Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754739AbcDNLCW (ORCPT ); Thu, 14 Apr 2016 07:02:22 -0400 Received: from foss.arm.com ([217.140.101.70]:41370 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754584AbcDNLCU (ORCPT ); Thu, 14 Apr 2016 07:02:20 -0400 Date: Thu, 14 Apr 2016 12:02:11 +0100 From: Steve Capper To: David Daney Cc: Will Deacon , linux-arm-kernel@lists.infradead.org, Rob Herring , Frank Rowand , Grant Likely , Pawel Moll , Ian Campbell , Kumar Gala , Ganapatrao Kulkarni , Robert Richter , Ard Biesheuvel , Matt Fleming , Mark Rutland , Catalin Marinas , devicetree@vger.kernel.org, linux-efi@vger.kernel.org, linux-kernel@vger.kernel.org, David Daney Subject: Re: [PATCH v16 1/6] efi: ARM/arm64: ignore DT memory nodes instead of removing them Message-ID: <20160414110210.GA11788@e103986-lin> References: <1460155828-8690-1-git-send-email-ddaney.cavm@gmail.com> <1460155828-8690-2-git-send-email-ddaney.cavm@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1460155828-8690-2-git-send-email-ddaney.cavm@gmail.com> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3315 Lines: 101 On Fri, Apr 08, 2016 at 03:50:23PM -0700, David Daney wrote: > From: Ard Biesheuvel > > There are two problems with the UEFI stub DT memory node removal > routine: > - it deletes nodes as it traverses the tree, which happens to work > but is not supported, as deletion invalidates the node iterator; > - deleting memory nodes entirely may discard annotations in the form > of additional properties on the nodes. > > Since the discovery of DT memory nodes occurs strictly before the > UEFI init sequence, we can simply clear the memblock memory table > before parsing the UEFI memory map. This way, it is no longer > necessary to remove the nodes, so we can remove that logic from the > stub as well. > > Signed-off-by: Ard Biesheuvel > Signed-off-by: David Daney > --- > drivers/firmware/efi/arm-init.c | 8 ++++++++ > drivers/firmware/efi/libstub/fdt.c | 24 +----------------------- > 2 files changed, 9 insertions(+), 23 deletions(-) > > diff --git a/drivers/firmware/efi/arm-init.c b/drivers/firmware/efi/arm-init.c > index aa1f743..5d6945b 100644 > --- a/drivers/firmware/efi/arm-init.c > +++ b/drivers/firmware/efi/arm-init.c > @@ -143,6 +143,14 @@ static __init void reserve_regions(void) > if (efi_enabled(EFI_DBG)) > pr_info("Processing EFI memory map:\n"); > > + /* > + * Discard memblocks discovered so far: if there are any at this > + * point, they originate from memory nodes in the DT, and UEFI > + * uses its own memory map instead. > + */ > + memblock_dump_all(); > + memblock_remove(0, ULLONG_MAX); > + Does this change need to be applied to any other architectures given that deletion code has been removed from libstub below? Cheers, -- Steve > for_each_efi_memory_desc(&memmap, md) { > paddr = md->phys_addr; > npages = md->num_pages; > diff --git a/drivers/firmware/efi/libstub/fdt.c b/drivers/firmware/efi/libstub/fdt.c > index 6dba78a..e58abfa 100644 > --- a/drivers/firmware/efi/libstub/fdt.c > +++ b/drivers/firmware/efi/libstub/fdt.c > @@ -24,7 +24,7 @@ efi_status_t update_fdt(efi_system_table_t *sys_table, void *orig_fdt, > unsigned long map_size, unsigned long desc_size, > u32 desc_ver) > { > - int node, prev, num_rsv; > + int node, num_rsv; > int status; > u32 fdt_val32; > u64 fdt_val64; > @@ -54,28 +54,6 @@ efi_status_t update_fdt(efi_system_table_t *sys_table, void *orig_fdt, > goto fdt_set_fail; > > /* > - * Delete any memory nodes present. We must delete nodes which > - * early_init_dt_scan_memory may try to use. > - */ > - prev = 0; > - for (;;) { > - const char *type; > - int len; > - > - node = fdt_next_node(fdt, prev, NULL); > - if (node < 0) > - break; > - > - type = fdt_getprop(fdt, node, "device_type", &len); > - if (type && strncmp(type, "memory", len) == 0) { > - fdt_del_node(fdt, node); > - continue; > - } > - > - prev = node; > - } > - > - /* > * Delete all memory reserve map entries. When booting via UEFI, > * kernel will use the UEFI memory map to find reserved regions. > */ > -- > 1.8.3.1 > > > _______________________________________________ > linux-arm-kernel mailing list > linux-arm-kernel@lists.infradead.org > http://lists.infradead.org/mailman/listinfo/linux-arm-kernel >