// 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); 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) { 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 = 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 *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; 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; /* do CPU increments for the remaining syncpts */ if (job) { 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__); } /* 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); init_completion(&cdma->complete); 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); } /* * 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 needed = 2, extra = 0, i; unsigned int space = cdma->slots_free; 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; /* * Note that we rely on the fact that this is only used to submit wide * gather opcodes, which consist of 3 words, and they are padded with * a NOP to avoid having to deal with fractional slots (a slot always * represents 2 words). The fourth opcode passed to this function will * therefore always be a NOP. * * This works around a slight ambiguity when it comes to opcodes. For * all current host1x incarnations the NOP opcode uses the exact same * encoding (0x20000000), so we could hard-code the value here, but a * new incarnation may change it and break that assumption. */ for (i = 0; i < extra; i++) host1x_pushbuffer_push(pb, op4, op4); 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) { mutex_lock(&cdma->lock); update_cdma_locked(cdma); mutex_unlock(&cdma->lock); }