[PATCH v2] kfifo: don't include dma-mapping.h in kfifo.h

[Christoph Hellwig <hch@lst.de>]

Nothing in kfifo.h directly needs dma-mapping.h, only two macros
use DMA_MAPPING_ERROR when actually instantiated.  Drop the
dma-mapping.h include to reduce include bloat.

Add an explicity <linux/io.h> include to drivers/mailbox/omap-mailbox.c
as that file uses __raw_readl and __raw_writel through a complicated
include chain involving <linux/dma-mapping.h>

Fixes: d52b761e4b1a ("kfifo: add kfifo_dma_out_prepare_mapped()")
Signed-off-by: Christoph Hellwig <hch@lst.de>
---

Changes since v1:
 - improve the commit log

 drivers/mailbox/omap-mailbox.c | 1 +
 include/linux/kfifo.h          | 1 -
 samples/kfifo/dma-example.c    | 1 +
 3 files changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/mailbox/omap-mailbox.c b/drivers/mailbox/omap-mailbox.c
index 6797770474a5..680243751d62 100644
--- a/drivers/mailbox/omap-mailbox.c
+++ b/drivers/mailbox/omap-mailbox.c
@@ -15,6 +15,7 @@
 #include <linux/slab.h>
 #include <linux/kfifo.h>
 #include <linux/err.h>
+#include <linux/io.h>
 #include <linux/module.h>
 #include <linux/of.h>
 #include <linux/platform_device.h>
diff --git a/include/linux/kfifo.h b/include/linux/kfifo.h
index 564868bdce89..fd743d4c4b4b 100644
--- a/include/linux/kfifo.h
+++ b/include/linux/kfifo.h
@@ -37,7 +37,6 @@
  */
 
 #include <linux/array_size.h>
-#include <linux/dma-mapping.h>
 #include <linux/spinlock.h>
 #include <linux/stddef.h>
 #include <linux/types.h>
diff --git a/samples/kfifo/dma-example.c b/samples/kfifo/dma-example.c
index 48df719dac8c..8076ac410161 100644
--- a/samples/kfifo/dma-example.c
+++ b/samples/kfifo/dma-example.c
@@ -9,6 +9,7 @@
 #include <linux/kfifo.h>
 #include <linux/module.h>
 #include <linux/scatterlist.h>
+#include <linux/dma-mapping.h>
 
 /*
  * This module shows how to handle fifo dma operations.
-- 
2.45.2