diff options
Diffstat (limited to 'drivers/gpu/host1x/cdma.c')
| -rw-r--r-- | drivers/gpu/host1x/cdma.c | 491 |
1 files changed, 491 insertions, 0 deletions
diff --git a/drivers/gpu/host1x/cdma.c b/drivers/gpu/host1x/cdma.c new file mode 100644 index 000000000000..de72172d3b5f --- /dev/null +++ b/drivers/gpu/host1x/cdma.c @@ -0,0 +1,491 @@ +/* + * Tegra host1x Command DMA + * + * Copyright (c) 2010-2013, NVIDIA Corporation. + * + * This program is free software; you can redistribute it and/or modify it + * under the terms and conditions of the GNU General Public License, + * version 2, as published by the Free Software Foundation. + * + * This program is distributed in the hope it will be useful, but WITHOUT + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for + * more details. + * + * You should have received a copy of the GNU General Public License + * along with this program. If not, see <http://www.gnu.org/licenses/>. + */ + + +#include <asm/cacheflush.h> +#include <linux/device.h> +#include <linux/dma-mapping.h> +#include <linux/interrupt.h> +#include <linux/kernel.h> +#include <linux/kfifo.h> +#include <linux/slab.h> +#include <trace/events/host1x.h> + +#include "cdma.h" +#include "channel.h" +#include "dev.h" +#include "debug.h" +#include "host1x_bo.h" +#include "job.h" + +/* + * push_buffer + * + * The push buffer is a circular array of words to be fetched by command DMA. + * Note that it works slightly differently to the sync queue; fence == pos + * means that the push buffer is full, not empty. + */ + +#define HOST1X_PUSHBUFFER_SLOTS 512 + +/* + * Clean up push buffer resources + */ +static void host1x_pushbuffer_destroy(struct push_buffer *pb) +{ + struct host1x_cdma *cdma = pb_to_cdma(pb); + struct host1x *host1x = cdma_to_host1x(cdma); + + if (pb->phys != 0) + dma_free_writecombine(host1x->dev, pb->size_bytes + 4, + pb->mapped, pb->phys); + + pb->mapped = NULL; + pb->phys = 0; +} + +/* + * Init push buffer resources + */ +static int host1x_pushbuffer_init(struct push_buffer *pb) +{ + struct host1x_cdma *cdma = pb_to_cdma(pb); + struct host1x *host1x = cdma_to_host1x(cdma); + + pb->mapped = NULL; + pb->phys = 0; + pb->size_bytes = HOST1X_PUSHBUFFER_SLOTS * 8; + + /* initialize buffer pointers */ + pb->fence = pb->size_bytes - 8; + pb->pos = 0; + + /* allocate and map pushbuffer memory */ + pb->mapped = dma_alloc_writecombine(host1x->dev, pb->size_bytes + 4, + &pb->phys, GFP_KERNEL); + if (!pb->mapped) + goto fail; + + host1x_hw_pushbuffer_init(host1x, pb); + + return 0; + +fail: + host1x_pushbuffer_destroy(pb); + return -ENOMEM; +} + +/* + * Push two words to the push buffer + * Caller must ensure push buffer is not full + */ +static void host1x_pushbuffer_push(struct push_buffer *pb, u32 op1, u32 op2) +{ + u32 pos = pb->pos; + u32 *p = (u32 *)((u32)pb->mapped + pos); + WARN_ON(pos == pb->fence); + *(p++) = op1; + *(p++) = op2; + pb->pos = (pos + 8) & (pb->size_bytes - 1); +} + +/* + * Pop a number of two word slots from the push buffer + * Caller must ensure push buffer is not empty + */ +static void host1x_pushbuffer_pop(struct push_buffer *pb, unsigned int slots) +{ + /* Advance the next write position */ + pb->fence = (pb->fence + slots * 8) & (pb->size_bytes - 1); +} + +/* + * Return the number of two word slots free in the push buffer + */ +static u32 host1x_pushbuffer_space(struct push_buffer *pb) +{ + return ((pb->fence - pb->pos) & (pb->size_bytes - 1)) / 8; +} + +/* + * Sleep (if necessary) until the requested event happens + * - CDMA_EVENT_SYNC_QUEUE_EMPTY : sync queue is completely empty. + * - Returns 1 + * - CDMA_EVENT_PUSH_BUFFER_SPACE : there is space in the push buffer + * - Return the amount of space (> 0) + * Must be called with the cdma lock held. + */ +unsigned int host1x_cdma_wait_locked(struct host1x_cdma *cdma, + enum cdma_event event) +{ + for (;;) { + unsigned int space; + + if (event == CDMA_EVENT_SYNC_QUEUE_EMPTY) + space = list_empty(&cdma->sync_queue) ? 1 : 0; + else if (event == CDMA_EVENT_PUSH_BUFFER_SPACE) { + struct push_buffer *pb = &cdma->push_buffer; + space = host1x_pushbuffer_space(pb); + } else { + WARN_ON(1); + return -EINVAL; + } + + if (space) + return space; + + trace_host1x_wait_cdma(dev_name(cdma_to_channel(cdma)->dev), + event); + + /* If somebody has managed to already start waiting, yield */ + if (cdma->event != CDMA_EVENT_NONE) { + mutex_unlock(&cdma->lock); + schedule(); + mutex_lock(&cdma->lock); + continue; + } + cdma->event = event; + + mutex_unlock(&cdma->lock); + down(&cdma->sem); + mutex_lock(&cdma->lock); + } + return 0; +} + +/* + * Start timer that tracks the time spent by the job. + * Must be called with the cdma lock held. + */ +static void cdma_start_timer_locked(struct host1x_cdma *cdma, + struct host1x_job *job) +{ + struct host1x *host = cdma_to_host1x(cdma); + + if (cdma->timeout.client) { + /* timer already started */ + return; + } + + cdma->timeout.client = job->client; + cdma->timeout.syncpt = host1x_syncpt_get(host, job->syncpt_id); + cdma->timeout.syncpt_val = job->syncpt_end; + cdma->timeout.start_ktime = ktime_get(); + + schedule_delayed_work(&cdma->timeout.wq, + msecs_to_jiffies(job->timeout)); +} + +/* + * Stop timer when a buffer submission completes. + * Must be called with the cdma lock held. + */ +static void stop_cdma_timer_locked(struct host1x_cdma *cdma) +{ + cancel_delayed_work(&cdma->timeout.wq); + cdma->timeout.client = 0; +} + +/* + * For all sync queue entries that have already finished according to the + * current sync point registers: + * - unpin & unref their mems + * - pop their push buffer slots + * - remove them from the sync queue + * This is normally called from the host code's worker thread, but can be + * called manually if necessary. + * Must be called with the cdma lock held. + */ +static void update_cdma_locked(struct host1x_cdma *cdma) +{ + bool signal = false; + struct host1x *host1x = cdma_to_host1x(cdma); + struct host1x_job *job, *n; + + /* If CDMA is stopped, queue is cleared and we can return */ + if (!cdma->running) + return; + + /* + * Walk the sync queue, reading the sync point registers as necessary, + * to consume as many sync queue entries as possible without blocking + */ + list_for_each_entry_safe(job, n, &cdma->sync_queue, list) { + struct host1x_syncpt *sp = + host1x_syncpt_get(host1x, job->syncpt_id); + + /* Check whether this syncpt has completed, and bail if not */ + if (!host1x_syncpt_is_expired(sp, job->syncpt_end)) { + /* Start timer on next pending syncpt */ + if (job->timeout) + cdma_start_timer_locked(cdma, job); + break; + } + + /* Cancel timeout, when a buffer completes */ + if (cdma->timeout.client) + stop_cdma_timer_locked(cdma); + + /* Unpin the memory */ + host1x_job_unpin(job); + + /* Pop push buffer slots */ + if (job->num_slots) { + struct push_buffer *pb = &cdma->push_buffer; + host1x_pushbuffer_pop(pb, job->num_slots); + if (cdma->event == CDMA_EVENT_PUSH_BUFFER_SPACE) + signal = true; + } + + list_del(&job->list); + host1x_job_put(job); + } + + if (cdma->event == CDMA_EVENT_SYNC_QUEUE_EMPTY && + list_empty(&cdma->sync_queue)) + signal = true; + + if (signal) { + cdma->event = CDMA_EVENT_NONE; + up(&cdma->sem); + } +} + +void host1x_cdma_update_sync_queue(struct host1x_cdma *cdma, + struct device *dev) +{ + u32 restart_addr; + u32 syncpt_incrs; + struct host1x_job *job = NULL; + u32 syncpt_val; + struct host1x *host1x = cdma_to_host1x(cdma); + + syncpt_val = host1x_syncpt_load(cdma->timeout.syncpt); + + dev_dbg(dev, "%s: starting cleanup (thresh %d)\n", + __func__, syncpt_val); + + /* + * Move the sync_queue read pointer to the first entry that hasn't + * completed based on the current HW syncpt value. It's likely there + * won't be any (i.e. we're still at the head), but covers the case + * where a syncpt incr happens just prior/during the teardown. + */ + + dev_dbg(dev, "%s: skip completed buffers still in sync_queue\n", + __func__); + + list_for_each_entry(job, &cdma->sync_queue, list) { + if (syncpt_val < job->syncpt_end) + break; + + host1x_job_dump(dev, job); + } + + /* + * Walk the sync_queue, first incrementing with the CPU syncpts that + * are partially executed (the first buffer) or fully skipped while + * still in the current context (slots are also NOP-ed). + * + * At the point contexts are interleaved, syncpt increments must be + * done inline with the pushbuffer from a GATHER buffer to maintain + * the order (slots are modified to be a GATHER of syncpt incrs). + * + * Note: save in restart_addr the location where the timed out buffer + * started in the PB, so we can start the refetch from there (with the + * modified NOP-ed PB slots). This lets things appear to have completed + * properly for this buffer and resources are freed. + */ + + dev_dbg(dev, "%s: perform CPU incr on pending same ctx buffers\n", + __func__); + + if (!list_empty(&cdma->sync_queue)) + restart_addr = job->first_get; + else + restart_addr = cdma->last_pos; + + /* do CPU increments as long as this context continues */ + list_for_each_entry_from(job, &cdma->sync_queue, list) { + /* different context, gets us out of this loop */ + if (job->client != cdma->timeout.client) + break; + + /* won't need a timeout when replayed */ + job->timeout = 0; + + syncpt_incrs = job->syncpt_end - syncpt_val; + dev_dbg(dev, "%s: CPU incr (%d)\n", __func__, syncpt_incrs); + + host1x_job_dump(dev, job); + + /* safe to use CPU to incr syncpts */ + host1x_hw_cdma_timeout_cpu_incr(host1x, cdma, job->first_get, + syncpt_incrs, job->syncpt_end, + job->num_slots); + + syncpt_val += syncpt_incrs; + } + + /* The following sumbits from the same client may be dependent on the + * failed submit and therefore they may fail. Force a small timeout + * to make the queue cleanup faster */ + + list_for_each_entry_from(job, &cdma->sync_queue, list) + if (job->client == cdma->timeout.client) + job->timeout = min_t(unsigned int, job->timeout, 500); + + dev_dbg(dev, "%s: finished sync_queue modification\n", __func__); + + /* roll back DMAGET and start up channel again */ + host1x_hw_cdma_resume(host1x, cdma, restart_addr); +} + +/* + * Create a cdma + */ +int host1x_cdma_init(struct host1x_cdma *cdma) +{ + int err; + + mutex_init(&cdma->lock); + sema_init(&cdma->sem, 0); + + INIT_LIST_HEAD(&cdma->sync_queue); + + cdma->event = CDMA_EVENT_NONE; + cdma->running = false; + cdma->torndown = false; + + err = host1x_pushbuffer_init(&cdma->push_buffer); + if (err) + return err; + return 0; +} + +/* + * Destroy a cdma + */ +int host1x_cdma_deinit(struct host1x_cdma *cdma) +{ + struct push_buffer *pb = &cdma->push_buffer; + struct host1x *host1x = cdma_to_host1x(cdma); + + if (cdma->running) { + pr_warn("%s: CDMA still running\n", __func__); + return -EBUSY; + } + + host1x_pushbuffer_destroy(pb); + host1x_hw_cdma_timeout_destroy(host1x, cdma); + + return 0; +} + +/* + * Begin a cdma submit + */ +int host1x_cdma_begin(struct host1x_cdma *cdma, struct host1x_job *job) +{ + struct host1x *host1x = cdma_to_host1x(cdma); + + mutex_lock(&cdma->lock); + + if (job->timeout) { + /* init state on first submit with timeout value */ + if (!cdma->timeout.initialized) { + int err; + err = host1x_hw_cdma_timeout_init(host1x, cdma, + job->syncpt_id); + if (err) { + mutex_unlock(&cdma->lock); + return err; + } + } + } + if (!cdma->running) + host1x_hw_cdma_start(host1x, cdma); + + cdma->slots_free = 0; + cdma->slots_used = 0; + cdma->first_get = cdma->push_buffer.pos; + + trace_host1x_cdma_begin(dev_name(job->channel->dev)); + return 0; +} + +/* + * Push two words into a push buffer slot + * Blocks as necessary if the push buffer is full. + */ +void host1x_cdma_push(struct host1x_cdma *cdma, u32 op1, u32 op2) +{ + struct host1x *host1x = cdma_to_host1x(cdma); + struct push_buffer *pb = &cdma->push_buffer; + u32 slots_free = cdma->slots_free; + + if (host1x_debug_trace_cmdbuf) + trace_host1x_cdma_push(dev_name(cdma_to_channel(cdma)->dev), + op1, op2); + + if (slots_free == 0) { + host1x_hw_cdma_flush(host1x, cdma); + slots_free = host1x_cdma_wait_locked(cdma, + CDMA_EVENT_PUSH_BUFFER_SPACE); + } + cdma->slots_free = slots_free - 1; + cdma->slots_used++; + host1x_pushbuffer_push(pb, op1, op2); +} + +/* + * End a cdma submit + * Kick off DMA, add job to the sync queue, and a number of slots to be freed + * from the pushbuffer. The handles for a submit must all be pinned at the same + * time, but they can be unpinned in smaller chunks. + */ +void host1x_cdma_end(struct host1x_cdma *cdma, + struct host1x_job *job) +{ + struct host1x *host1x = cdma_to_host1x(cdma); + bool idle = list_empty(&cdma->sync_queue); + + host1x_hw_cdma_flush(host1x, cdma); + + job->first_get = cdma->first_get; + job->num_slots = cdma->slots_used; + host1x_job_get(job); + list_add_tail(&job->list, &cdma->sync_queue); + + /* start timer on idle -> active transitions */ + if (job->timeout && idle) + cdma_start_timer_locked(cdma, job); + + trace_host1x_cdma_end(dev_name(job->channel->dev)); + mutex_unlock(&cdma->lock); +} + +/* + * Update cdma state according to current sync point values + */ +void host1x_cdma_update(struct host1x_cdma *cdma) +{ + mutex_lock(&cdma->lock); + update_cdma_locked(cdma); + mutex_unlock(&cdma->lock); +} |