Currently, the 32-bit and 64-bit atomic operations on ARM do not
include memory constraints in the inline assembly blocks. In the
case of barrier-less operations [for example, atomic_add], this
means that the compiler may constant fold values which have actually
been modified by a call to an atomic operation.
This issue can be observed in the atomic64_test routine in
<kernel root>/lib/atomic64_test.c:
00000000 <test_atomic64>:
0: e1a0c00d mov ip, sp
4: e92dd830 push {r4, r5, fp, ip, lr, pc}
8: e24cb004 sub fp, ip, #4
c: e24dd008 sub sp, sp, #8
10: e24b3014 sub r3, fp, #20
14: e30d000d movw r0, #53261 ; 0xd00d
18: e3011337 movw r1, #4919 ; 0x1337
1c: e34c0001 movt r0, #49153 ; 0xc001
20: e34a1aa3 movt r1, #43683 ; 0xaaa3
24: e16300f8 strd r0, [r3, #-8]!
28: e30c0afe movw r0, #51966 ; 0xcafe
2c: e30b1eef movw r1, #48879 ; 0xbeef
30: e34d0eaf movt r0, #57007 ; 0xdeaf
34: e34d1ead movt r1, #57005 ; 0xdead
38: e1b34f9f ldrexd r4, [r3]
3c: e1a34f90 strexd r4, r0, [r3]
40: e3340000 teq r4, #0
44: 1afffffb bne 38 <test_atomic64+0x38>
48: e59f0004 ldr r0, [pc, #4] ; 54 <test_atomic64+0x54>
4c: e3a0101e mov r1, #30
50: ebfffffe bl 0 <__bug>
54: 00000000 .word 0x00000000
The atomic64_set (0x38-0x44) writes to the atomic64_t, but the
compiler doesn't see this, assumes the test condition is always
false and generates an unconditional branch to __bug. The rest of the
test is optimised away.
This patch adds suitable memory constraints to the atomic operations on ARM
to ensure that the compiler is informed of the correct data hazards. We have
to use the "Qo" constraints to avoid hitting the GCC anomaly described at
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=44492 , where the compiler
makes assumptions about the writeback in the addressing mode used by the
inline assembly. These constraints forbid the use of auto{inc,dec} addressing
modes, so it doesn't matter if we don't use the operand exactly once.
Cc: stable@kernel.org
Reviewed-by: Nicolas Pitre <nicolas.pitre@linaro.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
The atomic64_add_unless function compares an atomic variable with
a given value and, if they are not equal, adds another given value
to the atomic variable. The function returns zero if the addition
did not occur and non-zero otherwise.
On ARM, the return value is initialised to 1 in C code. Inline assembly
code then performs the atomic64_add_unless operation, setting the
return value to 0 iff the addition does not occur. This means that
when the addition *does* occur, the value of ret must be preserved
across the inline assembly and therefore requires a "+r" constraint
rather than the current one of "=&r".
Thanks to Nicolas Pitre for helping to spot this.
Cc: stable@kernel.org
Reviewed-by: Nicolas Pitre <nicolas.pitre@linaro.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
On i.MX35 the L2X0_AUX_CTRL register does not have sensible reset
default values. Allow them to be overwritten with the aux_val/aux_mask
arguments passed to l2x0_init().
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Check the amp max value at put callbacks and set the upper limit
so that the driver won't write any invalid value over the defined
range.
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Added the beep mixer controls to Conexant codecs.
They simply control the digital beep generator widget.
For cx5047, I couldn't find any beep generator, so it's not implemented
there.
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Propagate changes to upper atm layer, so userspace netmontor knows when DSL
showtime reached.
Signed-off-by: Karl Hiramoto <karl@hiramoto.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
When a signal change event occurs call netif_carrier_on/off.
Signed-off-by: Karl Hiramoto <karl@hiramoto.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Add notifier chain for changes in atm_dev.
Clients like br2684 will call register_atmdevice_notifier() to be notified of
changes. Drivers will call atm_dev_signal_change() to notify clients like
br2684 of the change.
On DSL and ATM devices it's usefull to have a know if you have a carrier
signal. netdevice LOWER_UP changes can be propagated to userspace via netlink
monitor.
Signed-off-by: Karl Hiramoto <karl@hiramoto.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Implement "Unhandled Interrupts" statistic so we can detect when the
hardware tells us that it things we have work to do but we don't find
anything ...
Signed-off-by: Casey Leedom <leedom@chelsio.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Error path in mpc52xx_fec_probe() is broken.
We must free everything that we've allocated.
Signed-off-by: Kulikov Vasiliy <segooon@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
If of_iomap() or irq_of_parse_and_map() fail then np must be freed.
Signed-off-by: Kulikov Vasiliy <segooon@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
If ax_ei_open() failed we must free previously requested irq.
Signed-off-by: Kulikov Vasiliy <segooon@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Many codecs now clear the pin controls at suspend via snd_hda_shutup_pins()
for reducing the click noise at power-off. But this leaves some pins
uninitialized, and they'll be never recovered after resume.
This patch adds the proper recovery of cleared pin controls on resume.
Also it adds a check of bus->shutdown so that pins won't be cleared at
module unloading.
Reference: Kernel bug 16339
http://bugzilla.kernel.org/show_bug.cgi?id=16339
Cc: <stable@kernel.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
This patch removes an unnecessary bank select before resetting the
controller.
Signed-off-by: Richard Röjfors <richard.rojfors@pelagicore.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Currently all code that needs to be run at TX timeout is done in the
calling context, where bottom halves are disabled. Some of the code
blocks, so it needs to be done in a different context. This patch
adds in a work struct which is scheduled at TX timeout. Then the
timeout code is executed within work queue context.
Signed-off-by: Richard Röjfors <richard.rojfors@pelagicore.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Commit eedc765ca4 merged changes from
net-2.6 that added and then removed efx_nic::port_num, which was also
added in net-next-2.6. The end result should be that it is removed,
since it is now unused.
Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Similar to commit 72dccb01e8 (bnx2: Update vlan_features)
In order to enable TSO on vlan devices, tg3 needs to update
dev->vlan_features.
Tested on HP NC326m (aka BCM5715S (rev a3))
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Now core network is able to handle 64 bit netdevice stats on 32 bit
arches, we can provide them for tg3, since hardware maintains 64 bit
counters.
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Now core network is able to handle 64 bit netdevice stats on 32 bit
arches, we can provide them for bnx2, since hardware maintains some 64
bit counters.
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Acked-by: Michael Chan <mchan@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
We can use CONFIG_NEED_DMA_MAP_STATE to see if a platform does real
DMA unmapping.
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Signed-off-by: David S. Miller <davem@davemloft.net>
We could use DEFINE_DMA_UNMAP_ADDR instead but using
CONFIG_NEED_DMA_MAP_STATE is a simpler way to see if a platform does
real DMA unmapping.
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Signed-off-by: David S. Miller <davem@davemloft.net>
When we need to shape traffic using low speeds, we need to
disable tso on network interface :
ethtool -K eth0.2240 tso off
It seems vlan interfaces miss the set_tso() ethtool method.
Before enabling TSO, we must check real device supports
TSO for VLAN-tagged packets and enables TSO.
Note that a TSO change on real device propagates TSO setting
on all vlans, even if admin selected a different TSO setting.
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
If we are soft disabled and receive a doorbell exception we don't process
it immediately. This means we need to check on the way out of irq restore
if there are any doorbell exceptions to process.
The problem is at that point we don't know what our regs are, and that
in turn makes xmon unhappy. To workaround the problem, instead of checking
for and processing doorbells, we check for any doorbells and if there were
any we send ourselves another.
Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
include/asm-generic/irq_regs.h declares per-cpu irq_regs variables and
get_irq_regs() and set_irq_regs() helper functions to maintain them.
These can be used to access the proper pt_regs structure related to the
current interrupt entry (if any).
In the powerpc arch code, this is used to maintain irq regs on
decrementer and external interrupt exceptions. However, for the
doorbell exceptions used by the msgsnd/msgrcv IPI mechanism of newer
BookE CPUs, the irq_regs are not kept up to date.
In particular this means that xmon will not work properly on SMP,
because the secondary xmon instances started by IPI will blow up when
they cannot retrieve the irq regs.
This patch fixes the problem by adding calls to maintain the irq regs
across doorbell exceptions.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Note that critical doorbells are an unimplemented stub just like
other critical or machine check handlers, since we haven't done
support for "levelled" exceptions yet.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
The decrementer on BookE acts as a level interrupt and doesn't
need to be re-triggered when going negative. It doesn't go
negative anyways (unless programmed to auto-reload with a
negative value) as it stops when reaching 0.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
The doorbells use the content of the PIR register to match messages
from other CPUs. This may or may not be the same as our linux CPU
number, so using that as the "target" is no right.
Instead, we sample the PIR register at boot on every processor
and use that value subsequently when sending IPIs.
We also use a per-cpu message mask rather than a global array which
should limit cache line contention.
Note: We could use the CPU number in the device-tree instead of
the PIR register, as they are supposed to be equivalent. This
might prove useful if doorbells are to be used to kick CPUs out
of FW at boot time, thus before we can sample the PIR. This is
however not the case now and using the PIR just works.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Our handling of debug interrupts on Book3E 64-bit is not quite
the way it should be just yet. This is a workaround to let gdb
work at least for now. We ensure that when context switching,
we set the appropriate DBCR0 value for the new task. We also
make sure that we turn off MSR[DE] within the kernel, and set
it as part of the bits that get set when going back to userspace.
In the long run, we will probably set the userspace DBCR0 on the
exception exit code path and ensure we have some proper kernel
value to set on the way into the kernel, a bit like ppc32 does,
but that will take more work.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
This patch makes IPV6 over IPv4 GRE tunnel propagate the transport
class field from the underlying IPV6 header to the IPV4 Type Of Service
field. Without the patch, all IPV6 packets in tunnel look the same to QoS.
This assumes that IPV6 transport class is exactly the same
as IPv4 TOS. Not sure if that is always the case? Maybe need
to mask off some bits.
The mask and shift to get tclass is copied from ipv6/datagram.c
Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Power button is not hot-pluggable so we can save some memory by
using __init.
Signed-off-by: Markus Lehtonen <markus.lehtonen@nokia.com>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
CONFIG_SMP_750 doesn't exist in Kconfig, therefore removing all
references for it from the source code.
Signed-off-by: Christoph Egger <siccegge@cs.fau.de>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Use kstrdup when the goal of an allocation is copy a string into the
allocated region.
The semantic patch that makes this change is as follows:
(http://coccinelle.lip6.fr/)
// <smpl>
@@
expression from,to;
expression flag,E1,E2;
statement S;
@@
- to = kmalloc(strlen(from) + 1,flag);
+ to = kstrdup(from, flag);
... when != \(from = E1 \| to = E1 \)
if (to==NULL || ...) S
... when != \(from = E2 \| to = E2 \)
- strcpy(to, from);
// </smpl>
Signed-off-by: Julia Lawall <julia@diku.dk>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Use kstrdup when the goal of an allocation is copy a string into the
allocated region.
The semantic patch that makes this change is as follows:
(http://coccinelle.lip6.fr/)
// <smpl>
@@
expression from,to;
expression flag,E1,E2;
statement S;
@@
- to = kmalloc(strlen(from) + 1,flag);
+ to = kstrdup(from, flag);
... when != \(from = E1 \| to = E1 \)
if (to==NULL || ...) S
... when != \(from = E2 \| to = E2 \)
- strcpy(to, from);
// </smpl>
Signed-off-by: Julia Lawall <julia@diku.dk>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Form 1 affinity allows multiple entries in ibm,associativity-reference-points
which represent affinity domains in decreasing order of importance. The
Linux concept of a node is always the first entry, but using the other
values as an input to node_distance() allows the memory allocator to make
better decisions on which node to go first when local memory has been
exhausted.
We keep things simple and create an array indexed by NUMA node, capped at
4 entries. Each time we lookup an associativity property we initialise
the array which is overkill, but since we should only hit this path during
boot it didn't seem worth adding a per node valid bit.
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Remove all rcu head inits. We don't care about the RCU head state before
passing it to call_rcu() anyway. Only leave the "on_stack" variants so
debugobjects can keep track of objects on stack.
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Currently the irqs for the i8042, which historically provides keyboard and
mouse (aux) support, is hardwired in the driver rather than parsing the
dts. This patch modifies the powerpc legacy IO code to attempt to parse
the device tree for this information, failing back to the hardcoded values
if it fails.
Signed-off-by: Martyn Welch <martyn.welch@ge.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
At the moment if request_event_sources_irqs() can't allocate or request
the interrupt, it just does a KERN_ERR printk. This may be fine for the
existing RAS code where if we miss an EPOW event it just means that the
event won't be logged and if we miss one of the RAS errors then we could
miss an event that we perhaps should take action on.
But, for the upcoming IO events code that will use event-sources if we
can't allocate or request the interrupt it means we'd potentially miss
an interrupt from the device. So, let's add a WARN_ON() in this error
case so that we're a bit more vocal when something's amiss.
While we're at it, also use pr_err() to neaten the code up a bit.
Signed-off-by: Mark Nelson <markn@au1.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
The RAS code has a #define, RAS_VECTOR_OFFSET, that's used in the
check-exception RTAS call for the vector offset of the exception.
We'll be using this same vector offset for the upcoming IO Event interrupts
code (0x500) so let's move it to include/asm/rtas.h and call it
RTAS_VECTOR_EXTERNAL_INTERRUPT.
Signed-off-by: Mark Nelson <markn@au1.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Now we dynamically allocate the paca array, it takes an extra load
whenever we want to access another cpu's paca. One place we do that a lot
is per cpu variables. A simple example:
DEFINE_PER_CPU(unsigned long, vara);
unsigned long test4(int cpu)
{
return per_cpu(vara, cpu);
}
This takes 4 loads, 5 if you include the actual load of the per cpu variable:
ld r11,-32760(r30) # load address of paca pointer
ld r9,-32768(r30) # load link address of percpu variable
sldi r3,r29,9 # get offset into paca (each entry is 512 bytes)
ld r0,0(r11) # load paca pointer
add r3,r0,r3 # paca + offset
ld r11,64(r3) # load paca[cpu].data_offset
ldx r3,r9,r11 # load per cpu variable
If we remove the ppc64 specific per_cpu_offset(), we get the generic one
which indexes into a statically allocated array. This removes one load and
one add:
ld r11,-32760(r30) # load address of __per_cpu_offset
ld r9,-32768(r30) # load link address of percpu variable
sldi r3,r29,3 # get offset into __per_cpu_offset (each entry 8 bytes)
ldx r11,r11,r3 # load __per_cpu_offset[cpu]
ldx r3,r9,r11 # load per cpu variable
Having all the offsets in one array also helps when iterating over a per cpu
variable across a number of cpus, such as in the scheduler. Before we would
need to load one paca cacheline when calculating each per cpu offset. Now we
have 16 (128 / sizeof(long)) per cpu offsets in each cacheline.
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
