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-omap2/omap4-common.c b/arch/arm/mach-omap2/omap4-common.c
index bc16c818c..40a8fbc 100644
--- a/arch/arm/mach-omap2/omap4-common.c
+++ b/arch/arm/mach-omap2/omap4-common.c
@@ -20,6 +20,7 @@
#include <asm/hardware/gic.h>
#include <asm/hardware/cache-l2x0.h>
#include <asm/mach/map.h>
+#include <asm/memblock.h>
#include <plat/irqs.h>
#include <plat/sram.h>
@@ -61,13 +62,8 @@
return -ENODEV;
size = ALIGN(PAGE_SIZE, SZ_1M);
- paddr = memblock_alloc(size, SZ_1M);
- if (!paddr) {
- pr_err("%s: failed to reserve 4 Kbytes\n", __func__);
- return -ENOMEM;
- }
- memblock_free(paddr, size);
- memblock_remove(paddr, size);
+ paddr = arm_memblock_steal(size, SZ_1M);
+
dram_io_desc[0].virtual = OMAP4_DRAM_BARRIER_VA;
dram_io_desc[0].pfn = __phys_to_pfn(paddr);
dram_io_desc[0].length = size;