In order to initialize the serial console early, the atmel_serial
driver had to do a hack where it compared the physical address of the
port with an address known to be permanently mapped, and used it as a
virtual address. This got around the limitation that ioremap() isn't
always available when the console is being initalized.
This patch removes that hack and replaces it with a new "regs" field
in struct atmel_uart_data that the board-specific code can initialize
to a fixed virtual mapping for platform devices where this is possible.
It also initializes the DBGU's regs field with the address the driver
used to check against.
On AVR32, the "regs" field is initialized from the physical base
address when this it can be accessed through a permanently 1:1 mapped
segment, i.e. the P4 segment.
If regs is NULL, the console initialization is delayed until the "real"
driver is up and running and ioremap() can be used.
Signed-off-by: Haavard Skinnemoen <hskinnemoen@atmel.com>
Acked-by: Andrew Victor <andrew@sanpeople.com>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* master.kernel.org:/pub/scm/linux/kernel/git/davej/configh:
Remove all inclusions of <linux/config.h>
Manually resolved trivial path conflicts due to removed files in
the sound/oss/ subdirectory.
* master.kernel.org:/pub/scm/linux/kernel/git/willy/parisc-2.6: (41 commits)
[PARISC] Kill wall_jiffies use
[PARISC] Honour "panic_on_oops" sysctl
[PARISC] Fix fs/binfmt_som.c
[PARISC] Export clear_user_page to modules
[PARISC] Make DMA routines more stubby
[PARISC] Define pci_get_legacy_ide_irq
[PARISC] Fix CONFIG_DEBUG_SPINLOCK
[PARISC] Fix HPUX compat compile with current GCC
[PARISC] Fix iounmap compile warning
[PARISC] Add support for Quicksilver AGPGART
[PARISC] Move LBA and SBA register defines to the common ropes.h
[PARISC] Create shared <asm/ropes.h> header
[PARISC] Stash the lba_device in its struct device drvdata
[PARISC] Generalize IS_ASTRO et al to take a parisc_device like
[PARISC] Pretty print the name of the lba type on kernel boot
[PARISC] Remove some obsolete comments and I checked that Reo is similar to Ike
[PARISC] Add hardware found in the rp8400
[PARISC] Allow nested interrupts
[PARISC] Further updates to timer_interrupt()
[PARISC] remove halftick and copy clocktick to local var (gcc can optimize usage)
...
* git://git.kernel.org/pub/scm/linux/kernel/git/paulus/powerpc: (25 commits)
[POWERPC] Add support for the mpc832x mds board
[POWERPC] Add initial support for the e300c2 core
[POWERPC] Add MPC8360EMDS default dts file
[POWERPC] Add MPC8360EMDS board support
[POWERPC] Add QUICC Engine (QE) infrastructure
[POWERPC] Add QE device tree node definition
[POWERPC] Don't try to just continue if xmon has no input device
[POWERPC] Fix a printk in pseries_mpic_init_IRQ
[POWERPC] Get default baud rate in udbg_scc
[POWERPC] Fix zImage.coff on oldworld PowerMac
[POWERPC] Fix xmon=off and cleanup xmon initialisation
[POWERPC] Cleanup include/asm-powerpc/xmon.h
[POWERPC] Update swim3 printk after blkdev.h change
[POWERPC] Cell interrupt rework
POWERPC: mpc82xx merge: board-specific/platform stuff(resend)
POWERPC: 8272ads merge to powerpc: common stuff
POWERPC: Added devicetree for mpc8272ads board
[POWERPC] iSeries has no legacy I/O
[POWERPC] implement BEGIN/END_FW_FTR_SECTION
[POWERPC] iSeries does not need pcibios_fixup_resources
...
If you lose the x bit (eg: by using patch(1)), powerpc won't build. Be
defensive about it...
Cc: Paul Mackerras <paulus@samba.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This moves the declarations for the architecture helpers into
include/linux/htirq.h from the generic include/linux/pci.h. Hopefully this
will make this distinction clearer.
htirq.h is included where it is needed.
The dependency on the msi code is fixed and removed.
The Makefile is tidied up.
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Andi Kleen <ak@suse.de>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Greg KH <greg@kroah.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This is just a few makefile tweaks and some file renames.
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Andi Kleen <ak@suse.de>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Greg KH <greg@kroah.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
It turns out msi_ops was simply not enough to abstract the architecture
specific details of msi. So I have moved the resposibility of constructing
the struct irq_chip to the architectures, and have two architecture specific
functions arch_setup_msi_irq, and arch_teardown_msi_irq.
For simple architectures those functions can do all of the work. For
architectures with platform dependencies they can call into the appropriate
platform code.
With this msi.c is finally free of assuming you have an apic, and this
actually takes less code.
The helpers for the architecture specific code are declared in the linux/msi.h
to keep them separate from the msi functions used by drivers in linux/pci.h
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Andi Kleen <ak@suse.de>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Greg KH <greg@kroah.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This patch implements two functions ht_create_irq and ht_destroy_irq for
use by drivers. Several other functions are implemented as helpers for
arch specific irq_chip handlers.
The driver for the card I tested this on isn't yet ready to be merged.
However this code is and hypertransport irqs are in use in a few other
places in the kernel. Not that any of this will get merged before 2.6.19
Because the ipath-ht400 is slightly out of spec this code will need to be
generalized to work there.
I think all of the powerpc uses are for a plain interrupt controller in a
chipset so support for native hypertransport devices is a little less
interesting.
However I think this is a half way decent model on how to separate arch
specific and generic helper code, and I think this is a functional model of
how to get the architecture dependencies out of the msi code.
[akpm@osdl.org: Kconfig fix]
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Cc: Greg KH <greg@kroah.com>
Cc: Andi Kleen <ak@muc.de>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This adds defines for the hypertransport capability subtypes and starts
using them a little.
[akpm@osdl.org: fix typo]
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Greg KH <greg@kroah.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
With more irqs in the system we don't need this.
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Rajesh Shah <rajesh.shah@intel.com>
Cc: Andi Kleen <ak@muc.de>
Cc: "Protasevich, Natalie" <Natalie.Protasevich@UNISYS.com>
Cc: "Luck, Tony" <tony.luck@intel.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
After raising the number of irqs the system supports this function is no
longer necessary.
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Rajesh Shah <rajesh.shah@intel.com>
Cc: Andi Kleen <ak@muc.de>
Cc: "Protasevich, Natalie" <Natalie.Protasevich@UNISYS.com>
Cc: "Luck, Tony" <tony.luck@intel.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This refactors the irq handling code to make the vectors a per cpu resource so
the same vector number can be simultaneously used on multiple cpus for
different irqs.
This should make systems that were hitting limits on the total number of irqs
much more livable.
[akpm@osdl.org: build fix]
[akpm@osdl.org: __target_IO_APIC_irq is unneeded on UP]
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Rajesh Shah <rajesh.shah@intel.com>
Cc: Andi Kleen <ak@muc.de>
Cc: "Protasevich, Natalie" <Natalie.Protasevich@UNISYS.com>
Cc: "Luck, Tony" <tony.luck@intel.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This is a small pessimization but it paves the way for making this information
per cpu. Which allows the the maximum number of IRQS to become NR_CPUS*224.
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Rajesh Shah <rajesh.shah@intel.com>
Cc: Andi Kleen <ak@muc.de>
Cc: "Protasevich, Natalie" <Natalie.Protasevich@UNISYS.com>
Cc: "Luck, Tony" <tony.luck@intel.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This patch removes the change in behavior of the irq allocation code when
CONFIG_PCI_MSI is defined. Removing all instances of the assumption that irq
== vector.
create_irq is rewritten to first allocate a free irq and then to assign that
irq a vector.
assign_irq_vector is made static and the AUTO_ASSIGN case which allocates an
vector not bound to an irq is removed.
The ioapic vector methods are removed, and everything now works with irqs.
The definition of NR_IRQS no longer depends on CONFIG_PCI_MSI
[akpm@osdl.org: cleanup]
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Rajesh Shah <rajesh.shah@intel.com>
Cc: Andi Kleen <ak@muc.de>
Cc: "Protasevich, Natalie" <Natalie.Protasevich@UNISYS.com>
Cc: "Luck, Tony" <tony.luck@intel.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This patch removes the change in behavior of the irq allocation code when
CONFIG_PCI_MSI is defined. Removing all instances of the assumption that irq
== vector.
create_irq is rewritten to first allocate a free irq and then to assign that
irq a vector.
assign_irq_vector is made static and the AUTO_ASSIGN case which allocates an
vector not bound to an irq is removed.
The ioapic vector methods are removed, and everything now works with irqs.
The definition of NR_IRQS no longer depends on CONFIG_PCI_MSI
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Rajesh Shah <rajesh.shah@intel.com>
Cc: Andi Kleen <ak@muc.de>
Cc: "Protasevich, Natalie" <Natalie.Protasevich@UNISYS.com>
Cc: "Luck, Tony" <tony.luck@intel.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This removes the hardcoded assumption that irq == vector in the msi
composition code, and it allows the msi message composition to setup logical
mode, or lowest priorirty delivery mode as we do for other apic interrupts,
and with the same selection criteria.
Basically this moves the problem of what is in the msi message into the
architecture irq management code where it belongs. Not in a generic layer
that doesn't have enough information to compose msi messages properly.
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Rajesh Shah <rajesh.shah@intel.com>
Cc: Andi Kleen <ak@muc.de>
Cc: "Protasevich, Natalie" <Natalie.Protasevich@UNISYS.com>
Cc: "Luck, Tony" <tony.luck@intel.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This removes the hardcoded assumption that irq == vector in the msi
composition code, and it allows the msi message composition to setup logical
mode, or lowest priorirty delivery mode as we do for other apic interrupts,
and with the same selection criteria.
Basically this moves the problem of what is in the msi message into the
architecture irq management code where it belongs. Not in a generic layer
that doesn't have enough information to compose msi messages properly.
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Rajesh Shah <rajesh.shah@intel.com>
Cc: Andi Kleen <ak@muc.de>
Cc: "Protasevich, Natalie" <Natalie.Protasevich@UNISYS.com>
Cc: "Luck, Tony" <tony.luck@intel.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
The current implementation of create_irq() is a hack but it is the current
hack that msi.c uses, and unfortunately the ``generic'' apic msi ops depend on
this hack. Thus we are this hack of assuming irq == vector until the
depencencies in the generic irq code are removed.
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Rajesh Shah <rajesh.shah@intel.com>
Cc: Andi Kleen <ak@muc.de>
Cc: "Protasevich, Natalie" <Natalie.Protasevich@UNISYS.com>
Cc: "Luck, Tony" <tony.luck@intel.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
The current implementation of create_irq() is a hack but it is the current
hack that msi.c uses, and unfortunately the ``generic'' apic msi ops depend on
this hack. Thus we are stuck this hack of assuming irq == vector until the
depencencies in the generic msi code are removed.
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Rajesh Shah <rajesh.shah@intel.com>
Cc: Andi Kleen <ak@muc.de>
Cc: "Protasevich, Natalie" <Natalie.Protasevich@UNISYS.com>
Cc: "Luck, Tony" <tony.luck@intel.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Currently we attempt to predict how many irqs we will be able to allocate with
msi using pci_vector_resources and some complicated accounting, and then we
only allow each device as many irqs as we think are available on average.
Only the s2io driver even takes advantage of this feature all other drivers
have a fixed number of irqs they need and bail if they can't get them.
pci_vector_resources is inaccurate if anyone ever frees an irq. The whole
implmentation is racy. The current irq limit policy does not appear to make
sense with current drivers. So I have simplified things. We can revisit this
we we need a more sophisticated policy.
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Rajesh Shah <rajesh.shah@intel.com>
Cc: Andi Kleen <ak@muc.de>
Cc: "Protasevich, Natalie" <Natalie.Protasevich@UNISYS.com>
Cc: "Luck, Tony" <tony.luck@intel.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
In the latest changes the code for migrating x86_64 irqs was dropped. This
reads it in a fashion that will work even if we change the vector on level
triggered irqs when we migrate them.
[akpm@osdl.org: build fix]
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Rajesh Shah <rajesh.shah@intel.com>
Cc: Andi Kleen <ak@muc.de>
Cc: "Protasevich, Natalie" <Natalie.Protasevich@UNISYS.com>
Cc: "Luck, Tony" <tony.luck@intel.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This patch converts all the i386 PIC controllers (except VisWS and Voyager,
which I could not test - but which should still work as old-style IRQ layers)
to the new and simpler irq-chip interrupt handling layer.
[akpm@osdl.org: build fix]
[mingo@elte.hu: enable fasteoi handler for i386 level-triggered IO-APIC irqs]
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Roland Dreier <rolandd@cisco.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This patch converts all the x86_64 PIC controllers layers to the new and
simpler irq-chip interrupt handling layer.
[mingo@elte.hu: The patch also enables the fasteoi handler for x86_64]
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Roland Dreier <rolandd@cisco.com>
Cc: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
wall_jiffies and jiffies are now equal, so this is a noop...
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Kyle McMartin <kyle@parisc-linux.org>
Joel Soete points out that we refer to pa_tlb_lock but only define it if
CONFIG_SMP which breaks a uniprocessor build with CONFIG_DEBUG_SPINLOCK
enabled. No module refers to pa_tlb_lock, so we can delete the export.
Signed-off-by: Matthew Wilcox <willy@parisc-linux.org>
Signed-off-by: Kyle McMartin <kyle@parisc-linux.org>
GCC no longer allows a cast as lvalue; fix the same way fs/readdir.c was
Signed-off-by: Matthew Wilcox <matthew@wil.cx>
Signed-off-by: Kyle McMartin <kyle@parisc-linux.org>
iounmap's argument needs to be both const and volatile, otherwise we'll
get warnings that we're discarding pointer qualifiers
Signed-off-by: Matthew Wilcox <matthew@wil.cx>
Signed-off-by: Kyle McMartin <kyle@parisc-linux.org>
Our prior mode of operation didn't allow nested interrupts
because it makes the interrupt code much simpler. However,
nested interrupts are better for latency.
This code uses the EIEM register to simulate level interrupts
and thus achieve nesting.
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
Signed-off-by: Kyle McMartin <kyle@parisc-linux.org>
This version (relative to the current tree):
o eliminates "while (ticks_elapsed)" loop. It's not needed.
o drop "ticks_elapsed" completely from timer_interrupt().
o Estimates elapsed cycles (based on HZ) to see which kind of
math we want to use to calculate "cycles_remainder".
o Fixes a bug where we would loose a tick if we decided
we wanted to skip one interrupt.
Signed-off-by: Grant Grundler <grundler@parisc-linux.org>
Signed-off-by: Kyle McMartin <kyle@parisc-linux.org>
It's just a bit easier to follow and timer code is complex enough.
So far, only tested on A500-5x (64-bit SMP), ie: gettimeoffset() code
hasn't been tested at all.
Signed-off-by: Grant Grundler <grundler@parisc-linux.org>
Signed-off-by: Kyle McMartin <kyle@parisc-linux.org>
I couldn't find where the itimer was getting started for slave CPUs.
CPU 0 (master) itimer was started in time_init() (arch/parisc/kernel/time.c).
start_cpu_itimer() code was striped from time_init().
Slaves now start their itimer in smp_cpu_init().
This is a first step towards making gettimeoffset() work for SMP.
Next step will be to determine the CR16 (cycle counter)
offsets for each CPU relative to the master (CPU 0).
Signed-off-by: Grant Grundler <grundler@parisc-linux.org>
Signed-off-by: Kyle McMartin <kyle@parisc-linux.org>
Stop using PER_LINUX32 to designate processes needing
compaterizing. Convert is_compat_task to use TIF_32BIT and
set TIF_32BIT in binfmt_elf32.c
Signed-off-by: Kyle McMartin <kyle@parisc-linux.org>
This patch fixes the pa8800 at a gross level (there are still other
subtle incoherency issues which can still cause crashes and HPMCs).
What it does is try to force eject inequivalent aliases before they
become visible to the L2 cache (which is where we get the incoherence
problems).
A new function (parisc_requires_coherency) is introduced in
asm/processor.h to identify the pa8x00 processors (8800 and 8900)
which have the issue.
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
Signed-off-by: Kyle McMartin <kyle@parisc-linux.org>
Abstract existing shift register left macros as shift register
right are. This lends itself to a nice clean up of some #ifdef
blocks in entry.S
Signed-off-by: Kyle McMartin <kyle@parisc-linux.org>
It seems PA7200 processors also suppress traps on loads to
%r0. This means we can prefetch for read on these cpus. Of course,
we can't support prefetch for write, since that requires
LOAD DOUBLEWORD which was added with PA2.0
Signed-off-by: Kyle McMartin <kyle@parisc-linux.org>