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authorAKASHI Takahiro <takahiro.akashi@linaro.org>2017-04-03 11:23:55 +0900
committerAKASHI Takahiro <takahiro.akashi@linaro.org>2017-06-08 18:39:29 +0900
commit0bbb3d8a67d4282e5ccd24430c9f3c8955b7e689 (patch)
treebc952289b532ff4dbd62bb76072c4de5eb17e6f7
parent3acb7bc37d56d5dc80112459c0d72c6be8bde3c9 (diff)
downloadlinux-aarch64-0bbb3d8a67d4282e5ccd24430c9f3c8955b7e689.tar.gz
memblock: add memblock_cap_memory_range()
Add memblock_cap_memory_range() which will remove all the memblock regions except the memory range specified in the arguments. In addition, rework is done on memblock_mem_limit_remove_map() to re-implement it using memblock_cap_memory_range(). 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, or System RAM, on crash dump kernel. (Please note that "mem=" parameter is of little use for this purpose.) Signed-off-by: AKASHI Takahiro <takahiro.akashi@linaro.org> Reviewed-by: Will Deacon <will.deacon@arm.com> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Acked-by: Dennis Chen <dennis.chen@arm.com> Cc: linux-mm@kvack.org Cc: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
-rw-r--r--include/linux/memblock.h1
-rw-r--r--mm/memblock.c44
2 files changed, 30 insertions, 15 deletions
diff --git a/include/linux/memblock.h b/include/linux/memblock.h
index 25e1ff68a2f4..7ad0b3a8b78e 100644
--- a/include/linux/memblock.h
+++ b/include/linux/memblock.h
@@ -334,6 +334,7 @@ phys_addr_t memblock_mem_size(unsigned long limit_pfn);
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_cap_memory_range(phys_addr_t base, phys_addr_t size);
void memblock_mem_limit_remove_map(phys_addr_t limit);
bool memblock_is_memory(phys_addr_t addr);
int memblock_is_map_memory(phys_addr_t addr);
diff --git a/mm/memblock.c b/mm/memblock.c
index 183fd46598a6..9f6be749a36e 100644
--- a/mm/memblock.c
+++ b/mm/memblock.c
@@ -1526,11 +1526,37 @@ void __init memblock_enforce_memory_limit(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);
+}
+
void __init memblock_mem_limit_remove_map(phys_addr_t limit)
{
- struct memblock_type *type = &memblock.memory;
phys_addr_t max_addr;
- int i, ret, start_rgn, end_rgn;
if (!limit)
return;
@@ -1541,19 +1567,7 @@ void __init memblock_mem_limit_remove_map(phys_addr_t limit)
if (max_addr == (phys_addr_t)ULLONG_MAX)
return;
- ret = memblock_isolate_range(type, max_addr, (phys_addr_t)ULLONG_MAX,
- &start_rgn, &end_rgn);
- if (ret)
- return;
-
- /* remove all the MAP regions above the limit */
- for (i = end_rgn - 1; i >= start_rgn; i--) {
- if (!memblock_is_nomap(&type->regions[i]))
- memblock_remove_region(type, i);
- }
- /* truncate the reserved regions */
- memblock_remove_range(&memblock.reserved, max_addr,
- (phys_addr_t)ULLONG_MAX);
+ memblock_cap_memory_range(0, max_addr);
}
static int __init_memblock memblock_search(struct memblock_type *type, phys_addr_t addr)