x86, NUMA: Enable emulation on 32bit too

Now that NUMA init path is unified, NUMA emulation can be enabled on
32bit.  Make numa_emluation.c safe on 32bit by doing the followings.

* Define MAX_DMA32_PFN on 32bit too.

* Include bootmem.h for max_pfn declaration.

* Use u64 explicitly and always use PFN_PHYS() when converting page
  number to address.

* Avoid __udivdi3() generation on 32bit by doing number of pages
  calculation instead in split_nodes_interleave().

And drop X86_64 dependency from Kconfig.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Yinghai Lu <yinghai@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>

1 files changed, 11 insertions, 5 deletions

diff --git a/arch/x86/mm/numa_emulation.c b/arch/x86/mm/numa_emulation.c
index de84cc140379..d0ed086b6247 100644
--- a/arch/x86/mm/numa_emulation.c
+++ b/arch/x86/mm/numa_emulation.c
@@ -5,6 +5,7 @@
 #include <linux/errno.h>
 #include <linux/topology.h>
 #include <linux/memblock.h>
+#include <linux/bootmem.h>
 #include <asm/dma.h>
 
 #include "numa_internal.h"
@@ -84,7 +85,13 @@ static int __init split_nodes_interleave(struct numa_meminfo *ei,
                 nr_nodes = MAX_NUMNODES;
         }
 
-        size = (max_addr - addr - memblock_x86_hole_size(addr, max_addr)) / nr_nodes;
+        /*
+         * 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 = PFN_PHYS((unsigned long)(size >> PAGE_SHIFT) / nr_nodes);
+
         /*
          * Calculate the number of big nodes that can be allocated as a result
          * of consolidating the remainder.
@@ -226,7 +233,7 @@ static int __init split_nodes_size_interleave(struct numa_meminfo *ei,
          */
         while (nodes_weight(physnode_mask)) {
                 for_each_node_mask(i, physnode_mask) {
-                        u64 dma32_end = MAX_DMA32_PFN << PAGE_SHIFT;
+                        u64 dma32_end = PFN_PHYS(MAX_DMA32_PFN);
                         u64 start, limit, end;
                         int phys_blk;
 
@@ -298,7 +305,7 @@ void __init numa_emulation(struct numa_meminfo *numa_meminfo, int numa_dist_cnt)
 {
         static struct numa_meminfo ei __initdata;
         static struct numa_meminfo pi __initdata;
-        const u64 max_addr = max_pfn << PAGE_SHIFT;
+        const u64 max_addr = PFN_PHYS(max_pfn);
         u8 *phys_dist = NULL;
         size_t phys_size = numa_dist_cnt * numa_dist_cnt * sizeof(phys_dist[0]);
         int max_emu_nid, dfl_phys_nid;
@@ -342,8 +349,7 @@ void __init numa_emulation(struct numa_meminfo *numa_meminfo, int numa_dist_cnt)
         if (numa_dist_cnt) {
                 u64 phys;
 
-                phys = memblock_find_in_range(0,
-                                              (u64)max_pfn_mapped << PAGE_SHIFT,
+                phys = memblock_find_in_range(0, PFN_PHYS(max_pfn_mapped),
                                               phys_size, PAGE_SIZE);
                 if (phys == MEMBLOCK_ERROR) {
                         pr_warning("NUMA: Warning: can't allocate copy of distance table, disabling emulation\n");