Hello,
On 2014-02-05 11:15, Grant Likely wrote:
On Tue, 04 Feb 2014 13:09:32 +0100, Marek Szyprowski m.szyprowski@samsung.com wrote:
Enable reserved memory initialization from device tree.
Cc: Benjamin Herrenschmidt benh@kernel.crashing.org Cc: Laura Abbott lauraa@codeaurora.org Signed-off-by: Marek Szyprowski m.szyprowski@samsung.com
arch/arm/mm/init.c | 3 +++ 1 file changed, 3 insertions(+)
diff --git a/arch/arm/mm/init.c b/arch/arm/mm/init.c index 804d61566a53..ebafdb479410 100644 --- a/arch/arm/mm/init.c +++ b/arch/arm/mm/init.c @@ -17,6 +17,7 @@ #include <linux/nodemask.h> #include <linux/initrd.h> #include <linux/of_fdt.h> +#include <linux/of_reserved_mem.h> #include <linux/highmem.h> #include <linux/gfp.h> #include <linux/memblock.h> @@ -323,6 +324,8 @@ void __init arm_memblock_init(struct meminfo *mi, if (mdesc->reserve) mdesc->reserve();
- early_init_dt_scan_reserved_mem();
The new binding is being made fundamental. If the reserved-memory node is present, then it needs to be honored, even if the kernel doesn't know how to use the regions. Therefore, This needs to be unconditional for all architectures. The hook should be called in early_init_dt_scan() (drivers/of/fdt.c) immediately after the early_init_dt_scan_memory() hook.
In theory this will be the best solution, but it practice there is a problem. early_init_dt_scan() is called as the first function from kernel booting code. That time there is no memory yet added to the system, so it would be really hard to reserve anything. Memory nodes are being added later either with memblock_add() or by some other arch specific way.
Finally, once all memory has been added to the system we can parse and reserve all regions defined in the device tree. This really requires creating another function which will be called by arch specific code.
Best regards