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/plat-omap/devices.c b/arch/arm/plat-omap/devices.c
index 1971932..60278f4 100644
--- a/arch/arm/plat-omap/devices.c
+++ b/arch/arm/plat-omap/devices.c
@@ -20,6 +20,7 @@
#include <mach/hardware.h>
#include <asm/mach-types.h>
#include <asm/mach/map.h>
+#include <asm/memblock.h>
#include <plat/tc.h>
#include <plat/board.h>
@@ -164,14 +165,12 @@
if (!size)
return;
- paddr = memblock_alloc(size, SZ_1M);
+ paddr = arm_memblock_steal(size, SZ_1M);
if (!paddr) {
pr_err("%s: failed to reserve %x bytes\n",
__func__, size);
return;
}
- memblock_free(paddr, size);
- memblock_remove(paddr, size);
omap_dsp_phys_mempool_base = paddr;
}