From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pa0-f71.google.com (mail-pa0-f71.google.com [209.85.220.71]) by kanga.kvack.org (Postfix) with ESMTP id 5F80E6B02AB for ; Wed, 2 Nov 2016 00:43:48 -0400 (EDT) Received: by mail-pa0-f71.google.com with SMTP id rf5so2530317pab.3 for ; Tue, 01 Nov 2016 21:43:48 -0700 (PDT) Received: from mail-pf0-x22f.google.com (mail-pf0-x22f.google.com. [2607:f8b0:400e:c00::22f]) by mx.google.com with ESMTPS id o7si414448pae.227.2016.11.01.21.43.47 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Tue, 01 Nov 2016 21:43:47 -0700 (PDT) Received: by mail-pf0-x22f.google.com with SMTP id 189so4207144pfz.3 for ; Tue, 01 Nov 2016 21:43:47 -0700 (PDT) From: AKASHI Takahiro Subject: [PATCH v27 1/9] memblock: add memblock_cap_memory_range() Date: Wed, 2 Nov 2016 13:51:53 +0900 Message-Id: <20161102045153.12008-1-takahiro.akashi@linaro.org> In-Reply-To: <20161102044959.11954-1-takahiro.akashi@linaro.org> References: <20161102044959.11954-1-takahiro.akashi@linaro.org> Sender: owner-linux-mm@kvack.org List-ID: To: catalin.marinas@arm.com, will.deacon@arm.com, akpm@linux-foundation.org Cc: james.morse@arm.com, geoff@infradead.org, bauerman@linux.vnet.ibm.com, dyoung@redhat.com, mark.rutland@arm.com, kexec@lists.infradead.org, linux-arm-kernel@lists.infradead.org, linux-mm@kvack.org, AKASHI Takahiro Add memblock_cap_memory_range() which will remove all the memblock regions except the range specified in the arguments. This function, like memblock_mem_limit_remove_map(), will not remove memblocks with MEMMAP_NOMAP attribute as they may be mapped and accessed later as "device memory." See the commit a571d4eb55d8 ("mm/memblock.c: add new infrastructure to address the mem limit issue"). This function is used, in a succeeding patch in the series of arm64 kdump suuport, to limit the range of usable memory, System RAM, on crash dump kernel. (Please note that "mem=" parameter is of little use for this purpose.) Signed-off-by: AKASHI Takahiro Cc: linux-mm@kvack.org Cc: Andrew Morton --- include/linux/memblock.h | 1 + mm/memblock.c | 28 ++++++++++++++++++++++++++++ 2 files changed, 29 insertions(+) diff --git a/include/linux/memblock.h b/include/linux/memblock.h index 5b759c9..0e770af 100644 --- a/include/linux/memblock.h +++ b/include/linux/memblock.h @@ -334,6 +334,7 @@ phys_addr_t memblock_start_of_DRAM(void); phys_addr_t memblock_end_of_DRAM(void); void memblock_enforce_memory_limit(phys_addr_t memory_limit); void memblock_mem_limit_remove_map(phys_addr_t limit); +void memblock_cap_memory_range(phys_addr_t base, phys_addr_t size); bool memblock_is_memory(phys_addr_t addr); int memblock_is_map_memory(phys_addr_t addr); int memblock_is_region_memory(phys_addr_t base, phys_addr_t size); diff --git a/mm/memblock.c b/mm/memblock.c index 7608bc3..eb53876 100644 --- a/mm/memblock.c +++ b/mm/memblock.c @@ -1544,6 +1544,34 @@ void __init memblock_mem_limit_remove_map(phys_addr_t limit) (phys_addr_t)ULLONG_MAX); } +void __init memblock_cap_memory_range(phys_addr_t base, phys_addr_t size) +{ + int start_rgn, end_rgn; + int i, ret; + + if (!size) + return; + + ret = memblock_isolate_range(&memblock.memory, base, size, + &start_rgn, &end_rgn); + if (ret) + return; + + /* remove all the MAP regions */ + for (i = memblock.memory.cnt - 1; i >= end_rgn; i--) + if (!memblock_is_nomap(&memblock.memory.regions[i])) + memblock_remove_region(&memblock.memory, i); + + for (i = start_rgn - 1; i >= 0; i--) + if (!memblock_is_nomap(&memblock.memory.regions[i])) + memblock_remove_region(&memblock.memory, i); + + /* truncate the reserved regions */ + memblock_remove_range(&memblock.reserved, 0, base); + memblock_remove_range(&memblock.reserved, + base + size, (phys_addr_t)ULLONG_MAX); +} + static int __init_memblock memblock_search(struct memblock_type *type, phys_addr_t addr) { unsigned int left = 0, right = type->cnt; -- 2.10.0 -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org