Irq stacks provide an essential protection from stack overflows through
external interrupts, at the cost of two additionals stacks per CPU.

Enable them unconditionally to simplify the kernel build and prevent
people from accidentally disabling them.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

powerpc initializes swiotlb before parsing the kernel boot options so
swiotlb options (e.g. specifying the swiotlb buffer size) are ignored.

Any time before freeing bootmem works for swiotlb so this patch moves
powerpc's swiotlb initialization after parsing the kernel boot
options, mem_init (as x86 does).

Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Tested-by: Becky Bruce <beckyb@kernel.crashing.org>
Tested-by: Albert Herranz <albert_herranz@yahoo.es>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

This enables us to avoid printing swiotlb memory info when we
initialize swiotlb. After swiotlb initialization, we could find
that we don't need swiotlb.

This patch removes the code to print swiotlb memory info in
swiotlb_init() and exports the function to do that.

Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Cc: chrisw@sous-sol.org
Cc: dwmw2@infradead.org
Cc: joerg.roedel@amd.com
Cc: muli@il.ibm.com
Cc: tony.luck@intel.com
Cc: benh@kernel.crashing.org
LKML-Reference: <1257849980-22640-9-git-send-email-fujita.tomonori@lab.ntt.co.jp>
[ -v2: merge up conflict ]
Signed-off-by: Ingo Molnar <mingo@elte.hu>

Remove the reliance on a staticly defined NVRAM size, allowing
platforms to support NVRAMs with sizes differing from the standard.

A fall back value is provided for platforms not supporting this extension.

Signed-off-by: Martyn Welch <martyn.welch@gefanuc.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

Based on initial work from: Dale Farnsworth <dale@farnsworth.org>

Add the low level irq tracing hooks for 32-bit powerpc needed
to enable full lockdep functionality.

The approach taken to deal with the code in entry_32.S is that
we don't trace all the transitions of MSR:EE when we just turn
it off to peek at TI_FLAGS without races. Only when we are
calling into C code or returning from exceptions with a state
that have changed from what lockdep thinks.

There's a little bugger though: If we take an exception that
keeps interrupts enabled (such as an alignment exception) while
interrupts are enabled, we will call trace_hardirqs_on() on the
way back spurriously. Not a big deal, but to get rid of it would
require remembering in pt_regs that the exception was one of the
type that kept interrupts enabled which we don't know at this
stage. (Well, we could test all cases for regs->trap but that
sucks too much).

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Tested-by: Kumar Gala <galak@kernel.crashing.org>

This patch includes the basic infrastructure to use swiotlb
bounce buffering on 32-bit powerpc.  It is not yet enabled on
any platforms.  Probably the most interesting bit is the
addition of addr_needs_map to dma_ops - we need this as
a dma_op because the decision of whether or not an addr
can be mapped by a device is device-specific.

Signed-off-by: Becky Bruce <beckyb@kernel.crashing.org>
Acked-by: Kumar Gala <galak@kernel.crashing.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

Wire up the trampoline code for ppc32 to relay exceptions from the
vectors at address 0 to vectors at address 32MB, and modify Kconfig
to enable Kdump support for all classic powerpcs.

Signed-off-by: Dale Farnsworth <dale@farnsworth.org>
Signed-off-by: Anton Vorontsov <avorontsov@ru.mvista.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>

This makes the MMU context code used for CPUs with no hash table
(except 603) dynamically allocate the various maps used to track
the state of contexts.

Only the main free map and CPU 0 stale map are allocated at boot
time.  Other CPU maps are allocated when those CPUs are brought up
and freed if they are unplugged.

This also moves the initialization of the MMU context management
slightly later during the boot process, which should be fine as
it's really only needed when userland if first started anyways.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Acked-by: Kumar Gala <galak@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>

We're soon running out of CPU features and I need to add some new
ones for various MMU related bits, so this patch separates the MMU
features from the CPU features.  I moved over the 32-bit MMU related
ones, added base features for MMU type families, but didn't move
over any 64-bit only feature yet.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Acked-by: Kumar Gala <galak@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>

smp_hw_index isn't used on 64-bit, so move it from smp.c to
setup_32.c.

Signed-off-by: Nathan Lynch <ntl@pobox.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>