diff options
Diffstat (limited to 'drivers/gpu/host1x/cdma.c')
-rw-r--r-- | drivers/gpu/host1x/cdma.c | 693 |
1 files changed, 693 insertions, 0 deletions
diff --git a/drivers/gpu/host1x/cdma.c b/drivers/gpu/host1x/cdma.c new file mode 100644 index 0000000000..d1336e438f --- /dev/null +++ b/drivers/gpu/host1x/cdma.c @@ -0,0 +1,693 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Tegra host1x Command DMA + * + * Copyright (c) 2010-2013, NVIDIA Corporation. + */ + + +#include <asm/cacheflush.h> +#include <linux/device.h> +#include <linux/dma-mapping.h> +#include <linux/host1x.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 "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. + */ + +/* + * Typically the commands written into the push buffer are a pair of words. We + * use slots to represent each of these pairs and to simplify things. Note the + * strange number of slots allocated here. 512 slots will fit exactly within a + * single memory page. We also need one additional word at the end of the push + * buffer for the RESTART opcode that will instruct the CDMA to jump back to + * the beginning of the push buffer. With 512 slots, this means that we'll use + * 2 memory pages and waste 4092 bytes of the second page that will never be + * used. + */ +#define HOST1X_PUSHBUFFER_SLOTS 511 + +/* + * 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->mapped) + return; + + if (host1x->domain) { + iommu_unmap(host1x->domain, pb->dma, pb->alloc_size); + free_iova(&host1x->iova, iova_pfn(&host1x->iova, pb->dma)); + } + + dma_free_wc(host1x->dev, pb->alloc_size, 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); + struct iova *alloc; + u32 size; + int err; + + pb->mapped = NULL; + pb->phys = 0; + pb->size = HOST1X_PUSHBUFFER_SLOTS * 8; + + size = pb->size + 4; + + /* initialize buffer pointers */ + pb->fence = pb->size - 8; + pb->pos = 0; + + if (host1x->domain) { + unsigned long shift; + + size = iova_align(&host1x->iova, size); + + pb->mapped = dma_alloc_wc(host1x->dev, size, &pb->phys, + GFP_KERNEL); + if (!pb->mapped) + return -ENOMEM; + + shift = iova_shift(&host1x->iova); + alloc = alloc_iova(&host1x->iova, size >> shift, + host1x->iova_end >> shift, true); + if (!alloc) { + err = -ENOMEM; + goto iommu_free_mem; + } + + pb->dma = iova_dma_addr(&host1x->iova, alloc); + err = iommu_map(host1x->domain, pb->dma, pb->phys, size, + IOMMU_READ, GFP_KERNEL); + if (err) + goto iommu_free_iova; + } else { + pb->mapped = dma_alloc_wc(host1x->dev, size, &pb->phys, + GFP_KERNEL); + if (!pb->mapped) + return -ENOMEM; + + pb->dma = pb->phys; + } + + pb->alloc_size = size; + + host1x_hw_pushbuffer_init(host1x, pb); + + return 0; + +iommu_free_iova: + __free_iova(&host1x->iova, alloc); +iommu_free_mem: + dma_free_wc(host1x->dev, size, pb->mapped, pb->phys); + + return err; +} + +/* + * 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 *p = (u32 *)((void *)pb->mapped + pb->pos); + + WARN_ON(pb->pos == pb->fence); + *(p++) = op1; + *(p++) = op2; + pb->pos += 8; + + if (pb->pos >= pb->size) + pb->pos -= pb->size; +} + +/* + * 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 += slots * 8; + + if (pb->fence >= pb->size) + pb->fence -= pb->size; +} + +/* + * Return the number of two word slots free in the push buffer + */ +static u32 host1x_pushbuffer_space(struct push_buffer *pb) +{ + unsigned int fence = pb->fence; + + if (pb->fence < pb->pos) + fence += pb->size; + + return (fence - pb->pos) / 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 (;;) { + struct push_buffer *pb = &cdma->push_buffer; + unsigned int space; + + switch (event) { + case CDMA_EVENT_SYNC_QUEUE_EMPTY: + space = list_empty(&cdma->sync_queue) ? 1 : 0; + break; + + case CDMA_EVENT_PUSH_BUFFER_SPACE: + space = host1x_pushbuffer_space(pb); + break; + + default: + 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); + wait_for_completion(&cdma->complete); + mutex_lock(&cdma->lock); + } + + return 0; +} + +/* + * Sleep (if necessary) until the push buffer has enough free space. + * + * Must be called with the cdma lock held. + */ +static int host1x_cdma_wait_pushbuffer_space(struct host1x *host1x, + struct host1x_cdma *cdma, + unsigned int needed) +{ + while (true) { + struct push_buffer *pb = &cdma->push_buffer; + unsigned int space; + + space = host1x_pushbuffer_space(pb); + if (space >= needed) + break; + + trace_host1x_wait_cdma(dev_name(cdma_to_channel(cdma)->dev), + CDMA_EVENT_PUSH_BUFFER_SPACE); + + host1x_hw_cdma_flush(host1x, cdma); + + /* 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 = CDMA_EVENT_PUSH_BUFFER_SPACE; + + mutex_unlock(&cdma->lock); + wait_for_completion(&cdma->complete); + 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) +{ + if (cdma->timeout.client) { + /* timer already started */ + return; + } + + cdma->timeout.client = job->client; + cdma->timeout.syncpt = job->syncpt; + 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 = NULL; +} + +/* + * 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_job *job, *n; + + /* + * 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 = job->syncpt; + + /* Check whether this syncpt has completed, and bail if not */ + if (!host1x_syncpt_is_expired(sp, job->syncpt_end) && + !job->cancelled) { + /* 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; + complete(&cdma->complete); + } +} + +void host1x_cdma_update_sync_queue(struct host1x_cdma *cdma, + struct device *dev) +{ + struct host1x *host1x = cdma_to_host1x(cdma); + u32 restart_addr, syncpt_incrs, syncpt_val; + struct host1x_job *job, *next_job = NULL; + + 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) { + + if (!list_is_last(&job->list, &cdma->sync_queue)) + next_job = list_next_entry(job, list); + + goto syncpt_incr; + } + + host1x_job_dump(dev, job); + } + + /* all jobs have been completed */ + job = NULL; + +syncpt_incr: + + /* + * Increment with CPU the remaining syncpts of a partially executed job. + * + * CDMA will continue execution starting with the next job or will get + * into idle state. + */ + if (next_job) + restart_addr = next_job->first_get; + else + restart_addr = cdma->last_pos; + + if (!job) + goto resume; + + /* do CPU increments for the remaining syncpts */ + if (job->syncpt_recovery) { + dev_dbg(dev, "%s: perform CPU incr on pending buffers\n", + __func__); + + /* 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); + + dev_dbg(dev, "%s: finished sync_queue modification\n", + __func__); + } else { + struct host1x_job *failed_job = job; + + host1x_job_dump(dev, job); + + host1x_syncpt_set_locked(job->syncpt); + failed_job->cancelled = true; + + list_for_each_entry_continue(job, &cdma->sync_queue, list) { + unsigned int i; + + if (job->syncpt != failed_job->syncpt) + continue; + + for (i = 0; i < job->num_slots; i++) { + unsigned int slot = (job->first_get/8 + i) % + HOST1X_PUSHBUFFER_SLOTS; + u32 *mapped = cdma->push_buffer.mapped; + + /* + * Overwrite opcodes with 0 word writes + * to offset 0xbad. This does nothing but + * has a easily detected signature in debug + * traces. + * + * On systems with MLOCK enforcement enabled, + * the above 0 word writes would fall foul of + * the enforcement. As such, in the first slot + * put a RESTART_W opcode to the beginning + * of the next job. We don't use this for older + * chips since those only support the RESTART + * opcode with inconvenient alignment requirements. + */ + if (i == 0 && host1x->info->has_wide_gather) { + unsigned int next_job = (job->first_get/8 + job->num_slots) + % HOST1X_PUSHBUFFER_SLOTS; + mapped[2*slot+0] = (0xd << 28) | (next_job * 2); + mapped[2*slot+1] = 0x0; + } else { + mapped[2*slot+0] = 0x1bad0000; + mapped[2*slot+1] = 0x1bad0000; + } + } + + job->cancelled = true; + } + + wmb(); + + update_cdma_locked(cdma); + } + +resume: + /* roll back DMAGET and start up channel again */ + host1x_hw_cdma_resume(host1x, cdma, restart_addr); +} + +static void cdma_update_work(struct work_struct *work) +{ + struct host1x_cdma *cdma = container_of(work, struct host1x_cdma, update_work); + + mutex_lock(&cdma->lock); + update_cdma_locked(cdma); + mutex_unlock(&cdma->lock); +} + +/* + * Create a cdma + */ +int host1x_cdma_init(struct host1x_cdma *cdma) +{ + int err; + + mutex_init(&cdma->lock); + init_completion(&cdma->complete); + INIT_WORK(&cdma->update_work, cdma_update_work); + + 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); + + /* + * Check if syncpoint was locked due to previous job timeout. + * This needs to be done within the cdma lock to avoid a race + * with the timeout handler. + */ + if (job->syncpt->locked) { + mutex_unlock(&cdma->lock); + return -EPERM; + } + + 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); + 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); +} + +/* + * Push four words into two consecutive push buffer slots. Note that extra + * care needs to be taken not to split the two slots across the end of the + * push buffer. Otherwise the RESTART opcode at the end of the push buffer + * that ensures processing will restart at the beginning will break up the + * four words. + * + * Blocks as necessary if the push buffer is full. + */ +void host1x_cdma_push_wide(struct host1x_cdma *cdma, u32 op1, u32 op2, + u32 op3, u32 op4) +{ + struct host1x_channel *channel = cdma_to_channel(cdma); + struct host1x *host1x = cdma_to_host1x(cdma); + struct push_buffer *pb = &cdma->push_buffer; + unsigned int space = cdma->slots_free; + unsigned int needed = 2, extra = 0; + + if (host1x_debug_trace_cmdbuf) + trace_host1x_cdma_push_wide(dev_name(channel->dev), op1, op2, + op3, op4); + + /* compute number of extra slots needed for padding */ + if (pb->pos + 16 > pb->size) { + extra = (pb->size - pb->pos) / 8; + needed += extra; + } + + host1x_cdma_wait_pushbuffer_space(host1x, cdma, needed); + space = host1x_pushbuffer_space(pb); + + cdma->slots_free = space - needed; + cdma->slots_used += needed; + + if (extra > 0) { + /* + * If there isn't enough space at the tail of the pushbuffer, + * insert a RESTART(0) here to go back to the beginning. + * The code above adjusted the indexes appropriately. + */ + host1x_pushbuffer_push(pb, (0x5 << 28), 0xdead0000); + } + + host1x_pushbuffer_push(pb, op1, op2); + host1x_pushbuffer_push(pb, op3, op4); +} + +/* + * 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) +{ + schedule_work(&cdma->update_work); +} |