Inspired by PowerPC XICS interrupt support code.

All IRQs are virtualized in order to keep NR_IRQS from needing
to be too large.  Interrupts on sparc64 are arbitrary 11-bit
values, but we don't need to define NR_IRQS to 2048 if we
virtualize the IRQs.

As PCI and SBUS controller drivers build device IRQs, we divy
out virtual IRQ numbers incrementally starting at 1.  Zero is
a special virtual IRQ used for the timer interrupt.

So device drivers all see virtual IRQs, and all the normal
interfaces such as request_irq(), enable_irq(), etc. translate
that into a real IRQ number in order to configure the IRQ.

At this point knowledge of the struct ino_bucket is almost
entirely contained within arch/sparc64/kernel/irq.c  There are
a few small bits in the PCI controller drivers that need to
be swept away before we can remove ino_bucket's definition
out of asm-sparc64/irq.h and privately into kernel/irq.c
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

And reuse that struct member for virt_irq, which will
be used in future changesets for the implementation of
mapping between real and virtual IRQ numbers.

This nicely kills off a ton of SBUS and PCI controller
PIL assignment code which is no longer necessary.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Only pil0_dummy_bucket had a pil of zero and we just killed that
off, so we can delete all special case code that used bp->pil==0
as a way to identify a dummy bucket.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This is the first in a series of cleanups that will hopefully
allow a seamless attempt at using the generic IRQ handling
infrastructure in the Linux kernel.

Define PIL_DEVICE_IRQ and vector all device interrupts through
there.

Get rid of the ugly pil0_dummy_{bucket,desc}, instead vector
the timer interrupt directly to a specific handler since the
timer interrupt is the only event that will be signaled on
PIL 14.

The irq_worklist is now in the per-cpu trap_block[].
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

It is already exported by fs/open.c

Noticed by Ben Collins.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Doing PCI config space accesses to non-present PCI slots
can result in fatal JBUS errors if the PCI config access
hypervisor call is performed on cpus other than the boot
cpu.

PCI config space accesses to present PCI slots works just
fine.

Recursively traverse the OBP device tree under the PCI
controller node and record all present device IDs into
a small hash table.

Avoid the hypervisor call for any PCI config space access
attempt for a device not recorded in the hash table.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This makes the debugging information more usable.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Both csum_partial() and the csum_partial_copy*() family of routines
forget to do a final fold on the computed checksum value on sparc64.
So do the standard Sparc "add + set condition codes, add carry"
sequence, then make sure the high 32-bits of the return value are
clear.

Based upon some excellent detective work and debugging done by
Richard Braun and Samuel Thibault.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Uses of smp_processor_id() get pushed earlier and earlier in
the start_kernel() sequence.  So just get it working before
we call start_kernel() to avoid all possible problems.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Using asm-generic/dma-mapping.h does not work because pushing
the call down to pci_alloc_coherent() causes the gfp_t argument
of dma_alloc_coherent() to be ignored.

Fix this by implementing things directly, and adding a gfp_t
argument we can use in the internal call down to the PCI DMA
implementation of pci_alloc_coherent().

This fixes massive memory corruption when using the sound driver
layer, which passes things like __GFP_COMP down into these
routines and (correctly) expects that to work.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Signed-off-by: NDavid S. Miller <davem@davemloft.net>

For sparc32 we need R_SPARC_UA32 relocation support, for
sparc64 we need the handle R_SPARC_DISP32 relocations.

Based upon reports and initial patch by Martin Habets.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Signed-off-by: NDavid S. Miller <davem@davemloft.net>

... it's always current, and that's a good thing - allows simpler locking.
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

A context switch will force a call to flush_tlb_pending() (via
switch_to()), so if we test tlb_nr to be non-zero, then sleep, it
would become zero and later back at the original context we'll pass
zero down into the TLB flushing code which should never see a nr
argument of zero.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Andrew Morton pointed out that compiler might not inline the functions
marked for inline in kprobes.  There-by allowing the insertion of probes
on these kprobes routines, which might cause recursion.

This patch removes all such inline and adds them to kprobes section
there by disallowing probes on all such routines.  Some of the routines
can even still be inlined, since these routines gets executed after the
kprobes had done necessay setup for reentrancy.
Signed-off-by: NPrasanna S Panchamukhi <prasanna@in.ibm.com>
Acked-by: NDavid S. Miller <davem@davemloft.net>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

This patch fixes dependencies of HUGETLB_PAGE_SIZE_64K
Signed-off-by: NJean-Luc Lger <jean-luc.leger@dspnet.fr.eu.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

SYM2 driver uses it.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Signed-off-by: NDavid S. Miller <davem@davemloft.net>

While cleaning up parisc_ksyms.c earlier, I noticed that strpbrk wasn't
being exported from lib/string.c.  Investigating further, I noticed a
changeset that removed its export and added it to _ksyms.c on a few more
architectures.  The justification was that "other arches do it."

I think this is wrong, since no architecture currently defines
__HAVE_ARCH_STRPBRK, there's no reason for any of them to be exporting it
themselves.  Therefore, consolidate the export to lib/string.c.
Signed-off-by: NKyle McMartin <kyle@parisc-linux.org>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

for_each_cpu() actually iterates across all possible CPUs.  We've had mistakes
in the past where people were using for_each_cpu() where they should have been
iterating across only online or present CPUs.  This is inefficient and
possibly buggy.

We're renaming for_each_cpu() to for_each_possible_cpu() to avoid this in the
future.

This patch replaces for_each_cpu with for_each_possible_cpu.
for sparc64.
Signed-off-by: NKAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Acked-by: N"David S. Miller" <davem@davemloft.net>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Otherwise the build breaks with EXPERIMENTAL disabled
because SPARSEMEM will not get selected properly.  See
mm/Kconfig for how that works.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

1) Take doc-book function comment from i386 implementation.
2) cacheline align call_lock, taken from powerpc
3) Need memory barrier after setting call_data
4) Remove timeout
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This makes debugging things a little bit easier.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

GDB uses a PTRACE_PEEKUSR call with offset 0 to see
if a thread is alive, so provide a success return for
this particular special case.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Signed-off-by: NDavid S. Miller <davem@davemloft.net>

We are about to fill in all HPAGE_SIZE's worth
of PAGE_SIZE ptes, so we have to give the first
pte in that set else we scribble over random memory
when we fill in the ptes.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Signed-off-by: NDavid S. Miller <davem@davemloft.net>

switch_mm() changes the mm state and does a tsb_context_switch()
first, then we do the cpu register state switch which changes
current_thread_info() and current().

So it's safer to check the PGD physical address stored in the
trap block (which will be updated by the tsb_context_switch() in
switch_mm()) than current->active_mm.

Technically we should never run here in between those two
updates, because interrupts are disabled during the entire
context switch operation.  But some day we might like to leave
interrupts enabled during the context switch and this change
allows that to happen without any surprises.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Signed-off-by: NMatt Mackall <mpm@selenic.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

The kernel's implementation of notifier chains is unsafe.  There is no
protection against entries being added to or removed from a chain while the
chain is in use.  The issues were discussed in this thread:

    http://marc.theaimsgroup.com/?l=linux-kernel&m=113018709002036&w=2

We noticed that notifier chains in the kernel fall into two basic usage
classes:

	"Blocking" chains are always called from a process context
	and the callout routines are allowed to sleep;

	"Atomic" chains can be called from an atomic context and
	the callout routines are not allowed to sleep.

We decided to codify this distinction and make it part of the API.  Therefore
this set of patches introduces three new, parallel APIs: one for blocking
notifiers, one for atomic notifiers, and one for "raw" notifiers (which is
really just the old API under a new name).  New kinds of data structures are
used for the heads of the chains, and new routines are defined for
registration, unregistration, and calling a chain.  The three APIs are
explained in include/linux/notifier.h and their implementation is in
kernel/sys.c.

With atomic and blocking chains, the implementation guarantees that the chain
links will not be corrupted and that chain callers will not get messed up by
entries being added or removed.  For raw chains the implementation provides no
guarantees at all; users of this API must provide their own protections.  (The
idea was that situations may come up where the assumptions of the atomic and
blocking APIs are not appropriate, so it should be possible for users to
handle these things in their own way.)

There are some limitations, which should not be too hard to live with.  For
atomic/blocking chains, registration and unregistration must always be done in
a process context since the chain is protected by a mutex/rwsem.  Also, a
callout routine for a non-raw chain must not try to register or unregister
entries on its own chain.  (This did happen in a couple of places and the code
had to be changed to avoid it.)

Since atomic chains may be called from within an NMI handler, they cannot use
spinlocks for synchronization.  Instead we use RCU.  The overhead falls almost
entirely in the unregister routine, which is okay since unregistration is much
less frequent that calling a chain.

Here is the list of chains that we adjusted and their classifications.  None
of them use the raw API, so for the moment it is only a placeholder.

  ATOMIC CHAINS
  -------------
arch/i386/kernel/traps.c:		i386die_chain
arch/ia64/kernel/traps.c:		ia64die_chain
arch/powerpc/kernel/traps.c:		powerpc_die_chain
arch/sparc64/kernel/traps.c:		sparc64die_chain
arch/x86_64/kernel/traps.c:		die_chain
drivers/char/ipmi/ipmi_si_intf.c:	xaction_notifier_list
kernel/panic.c:				panic_notifier_list
kernel/profile.c:			task_free_notifier
net/bluetooth/hci_core.c:		hci_notifier
net/ipv4/netfilter/ip_conntrack_core.c:	ip_conntrack_chain
net/ipv4/netfilter/ip_conntrack_core.c:	ip_conntrack_expect_chain
net/ipv6/addrconf.c:			inet6addr_chain
net/netfilter/nf_conntrack_core.c:	nf_conntrack_chain
net/netfilter/nf_conntrack_core.c:	nf_conntrack_expect_chain
net/netlink/af_netlink.c:		netlink_chain

  BLOCKING CHAINS
  ---------------
arch/powerpc/platforms/pseries/reconfig.c:	pSeries_reconfig_chain
arch/s390/kernel/process.c:		idle_chain
arch/x86_64/kernel/process.c		idle_notifier
drivers/base/memory.c:			memory_chain
drivers/cpufreq/cpufreq.c		cpufreq_policy_notifier_list
drivers/cpufreq/cpufreq.c		cpufreq_transition_notifier_list
drivers/macintosh/adb.c:		adb_client_list
drivers/macintosh/via-pmu.c		sleep_notifier_list
drivers/macintosh/via-pmu68k.c		sleep_notifier_list
drivers/macintosh/windfarm_core.c	wf_client_list
drivers/usb/core/notify.c		usb_notifier_list
drivers/video/fbmem.c			fb_notifier_list
kernel/cpu.c				cpu_chain
kernel/module.c				module_notify_list
kernel/profile.c			munmap_notifier
kernel/profile.c			task_exit_notifier
kernel/sys.c				reboot_notifier_list
net/core/dev.c				netdev_chain
net/decnet/dn_dev.c:			dnaddr_chain
net/ipv4/devinet.c:			inetaddr_chain

It's possible that some of these classifications are wrong.  If they are,
please let us know or submit a patch to fix them.  Note that any chain that
gets called very frequently should be atomic, because the rwsem read-locking
used for blocking chains is very likely to incur cache misses on SMP systems.
(However, if the chain's callout routines may sleep then the chain cannot be
atomic.)

The patch set was written by Alan Stern and Chandra Seetharaman, incorporating
material written by Keith Owens and suggestions from Paul McKenney and Andrew
Morton.

[jes@sgi.com: restructure the notifier chain initialization macros]
Signed-off-by: NAlan Stern <stern@rowland.harvard.edu>
Signed-off-by: NChandra Seetharaman <sekharan@us.ibm.com>
Signed-off-by: NJes Sorensen <jes@sgi.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

The worst part about this bug is what it would cause
a hugepage TSB to be allocated for every address space
since "0 >= 0".
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Kbuild now points these out.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Signed-off-by: NDavid S. Miller <davem@davemloft.net>