[PATCH 11/31] lmb: Add get_free_all_memory_range()

[Yinghai Lu <yinghai@kernel.org>]

get_free_all_memory_range is for CONFIG_NO_BOOTMEM, and will be called by
free_all_memory_core_early().

It will use early_node_map aka active ranges subtract lmb.reserved to
get all free range.

-v2: Update with Jan Beulich's patch "fix allocation done in get_free_all_memory_range()", that one is for early_res.

Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Cc: Jan Beulich <jbeulich@novell.com>
---
 include/linux/lmb.h |    2 +
 mm/lmb.c            |   86 ++++++++++++++++++++++++++++++++++++++++++++++++++-
 2 files changed, 87 insertions(+), 1 deletions(-)

diff --git a/include/linux/lmb.h b/include/linux/lmb.h
index f5071e1..9e2dcf5 100644
--- a/include/linux/lmb.h
+++ b/include/linux/lmb.h
@@ -93,6 +93,8 @@ u64 find_lmb_area_size(u64 start, u64 *sizep, u64 align);
 u64 get_max_mapped(void);
 
 void lmb_to_bootmem(u64 start, u64 end);
+struct range;
+int get_free_all_memory_range(struct range **rangep, int nodeid);
 
 #include <asm/lmb.h>
 
diff --git a/mm/lmb.c b/mm/lmb.c
index 71a45b4..abece72 100644
--- a/mm/lmb.c
+++ b/mm/lmb.c
@@ -640,7 +640,91 @@ void __init free_lmb(u64 start, u64 end)
 	lmb_free(start, end - start);
 }
 
-#ifndef CONFIG_NO_BOOTMEM
+static __init struct range *find_range_array(int count)
+{
+	u64 end, size, mem = -1ULL;
+	struct range *range;
+
+	size = sizeof(struct range) * count;
+	end = get_max_mapped();
+#ifdef MAX_DMA32_PFN
+	if (end > (MAX_DMA32_PFN << PAGE_SHIFT))
+		mem = find_lmb_area(MAX_DMA32_PFN << PAGE_SHIFT, end,
+					 size, sizeof(struct range));
+#endif
+	if (mem == -1ULL)
+		mem = find_lmb_area(0, end, size, sizeof(struct range));
+	if (mem == -1ULL)
+		panic("can not find more space for range free");
+
+	range = __va(mem);
+	memset(range, 0, size);
+
+	return range;
+}
+
+#ifdef CONFIG_NO_BOOTMEM
+static void __init subtract_lmb_reserved(struct range *range, int az)
+{
+	int i, count;
+	u64 final_start, final_end;
+
+	/* Take out region array itself at first*/
+	if (lmb.reserved.region != lmb_reserved_region)
+		lmb_free(__pa(lmb.reserved.region), sizeof(struct lmb_property) * lmb.reserved.nr_regions);
+
+	count  = lmb.reserved.cnt;
+
+	pr_info("Subtract (%d early reservations)\n", count);
+
+	for (i = 0; i < count; i++) {
+		struct lmb_property *r = &lmb.reserved.region[i];
+		pr_info("  #%d [%010llx - %010llx]\n", i, r->base, r->base + r->size);
+		final_start = PFN_DOWN(r->base);
+		final_end = PFN_UP(r->base + r->size);
+		if (final_start >= final_end)
+			continue;
+		subtract_range(range, az, final_start, final_end);
+	}
+	/* Put region array back ? */
+	if (lmb.reserved.region != lmb_reserved_region)
+		lmb_reserve(__pa(lmb.reserved.region), sizeof(struct lmb_property) * lmb.reserved.nr_regions);
+}
+
+int __init get_free_all_memory_range(struct range **rangep, int nodeid)
+{
+	int count;
+	struct range *range;
+	int nr_range;
+
+	count = lmb.reserved.cnt * 2;
+
+	range = find_range_array(count);
+	nr_range = 0;
+
+	/*
+	 * Use early_node_map[] and lmb.reserved.region to get range array
+	 * at first
+	 */
+	nr_range = add_from_early_node_map(range, count, nr_range, nodeid);
+#ifdef CONFIG_X86_32
+	subtract_range(range, count, max_low_pfn, -1ULL);
+#endif
+	subtract_lmb_reserved(range, count);
+	nr_range = clean_sort_range(range, count);
+
+	/* Need to clear it ? */
+	if (nodeid == MAX_NUMNODES) {
+		memset(&lmb.reserved.region[0], 0, sizeof(struct lmb_property) * lmb.reserved.nr_regions);
+		lmb.reserved.region = NULL;
+		lmb.reserved.nr_regions = 0;
+		lmb.reserved.cnt = 0;
+	}
+
+	*rangep = range;
+	return nr_range;
+}
+#else
 void __init lmb_to_bootmem(u64 start, u64 end)
 {
 	int i, count;
-- 
1.6.4.2