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authorMike Rapoport <rppt@linux.ibm.com>2019-03-12 09:30:54 +0300
committerLinus Torvalds <torvalds@linux-foundation.org>2019-03-12 20:04:02 +0300
commita2974133b7e0a31c71fabe86aad42a61db4f01ed (patch)
treeb2fa78a6f869e328d8c2c605db7bb164a4c8e0ae
parentc9a688a3e918c4eb4f3916ff99a6dae8995af41b (diff)
downloadlinux-a2974133b7e0a31c71fabe86aad42a61db4f01ed.tar.xz
mm: memblock: update comments and kernel-doc
* Remove comments mentioning bootmem * Extend "DOC: memblock overview" * Add kernel-doc comments for several more functions [akpm@linux-foundation.org: fix copy-n-paste error] Link: http://lkml.kernel.org/r/1549626347-25461-1-git-send-email-rppt@linux.ibm.com Signed-off-by: Mike Rapoport <rppt@linux.ibm.com> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Cc: Jonathan Corbet <corbet@lwn.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-rw-r--r--mm/memblock.c60
1 files changed, 43 insertions, 17 deletions
diff --git a/mm/memblock.c b/mm/memblock.c
index dfe90bc210d9..e7665cf914b1 100644
--- a/mm/memblock.c
+++ b/mm/memblock.c
@@ -76,8 +76,19 @@
* :c:func:`memblock_set_node`. The :c:func:`memblock_add_node`
* performs such an assignment directly.
*
- * Once memblock is setup the memory can be allocated using either
- * memblock or bootmem APIs.
+ * Once memblock is setup the memory can be allocated using one of the
+ * API variants:
+ *
+ * * :c:func:`memblock_phys_alloc*` - these functions return the
+ * **physical** address of the allocated memory
+ * * :c:func:`memblock_alloc*` - these functions return the **virtual**
+ * address of the allocated memory.
+ *
+ * Note, that both API variants use implict assumptions about allowed
+ * memory ranges and the fallback methods. Consult the documentation
+ * of :c:func:`memblock_alloc_internal` and
+ * :c:func:`memblock_alloc_range_nid` functions for more elaboarte
+ * description.
*
* As the system boot progresses, the architecture specific
* :c:func:`mem_init` function frees all the memory to the buddy page
@@ -435,17 +446,7 @@ static int __init_memblock memblock_double_array(struct memblock_type *type,
else
in_slab = &memblock_reserved_in_slab;
- /* Try to find some space for it.
- *
- * WARNING: We assume that either slab_is_available() and we use it or
- * we use MEMBLOCK for allocations. That means that this is unsafe to
- * use when bootmem is currently active (unless bootmem itself is
- * implemented on top of MEMBLOCK which isn't the case yet)
- *
- * This should however not be an issue for now, as we currently only
- * call into MEMBLOCK while it's still active, or much later when slab
- * is active for memory hotplug operations
- */
+ /* Try to find some space for it */
if (use_slab) {
new_array = kmalloc(new_size, GFP_KERNEL);
addr = new_array ? __pa(new_array) : 0;
@@ -989,7 +990,7 @@ static bool should_skip_region(struct memblock_region *m, int nid, int flags)
}
/**
- * __next__mem_range - next function for for_each_free_mem_range() etc.
+ * __next_mem_range - next function for for_each_free_mem_range() etc.
* @idx: pointer to u64 loop variable
* @nid: node selector, %NUMA_NO_NODE for all nodes
* @flags: pick from blocks based on memory attributes
@@ -1335,6 +1336,18 @@ done:
return found;
}
+/**
+ * memblock_phys_alloc_range - allocate a memory block inside specified range
+ * @size: size of memory block to be allocated in bytes
+ * @align: alignment of the region and block's size
+ * @start: the lower bound of the memory region to allocate (physical address)
+ * @end: the upper bound of the memory region to allocate (physical address)
+ *
+ * Allocate @size bytes in the between @start and @end.
+ *
+ * Return: physical address of the allocated memory block on success,
+ * %0 on failure.
+ */
phys_addr_t __init memblock_phys_alloc_range(phys_addr_t size,
phys_addr_t align,
phys_addr_t start,
@@ -1343,6 +1356,19 @@ phys_addr_t __init memblock_phys_alloc_range(phys_addr_t size,
return memblock_alloc_range_nid(size, align, start, end, NUMA_NO_NODE);
}
+/**
+ * memblock_phys_alloc_try_nid - allocate a memory block from specified MUMA node
+ * @size: size of memory block to be allocated in bytes
+ * @align: alignment of the region and block's size
+ * @nid: nid of the free area to find, %NUMA_NO_NODE for any node
+ *
+ * Allocates memory block from the specified NUMA node. If the node
+ * has no available memory, attempts to allocated from any node in the
+ * system.
+ *
+ * Return: physical address of the allocated memory block on success,
+ * %0 on failure.
+ */
phys_addr_t __init memblock_phys_alloc_try_nid(phys_addr_t size, phys_addr_t align, int nid)
{
return memblock_alloc_range_nid(size, align, 0,
@@ -1469,13 +1495,13 @@ void * __init memblock_alloc_try_nid(
}
/**
- * __memblock_free_late - free bootmem block pages directly to buddy allocator
+ * __memblock_free_late - free pages directly to buddy allocator
* @base: phys starting address of the boot memory block
* @size: size of the boot memory block in bytes
*
- * This is only useful when the bootmem allocator has already been torn
+ * This is only useful when the memblock allocator has already been torn
* down, but we are still initializing the system. Pages are released directly
- * to the buddy allocator, no bootmem metadata is updated because it is gone.
+ * to the buddy allocator.
*/
void __init __memblock_free_late(phys_addr_t base, phys_addr_t size)
{