linux-toradex.git/arch/powerpc/kernel/head_32.S, branch v4.2.7

powerpc: Call do_page_fault() with interrupts off

2012-03-08T23:55:08+00:00

We currently turn interrupts back to their previous state before
calling do_page_fault(). This can be annoying when debugging as
a bad fault will potentially have lost some processor state before
getting into the debugger.

We also end up calling some generic code with interrupts enabled
such as notify_page_fault() with interrupts enabled, which could
be unexpected.

This changes our code to behave more like other architectures,
and make the assembly entry code call into do_page_faults() with
interrupts disabled. They are conditionally re-enabled from
within do_page_fault() in the same spot x86 does it.

While there, add the might_sleep() test in the case of a successful
trylock of the mmap semaphore, again like x86.

Also fix a bug in the existing assembly where r12 (_MSR) could get
clobbered by C calls (the DTL accounting in the exception common
macro and DISABLE_INTS) in some cases.

Signed-off-by: Benjamin Herrenschmidt 
---

v2. Add the r12 clobber fix

powerpc/32: Pass device tree address as u64 to machine_init

2011-09-19T23:19:47+00:00

u64 is used rather than phys_addr_t to keep things simple, as
this is called from assembly code.

Update callers to pass a 64-bit address in r3/r4.  Other unused
register assignments that were once parameters to machine_init
are dropped.

For FSL BookE, look up the physical address of the device tree from the
effective address passed in r3 by the loader.  This is required for
situations where memory does not start at zero (due to AMP or IOMMU-less
virtualization), and thus the IMA doesn't start at zero, and thus the
device tree effective address does not equal the physical address.

Signed-off-by: Scott Wood 
Signed-off-by: Benjamin Herrenschmidt

powerpc: Remove last piece of GEMINI

2011-05-19T07:32:29+00:00

It seems that Adrian is getting old. He removed almost everything of
GEMINI in commit c53653130 ("[POWERPC] Remove the broken Gemini
support") except this piece.

Signed-off-by: Sebastian Andrzej Siewior 
Signed-off-by: Benjamin Herrenschmidt

powerpc/smp: Make start_secondary_resume available to all CPU variants

2011-05-19T03:07:12+00:00

This should fix SMP & Hotplug builds on FSL BookE and 476

Signed-off-by: Benjamin Herrenschmidt

powerpc/smp: soft-replugged CPUs must go back to start_secondary

2011-04-01T04:37:09+00:00

Various thing are torn down when a CPU is hot-unplugged. That CPU
is expected to go back to start_secondary when re-plugged to re
initialize everything, such as clock sources, maps, ...

Some implementations just return from cpu_die() callback
in the idle loop when the CPU is "re-plugged". This is not enough.

We fix it using a little asm trampoline which resets the stack
and calls back into start_secondary as if we were all fresh from
boot. The trampoline already existed on ppc64, but we add it for
ppc32

Signed-off-by: Benjamin Herrenschmidt

KVM: PPC: Add KVM intercept handlers

2010-05-17T09:18:52+00:00

When an interrupt occurs we don't know yet if we're in guest context or
in host context. When in guest context, KVM needs to handle it.

So let's pull the same trick we did on Book3S_64: Just add a macro to
determine if we're in guest context or not and if so jump on to KVM code.

CC: Benjamin Herrenschmidt 
Signed-off-by: Alexander Graf 
Acked-by: Benjamin Herrenschmidt 
Signed-off-by: Avi Kivity

powerpc: gamecube/wii: early debugging using usbgecko

2009-12-13T05:24:31+00:00

Add support for using the USB Gecko adapter as an early debugging
console on the Nintendo GameCube and Wii video game consoles.
The USB Gecko is a 3rd party memory card interface adapter that provides
a EXI (External Interface) to USB serial converter.

Signed-off-by: Albert Herranz 
Acked-by: Benjamin Herrenschmidt 
Signed-off-by: Grant Likely

powerpc: Use names rather than numbers for SPRGs (v2)

2009-08-20T00:12:27+00:00

The kernel uses SPRG registers for various purposes, typically in
low level assembly code as scratch registers or to hold per-cpu
global infos such as the PACA or the current thread_info pointer.

We want to be able to easily shuffle the usage of those registers
as some implementations have specific constraints realted to some
of them, for example, some have userspace readable aliases, etc..
and the current choice isn't always the best.

This patch should not change any code generation, and replaces the
usage of SPRN_SPRGn everywhere in the kernel with a named replacement
and adds documentation next to the definition of the names as to
what those are used for on each processor family.

The only parts that still use the original numbers are bits of KVM
or suspend/resume code that just blindly needs to save/restore all
the SPRGs.

Signed-off-by: Benjamin Herrenschmidt

powerpc: Map more memory early on 601 processors

2009-06-26T04:37:25+00:00

The 32-bit kernel relies on some memory being mapped covering
the kernel text,data and bss at least, early during boot before
the full MMU setup is done. On 32-bit "classic" processors, this
is done using BAT registers.

On 601, the size of BATs is limited to 8M and we use 2 of them
for that initial mapping. This can become quite tight when enabling
features like lockdep, so let's use a 3rd one to bump that mapping
from 16M to 24M. We keep the 4th BAT free as it can be useful for
debugging early boot code to map things like serial ports.

Signed-off-by: Benjamin Herrenschmidt

powerpc: Fix bug in move of altivec code to vector.S

2009-06-12T06:51:41+00:00

The patch that moved to vector.S and made common between 32 and 64-bit the
altivec code had a nasty bug on 32-bit (did I really test that ?) which
causes the kernel to blr back into userspace ... oops :-)

Signed-off-by: Benjamin Herrenschmidt