android-5.4/ANDROID-dma-buf-Add-support-to-get-flags-associated-with-a-buffer.patch

From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: "Isaac J. Manjarres" <isaacm@codeaurora.org>
Date: Wed, 19 Jun 2019 15:37:12 -0700
Subject: ANDROID: dma-buf: Add support to get flags associated with a buffer

Allow kernel clients to get the flags associated with a buffer
that is wrapped by a dma-buf. This information can be used to
communicate the type of memory associated with the
buffer(e.g. uncached vs cached memory).

Bug: 133508579
Test: ion-unit-tests
Change-Id: I82eab8beb738b258616c22a01080615d7ffb6ad5
Signed-off-by: Isaac J. Manjarres <isaacm@codeaurora.org>
Signed-off-by: Sandeep Patil <sspatil@google.com>
---
 drivers/dma-buf/dma-buf.c | 14 ++++++++++++++
 include/linux/dma-buf.h   | 15 +++++++++++++++
 2 files changed, 29 insertions(+)

diff --git a/drivers/dma-buf/dma-buf.c b/drivers/dma-buf/dma-buf.c
index 532a854be1b3..59f6a39120fd 100644
--- a/drivers/dma-buf/dma-buf.c
+++ b/drivers/dma-buf/dma-buf.c
@@ -1188,6 +1188,20 @@ void dma_buf_vunmap(struct dma_buf *dmabuf, void *vaddr)
 }
 EXPORT_SYMBOL_GPL(dma_buf_vunmap);
 
+int dma_buf_get_flags(struct dma_buf *dmabuf, unsigned long *flags)
+{
+	int ret = 0;
+
+	if (WARN_ON(!dmabuf) || !flags)
+		return -EINVAL;
+
+	if (dmabuf->ops->get_flags)
+		ret = dmabuf->ops->get_flags(dmabuf, flags);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(dma_buf_get_flags);
+
 #ifdef CONFIG_DEBUG_FS
 static int dma_buf_debug_show(struct seq_file *s, void *unused)
 {
diff --git a/include/linux/dma-buf.h b/include/linux/dma-buf.h
index 0458da673ec5..f26b4a8212d0 100644
--- a/include/linux/dma-buf.h
+++ b/include/linux/dma-buf.h
@@ -318,6 +318,20 @@ struct dma_buf_ops {
 
 	void *(*vmap)(struct dma_buf *);
 	void (*vunmap)(struct dma_buf *, void *vaddr);
+
+	/**
+	 * @get_flags:
+	 *
+	 * This is called by dma_buf_get_flags and is used to get the buffer's
+	 * flags.
+	 * This callback is optional.
+	 *
+	 * Returns:
+	 *
+	 * 0 on success or a negative error code on failure. On success flags
+	 * will be populated with the buffer's flags.
+	 */
+	int (*get_flags)(struct dma_buf *dmabuf, unsigned long *flags);
 };
 
 /**
@@ -486,4 +500,5 @@ int dma_buf_mmap(struct dma_buf *, struct vm_area_struct *,
 		 unsigned long);
 void *dma_buf_vmap(struct dma_buf *);
 void dma_buf_vunmap(struct dma_buf *, void *vaddr);
+int dma_buf_get_flags(struct dma_buf *dmabuf, unsigned long *flags);
 #endif /* __DMA_BUF_H__ */