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author | David Hildenbrand <david@redhat.com> | 2020-07-01 16:18:29 +0200 |
---|---|---|
committer | Heiko Carstens <hca@linux.ibm.com> | 2020-07-10 15:08:09 +0200 |
commit | 776499058167d9f41c8eb468e21fe2d241c0b8e6 (patch) | |
tree | e76880b720c103e2e3bf87f9a60877481d3e8008 /mm | |
parent | a303e88743f6514995c31fe611011935ea7f040c (diff) | |
download | lwn-776499058167d9f41c8eb468e21fe2d241c0b8e6.tar.gz lwn-776499058167d9f41c8eb468e21fe2d241c0b8e6.zip |
mm/memblock: expose only miminal interface to add/walk physmem
"physmem" in the memblock allocator is somewhat weird: it's not actually
used for allocation, it's simply information collected during boot, which
describes the unmodified physical memory map at boot time, without any
standby/hotplugged memory. It's only used on s390 and is currently the
only reason s390 keeps using CONFIG_ARCH_KEEP_MEMBLOCK.
Physmem isn't numa aware and current users don't specify any flags. Let's
hide it from the user, exposing only for_each_physmem(), and simplify. The
interface for physmem is now really minimalistic:
- memblock_physmem_add() to add ranges
- for_each_physmem() / __next_physmem_range() to walk physmem ranges
Don't place it into an __init section and don't discard it without
CONFIG_ARCH_KEEP_MEMBLOCK. As we're reusing __next_mem_range(), remove
the __meminit notifier to avoid section mismatch warnings once
CONFIG_ARCH_KEEP_MEMBLOCK is no longer used with
CONFIG_HAVE_MEMBLOCK_PHYS_MAP.
While fixing up the documentation, sneak in some related cleanups. We can
stop setting CONFIG_ARCH_KEEP_MEMBLOCK for s390 next.
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: Mike Rapoport <rppt@linux.ibm.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Mike Rapoport <rppt@linux.ibm.com>
Message-Id: <20200701141830.18749-2-david@redhat.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Diffstat (limited to 'mm')
-rw-r--r-- | mm/memblock.c | 57 |
1 files changed, 29 insertions, 28 deletions
diff --git a/mm/memblock.c b/mm/memblock.c index 39aceafc57f6..45f198750be9 100644 --- a/mm/memblock.c +++ b/mm/memblock.c @@ -44,19 +44,20 @@ * in the system, for instance when the memory is restricted with * ``mem=`` command line parameter * * ``reserved`` - describes the regions that were allocated - * * ``physmap`` - describes the actual physical memory regardless of - * the possible restrictions; the ``physmap`` type is only available - * on some architectures. + * * ``physmem`` - describes the actual physical memory available during + * boot regardless of the possible restrictions and memory hot(un)plug; + * the ``physmem`` type is only available on some architectures. * * Each region is represented by :c:type:`struct memblock_region` that * defines the region extents, its attributes and NUMA node id on NUMA * systems. Every memory type is described by the :c:type:`struct * memblock_type` which contains an array of memory regions along with - * the allocator metadata. The memory types are nicely wrapped with - * :c:type:`struct memblock`. This structure is statically initialzed - * at build time. The region arrays for the "memory" and "reserved" - * types are initially sized to %INIT_MEMBLOCK_REGIONS and for the - * "physmap" type to %INIT_PHYSMEM_REGIONS. + * the allocator metadata. The "memory" and "reserved" types are nicely + * wrapped with :c:type:`struct memblock`. This structure is statically + * initialized at build time. The region arrays are initially sized to + * %INIT_MEMBLOCK_REGIONS for "memory" and %INIT_MEMBLOCK_RESERVED_REGIONS + * for "reserved". The region array for "physmem" is initially sized to + * %INIT_PHYSMEM_REGIONS. * The memblock_allow_resize() enables automatic resizing of the region * arrays during addition of new regions. This feature should be used * with care so that memory allocated for the region array will not @@ -87,8 +88,8 @@ * function frees all the memory to the buddy page allocator. * * Unless an architecture enables %CONFIG_ARCH_KEEP_MEMBLOCK, the - * memblock data structures will be discarded after the system - * initialization completes. + * memblock data structures (except "physmem") will be discarded after the + * system initialization completes. */ #ifndef CONFIG_NEED_MULTIPLE_NODES @@ -104,7 +105,7 @@ unsigned long long max_possible_pfn; static struct memblock_region memblock_memory_init_regions[INIT_MEMBLOCK_REGIONS] __initdata_memblock; static struct memblock_region memblock_reserved_init_regions[INIT_MEMBLOCK_RESERVED_REGIONS] __initdata_memblock; #ifdef CONFIG_HAVE_MEMBLOCK_PHYS_MAP -static struct memblock_region memblock_physmem_init_regions[INIT_PHYSMEM_REGIONS] __initdata_memblock; +static struct memblock_region memblock_physmem_init_regions[INIT_PHYSMEM_REGIONS]; #endif struct memblock memblock __initdata_memblock = { @@ -118,17 +119,19 @@ struct memblock memblock __initdata_memblock = { .reserved.max = INIT_MEMBLOCK_RESERVED_REGIONS, .reserved.name = "reserved", -#ifdef CONFIG_HAVE_MEMBLOCK_PHYS_MAP - .physmem.regions = memblock_physmem_init_regions, - .physmem.cnt = 1, /* empty dummy entry */ - .physmem.max = INIT_PHYSMEM_REGIONS, - .physmem.name = "physmem", -#endif - .bottom_up = false, .current_limit = MEMBLOCK_ALLOC_ANYWHERE, }; +#ifdef CONFIG_HAVE_MEMBLOCK_PHYS_MAP +struct memblock_type physmem = { + .regions = memblock_physmem_init_regions, + .cnt = 1, /* empty dummy entry */ + .max = INIT_PHYSMEM_REGIONS, + .name = "physmem", +}; +#endif + int memblock_debug __initdata_memblock; static bool system_has_some_mirror __initdata_memblock = false; static int memblock_can_resize __initdata_memblock; @@ -838,7 +841,7 @@ int __init_memblock memblock_physmem_add(phys_addr_t base, phys_addr_t size) memblock_dbg("%s: [%pa-%pa] %pS\n", __func__, &base, &end, (void *)_RET_IP_); - return memblock_add_range(&memblock.physmem, base, size, MAX_NUMNODES, 0); + return memblock_add_range(&physmem, base, size, MAX_NUMNODES, 0); } #endif @@ -1019,12 +1022,10 @@ static bool should_skip_region(struct memblock_region *m, int nid, int flags) * As both region arrays are sorted, the function advances the two indices * in lockstep and returns each intersection. */ -void __init_memblock __next_mem_range(u64 *idx, int nid, - enum memblock_flags flags, - struct memblock_type *type_a, - struct memblock_type *type_b, - phys_addr_t *out_start, - phys_addr_t *out_end, int *out_nid) +void __next_mem_range(u64 *idx, int nid, enum memblock_flags flags, + struct memblock_type *type_a, + struct memblock_type *type_b, phys_addr_t *out_start, + phys_addr_t *out_end, int *out_nid) { int idx_a = *idx & 0xffffffff; int idx_b = *idx >> 32; @@ -1924,7 +1925,7 @@ void __init_memblock __memblock_dump_all(void) memblock_dump(&memblock.memory); memblock_dump(&memblock.reserved); #ifdef CONFIG_HAVE_MEMBLOCK_PHYS_MAP - memblock_dump(&memblock.physmem); + memblock_dump(&physmem); #endif } @@ -2064,8 +2065,8 @@ static int __init memblock_init_debugfs(void) debugfs_create_file("reserved", 0444, root, &memblock.reserved, &memblock_debug_fops); #ifdef CONFIG_HAVE_MEMBLOCK_PHYS_MAP - debugfs_create_file("physmem", 0444, root, - &memblock.physmem, &memblock_debug_fops); + debugfs_create_file("physmem", 0444, root, &physmem, + &memblock_debug_fops); #endif return 0; |