clear-pkgs-linux-iot-lts2018/1116-dma-buf-hyper_dmabuf-disable-remote-sync-by-default.patch

From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Dongwon Kim <dongwon.kim@intel.com>
Date: Mon, 17 Jun 2019 23:36:58 -0700
Subject: [PATCH] dma-buf/hyper_dmabuf: disable remote-sync by default

disable remote-sync by defining 'NO_DMA_BUF_SYNC'. This means all dmabuf
operations other than 'release' won't be notified to the exporter for
tracking. This was done to prevent possible performance degradation that
can be caused by excessive message exchange between importer and exporter.

Signed-off-by: Dongwon Kim <dongwon.kim@intel.com>
---
 .../dma-buf/hyper_dmabuf/hyper_dmabuf_ops.c   | 47 ++++++++++++++-----
 1 file changed, 34 insertions(+), 13 deletions(-)

diff --git a/drivers/dma-buf/hyper_dmabuf/hyper_dmabuf_ops.c b/drivers/dma-buf/hyper_dmabuf/hyper_dmabuf_ops.c
index 5d42bc487559..5c7101ecc742 100644
--- a/drivers/dma-buf/hyper_dmabuf/hyper_dmabuf_ops.c
+++ b/drivers/dma-buf/hyper_dmabuf/hyper_dmabuf_ops.c
@@ -41,6 +41,7 @@
 
 #define WAIT_AFTER_SYNC_REQ 0
 #define REFS_PER_PAGE (PAGE_SIZE/sizeof(grant_ref_t))
+#define NO_DMA_BUF_SYNC
 
 int dmabuf_refcount(struct dma_buf *dma_buf)
 {
@@ -93,15 +94,16 @@ static int hyper_dmabuf_ops_attach(struct dma_buf *dmabuf,
 				   struct dma_buf_attachment *attach)
 {
 	struct imported_sgt_info *imported;
-	int ret;
+	int ret = 0;
 
 	if (!attach->dmabuf->priv)
 		return -EINVAL;
 
 	imported = (struct imported_sgt_info *)attach->dmabuf->priv;
 
+#ifndef NO_DMA_BUF_SYNC
 	ret = sync_request(imported->hid, HYPER_DMABUF_OPS_ATTACH, WAIT_AFTER_SYNC_REQ);
-
+#endif
 	return ret;
 }
 
@@ -115,7 +117,9 @@ static void hyper_dmabuf_ops_detach(struct dma_buf *dmabuf,
 
 	imported = (struct imported_sgt_info *)attach->dmabuf->priv;
 
+#ifndef NO_DMA_BUF_SYNC
 	sync_request(imported->hid, HYPER_DMABUF_OPS_DETACH, WAIT_AFTER_SYNC_REQ);
+#endif
 }
 
 static struct sg_table *hyper_dmabuf_ops_map(
@@ -125,7 +129,6 @@ static struct sg_table *hyper_dmabuf_ops_map(
 	struct sg_table *st;
 	struct imported_sgt_info *imported;
 	struct pages_info *pg_info;
-	int ret;
 
 	if (!attachment->dmabuf->priv)
 		return NULL;
@@ -155,8 +158,9 @@ static struct sg_table *hyper_dmabuf_ops_map(
 	if (!dma_map_sg(attachment->dev, st->sgl, st->nents, dir))
 		goto err_free_sg;
 
-	ret = sync_request(imported->hid, HYPER_DMABUF_OPS_MAP, WAIT_AFTER_SYNC_REQ);
-
+#ifndef NO_DMA_BUF_SYNC
+	sync_request(imported->hid, HYPER_DMABUF_OPS_MAP, WAIT_AFTER_SYNC_REQ);
+#endif
 	kfree(pg_info->pgs);
 	kfree(pg_info);
 
@@ -193,7 +197,9 @@ static void hyper_dmabuf_ops_unmap(struct dma_buf_attachment *attachment,
 	sg_free_table(sg);
 	kfree(sg);
 
+#ifndef NO_DMA_BUF_SYNC
 	sync_request(imported->hid, HYPER_DMABUF_OPS_UNMAP, WAIT_AFTER_SYNC_REQ);
+#endif
 }
 
 static void hyper_dmabuf_ops_release(struct dma_buf *dma_buf)
@@ -273,15 +279,16 @@ static int hyper_dmabuf_ops_begin_cpu_access(struct dma_buf *dmabuf,
 					     enum dma_data_direction dir)
 {
 	struct imported_sgt_info *imported;
-	int ret;
+	int ret = 0;
 
 	if (!dmabuf->priv)
 		return -EINVAL;
 
 	imported = (struct imported_sgt_info *)dmabuf->priv;
 
+#ifndef NO_DMA_BUF_SYNC
 	ret = sync_request(imported->hid, HYPER_DMABUF_OPS_BEGIN_CPU_ACCESS, WAIT_AFTER_SYNC_REQ);
-
+#endif
 	return ret;
 }
 
@@ -289,13 +296,17 @@ static int hyper_dmabuf_ops_end_cpu_access(struct dma_buf *dmabuf,
 					   enum dma_data_direction dir)
 {
 	struct imported_sgt_info *imported;
+	int ret = 0;
 
 	if (!dmabuf->priv)
 		return -EINVAL;
 
 	imported = (struct imported_sgt_info *)dmabuf->priv;
 
-	return sync_request(imported->hid, HYPER_DMABUF_OPS_END_CPU_ACCESS, WAIT_AFTER_SYNC_REQ);
+#ifndef NO_DMA_BUF_SYNC
+	ret = sync_request(imported->hid, HYPER_DMABUF_OPS_END_CPU_ACCESS, WAIT_AFTER_SYNC_REQ);
+#endif
+	return ret;
 }
 
 #if LINUX_VERSION_CODE < KERNEL_VERSION(4, 17, 0)
@@ -309,8 +320,9 @@ static void *hyper_dmabuf_ops_kmap_atomic(struct dma_buf *dmabuf,
 
 	imported = (struct imported_sgt_info *)dmabuf->priv;
 
+#ifndef NO_DMA_BUF_SYNC
 	sync_request(imported->hid, HYPER_DMABUF_OPS_KMAP_ATOMIC);
-
+#endif
 	/* TODO: NULL for now. Need to return the addr of mapped region */
 	return NULL;
 }
@@ -325,7 +337,9 @@ static void hyper_dmabuf_ops_kunmap_atomic(struct dma_buf *dmabuf,
 
 	imported = (struct imported_sgt_info *)dmabuf->priv;
 
+#ifndef NO_DMA_BUF_SYNC
 	sync_request(imported->hid, HYPER_DMABUF_OPS_KUNMAP_ATOMIC, WAIT_AFTER_SYNC_REQ);
+#endif
 }
 #endif
 
@@ -338,8 +352,9 @@ static void *hyper_dmabuf_ops_kmap(struct dma_buf *dmabuf, unsigned long pgnum)
 
 	imported = (struct imported_sgt_info *)dmabuf->priv;
 
+#ifndef NO_DMA_BUF_SYNC
 	sync_request(imported->hid, HYPER_DMABUF_OPS_KMAP, WAIT_AFTER_SYNC_REQ);
-
+#endif
 	/* for now NULL.. need to return the address of mapped region */
 	return NULL;
 }
@@ -354,22 +369,25 @@ static void hyper_dmabuf_ops_kunmap(struct dma_buf *dmabuf, unsigned long pgnum,
 
 	imported = (struct imported_sgt_info *)dmabuf->priv;
 
+#ifndef NO_DMA_BUF_SYNC
 	sync_request(imported->hid, HYPER_DMABUF_OPS_KUNMAP, WAIT_AFTER_SYNC_REQ);
+#endif
 }
 
 static int hyper_dmabuf_ops_mmap(struct dma_buf *dmabuf,
 				 struct vm_area_struct *vma)
 {
 	struct imported_sgt_info *imported;
-	int ret;
+	int ret = 0;
 
 	if (!dmabuf->priv)
 		return -EINVAL;
 
 	imported = (struct imported_sgt_info *)dmabuf->priv;
 
+#ifndef NO_DMA_BUF_SYNC
 	ret = sync_request(imported->hid, HYPER_DMABUF_OPS_MMAP, WAIT_AFTER_SYNC_REQ);
-
+#endif
 	return ret;
 }
 
@@ -382,8 +400,9 @@ static void *hyper_dmabuf_ops_vmap(struct dma_buf *dmabuf)
 
 	imported = (struct imported_sgt_info *)dmabuf->priv;
 
+#ifndef NO_DMA_BUF_SYNC
 	sync_request(imported->hid, HYPER_DMABUF_OPS_VMAP, WAIT_AFTER_SYNC_REQ);
-
+#endif
 	return NULL;
 }
 
@@ -396,7 +415,9 @@ static void hyper_dmabuf_ops_vunmap(struct dma_buf *dmabuf, void *vaddr)
 
 	imported = (struct imported_sgt_info *)dmabuf->priv;
 
+#ifndef NO_DMA_BUF_SYNC
 	sync_request(imported->hid, HYPER_DMABUF_OPS_VUNMAP, WAIT_AFTER_SYNC_REQ);
+#endif
 }
 
 static const struct dma_buf_ops hyper_dmabuf_ops = {
-- 
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