xref: /freebsd/sys/contrib/vchiq/interface/vchiq_arm/vchiq_2835_arm.c (revision 97e24b41d2d224cfb4043f1ae84fc23d9033d0a1)
1 /**
2  * Copyright (c) 2010-2012 Broadcom. All rights reserved.
3  *
4  * Redistribution and use in source and binary forms, with or without
5  * modification, are permitted provided that the following conditions
6  * are met:
7  * 1. Redistributions of source code must retain the above copyright
8  *    notice, this list of conditions, and the following disclaimer,
9  *    without modification.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  * 3. The names of the above-listed copyright holders may not be used
14  *    to endorse or promote products derived from this software without
15  *    specific prior written permission.
16  *
17  * ALTERNATIVELY, this software may be distributed under the terms of the
18  * GNU General Public License ("GPL") version 2, as published by the Free
19  * Software Foundation.
20  *
21  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
22  * IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
23  * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
24  * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
25  * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
26  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
27  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
28  * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
29  * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
30  * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
31  * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
32  */
33 
34 #include <interface/compat/vchi_bsd.h>
35 
36 #include <sys/malloc.h>
37 #include <sys/rwlock.h>
38 
39 #include <vm/vm.h>
40 #include <vm/pmap.h>
41 #include <vm/vm_extern.h>
42 #include <vm/vm_kern.h>
43 #include <vm/vm_map.h>
44 #include <vm/vm_object.h>
45 #include <vm/vm_page.h>
46 #include <vm/vm_pager.h>
47 #include <vm/vm_param.h>
48 
49 #include <machine/bus.h>
50 #include <machine/cpu.h>
51 #include <arm/broadcom/bcm2835/bcm2835_mbox.h>
52 #include <arm/broadcom/bcm2835/bcm2835_vcbus.h>
53 
54 MALLOC_DEFINE(M_VCPAGELIST, "vcpagelist", "VideoCore pagelist memory");
55 
56 #define TOTAL_SLOTS (VCHIQ_SLOT_ZERO_SLOTS + 2 * 32)
57 
58 #define VCHIQ_DOORBELL_IRQ IRQ_ARM_DOORBELL_0
59 #define VCHIQ_ARM_ADDRESS(x) ((void *)PHYS_TO_VCBUS(pmap_kextract((vm_offset_t)(x))))
60 
61 #include "vchiq_arm.h"
62 #include "vchiq_2835.h"
63 #include "vchiq_connected.h"
64 #include "vchiq_killable.h"
65 
66 #define MAX_FRAGMENTS (VCHIQ_NUM_CURRENT_BULKS * 2)
67 
68 /*
69  *  XXXMDC
70  * Do this less ad-hoc-y -- e.g.
71  * https://github.com/raspberrypi/linux/commit/c683db8860a80562a2bb5b451d77b3e471d24f36
72  */
73 #if defined(__aarch64__)
74 int g_cache_line_size = 64;
75 #else
76 int g_cache_line_size = 32;
77 #endif
78 static int g_fragment_size;
79 
80 unsigned int g_long_bulk_space = 0;
81 #define VM_PAGE_TO_VC_BULK_PAGE(x) (\
82 	g_long_bulk_space ? VM_PAGE_TO_PHYS(x)\
83 		 : PHYS_TO_VCBUS(VM_PAGE_TO_PHYS(x))\
84 )
85 
86 typedef struct vchiq_2835_state_struct {
87    int inited;
88    VCHIQ_ARM_STATE_T arm_state;
89 } VCHIQ_2835_ARM_STATE_T;
90 
91 static char *g_slot_mem;
92 static int g_slot_mem_size;
93 vm_paddr_t g_slot_phys;
94 /* BSD DMA */
95 bus_dma_tag_t bcm_slots_dma_tag;
96 bus_dmamap_t bcm_slots_dma_map;
97 
98 static char *g_fragments_base;
99 static char *g_free_fragments;
100 struct semaphore g_free_fragments_sema;
101 
102 static DEFINE_SEMAPHORE(g_free_fragments_mutex);
103 
104 typedef struct bulkinfo_struct {
105 	PAGELIST_T	*pagelist;
106 	bus_dma_tag_t	pagelist_dma_tag;
107 	bus_dmamap_t	pagelist_dma_map;
108 	void		*buf;
109 	size_t		size;
110 } BULKINFO_T;
111 
112 static int
113 create_pagelist(char __user *buf, size_t count, unsigned short type,
114                 struct proc *p, BULKINFO_T *bi);
115 
116 static void
117 free_pagelist(BULKINFO_T *bi, int actual);
118 
119 static void
vchiq_dmamap_cb(void * arg,bus_dma_segment_t * segs,int nseg,int err)120 vchiq_dmamap_cb(void *arg, bus_dma_segment_t *segs, int nseg, int err)
121 {
122 	bus_addr_t *addr;
123 
124 	if (err)
125 		return;
126 
127 	addr = (bus_addr_t*)arg;
128 	*addr = PHYS_TO_VCBUS(segs[0].ds_addr);
129 }
130 
131 #if defined(__aarch64__) /* See comment in free_pagelist */
132 static int
invalidate_cachelines_in_range_of_ppage(vm_page_t p,size_t offset,size_t count)133 invalidate_cachelines_in_range_of_ppage(
134 	vm_page_t p,
135 	size_t offset,
136 	size_t count
137 )
138 {
139 	if(offset + count > PAGE_SIZE){ return EINVAL; }
140         uint8_t *dst = pmap_quick_enter_page(p);
141         if (!dst){
142                 return ENOMEM;
143 	}
144 	cpu_dcache_inv_range(dst + offset, count);
145 	pmap_quick_remove_page(dst);
146 	return 0;
147 }
148 
149 /* XXXMDC bulk instead of loading and invalidating single pages? */
150 static void
invalidate_cachelines_in_range_of_ppage_seq(vm_page_t * p,size_t start,size_t count)151 invalidate_cachelines_in_range_of_ppage_seq(vm_page_t *p, size_t start,
152     size_t count)
153 {
154 	if (start >= PAGE_SIZE)
155 		goto invalid_input;
156 
157 #define _NEXT_AT(x,_m) (((x)+((_m)-1)) & ~((_m)-1))   /* for power of two m */
158 	size_t offset = _NEXT_AT(start,g_cache_line_size);
159 #undef _NEXT_AT
160 	count = (offset < start + count) ? count - (offset - start) : 0;
161 	offset = offset & (PAGE_SIZE - 1);
162 	for (size_t done = 0; count > done;
163 	    p++, done += PAGE_SIZE - offset, offset = 0) {
164 		size_t in_page = PAGE_SIZE - offset;
165 		size_t todo = (count-done > in_page) ? in_page : count-done;
166 		int e = invalidate_cachelines_in_range_of_ppage(*p, offset, todo);
167 		if (e != 0)
168 			goto problem_in_loop;
169 	}
170 	return;
171 
172 problem_in_loop:
173 invalid_input:
174 	WARN_ON(1);
175 	return;
176 }
177 #endif
178 
179 static int
copyout_page(vm_page_t p,size_t offset,void * kaddr,size_t size)180 copyout_page(vm_page_t p, size_t offset, void *kaddr, size_t size)
181 {
182         uint8_t *dst;
183 
184         dst = pmap_quick_enter_page(p);
185         if (!dst)
186                 return ENOMEM;
187 
188         memcpy(dst + offset, kaddr, size);
189 
190         pmap_quick_remove_page(dst);
191 
192         return 0;
193 }
194 
195 int __init
vchiq_platform_init(VCHIQ_STATE_T * state)196 vchiq_platform_init(VCHIQ_STATE_T *state)
197 {
198 	VCHIQ_SLOT_ZERO_T *vchiq_slot_zero;
199 	int frag_mem_size;
200 	int err;
201 	int i;
202 
203 	/* Allocate space for the channels in coherent memory */
204 	g_slot_mem_size = PAGE_ALIGN(TOTAL_SLOTS * VCHIQ_SLOT_SIZE);
205 	g_fragment_size = 2*g_cache_line_size;
206 	frag_mem_size = PAGE_ALIGN(g_fragment_size * MAX_FRAGMENTS);
207 
208 	err = bus_dma_tag_create(
209 	    NULL,
210 	    PAGE_SIZE, 0,	       /* alignment, boundary */
211 	    BUS_SPACE_MAXADDR_32BIT,    /* lowaddr */
212 	    BUS_SPACE_MAXADDR,	  /* highaddr */
213 	    NULL, NULL,		 /* filter, filterarg */
214 	    g_slot_mem_size + frag_mem_size, 1,		/* maxsize, nsegments */
215 	    g_slot_mem_size + frag_mem_size, 0,		/* maxsegsize, flags */
216 	    NULL, NULL,		 /* lockfunc, lockarg */
217 	    &bcm_slots_dma_tag);
218 
219 	err = bus_dmamem_alloc(bcm_slots_dma_tag, (void **)&g_slot_mem,
220 	    BUS_DMA_COHERENT | BUS_DMA_WAITOK, &bcm_slots_dma_map);
221 	if (err) {
222 		vchiq_log_error(vchiq_core_log_level, "Unable to allocate channel memory");
223 		err = -ENOMEM;
224 		goto failed_alloc;
225 	}
226 
227 	err = bus_dmamap_load(bcm_slots_dma_tag, bcm_slots_dma_map, g_slot_mem,
228 	    g_slot_mem_size + frag_mem_size, vchiq_dmamap_cb,
229 	    &g_slot_phys, 0);
230 
231 	if (err) {
232 		vchiq_log_error(vchiq_core_log_level, "cannot load DMA map");
233 		err = -ENOMEM;
234 		goto failed_load;
235 	}
236 
237 	WARN_ON(((size_t)g_slot_mem & (PAGE_SIZE - 1)) != 0);
238 
239 	vchiq_slot_zero = vchiq_init_slots(g_slot_mem, g_slot_mem_size);
240 	if (!vchiq_slot_zero) {
241 		err = -EINVAL;
242 		goto failed_init_slots;
243 	}
244 
245 	vchiq_slot_zero->platform_data[VCHIQ_PLATFORM_FRAGMENTS_OFFSET_IDX] =
246 		(int)g_slot_phys + g_slot_mem_size;
247 	vchiq_slot_zero->platform_data[VCHIQ_PLATFORM_FRAGMENTS_COUNT_IDX] =
248 		MAX_FRAGMENTS;
249 
250 	g_fragments_base = (char *)(g_slot_mem + g_slot_mem_size);
251 	g_slot_mem_size += frag_mem_size;
252 
253 	g_free_fragments = g_fragments_base;
254 	for (i = 0; i < (MAX_FRAGMENTS - 1); i++) {
255 		*(char **)&g_fragments_base[i*g_fragment_size] =
256 			&g_fragments_base[(i + 1)*g_fragment_size];
257 	}
258 	*(char **)&g_fragments_base[i*g_fragment_size] = NULL;
259 	_sema_init(&g_free_fragments_sema, MAX_FRAGMENTS);
260 
261 	if (vchiq_init_state(state, vchiq_slot_zero, 0/*slave*/) !=
262 		VCHIQ_SUCCESS) {
263 		err = -EINVAL;
264 		goto failed_vchiq_init;
265 	}
266 
267 	bcm_mbox_write(BCM2835_MBOX_CHAN_VCHIQ, (unsigned int)g_slot_phys);
268 
269 	vchiq_log_info(vchiq_arm_log_level,
270 		"vchiq_init - done (slots %zx, phys %zx)",
271 		(size_t)vchiq_slot_zero, g_slot_phys);
272 
273    vchiq_call_connected_callbacks();
274 
275    return 0;
276 
277 failed_vchiq_init:
278 failed_init_slots:
279 	bus_dmamap_unload(bcm_slots_dma_tag, bcm_slots_dma_map);
280 failed_load:
281 	bus_dmamem_free(bcm_slots_dma_tag, g_slot_mem, bcm_slots_dma_map);
282 failed_alloc:
283 	bus_dma_tag_destroy(bcm_slots_dma_tag);
284 
285    return err;
286 }
287 
288 void __exit
vchiq_platform_exit(VCHIQ_STATE_T * state)289 vchiq_platform_exit(VCHIQ_STATE_T *state)
290 {
291 
292 	bus_dmamap_unload(bcm_slots_dma_tag, bcm_slots_dma_map);
293 	bus_dmamem_free(bcm_slots_dma_tag, g_slot_mem, bcm_slots_dma_map);
294 	bus_dma_tag_destroy(bcm_slots_dma_tag);
295 }
296 
297 VCHIQ_STATUS_T
vchiq_platform_init_state(VCHIQ_STATE_T * state)298 vchiq_platform_init_state(VCHIQ_STATE_T *state)
299 {
300    VCHIQ_STATUS_T status = VCHIQ_SUCCESS;
301    state->platform_state = kzalloc(sizeof(VCHIQ_2835_ARM_STATE_T), GFP_KERNEL);
302    ((VCHIQ_2835_ARM_STATE_T*)state->platform_state)->inited = 1;
303    status = vchiq_arm_init_state(state, &((VCHIQ_2835_ARM_STATE_T*)state->platform_state)->arm_state);
304    if(status != VCHIQ_SUCCESS)
305    {
306       ((VCHIQ_2835_ARM_STATE_T*)state->platform_state)->inited = 0;
307    }
308    return status;
309 }
310 
311 VCHIQ_ARM_STATE_T*
vchiq_platform_get_arm_state(VCHIQ_STATE_T * state)312 vchiq_platform_get_arm_state(VCHIQ_STATE_T *state)
313 {
314    if(!((VCHIQ_2835_ARM_STATE_T*)state->platform_state)->inited)
315    {
316       BUG();
317    }
318    return &((VCHIQ_2835_ARM_STATE_T*)state->platform_state)->arm_state;
319 }
320 
321 VCHIQ_STATUS_T
vchiq_prepare_bulk_data(VCHIQ_BULK_T * bulk,VCHI_MEM_HANDLE_T memhandle,void * offset,int size,int dir)322 vchiq_prepare_bulk_data(VCHIQ_BULK_T *bulk, VCHI_MEM_HANDLE_T memhandle,
323 	void *offset, int size, int dir)
324 {
325 	BULKINFO_T *bi;
326 	int ret;
327 
328 	WARN_ON(memhandle != VCHI_MEM_HANDLE_INVALID);
329 	bi = malloc(sizeof(*bi), M_VCPAGELIST, M_WAITOK | M_ZERO);
330 
331 	ret = create_pagelist((char __user *)offset, size,
332 			(dir == VCHIQ_BULK_RECEIVE)
333 			? PAGELIST_READ
334 			: PAGELIST_WRITE,
335 			current,
336 			bi);
337 	if (ret != 0)
338 		return VCHIQ_ERROR;
339 
340 	bulk->handle = memhandle;
341 	bulk->data = VCHIQ_ARM_ADDRESS(bi->pagelist);
342 
343 	/* Store the pagelist address in remote_data, which isn't used by the
344 	   slave. */
345 	bulk->remote_data = bi;
346 
347 	return VCHIQ_SUCCESS;
348 }
349 
350 void
vchiq_complete_bulk(VCHIQ_BULK_T * bulk)351 vchiq_complete_bulk(VCHIQ_BULK_T *bulk)
352 {
353 	if (bulk && bulk->remote_data && bulk->actual)
354 		free_pagelist((BULKINFO_T *)bulk->remote_data, bulk->actual);
355 }
356 
357 void
vchiq_transfer_bulk(VCHIQ_BULK_T * bulk)358 vchiq_transfer_bulk(VCHIQ_BULK_T *bulk)
359 {
360 	/*
361 	 * This should only be called on the master (VideoCore) side, but
362 	 * provide an implementation to avoid the need for ifdefery.
363 	 */
364 	BUG();
365 }
366 
367 void
vchiq_dump_platform_state(void * dump_context)368 vchiq_dump_platform_state(void *dump_context)
369 {
370 	char buf[80];
371 	int len;
372 	len = snprintf(buf, sizeof(buf),
373 		"  Platform: 2835 (VC master)");
374 	vchiq_dump(dump_context, buf, len + 1);
375 }
376 
377 VCHIQ_STATUS_T
vchiq_platform_suspend(VCHIQ_STATE_T * state)378 vchiq_platform_suspend(VCHIQ_STATE_T *state)
379 {
380    return VCHIQ_ERROR;
381 }
382 
383 VCHIQ_STATUS_T
vchiq_platform_resume(VCHIQ_STATE_T * state)384 vchiq_platform_resume(VCHIQ_STATE_T *state)
385 {
386    return VCHIQ_SUCCESS;
387 }
388 
389 void
vchiq_platform_paused(VCHIQ_STATE_T * state)390 vchiq_platform_paused(VCHIQ_STATE_T *state)
391 {
392 }
393 
394 void
vchiq_platform_resumed(VCHIQ_STATE_T * state)395 vchiq_platform_resumed(VCHIQ_STATE_T *state)
396 {
397 }
398 
399 int
vchiq_platform_videocore_wanted(VCHIQ_STATE_T * state)400 vchiq_platform_videocore_wanted(VCHIQ_STATE_T* state)
401 {
402    return 1; // autosuspend not supported - videocore always wanted
403 }
404 
405 int
vchiq_platform_use_suspend_timer(void)406 vchiq_platform_use_suspend_timer(void)
407 {
408    return 0;
409 }
410 void
vchiq_dump_platform_use_state(VCHIQ_STATE_T * state)411 vchiq_dump_platform_use_state(VCHIQ_STATE_T *state)
412 {
413 	vchiq_log_info(vchiq_arm_log_level, "Suspend timer not in use");
414 }
415 void
vchiq_platform_handle_timeout(VCHIQ_STATE_T * state)416 vchiq_platform_handle_timeout(VCHIQ_STATE_T *state)
417 {
418 	(void)state;
419 }
420 /*
421  * Local functions
422  */
423 
424 static void
pagelist_page_free(vm_page_t pp)425 pagelist_page_free(vm_page_t pp)
426 {
427 	vm_page_unwire(pp, PQ_INACTIVE);
428 }
429 
430 /* There is a potential problem with partial cache lines (pages?)
431 ** at the ends of the block when reading. If the CPU accessed anything in
432 ** the same line (page?) then it may have pulled old data into the cache,
433 ** obscuring the new data underneath. We can solve this by transferring the
434 ** partial cache lines separately, and allowing the ARM to copy into the
435 ** cached area.
436 
437 ** N.B. This implementation plays slightly fast and loose with the Linux
438 ** driver programming rules, e.g. its use of __virt_to_bus instead of
439 ** dma_map_single, but it isn't a multi-platform driver and it benefits
440 ** from increased speed as a result.
441 */
442 
443 
444 static int
create_pagelist(char __user * buf,size_t count,unsigned short type,struct proc * p,BULKINFO_T * bi)445 create_pagelist(char __user *buf, size_t count, unsigned short type,
446 	struct proc *p, BULKINFO_T *bi)
447 {
448 	PAGELIST_T *pagelist;
449 	vm_page_t* pages;
450 	uint32_t *addrs;
451 	unsigned int num_pages, i;
452 	vm_offset_t offset;
453 	int pagelist_size;
454 	char *addr, *base_addr, *next_addr;
455 	int run, addridx, actual_pages;
456 	int err;
457 	vm_paddr_t pagelist_phys;
458 	vm_paddr_t pa;
459 
460 	offset = (vm_offset_t)buf & (PAGE_SIZE - 1);
461 	num_pages = (count + offset + PAGE_SIZE - 1) / PAGE_SIZE;
462 
463 	bi->pagelist = NULL;
464 	bi->buf = buf;
465 	bi->size = count;
466 
467 	/* Allocate enough storage to hold the page pointers and the page
468 	** list
469 	*/
470 	pagelist_size = sizeof(PAGELIST_T) +
471 		(num_pages * sizeof(unsigned long)) +
472 		(num_pages * sizeof(pages[0]));
473 
474 	err = bus_dma_tag_create(
475 	    NULL,
476 	    PAGE_SIZE, 0,	       /* alignment, boundary */
477 	    BUS_SPACE_MAXADDR_32BIT,    /* lowaddr */
478 	    BUS_SPACE_MAXADDR,	  /* highaddr */
479 	    NULL, NULL,		 /* filter, filterarg */
480 	    pagelist_size, 1,		/* maxsize, nsegments */
481 	    pagelist_size, 0,		/* maxsegsize, flags */
482 	    NULL, NULL,		 /* lockfunc, lockarg */
483 	    &bi->pagelist_dma_tag);
484 
485 	err = bus_dmamem_alloc(bi->pagelist_dma_tag, (void **)&pagelist,
486 	    BUS_DMA_COHERENT | BUS_DMA_WAITOK, &bi->pagelist_dma_map);
487 	if (err || !pagelist) {
488 		vchiq_log_error(vchiq_core_log_level, "Unable to allocate pagelist memory");
489 		err = -ENOMEM;
490 		goto failed_alloc;
491 	}
492 
493 	err = bus_dmamap_load(bi->pagelist_dma_tag, bi->pagelist_dma_map, pagelist,
494 	    pagelist_size, vchiq_dmamap_cb,
495 	    &pagelist_phys, 0);
496 
497 	if (err) {
498 		vchiq_log_error(vchiq_core_log_level, "cannot load DMA map for pagelist memory");
499 		err = -ENOMEM;
500 		bi->pagelist = pagelist;
501 		goto failed_load;
502 	}
503 
504 	vchiq_log_trace(vchiq_arm_log_level,
505 		"create_pagelist - %zx (%zu bytes @%p)", (size_t)pagelist, count, buf);
506 
507 	addrs = pagelist->addrs;
508 	pages = (vm_page_t*)(addrs + num_pages);
509 
510 	actual_pages = vm_fault_quick_hold_pages(&p->p_vmspace->vm_map,
511 	    (vm_offset_t)buf, count,
512 	    (type == PAGELIST_READ ? VM_PROT_WRITE : 0 ) | VM_PROT_READ, pages, num_pages);
513 
514 	if (actual_pages != num_pages) {
515 		if (actual_pages > 0)
516 			vm_page_unhold_pages(pages, actual_pages);
517 		err = -ENOMEM;
518 		bi->pagelist = pagelist;
519 		goto failed_hold;
520 	}
521 
522 	pagelist->length = count;
523 	pagelist->type = type;
524 	pagelist->offset = offset;
525 
526 	/* Group the pages into runs of contiguous pages */
527 
528 	size_t run_ceil = g_long_bulk_space ? 0x100 : PAGE_SIZE;
529 	unsigned int pg_addr_rshift = g_long_bulk_space ? 4 : 0;
530 	base_addr = (void *) VM_PAGE_TO_VC_BULK_PAGE(pages[0]);
531 	next_addr = base_addr + PAGE_SIZE;
532 	addridx = 0;
533 	run = 0;
534 #define _PG_BLOCK(base,run) \
535 		((((size_t) (base)) >> pg_addr_rshift) & ~(run_ceil-1)) + (run)
536 	for (i = 1; i < num_pages; i++) {
537 		addr = (void *)VM_PAGE_TO_VC_BULK_PAGE(pages[i]);
538 		if ((addr == next_addr) && (run < run_ceil - 1)) {
539 			next_addr += PAGE_SIZE;
540 			run++;
541 		} else {
542 			addrs[addridx++] = (uint32_t) _PG_BLOCK(base_addr,run);
543 			base_addr = addr;
544 			next_addr = addr + PAGE_SIZE;
545 			run = 0;
546 		}
547 	}
548 	addrs[addridx++] = _PG_BLOCK(base_addr, run);
549 #undef _PG_BLOCK
550 
551 	/* Partial cache lines (fragments) require special measures */
552 	if ((type == PAGELIST_READ) &&
553 		((pagelist->offset & (g_cache_line_size - 1)) ||
554 		((pagelist->offset + pagelist->length) &
555 		(g_cache_line_size - 1)))) {
556 		char *fragments;
557 
558 		if (down_interruptible(&g_free_fragments_sema) != 0) {
559       			free(pagelist, M_VCPAGELIST);
560 			return -EINTR;
561 		}
562 
563 		WARN_ON(g_free_fragments == NULL);
564 
565 		down(&g_free_fragments_mutex);
566 		fragments = g_free_fragments;
567 		WARN_ON(fragments == NULL);
568 		g_free_fragments = *(char **) g_free_fragments;
569 		up(&g_free_fragments_mutex);
570 		pagelist->type = PAGELIST_READ_WITH_FRAGMENTS
571 		     + (fragments - g_fragments_base)/g_fragment_size;
572 #if defined(__aarch64__)
573 		 bus_dmamap_sync(bcm_slots_dma_tag, bcm_slots_dma_map,
574 		     BUS_DMASYNC_PREREAD);
575 #endif
576 	}
577 
578 #if defined(__aarch64__)
579 	if(type == PAGELIST_READ) {
580 		cpu_dcache_wbinv_range(buf, count);
581 	} else {
582 		cpu_dcache_wb_range(buf, count);
583 	}
584 	dsb(sy);
585 #else
586 	pa = pmap_extract(PCPU_GET(curpmap), (vm_offset_t)buf);
587 	dcache_wbinv_poc((vm_offset_t)buf, pa, count);
588 #endif
589 
590 	bus_dmamap_sync(bi->pagelist_dma_tag, bi->pagelist_dma_map,
591 	    BUS_DMASYNC_PREWRITE);
592 
593 	bi->pagelist = pagelist;
594 
595 	return 0;
596 
597 failed_hold:
598 	bus_dmamap_unload(bi->pagelist_dma_tag,bi->pagelist_dma_map);
599 failed_load:
600 	bus_dmamem_free(bi->pagelist_dma_tag, bi->pagelist, bi->pagelist_dma_map);
601 failed_alloc:
602 	bus_dma_tag_destroy(bi->pagelist_dma_tag);
603 
604 	return err;
605 }
606 
607 static void
free_pagelist(BULKINFO_T * bi,int actual)608 free_pagelist(BULKINFO_T *bi, int actual)
609 {
610 	vm_page_t*pages;
611 	unsigned int num_pages, i;
612 	PAGELIST_T *pagelist;
613 
614 	pagelist = bi->pagelist;
615 
616 	vchiq_log_trace(vchiq_arm_log_level,
617 	    "free_pagelist - %zx, %d (%lu bytes @%p)",
618 	    (size_t)pagelist, (int)actual, (unsigned long)pagelist->length,
619 	    bi->buf);
620 
621 	num_pages =
622 		(pagelist->length + pagelist->offset + PAGE_SIZE - 1) /
623 		PAGE_SIZE;
624 
625 	pages = (vm_page_t*)(pagelist->addrs + num_pages);
626 
627 #if defined(__aarch64__)
628 	/*
629          * On arm64, even if the user keeps their end of the bargain
630 	 * -- do NOT touch the buffers sent to VC -- but reads around the
631 	 * pagelist after the invalidation above, the arm might preemptively
632 	 * load (and validate) cache lines for areas inside the page list,
633 	 * so we must invalidate them again.
634 	 *
635 	 * The functional test does it and without this it doesn't pass.
636 	 *
637 	 * XXXMDC might it be enough to invalidate a couple of pages at
638 	 * the ends of the page list?
639 	 */
640 	if(pagelist->type >= PAGELIST_READ && actual > 0)
641 		invalidate_cachelines_in_range_of_ppage_seq(pages,
642 		    pagelist->offset, actual);
643 #endif
644 
645 	/* Deal with any partial cache lines (fragments) */
646 	if (pagelist->type >= PAGELIST_READ_WITH_FRAGMENTS) {
647 		char *fragments = g_fragments_base +
648 			(pagelist->type - PAGELIST_READ_WITH_FRAGMENTS)*g_fragment_size;
649 		int head_bytes, tail_bytes;
650 		head_bytes = (g_cache_line_size - pagelist->offset) &
651 			(g_cache_line_size - 1);
652 		tail_bytes = (pagelist->offset + actual) &
653 			(g_cache_line_size - 1);
654 
655 		if ((actual >= 0) && (head_bytes != 0)) {
656 			if (head_bytes > actual)
657 				head_bytes = actual;
658 
659 			copyout_page(pages[0],
660 				pagelist->offset,
661 				fragments,
662 				head_bytes);
663 		}
664 
665 		if ((actual >= 0) && (head_bytes < actual) &&
666 			(tail_bytes != 0)) {
667 
668 			copyout_page(pages[num_pages-1],
669 				(((vm_offset_t)bi->buf + actual) % PAGE_SIZE) - tail_bytes,
670 				fragments + g_cache_line_size,
671 				tail_bytes);
672 		}
673 
674 		down(&g_free_fragments_mutex);
675 		*(char **) fragments = g_free_fragments;
676 		g_free_fragments = fragments;
677 		up(&g_free_fragments_mutex);
678 		up(&g_free_fragments_sema);
679 	}
680 
681 	if (pagelist->type != PAGELIST_WRITE) {
682 		for (i = 0; i < num_pages; i++) {
683 			vm_page_dirty(pages[i]);
684 			pagelist_page_free(pages[i]);
685 		}
686 	}
687 
688 #if defined(__aarch64__)
689 	/* XXXMDC necessary? */
690 	dsb(sy);
691 #endif
692 
693 	bus_dmamap_unload(bi->pagelist_dma_tag, bi->pagelist_dma_map);
694 	bus_dmamem_free(bi->pagelist_dma_tag, bi->pagelist, bi->pagelist_dma_map);
695 	bus_dma_tag_destroy(bi->pagelist_dma_tag);
696 
697 	free(bi, M_VCPAGELIST);
698 }
699