linux-toradex.git/arch/powerpc, branch v3.2.3

powerpc: Fix unpaired probe_hcall_entry and probe_hcall_exit

2012-01-12T19:29:23+00:00

commit e4f387d8db3ba3c2dae4d8bdfe7bb5f4fe1bcb0d upstream.

Unpaired calling of probe_hcall_entry and probe_hcall_exit might happen
as following, which could cause incorrect preempt count.

__trace_hcall_entry => trace_hcall_entry -> probe_hcall_entry =>
get_cpu_var => preempt_disable

__trace_hcall_exit => trace_hcall_exit -> probe_hcall_exit =>
put_cpu_var => preempt_enable

where:
A => B and A -> B means A calls B, but
=> means A will call B through function name, and B will definitely be
called.
-> means A will call B through function pointer, so B might not be
called if the function pointer is not set.

So error happens when only one of probe_hcall_entry and probe_hcall_exit
get called during a hcall.

This patch tries to move the preempt count operations from
probe_hcall_entry and probe_hcall_exit to its callers.

Reported-by: Paul E. McKenney 
Signed-off-by: Li Zhong 
Tested-by: Paul E. McKenney 
Signed-off-by: Benjamin Herrenschmidt 
Signed-off-by: Greg Kroah-Hartman

powerpc/time: Handle wrapping of decrementer

2012-01-12T19:29:22+00:00

commit 37fb9a0231ee43d42d069863bdfd567fca2b61af upstream.

When re-enabling interrupts we have code to handle edge sensitive
decrementers by resetting the decrementer to 1 whenever it is negative.
If interrupts were disabled long enough that the decrementer wrapped to
positive we do nothing. This means interrupts can be delayed for a long
time until it finally goes negative again.

While we hope interrupts are never be disabled long enough for the
decrementer to go positive, we have a very good test team that can
drive any kernel into the ground. The softlockup data we get back
from these fails could be seconds in the future, completely missing
the cause of the lockup.

We already keep track of the timebase of the next event so use that
to work out if we should trigger a decrementer exception.

Signed-off-by: Anton Blanchard 
Signed-off-by: Benjamin Herrenschmidt 
Signed-off-by: Greg Kroah-Hartman

procfs: do not confuse jiffies with cputime64_t

2011-12-30T00:31:57+00:00

Commit 2a95ea6c0d129b4 ("procfs: do not overflow get_{idle,iowait}_time
for nohz") did not take into account that one some architectures jiffies
and cputime use different units.

This causes get_idle_time() to return numbers in the wrong units, making
the idle time fields in /proc/stat wrong.

Instead of converting the usec value returned by
get_cpu_{idle,iowait}_time_us to units of jiffies, use the new function
usecs_to_cputime64 to convert it to the correct unit of cputime64_t.

Signed-off-by: Andreas Schwab 
Acked-by: Michal Hocko 
Cc: Arnd Bergmann 
Cc: "Artem S. Tashkinov" 
Cc: Dave Jones 
Cc: Alexey Dobriyan 
Cc: Thomas Gleixner 
Cc: "Luck, Tony" 
Cc: Benjamin Herrenschmidt 
Cc: Martin Schwidefsky 
Cc: Heiko Carstens 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

KVM: PPC: e500: include linux/export.h

2011-12-26T11:28:03+00:00

This is required for THIS_MODULE.  We recently stopped acquiring
it via some other header.

Signed-off-by: Scott Wood 
Signed-off-by: Alexander Graf

KVM: PPC: fix kvmppc_start_thread() for CONFIG_SMP=N

2011-12-26T11:28:02+00:00

Currently kvmppc_start_thread() tries to wake other SMT threads via
xics_wake_cpu().  Unfortunately xics_wake_cpu only exists when
CONFIG_SMP=Y so when compiling with CONFIG_SMP=N we get:

  arch/powerpc/kvm/built-in.o: In function `.kvmppc_start_thread':
  book3s_hv.c:(.text+0xa1e0): undefined reference to `.xics_wake_cpu'

The following should be fine since kvmppc_start_thread() shouldn't
called to start non-zero threads when SMP=N since threads_per_core=1.

Signed-off-by: Michael Neuling 
Signed-off-by: Alexander Graf

KVM: PPC: protect use of kvmppc_h_pr

2011-12-26T11:28:01+00:00

kvmppc_h_pr is only available if CONFIG_KVM_BOOK3S_64_PR.

Signed-off-by: Andreas Schwab 
Signed-off-by: Alexander Graf

KVM: PPC: move compute_tlbie_rb to book3s_64 common header

2011-12-26T11:28:00+00:00

compute_tlbie_rb is only used on ppc64 and cannot be compiled on ppc32.

Signed-off-by: Andreas Schwab 
Signed-off-by: Alexander Graf

powerpc/44x: Add mtd ndfc to the ppx44x defconfig

2011-11-24T23:06:00+00:00

Signed-off-by: Tony Breeds 
Acked-by: Josh Boyer 
Signed-off-by: Benjamin Herrenschmidt

powerpc: Fix compiliation with hugetlbfs enabled

2011-11-24T23:05:59+00:00

arch/powerpc/mm/hugetlbpage.c: In function 'reserve_hugetlb_gpages':
arch/powerpc/mm/hugetlbpage.c:312:2: error: implicit declaration of function 'parse_args'

Signed-off-by: Kumar Gala 
Signed-off-by: Benjamin Herrenschmidt

arch/powerpc/sysdev/ehv_pic.c: add missing kfree

2011-11-24T08:01:24+00:00

At this point, ehv_pic has been allocated but not stored anywhere, so it
should be freed before leaving the function.

A simplified version of the semantic match that finds this problem is as
follows: (http://coccinelle.lip6.fr/)

// 
@exists@
local idexpression x;
statement S,S1;
expression E;
identifier fl;
expression *ptr != NULL;
@@

x = \(kmalloc\|kzalloc\|kcalloc\)(...);
...
if (x == NULL) S
<... when != x
     when != if (...) { <+...kfree(x)...+> }
     when any
     when != true x == NULL
x->fl
...>
(
if (x == NULL) S1
|
if (...) { ... when != x
               when forall
(
 return \(0\|<+...x...+>\|ptr\);
|
* return ...;
)
}
)
// 

Signed-off-by: Julia Lawall 
Acked-by: Timur Tabi 
Signed-off-by: Kumar Gala