]>
Commit | Line | Data |
---|---|---|
2874c5fd | 1 | // SPDX-License-Identifier: GPL-2.0-or-later |
f204e0b8 IM |
2 | /* |
3 | * Copyright 2014 IBM Corp. | |
f204e0b8 IM |
4 | */ |
5 | ||
6 | #include <linux/module.h> | |
7 | #include <linux/kernel.h> | |
8 | #include <linux/bitmap.h> | |
9 | #include <linux/sched.h> | |
10 | #include <linux/pid.h> | |
11 | #include <linux/fs.h> | |
12 | #include <linux/mm.h> | |
13 | #include <linux/debugfs.h> | |
14 | #include <linux/slab.h> | |
15 | #include <linux/idr.h> | |
6dd2d234 | 16 | #include <linux/sched/mm.h> |
03b8abed | 17 | #include <linux/mmu_context.h> |
f204e0b8 IM |
18 | #include <asm/cputable.h> |
19 | #include <asm/current.h> | |
20 | #include <asm/copro.h> | |
21 | ||
22 | #include "cxl.h" | |
23 | ||
24 | /* | |
25 | * Allocates space for a CXL context. | |
26 | */ | |
27 | struct cxl_context *cxl_context_alloc(void) | |
28 | { | |
29 | return kzalloc(sizeof(struct cxl_context), GFP_KERNEL); | |
30 | } | |
31 | ||
32 | /* | |
33 | * Initialises a CXL context. | |
34 | */ | |
bdecf76e | 35 | int cxl_context_init(struct cxl_context *ctx, struct cxl_afu *afu, bool master) |
f204e0b8 IM |
36 | { |
37 | int i; | |
38 | ||
f204e0b8 IM |
39 | ctx->afu = afu; |
40 | ctx->master = master; | |
6dd2d234 | 41 | ctx->pid = NULL; /* Set in start work ioctl */ |
b123429e | 42 | mutex_init(&ctx->mapping_lock); |
bdecf76e | 43 | ctx->mapping = NULL; |
b1db5513 CL |
44 | ctx->tidr = 0; |
45 | ctx->assign_tidr = false; | |
f204e0b8 | 46 | |
797625de | 47 | if (cxl_is_power8()) { |
abd1d99b CL |
48 | spin_lock_init(&ctx->sste_lock); |
49 | ||
50 | /* | |
51 | * Allocate the segment table before we put it in the IDR so that we | |
52 | * can always access it when dereferenced from IDR. For the same | |
53 | * reason, the segment table is only destroyed after the context is | |
54 | * removed from the IDR. Access to this in the IOCTL is protected by | |
55 | * Linux filesytem symantics (can't IOCTL until open is complete). | |
56 | */ | |
57 | i = cxl_alloc_sst(ctx); | |
58 | if (i) | |
59 | return i; | |
60 | } | |
f204e0b8 IM |
61 | |
62 | INIT_WORK(&ctx->fault_work, cxl_handle_fault); | |
63 | ||
64 | init_waitqueue_head(&ctx->wq); | |
65 | spin_lock_init(&ctx->lock); | |
66 | ||
67 | ctx->irq_bitmap = NULL; | |
68 | ctx->pending_irq = false; | |
69 | ctx->pending_fault = false; | |
70 | ctx->pending_afu_err = false; | |
71 | ||
f5c9df9a IM |
72 | INIT_LIST_HEAD(&ctx->irq_names); |
73 | ||
f204e0b8 IM |
74 | /* |
75 | * When we have to destroy all contexts in cxl_context_detach_all() we | |
76 | * end up with afu_release_irqs() called from inside a | |
77 | * idr_for_each_entry(). Hence we need to make sure that anything | |
78 | * dereferenced from this IDR is ok before we allocate the IDR here. | |
79 | * This clears out the IRQ ranges to ensure this. | |
80 | */ | |
81 | for (i = 0; i < CXL_IRQ_RANGES; i++) | |
82 | ctx->irqs.range[i] = 0; | |
83 | ||
84 | mutex_init(&ctx->status_mutex); | |
85 | ||
86 | ctx->status = OPENED; | |
87 | ||
88 | /* | |
89 | * Allocating IDR! We better make sure everything's setup that | |
90 | * dereferences from it. | |
91 | */ | |
ee41d11d | 92 | mutex_lock(&afu->contexts_lock); |
f204e0b8 | 93 | idr_preload(GFP_KERNEL); |
f3988ca4 | 94 | i = idr_alloc(&ctx->afu->contexts_idr, ctx, 0, |
f204e0b8 | 95 | ctx->afu->num_procs, GFP_NOWAIT); |
f204e0b8 | 96 | idr_preload_end(); |
ee41d11d | 97 | mutex_unlock(&afu->contexts_lock); |
f204e0b8 IM |
98 | if (i < 0) |
99 | return i; | |
100 | ||
101 | ctx->pe = i; | |
14baf4d9 | 102 | if (cpu_has_feature(CPU_FTR_HVMODE)) { |
cbffa3a5 | 103 | ctx->elem = &ctx->afu->native->spa[i]; |
14baf4d9 CL |
104 | ctx->external_pe = ctx->pe; |
105 | } else { | |
106 | ctx->external_pe = -1; /* assigned when attaching */ | |
107 | } | |
f204e0b8 | 108 | ctx->pe_inserted = false; |
1b5df59e VJ |
109 | |
110 | /* | |
111 | * take a ref on the afu so that it stays alive at-least till | |
112 | * this context is reclaimed inside reclaim_ctx. | |
113 | */ | |
114 | cxl_afu_get(afu); | |
f204e0b8 IM |
115 | return 0; |
116 | } | |
117 | ||
bdecf76e FB |
118 | void cxl_context_set_mapping(struct cxl_context *ctx, |
119 | struct address_space *mapping) | |
120 | { | |
121 | mutex_lock(&ctx->mapping_lock); | |
122 | ctx->mapping = mapping; | |
123 | mutex_unlock(&ctx->mapping_lock); | |
124 | } | |
125 | ||
a5a0b45e | 126 | static vm_fault_t cxl_mmap_fault(struct vm_fault *vmf) |
0712dc7e | 127 | { |
11bac800 | 128 | struct vm_area_struct *vma = vmf->vma; |
0712dc7e | 129 | struct cxl_context *ctx = vma->vm_file->private_data; |
0712dc7e | 130 | u64 area, offset; |
a5a0b45e | 131 | vm_fault_t ret; |
0712dc7e IM |
132 | |
133 | offset = vmf->pgoff << PAGE_SHIFT; | |
134 | ||
135 | pr_devel("%s: pe: %i address: 0x%lx offset: 0x%llx\n", | |
1a29d85e | 136 | __func__, ctx->pe, vmf->address, offset); |
0712dc7e IM |
137 | |
138 | if (ctx->afu->current_mode == CXL_MODE_DEDICATED) { | |
139 | area = ctx->afu->psn_phys; | |
10a5894f | 140 | if (offset >= ctx->afu->adapter->ps_size) |
0712dc7e IM |
141 | return VM_FAULT_SIGBUS; |
142 | } else { | |
143 | area = ctx->psn_phys; | |
10a5894f | 144 | if (offset >= ctx->psn_size) |
0712dc7e IM |
145 | return VM_FAULT_SIGBUS; |
146 | } | |
147 | ||
148 | mutex_lock(&ctx->status_mutex); | |
149 | ||
150 | if (ctx->status != STARTED) { | |
151 | mutex_unlock(&ctx->status_mutex); | |
152 | pr_devel("%s: Context not started, failing problem state access\n", __func__); | |
d9232a3d IM |
153 | if (ctx->mmio_err_ff) { |
154 | if (!ctx->ff_page) { | |
155 | ctx->ff_page = alloc_page(GFP_USER); | |
156 | if (!ctx->ff_page) | |
157 | return VM_FAULT_OOM; | |
158 | memset(page_address(ctx->ff_page), 0xff, PAGE_SIZE); | |
159 | } | |
160 | get_page(ctx->ff_page); | |
161 | vmf->page = ctx->ff_page; | |
162 | vma->vm_page_prot = pgprot_cached(vma->vm_page_prot); | |
163 | return 0; | |
164 | } | |
0712dc7e IM |
165 | return VM_FAULT_SIGBUS; |
166 | } | |
167 | ||
a5a0b45e | 168 | ret = vmf_insert_pfn(vma, vmf->address, (area + offset) >> PAGE_SHIFT); |
0712dc7e IM |
169 | |
170 | mutex_unlock(&ctx->status_mutex); | |
171 | ||
a5a0b45e | 172 | return ret; |
0712dc7e IM |
173 | } |
174 | ||
175 | static const struct vm_operations_struct cxl_mmap_vmops = { | |
176 | .fault = cxl_mmap_fault, | |
177 | }; | |
178 | ||
f204e0b8 IM |
179 | /* |
180 | * Map a per-context mmio space into the given vma. | |
181 | */ | |
182 | int cxl_context_iomap(struct cxl_context *ctx, struct vm_area_struct *vma) | |
183 | { | |
5caaf534 | 184 | u64 start = vma->vm_pgoff << PAGE_SHIFT; |
f204e0b8 | 185 | u64 len = vma->vm_end - vma->vm_start; |
5caaf534 IM |
186 | |
187 | if (ctx->afu->current_mode == CXL_MODE_DEDICATED) { | |
188 | if (start + len > ctx->afu->adapter->ps_size) | |
189 | return -EINVAL; | |
f24be42a | 190 | |
797625de | 191 | if (cxl_is_power9()) { |
f24be42a CL |
192 | /* |
193 | * Make sure there is a valid problem state | |
194 | * area space for this AFU. | |
195 | */ | |
196 | if (ctx->master && !ctx->afu->psa) { | |
197 | pr_devel("AFU doesn't support mmio space\n"); | |
198 | return -EINVAL; | |
199 | } | |
200 | ||
201 | /* Can't mmap until the AFU is enabled */ | |
202 | if (!ctx->afu->enabled) | |
203 | return -EBUSY; | |
204 | } | |
5caaf534 IM |
205 | } else { |
206 | if (start + len > ctx->psn_size) | |
207 | return -EINVAL; | |
f204e0b8 | 208 | |
f24be42a | 209 | /* Make sure there is a valid per process space for this AFU */ |
0712dc7e IM |
210 | if ((ctx->master && !ctx->afu->psa) || (!ctx->afu->pp_psa)) { |
211 | pr_devel("AFU doesn't support mmio space\n"); | |
212 | return -EINVAL; | |
213 | } | |
f204e0b8 | 214 | |
0712dc7e IM |
215 | /* Can't mmap until the AFU is enabled */ |
216 | if (!ctx->afu->enabled) | |
217 | return -EBUSY; | |
f204e0b8 IM |
218 | } |
219 | ||
f204e0b8 IM |
220 | pr_devel("%s: mmio physical: %llx pe: %i master:%i\n", __func__, |
221 | ctx->psn_phys, ctx->pe , ctx->master); | |
222 | ||
0712dc7e | 223 | vma->vm_flags |= VM_IO | VM_PFNMAP; |
f204e0b8 | 224 | vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot); |
0712dc7e IM |
225 | vma->vm_ops = &cxl_mmap_vmops; |
226 | return 0; | |
f204e0b8 IM |
227 | } |
228 | ||
229 | /* | |
230 | * Detach a context from the hardware. This disables interrupts and doesn't | |
231 | * return until all outstanding interrupts for this context have completed. The | |
232 | * hardware should no longer access *ctx after this has returned. | |
233 | */ | |
eda3693c | 234 | int __detach_context(struct cxl_context *ctx) |
f204e0b8 IM |
235 | { |
236 | enum cxl_context_status status; | |
237 | ||
238 | mutex_lock(&ctx->status_mutex); | |
239 | status = ctx->status; | |
240 | ctx->status = CLOSED; | |
241 | mutex_unlock(&ctx->status_mutex); | |
242 | if (status != STARTED) | |
eda3693c | 243 | return -EBUSY; |
f204e0b8 | 244 | |
0b3f9c75 DA |
245 | /* Only warn if we detached while the link was OK. |
246 | * If detach fails when hw is down, we don't care. | |
247 | */ | |
5be587b1 | 248 | WARN_ON(cxl_ops->detach_process(ctx) && |
0d400f77 | 249 | cxl_ops->link_ok(ctx->afu->adapter, ctx->afu)); |
7bb5d91a | 250 | flush_work(&ctx->fault_work); /* Only needed for dedicated process */ |
7b8ad495 | 251 | |
2bc79ffc MN |
252 | /* |
253 | * Wait until no further interrupts are presented by the PSL | |
254 | * for this context. | |
255 | */ | |
256 | if (cxl_ops->irq_wait) | |
257 | cxl_ops->irq_wait(ctx); | |
258 | ||
7b8ad495 | 259 | /* release the reference to the group leader and mm handling pid */ |
7bb5d91a | 260 | put_pid(ctx->pid); |
7b8ad495 | 261 | |
7bb5d91a | 262 | cxl_ctx_put(); |
70b565bb VJ |
263 | |
264 | /* Decrease the attached context count on the adapter */ | |
265 | cxl_adapter_context_put(ctx->afu->adapter); | |
6dd2d234 CL |
266 | |
267 | /* Decrease the mm count on the context */ | |
268 | cxl_context_mm_count_put(ctx); | |
03b8abed FB |
269 | if (ctx->mm) |
270 | mm_context_remove_copro(ctx->mm); | |
6dd2d234 CL |
271 | ctx->mm = NULL; |
272 | ||
eda3693c | 273 | return 0; |
f204e0b8 IM |
274 | } |
275 | ||
276 | /* | |
277 | * Detach the given context from the AFU. This doesn't actually | |
278 | * free the context but it should stop the context running in hardware | |
279 | * (ie. prevent this context from generating any further interrupts | |
280 | * so that it can be freed). | |
281 | */ | |
282 | void cxl_context_detach(struct cxl_context *ctx) | |
283 | { | |
eda3693c MN |
284 | int rc; |
285 | ||
286 | rc = __detach_context(ctx); | |
287 | if (rc) | |
288 | return; | |
289 | ||
290 | afu_release_irqs(ctx, ctx); | |
eda3693c | 291 | wake_up_all(&ctx->wq); |
f204e0b8 IM |
292 | } |
293 | ||
294 | /* | |
295 | * Detach all contexts on the given AFU. | |
296 | */ | |
297 | void cxl_context_detach_all(struct cxl_afu *afu) | |
298 | { | |
299 | struct cxl_context *ctx; | |
300 | int tmp; | |
301 | ||
ee41d11d IM |
302 | mutex_lock(&afu->contexts_lock); |
303 | idr_for_each_entry(&afu->contexts_idr, ctx, tmp) { | |
f204e0b8 IM |
304 | /* |
305 | * Anything done in here needs to be setup before the IDR is | |
306 | * created and torn down after the IDR removed | |
307 | */ | |
eda3693c | 308 | cxl_context_detach(ctx); |
0712dc7e IM |
309 | |
310 | /* | |
311 | * We are force detaching - remove any active PSA mappings so | |
312 | * userspace cannot interfere with the card if it comes back. | |
313 | * Easiest way to exercise this is to unbind and rebind the | |
314 | * driver via sysfs while it is in use. | |
315 | */ | |
316 | mutex_lock(&ctx->mapping_lock); | |
317 | if (ctx->mapping) | |
318 | unmap_mapping_range(ctx->mapping, 0, 0, 1); | |
319 | mutex_unlock(&ctx->mapping_lock); | |
ee41d11d IM |
320 | } |
321 | mutex_unlock(&afu->contexts_lock); | |
f204e0b8 IM |
322 | } |
323 | ||
8ac75b96 | 324 | static void reclaim_ctx(struct rcu_head *rcu) |
f204e0b8 | 325 | { |
8ac75b96 | 326 | struct cxl_context *ctx = container_of(rcu, struct cxl_context, rcu); |
f204e0b8 | 327 | |
797625de | 328 | if (cxl_is_power8()) |
abd1d99b | 329 | free_page((u64)ctx->sstp); |
d9232a3d IM |
330 | if (ctx->ff_page) |
331 | __free_page(ctx->ff_page); | |
f204e0b8 IM |
332 | ctx->sstp = NULL; |
333 | ||
1050e689 | 334 | kfree(ctx->irq_bitmap); |
52adee58 | 335 | |
1b5df59e VJ |
336 | /* Drop ref to the afu device taken during cxl_context_init */ |
337 | cxl_afu_put(ctx->afu); | |
338 | ||
f204e0b8 IM |
339 | kfree(ctx); |
340 | } | |
8ac75b96 IM |
341 | |
342 | void cxl_context_free(struct cxl_context *ctx) | |
343 | { | |
bdecf76e FB |
344 | if (ctx->kernelapi && ctx->mapping) |
345 | cxl_release_mapping(ctx); | |
8ac75b96 IM |
346 | mutex_lock(&ctx->afu->contexts_lock); |
347 | idr_remove(&ctx->afu->contexts_idr, ctx->pe); | |
348 | mutex_unlock(&ctx->afu->contexts_lock); | |
349 | call_rcu(&ctx->rcu, reclaim_ctx); | |
350 | } | |
6dd2d234 CL |
351 | |
352 | void cxl_context_mm_count_get(struct cxl_context *ctx) | |
353 | { | |
354 | if (ctx->mm) | |
355 | atomic_inc(&ctx->mm->mm_count); | |
356 | } | |
357 | ||
358 | void cxl_context_mm_count_put(struct cxl_context *ctx) | |
359 | { | |
360 | if (ctx->mm) | |
361 | mmdrop(ctx->mm); | |
362 | } |