1 /*
2 * Intel MIC Platform Software Stack (MPSS)
3 *
4 * This file is provided under a dual BSD/GPLv2 license. When using or
5 * redistributing this file, you may do so under either license.
6 *
7 * GPL LICENSE SUMMARY
8 *
9 * Copyright(c) 2015 Intel Corporation.
10 *
11 * This program is free software; you can redistribute it and/or modify
12 * it under the terms of version 2 of the GNU General Public License as
13 * published by the Free Software Foundation.
14 *
15 * This program is distributed in the hope that it will be useful, but
16 * WITHOUT ANY WARRANTY; without even the implied warranty of
17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
18 * General Public License for more details.
19 *
20 * BSD LICENSE
21 *
22 * Copyright(c) 2015 Intel Corporation.
23 *
24 * Redistribution and use in source and binary forms, with or without
25 * modification, are permitted provided that the following conditions
26 * are met:
27 *
28 * * Redistributions of source code must retain the above copyright
29 * notice, this list of conditions and the following disclaimer.
30 * * Redistributions in binary form must reproduce the above copyright
31 * notice, this list of conditions and the following disclaimer in
32 * the documentation and/or other materials provided with the
33 * distribution.
34 * * Neither the name of Intel Corporation nor the names of its
35 * contributors may be used to endorse or promote products derived
36 * from this software without specific prior written permission.
37 *
38 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
39 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
40 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
41 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
42 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
43 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
44 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
45 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
46 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
47 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
48 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
49 *
50 * Intel SCIF driver.
51 *
52 */
53 #ifndef SCIF_RMA_H
54 #define SCIF_RMA_H
55
56 #include <linux/intel-iommu.h>
57 #include <linux/mmu_notifier.h>
58
59 #include "../bus/scif_bus.h"
60
61 /* If this bit is set then the mark is a remote fence mark */
62 #define SCIF_REMOTE_FENCE_BIT 31
63 /* Magic value used to indicate a remote fence request */
64 #define SCIF_REMOTE_FENCE BIT_ULL(SCIF_REMOTE_FENCE_BIT)
65
66 #define SCIF_MAX_UNALIGNED_BUF_SIZE (1024 * 1024ULL)
67 #define SCIF_KMEM_UNALIGNED_BUF_SIZE (SCIF_MAX_UNALIGNED_BUF_SIZE + \
68 (L1_CACHE_BYTES << 1))
69
70 #define SCIF_IOVA_START_PFN (1)
71 #define SCIF_IOVA_PFN(addr) ((addr) >> PAGE_SHIFT)
72 #define SCIF_DMA_64BIT_PFN SCIF_IOVA_PFN(DMA_BIT_MASK(64))
73 #define SCIF_DMA_63BIT_PFN SCIF_IOVA_PFN(DMA_BIT_MASK(63))
74
75 /*
76 * struct scif_endpt_rma_info - Per Endpoint Remote Memory Access Information
77 *
78 * @reg_list: List of registration windows for self
79 * @remote_reg_list: List of registration windows for peer
80 * @iovad: Offset generator
81 * @rma_lock: Synchronizes access to self/remote list and also protects the
82 * window from being destroyed while RMAs are in progress.
83 * @tc_lock: Synchronizes access to temporary cached windows list
84 * for SCIF Registration Caching.
85 * @mmn_lock: Synchronizes access to the list of MMU notifiers registered
86 * @tw_refcount: Keeps track of number of outstanding temporary registered
87 * windows created by scif_vreadfrom/scif_vwriteto which have
88 * not been destroyed.
89 * @tcw_refcount: Same as tw_refcount but for temporary cached windows
90 * @tcw_total_pages: Same as tcw_refcount but in terms of pages pinned
91 * @mmn_list: MMU notifier so that we can destroy the windows when required
92 * @fence_refcount: Keeps track of number of outstanding remote fence
93 * requests which have been received by the peer.
94 * @dma_chan: DMA channel used for all DMA transfers for this endpoint.
95 * @async_list_del: Detect asynchronous list entry deletion
96 * @vma_list: List of vmas with remote memory mappings
97 * @markwq: Wait queue used for scif_fence_mark/scif_fence_wait
98 */
99 struct scif_endpt_rma_info {
100 struct list_head reg_list;
101 struct list_head remote_reg_list;
102 struct iova_domain iovad;
103 struct mutex rma_lock;
104 spinlock_t tc_lock;
105 struct mutex mmn_lock;
106 atomic_t tw_refcount;
107 atomic_t tcw_refcount;
108 atomic_t tcw_total_pages;
109 struct list_head mmn_list;
110 atomic_t fence_refcount;
111 struct dma_chan *dma_chan;
112 int async_list_del;
113 struct list_head vma_list;
114 wait_queue_head_t markwq;
115 };
116
117 /*
118 * struct scif_fence_info - used for tracking fence requests
119 *
120 * @state: State of this transfer
121 * @wq: Fences wait on this queue
122 * @dma_mark: Used for storing the DMA mark
123 */
124 struct scif_fence_info {
125 enum scif_msg_state state;
126 struct completion comp;
127 int dma_mark;
128 };
129
130 /*
131 * struct scif_remote_fence_info - used for tracking remote fence requests
132 *
133 * @msg: List of SCIF node QP fence messages
134 * @list: Link to list of remote fence requests
135 */
136 struct scif_remote_fence_info {
137 struct scifmsg msg;
138 struct list_head list;
139 };
140
141 /*
142 * Specifies whether an RMA operation can span across partial windows, a single
143 * window or multiple contiguous windows. Mmaps can span across partial windows.
144 * Unregistration can span across complete windows. scif_get_pages() can span a
145 * single window. A window can also be of type self or peer.
146 */
147 enum scif_window_type {
148 SCIF_WINDOW_PARTIAL,
149 SCIF_WINDOW_SINGLE,
150 SCIF_WINDOW_FULL,
151 SCIF_WINDOW_SELF,
152 SCIF_WINDOW_PEER
153 };
154
155 /* The number of physical addresses that can be stored in a PAGE. */
156 #define SCIF_NR_ADDR_IN_PAGE (0x1000 >> 3)
157
158 /*
159 * struct scif_rma_lookup - RMA lookup data structure for page list transfers
160 *
161 * Store an array of lookup offsets. Each offset in this array maps
162 * one 4K page containing 512 physical addresses i.e. 2MB. 512 such
163 * offsets in a 4K page will correspond to 1GB of registered address space.
164
165 * @lookup: Array of offsets
166 * @offset: DMA offset of lookup array
167 */
168 struct scif_rma_lookup {
169 dma_addr_t *lookup;
170 dma_addr_t offset;
171 };
172
173 /*
174 * struct scif_pinned_pages - A set of pinned pages obtained with
175 * scif_pin_pages() which could be part of multiple registered
176 * windows across different end points.
177 *
178 * @nr_pages: Number of pages which is defined as a s64 instead of an int
179 * to avoid sign extension with buffers >= 2GB
180 * @prot: read/write protections
181 * @map_flags: Flags specified during the pin operation
182 * @ref_count: Reference count bumped in terms of number of pages
183 * @magic: A magic value
184 * @pages: Array of pointers to struct pages populated with get_user_pages(..)
185 */
186 struct scif_pinned_pages {
187 s64 nr_pages;
188 int prot;
189 int map_flags;
190 atomic_t ref_count;
191 u64 magic;
192 struct page **pages;
193 };
194
195 /*
196 * struct scif_status - Stores DMA status update information
197 *
198 * @src_dma_addr: Source buffer DMA address
199 * @val: src location for value to be written to the destination
200 * @ep: SCIF endpoint
201 */
202 struct scif_status {
203 dma_addr_t src_dma_addr;
204 u64 val;
205 struct scif_endpt *ep;
206 };
207
208 /*
209 * struct scif_cb_arg - Stores the argument of the callback func
210 *
211 * @src_dma_addr: Source buffer DMA address
212 * @status: DMA status
213 * @ep: SCIF endpoint
214 */
215 struct scif_cb_arg {
216 dma_addr_t src_dma_addr;
217 struct scif_status *status;
218 struct scif_endpt *ep;
219 };
220
221 /*
222 * struct scif_window - Registration Window for Self and Remote
223 *
224 * @nr_pages: Number of pages which is defined as a s64 instead of an int
225 * to avoid sign extension with buffers >= 2GB
226 * @nr_contig_chunks: Number of contiguous physical chunks
227 * @prot: read/write protections
228 * @ref_count: reference count in terms of number of pages
229 * @magic: Cookie to detect corruption
230 * @offset: registered offset
231 * @va_for_temp: va address that this window represents
232 * @dma_mark: Used to determine if all DMAs against the window are done
233 * @ep: Pointer to EP. Useful for passing EP around with messages to
234 avoid expensive list traversals.
235 * @list: link to list of windows for the endpoint
236 * @type: self or peer window
237 * @peer_window: Pointer to peer window. Useful for sending messages to peer
238 * without requiring an extra list traversal
239 * @unreg_state: unregistration state
240 * @offset_freed: True if the offset has been freed
241 * @temp: True for temporary windows created via scif_vreadfrom/scif_vwriteto
242 * @mm: memory descriptor for the task_struct which initiated the RMA
243 * @st: scatter gather table for DMA mappings with IOMMU enabled
244 * @pinned_pages: The set of pinned_pages backing this window
245 * @alloc_handle: Handle for sending ALLOC_REQ
246 * @regwq: Wait Queue for an registration (N)ACK
247 * @reg_state: Registration state
248 * @unregwq: Wait Queue for an unregistration (N)ACK
249 * @dma_addr_lookup: Lookup for physical addresses used for DMA
250 * @nr_lookup: Number of entries in lookup
251 * @mapped_offset: Offset used to map the window by the peer
252 * @dma_addr: Array of physical addresses used for Mgmt node & MIC initiated DMA
253 * @num_pages: Array specifying number of pages for each physical address
254 */
255 struct scif_window {
256 s64 nr_pages;
257 int nr_contig_chunks;
258 int prot;
259 int ref_count;
260 u64 magic;
261 s64 offset;
262 unsigned long va_for_temp;
263 int dma_mark;
264 u64 ep;
265 struct list_head list;
266 enum scif_window_type type;
267 u64 peer_window;
268 enum scif_msg_state unreg_state;
269 bool offset_freed;
270 bool temp;
271 struct mm_struct *mm;
272 struct sg_table *st;
273 union {
274 struct {
275 struct scif_pinned_pages *pinned_pages;
276 struct scif_allocmsg alloc_handle;
277 wait_queue_head_t regwq;
278 enum scif_msg_state reg_state;
279 wait_queue_head_t unregwq;
280 };
281 struct {
282 struct scif_rma_lookup dma_addr_lookup;
283 struct scif_rma_lookup num_pages_lookup;
284 int nr_lookup;
285 dma_addr_t mapped_offset;
286 };
287 };
288 dma_addr_t *dma_addr;
289 u64 *num_pages;
290 } __packed;
291
292 /*
293 * scif_mmu_notif - SCIF mmu notifier information
294 *
295 * @mmu_notifier ep_mmu_notifier: MMU notifier operations
296 * @tc_reg_list: List of temp registration windows for self
297 * @mm: memory descriptor for the task_struct which initiated the RMA
298 * @ep: SCIF endpoint
299 * @list: link to list of MMU notifier information
300 */
301 struct scif_mmu_notif {
302 #ifdef CONFIG_MMU_NOTIFIER
303 struct mmu_notifier ep_mmu_notifier;
304 #endif
305 struct list_head tc_reg_list;
306 struct mm_struct *mm;
307 struct scif_endpt *ep;
308 struct list_head list;
309 };
310
311 enum scif_rma_dir {
312 SCIF_LOCAL_TO_REMOTE,
313 SCIF_REMOTE_TO_LOCAL
314 };
315
316 extern struct kmem_cache *unaligned_cache;
317 /* Initialize RMA for this EP */
318 void scif_rma_ep_init(struct scif_endpt *ep);
319 /* Check if epd can be uninitialized */
320 int scif_rma_ep_can_uninit(struct scif_endpt *ep);
321 /* Obtain a new offset. Callee must grab RMA lock */
322 int scif_get_window_offset(struct scif_endpt *ep, int flags,
323 s64 offset, int nr_pages, s64 *out_offset);
324 /* Free offset. Callee must grab RMA lock */
325 void scif_free_window_offset(struct scif_endpt *ep,
326 struct scif_window *window, s64 offset);
327 /* Create self registration window */
328 struct scif_window *scif_create_window(struct scif_endpt *ep, int nr_pages,
329 s64 offset, bool temp);
330 /* Destroy self registration window.*/
331 int scif_destroy_window(struct scif_endpt *ep, struct scif_window *window);
332 void scif_unmap_window(struct scif_dev *remote_dev, struct scif_window *window);
333 /* Map pages of self window to Aperture/PCI */
334 int scif_map_window(struct scif_dev *remote_dev,
335 struct scif_window *window);
336 /* Unregister a self window */
337 int scif_unregister_window(struct scif_window *window);
338 /* Destroy remote registration window */
339 void
340 scif_destroy_remote_window(struct scif_window *window);
341 /* remove valid remote memory mappings from process address space */
342 void scif_zap_mmaps(int node);
343 /* Query if any applications have remote memory mappings */
344 bool scif_rma_do_apps_have_mmaps(int node);
345 /* Cleanup remote registration lists for zombie endpoints */
346 void scif_cleanup_rma_for_zombies(int node);
347 /* Reserve a DMA channel for a particular endpoint */
348 int scif_reserve_dma_chan(struct scif_endpt *ep);
349 /* Setup a DMA mark for an endpoint */
350 int _scif_fence_mark(scif_epd_t epd, int *mark);
351 int scif_prog_signal(scif_epd_t epd, off_t offset, u64 val,
352 enum scif_window_type type);
353 void scif_alloc_req(struct scif_dev *scifdev, struct scifmsg *msg);
354 void scif_alloc_gnt_rej(struct scif_dev *scifdev, struct scifmsg *msg);
355 void scif_free_virt(struct scif_dev *scifdev, struct scifmsg *msg);
356 void scif_recv_reg(struct scif_dev *scifdev, struct scifmsg *msg);
357 void scif_recv_unreg(struct scif_dev *scifdev, struct scifmsg *msg);
358 void scif_recv_reg_ack(struct scif_dev *scifdev, struct scifmsg *msg);
359 void scif_recv_reg_nack(struct scif_dev *scifdev, struct scifmsg *msg);
360 void scif_recv_unreg_ack(struct scif_dev *scifdev, struct scifmsg *msg);
361 void scif_recv_unreg_nack(struct scif_dev *scifdev, struct scifmsg *msg);
362 void scif_recv_munmap(struct scif_dev *scifdev, struct scifmsg *msg);
363 void scif_recv_mark(struct scif_dev *scifdev, struct scifmsg *msg);
364 void scif_recv_mark_resp(struct scif_dev *scifdev, struct scifmsg *msg);
365 void scif_recv_wait(struct scif_dev *scifdev, struct scifmsg *msg);
366 void scif_recv_wait_resp(struct scif_dev *scifdev, struct scifmsg *msg);
367 void scif_recv_sig_local(struct scif_dev *scifdev, struct scifmsg *msg);
368 void scif_recv_sig_remote(struct scif_dev *scifdev, struct scifmsg *msg);
369 void scif_recv_sig_resp(struct scif_dev *scifdev, struct scifmsg *msg);
370 void scif_mmu_notif_handler(struct work_struct *work);
371 void scif_rma_handle_remote_fences(void);
372 void scif_rma_destroy_windows(void);
373 void scif_rma_destroy_tcw_invalid(void);
374 int scif_drain_dma_intr(struct scif_hw_dev *sdev, struct dma_chan *chan);
375
376 struct scif_window_iter {
377 s64 offset;
378 int index;
379 };
380
381 static inline void
382 scif_init_window_iter(struct scif_window *window, struct scif_window_iter *iter)
383 {
384 iter->offset = window->offset;
385 iter->index = 0;
386 }
387
388 dma_addr_t scif_off_to_dma_addr(struct scif_window *window, s64 off,
389 size_t *nr_bytes,
390 struct scif_window_iter *iter);
391 static inline
392 dma_addr_t __scif_off_to_dma_addr(struct scif_window *window, s64 off)
393 {
394 return scif_off_to_dma_addr(window, off, NULL, NULL);
395 }
396
397 static inline bool scif_unaligned(off_t src_offset, off_t dst_offset)
398 {
399 src_offset = src_offset & (L1_CACHE_BYTES - 1);
400 dst_offset = dst_offset & (L1_CACHE_BYTES - 1);
401 return !(src_offset == dst_offset);
402 }
403
404 /*
405 * scif_zalloc:
406 * @size: Size of the allocation request.
407 *
408 * Helper API which attempts to allocate zeroed pages via
409 * __get_free_pages(..) first and then falls back on
410 * vzalloc(..) if that fails.
411 */
412 static inline void *scif_zalloc(size_t size)
413 {
414 void *ret = NULL;
415 size_t align = ALIGN(size, PAGE_SIZE);
416
417 if (align && get_order(align) < MAX_ORDER)
418 ret = (void *)__get_free_pages(GFP_KERNEL | __GFP_ZERO,
419 get_order(align));
420 return ret ? ret : vzalloc(align);
421 }
422
423 /*
424 * scif_free:
425 * @addr: Address to be freed.
426 * @size: Size of the allocation.
427 * Helper API which frees memory allocated via scif_zalloc().
428 */
429 static inline void scif_free(void *addr, size_t size)
430 {
431 size_t align = ALIGN(size, PAGE_SIZE);
432
433 if (is_vmalloc_addr(addr))
434 vfree(addr);
435 else
436 free_pages((unsigned long)addr, get_order(align));
437 }
438
439 static inline void scif_get_window(struct scif_window *window, int nr_pages)
440 {
441 window->ref_count += nr_pages;
442 }
443
444 static inline void scif_put_window(struct scif_window *window, int nr_pages)
445 {
446 window->ref_count -= nr_pages;
447 }
448
449 static inline void scif_set_window_ref(struct scif_window *window, int nr_pages)
450 {
451 window->ref_count = nr_pages;
452 }
453
454 static inline void
455 scif_queue_for_cleanup(struct scif_window *window, struct list_head *list)
456 {
457 spin_lock(&scif_info.rmalock);
458 list_add_tail(&window->list, list);
459 spin_unlock(&scif_info.rmalock);
460 schedule_work(&scif_info.misc_work);
461 }
462
463 static inline void __scif_rma_destroy_tcw_helper(struct scif_window *window)
464 {
465 list_del_init(&window->list);
466 scif_queue_for_cleanup(window, &scif_info.rma_tc);
467 }
468
469 static inline bool scif_is_iommu_enabled(void)
470 {
471 #ifdef CONFIG_INTEL_IOMMU
472 return intel_iommu_enabled;
473 #else
474 return false;
475 #endif
476 }
477 #endif /* SCIF_RMA_H */