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/sched/task.h>
 19
 20#include <asm/cputable.h>
 21#include <asm/mmu.h>
 22#include <misc/cxl-base.h>
 23
 24#include "cxl.h"
 25#include "trace.h"
 26
 27static DEFINE_SPINLOCK(adapter_idr_lock);
 28static DEFINE_IDR(cxl_adapter_idr);
 29
 30uint cxl_verbose;
 31module_param_named(verbose, cxl_verbose, uint, 0600);
 32MODULE_PARM_DESC(verbose, "Enable verbose dmesg output");
 33
 34const struct cxl_backend_ops *cxl_ops;
 35
 36int cxl_afu_slbia(struct cxl_afu *afu)
 37{
 38	unsigned long timeout = jiffies + (HZ * CXL_TIMEOUT);
 39
 40	pr_devel("cxl_afu_slbia issuing SLBIA command\n");
 41	cxl_p2n_write(afu, CXL_SLBIA_An, CXL_TLB_SLB_IQ_ALL);
 42	while (cxl_p2n_read(afu, CXL_SLBIA_An) & CXL_TLB_SLB_P) {
 43		if (time_after_eq(jiffies, timeout)) {
 44			dev_warn(&afu->dev, "WARNING: CXL AFU SLBIA timed out!\n");
 45			return -EBUSY;
 46		}
 47		/* If the adapter has gone down, we can assume that we
 48		 * will PERST it and that will invalidate everything.
 49		 */
 50		if (!cxl_ops->link_ok(afu->adapter, afu))
 51			return -EIO;
 52		cpu_relax();
 53	}
 54	return 0;
 55}
 56
 57static inline void _cxl_slbia(struct cxl_context *ctx, struct mm_struct *mm)
 58{
 59	unsigned long flags;
 60
 61	if (ctx->mm != mm)
 62		return;
 63
 64	pr_devel("%s matched mm - card: %i afu: %i pe: %i\n", __func__,
 65		 ctx->afu->adapter->adapter_num, ctx->afu->slice, ctx->pe);
 66
 67	spin_lock_irqsave(&ctx->sste_lock, flags);
 68	trace_cxl_slbia(ctx);
 69	memset(ctx->sstp, 0, ctx->sst_size);
 70	spin_unlock_irqrestore(&ctx->sste_lock, flags);
 71	mb();
 72	cxl_afu_slbia(ctx->afu);
 73}
 74
 75static inline void cxl_slbia_core(struct mm_struct *mm)
 76{
 77	struct cxl *adapter;
 78	struct cxl_afu *afu;
 79	struct cxl_context *ctx;
 80	int card, slice, id;
 81
 82	pr_devel("%s called\n", __func__);
 83
 84	spin_lock(&adapter_idr_lock);
 85	idr_for_each_entry(&cxl_adapter_idr, adapter, card) {
 86		/* XXX: Make this lookup faster with link from mm to ctx */
 87		spin_lock(&adapter->afu_list_lock);
 88		for (slice = 0; slice < adapter->slices; slice++) {
 89			afu = adapter->afu[slice];
 90			if (!afu || !afu->enabled)
 91				continue;
 92			rcu_read_lock();
 93			idr_for_each_entry(&afu->contexts_idr, ctx, id)
 94				_cxl_slbia(ctx, mm);
 95			rcu_read_unlock();
 96		}
 97		spin_unlock(&adapter->afu_list_lock);
 98	}
 99	spin_unlock(&adapter_idr_lock);
100}
101
102static struct cxl_calls cxl_calls = {
103	.cxl_slbia = cxl_slbia_core,
104	.owner = THIS_MODULE,
105};
106
107int cxl_alloc_sst(struct cxl_context *ctx)
108{
109	unsigned long vsid;
110	u64 ea_mask, size, sstp0, sstp1;
111
112	sstp0 = 0;
113	sstp1 = 0;
114
115	ctx->sst_size = PAGE_SIZE;
116	ctx->sst_lru = 0;
117	ctx->sstp = (struct cxl_sste *)get_zeroed_page(GFP_KERNEL);
118	if (!ctx->sstp) {
119		pr_err("cxl_alloc_sst: Unable to allocate segment table\n");
120		return -ENOMEM;
121	}
122	pr_devel("SSTP allocated at 0x%p\n", ctx->sstp);
123
124	vsid  = get_kernel_vsid((u64)ctx->sstp, mmu_kernel_ssize) << 12;
125
126	sstp0 |= (u64)mmu_kernel_ssize << CXL_SSTP0_An_B_SHIFT;
127	sstp0 |= (SLB_VSID_KERNEL | mmu_psize_defs[mmu_linear_psize].sllp) << 50;
128
129	size = (((u64)ctx->sst_size >> 8) - 1) << CXL_SSTP0_An_SegTableSize_SHIFT;
130	if (unlikely(size & ~CXL_SSTP0_An_SegTableSize_MASK)) {
131		WARN(1, "Impossible segment table size\n");
132		return -EINVAL;
133	}
134	sstp0 |= size;
135
136	if (mmu_kernel_ssize == MMU_SEGSIZE_256M)
137		ea_mask = 0xfffff00ULL;
138	else
139		ea_mask = 0xffffffff00ULL;
140
141	sstp0 |=  vsid >>     (50-14);  /*   Top 14 bits of VSID */
142	sstp1 |= (vsid << (64-(50-14))) & ~ea_mask;
143	sstp1 |= (u64)ctx->sstp & ea_mask;
144	sstp1 |= CXL_SSTP1_An_V;
145
146	pr_devel("Looked up %#llx: slbfee. %#llx (ssize: %x, vsid: %#lx), copied to SSTP0: %#llx, SSTP1: %#llx\n",
147			(u64)ctx->sstp, (u64)ctx->sstp & ESID_MASK, mmu_kernel_ssize, vsid, sstp0, sstp1);
148
149	/* Store calculated sstp hardware points for use later */
150	ctx->sstp0 = sstp0;
151	ctx->sstp1 = sstp1;
152
153	return 0;
154}
155
156/* print buffer content as integers when debugging */
157void cxl_dump_debug_buffer(void *buf, size_t buf_len)
158{
159#ifdef DEBUG
160	int i, *ptr;
161
162	/*
163	 * We want to regroup up to 4 integers per line, which means they
164	 * need to be in the same pr_devel() statement
165	 */
166	ptr = (int *) buf;
167	for (i = 0; i * 4 < buf_len; i += 4) {
168		if ((i + 3) * 4 < buf_len)
169			pr_devel("%.8x %.8x %.8x %.8x\n", ptr[i], ptr[i + 1],
170				ptr[i + 2], ptr[i + 3]);
171		else if ((i + 2) * 4 < buf_len)
172			pr_devel("%.8x %.8x %.8x\n", ptr[i], ptr[i + 1],
173				ptr[i + 2]);
174		else if ((i + 1) * 4 < buf_len)
175			pr_devel("%.8x %.8x\n", ptr[i], ptr[i + 1]);
176		else
177			pr_devel("%.8x\n", ptr[i]);
178	}
179#endif /* DEBUG */
180}
181
182/* Find a CXL adapter by it's number and increase it's refcount */
183struct cxl *get_cxl_adapter(int num)
184{
185	struct cxl *adapter;
186
187	spin_lock(&adapter_idr_lock);
188	if ((adapter = idr_find(&cxl_adapter_idr, num)))
189		get_device(&adapter->dev);
190	spin_unlock(&adapter_idr_lock);
191
192	return adapter;
193}
194
195static int cxl_alloc_adapter_nr(struct cxl *adapter)
196{
197	int i;
198
199	idr_preload(GFP_KERNEL);
200	spin_lock(&adapter_idr_lock);
201	i = idr_alloc(&cxl_adapter_idr, adapter, 0, 0, GFP_NOWAIT);
202	spin_unlock(&adapter_idr_lock);
203	idr_preload_end();
204	if (i < 0)
205		return i;
206
207	adapter->adapter_num = i;
208
209	return 0;
210}
211
212void cxl_remove_adapter_nr(struct cxl *adapter)
213{
214	idr_remove(&cxl_adapter_idr, adapter->adapter_num);
215}
216
217struct cxl *cxl_alloc_adapter(void)
218{
219	struct cxl *adapter;
220
221	if (!(adapter = kzalloc(sizeof(struct cxl), GFP_KERNEL)))
222		return NULL;
223
224	spin_lock_init(&adapter->afu_list_lock);
225
226	if (cxl_alloc_adapter_nr(adapter))
227		goto err1;
228
229	if (dev_set_name(&adapter->dev, "card%i", adapter->adapter_num))
230		goto err2;
231
232	/* start with context lock taken */
233	atomic_set(&adapter->contexts_num, -1);
234
235	return adapter;
236err2:
237	cxl_remove_adapter_nr(adapter);
238err1:
239	kfree(adapter);
240	return NULL;
241}
242
243struct cxl_afu *cxl_alloc_afu(struct cxl *adapter, int slice)
244{
245	struct cxl_afu *afu;
246
247	if (!(afu = kzalloc(sizeof(struct cxl_afu), GFP_KERNEL)))
248		return NULL;
249
250	afu->adapter = adapter;
251	afu->dev.parent = &adapter->dev;
252	afu->dev.release = cxl_ops->release_afu;
253	afu->slice = slice;
254	idr_init(&afu->contexts_idr);
255	mutex_init(&afu->contexts_lock);
256	spin_lock_init(&afu->afu_cntl_lock);
257	atomic_set(&afu->configured_state, -1);
258	afu->prefault_mode = CXL_PREFAULT_NONE;
259	afu->irqs_max = afu->adapter->user_irqs;
260
261	return afu;
262}
263
264int cxl_afu_select_best_mode(struct cxl_afu *afu)
265{
266	if (afu->modes_supported & CXL_MODE_DIRECTED)
267		return cxl_ops->afu_activate_mode(afu, CXL_MODE_DIRECTED);
268
269	if (afu->modes_supported & CXL_MODE_DEDICATED)
270		return cxl_ops->afu_activate_mode(afu, CXL_MODE_DEDICATED);
271
272	dev_warn(&afu->dev, "No supported programming modes available\n");
273	/* We don't fail this so the user can inspect sysfs */
274	return 0;
275}
276
277int cxl_adapter_context_get(struct cxl *adapter)
278{
279	int rc;
280
281	rc = atomic_inc_unless_negative(&adapter->contexts_num);
282	return rc ? 0 : -EBUSY;
283}
284
285void cxl_adapter_context_put(struct cxl *adapter)
286{
287	atomic_dec_if_positive(&adapter->contexts_num);
288}
289
290int cxl_adapter_context_lock(struct cxl *adapter)
291{
292	int rc;
293	/* no active contexts -> contexts_num == 0 */
294	rc = atomic_cmpxchg(&adapter->contexts_num, 0, -1);
295	return rc ? -EBUSY : 0;
296}
297
298void cxl_adapter_context_unlock(struct cxl *adapter)
299{
300	int val = atomic_cmpxchg(&adapter->contexts_num, -1, 0);
301
302	/*
303	 * contexts lock taken -> contexts_num == -1
304	 * If not true then show a warning and force reset the lock.
305	 * This will happen when context_unlock was requested without
306	 * doing a context_lock.
307	 */
308	if (val != -1) {
309		atomic_set(&adapter->contexts_num, 0);
310		WARN(1, "Adapter context unlocked with %d active contexts",
311		     val);
312	}
313}
314
315static int __init init_cxl(void)
316{
317	int rc = 0;
318
319	if (!tlbie_capable)
320		return -EINVAL;
321
322	if ((rc = cxl_file_init()))
323		return rc;
324
325	cxl_debugfs_init();
326
327	/*
328	 * we don't register the callback on P9. slb callack is only
329	 * used for the PSL8 MMU and CX4.
330	 */
331	if (cxl_is_power8()) {
332		rc = register_cxl_calls(&cxl_calls);
333		if (rc)
334			goto err;
335	}
336
337	if (cpu_has_feature(CPU_FTR_HVMODE)) {
338		cxl_ops = &cxl_native_ops;
339		rc = pci_register_driver(&cxl_pci_driver);
340	}
341#ifdef CONFIG_PPC_PSERIES
342	else {
343		cxl_ops = &cxl_guest_ops;
344		rc = platform_driver_register(&cxl_of_driver);
345	}
346#endif
347	if (rc)
348		goto err1;
349
350	return 0;
351err1:
352	if (cxl_is_power8())
353		unregister_cxl_calls(&cxl_calls);
354err:
355	cxl_debugfs_exit();
356	cxl_file_exit();
357
358	return rc;
359}
360
361static void exit_cxl(void)
362{
363	if (cpu_has_feature(CPU_FTR_HVMODE))
364		pci_unregister_driver(&cxl_pci_driver);
365#ifdef CONFIG_PPC_PSERIES
366	else
367		platform_driver_unregister(&cxl_of_driver);
368#endif
369
370	cxl_debugfs_exit();
371	cxl_file_exit();
372	if (cxl_is_power8())
373		unregister_cxl_calls(&cxl_calls);
374	idr_destroy(&cxl_adapter_idr);
375}
376
377module_init(init_cxl);
378module_exit(exit_cxl);
379
380MODULE_DESCRIPTION("IBM Coherent Accelerator");
381MODULE_AUTHOR("Ian Munsie <imunsie@au1.ibm.com>");
382MODULE_LICENSE("GPL");