source: src/linux/universal/linux-4.9/drivers/misc/cxl/main.c @ 31662

Last change on this file since 31662 was 31662, checked in by brainslayer, 3 months ago

use new squashfs in all kernels

File size: 9.2 KB
Line 
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
28static DEFINE_SPINLOCK(adapter_idr_lock);
29static DEFINE_IDR(cxl_adapter_idr);
30
31uint cxl_verbose;
32module_param_named(verbose, cxl_verbose, uint, 0600);
33MODULE_PARM_DESC(verbose, "Enable verbose dmesg output");
34
35const struct cxl_backend_ops *cxl_ops;
36
37int 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
58static 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);
80out_put:
81        put_task_struct(task);
82}
83
84static 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
111static 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
121int 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 */
171void 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 */
197struct 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
209static 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
226void cxl_remove_adapter_nr(struct cxl *adapter)
227{
228        idr_remove(&cxl_adapter_idr, adapter->adapter_num);
229}
230
231struct 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        /* start with context lock taken */
247        atomic_set(&adapter->contexts_num, -1);
248
249        return adapter;
250err2:
251        cxl_remove_adapter_nr(adapter);
252err1:
253        kfree(adapter);
254        return NULL;
255}
256
257struct cxl_afu *cxl_alloc_afu(struct cxl *adapter, int slice)
258{
259        struct cxl_afu *afu;
260
261        if (!(afu = kzalloc(sizeof(struct cxl_afu), GFP_KERNEL)))
262                return NULL;
263
264        afu->adapter = adapter;
265        afu->dev.parent = &adapter->dev;
266        afu->dev.release = cxl_ops->release_afu;
267        afu->slice = slice;
268        idr_init(&afu->contexts_idr);
269        mutex_init(&afu->contexts_lock);
270        spin_lock_init(&afu->afu_cntl_lock);
271        atomic_set(&afu->configured_state, -1);
272        afu->prefault_mode = CXL_PREFAULT_NONE;
273        afu->irqs_max = afu->adapter->user_irqs;
274
275        return afu;
276}
277
278int cxl_afu_select_best_mode(struct cxl_afu *afu)
279{
280        if (afu->modes_supported & CXL_MODE_DIRECTED)
281                return cxl_ops->afu_activate_mode(afu, CXL_MODE_DIRECTED);
282
283        if (afu->modes_supported & CXL_MODE_DEDICATED)
284                return cxl_ops->afu_activate_mode(afu, CXL_MODE_DEDICATED);
285
286        dev_warn(&afu->dev, "No supported programming modes available\n");
287        /* We don't fail this so the user can inspect sysfs */
288        return 0;
289}
290
291int cxl_adapter_context_get(struct cxl *adapter)
292{
293        int rc;
294
295        rc = atomic_inc_unless_negative(&adapter->contexts_num);
296        return rc >= 0 ? 0 : -EBUSY;
297}
298
299void cxl_adapter_context_put(struct cxl *adapter)
300{
301        atomic_dec_if_positive(&adapter->contexts_num);
302}
303
304int cxl_adapter_context_lock(struct cxl *adapter)
305{
306        int rc;
307        /* no active contexts -> contexts_num == 0 */
308        rc = atomic_cmpxchg(&adapter->contexts_num, 0, -1);
309        return rc ? -EBUSY : 0;
310}
311
312void cxl_adapter_context_unlock(struct cxl *adapter)
313{
314        int val = atomic_cmpxchg(&adapter->contexts_num, -1, 0);
315
316        /*
317         * contexts lock taken -> contexts_num == -1
318         * If not true then show a warning and force reset the lock.
319         * This will happen when context_unlock was requested without
320         * doing a context_lock.
321         */
322        if (val != -1) {
323                atomic_set(&adapter->contexts_num, 0);
324                WARN(1, "Adapter context unlocked with %d active contexts",
325                     val);
326        }
327}
328
329static int __init init_cxl(void)
330{
331        int rc = 0;
332
333        if ((rc = cxl_file_init()))
334                return rc;
335
336        cxl_debugfs_init();
337
338        if ((rc = register_cxl_calls(&cxl_calls)))
339                goto err;
340
341        if (cpu_has_feature(CPU_FTR_HVMODE)) {
342                cxl_ops = &cxl_native_ops;
343                rc = pci_register_driver(&cxl_pci_driver);
344        }
345#ifdef CONFIG_PPC_PSERIES
346        else {
347                cxl_ops = &cxl_guest_ops;
348                rc = platform_driver_register(&cxl_of_driver);
349        }
350#endif
351        if (rc)
352                goto err1;
353
354        return 0;
355err1:
356        unregister_cxl_calls(&cxl_calls);
357err:
358        cxl_debugfs_exit();
359        cxl_file_exit();
360
361        return rc;
362}
363
364static void exit_cxl(void)
365{
366        if (cpu_has_feature(CPU_FTR_HVMODE))
367                pci_unregister_driver(&cxl_pci_driver);
368#ifdef CONFIG_PPC_PSERIES
369        else
370                platform_driver_unregister(&cxl_of_driver);
371#endif
372
373        cxl_debugfs_exit();
374        cxl_file_exit();
375        unregister_cxl_calls(&cxl_calls);
376        idr_destroy(&cxl_adapter_idr);
377}
378
379module_init(init_cxl);
380module_exit(exit_cxl);
381
382MODULE_DESCRIPTION("IBM Coherent Accelerator");
383MODULE_AUTHOR("Ian Munsie <imunsie@au1.ibm.com>");
384MODULE_LICENSE("GPL");
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