[PATCH] ARM: mx3/pcm037: properly allocate memory for mx3-camera

[Uwe Kleine-König]

There is no need to memzero the buffer because dma_alloc_coherent zeros
the memory for us.

This fixes:

	BUG: Your driver calls ioremap() on system memory.  This leads
	<4>to architecturally unpredictable behaviour on ARMv6+, and ioremap()
	<4>will fail in the next kernel release.  Please fix your driver.

Tested-by: Michael Grzeschik <mgr at pengutronix.de>
Signed-off-by: Uwe Kleine-König <u.kleine-koenig at pengutronix.de>
---
Hello,

it seems to work this way, still I'd like to have some feedback if this
is done right.  Russell?

I assume sending a patch to remove the <4> is just a waste of time,
isn't it?

Best regards
Uwe

 arch/arm/mach-mx3/mach-pcm037.c |   36 ++++++++++++++++++++----------------
 1 files changed, 20 insertions(+), 16 deletions(-)

diff --git a/arch/arm/mach-mx3/mach-pcm037.c b/arch/arm/mach-mx3/mach-pcm037.c
index 2ff3f66..265757f 100644
--- a/arch/arm/mach-mx3/mach-pcm037.c
+++ b/arch/arm/mach-mx3/mach-pcm037.c
@@ -32,6 +32,7 @@
 #include <linux/usb/otg.h>
 #include <linux/usb/ulpi.h>
 #include <linux/gfp.h>
+#include <linux/memblock.h>
 
 #include <media/soc_camera.h>
 
@@ -413,29 +414,22 @@ struct mx3_camera_pdata camera_pdata = {
 	.mclk_10khz	= 2000,
 };
 
+static phys_addr_t mx3_camera_base __initdata;
+#define MX3_CAMERA_BUF_SIZE SZ_4M
+
 static int __init pcm037_camera_alloc_dma(const size_t buf_size)
 {
-	dma_addr_t dma_handle;
-	void *buf;
 	int dma;
 
-	if (buf_size < 2 * 1024 * 1024)
-		return -EINVAL;
-
-	buf = dma_alloc_coherent(NULL, buf_size, &dma_handle, GFP_KERNEL);
-	if (!buf) {
-		pr_err("%s: cannot allocate camera buffer-memory\n", __func__);
-		return -ENOMEM;
-	}
-
-	memset(buf, 0, buf_size);
-
 	dma = dma_declare_coherent_memory(&mx3_camera.dev,
-					dma_handle, dma_handle, buf_size,
+					mx3_camera_base, mx3_camera_base,
+					MX3_CAMERA_BUF_SIZE,
 					DMA_MEMORY_MAP | DMA_MEMORY_EXCLUSIVE);
 
-	/* The way we call dma_declare_coherent_memory only a malloc can fail */
-	return dma & DMA_MEMORY_MAP ? 0 : -ENOMEM;
+	if (!(dma & DMA_MEMORY_MAP))
+		return -ENOMEM;
+
+	return 0;
 }
 
 static struct platform_device *devices[] __initdata = {
@@ -676,6 +670,15 @@ struct sys_timer pcm037_timer = {
 	.init	= pcm037_timer_init,
 };
 
+static void __init pcm037_reserve(void)
+{
+	/* reserve 4 MiB for mx3-camera */
+	mx3_camera_base = memblock_alloc(MX3_CAMERA_BUF_SIZE,
+			/* ??? */ MX3_CAMERA_BUF_SIZE);
+	memblock_free(mx3_camera_base, MX3_CAMERA_BUF_SIZE);
+	memblock_remove(mx3_camera_base, MX3_CAMERA_BUF_SIZE);
+}
+
 MACHINE_START(PCM037, "Phytec Phycore pcm037")
 	/* Maintainer: Pengutronix */
 	.boot_params    = MX3x_PHYS_OFFSET + 0x100,
@@ -683,4 +686,5 @@ MACHINE_START(PCM037, "Phytec Phycore pcm037")
 	.init_irq       = mx31_init_irq,
 	.init_machine   = mxc_board_init,
 	.timer          = &pcm037_timer,
+	.reserve	= pcm037_reserve,
 MACHINE_END
-- 
1.7.2.3