2 * Copyright (c) 2010-2012 Broadcom. All rights reserved.
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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.
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.
21 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
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31 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
34 #include <linux/kernel.h>
35 #include <linux/types.h>
36 #include <linux/errno.h>
37 #include <linux/interrupt.h>
38 #include <linux/pagemap.h>
39 #include <linux/dma-mapping.h>
41 #include <linux/platform_device.h>
42 #include <linux/uaccess.h>
45 #include <soc/bcm2835/raspberrypi-firmware.h>
47 #define TOTAL_SLOTS (VCHIQ_SLOT_ZERO_SLOTS + 2 * 32)
49 #include "vchiq_arm.h"
50 #include "vchiq_connected.h"
51 #include "vchiq_killable.h"
52 #include "vchiq_pagelist.h"
54 #define MAX_FRAGMENTS (VCHIQ_NUM_CURRENT_BULKS * 2)
56 #define VCHIQ_PLATFORM_FRAGMENTS_OFFSET_IDX 0
57 #define VCHIQ_PLATFORM_FRAGMENTS_COUNT_IDX 1
62 typedef struct vchiq_2835_state_struct {
64 VCHIQ_ARM_STATE_T arm_state;
65 } VCHIQ_2835_ARM_STATE_T;
67 struct vchiq_pagelist_info {
69 size_t pagelist_buffer_size;
71 enum dma_data_direction dma_dir;
72 unsigned int num_pages;
73 unsigned int pages_need_release;
75 struct scatterlist *scatterlist;
76 unsigned int scatterlist_mapped;
79 static void __iomem *g_regs;
80 static unsigned int g_cache_line_size = sizeof(CACHE_LINE_SIZE);
81 static unsigned int g_fragments_size;
82 static char *g_fragments_base;
83 static char *g_free_fragments;
84 static struct semaphore g_free_fragments_sema;
85 static struct device *g_dev;
87 extern int vchiq_arm_log_level;
89 static DEFINE_SEMAPHORE(g_free_fragments_mutex);
92 vchiq_doorbell_irq(int irq, void *dev_id);
94 static struct vchiq_pagelist_info *
95 create_pagelist(char __user *buf, size_t count, unsigned short type,
96 struct task_struct *task);
99 free_pagelist(struct vchiq_pagelist_info *pagelistinfo,
102 int vchiq_platform_init(struct platform_device *pdev, VCHIQ_STATE_T *state)
104 struct device *dev = &pdev->dev;
105 struct rpi_firmware *fw = platform_get_drvdata(pdev);
106 VCHIQ_SLOT_ZERO_T *vchiq_slot_zero;
107 struct resource *res;
109 dma_addr_t slot_phys;
111 int slot_mem_size, frag_mem_size;
115 * VCHI messages between the CPU and firmware use
116 * 32-bit bus addresses.
118 err = dma_set_mask_and_coherent(dev, DMA_BIT_MASK(32));
123 err = of_property_read_u32(dev->of_node, "cache-line-size",
127 dev_err(dev, "Missing cache-line-size property\n");
131 g_fragments_size = 2 * g_cache_line_size;
133 /* Allocate space for the channels in coherent memory */
134 slot_mem_size = PAGE_ALIGN(TOTAL_SLOTS * VCHIQ_SLOT_SIZE);
135 frag_mem_size = PAGE_ALIGN(g_fragments_size * MAX_FRAGMENTS);
137 slot_mem = dmam_alloc_coherent(dev, slot_mem_size + frag_mem_size,
138 &slot_phys, GFP_KERNEL);
140 dev_err(dev, "could not allocate DMA memory\n");
144 WARN_ON(((unsigned long)slot_mem & (PAGE_SIZE - 1)) != 0);
146 vchiq_slot_zero = vchiq_init_slots(slot_mem, slot_mem_size);
147 if (!vchiq_slot_zero)
150 vchiq_slot_zero->platform_data[VCHIQ_PLATFORM_FRAGMENTS_OFFSET_IDX] =
151 (int)slot_phys + slot_mem_size;
152 vchiq_slot_zero->platform_data[VCHIQ_PLATFORM_FRAGMENTS_COUNT_IDX] =
155 g_fragments_base = (char *)slot_mem + slot_mem_size;
156 slot_mem_size += frag_mem_size;
158 g_free_fragments = g_fragments_base;
159 for (i = 0; i < (MAX_FRAGMENTS - 1); i++) {
160 *(char **)&g_fragments_base[i*g_fragments_size] =
161 &g_fragments_base[(i + 1)*g_fragments_size];
163 *(char **)&g_fragments_base[i * g_fragments_size] = NULL;
164 sema_init(&g_free_fragments_sema, MAX_FRAGMENTS);
166 if (vchiq_init_state(state, vchiq_slot_zero, 0) != VCHIQ_SUCCESS)
169 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
170 g_regs = devm_ioremap_resource(&pdev->dev, res);
172 return PTR_ERR(g_regs);
174 irq = platform_get_irq(pdev, 0);
176 dev_err(dev, "failed to get IRQ\n");
180 err = devm_request_irq(dev, irq, vchiq_doorbell_irq, IRQF_IRQPOLL,
181 "VCHIQ doorbell", state);
183 dev_err(dev, "failed to register irq=%d\n", irq);
187 /* Send the base address of the slots to VideoCore */
188 channelbase = slot_phys;
189 err = rpi_firmware_property(fw, RPI_FIRMWARE_VCHIQ_INIT,
190 &channelbase, sizeof(channelbase));
191 if (err || channelbase) {
192 dev_err(dev, "failed to set channelbase\n");
193 return err ? : -ENXIO;
197 vchiq_log_info(vchiq_arm_log_level,
198 "vchiq_init - done (slots %pK, phys %pad)",
199 vchiq_slot_zero, &slot_phys);
201 vchiq_call_connected_callbacks();
207 vchiq_platform_init_state(VCHIQ_STATE_T *state)
209 VCHIQ_STATUS_T status = VCHIQ_SUCCESS;
211 state->platform_state = kzalloc(sizeof(VCHIQ_2835_ARM_STATE_T), GFP_KERNEL);
212 ((VCHIQ_2835_ARM_STATE_T *)state->platform_state)->inited = 1;
213 status = vchiq_arm_init_state(state, &((VCHIQ_2835_ARM_STATE_T *)state->platform_state)->arm_state);
214 if (status != VCHIQ_SUCCESS)
216 ((VCHIQ_2835_ARM_STATE_T *)state->platform_state)->inited = 0;
222 vchiq_platform_get_arm_state(VCHIQ_STATE_T *state)
224 if (!((VCHIQ_2835_ARM_STATE_T *)state->platform_state)->inited)
228 return &((VCHIQ_2835_ARM_STATE_T *)state->platform_state)->arm_state;
232 remote_event_signal(REMOTE_EVENT_T *event)
238 dsb(sy); /* data barrier operation */
241 writel(0, g_regs + BELL2); /* trigger vc interrupt */
245 vchiq_prepare_bulk_data(VCHIQ_BULK_T *bulk, VCHI_MEM_HANDLE_T memhandle,
246 void *offset, int size, int dir)
248 struct vchiq_pagelist_info *pagelistinfo;
250 WARN_ON(memhandle != VCHI_MEM_HANDLE_INVALID);
252 pagelistinfo = create_pagelist((char __user *)offset, size,
253 (dir == VCHIQ_BULK_RECEIVE)
261 bulk->handle = memhandle;
262 bulk->data = (void *)(unsigned long)pagelistinfo->dma_addr;
265 * Store the pagelistinfo address in remote_data,
266 * which isn't used by the slave.
268 bulk->remote_data = pagelistinfo;
270 return VCHIQ_SUCCESS;
274 vchiq_complete_bulk(VCHIQ_BULK_T *bulk)
276 if (bulk && bulk->remote_data && bulk->actual)
277 free_pagelist((struct vchiq_pagelist_info *)bulk->remote_data,
282 vchiq_transfer_bulk(VCHIQ_BULK_T *bulk)
285 * This should only be called on the master (VideoCore) side, but
286 * provide an implementation to avoid the need for ifdefery.
292 vchiq_dump_platform_state(void *dump_context)
297 len = snprintf(buf, sizeof(buf),
298 " Platform: 2835 (VC master)");
299 vchiq_dump(dump_context, buf, len + 1);
303 vchiq_platform_suspend(VCHIQ_STATE_T *state)
309 vchiq_platform_resume(VCHIQ_STATE_T *state)
311 return VCHIQ_SUCCESS;
315 vchiq_platform_paused(VCHIQ_STATE_T *state)
320 vchiq_platform_resumed(VCHIQ_STATE_T *state)
325 vchiq_platform_videocore_wanted(VCHIQ_STATE_T *state)
327 return 1; // autosuspend not supported - videocore always wanted
331 vchiq_platform_use_suspend_timer(void)
336 vchiq_dump_platform_use_state(VCHIQ_STATE_T *state)
338 vchiq_log_info(vchiq_arm_log_level, "Suspend timer not in use");
341 vchiq_platform_handle_timeout(VCHIQ_STATE_T *state)
350 vchiq_doorbell_irq(int irq, void *dev_id)
352 VCHIQ_STATE_T *state = dev_id;
353 irqreturn_t ret = IRQ_NONE;
356 /* Read (and clear) the doorbell */
357 status = readl(g_regs + BELL0);
359 if (status & 0x4) { /* Was the doorbell rung? */
360 remote_event_pollall(state);
368 cleaup_pagelistinfo(struct vchiq_pagelist_info *pagelistinfo)
370 if (pagelistinfo->scatterlist_mapped) {
371 dma_unmap_sg(g_dev, pagelistinfo->scatterlist,
372 pagelistinfo->num_pages, pagelistinfo->dma_dir);
375 if (pagelistinfo->pages_need_release) {
378 for (i = 0; i < pagelistinfo->num_pages; i++)
379 put_page(pagelistinfo->pages[i]);
382 dma_free_coherent(g_dev, pagelistinfo->pagelist_buffer_size,
383 pagelistinfo->pagelist, pagelistinfo->dma_addr);
386 /* There is a potential problem with partial cache lines (pages?)
387 ** at the ends of the block when reading. If the CPU accessed anything in
388 ** the same line (page?) then it may have pulled old data into the cache,
389 ** obscuring the new data underneath. We can solve this by transferring the
390 ** partial cache lines separately, and allowing the ARM to copy into the
394 static struct vchiq_pagelist_info *
395 create_pagelist(char __user *buf, size_t count, unsigned short type,
396 struct task_struct *task)
398 PAGELIST_T *pagelist;
399 struct vchiq_pagelist_info *pagelistinfo;
402 unsigned int num_pages, offset, i, k;
404 size_t pagelist_size;
405 struct scatterlist *scatterlist, *sg;
409 offset = ((unsigned int)(unsigned long)buf & (PAGE_SIZE - 1));
410 num_pages = DIV_ROUND_UP(count + offset, PAGE_SIZE);
412 pagelist_size = sizeof(PAGELIST_T) +
413 (num_pages * sizeof(u32)) +
414 (num_pages * sizeof(pages[0]) +
415 (num_pages * sizeof(struct scatterlist))) +
416 sizeof(struct vchiq_pagelist_info);
418 /* Allocate enough storage to hold the page pointers and the page
421 pagelist = dma_zalloc_coherent(g_dev,
426 vchiq_log_trace(vchiq_arm_log_level, "create_pagelist - %pK",
431 addrs = pagelist->addrs;
432 pages = (struct page **)(addrs + num_pages);
433 scatterlist = (struct scatterlist *)(pages + num_pages);
434 pagelistinfo = (struct vchiq_pagelist_info *)
435 (scatterlist + num_pages);
437 pagelist->length = count;
438 pagelist->type = type;
439 pagelist->offset = offset;
441 /* Populate the fields of the pagelistinfo structure */
442 pagelistinfo->pagelist = pagelist;
443 pagelistinfo->pagelist_buffer_size = pagelist_size;
444 pagelistinfo->dma_addr = dma_addr;
445 pagelistinfo->dma_dir = (type == PAGELIST_WRITE) ?
446 DMA_TO_DEVICE : DMA_FROM_DEVICE;
447 pagelistinfo->num_pages = num_pages;
448 pagelistinfo->pages_need_release = 0;
449 pagelistinfo->pages = pages;
450 pagelistinfo->scatterlist = scatterlist;
451 pagelistinfo->scatterlist_mapped = 0;
453 if (is_vmalloc_addr(buf)) {
454 unsigned long length = count;
455 unsigned int off = offset;
457 for (actual_pages = 0; actual_pages < num_pages;
459 struct page *pg = vmalloc_to_page(buf + (actual_pages *
461 size_t bytes = PAGE_SIZE - off;
465 pages[actual_pages] = pg;
469 /* do not try and release vmalloc pages */
471 down_read(&task->mm->mmap_sem);
472 actual_pages = get_user_pages(
473 (unsigned long)buf & ~(PAGE_SIZE - 1),
475 (type == PAGELIST_READ) ? FOLL_WRITE : 0,
478 up_read(&task->mm->mmap_sem);
480 if (actual_pages != num_pages) {
481 vchiq_log_info(vchiq_arm_log_level,
482 "create_pagelist - only %d/%d pages locked",
486 /* This is probably due to the process being killed */
487 while (actual_pages > 0)
490 put_page(pages[actual_pages]);
492 cleaup_pagelistinfo(pagelistinfo);
495 /* release user pages */
496 pagelistinfo->pages_need_release = 1;
500 * Initialize the scatterlist so that the magic cookie
501 * is filled if debugging is enabled
503 sg_init_table(scatterlist, num_pages);
504 /* Now set the pages for each scatterlist */
505 for (i = 0; i < num_pages; i++)
506 sg_set_page(scatterlist + i, pages[i], PAGE_SIZE, 0);
508 dma_buffers = dma_map_sg(g_dev,
511 pagelistinfo->dma_dir);
513 if (dma_buffers == 0) {
514 cleaup_pagelistinfo(pagelistinfo);
518 pagelistinfo->scatterlist_mapped = 1;
520 /* Combine adjacent blocks for performance */
522 for_each_sg(scatterlist, sg, dma_buffers, i) {
523 u32 len = sg_dma_len(sg);
524 u32 addr = sg_dma_address(sg);
526 /* Note: addrs is the address + page_count - 1
527 * The firmware expects the block to be page
528 * aligned and a multiple of the page size
531 WARN_ON(len & ~PAGE_MASK);
532 WARN_ON(addr & ~PAGE_MASK);
534 ((addrs[k - 1] & PAGE_MASK) |
535 ((addrs[k - 1] & ~PAGE_MASK) + 1) << PAGE_SHIFT)
537 addrs[k - 1] += (len >> PAGE_SHIFT);
539 addrs[k++] = addr | ((len >> PAGE_SHIFT) - 1);
543 /* Partial cache lines (fragments) require special measures */
544 if ((type == PAGELIST_READ) &&
545 ((pagelist->offset & (g_cache_line_size - 1)) ||
546 ((pagelist->offset + pagelist->length) &
547 (g_cache_line_size - 1)))) {
550 if (down_interruptible(&g_free_fragments_sema) != 0) {
551 cleaup_pagelistinfo(pagelistinfo);
555 WARN_ON(g_free_fragments == NULL);
557 down(&g_free_fragments_mutex);
558 fragments = g_free_fragments;
559 WARN_ON(fragments == NULL);
560 g_free_fragments = *(char **) g_free_fragments;
561 up(&g_free_fragments_mutex);
562 pagelist->type = PAGELIST_READ_WITH_FRAGMENTS +
563 (fragments - g_fragments_base) / g_fragments_size;
570 free_pagelist(struct vchiq_pagelist_info *pagelistinfo,
574 PAGELIST_T *pagelist = pagelistinfo->pagelist;
575 struct page **pages = pagelistinfo->pages;
576 unsigned int num_pages = pagelistinfo->num_pages;
578 vchiq_log_trace(vchiq_arm_log_level, "free_pagelist - %pK, %d",
579 pagelistinfo->pagelist, actual);
582 * NOTE: dma_unmap_sg must be called before the
583 * cpu can touch any of the data/pages.
585 dma_unmap_sg(g_dev, pagelistinfo->scatterlist,
586 pagelistinfo->num_pages, pagelistinfo->dma_dir);
587 pagelistinfo->scatterlist_mapped = 0;
589 /* Deal with any partial cache lines (fragments) */
590 if (pagelist->type >= PAGELIST_READ_WITH_FRAGMENTS) {
591 char *fragments = g_fragments_base +
592 (pagelist->type - PAGELIST_READ_WITH_FRAGMENTS) *
594 int head_bytes, tail_bytes;
596 head_bytes = (g_cache_line_size - pagelist->offset) &
597 (g_cache_line_size - 1);
598 tail_bytes = (pagelist->offset + actual) &
599 (g_cache_line_size - 1);
601 if ((actual >= 0) && (head_bytes != 0)) {
602 if (head_bytes > actual)
605 memcpy((char *)page_address(pages[0]) +
610 if ((actual >= 0) && (head_bytes < actual) &&
612 memcpy((char *)page_address(pages[num_pages - 1]) +
613 ((pagelist->offset + actual) &
614 (PAGE_SIZE - 1) & ~(g_cache_line_size - 1)),
615 fragments + g_cache_line_size,
619 down(&g_free_fragments_mutex);
620 *(char **)fragments = g_free_fragments;
621 g_free_fragments = fragments;
622 up(&g_free_fragments_mutex);
623 up(&g_free_fragments_sema);
626 /* Need to mark all the pages dirty. */
627 if (pagelist->type != PAGELIST_WRITE &&
628 pagelistinfo->pages_need_release) {
629 for (i = 0; i < num_pages; i++)
630 set_page_dirty(pages[i]);
633 cleaup_pagelistinfo(pagelistinfo);