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
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	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
76static 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
103static struct cxl_calls cxl_calls = {
104	.cxl_slbia = cxl_slbia_core,
105	.owner = THIS_MODULE,
106};
107
108int 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 */
158void 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 */
184struct 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
196static 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
213void cxl_remove_adapter_nr(struct cxl *adapter)
214{
215	idr_remove(&cxl_adapter_idr, adapter->adapter_num);
216}
217
218struct 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;
237err2:
238	cxl_remove_adapter_nr(adapter);
239err1:
240	kfree(adapter);
241	return NULL;
242}
243
244struct 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
265int 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
278int 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
286void cxl_adapter_context_put(struct cxl *adapter)
287{
288	atomic_dec_if_positive(&adapter->contexts_num);
289}
290
291int 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
299void 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
316static 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;
352err1:
353	if (cxl_is_power8())
354		unregister_cxl_calls(&cxl_calls);
355err:
356	cxl_debugfs_exit();
357	cxl_file_exit();
358
359	return rc;
360}
361
362static 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
378module_init(init_cxl);
379module_exit(exit_cxl);
380
381MODULE_DESCRIPTION("IBM Coherent Accelerator");
382MODULE_AUTHOR("Ian Munsie <imunsie@au1.ibm.com>");
383MODULE_LICENSE("GPL");
384