linux-toradex.git/arch/m68k, branch v3.0.52

m68k: Correct the Atari ALLOWINT definition

2012-08-09T15:27:53+00:00

commit c663600584a596b5e66258cc10716fb781a5c2c9 upstream.

Booting a 3.2, 3.3, or 3.4-rc4 kernel on an Atari using the
`nfeth' ethernet device triggers a WARN_ONCE() in generic irq
handling code on the first irq for that device:

WARNING: at kernel/irq/handle.c:146 handle_irq_event_percpu+0x134/0x142()
irq 3 handler nfeth_interrupt+0x0/0x194 enabled interrupts
Modules linked in:
Call Trace: [<000299b2>] warn_slowpath_common+0x48/0x6a
 [<000299c0>] warn_slowpath_common+0x56/0x6a
 [<00029a4c>] warn_slowpath_fmt+0x2a/0x32
 [<0005b34c>] handle_irq_event_percpu+0x134/0x142
 [<0005b34c>] handle_irq_event_percpu+0x134/0x142
 [<0000a584>] nfeth_interrupt+0x0/0x194
 [<001ba0a8>] schedule_preempt_disabled+0x0/0xc
 [<0005b37a>] handle_irq_event+0x20/0x2c
 [<0005add4>] generic_handle_irq+0x2c/0x3a
 [<00002ab6>] do_IRQ+0x20/0x32
 [<0000289e>] auto_irqhandler_fixup+0x4/0x6
 [<00003144>] cpu_idle+0x22/0x2e
 [<001b8a78>] printk+0x0/0x18
 [<0024d112>] start_kernel+0x37a/0x386
 [<0003021d>] __do_proc_dointvec+0xb1/0x366
 [<0003021d>] __do_proc_dointvec+0xb1/0x366
 [<0024c31e>] _sinittext+0x31e/0x9c0

After invoking the irq's handler the kernel sees !irqs_disabled()
and concludes that the handler erroneously enabled interrupts.

However, debugging shows that !irqs_disabled() is true even before
the handler is invoked, which indicates a problem in the platform
code rather than the specific driver.

The warning does not occur in 3.1 or older kernels.

It turns out that the ALLOWINT definition for Atari is incorrect.

The Atari definition of ALLOWINT is ~0x400, the stated purpose of
that is to avoid taking HSYNC interrupts.  irqs_disabled() returns
true if the 3-bit ipl & 4 is non-zero.  The nfeth interrupt runs at
ipl 3 (it's autovector 3), but 3 & 4 is zero so irqs_disabled() is
false, and the warning above is generated.

When interrupts are explicitly disabled, ipl is set to 7.  When they
are enabled, ipl is masked with ALLOWINT.  On Atari this will result
in ipl = 3, which blocks interrupts at ipl 3 and below.  So how come
nfeth interrupts at ipl 3 are received at all?  That's because ipl
is reset to 2 by Atari-specific code in default_idle(), again with
the stated purpose of blocking HSYNC interrupts.  This discrepancy
means that ipl 3 can remain blocked for longer than intended.

Both default_idle() and falcon_hblhandler() identify HSYNC with
ipl 2, and the "Atari ST/.../F030 Hardware Register Listing" agrees,
but ALLOWINT is defined as if HSYNC was ipl 3.

[As an experiment I modified default_idle() to reset ipl to 3, and
as expected that resulted in all nfeth interrupts being blocked.]

The fix is simple: define ALLOWINT as ~0x500 instead.  This makes
arch_local_irq_enable() consistent with default_idle(), and prevents
the !irqs_disabled() problems for ipl 3 interrupts.

Tested on Atari running in an Aranym VM.

Signed-off-by: Mikael Pettersson 
Tested-by: Michael Schmitz 
Signed-off-by: Geert Uytterhoeven 
Signed-off-by: Greg Kroah-Hartman

m68k: Make sys_atomic_cmpxchg_32 work on classic m68k

2012-08-09T15:27:53+00:00

commit 9e2760d18b3cf179534bbc27692c84879c61b97c upstream.

User space access must always go through uaccess accessors, since on
classic m68k user space and kernel space are completely separate.

Signed-off-by: Andreas Schwab 
Tested-by: Thorsten Glaser 
Signed-off-by: Geert Uytterhoeven 
Signed-off-by: Greg Kroah-Hartman

m68k/mac: Add missing platform check before registering platform devices

2012-04-13T15:14:06+00:00

commit 6cfeba53911d6d2f17ebbd1246893557d5ff5aeb upstream.

On multi-platform kernels, the Mac platform devices should be registered
when running on Mac only. Else it may crash later.

Signed-off-by: Geert Uytterhoeven 
Signed-off-by: Greg Kroah-Hartman

m68k: use kernel processor defines for conditional optimizations

2011-06-14T01:42:29+00:00

Older m68k-linux compilers will include pre-defined symbols that
confuse what processor it is being targeted for. For example gcc-4.1.2
will pre-define __mc68020__ even if you specify the target processor
as -m68000 on the gcc command line. Newer versions of gcc have this
corrected.

In a few places the m68k code uses defined(__mc68020__) for optimizations
that include instructions that are specific to the CPU 68020 and above.
When compiling with older compilers this will be true even when we have
selected to compile for the older 68000 processors.

Switch to using the kernel processor defines, CONFIG_M68020 and friends.

Signed-off-by: Greg Ungerer

m68knommu: create config options for CPU classes

2011-06-14T01:42:29+00:00

There are 3 families of CPU core types that we support in the m68knommu
architecture branch. They are

. traditional 68000
. CPU32 (a 68020 core derivative without MMU or bitfield instructions)
. ColdFire

It will be useful going forward to have a CONFIG_ option defined for
each type. We already have one for ColdFire (CONFIG_COLDFIRE), so add
for the other 2 families, CONFIG_M68000 and CONFIG_MCPU32.

Signed-off-by: Greg Ungerer

m68knommu: fix linker script exported name sections

2011-06-14T01:42:29+00:00

The recent commit titled "module: Sort exported symbols" (f02e8a65)
changed the exported symbol name sections. Bring the m68knommu linker
script into line with those changes - including the sorting of the
symbol names.

Signed-off-by: Greg Ungerer

Merge branch 'setns'

2011-05-28T17:51:01+00:00

* setns:
  ns: Wire up the setns system call

Done as a merge to make it easier to fix up conflicts in arm due to
addition of sendmmsg system call

ns: Wire up the setns system call

2011-05-28T17:48:39+00:00

32bit and 64bit on x86 are tested and working.  The rest I have looked
at closely and I can't find any problems.

setns is an easy system call to wire up.  It just takes two ints so I
don't expect any weird architecture porting problems.

While doing this I have noticed that we have some architectures that are
very slow to get new system calls.  cris seems to be the slowest where
the last system calls wired up were preadv and pwritev.  avr32 is weird
in that recvmmsg was wired up but never declared in unistd.h.  frv is
behind with perf_event_open being the last syscall wired up.  On h8300
the last system call wired up was epoll_wait.  On m32r the last system
call wired up was fallocate.  mn10300 has recvmmsg as the last system
call wired up.  The rest seem to at least have syncfs wired up which was
new in the 2.6.39.

v2: Most of the architecture support added by Daniel Lezcano 
v3: ported to v2.6.36-rc4 by: Eric W. Biederman 
v4: Moved wiring up of the system call to another patch
v5: ported to v2.6.39-rc6
v6: rebased onto parisc-next and net-next to avoid syscall  conflicts.
v7: ported to Linus's latest post 2.6.39 tree.

>  arch/blackfin/include/asm/unistd.h     |    3 ++-
>  arch/blackfin/mach-common/entry.S      |    1 +
Acked-by: Mike Frysinger 

Oh - ia64 wiring looks good.
Acked-by: Tony Luck 

Signed-off-by: Eric W. Biederman 
Signed-off-by: Linus Torvalds

m68knommu: use generic find_next_bit_le()

2011-05-27T00:12:39+00:00

The implementation of find_next_bit_le() on m68knommu is identical with
the generic implementation of find_next_bit_le().

Signed-off-by: Akinobu Mita 
Cc: Greg Ungerer 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

arch: remove CONFIG_GENERIC_FIND_{NEXT_BIT,BIT_LE,LAST_BIT}

2011-05-27T00:12:38+00:00

By the previous style change, CONFIG_GENERIC_FIND_NEXT_BIT,
CONFIG_GENERIC_FIND_BIT_LE, and CONFIG_GENERIC_FIND_LAST_BIT are not used
to test for existence of find bitops anymore.

Signed-off-by: Akinobu Mita 
Acked-by: Greg Ungerer 
Cc: Arnd Bergmann 
Cc: Russell King 
Cc: Martin Schwidefsky 
Cc: Heiko Carstens 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds