From 307cfe715344e15eda12dad3bb14f794115ca823 Mon Sep 17 00:00:00 2001 From: Benjamin Herrenschmidt Date: Thu, 9 Jun 2011 16:52:38 +1000 Subject: powerpc: Force page alignment for initrd reserved memory When using 64K pages with a separate cpio rootfs, U-Boot will align the rootfs on a 4K page boundary. When the memory is reserved, and subsequent early memblock_alloc is called, it will allocate memory between the 64K page alignment and reserved memory. When the reserved memory is subsequently freed, it is done so by pages, causing the early memblock_alloc requests to be re-used, which in my case, caused the device-tree to be clobbered. This patch forces the reserved memory for initrd to be kernel page aligned, and will move the device tree if it overlaps with the range extension of initrd. This patch will also consolidate the identical function free_initrd_mem() from mm/init_32.c, init_64.c to mm/mem.c, and adds the same range extension when freeing initrd. free_initrd_mem() is also moved to the __init section. Many thanks to Milton Miller for his input on this patch. [BenH: Fixed build without CONFIG_BLK_DEV_INITRD] Signed-off-by: Dave Carroll Cc: Benjamin Herrenschmidt Signed-off-by: Benjamin Herrenschmidt --- arch/powerpc/mm/mem.c | 19 +++++++++++++++++++ 1 file changed, 19 insertions(+) (limited to 'arch/powerpc/mm/mem.c') diff --git a/arch/powerpc/mm/mem.c b/arch/powerpc/mm/mem.c index 57e545b84bf..29d4dde65c4 100644 --- a/arch/powerpc/mm/mem.c +++ b/arch/powerpc/mm/mem.c @@ -382,6 +382,25 @@ void __init mem_init(void) mem_init_done = 1; } +#ifdef CONFIG_BLK_DEV_INITRD +void __init free_initrd_mem(unsigned long start, unsigned long end) +{ + if (start >= end) + return; + + start = _ALIGN_DOWN(start, PAGE_SIZE); + end = _ALIGN_UP(end, PAGE_SIZE); + pr_info("Freeing initrd memory: %ldk freed\n", (end - start) >> 10); + + for (; start < end; start += PAGE_SIZE) { + ClearPageReserved(virt_to_page(start)); + init_page_count(virt_to_page(start)); + free_page(start); + totalram_pages++; + } +} +#endif + /* * This is called when a page has been modified by the kernel. * It just marks the page as not i-cache clean. We do the i-cache -- cgit v1.2.3-70-g09d2