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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/dma_remapping.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*/
99struct 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 */
124struct 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 */
136struct 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 */
147enum 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 */
168struct 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 */
186struct 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 */
202struct scif_status {
203 dma_addr_t src_dma_addr;
204 u64 val;
205 struct scif_endpt *ep;
206};
207
208/*
209 * struct scif_window - Registration Window for Self and Remote
210 *
211 * @nr_pages: Number of pages which is defined as a s64 instead of an int
212 * to avoid sign extension with buffers >= 2GB
213 * @nr_contig_chunks: Number of contiguous physical chunks
214 * @prot: read/write protections
215 * @ref_count: reference count in terms of number of pages
216 * @magic: Cookie to detect corruption
217 * @offset: registered offset
218 * @va_for_temp: va address that this window represents
219 * @dma_mark: Used to determine if all DMAs against the window are done
220 * @ep: Pointer to EP. Useful for passing EP around with messages to
221 avoid expensive list traversals.
222 * @list: link to list of windows for the endpoint
223 * @type: self or peer window
224 * @peer_window: Pointer to peer window. Useful for sending messages to peer
225 * without requiring an extra list traversal
226 * @unreg_state: unregistration state
227 * @offset_freed: True if the offset has been freed
228 * @temp: True for temporary windows created via scif_vreadfrom/scif_vwriteto
229 * @mm: memory descriptor for the task_struct which initiated the RMA
230 * @st: scatter gather table for DMA mappings with IOMMU enabled
231 * @pinned_pages: The set of pinned_pages backing this window
232 * @alloc_handle: Handle for sending ALLOC_REQ
233 * @regwq: Wait Queue for an registration (N)ACK
234 * @reg_state: Registration state
235 * @unregwq: Wait Queue for an unregistration (N)ACK
236 * @dma_addr_lookup: Lookup for physical addresses used for DMA
237 * @nr_lookup: Number of entries in lookup
238 * @mapped_offset: Offset used to map the window by the peer
239 * @dma_addr: Array of physical addresses used for Mgmt node & MIC initiated DMA
240 * @num_pages: Array specifying number of pages for each physical address
241 */
242struct scif_window {
243 s64 nr_pages;
244 int nr_contig_chunks;
245 int prot;
246 int ref_count;
247 u64 magic;
248 s64 offset;
249 unsigned long va_for_temp;
250 int dma_mark;
251 u64 ep;
252 struct list_head list;
253 enum scif_window_type type;
254 u64 peer_window;
255 enum scif_msg_state unreg_state;
256 bool offset_freed;
257 bool temp;
258 struct mm_struct *mm;
259 struct sg_table *st;
260 union {
261 struct {
262 struct scif_pinned_pages *pinned_pages;
263 struct scif_allocmsg alloc_handle;
264 wait_queue_head_t regwq;
265 enum scif_msg_state reg_state;
266 wait_queue_head_t unregwq;
267 };
268 struct {
269 struct scif_rma_lookup dma_addr_lookup;
270 struct scif_rma_lookup num_pages_lookup;
271 int nr_lookup;
272 dma_addr_t mapped_offset;
273 };
274 };
275 dma_addr_t *dma_addr;
276 u64 *num_pages;
277} __packed;
278
279/*
280 * scif_mmu_notif - SCIF mmu notifier information
281 *
282 * @mmu_notifier ep_mmu_notifier: MMU notifier operations
283 * @tc_reg_list: List of temp registration windows for self
284 * @mm: memory descriptor for the task_struct which initiated the RMA
285 * @ep: SCIF endpoint
286 * @list: link to list of MMU notifier information
287 */
288struct scif_mmu_notif {
289#ifdef CONFIG_MMU_NOTIFIER
290 struct mmu_notifier ep_mmu_notifier;
291#endif
292 struct list_head tc_reg_list;
293 struct mm_struct *mm;
294 struct scif_endpt *ep;
295 struct list_head list;
296};
297
298enum scif_rma_dir {
299 SCIF_LOCAL_TO_REMOTE,
300 SCIF_REMOTE_TO_LOCAL
301};
302
303extern struct kmem_cache *unaligned_cache;
304/* Initialize RMA for this EP */
305void scif_rma_ep_init(struct scif_endpt *ep);
306/* Check if epd can be uninitialized */
307int scif_rma_ep_can_uninit(struct scif_endpt *ep);
308/* Obtain a new offset. Callee must grab RMA lock */
309int scif_get_window_offset(struct scif_endpt *ep, int flags,
310 s64 offset, int nr_pages, s64 *out_offset);
311/* Free offset. Callee must grab RMA lock */
312void scif_free_window_offset(struct scif_endpt *ep,
313 struct scif_window *window, s64 offset);
314/* Create self registration window */
315struct scif_window *scif_create_window(struct scif_endpt *ep, int nr_pages,
316 s64 offset, bool temp);
317/* Destroy self registration window.*/
318int scif_destroy_window(struct scif_endpt *ep, struct scif_window *window);
319void scif_unmap_window(struct scif_dev *remote_dev, struct scif_window *window);
320/* Map pages of self window to Aperture/PCI */
321int scif_map_window(struct scif_dev *remote_dev,
322 struct scif_window *window);
323/* Unregister a self window */
324int scif_unregister_window(struct scif_window *window);
325/* Destroy remote registration window */
326void
327scif_destroy_remote_window(struct scif_window *window);
328/* remove valid remote memory mappings from process address space */
329void scif_zap_mmaps(int node);
330/* Query if any applications have remote memory mappings */
331bool scif_rma_do_apps_have_mmaps(int node);
332/* Cleanup remote registration lists for zombie endpoints */
333void scif_cleanup_rma_for_zombies(int node);
334/* Reserve a DMA channel for a particular endpoint */
335int scif_reserve_dma_chan(struct scif_endpt *ep);
336/* Setup a DMA mark for an endpoint */
337int _scif_fence_mark(scif_epd_t epd, int *mark);
338int scif_prog_signal(scif_epd_t epd, off_t offset, u64 val,
339 enum scif_window_type type);
340void scif_alloc_req(struct scif_dev *scifdev, struct scifmsg *msg);
341void scif_alloc_gnt_rej(struct scif_dev *scifdev, struct scifmsg *msg);
342void scif_free_virt(struct scif_dev *scifdev, struct scifmsg *msg);
343void scif_recv_reg(struct scif_dev *scifdev, struct scifmsg *msg);
344void scif_recv_unreg(struct scif_dev *scifdev, struct scifmsg *msg);
345void scif_recv_reg_ack(struct scif_dev *scifdev, struct scifmsg *msg);
346void scif_recv_reg_nack(struct scif_dev *scifdev, struct scifmsg *msg);
347void scif_recv_unreg_ack(struct scif_dev *scifdev, struct scifmsg *msg);
348void scif_recv_unreg_nack(struct scif_dev *scifdev, struct scifmsg *msg);
349void scif_recv_munmap(struct scif_dev *scifdev, struct scifmsg *msg);
350void scif_recv_mark(struct scif_dev *scifdev, struct scifmsg *msg);
351void scif_recv_mark_resp(struct scif_dev *scifdev, struct scifmsg *msg);
352void scif_recv_wait(struct scif_dev *scifdev, struct scifmsg *msg);
353void scif_recv_wait_resp(struct scif_dev *scifdev, struct scifmsg *msg);
354void scif_recv_sig_local(struct scif_dev *scifdev, struct scifmsg *msg);
355void scif_recv_sig_remote(struct scif_dev *scifdev, struct scifmsg *msg);
356void scif_recv_sig_resp(struct scif_dev *scifdev, struct scifmsg *msg);
357void scif_mmu_notif_handler(struct work_struct *work);
358void scif_rma_handle_remote_fences(void);
359void scif_rma_destroy_windows(void);
360void scif_rma_destroy_tcw_invalid(void);
361int scif_drain_dma_intr(struct scif_hw_dev *sdev, struct dma_chan *chan);
362
363struct scif_window_iter {
364 s64 offset;
365 int index;
366};
367
368static inline void
369scif_init_window_iter(struct scif_window *window, struct scif_window_iter *iter)
370{
371 iter->offset = window->offset;
372 iter->index = 0;
373}
374
375dma_addr_t scif_off_to_dma_addr(struct scif_window *window, s64 off,
376 size_t *nr_bytes,
377 struct scif_window_iter *iter);
378static inline
379dma_addr_t __scif_off_to_dma_addr(struct scif_window *window, s64 off)
380{
381 return scif_off_to_dma_addr(window, off, NULL, NULL);
382}
383
384static inline bool scif_unaligned(off_t src_offset, off_t dst_offset)
385{
386 src_offset = src_offset & (L1_CACHE_BYTES - 1);
387 dst_offset = dst_offset & (L1_CACHE_BYTES - 1);
388 return !(src_offset == dst_offset);
389}
390
391/*
392 * scif_zalloc:
393 * @size: Size of the allocation request.
394 *
395 * Helper API which attempts to allocate zeroed pages via
396 * __get_free_pages(..) first and then falls back on
397 * vzalloc(..) if that fails.
398 */
399static inline void *scif_zalloc(size_t size)
400{
401 void *ret = NULL;
402 size_t align = ALIGN(size, PAGE_SIZE);
403
404 if (align && get_order(align) < MAX_ORDER)
405 ret = (void *)__get_free_pages(GFP_KERNEL | __GFP_ZERO,
406 get_order(align));
407 return ret ? ret : vzalloc(align);
408}
409
410/*
411 * scif_free:
412 * @addr: Address to be freed.
413 * @size: Size of the allocation.
414 * Helper API which frees memory allocated via scif_zalloc().
415 */
416static inline void scif_free(void *addr, size_t size)
417{
418 size_t align = ALIGN(size, PAGE_SIZE);
419
420 if (is_vmalloc_addr(addr))
421 vfree(addr);
422 else
423 free_pages((unsigned long)addr, get_order(align));
424}
425
426static inline void scif_get_window(struct scif_window *window, int nr_pages)
427{
428 window->ref_count += nr_pages;
429}
430
431static inline void scif_put_window(struct scif_window *window, int nr_pages)
432{
433 window->ref_count -= nr_pages;
434}
435
436static inline void scif_set_window_ref(struct scif_window *window, int nr_pages)
437{
438 window->ref_count = nr_pages;
439}
440
441static inline void
442scif_queue_for_cleanup(struct scif_window *window, struct list_head *list)
443{
444 spin_lock(&scif_info.rmalock);
445 list_add_tail(&window->list, list);
446 spin_unlock(&scif_info.rmalock);
447 schedule_work(&scif_info.misc_work);
448}
449
450static inline void __scif_rma_destroy_tcw_helper(struct scif_window *window)
451{
452 list_del_init(&window->list);
453 scif_queue_for_cleanup(window, &scif_info.rma_tc);
454}
455
456static inline bool scif_is_iommu_enabled(void)
457{
458#ifdef CONFIG_INTEL_IOMMU
459 return intel_iommu_enabled;
460#else
461 return false;
462#endif
463}
464#endif /* SCIF_RMA_H */