lkml.org 
[lkml]   [2010]   [Aug]   [6]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH 04/43] memblock: Implement memblock_is_memory and memblock_is_region_memory
Date
To make it fast, we steal ARM's binary search for memblock_is_memory()
and we use that to also the replace existing implementation of
memblock_is_reserved().

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
---
include/linux/memblock.h | 2 ++
mm/memblock.c | 42 ++++++++++++++++++++++++++++++++++--------
2 files changed, 36 insertions(+), 8 deletions(-)
diff --git a/include/linux/memblock.h b/include/linux/memblock.h
index 4b69313..47bceb1 100644
--- a/include/linux/memblock.h
+++ b/include/linux/memblock.h
@@ -56,6 +56,8 @@ extern u64 __init __memblock_alloc_base(u64 size,
extern u64 __init memblock_phys_mem_size(void);
extern u64 memblock_end_of_DRAM(void);
extern void __init memblock_enforce_memory_limit(u64 memory_limit);
+extern int memblock_is_memory(u64 addr);
+extern int memblock_is_region_memory(u64 base, u64 size);
extern int __init memblock_is_reserved(u64 addr);
extern int memblock_is_region_reserved(u64 base, u64 size);
extern int memblock_find(struct memblock_region *res);
diff --git a/mm/memblock.c b/mm/memblock.c
index 6f407cc..aa88c62 100644
--- a/mm/memblock.c
+++ b/mm/memblock.c
@@ -487,17 +487,43 @@ void __init memblock_enforce_memory_limit(u64 memory_limit)
}
}

+static int memblock_search(struct memblock_type *type, u64 addr)
+{
+ unsigned int left = 0, right = type->cnt;
+
+ do {
+ unsigned int mid = (right + left) / 2;
+
+ if (addr < type->regions[mid].base)
+ right = mid;
+ else if (addr >= (type->regions[mid].base +
+ type->regions[mid].size))
+ left = mid + 1;
+ else
+ return mid;
+ } while (left < right);
+ return -1;
+}
+
int __init memblock_is_reserved(u64 addr)
{
- int i;
+ return memblock_search(&memblock.reserved, addr) != -1;
+}

- for (i = 0; i < memblock.reserved.cnt; i++) {
- u64 upper = memblock.reserved.regions[i].base +
- memblock.reserved.regions[i].size - 1;
- if ((addr >= memblock.reserved.regions[i].base) && (addr <= upper))
- return 1;
- }
- return 0;
+int memblock_is_memory(u64 addr)
+{
+ return memblock_search(&memblock.memory, addr) != -1;
+}
+
+int memblock_is_region_memory(u64 base, u64 size)
+{
+ int idx = memblock_search(&memblock.reserved, base);
+
+ if (idx == -1)
+ return 0;
+ return memblock.reserved.regions[idx].base <= base &&
+ (memblock.reserved.regions[idx].base +
+ memblock.reserved.regions[idx].size) >= (base + size);
}

int memblock_is_region_reserved(u64 base, u64 size)
--
1.7.0.4


\
 
 \ /
  Last update: 2010-08-06 07:27    [from the cache]
©2003-2011 Jasper Spaans