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-rw-r--r--mm/memblock.c104
1 files changed, 102 insertions, 2 deletions
diff --git a/mm/memblock.c b/mm/memblock.c
index e5f3f9b..0787790 100644
--- a/mm/memblock.c
+++ b/mm/memblock.c
@@ -11,6 +11,7 @@
*/
#include <linux/kernel.h>
+#include <linux/slab.h>
#include <linux/init.h>
#include <linux/bitops.h>
#include <linux/poison.h>
@@ -18,12 +19,23 @@
struct memblock memblock;
-static int memblock_debug;
+static int memblock_debug, memblock_can_resize;
static struct memblock_region memblock_memory_init_regions[INIT_MEMBLOCK_REGIONS + 1];
static struct memblock_region memblock_reserved_init_regions[INIT_MEMBLOCK_REGIONS + 1];
#define MEMBLOCK_ERROR (~(phys_addr_t)0)
+/* inline so we don't get a warning when pr_debug is compiled out */
+static inline const char *memblock_type_name(struct memblock_type *type)
+{
+ if (type == &memblock.memory)
+ return "memory";
+ else if (type == &memblock.reserved)
+ return "reserved";
+ else
+ return "unknown";
+}
+
/*
* Address comparison utilities
*/
@@ -156,6 +168,79 @@ static void memblock_coalesce_regions(struct memblock_type *type,
memblock_remove_region(type, r2);
}
+/* Defined below but needed now */
+static long memblock_add_region(struct memblock_type *type, phys_addr_t base, phys_addr_t size);
+
+static int memblock_double_array(struct memblock_type *type)
+{
+ struct memblock_region *new_array, *old_array;
+ phys_addr_t old_size, new_size, addr;
+ int use_slab = slab_is_available();
+
+ /* We don't allow resizing until we know about the reserved regions
+ * of memory that aren't suitable for allocation
+ */
+ if (!memblock_can_resize)
+ return -1;
+
+ pr_debug("memblock: %s array full, doubling...", memblock_type_name(type));
+
+ /* Calculate new doubled size */
+ old_size = type->max * sizeof(struct memblock_region);
+ new_size = old_size << 1;
+
+ /* 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) {
+ new_array = kmalloc(new_size, GFP_KERNEL);
+ addr = new_array == NULL ? MEMBLOCK_ERROR : __pa(new_array);
+ } else
+ addr = memblock_find_base(new_size, sizeof(phys_addr_t), MEMBLOCK_ALLOC_ACCESSIBLE);
+ if (addr == MEMBLOCK_ERROR) {
+ pr_err("memblock: Failed to double %s array from %ld to %ld entries !\n",
+ memblock_type_name(type), type->max, type->max * 2);
+ return -1;
+ }
+ new_array = __va(addr);
+
+ /* Found space, we now need to move the array over before
+ * we add the reserved region since it may be our reserved
+ * array itself that is full.
+ */
+ memcpy(new_array, type->regions, old_size);
+ memset(new_array + type->max, 0, old_size);
+ old_array = type->regions;
+ type->regions = new_array;
+ type->max <<= 1;
+
+ /* If we use SLAB that's it, we are done */
+ if (use_slab)
+ return 0;
+
+ /* Add the new reserved region now. Should not fail ! */
+ BUG_ON(memblock_add_region(&memblock.reserved, addr, new_size) < 0);
+
+ /* If the array wasn't our static init one, then free it. We only do
+ * that before SLAB is available as later on, we don't know whether
+ * to use kfree or free_bootmem_pages(). Shouldn't be a big deal
+ * anyways
+ */
+ if (old_array != memblock_memory_init_regions &&
+ old_array != memblock_reserved_init_regions)
+ memblock_free(__pa(old_array), old_size);
+
+ return 0;
+}
+
static long memblock_add_region(struct memblock_type *type, phys_addr_t base, phys_addr_t size)
{
unsigned long coalesced = 0;
@@ -196,7 +281,11 @@ static long memblock_add_region(struct memblock_type *type, phys_addr_t base, ph
if (coalesced)
return coalesced;
- if (type->cnt >= type->max)
+
+ /* If we are out of space, we fail. It's too late to resize the array
+ * but then this shouldn't have happened in the first place.
+ */
+ if (WARN_ON(type->cnt >= type->max))
return -1;
/* Couldn't coalesce the MEMBLOCK, so add it to the sorted table. */
@@ -217,6 +306,14 @@ static long memblock_add_region(struct memblock_type *type, phys_addr_t base, ph
}
type->cnt++;
+ /* The array is full ? Try to resize it. If that fails, we undo
+ * our allocation and return an error
+ */
+ if (type->cnt == type->max && memblock_double_array(type)) {
+ type->cnt--;
+ return -1;
+ }
+
return 0;
}
@@ -541,6 +638,9 @@ void __init memblock_analyze(void)
for (i = 0; i < memblock.memory.cnt; i++)
memblock.memory_size += memblock.memory.regions[i].size;
+
+ /* We allow resizing from there */
+ memblock_can_resize = 1;
}
void __init memblock_init(void)
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