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linux/arch/i386/kernel/numaq.c
Dave Hansen e1474e2d9d [PATCH] re-disable TSC on NUMAQ
Somewhere recently, the TSC got re-enabled for timekeeping on NUMAQ
machines.  However, the hardware makes these get unsynchronized quite
badly.  So badly, in fact, that the code to fix up the skew can just hang
on boot.

This patch re-disables them.  It's nicely confined to the numaq.c file.  It
would be great if this could make it into 2.6.13, I think it counts as a
bugfix.

Tested on a 16-proc 4-node NUMAQ.

Signed-off-by: Dave Hansen <haveblue@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-07-28 21:46:05 -07:00

89 lines
2.4 KiB
C

/*
* Written by: Patricia Gaughen, IBM Corporation
*
* Copyright (C) 2002, IBM Corp.
*
* All rights reserved.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
* NON INFRINGEMENT. See the GNU General Public License for more
* details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*
* Send feedback to <gone@us.ibm.com>
*/
#include <linux/config.h>
#include <linux/mm.h>
#include <linux/bootmem.h>
#include <linux/mmzone.h>
#include <linux/module.h>
#include <linux/nodemask.h>
#include <asm/numaq.h>
#include <asm/topology.h>
#include <asm/processor.h>
#define MB_TO_PAGES(addr) ((addr) << (20 - PAGE_SHIFT))
/*
* Function: smp_dump_qct()
*
* Description: gets memory layout from the quad config table. This
* function also updates node_online_map with the nodes (quads) present.
*/
static void __init smp_dump_qct(void)
{
int node;
struct eachquadmem *eq;
struct sys_cfg_data *scd =
(struct sys_cfg_data *)__va(SYS_CFG_DATA_PRIV_ADDR);
nodes_clear(node_online_map);
for_each_node(node) {
if (scd->quads_present31_0 & (1 << node)) {
node_set_online(node);
eq = &scd->eq[node];
/* Convert to pages */
node_start_pfn[node] = MB_TO_PAGES(
eq->hi_shrd_mem_start - eq->priv_mem_size);
node_end_pfn[node] = MB_TO_PAGES(
eq->hi_shrd_mem_start + eq->hi_shrd_mem_size);
memory_present(node,
node_start_pfn[node], node_end_pfn[node]);
node_remap_size[node] = node_memmap_size_bytes(node,
node_start_pfn[node],
node_end_pfn[node]);
}
}
}
/*
* Unlike Summit, we don't really care to let the NUMA-Q
* fall back to flat mode. Don't compile for NUMA-Q
* unless you really need it!
*/
int __init get_memcfg_numaq(void)
{
smp_dump_qct();
return 1;
}
static int __init numaq_dsc_disable(void)
{
printk(KERN_DEBUG "NUMAQ: disabling TSC\n");
tsc_disable = 1;
return 0;
}
core_initcall(numaq_dsc_disable);