Patch from Lennert Buytenhek
Switch the users of ixp2000_reg_write that depend on writes being
flushed out of the write buffer by the time that function returns
over to ixp2000_reg_wrb.
When using XCB=101, writes to the same functional unit are still
guaranteed to complete in order, so we only need to protect against:
- reordering of writes to different functional units
- masking an interrupt and then reenabling the IRQ bit in CPSR
Signed-off-by: Lennert Buytenhek <buytenh@wantstofly.org>
Signed-off-by: Deepak Saxena <dsaxena@plexity.net>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Patch from Lennert Buytenhek
On the ixdp2x00, the slave CPU is currently not allowed to reset itself
for fear that it will do something 'funky' on the PCI bus. This fear is
ungrounded -- the slave CPU is wired up such that a CPU reset will not
cause a PCI bus reset to be done. This patch changes arch_reset() so
that the slave CPU also executes the reset sequence, allowing it to
reboot itself using /sbin/reboot.
Signed-off-by: Lennert Buytenhek <buytenh@wantstofly.org>
Signed-off-by: Deepak Saxena <dsaxena@plexity.net>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Patch from Lennert Buytenhek
The enp2611 version of the ixp2000 netdev driver needs to be able to
access a number of on-board peripherals. ioremap() is not suitable
for this, as that will cause XCB=000 mappings to be done, which will
make the cpu susceptible to crashing on ixp2400 erratum #66. Properly
aligned iotable mappings with MT_IXP2000_DEVICE will cause section
mappings with XCB=101 to be done, which is safe.
Signed-off-by: Lennert Buytenhek <buytenh@wantstofly.org>
Signed-off-by: Deepak Saxena <dsaxena@plexity.net>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Physical addresses are not valid pointers of any sort and should
not be cast to such.
Signed-off-by: Deepak Saxena <dsaxena@plexity.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Patch from Nicolas Pitre
This patch allows for assorted type of cleanups by letting assembly code
use the same set of defines for constant values and avoid duplicated
definitions that might not always be in sync, or that might simply be
confusing due to the different names for the same thing.
Signed-off-by: Nicolas Pitre <nico@cam.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Patch from Lennert Buytenhek
Introduce ixp2000_reg_wrb, which is a variant of ixp2000_reg_write
that does a readback from the target register, to make sure that
the write has been flushed out of the write buffer.
Unlike the previous (ineffective) readback in ixp2000_reg_write, this
readback is followed by an instruction that depends on the value of
the readback so that the CPU actually stalls until the readback has
completed.
Signed-off-by: Lennert Buytenhek <buytenh@wantstofly.org>
Signed-off-by: Deepak Saxena <dsaxena@plexity.net>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Patch from Lennert Buytenhek
Turn ixp2000_reg_read into an inline function.
Signed-off-by: Lennert Buytenhek <buytenh@wantstofly.org>
Signed-off-by: Deepak Saxena <dsaxena@plexity.net>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Patch from Lennert Buytenhek
The workaround that we do for avoiding triggering ixp2400 erratum #66
involves mapping I/O pages using XCB=101 instead of XCB=000 so that we
prevent the I/O signal to the gasket from being asserted (which can
cause data corruption.) But XCB=101 mappings are write-buffered while
mappings using XCB=000 are not, which is why if we use XCB=101 mappings
we do a readback for every CSR store in an attempt to make sure that
the store has been pushed out of the xscale core and the gasket.
Unfortunately, there are two issues with this:
- we do a readback for every CSR store, which is wrong, because the
register we are writing to might have unwanted side-effects on read,
for example, in the case of the scratchpad ring enqueue/dequeue
registers; and
- the readback is totally ineffective in the way we currently do it,
because we just issue a load but do not issue any instruction that
depends on the return value of that load, so the xscale core does
not wait for the load to complete before continuing.
See this linux-arm-kernel mailing list post for further information:
http://lists.arm.linux.org.uk/pipermail/linux-arm-kernel/2005-September/031314.html
This means that my ixp2400 boxes have been running for many months
without a working readback in ixp2000_reg_write, without any apparent
adverse effects. Two of them have been running for a week now with
the actual readback deleted from ixp2000_reg_write, also without any
apparent ill effects.
So, because in its current form it does more harm than good, the
readback in ixp2000_reg_write should simply be killed, as the patch
below does.
Signed-off-by: Lennert Buytenhek <buytenh@wantstofly.org>
Signed-off-by: Deepak Saxena <dsaxena@plexity.net>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Patch from Lennert Buytenhek
We already had a mapping for the msf, but we didn't have any
register definitions for it yet.
Signed-off-by: Lennert Buytenhek <buytenh@wantstofly.org>
Signed-off-by: Deepak Saxena <dsaxena@plexity.net>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Including asm/hardware.h into asm/io.h can cause #define clashes
between platform specific definitions and driver local definitions.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Patch from Lennert Buytenhek
The intel docs call it IXP2000_PRODUCT_ID, and we have a definition
for IXP2000_PRODUCT_ID as well, so IXP2000_PROD_ID can go. It's only
used in one place.
Signed-off-by: Lennert Buytenhek <buytenh@wantstofly.org>
Signed-off-by: Deepak Saxena <dsaxena@plexity.net>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Patch from Lennert Buytenhek
This patch:
- changes the ixp2000_reg_write accessor to take a 'volatile void *'
instead of a 'volatile unsigned long *', which then allows passing in
a u32 * as first argument without being greeted with a warning; and
- adds an ixp2000_reg_read accessor.
We can then use these accessors in ixp2000 code to access on-chip
peripherals, instead of directly dereferencing pointers. This is for
use by the ixp2000 microengine driver which was recently announced on
netdev. We can't use readl/writel on the ixp2000 since it is usually
run in big-endian mode, and on big-endian platforms, readl/writel
perform byteswapping.
A future patch will remove the readback from ixp2000_reg_write, since
it's not needed to prevent erratum #66, and add manual readbacks to the
places that need them (writes are not synchronous since we map in device
space using XCB=101 nowadays), such as interrupt disabling and GPIO
manipulation. See also:
http://lists.arm.linux.org.uk/pipermail/linux-arm-kernel/2005-February/027084.html
Patch has been ACKed by Jeff Garzik.
Signed-off-by: Lennert Buytenhek <buytenh@wantstofly.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Patch from Lennert Buytenhek
This patch converts the ixp2000 serial port over to a platform
serial device.
Signed-off-by: Lennert Buytenhek <buytenh@wantstofly.org>
Signed-off-by: Deepak Saxena <dsaxena@plexity.net>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Patch from Lennert Buytenhek
Add a mapping for the ixp2400 and ixp2800 msf unit. The msf is the
ixp2000's 'media and switch fabric' unit, which handles the networking
part of the chip.
Signed-off-by: Lennert Buytenhek <buytenh@wantstofly.org>
Signed-off-by: Deepak Saxena
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Patch from Lennert Buytenhek
Add a comment to asm/arch-ixp2000/ixp2000-regs.h describing the
ixp2000 virtual memory map layout.
Signed-off-by: Lennert Buytenhek <buytenh@wantstofly.org>
Signed-off-by: Deepak Saxena
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Patch from Lennert Buytenhek
As the ixdp cpld mappings now live at 0xfe000000, we can push
VMALLOC_END upwards to 0xfb000000, where the first iotable mapping
begins.
Signed-off-by: Lennert Buytenhek <buytenh@wantstofly.org>
Signed-off-by: Deepak Saxena
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Patch from Lennert Buytenhek
All ixdp platforms currently have a cpld mapped in at 0xfafff000.
Since this address is not 1M-aligned, a regular page mapping will be
used instead of a section mapping, which opens up the possibility of
triggering ixp2400 erratum #66 as we only do the XCB=101 workaround
thing for section mappings.
There is still a lot of space higher up in the virtual memory map
for 1M mappings, so move the cpld mapping to 0xfe000000 and make it
1M big so that a section mapping will be used for it.
Signed-off-by: Lennert Buytenhek <buytenh@wantstofly.org>
Signed-off-by: Deepak Saxena
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Patch from Lennert Buytenhek
The later ixp2000 models don't need the PCI I/O workaround that we
currently perform. Add a config option to disable the workaround,
and panic on boot if a kernel without the workaround is booted on a
buggy chip. As only pre-production ixp2000s need the workaround,
the default is for it not to be configured in.
Signed-off-by: Lennert Buytenhek <buytenh@wantstofly.org>
Signed-off-by: Deepak Saxena
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Patch from Lennert Buytenhek
A number of ixp2000 models have a bug where the byte lanes for PCI I/O
transactions are swapped. We already work around this in our versions
of {in,out}{b,w,l}, but we also need to perform these workarounds in a
custom implementation of the new iomap API, provided in this patch.
Signed-off-by: Lennert Buytenhek <buytenh@wantstofly.org>
Signed-off-by: Deepak Saxena
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Patch from Lennert Buytenhek
This patch cleans up the ixp2000 gpio irq code and implements the
set_irq_type method for gpio irqs so that users can select for which
events (falling edge/rising edge/level low/level high) on the gpio
pin they want the corresponding gpio irq to be triggered.
Signed-off-by: Lennert Buytenhek <buytenh@wantstofly.org>
Signed-off-by: Deepak Saxena
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Patch from Lennert Buytenhek
Two macros that are used on the ixp2000 to fixup byte lane enables
for I/O space accesses, align{b,w}, use their arguments without
parenthesizing them.
Signed-off-by: Lennert Buytenhek <buytenh@wantstofly.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Patch from Lennert Buytenhek
The IXP2000 has four timers, but if we're on an A-step IXP2800, timer
2 and 3 don't work. We need two timers for timekeeping (one for the
timer interrupt and one for tracking missed jiffies), so on early
IXP2800s we have no other choice but to use timer 1 and 4 for that,
but on all other IXP2000s we'd rather leave timer 4 free since that's
the only timer we can use for the watchdog.
So, on buggy IXP2000s (i.e. the A-step IXP2800) we use timer 4 for
tracking missed jiffies, and on all all non-buggy IXP2000s (i.e.
everything but the A-step IXP2800) we use timer 2.
On a pre-production IXP2800, this patch should print these messages
on boot:
Enabling IXP2800 erratum #25 workaround
Unable to use IXP2000 watchdog due to IXP2800 erratum #25
On any non-buggy IXP2800 (as well as on IXP2400s) you shouldn't see
anything at all, and the watchdog should be usable again.
Signed-off-by: Lennert Buytenhek
Signed-off-by: Deepak Saxena
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Patch from Deepak Saxena
This patch fixes the following warnings:
include/asm/arch/io.h: In function `insw':
include/asm/arch/io.h:78: warning: comparison of distinct pointer types
lacks acast
include/asm/arch/io.h:79: warning: comparison of distinct pointer types
lacks acast
include/asm/arch/io.h: In function `outsw':
include/asm/arch/io.h:103: warning: comparison of distinct pointer types
lacks a cast
include/asm/arch/io.h:104: warning: comparison of distinct pointer types
lacks a cast
include/asm/arch/io.h: In function `inw':
include/asm/arch/io.h:127: warning: comparison of distinct pointer types
lacks a cast
Signed-off-by: Deepak Saxena
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
VMALLOC_START and VMALLOC_OFFSET are common between all ARM
machine classes. Move them into include/asm-arm/pgtable.h,
but allow a machine class to override them if required.
Signed-off-by: Russell King <rmk@arm.linux.org.uk>
Patch from Lennert Buytenhek
Export ixp2000_pci_config_addr, to be used by the IXDP2800 platform
setup code to coordinate booting the master and slave NPU.
Signed-off-by: Lennert Buytenhek
Signed-off-by: Deepak Saxena
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
