ARM: Add arm_memblock_steal() to allocate memory away from the kernel
Several platforms are now using the memblock_alloc+memblock_free+
memblock_remove trick to obtain memory which won't be mapped in the
kernel's page tables. Most platforms do this (correctly) in the
->reserve callback. However, OMAP has started to call these functions
outside of this callback, and this is extremely unsafe - memory will
not be unmapped, and could well be given out after memblock is no
longer responsible for its management.
So, provide arm_memblock_steal() to perform this function, and ensure
that it panic()s if it is used inappropriately. Convert everyone
over, including OMAP.
As a result, OMAP with OMAP4_ERRATA_I688 enabled will panic on boot
with this change. Mark this option as BROKEN and make it depend on
BROKEN. OMAP needs to be fixed, or 137d105d50 (ARM: OMAP4: Fix
errata i688 with MPU interconnect barriers.) reverted until such
time it can be fixed correctly.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
diff --git a/arch/arm/mach-imx/mach-pcm037.c b/arch/arm/mach-imx/mach-pcm037.c
index d7e1516..e48854b 100644
--- a/arch/arm/mach-imx/mach-pcm037.c
+++ b/arch/arm/mach-imx/mach-pcm037.c
@@ -39,6 +39,7 @@
#include <asm/mach/arch.h>
#include <asm/mach/time.h>
#include <asm/mach/map.h>
+#include <asm/memblock.h>
#include <mach/common.h>
#include <mach/hardware.h>
#include <mach/iomux-mx3.h>
@@ -680,10 +681,8 @@
static void __init pcm037_reserve(void)
{
/* reserve 4 MiB for mx3-camera */
- mx3_camera_base = memblock_alloc(MX3_CAMERA_BUF_SIZE,
+ mx3_camera_base = arm_memblock_steal(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")