Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754855AbbHQLXD (ORCPT ); Mon, 17 Aug 2015 07:23:03 -0400 Received: from foss.arm.com ([217.140.101.70]:45116 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752600AbbHQLXB (ORCPT ); Mon, 17 Aug 2015 07:23:01 -0400 Date: Mon, 17 Aug 2015 12:22:56 +0100 From: Will Deacon To: Mark Salter Cc: Catalin Marinas , "x86@kernel.org" , Andrew Morton , Arnd Bergmann , Ard Biesheuvel , Mark Rutland , "linux-kernel@vger.kernel.org" , "linux-arm-kernel@lists.infradead.org" , "linux-mm@kvack.org" , "linux-arch@vger.kernel.org" Subject: Re: [PATCH V3 2/3] arm64: support initrd outside kernel linear map Message-ID: <20150817112256.GH1688@arm.com> References: <1439758168-29427-1-git-send-email-msalter@redhat.com> <1439758168-29427-3-git-send-email-msalter@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1439758168-29427-3-git-send-email-msalter@redhat.com> User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2819 Lines: 91 Hi Mark, On Sun, Aug 16, 2015 at 09:49:27PM +0100, Mark Salter wrote: > The use of mem= could leave part or all of the initrd outside of > the kernel linear map. This will lead to an error when unpacking > the initrd and a probable failure to boot. This patch catches that > situation and relocates the initrd to be fully within the linear > map. > > Signed-off-by: Mark Salter > --- > arch/arm64/kernel/setup.c | 59 +++++++++++++++++++++++++++++++++++++++++++++++ > 1 file changed, 59 insertions(+) > > diff --git a/arch/arm64/kernel/setup.c b/arch/arm64/kernel/setup.c > index f3067d4..5f45fd9 100644 > --- a/arch/arm64/kernel/setup.c > +++ b/arch/arm64/kernel/setup.c > @@ -359,6 +359,64 @@ static void __init request_standard_resources(void) > } > } > > +#ifdef CONFIG_BLK_DEV_INITRD > +/* > + * Relocate initrd if it is not completely within the linear mapping. > + * This would be the case if mem= cuts out all or part of it. > + */ > +static void __init relocate_initrd(void) > +{ > + phys_addr_t orig_start = __virt_to_phys(initrd_start); > + phys_addr_t orig_end = __virt_to_phys(initrd_end); Any particular reason to use the __* variants here? > + phys_addr_t ram_end = memblock_end_of_DRAM(); > + phys_addr_t new_start; > + unsigned long size, to_free = 0; > + void *dest; > + > + if (orig_end <= ram_end) > + return; > + > + /* Note if any of original initrd will freeing below */ The comment doesn't make sense. > + if (orig_start < ram_end) > + to_free = ram_end - orig_start; > + > + size = orig_end - orig_start; > + > + /* initrd needs to be relocated completely inside linear mapping */ > + new_start = memblock_find_in_range(0, PFN_PHYS(max_pfn), > + size, PAGE_SIZE); > + if (!new_start) > + panic("Cannot relocate initrd of size %ld\n", size); > + memblock_reserve(new_start, size); > + > + initrd_start = __phys_to_virt(new_start); > + initrd_end = initrd_start + size; > + > + pr_info("Moving initrd from [%llx-%llx] to [%llx-%llx]\n", > + orig_start, orig_start + size - 1, > + new_start, new_start + size - 1); > + > + dest = (void *)initrd_start; > + > + if (to_free) { > + memcpy(dest, (void *)__phys_to_virt(orig_start), to_free); > + dest += to_free; > + } > + > + copy_from_early_mem(dest, orig_start + to_free, size - to_free); > + > + if (to_free) { > + pr_info("Freeing original RAMDISK from [%llx-%llx]\n", > + orig_start, orig_start + to_free - 1); > + memblock_free(orig_start, to_free); > + } > +} > +#else > +static inline void __init reserve_initrd(void) relocate_initrd ? Will -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/