linux/include/asm-x86_64/calgary.h
Jon Mason d2105b10fe [PATCH] x86_64: Calgary IOMMU - Multi-Node NULL pointer dereference fix
Calgary hits a NULL pointer dereference when booting in a multi-chassis
NUMA system.  See Redhat bugzilla number 198498, found by Konrad
Rzeszutek (konradr@redhat.com).

There are many issues that had to be resolved to fix this problem.
Firstly when I originally wrote the code to handle NUMA systems, I
had a large misunderstanding that was not corrected until now.  That was
that I thought the "number of nodes online" referred to number of
physical systems connected.  So that if NUMA was disabled, there
would only be 1 node and it would only show that node's PCI bus.
In reality if NUMA is disabled, the system displays all of the
connected chassis as one node but is only ignorant of the delays
in accessing main memory.  Therefore, references to num_online_nodes()
and MAX_NUMNODES are incorrect and need to be set to the maximum
number of nodes that can be accessed (which are 8).  I created a
variable, MAX_NUM_CHASSIS, and set it to 8 to fix this.

Secondly, when walking the PCI in detect_calgary, the code only
checked the first "slot" when looking to see if a device is present.
This will work for most cases, but unfortunately it isn't always the
case.  In the NUMA MXE drawers, there are USB devices present on the
3rd slot (with slot 1 being empty).  So, to work around this, all
slots (up to 8) are scanned to see if there are any devices present.

Lastly, the bus is being enumerated on large systems in a different
way the we originally thought.  This throws the ugly logic we had
out the window.  To more elegantly handle this, I reorganized the
kva array to be sparse (which removed the need to have any bus number
to kva slot logic in tce.c) and created a secondary space array to
contain the bus number to phb mapping.

With these changes Calgary boots on an x460 with 4 nodes with and
without NUMA enabled.

Signed-off-by: Jon Mason <jdmason@us.ibm.com>
Signed-off-by: Muli Ben-Yehuda <muli@il.ibm.com>
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-07-29 20:59:55 -07:00

63 lines
2.1 KiB
C

/*
* Derived from include/asm-powerpc/iommu.h
*
* Copyright (C) IBM Corporation, 2006
*
* Author: Jon Mason <jdmason@us.ibm.com>
* Author: Muli Ben-Yehuda <muli@il.ibm.com>
*
* 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. 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., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#ifndef _ASM_X86_64_CALGARY_H
#define _ASM_X86_64_CALGARY_H
#include <linux/config.h>
#include <linux/spinlock.h>
#include <linux/device.h>
#include <linux/dma-mapping.h>
#include <asm/types.h>
struct iommu_table {
unsigned long it_base; /* mapped address of tce table */
unsigned long it_hint; /* Hint for next alloc */
unsigned long *it_map; /* A simple allocation bitmap for now */
spinlock_t it_lock; /* Protects it_map */
unsigned int it_size; /* Size of iommu table in entries */
unsigned char it_busno; /* Bus number this table belongs to */
void __iomem *bbar;
u64 tar_val;
struct timer_list watchdog_timer;
};
#define TCE_TABLE_SIZE_UNSPECIFIED ~0
#define TCE_TABLE_SIZE_64K 0
#define TCE_TABLE_SIZE_128K 1
#define TCE_TABLE_SIZE_256K 2
#define TCE_TABLE_SIZE_512K 3
#define TCE_TABLE_SIZE_1M 4
#define TCE_TABLE_SIZE_2M 5
#define TCE_TABLE_SIZE_4M 6
#define TCE_TABLE_SIZE_8M 7
#ifdef CONFIG_CALGARY_IOMMU
extern int calgary_iommu_init(void);
extern void detect_calgary(void);
#else
static inline int calgary_iommu_init(void) { return 1; }
static inline void detect_calgary(void) { return; }
#endif
#endif /* _ASM_X86_64_CALGARY_H */