diff options
| author | Russell King <rmk+kernel@arm.linux.org.uk> | 2012-01-13 15:00:51 +0000 |
|---|---|---|
| committer | Russell King <rmk+kernel@arm.linux.org.uk> | 2012-01-13 15:02:35 +0000 |
| commit | 716a3dc20084da9b3ab17bd125005a5345e23e3b (patch) | |
| tree | f7ba487050d33fc2913fdee81b384f5578ccb105 /arch/arm/mm | |
| parent | 4de3a8e101150feaefa1139611a50ff37467f33e (diff) | |
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>
Diffstat (limited to 'arch/arm/mm')
| -rw-r--r-- | arch/arm/mm/init.c | 17 |
1 files changed, 17 insertions, 0 deletions
diff --git a/arch/arm/mm/init.c b/arch/arm/mm/init.c index e34ea8adc1f..6ec1226fc62 100644 --- a/arch/arm/mm/init.c +++ b/arch/arm/mm/init.c @@ -22,6 +22,7 @@ #include <linux/memblock.h> #include <asm/mach-types.h> +#include <asm/memblock.h> #include <asm/prom.h> #include <asm/sections.h> #include <asm/setup.h> @@ -307,6 +308,21 @@ static void arm_memory_present(void) } #endif +static bool arm_memblock_steal_permitted = true; + +phys_addr_t arm_memblock_steal(phys_addr_t size, phys_addr_t align) +{ + phys_addr_t phys; + + BUG_ON(!arm_memblock_steal_permitted); + + phys = memblock_alloc(size, align); + memblock_free(phys, size); + memblock_remove(phys, size); + + return phys; +} + void __init arm_memblock_init(struct meminfo *mi, struct machine_desc *mdesc) { int i; @@ -349,6 +365,7 @@ void __init arm_memblock_init(struct meminfo *mi, struct machine_desc *mdesc) if (mdesc->reserve) mdesc->reserve(); + arm_memblock_steal_permitted = false; memblock_allow_resize(); memblock_dump_all(); } |