = idr_find(&cxl_adapter_idr, num)))
197 get_device(&adapter->dev);
198 spin_unlock(&adapter_idr_lock);
199
200 return adapter;
201}
202
203static int cxl_alloc_adapter_nr(struct cxl *adapter)
204{
205 int i;
206
207 idr_preload(GFP_KERNEL);
208 spin_lock(&adapter_idr_lock);
209 i = idr_alloc(&cxl_adapter_idr, adapter, 0, 0, GFP_NOWAIT);
210 spin_unlock(&adapter_idr_lock);
211 idr_preload_end();
212 if (i < 0)
213 return i;
214
215 adapter->adapter_num = i;
216
217 return 0;
218}
219
220void cxl_remove_adapter_nr(struct cxl *adapter)
221{
222 idr_remove(&cxl_adapter_idr, adapter->adapter_num);
223}
224
225struct cxl *cxl_alloc_adapter(void)
226{
227 struct cxl *adapter;
228
229 if (!(adapter = kzalloc(sizeof(struct cxl), GFP_KERNEL)))
230 return NULL;
231
232 spin_lock_init(&adapter->afu_list_lock);
233
234 if (cxl_alloc_adapter_nr(adapter))
235 goto err1;
236
237 if (dev_set_name(&adapter->dev, "card%i", adapter->adapter_num))
238 goto err2;
239
240 /* start with context lock taken */
241 atomic_set(&adapter->contexts_num, -1);
242
243 return adapter;
244err2:
245 cxl_remove_adapter_nr(adapter);
246err1:
247 kfree(adapter);
248 return NULL;
249}
250
251struct cxl_afu *cxl_alloc_afu(struct cxl *adapter, int slice)
252{
253 struct cxl_afu *afu;
254
255 if (!(afu = kzalloc(sizeof(struct cxl_afu), GFP_KERNEL)))
256 return NULL;
257
258 afu->adapter = adapter;
259 afu->dev.parent = &adapter->dev;
260 afu->dev.release = cxl_ops->release_afu;
261 afu->slice = slice;
262 idr_init(&afu->contexts_idr);
263 mutex_init(&afu->contexts_lock);
264 spin_lock_init(&afu->afu_cntl_lock);
265 atomic_set(&afu->configured_state, -1);
266 afu->prefault_mode = CXL_PREFAULT_NONE;
267 afu->irqs_max = afu->adapter->user_irqs;
268
269 return afu;
270}
271
272int cxl_afu_select_best_mode(struct cxl_afu *afu)
273{
274 if (afu->modes_supported & CXL_MODE_DIRECTED)
275 return cxl_ops->afu_activate_mode(afu, CXL_MODE_DIRECTED);
276
277 if (afu->modes_supported & CXL_MODE_DEDICATED)
278 return cxl_ops->afu_activate_mode(afu, CXL_MODE_DEDICATED);
279
280 dev_warn(&afu->dev, "No supported programming modes available\n");
281 /* We don't fail this so the user can inspect sysfs */
282 return 0;
283}
284
285int cxl_adapter_context_get(struct cxl *adapter)
286{
287 int rc;
288
289 rc = atomic_inc_unless_negative(&adapter->contexts_num);
290 return rc >= 0 ? 0 : -EBUSY;
291}
292
293void cxl_adapter_context_put(struct cxl *adapter)
294{
295 atomic_dec_if_positive(&adapter->contexts_num);
296}
297
298int cxl_adapter_context_lock(struct cxl *adapter)
299{
300 int rc;
301 /* no active contexts -> contexts_num == 0 */
302 rc = atomic_cmpxchg(&adapter->contexts_num, 0, -1);
303 return rc ? -EBUSY : 0;
304}
305
306void cxl_adapter_context_unlock(struct cxl *adapter)
307{
308 int val = atomic_cmpxchg(&adapter->contexts_num, -1, 0);
309
310 /*
311 * contexts lock taken -> contexts_num == -1
312 * If not true then show a warning and force reset the lock.
313 * This will happen when context_unlock was requested without
314 * doing a context_lock.
315 */
316 if (val != -1) {
317 atomic_set(&adapter->contexts_num, 0);
318 WARN(1, "Adapter context unlocked with %d active contexts",
319 val);
320 }
321}
322
323static int __init init_cxl(void)
324{
325 int rc = 0;
326
327 if ((rc = cxl_file_init()))
328 return rc;
329
330 cxl_debugfs_init();
331
332 /*
333 * we don't register the callback on P9. slb callack is only
334 * used for the PSL8 MMU and CX4.
335 */
336 if (cxl_is_power8()) {
337 rc = register_cxl_calls(&cxl_calls);
338 if (rc)
339 goto err;
340 }
341
342 if (cpu_has_feature(CPU_FTR_HVMODE)) {
343 cxl_ops = &cxl_native_ops;
344 rc = pci_register_driver(&cxl_pci_driver);
345 }
346#ifdef CONFIG_PPC_PSERIES
347 else {
348 cxl_ops = &cxl_guest_ops;
349 rc = platform_driver_register(&cxl_of_driver);
350 }
351#endif
352 if (rc)
353 goto err1;
354
355 return 0;
356err1:
357 if (cxl_is_power8())
358 unregister_cxl_calls(&cxl_calls);
359err:
360 cxl_debugfs_exit();
361 cxl_file_exit();
362
363 return rc;
364}
365
366static void exit_cxl(void)
367{
368 if (cpu_has_feature(CPU_FTR_HVMODE))
369 pci_unregister_driver(&cxl_pci_driver);
370#ifdef CONFIG_PPC_PSERIES
371 else
372 platform_driver_unregister(&cxl_of_driver);
373#endif
374
375 cxl_debugfs_exit();
376 cxl_file_exit();
377 if (cxl_is_power8())
378 unregister_cxl_calls(&cxl_calls);
379 idr_destroy(&cxl_adapter_idr);
380}
381
382module_init(init_cxl);
383module_exit(exit_cxl);
384
385MODULE_DESCRIPTION("IBM Coherent Accelerator");
386MODULE_AUTHOR("Ian Munsie <imunsie@au1.ibm.com>");
387MODULE_LICENSE("GPL");