linux-toradex.git/arch/parisc, branch v3.9.6

parisc: make default cross compiler search more robust (v3)

2013-05-19T18:38:47+00:00

commit 6880b0150a7c25fd75c5ece80abc49ebf53c38c1 upstream.

People/distros vary how they prefix the toolchain name for 64bit builds.
Rather than enforce one convention over another, add a for loop which
does a search for all the general prefixes.

For 64bit builds, we now search for (in order):
	hppa64-unknown-linux-gnu
	hppa64-linux-gnu
	hppa64-linux

For 32bit builds, we look for:
	hppa-unknown-linux-gnu
	hppa-linux-gnu
	hppa-linux
	hppa2.0-unknown-linux-gnu
	hppa2.0-linux-gnu
	hppa2.0-linux
	hppa1.1-unknown-linux-gnu
	hppa1.1-linux-gnu
	hppa1.1-linux

This patch was initiated by Mike Frysinger, with feedback from Jeroen
Roovers, John David Anglin and Helge Deller.

Signed-off-by: Mike Frysinger 
Signed-off-by: Jeroen Roovers 
Signed-off-by: John David Anglin 
Signed-off-by: Helge Deller 
Signed-off-by: Greg Kroah-Hartman

parisc: fix NATIVE set up in build

2013-05-19T18:38:46+00:00

commit 93782eba49e23c3f311a6b05a19ba15927ec4e8b upstream.

The ifeq operator does not accept globs, so this little bit of code will
never match (unless uname literally prints out "parsic*").  Rewrite to
use a pattern matching operator so that NATIVE is set to 1 on parisc.

Signed-off-by: Mike Frysinger 
Signed-off-by: Helge Deller 
Signed-off-by: Greg Kroah-Hartman

parisc: use long branch in fork_like macro

2013-05-19T18:38:46+00:00

commit bbbfde782084b4f0d85ddffb88f1cf4650ff40e4 upstream.

The "b" branch instruction used in the fork_like macro only can handle
17-bit pc-relative offsets.
This fails with an out of range offset with some .config files.
Rewrite to use the "be" instruction which
can branch to any address in a space.

Signed-off-by: John David Anglin  
Signed-off-by: Helge Deller 
Signed-off-by: Greg Kroah-Hartman

parisc: fix SMP races when updating PTE and TLB entries in entry.S

2013-05-19T18:38:45+00:00

commit f0a18819e261afc5fdbd8c5c6f9943123c5461ba upstream.

Currently, race conditions exist in the handling of TLB interruptions in
entry.S.  In particular, dirty bit updates can be lost if an accessed
interruption occurs just after the dirty bit interruption on a different
cpu.  Lost dirty bit updates result in user pages not being flushed and
general system instability.  This change adds lock and unlock macros to
synchronize all PTE and TLB updates done in entry.S.  As a result,
userspace stability is significantly improved.

Signed-off-by: John David Anglin  
Signed-off-by: Helge Deller 
Signed-off-by: Greg Kroah-Hartman

parisc: only re-enable interrupts if we need to schedule or deliver signals when returning to userspace

2013-05-19T18:38:45+00:00

commit c207a76bf155cb5cf24cf849c08f6555e9180594 upstream.

Helge and I have found that we have a kernel stack overflow problem
which causes a variety of random failures.
Currently, we re-enable interrupts when returning from an external
interrupt incase we need to schedule or delivery
signals.  As a result, a potentially unlimited number of interrupts
can occur while we are running on the kernel
stack.  It is very limited in space (currently, 16k).  This change
defers enabling interrupts until we have
actually decided to schedule or delivery signals.  This only occurs
when we about to return to userspace.  This
limits the number of interrupts on the kernel stack to one.  In other
cases, interrupts remain disabled until the
final return from interrupt (rfi).

Signed-off-by: John David Anglin  
Signed-off-by: Helge Deller 
Signed-off-by: Greg Kroah-Hartman

parisc: use spin_lock_irqsave/spin_unlock_irqrestore for PTE updates

2013-04-25T20:37:00+00:00

User applications running on SMP kernels have long suffered from instability
and random segmentation faults.  This patch improves the situation although
there is more work to be done.

One of the problems is the various routines in pgtable.h that update page table
entries use different locking mechanisms, or no lock at all (set_pte_at).  This
change modifies the routines to all use the same lock pa_dbit_lock.  This lock
is used for dirty bit updates in the interruption code. The patch also purges
the TLB entries associated with the PTE to ensure that inconsistent values are
not used after the page table entry is updated.  The UP and SMP code are now
identical.

The change also includes a minor update to the purge_tlb_entries function in
cache.c to improve its efficiency.

Signed-off-by: John David Anglin 
Cc: Helge Deller 
Signed-off-by: Helge Deller

parisc: disable -mlong-calls compiler option for kernel modules

2013-04-25T20:36:50+00:00

CONFIG_MLONGCALLS was introduced in commit
ec758f98328da3eb933a25dc7a2eed01ef44d849 to overcome linker issues when linking
huge linux kernels, e.g. with many modules linked in.

But in the kernel module loader there is no support yet for the new relocation
types, which is why modules built with -mlong-calls can't be loaded.
Furthermore, for modules long calls are not really necessary, since we already
use stub sections which resolve long distance calls.

So, let's just disable this compiler option when compiling kernel modules.

Signed-off-by: Helge Deller

parisc: uaccess: fix compiler warnings caused by __put_user casting

2013-04-25T20:36:42+00:00

When targetting 32-bit processors, __put_user emits a pair of stw
instructions for the 8-byte case. If the type of __val is a pointer, the
marshalling code casts it to the wider integer type of u64, resulting
in the following compiler warnings:

  kernel/signal.c: In function 'copy_siginfo_to_user':
  kernel/signal.c:2752:11: warning: cast from pointer to integer of different size [-Wpointer-to-int-cast]
  kernel/signal.c:2752:11: warning: cast from pointer to integer of different size [-Wpointer-to-int-cast]
  [...]

This patch fixes the warnings by removing the marshalling code and using
the correct output modifiers in the __put_{user,kernel}_asm64 macros
so that GCC will allocate the right registers without the need to
extract the two words explicitly.

Cc: Helge Deller 
Signed-off-by: Will Deacon 
Signed-off-by: Helge Deller

parisc: Change kunmap macro to static inline function

2013-04-25T20:36:31+00:00

Change kunmap macro to static inline function to fix build error
compiling drivers/base/dma-buf.c.

Without the change, the following error can occur:

   CC      drivers/base/dma-buf.o
drivers/base/dma-buf.c: In function 'dma_buf_kunmap':
drivers/base/dma-buf.c:427:46:
error: macro "kunmap" passed 3 arguments, but takes just 1

I believe parisc is the only arch to implement kunmap using a macro.

Signed-off-by: John David Anglin 
Cc: "James E.J. Bottomley" 
Cc: Helge Deller 
Signed-off-by: Helge Deller

parisc: Provide __ucmpdi2 to resolve undefined references in 32 bit builds.

2013-04-25T20:36:15+00:00

The Debian experimental linux source package (3.8.5-1) build fails
with the following errors:
...
MODPOST 2016 modules
ERROR: "__ucmpdi2" [fs/btrfs/btrfs.ko] undefined!
ERROR: "__ucmpdi2" [drivers/md/dm-verity.ko] undefined!

The attached patch resolves this problem.  It is based on the s390
implementation of ucmpdi2.c.

Signed-off-by: John David Anglin 
Cc: "James E.J. Bottomley" 
Signed-off-by: Helge Deller