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Commit 1b7e03ef authored by Tejun Heo's avatar Tejun Heo
Browse files

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: default avatarTejun 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>
parent 2706a0bf

arch/x86/Kconfig

+1 −1
Original line number Diff line number Diff line
@@ -1201,7 +1201,7 @@ config NODES_SPAN_OTHER_NODES 


config NUMA_EMU

	bool "NUMA emulation"

	depends on X86_64 && NUMA

	depends on NUMA

	---help---

	  Enable NUMA emulation. A flat machine will be split

	  into virtual nodes when booted with "numa=fake=N", where N is the

arch/x86/include/asm/dma.h

+3 −7
Original line number Diff line number Diff line
@@ -72,19 +72,15 @@ 
/* 16MB ISA DMA zone */

#define MAX_DMA_PFN   ((16 * 1024 * 1024) >> PAGE_SHIFT)



#ifdef CONFIG_X86_32

/* 4GB broken PCI/AGP hardware bus master zone */

#define MAX_DMA32_PFN ((4UL * 1024 * 1024 * 1024) >> PAGE_SHIFT)



#ifdef CONFIG_X86_32

/* The maximum address that we can perform a DMA transfer to on this platform */

#define MAX_DMA_ADDRESS      (PAGE_OFFSET + 0x1000000)



#else



/* 4GB broken PCI/AGP hardware bus master zone */

#define MAX_DMA32_PFN ((4UL * 1024 * 1024 * 1024) >> PAGE_SHIFT)



/* Compat define for old dma zone */

#define MAX_DMA_ADDRESS ((unsigned long)__va(MAX_DMA_PFN << PAGE_SHIFT))



#endif



/* 8237 DMA controllers */

arch/x86/mm/numa_emulation.c

+11 −5
Original line number Diff line number Diff line
@@ -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");