Commit a2974133 authored by Mike Rapoport's avatar Mike Rapoport Committed by Linus Torvalds

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.comSigned-off-by: default avatarMike Rapoport <rppt@linux.ibm.com>
Reviewed-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent c9a688a3
...@@ -76,8 +76,19 @@ ...@@ -76,8 +76,19 @@
* :c:func:`memblock_set_node`. The :c:func:`memblock_add_node` * :c:func:`memblock_set_node`. The :c:func:`memblock_add_node`
* performs such an assignment directly. * performs such an assignment directly.
* *
* Once memblock is setup the memory can be allocated using either * Once memblock is setup the memory can be allocated using one of the
* memblock or bootmem APIs. * 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 * As the system boot progresses, the architecture specific
* :c:func:`mem_init` function frees all the memory to the buddy page * :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, ...@@ -435,17 +446,7 @@ static int __init_memblock memblock_double_array(struct memblock_type *type,
else else
in_slab = &memblock_reserved_in_slab; in_slab = &memblock_reserved_in_slab;
/* Try to find some space for it. /* 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
*/
if (use_slab) { if (use_slab) {
new_array = kmalloc(new_size, GFP_KERNEL); new_array = kmalloc(new_size, GFP_KERNEL);
addr = new_array ? __pa(new_array) : 0; addr = new_array ? __pa(new_array) : 0;
...@@ -989,7 +990,7 @@ static bool should_skip_region(struct memblock_region *m, int nid, int flags) ...@@ -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 * @idx: pointer to u64 loop variable
* @nid: node selector, %NUMA_NO_NODE for all nodes * @nid: node selector, %NUMA_NO_NODE for all nodes
* @flags: pick from blocks based on memory attributes * @flags: pick from blocks based on memory attributes
...@@ -1335,6 +1336,18 @@ static phys_addr_t __init memblock_alloc_range_nid(phys_addr_t size, ...@@ -1335,6 +1336,18 @@ static phys_addr_t __init memblock_alloc_range_nid(phys_addr_t size,
return found; 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 __init memblock_phys_alloc_range(phys_addr_t size,
phys_addr_t align, phys_addr_t align,
phys_addr_t start, phys_addr_t start,
...@@ -1343,6 +1356,19 @@ phys_addr_t __init memblock_phys_alloc_range(phys_addr_t size, ...@@ -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); 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) 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, return memblock_alloc_range_nid(size, align, 0,
...@@ -1469,13 +1495,13 @@ void * __init memblock_alloc_try_nid( ...@@ -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 * @base: phys starting address of the boot memory block
* @size: size of the boot memory block in bytes * @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 * 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) void __init __memblock_free_late(phys_addr_t base, phys_addr_t size)
{ {
......
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