video: tegra: host: Simplify robustness

nvhost attempts to purge all buffers from timed out contexts. This is
very error prone, and not necessary. Change behavior so that only the
hung job, and the immediately following jobs from same context are
purged. This simplifies code, and corrects bug where the push buffer
modifications caused panics.

Bug 982946

Change-Id: Ifb26484cf02ef40f8d5b20338eebc0a731f453cf
Signed-off-by: Terje Bergstrom <tbergstrom@nvidia.com>
Reviewed-on: http://git-master/r/102234
Reviewed-by: Rohan Somvanshi <rsomvanshi@nvidia.com>
Tested-by: Rohan Somvanshi <rsomvanshi@nvidia.com>

4 files changed, 2 insertions, 183 deletions

diff --git a/drivers/video/tegra/host/chip_support.h b/drivers/video/tegra/host/chip_support.h
index c0d567df425a..edc5f6a51574 100644
--- a/drivers/video/tegra/host/chip_support.h
+++ b/drivers/video/tegra/host/chip_support.h
@@ -69,11 +69,6 @@ struct nvhost_chip_support {
 					 u32 syncpt_incrs,
 					 u32 syncval,
 					 u32 nr_slots);
-		void (*timeout_pb_incr)(struct nvhost_cdma *,
-					u32 getptr,
-					u32 syncpt_incrs,
-					u32 nr_slots,
-					bool exec_ctxsave);
 	} cdma;
 
 	struct {
diff --git a/drivers/video/tegra/host/host1x/host1x_cdma.c b/drivers/video/tegra/host/host1x/host1x_cdma.c
index 813b35476f5b..fcb1f05f0025 100644
--- a/drivers/video/tegra/host/host1x/host1x_cdma.c
+++ b/drivers/video/tegra/host/host1x/host1x_cdma.c
@@ -193,96 +193,25 @@ static u32 push_buffer_putptr(struct push_buffer *pb)
  */
 
 /**
- * Init timeout and syncpt incr buffer resources
+ * Init timeout resources
  */
 static int cdma_timeout_init(struct nvhost_cdma *cdma,
 				 u32 syncpt_id)
 {
-	struct nvhost_master *dev = cdma_to_dev(cdma);
-	struct nvmap_client *nvmap = cdma_to_nvmap(cdma);
-	struct syncpt_buffer *sb = &cdma->syncpt_buffer;
-	struct nvhost_channel *ch = cdma_to_channel(cdma);
-	u32 i = 0;
-
 	if (syncpt_id == NVSYNCPT_INVALID)
 		return -EINVAL;
 
-	/* allocate and map syncpt incr memory */
-	sb->mem = nvmap_alloc(nvmap,
-			(SYNCPT_INCR_BUFFER_SIZE_WORDS * sizeof(u32)), 32,
-			NVMAP_HANDLE_WRITE_COMBINE, 0);
-	if (IS_ERR_OR_NULL(sb->mem)) {
-		sb->mem = NULL;
-		goto fail;
-	}
-	sb->mapped = nvmap_mmap(sb->mem);
-	if (sb->mapped == NULL)
-		goto fail;
-
-	/* pin syncpt buffer and get physical address */
-	sb->phys = nvmap_pin(nvmap, sb->mem);
-	if (sb->phys >= 0xfffff000) {
-		sb->phys = 0;
-		goto fail;
-	}
-
-	dev_dbg(&dev->dev->dev, "%s: SYNCPT_INCR buffer at 0x%x\n",
-		 __func__, sb->phys);
-
-	sb->words_per_incr = (syncpt_id == NVSYNCPT_3D) ? 5 : 3;
-	sb->incr_per_buffer = (SYNCPT_INCR_BUFFER_SIZE_WORDS /
-				sb->words_per_incr);
-
-	/* init buffer with SETCL and INCR_SYNCPT methods */
-	while (i < sb->incr_per_buffer) {
-		sb->mapped[i++] = nvhost_opcode_setclass(NV_HOST1X_CLASS_ID,
-						0, 0);
-		sb->mapped[i++] = nvhost_opcode_imm_incr_syncpt(
-						NV_SYNCPT_IMMEDIATE,
-						syncpt_id);
-		if (syncpt_id == NVSYNCPT_3D) {
-			/* also contains base increments */
-			sb->mapped[i++] = nvhost_opcode_nonincr(
-						NV_CLASS_HOST_INCR_SYNCPT_BASE,
-						1);
-			sb->mapped[i++] = nvhost_class_host_incr_syncpt_base(
-						NVWAITBASE_3D, 1);
-		}
-		sb->mapped[i++] = nvhost_opcode_setclass(ch->dev->class,
-						0, 0);
-	}
-	wmb();
-
 	INIT_DELAYED_WORK(&cdma->timeout.wq, cdma_timeout_handler);
 	cdma->timeout.initialized = true;
 
 	return 0;
-fail:
-	cdma_op().timeout_destroy(cdma);
-	return -ENOMEM;
 }
 
 /**
- * Clean up timeout syncpt buffer resources
+ * Clean up timeout resources
  */
 static void cdma_timeout_destroy(struct nvhost_cdma *cdma)
 {
-	struct nvmap_client *nvmap = cdma_to_nvmap(cdma);
-	struct syncpt_buffer *sb = &cdma->syncpt_buffer;
-
-	if (sb->mapped)
-		nvmap_munmap(sb->mem, sb->mapped);
-
-	if (sb->phys != 0)
-		nvmap_unpin(nvmap, sb->mem);
-
-	if (sb->mem)
-		nvmap_free(nvmap, sb->mem);
-
-	sb->mem = NULL;
-	sb->mapped = NULL;
-	sb->phys = 0;
-
 	if (cdma->timeout.initialized)
 		cancel_delayed_work(&cdma->timeout.wq);
 	cdma->timeout.initialized = false;
@@ -326,73 +255,6 @@ static void cdma_timeout_cpu_incr(struct nvhost_cdma *cdma, u32 getptr,
 }
 
 /**
- * This routine is called at the point we transition back into a timed
- * ctx. The syncpts are incremented via pushbuffer with a flag indicating
- * whether there's a CTXSAVE that should be still executed (for the
- * preceding HW ctx).
- */
-static void cdma_timeout_pb_incr(struct nvhost_cdma *cdma, u32 getptr,
-				u32 syncpt_incrs, u32 nr_slots,
-				bool exec_ctxsave)
-{
-	struct nvhost_master *dev = cdma_to_dev(cdma);
-	struct syncpt_buffer *sb = &cdma->syncpt_buffer;
-	struct push_buffer *pb = &cdma->push_buffer;
-	struct host1x_hwctx *hwctx = to_host1x_hwctx(cdma->timeout.ctx);
-	u32 getidx, *p;
-
-	/* should have enough slots to incr to desired count */
-	BUG_ON(syncpt_incrs > (nr_slots * sb->incr_per_buffer));
-
-	getidx = getptr - pb->phys;
-	if (exec_ctxsave) {
-		/* don't disrupt the CTXSAVE of a good/non-timed out ctx */
-		nr_slots -= hwctx->save_slots;
-		syncpt_incrs -= hwctx->save_incrs;
-
-		getidx += (hwctx->save_slots * 8);
-		getidx &= (PUSH_BUFFER_SIZE - 1);
-
-		dev_dbg(&dev->dev->dev,
-			"%s: exec CTXSAVE of prev ctx (slots %d, incrs %d)\n",
-			__func__, nr_slots, syncpt_incrs);
-	}
-
-	while (syncpt_incrs) {
-		u32 incrs, count;
-
-		/* GATHER count are incrs * number of DWORDs per incr */
-		incrs = min(syncpt_incrs, sb->incr_per_buffer);
-		count = incrs * sb->words_per_incr;
-
-		p = (u32 *)((u32)pb->mapped + getidx);
-		*(p++) = nvhost_opcode_gather(count);
-		*(p++) = sb->phys;
-
-		dev_dbg(&dev->dev->dev,
-			"%s: GATHER at 0x%x, from 0x%x, dcount = %d\n",
-			__func__,
-			pb->phys + getidx, sb->phys,
-			(incrs * sb->words_per_incr));
-
-		syncpt_incrs -= incrs;
-		getidx = (getidx + 8) & (PUSH_BUFFER_SIZE - 1);
-		nr_slots--;
-	}
-
-	/* NOP remaining slots */
-	while (nr_slots--) {
-		p = (u32 *)((u32)pb->mapped + getidx);
-		*(p++) = NVHOST_OPCODE_NOOP;
-		*(p++) = NVHOST_OPCODE_NOOP;
-		dev_dbg(&dev->dev->dev, "%s: NOP at 0x%x\n",
-			__func__, pb->phys + getidx);
-		getidx = (getidx + 8) & (PUSH_BUFFER_SIZE - 1);
-	}
-	wmb();
-}
-
-/**
  * Start channel DMA
  */
 static void cdma_start(struct nvhost_cdma *cdma)
@@ -653,7 +515,6 @@ int host1x_init_cdma_support(struct nvhost_chip_support *op)
 	op->cdma.timeout_teardown_begin = cdma_timeout_teardown_begin;
 	op->cdma.timeout_teardown_end = cdma_timeout_teardown_end;
 	op->cdma.timeout_cpu_incr = cdma_timeout_cpu_incr;
-	op->cdma.timeout_pb_incr = cdma_timeout_pb_incr;
 
 	op->push_buffer.reset = push_buffer_reset;
 	op->push_buffer.init = push_buffer_init;
diff --git a/drivers/video/tegra/host/nvhost_cdma.c b/drivers/video/tegra/host/nvhost_cdma.c
index 4229def79c1e..4fcd6f3d3c03 100644
--- a/drivers/video/tegra/host/nvhost_cdma.c
+++ b/drivers/video/tegra/host/nvhost_cdma.c
@@ -213,7 +213,6 @@ void nvhost_cdma_update_sync_queue(struct nvhost_cdma *cdma,
 {
 	u32 get_restart;
 	u32 syncpt_incrs;
-	bool exec_ctxsave;
 	struct nvhost_job *job = NULL;
 	u32 syncpt_val;
 
@@ -290,41 +289,6 @@ void nvhost_cdma_update_sync_queue(struct nvhost_cdma *cdma,
 	}
 
 	dev_dbg(dev,
-		"%s: GPU incr blocked interleaved ctx buffers\n",
-		__func__);
-
-	exec_ctxsave = false;
-
-	/* setup GPU increments */
-	list_for_each_entry_from(job, &cdma->sync_queue, list) {
-		/* same context, increment in the pushbuffer */
-		if (job->clientid == cdma->timeout.clientid) {
-			/* won't need a timeout when replayed */
-			job->timeout = 0;
-
-			/* update buffer's syncpts in the pushbuffer */
-			cdma_op().timeout_pb_incr(cdma,
-					job->first_get,
-					job->syncpt_incrs,
-					job->num_slots,
-					exec_ctxsave);
-
-			exec_ctxsave = false;
-		} else {
-			dev_dbg(dev,
-				"%s: switch to a different userctx\n",
-				__func__);
-			/*
-			 * If previous context was the timed out context
-			 * then clear its CTXSAVE in this slot.
-			 */
-			exec_ctxsave = true;
-		}
-
-		nvhost_job_dump(dev, job);
-	}
-
-	dev_dbg(dev,
 		"%s: finished sync_queue modification\n", __func__);
 
 	/* roll back DMAGET and start up channel again */
diff --git a/drivers/video/tegra/host/nvhost_cdma.h b/drivers/video/tegra/host/nvhost_cdma.h
index 2f83d07be9d1..b947afe18c32 100644
--- a/drivers/video/tegra/host/nvhost_cdma.h
+++ b/drivers/video/tegra/host/nvhost_cdma.h
@@ -95,7 +95,6 @@ struct nvhost_cdma {
 	unsigned int first_get;		/* DMAGET value, where submit begins */
 	unsigned int last_put;		/* last value written to DMAPUT */
 	struct push_buffer push_buffer;	/* channel's push buffer */
-	struct syncpt_buffer syncpt_buffer; /* syncpt incr buffer */
 	struct list_head sync_queue;	/* job queue */
 	struct buffer_timeout timeout;	/* channel's timeout state/wq */
 	bool running;