x86: Use absent_pages_in_range() instead of memblock_x86_hole_size()

memblock_x86_hole_size() calculates the total size of holes in a given
range according to memblock and is used by numa emulation code and
numa_meminfo_cover_memory().

Since conversion to MEMBLOCK_NODE_MAP, absent_pages_in_range() also
uses memblock and gives the same result.  This patch replaces
memblock_x86_hole_size() uses with absent_pages_in_range().  After the
conversion the x86 function doesn't have any user left and is killed.

Signed-off-by: Tejun Heo <tj@kernel.org>
Link: http://lkml.kernel.org/r/1310462166-31469-12-git-send-email-tj@kernel.org
Cc: Yinghai Lu <yinghai@kernel.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>

3 files changed, 20 insertions, 66 deletions

diff --git a/arch/x86/mm/memblock.c b/arch/x86/mm/memblock.c
index a9d0972df10a..7325c5d8ace5 100644
--- a/arch/x86/mm/memblock.c
+++ b/arch/x86/mm/memblock.c
@@ -32,55 +32,3 @@ void __init memblock_x86_free_range(u64 start, u64 end)
 
         memblock_free(start, end - start);
 }
-
-/*
- * Finds an active region in the address range from start_pfn to last_pfn and
- * returns its range in ei_startpfn and ei_endpfn for the memblock entry.
- */
-static int __init memblock_x86_find_active_region(const struct memblock_region *ei,
-                                  unsigned long start_pfn,
-                                  unsigned long last_pfn,
-                                  unsigned long *ei_startpfn,
-                                  unsigned long *ei_endpfn)
-{
-        u64 align = PAGE_SIZE;
-
-        *ei_startpfn = round_up(ei->base, align) >> PAGE_SHIFT;
-        *ei_endpfn = round_down(ei->base + ei->size, align) >> PAGE_SHIFT;
-
-        /* Skip map entries smaller than a page */
-        if (*ei_startpfn >= *ei_endpfn)
-                return 0;
-
-        /* Skip if map is outside the node */
-        if (*ei_endpfn <= start_pfn || *ei_startpfn >= last_pfn)
-                return 0;
-
-        /* Check for overlaps */
-        if (*ei_startpfn < start_pfn)
-                *ei_startpfn = start_pfn;
-        if (*ei_endpfn > last_pfn)
-                *ei_endpfn = last_pfn;
-
-        return 1;
-}
-
-/*
- * Find the hole size (in bytes) in the memory range.
- * @start: starting address of the memory range to scan
- * @end: ending address of the memory range to scan
- */
-u64 __init memblock_x86_hole_size(u64 start, u64 end)
-{
-        unsigned long start_pfn = start >> PAGE_SHIFT;
-        unsigned long last_pfn = end >> PAGE_SHIFT;
-        unsigned long ei_startpfn, ei_endpfn, ram = 0;
-        struct memblock_region *r;
-
-        for_each_memblock(memory, r)
-                if (memblock_x86_find_active_region(r, start_pfn, last_pfn,
-                                           &ei_startpfn, &ei_endpfn))
-                        ram += ei_endpfn - ei_startpfn;
-
-        return end - start - ((u64)ram << PAGE_SHIFT);
-}
diff --git a/arch/x86/mm/numa.c b/arch/x86/mm/numa.c
index f4a40bdb2e4e..88e562729967 100644
--- a/arch/x86/mm/numa.c
+++ b/arch/x86/mm/numa.c
@@ -475,8 +475,8 @@ static bool __init numa_meminfo_cover_memory(const struct numa_meminfo *mi)
                         numaram = 0;
         }
 
-        e820ram = max_pfn - (memblock_x86_hole_size(0,
-                                        PFN_PHYS(max_pfn)) >> PAGE_SHIFT);
+        e820ram = max_pfn - absent_pages_in_range(0, max_pfn);
+
         /* We seem to lose 3 pages somewhere. Allow 1M of slack. */
         if ((s64)(e820ram - numaram) >= (1 << (20 - PAGE_SHIFT))) {
                 printk(KERN_ERR "NUMA: nodes only cover %LuMB of your %LuMB e820 RAM. Not used.\n",
diff --git a/arch/x86/mm/numa_emulation.c b/arch/x86/mm/numa_emulation.c
index e3d471c20cdc..971fe70549b3 100644
--- a/arch/x86/mm/numa_emulation.c
+++ b/arch/x86/mm/numa_emulation.c
@@ -28,6 +28,16 @@ static int __init emu_find_memblk_by_nid(int nid, const struct numa_meminfo *mi)
         return -ENOENT;
 }
 
+static u64 mem_hole_size(u64 start, u64 end)
+{
+        unsigned long start_pfn = PFN_UP(start);
+        unsigned long end_pfn = PFN_DOWN(end);
+
+        if (start_pfn < end_pfn)
+                return PFN_PHYS(absent_pages_in_range(start_pfn, end_pfn));
+        return 0;
+}
+
 /*
  * Sets up nid to range from @start to @end.  The return value is -errno if
  * something went wrong, 0 otherwise.
@@ -89,7 +99,7 @@ static int __init split_nodes_interleave(struct numa_meminfo *ei,
          * Calculate target node size.  x86_32 freaks on __udivdi3() so do
          * the division in ulong number of pages and convert back.
          */
-        size = max_addr - addr - memblock_x86_hole_size(addr, max_addr);
+        size = max_addr - addr - mem_hole_size(addr, max_addr);
         size = PFN_PHYS((unsigned long)(size >> PAGE_SHIFT) / nr_nodes);
 
         /*
@@ -135,8 +145,7 @@ static int __init split_nodes_interleave(struct numa_meminfo *ei,
                          * Continue to add memory to this fake node if its
                          * non-reserved memory is less than the per-node size.
                          */
-                        while (end - start -
-                               memblock_x86_hole_size(start, end) < size) {
+                        while (end - start - mem_hole_size(start, end) < size) {
                                 end += FAKE_NODE_MIN_SIZE;
                                 if (end > limit) {
                                         end = limit;
@@ -150,7 +159,7 @@ static int __init split_nodes_interleave(struct numa_meminfo *ei,
                          * this one must extend to the boundary.
                          */
                         if (end < dma32_end && dma32_end - end -
-                            memblock_x86_hole_size(end, dma32_end) < FAKE_NODE_MIN_SIZE)
+                            mem_hole_size(end, dma32_end) < FAKE_NODE_MIN_SIZE)
                                 end = dma32_end;
 
                         /*
@@ -158,8 +167,7 @@ static int __init split_nodes_interleave(struct numa_meminfo *ei,
                          * next node, this one must extend to the end of the
                          * physical node.
                          */
-                        if (limit - end -
-                            memblock_x86_hole_size(end, limit) < size)
+                        if (limit - end - mem_hole_size(end, limit) < size)
                                 end = limit;
 
                         ret = emu_setup_memblk(ei, pi, nid++ % nr_nodes,
@@ -180,7 +188,7 @@ static u64 __init find_end_of_node(u64 start, u64 max_addr, u64 size)
 {
         u64 end = start + size;
 
-        while (end - start - memblock_x86_hole_size(start, end) < size) {
+        while (end - start - mem_hole_size(start, end) < size) {
                 end += FAKE_NODE_MIN_SIZE;
                 if (end > max_addr) {
                         end = max_addr;
@@ -211,8 +219,7 @@ static int __init split_nodes_size_interleave(struct numa_meminfo *ei,
          * creates a uniform distribution of node sizes across the entire
          * machine (but not necessarily over physical nodes).
          */
-        min_size = (max_addr - addr - memblock_x86_hole_size(addr, max_addr)) /
-                                                MAX_NUMNODES;
+        min_size = (max_addr - addr - mem_hole_size(addr, max_addr)) / MAX_NUMNODES;
         min_size = max(min_size, FAKE_NODE_MIN_SIZE);
         if ((min_size & FAKE_NODE_MIN_HASH_MASK) < min_size)
                 min_size = (min_size + FAKE_NODE_MIN_SIZE) &
@@ -252,7 +259,7 @@ static int __init split_nodes_size_interleave(struct numa_meminfo *ei,
                          * this one must extend to the boundary.
                          */
                         if (end < dma32_end && dma32_end - end -
-                            memblock_x86_hole_size(end, dma32_end) < FAKE_NODE_MIN_SIZE)
+                            mem_hole_size(end, dma32_end) < FAKE_NODE_MIN_SIZE)
                                 end = dma32_end;
 
                         /*
@@ -260,8 +267,7 @@ static int __init split_nodes_size_interleave(struct numa_meminfo *ei,
                          * next node, this one must extend to the end of the
                          * physical node.
                          */
-                        if (limit - end -
-                            memblock_x86_hole_size(end, limit) < size)
+                        if (limit - end - mem_hole_size(end, limit) < size)
                                 end = limit;
 
                         ret = emu_setup_memblk(ei, pi, nid++ % MAX_NUMNODES,