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authorDavid Hildenbrand <david@redhat.com>2020-07-01 17:18:29 +0300
committerHeiko Carstens <hca@linux.ibm.com>2020-07-10 16:08:09 +0300
commit776499058167d9f41c8eb468e21fe2d241c0b8e6 (patch)
treee76880b720c103e2e3bf87f9a60877481d3e8008 /mm/memblock.c
parenta303e88743f6514995c31fe611011935ea7f040c (diff)
downloadlinux-776499058167d9f41c8eb468e21fe2d241c0b8e6.tar.xz
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/memblock.c')
-rw-r--r--mm/memblock.c57
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;