Commit e465058d authored by Jon Mason's avatar Jon Mason Committed by Linus Torvalds
Browse files

[PATCH] x86_64: Calgary IOMMU - Calgary specific bits 



This patch hooks Calgary into the build, the x86-64 IOMMU
initialization paths, and introduces the Calgary specific bits.  The
implementation draws inspiration from both PPC (which has support for
the same chip but requires firmware support which we don't have on
x86-64) and gart. Calgary is different from gart in that it support a
translation table per PHB, as opposed to the single gart aperture.

Changes from previous version:
 * Addition of boot-time disablement for bus-level translation/isolation
   (e.g, enable userspace DMA for things like X)
 * Usage of newer IOMMU abstraction functions

Signed-off-by: default avatarMuli Ben-Yehuda <muli@il.ibm.com>
Signed-off-by: default avatarJon Mason <jdmason@us.ibm.com>
Signed-off-by: default avatarAndi Kleen <ak@suse.de>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent 0dc243ae

Documentation/x86_64/boot-options.txt

+21 −0
Original line number Diff line number Diff line
@@ -205,6 +205,27 @@ IOMMU 
  pages  Prereserve that many 128K pages for the software IO bounce buffering.

  force  Force all IO through the software TLB.



  calgary=[64k,128k,256k,512k,1M,2M,4M,8M]

  calgary=[translate_empty_slots]

  calgary=[disable=<PCI bus number>]



    64k,...,8M - Set the size of each PCI slot's translation table

    when using the Calgary IOMMU. This is the size of the translation

    table itself in main memory. The smallest table, 64k, covers an IO

    space of 32MB; the largest, 8MB table, can cover an IO space of

    4GB. Normally the kernel will make the right choice by itself.



    translate_empty_slots - Enable translation even on slots that have

    no devices attached to them, in case a device will be hotplugged

    in the future.



    disable=<PCI bus number> - Disable translation on a given PHB. For

    example, the built-in graphics adapter resides on the first bridge

    (PCI bus number 0); if translation (isolation) is enabled on this

    bridge, X servers that access the hardware directly from user

    space might stop working. Use this option if you have devices that

    are accessed from userspace directly on some PCI host bridge.



Debugging



  oops=panic Always panic on oopses. Default is to just kill the process,

arch/x86_64/Kconfig

+19 −0
Original line number Diff line number Diff line
@@ -405,6 +405,25 @@ config IOMMU 
	  device) unless CONFIG_IOMMU_DEBUG or iommu=force is specified

	  too.



config CALGARY_IOMMU

	bool "IBM Calgary IOMMU support"

	default y

	select SWIOTLB

	depends on PCI && EXPERIMENTAL

	help

	  Support for hardware IOMMUs in IBM's xSeries x366 and x460

	  systems. Needed to run systems with more than 3GB of memory

	  properly with 32-bit PCI devices that do not support DAC

	  (Double Address Cycle). Calgary also supports bus level

	  isolation, where all DMAs pass through the IOMMU.  This

	  prevents them from going anywhere except their intended

	  destination. This catches hard-to-find kernel bugs and

	  mis-behaving drivers and devices that do not use the DMA-API

	  properly to set up their DMA buffers.  The IOMMU can be

	  turned off at boot time with the iommu=off parameter.

	  Normally the kernel will make the right choice by itself.

	  If unsure, say Y.



# need this always selected by IOMMU for the VIA workaround

config SWIOTLB

	bool

arch/x86_64/kernel/Makefile

+1 −0
Original line number Diff line number Diff line
@@ -29,6 +29,7 @@ obj-$(CONFIG_SOFTWARE_SUSPEND) += suspend_asm.o 
obj-$(CONFIG_CPU_FREQ)		+= cpufreq/

obj-$(CONFIG_EARLY_PRINTK)	+= early_printk.o

obj-$(CONFIG_IOMMU)		+= pci-gart.o aperture.o

obj-$(CONFIG_CALGARY_IOMMU)	+= pci-calgary.o tce.o

obj-$(CONFIG_SWIOTLB)		+= pci-swiotlb.o

obj-$(CONFIG_KPROBES)		+= kprobes.o

obj-$(CONFIG_X86_PM_TIMER)	+= pmtimer.o

arch/x86_64/kernel/pci-calgary.c

0 → 100644
+1018 −0

File added.

Preview size limit exceeded, changes collapsed.

arch/x86_64/kernel/pci-dma.c

+9 −0
Original line number Diff line number Diff line
@@ -9,6 +9,7 @@ 
#include <linux/module.h>

#include <asm/io.h>

#include <asm/proto.h>

#include <asm/calgary.h>



int iommu_merge __read_mostly = 0;

EXPORT_SYMBOL(iommu_merge);
@@ -291,6 +292,10 @@ void __init pci_iommu_alloc(void) 
	iommu_hole_init();

#endif



#ifdef CONFIG_CALGARY_IOMMU

	detect_calgary();

#endif



#ifdef CONFIG_SWIOTLB

	pci_swiotlb_init();

#endif
@@ -298,6 +303,10 @@ void __init pci_iommu_alloc(void) 


static int __init pci_iommu_init(void)

{

#ifdef CONFIG_CALGARY_IOMMU

	calgary_iommu_init();

#endif



#ifdef CONFIG_IOMMU

	gart_iommu_init();

#endif

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