Based on BenH's earlier work, this is a new version of the EMAC driver
for the built-in ethernet found on PowerPC 4xx embedded CPUs.  The
same ASIC is also found in the Axon bridge chip.  This new version is
designed to work in the arch/powerpc tree, using the device tree to
probe the device, rather than the old and ugly arch/ppc OCP layer.

This driver is designed to sit alongside the old driver (that lies in
drivers/net/ibm_emac and this one in drivers/net/ibm_newemac).  The
old driver is left in place to support arch/ppc until arch/ppc itself
reaches its final demise (not too long now, with luck).

This driver still has a number of things that could do with cleaning
up, but I think they can be fixed up after merging.  Specifically:
	- Should be adjusted to properly use the dma mapping API.
Axon needs this.
	- Probe logic needs reworking, in conjuction with the general
probing code for of_platform devices.  The dependencies here between
EMAC, MAL, ZMII etc. make this complicated.  At present, it usually
works, because we initialize and register the sub-drivers before the
EMAC driver itself, and (being in driver code) runs after the devices
themselves have been instantiated from the device tree.
Signed-off-by: NDavid Gibson <david@gibson.dropbear.id.au>
Signed-off-by: NJeff Garzik <jeff@garzik.org>

Signed-off-by: NDenis Cheng <crquan@gmail.com>
Signed-off-by: NJeff Garzik <jeff@garzik.org>

Maintain a per-CPU global "struct pt_regs *" variable which can be used instead
of passing regs around manually through all ~1800 interrupt handlers in the
Linux kernel.

The regs pointer is used in few places, but it potentially costs both stack
space and code to pass it around.  On the FRV arch, removing the regs parameter
from all the genirq function results in a 20% speed up of the IRQ exit path
(ie: from leaving timer_interrupt() to leaving do_IRQ()).

Where appropriate, an arch may override the generic storage facility and do
something different with the variable.  On FRV, for instance, the address is
maintained in GR28 at all times inside the kernel as part of general exception
handling.

Having looked over the code, it appears that the parameter may be handed down
through up to twenty or so layers of functions.  Consider a USB character
device attached to a USB hub, attached to a USB controller that posts its
interrupts through a cascaded auxiliary interrupt controller.  A character
device driver may want to pass regs to the sysrq handler through the input
layer which adds another few layers of parameter passing.

I've build this code with allyesconfig for x86_64 and i386.  I've runtested the
main part of the code on FRV and i386, though I can't test most of the drivers.
I've also done partial conversion for powerpc and MIPS - these at least compile
with minimal configurations.

This will affect all archs.  Mostly the changes should be relatively easy.
Take do_IRQ(), store the regs pointer at the beginning, saving the old one:

	struct pt_regs *old_regs = set_irq_regs(regs);

And put the old one back at the end:

	set_irq_regs(old_regs);

Don't pass regs through to generic_handle_irq() or __do_IRQ().

In timer_interrupt(), this sort of change will be necessary:

	-	update_process_times(user_mode(regs));
	-	profile_tick(CPU_PROFILING, regs);
	+	update_process_times(user_mode(get_irq_regs()));
	+	profile_tick(CPU_PROFILING);

I'd like to move update_process_times()'s use of get_irq_regs() into itself,
except that i386, alone of the archs, uses something other than user_mode().

Some notes on the interrupt handling in the drivers:

 (*) input_dev() is now gone entirely.  The regs pointer is no longer stored in
     the input_dev struct.

 (*) finish_unlinks() in drivers/usb/host/ohci-q.c needs checking.  It does
     something different depending on whether it's been supplied with a regs
     pointer or not.

 (*) Various IRQ handler function pointers have been moved to type
     irq_handler_t.
Signed-Off-By: NDavid Howells <dhowells@redhat.com>
(cherry picked from 1b16e7ac850969f38b375e511e3fa2f474a33867 commit)

Signed-off-by: NJörn Engel <joern@wohnheim.fh-wedel.de>
Signed-off-by: NAdrian Bunk <bunk@stusta.de>

Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

This patch replaces current PowerPC 4xx EMAC driver with
new, re-written from the scratch version. This patch is quite big
(~234K) because there is virtualy 0% of common code between old and
new version.

New driver uses NAPI, it solves stability problems under heavy packet
load and low memory, corrects chip register access and fixes numerous
small bugs I don't even remember now.

This patch has been tested on all supported in 2.6 PPC 4xx boards.
It's been used in production for almost a year now on custom
4xx hardware. PPC32 specific parts are already upstream.

Patch was acked by the current EMAC driver maintainer (Matt Porter). I
will be maintaining this new version.
Signed-off-by: NEugene Surovegin <ebs@ebshome.net>
--

 Kconfig                   |   72
 ibm_emac/Makefile         |   13
 ibm_emac/ibm_emac.h       |  418 +++--
 ibm_emac/ibm_emac_core.c  | 3414 ++++++++++++++++++++++++----------------------
 ibm_emac/ibm_emac_core.h  |  313 ++--
 ibm_emac/ibm_emac_debug.c |  377 ++---
 ibm_emac/ibm_emac_debug.h |   63
 ibm_emac/ibm_emac_mal.c   |  674 +++++----
 ibm_emac/ibm_emac_mal.h   |  336 +++-
 ibm_emac/ibm_emac_phy.c   |  335 ++--
 ibm_emac/ibm_emac_phy.h   |  105 -
 ibm_emac/ibm_emac_rgmii.c |  201 ++
 ibm_emac/ibm_emac_rgmii.h |   68
 ibm_emac/ibm_emac_tah.c   |  111 +
 ibm_emac/ibm_emac_tah.h   |   96 -
 ibm_emac/ibm_emac_zmii.c  |  255 +++
 ibm_emac/ibm_emac_zmii.h  |  114 -
 17 files changed, 4114 insertions(+), 2851 deletions(-)
Signed-off-by: NJeff Garzik <jgarzik@pobox.com>

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!