Commit Graph

9 Commits

Author SHA1 Message Date
Michael Neuling
ec249dd860 cxl: Move include file cxl.h -> cxl-base.h
This moves the current include file from cxl.h -> cxl-base.h.  This current
include file is used only to pass information between the base driver that
needs to be built into the kernel and the cxl module.

This is to make way for a new include/misc/cxl.h which will
contain just the kernel API for other driver to use

Signed-off-by: Michael Neuling <mikey@neuling.org>
Acked-by: Ian Munsie <imunsie@au1.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-06-03 13:27:19 +10:00
Michael Neuling
85a97da958 powerpc/copro: Fix faulting kernel segments
This fixes calculating the key bits (KP and KS) in the SLB VSID for kernel
mappings.

I'm not CCing this to stable as there are no uses of this currently.

Signed-off-by: Michael Neuling <mikey@neuling.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-06-03 13:27:15 +10:00
Mel Gorman
842915f566 ppc64: add paranoid warnings for unexpected DSISR_PROTFAULT
ppc64 should not be depending on DSISR_PROTFAULT and it's unexpected if
they are triggered.  This patch adds warnings just in case they are being
accidentally depended upon.

Signed-off-by: Mel Gorman <mgorman@suse.de>
Acked-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Tested-by: Sasha Levin <sasha.levin@oracle.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Dave Jones <davej@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Kirill Shutemov <kirill.shutemov@linux.intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Rik van Riel <riel@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-02-12 18:54:08 -08:00
Linus Torvalds
33692f2759 vm: add VM_FAULT_SIGSEGV handling support
The core VM already knows about VM_FAULT_SIGBUS, but cannot return a
"you should SIGSEGV" error, because the SIGSEGV case was generally
handled by the caller - usually the architecture fault handler.

That results in lots of duplication - all the architecture fault
handlers end up doing very similar "look up vma, check permissions, do
retries etc" - but it generally works.  However, there are cases where
the VM actually wants to SIGSEGV, and applications _expect_ SIGSEGV.

In particular, when accessing the stack guard page, libsigsegv expects a
SIGSEGV.  And it usually got one, because the stack growth is handled by
that duplicated architecture fault handler.

However, when the generic VM layer started propagating the error return
from the stack expansion in commit fee7e49d45 ("mm: propagate error
from stack expansion even for guard page"), that now exposed the
existing VM_FAULT_SIGBUS result to user space.  And user space really
expected SIGSEGV, not SIGBUS.

To fix that case, we need to add a VM_FAULT_SIGSEGV, and teach all those
duplicate architecture fault handlers about it.  They all already have
the code to handle SIGSEGV, so it's about just tying that new return
value to the existing code, but it's all a bit annoying.

This is the mindless minimal patch to do this.  A more extensive patch
would be to try to gather up the mostly shared fault handling logic into
one generic helper routine, and long-term we really should do that
cleanup.

Just from this patch, you can generally see that most architectures just
copied (directly or indirectly) the old x86 way of doing things, but in
the meantime that original x86 model has been improved to hold the VM
semaphore for shorter times etc and to handle VM_FAULT_RETRY and other
"newer" things, so it would be a good idea to bring all those
improvements to the generic case and teach other architectures about
them too.

Reported-and-tested-by: Takashi Iwai <tiwai@suse.de>
Tested-by: Jan Engelhardt <jengelh@inai.de>
Acked-by: Heiko Carstens <heiko.carstens@de.ibm.com> # "s390 still compiles and boots"
Cc: linux-arch@vger.kernel.org
Cc: stable@vger.kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-01-29 10:51:32 -08:00
Ian Munsie
03f5439797 powerpc/mm: Use appropriate ESID mask in copro_calculate_slb()
This patch makes copro_calculate_slb() mask the ESID by the correct mask
for 1T vs 256M segments.

This has no effect by itself as the extra bits were ignored, but it
makes debugging the segment table entries easier and means that we can
directly compare the ESID values for duplicates without needing to worry
about masking in the comparison.

This will be used to simplify a comparison in the following patch.

Signed-off-by: Ian Munsie <imunsie@au1.ibm.com>
Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2014-10-28 19:52:45 +11:00
Ian Munsie
4c6d9acce1 powerpc/mm: Add hooks for cxl
This adds hooks into the core powerpc mm code for cxl.

The core powerpc code sometimes uses local tlbie. Unfortunately this won't
work with the current cxl driver as it relies on snooping tlbie broadcasts.

The cxl hardware can have TLB entries invalidated via MMIO but this is not
currently supported by the driver. In future we can make local tlbie smarter so
that it invalidates cxl contexts via MMIO when it needs to but for now we have
this workaround.

This workaround checks for any active cxl contexts and if so, disables local
tlbie.

This also adds a hook for when SLBs are invalidated. This ensures any
corresponding SLBs in cxl are also invalidated at the same time. This is
required for segment demotion.

Signed-off-by: Ian Munsie <imunsie@au1.ibm.com>
Signed-off-by: Michael Neuling <mikey@neuling.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2014-10-08 20:15:55 +11:00
Ian Munsie
be3ebfe821 powerpc/cell: Make spu_flush_all_slbs() generic
This moves spu_flush_all_slbs() into a generic call copro_flush_all_slbs().

This will be useful when we add cxl which also needs a similar SLB flush call.

Signed-off-by: Ian Munsie <imunsie@au1.ibm.com>
Signed-off-by: Michael Neuling <mikey@neuling.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2014-10-08 20:15:37 +11:00
Ian Munsie
73d16a6e0e powerpc/cell: Move data segment faulting code out of cell platform
__spu_trap_data_seg() currently contains code to determine the VSID and ESID
required for a particular EA and mm struct.

This code is generically useful for other co-processors. This moves the code of
the cell platform so it can be used by other powerpc code. It also adds 1TB
segment handling which Cell didn't support.  The new function is called
copro_calculate_slb().

This also moves the internal struct spu_slb to a generic struct copro_slb which
is now used in the Cell and copro code.  We use this new struct instead of
passing around esid and vsid parameters.

Signed-off-by: Ian Munsie <imunsie@au1.ibm.com>
Signed-off-by: Michael Neuling <mikey@neuling.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2014-10-08 20:14:55 +11:00
Ian Munsie
e83d016975 powerpc/cell: Move spu_handle_mm_fault() out of cell platform
Currently spu_handle_mm_fault() is in the cell platform.

This code is generically useful for other non-cell co-processors on powerpc.

This patch moves this function out of the cell platform into arch/powerpc/mm so
that others may use it.

Signed-off-by: Ian Munsie <imunsie@au1.ibm.com>
Signed-off-by: Michael Neuling <mikey@neuling.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2014-10-08 20:14:54 +11:00