nvhost: split hardware context state into refcounted object

Change-Id: I69bfed3522d7d2082530204d8f568458f2966638
Reviewed-on: http://git-master/r/5094
Reviewed-by: Andrew Howe <ahowe@nvidia.com>
Reviewed-by: Antti Hatala <ahatala@nvidia.com>
Tested-by: Antti Hatala <ahatala@nvidia.com>

5 files changed, 48 insertions, 52 deletions

diff --git a/drivers/video/tegra/host/nvhost_3dctx.c b/drivers/video/tegra/host/nvhost_3dctx.c
index c7c4c30ac9d3..57e39ce9d319 100644
--- a/drivers/video/tegra/host/nvhost_3dctx.c
+++ b/drivers/video/tegra/host/nvhost_3dctx.c
@@ -399,15 +399,21 @@ static void __init setup_save(
 
 /*** ctx3d ***/
 
-static int ctx3d_init(struct nvhost_hwctx *ctx)
+static struct nvhost_hwctx *ctx3d_alloc(struct nvhost_channel *ch)
 {
+	struct nvhost_hwctx *ctx;
+	ctx = kzalloc(sizeof(*ctx), GFP_KERNEL);
+	if (!ctx)
+		return NULL;
 	ctx->restore = nvmap_alloc(context_restore_size * 4, 32,
 				NVMEM_HANDLE_WRITE_COMBINE,
 				(void**)&ctx->save_cpu_data);
-	if (IS_ERR_OR_NULL(ctx->restore))
-		return PTR_ERR(ctx->restore);
-
+	if (IS_ERR_OR_NULL(ctx->restore)) {
+		kfree(ctx);
+		return NULL;
+	}
 	setup_restore(ctx->save_cpu_data, NVWAITBASE_3D);
+	ctx->channel = ch;
 	ctx->restore_phys = nvmap_pin_single(ctx->restore);
 	ctx->restore_size = context_restore_size;
 	ctx->save = context_save_buf;
@@ -416,12 +422,25 @@ static int ctx3d_init(struct nvhost_hwctx *ctx)
 	ctx->save_incrs = 3;
 	ctx->restore_incrs = 1;
 	ctx->valid = false;
-	return 0;
+	kref_init(&ctx->ref);
+	return ctx;
 }
 
-static void ctx3d_deinit(struct nvhost_hwctx *ctx)
+static void ctx3d_free(struct kref *ref)
 {
+	struct nvhost_hwctx *ctx = container_of(ref, struct nvhost_hwctx, ref);
 	nvmap_free(ctx->restore, ctx->save_cpu_data);
+	kfree(ctx);
+}
+
+static void ctx3d_get(struct nvhost_hwctx *ctx)
+{
+	kref_get(&ctx->ref);
+}
+
+static void ctx3d_put(struct nvhost_hwctx *ctx)
+{
+	kref_put(&ctx->ref, ctx3d_free);
 }
 
 static void ctx3d_save_service(struct nvhost_hwctx *ctx)
@@ -477,8 +496,9 @@ int __init nvhost_3dctx_handler_init(struct nvhost_hwctx_handler *h)
 	context_save_phys = nvmap_pin_single(context_save_buf);
 	setup_save(context_save_ptr, NULL, NULL, NVSYNCPT_3D, NVWAITBASE_3D);
 
-	h->init = ctx3d_init;
-	h->deinit = ctx3d_deinit;
+	h->alloc = ctx3d_alloc;
+	h->get = ctx3d_get;
+	h->put = ctx3d_put;
 	h->save_service = ctx3d_save_service;
 	return 0;
 }
diff --git a/drivers/video/tegra/host/nvhost_channel.c b/drivers/video/tegra/host/nvhost_channel.c
index 7215e597699b..f75ee292b57a 100644
--- a/drivers/video/tegra/host/nvhost_channel.c
+++ b/drivers/video/tegra/host/nvhost_channel.c
@@ -74,8 +74,8 @@ static const struct nvhost_channeldesc channelmap[] = {
 	/* channel 4 */
 	.name	       = "vi",
 	.syncpts       = BIT(NVSYNCPT_VI_ISP_0) | BIT(NVSYNCPT_VI_ISP_1) |
-		         BIT(NVSYNCPT_VI_ISP_2) | BIT(NVSYNCPT_VI_ISP_3) |
-		         BIT(NVSYNCPT_VI_ISP_4) | BIT(NVSYNCPT_VI_ISP_5),
+			 BIT(NVSYNCPT_VI_ISP_2) | BIT(NVSYNCPT_VI_ISP_3) |
+			 BIT(NVSYNCPT_VI_ISP_4) | BIT(NVSYNCPT_VI_ISP_5),
 	.modulemutexes = BIT(NVMODMUTEX_VI),
 	.exclusive     = true,
 },
@@ -228,11 +228,10 @@ static void power_3d(struct nvhost_module *mod, enum nvhost_power_action action)
 			save.op2 = ch->cur_ctx->save_phys;
 			ctxsw.intr_data = ch->cur_ctx;
 			ctxsw.syncpt_val = syncval - 1;
-			nvhost_channel_submit(ch, &save, 1, &ctxsw, 1, NULL, 0, NVSYNCPT_3D, syncval);
-			ch->cur_ctx->last_access_id = NVSYNCPT_3D;
-			ch->cur_ctx->last_access_value = syncval;
 			ch->cur_ctx->valid = true;
+			ch->ctxhandler.get(ch->cur_ctx);
 			ch->cur_ctx = NULL;
+			nvhost_channel_submit(ch, &save, 1, &ctxsw, 1, NULL, 0, NVSYNCPT_3D, syncval);
 			nvhost_intr_add_action(&ch->dev->intr, NVSYNCPT_3D, syncval,
 					NVHOST_INTR_ACTION_WAKEUP, &wq, NULL);
 			wait_event(wq, nvhost_syncpt_min_cmp(&ch->dev->syncpt, NVSYNCPT_3D, syncval));
diff --git a/drivers/video/tegra/host/nvhost_dev.c b/drivers/video/tegra/host/nvhost_dev.c
index 6a5dbcec58ea..b74e140d278e 100644
--- a/drivers/video/tegra/host/nvhost_dev.c
+++ b/drivers/video/tegra/host/nvhost_dev.c
@@ -53,7 +53,6 @@ struct nvhost_channel_userctx {
 	int pinarray_size;
 	struct nvmap_pinarray_elem pinarray[NVHOST_MAX_HANDLES];
 	struct nvmap_handle *unpinarray[NVHOST_MAX_HANDLES];
-	/* hw context (if needed) */
 };
 
 struct nvhost_ctrl_userctx {
@@ -67,13 +66,8 @@ static int nvhost_channelrelease(struct inode *inode, struct file *filp)
 	filp->private_data = NULL;
 
 	nvhost_putchannel(priv->ch, priv->hwctx);
-	if (priv->hwctx) {
-		if (priv->hwctx->valid)
-			nvhost_syncpt_wait(&priv->ch->dev->syncpt,
-					priv->hwctx->last_access_id,
-					priv->hwctx->last_access_value);
-		priv->ch->ctxhandler.deinit(priv->hwctx);
-	}
+	if (priv->hwctx)
+		priv->ch->ctxhandler.put(priv->hwctx);
 	if (priv->gather_mem)
 		nvmap_free(priv->gather_mem, priv->gathers);
 	if (priv->nvmapctx)
@@ -86,20 +80,13 @@ static int nvhost_channelopen(struct inode *inode, struct file *filp)
 {
 	struct nvhost_channel_userctx *priv;
 	struct nvhost_channel *ch;
-	size_t hwctx_mem = 0;
-	size_t alloc_size = 0;
 
 	ch = container_of(inode->i_cdev, struct nvhost_channel, cdev);
 	ch = nvhost_getchannel(ch);
 	if (IS_ERR(ch))
 		return PTR_ERR(ch);
 
-	alloc_size += sizeof(*priv);
-	if (ch->ctxhandler.init) {
-		hwctx_mem = alloc_size;
-		alloc_size += sizeof(struct nvhost_hwctx);
-	}
-	priv = kzalloc(alloc_size, GFP_KERNEL);
+	priv = kzalloc(sizeof(*priv), GFP_KERNEL);
 	if (!priv) {
 		nvhost_putchannel(ch, NULL);
 		return -ENOMEM;
@@ -111,13 +98,10 @@ static int nvhost_channelopen(struct inode *inode, struct file *filp)
 		NVMEM_HANDLE_CACHEABLE, (void**)&priv->gathers);
 	if (IS_ERR_OR_NULL(priv->gather_mem))
 		goto fail;
-	if (ch->ctxhandler.init) {
-		priv->hwctx = (struct nvhost_hwctx *)(((u8*)priv) + hwctx_mem);
-		priv->hwctx->channel = ch;
-		if (ch->ctxhandler.init(priv->hwctx) < 0) {
-			priv->hwctx = NULL;
+	if (ch->ctxhandler.alloc) {
+		priv->hwctx = ch->ctxhandler.alloc(ch);
+		if (!priv->hwctx)
 			goto fail;
-		}
 	}
 
 	return 0;
@@ -275,7 +259,10 @@ static int nvhost_ioctl_channel_flush(
 			num_intrs = 1;
 			ctxsw.syncpt_val = hw->save_incrs - 1;
 			ctxsw.intr_data = hw;
+			hw->valid = true;
+			ctx->ch->ctxhandler.get(hw);
 		}
+		ctx->ch->cur_ctx = ctx->hwctx;
 	}
 
 	/* add a setclass for modules that require it */
@@ -305,19 +292,6 @@ static int nvhost_ioctl_channel_flush(
 	nvhost_intr_add_action(&ctx->ch->dev->intr, ctx->syncpt_id, syncval,
 			NVHOST_INTR_ACTION_SUBMIT_COMPLETE, ctx->ch, NULL);
 
-	/* update current context */
-	if (ctx->ch->cur_ctx != ctx->hwctx) {
-		struct nvhost_hwctx *hw = ctx->ch->cur_ctx;
-		if (hw) {
-			hw->last_access_id = ctx->syncpt_id;
-			hw->last_access_value = syncval;
-			hw->valid = true;
-		}
-		hw = ctx->hwctx;
-		hw->last_access_id = ctx->syncpt_id;
-		hw->last_access_value = syncval;
-		ctx->ch->cur_ctx = hw;
-	}
 	mutex_unlock(&ctx->ch->submitlock);
 	args->value = syncval;
 	return 0;
diff --git a/drivers/video/tegra/host/nvhost_hwctx.h b/drivers/video/tegra/host/nvhost_hwctx.h
index d1a8930e0ecb..86ed9f5ed3e8 100644
--- a/drivers/video/tegra/host/nvhost_hwctx.h
+++ b/drivers/video/tegra/host/nvhost_hwctx.h
@@ -26,13 +26,14 @@
 #include <linux/string.h>
 #include <linux/nvhost.h>
 #include <linux/nvmap.h>
+#include <linux/kref.h>
 
 struct nvhost_channel;
 
 struct nvhost_hwctx {
+	struct kref ref;
+
 	struct nvhost_channel *channel;
-	u32 last_access_id;
-	u32 last_access_value;
 	bool valid;
 
 	struct nvmap_handle *save;
@@ -48,8 +49,9 @@ struct nvhost_hwctx {
 };
 
 struct nvhost_hwctx_handler {
-	int (*init) (struct nvhost_hwctx *ctx);
-	void (*deinit) (struct nvhost_hwctx *ctx);
+	struct nvhost_hwctx * (*alloc) (struct nvhost_channel *ch);
+	void (*get) (struct nvhost_hwctx *ctx);
+	void (*put) (struct nvhost_hwctx *ctx);
 	void (*save_service) (struct nvhost_hwctx *ctx);
 };
 
diff --git a/drivers/video/tegra/host/nvhost_intr.c b/drivers/video/tegra/host/nvhost_intr.c
index 3d101b221b71..5b32b19c7a69 100644
--- a/drivers/video/tegra/host/nvhost_intr.c
+++ b/drivers/video/tegra/host/nvhost_intr.c
@@ -182,6 +182,7 @@ static void action_ctxsave(struct nvhost_waitlist *waiter)
 	struct nvhost_channel *channel = hwctx->channel;
 
 	channel->ctxhandler.save_service(hwctx);
+	channel->ctxhandler.put(hwctx);
 }
 
 static void action_wakeup(struct nvhost_waitlist *waiter)