diff options
| -rw-r--r-- | include/linux/memblock.h | 20 | ||||
| -rw-r--r-- | mm/memblock.c | 76 |
2 files changed, 96 insertions, 0 deletions
diff --git a/include/linux/memblock.h b/include/linux/memblock.h index c36a55d3c1c2..31def584cceb 100644 --- a/include/linux/memblock.h +++ b/include/linux/memblock.h @@ -61,6 +61,26 @@ extern long memblock_remove(phys_addr_t base, phys_addr_t size); extern long memblock_free(phys_addr_t base, phys_addr_t size); extern long memblock_reserve(phys_addr_t base, phys_addr_t size); +extern void __next_free_mem_range(u64 *idx, int nid, phys_addr_t *out_start, + phys_addr_t *out_end, int *out_nid); + +/** + * for_each_free_mem_range - iterate through free memblock areas + * @i: u64 used as loop variable + * @nid: node selector, %MAX_NUMNODES for all nodes + * @p_start: ptr to phys_addr_t for start address of the range, can be %NULL + * @p_end: ptr to phys_addr_t for end address of the range, can be %NULL + * @p_nid: ptr to int for nid of the range, can be %NULL + * + * Walks over free (memory && !reserved) areas of memblock. Available as + * soon as memblock is initialized. + */ +#define for_each_free_mem_range(i, nid, p_start, p_end, p_nid) \ + for (i = 0, \ + __next_free_mem_range(&i, nid, p_start, p_end, p_nid); \ + i != (u64)ULLONG_MAX; \ + __next_free_mem_range(&i, nid, p_start, p_end, p_nid)) + #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP extern int memblock_set_node(phys_addr_t base, phys_addr_t size, int nid); diff --git a/mm/memblock.c b/mm/memblock.c index e815f4b75809..c4a8750406fc 100644 --- a/mm/memblock.c +++ b/mm/memblock.c @@ -461,6 +461,82 @@ long __init_memblock memblock_reserve(phys_addr_t base, phys_addr_t size) return memblock_add_region(_rgn, base, size); } +/** + * __next_free_mem_range - next function for for_each_free_mem_range() + * @idx: pointer to u64 loop variable + * @nid: nid: node selector, %MAX_NUMNODES for all nodes + * @p_start: ptr to phys_addr_t for start address of the range, can be %NULL + * @p_end: ptr to phys_addr_t for end address of the range, can be %NULL + * @p_nid: ptr to int for nid of the range, can be %NULL + * + * Find the first free area from *@idx which matches @nid, fill the out + * parameters, and update *@idx for the next iteration. The lower 32bit of + * *@idx contains index into memory region and the upper 32bit indexes the + * areas before each reserved region. For example, if reserved regions + * look like the following, + * + * 0:[0-16), 1:[32-48), 2:[128-130) + * + * The upper 32bit indexes the following regions. + * + * 0:[0-0), 1:[16-32), 2:[48-128), 3:[130-MAX) + * + * As both region arrays are sorted, the function advances the two indices + * in lockstep and returns each intersection. + */ +void __init_memblock __next_free_mem_range(u64 *idx, int nid, + phys_addr_t *out_start, + phys_addr_t *out_end, int *out_nid) +{ + struct memblock_type *mem = &memblock.memory; + struct memblock_type *rsv = &memblock.reserved; + int mi = *idx & 0xffffffff; + int ri = *idx >> 32; + + for ( ; mi < mem->cnt; mi++) { + struct memblock_region *m = &mem->regions[mi]; + phys_addr_t m_start = m->base; + phys_addr_t m_end = m->base + m->size; + + /* only memory regions are associated with nodes, check it */ + if (nid != MAX_NUMNODES && nid != memblock_get_region_node(m)) + continue; + + /* scan areas before each reservation for intersection */ + for ( ; ri < rsv->cnt + 1; ri++) { + struct memblock_region *r = &rsv->regions[ri]; + phys_addr_t r_start = ri ? r[-1].base + r[-1].size : 0; + phys_addr_t r_end = ri < rsv->cnt ? r->base : ULLONG_MAX; + + /* if ri advanced past mi, break out to advance mi */ + if (r_start >= m_end) + break; + /* if the two regions intersect, we're done */ + if (m_start < r_end) { + if (out_start) + *out_start = max(m_start, r_start); + if (out_end) + *out_end = min(m_end, r_end); + if (out_nid) + *out_nid = memblock_get_region_node(m); + /* + * The region which ends first is advanced + * for the next iteration. + */ + if (m_end <= r_end) + mi++; + else + ri++; + *idx = (u32)mi | (u64)ri << 32; + return; + } + } + } + + /* signal end of iteration */ + *idx = ULLONG_MAX; +} + #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP /* * Common iterator interface used to define for_each_mem_range(). |