This patch allows each architecture to add its specific assembly optimized
arch_mcs_spin_lock_contended and arch_mcs_spinlock_uncontended for
MCS lock and unlock functions.
Signed-off-by: NTim Chen <tim.c.chen@linux.intel.com>
Cc: Scott J Norton <scott.norton@hp.com>
Cc: Raghavendra K T <raghavendra.kt@linux.vnet.ibm.com>
Cc: AswinChandramouleeswaran <aswin@hp.com>
Cc: George Spelvin <linux@horizon.com>
Cc: Rik vanRiel <riel@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: MichelLespinasse <walken@google.com>
Cc: Peter Hurley <peter@hurleysoftware.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Alex Shi <alex.shi@linaro.org>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Tim Chen <tim.c.chen@linux.intel.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: "Figo.zhang" <figo1802@gmail.com>
Cc: "Paul E.McKenney" <paulmck@linux.vnet.ibm.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Davidlohr Bueso <davidlohr.bueso@hp.com>
Cc: Waiman Long <waiman.long@hp.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Matthew R Wilcox <matthew.r.wilcox@intel.com>
Signed-off-by: NPeter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1390347382.3138.67.camel@schen9-DESKSigned-off-by: NIngo Molnar <mingo@kernel.org>

We perform a clean up of the Kbuid files in each architecture.
We order the files in each Kbuild in alphabetical order
by running the below script.

for i in arch/*/include/asm/Kbuild
do
        cat $i | gawk '/^generic-y/ {
                i = 3;
                do {
                        for (; i <= NF; i++) {
                                if ($i == "\\") {
                                        getline;
                                        i = 1;
                                        continue;
                                }
                                if ($i != "")
                                        hdr[$i] = $i;
                        }
                        break;
                } while (1);
                next;
        }
        // {
                print $0;
        }
        END {
                n = asort(hdr);
                for (i = 1; i <= n; i++)
                        print "generic-y += " hdr[i];
        }' > ${i}.sorted;
        mv ${i}.sorted $i;
done
Signed-off-by: NTim Chen <tim.c.chen@linux.intel.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Matthew R Wilcox <matthew.r.wilcox@intel.com>
Cc: AswinChandramouleeswaran <aswin@hp.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: "Paul E.McKenney" <paulmck@linux.vnet.ibm.com>
Cc: Scott J Norton <scott.norton@hp.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: "Figo.zhang" <figo1802@gmail.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Waiman Long <waiman.long@hp.com>
Cc: Peter Hurley <peter@hurleysoftware.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Tim Chen <tim.c.chen@linux.intel.com>
Cc: Alex Shi <alex.shi@linaro.org>
Cc: Raghavendra K T <raghavendra.kt@linux.vnet.ibm.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: George Spelvin <linux@horizon.com>
Cc: MichelLespinasse <walken@google.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Davidlohr Bueso <davidlohr.bueso@hp.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: NPeter Zijlstra <peterz@infradead.org>
[ Fixed build bug. ]
Signed-off-by: NIngo Molnar <mingo@kernel.org>

With commit d8d14bd0 ("fs/compat: fix lookup_dcookie() parameter
handling") I changed the type of the len parameter of the
lookup_dcookie() syscall.

However I missed that there was still a stale declaration in
arch/tile/..  which now causes a compile error on tile:

  In file included from fs/dcookies.c:28:0:
  include/linux/compat.h:425:17: error: conflicting types for 'compat_sys_lookup_dcookie'
  fs/dcookies.c:207:1: error: conflicting types for 'compat_sys_lookup_dcookie'

Simply remove the declaration in the tile architecture, which is only a
leftover from before the different compat lookup_dcookie() versions have
been merged.  The correct declaration is now in include/linux/compat.h

The build error was reported by Fenguang's build bot.
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Acked-by: NChris Metcalf <cmetcalf@tilera.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Signed-off-by: NMark Salter <msalter@redhat.com>
Acked-by: NChris Metcalf <cmetcalf@tilera.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

We're going to be adding a few new barrier primitives, and in order to
avoid endless duplication make more agressive use of
asm-generic/barrier.h.

Change the asm-generic/barrier.h such that it allows partial barrier
definitions and fills out the rest with defaults.

There are a few architectures (m32r, m68k) that could probably
do away with their barrier.h file entirely but are kept for now due to
their unconventional nop() implementation.
Suggested-by: NGeert Uytterhoeven <geert@linux-m68k.org>
Reviewed-by: N"Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Reviewed-by: NMathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
Signed-off-by: NPeter Zijlstra <peterz@infradead.org>
Cc: Michael Ellerman <michael@ellerman.id.au>
Cc: Michael Neuling <mikey@neuling.org>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Victor Kaplansky <VICTORK@il.ibm.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Link: http://lkml.kernel.org/r/20131213150640.846368594@infradead.orgSigned-off-by: NIngo Molnar <mingo@kernel.org>

Reported-by: NStephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

No point in having this bit defined by architecture.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Acked-by: NPeter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20130917183629.090698799@linutronix.de

There is no reason for per arch hardirq bits. Make them all generic
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Acked-by: NPeter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20130917183628.534494408@linutronix.de

It turns out the kernel relies on barrier() to force a reload of the
percpu offset value.  Since we can't easily modify the definition of
barrier() to include "tp" as an output register, we instead provide a
definition of __my_cpu_offset as extended assembly that includes a fake
stack read to hazard against barrier(), forcing gcc to know that it
must reread "tp" and recompute anything based on "tp" after a barrier.

This fixes observed hangs in the slub allocator when we are looping
on a percpu cmpxchg_double.

A similar fix for ARMv7 was made in June in change 509eb76e.

Cc: stable@vger.kernel.org
Signed-off-by: NChris Metcalf <cmetcalf@tilera.com>

atomic* value is signed value, and atomic* functions need also process
signed value (parameter value, and return value), so use 'long long'
instead of 'u64'.

After replacement, it will also fix a bug for atomic64_add_negative():
"u64 is never less than 0".

The modifications are:

  in vim, use "1,% s/\<u64\>/long long/g" command.
  remove redundant '__aligned(8)'.
  be sure of 80 (and macro '\') columns limitation after replacement.
Signed-off-by: NChen Gang <gang.chen@asianux.com>
Signed-off-by: Chris Metcalf <cmetcalf@tilera.com> [re-instated const cast]

In order to prepare to per-arch implementations of preempt_count move
the required bits into an asm-generic header and use this for all
archs.
Signed-off-by: NPeter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/n/tip-h5j0c1r3e3fk015m30h8f1zx@git.kernel.orgSigned-off-by: NIngo Molnar <mingo@kernel.org>

The hardware architecture descriptor headers have been updated, in
particular to reflect some larger MMIO fields on the mPIPE shims for
controlling the network hardware, from the recent Gx72 release.
Signed-off-by: NChris Metcalf <cmetcalf@tilera.com>

Fix some whitespace style issues in some auto-generated files.
Signed-off-by: NChris Metcalf <cmetcalf@tilera.com>

A config option to allow a variant vmap() using huge pages that was never
upstreamed had some bits of code related to it scattered around the tile
architecture; the config option was removed downstream and this commit
cleans up the scattered evidence of it from the upstream as well.
Signed-off-by: NChris Metcalf <cmetcalf@tilera.com>

The macrology in cmpxchg.h was designed to allow arbitrary pointer
and integer values to be passed through the routines.  To support
cmpxchg() on 64-bit values on the 32-bit tilepro architecture, we
used the idiom "(typeof(val))(typeof(val-val))".  This way, in the
"size 8" branch of the switch, when the underlying cmpxchg routine
returns a 64-bit quantity, we cast it first to a typeof(val-val)
quantity (i.e. size_t if "val" is a pointer) with no warnings about
casting between pointers and integers of different sizes, then cast
onwards to typeof(val), again with no warnings.  If val is not a
pointer type, the additional cast is a no-op.  We can't replace the
typeof(val-val) cast with (for example) unsigned long, since then if
"val" is really a 64-bit type, we cast away the high bits.

HOWEVER, this fails with current gcc (through 4.7 at least) if "val"
is a pointer to an incomplete type.  Unfortunately gcc isn't smart
enough to realize that "val - val" will always be a size_t type
even if it's an incomplete type pointer.

Accordingly, I've reworked the way we handle the casting.  We have
given up the ability to use cmpxchg() on 64-bit values on tilepro,
which is OK in the kernel since we should use cmpxchg64() explicitly
on such values anyway.  As a result, I can just use simple "unsigned
long" casts internally.

As I reworked it, I realized it would be cleaner to move the
architecture-specific conditionals for cmpxchg and xchg out of the
atomic.h headers and into cmpxchg, and then use the cmpxchg() and
xchg() primitives directly in atomic.h and elsewhere.  This allowed
the cmpxchg.h header to stand on its own without relying on the
implicit include of it that is performed by <asm/atomic.h>.
It also allowed collapsing the atomic_xchg/atomic_cmpxchg routines
from atomic_{32,64}.h into atomic.h.

I improved the tests that guard the allowed size of the arguments
to the routines to use a __compiletime_error() test.  (By avoiding
the use of BUILD_BUG, I could include cmpxchg.h into bitops.h as
well and use the macros there, which is otherwise impossible due
to include order dependency issues.)

The tilepro _atomic_xxx internal methods were previously set up to
take atomic_t and atomic64_t arguments, which isn't as convenient
with the new model, so I modified them to take int or u64 arguments,
which is consistent with how they used the arguments internally
anyway, so provided some nice simplification there too.
Signed-off-by: NChris Metcalf <cmetcalf@tilera.com>

This change sets the PCI devices' initial DMA capabilities
conservatively and promotes them at the request of the driver,
as opposed to assuming advanced DMA capabilities. The old design
runs the risk of breaking drivers that assume default capabilities.
Signed-off-by: NChris Metcalf <cmetcalf@tilera.com>

This was really only useful for TILE64 when we mapped the
kernel data with small pages. Now we use a huge page and we
really don't want to map different parts of the kernel
data in different ways.

We retain the __write_once name in case we want to bring
it back to life at some point in the future.

Note that this change uncovered a latent bug where the
"smp_topology" variable happened to always be aligned mod 8
so we could store two "int" values at once, but when we
eliminated __write_once it ended up only aligned mod 4.
Fix with an explicit annotation.
Signed-off-by: NChris Metcalf <cmetcalf@tilera.com>

This chip is no longer being actively developed for (it was superceded
by the TILEPro64 in 2008), and in any case the existing compiler and
toolchain in the community do not support it.  It's unlikely that the
kernel works with TILE64 at this point as the configuration has not been
tested in years.  The support is also awkward as it requires maintaining
a significant number of ifdefs.  So, just remove it altogether.
Signed-off-by: NChris Metcalf <cmetcalf@tilera.com>

The definisions of __ffs(), __fls(), and ffs() for tile are almost same
as asm-generic/bitops-*.h.  The only difference is that it is defined
as __always_inline or inline.  So this switches to use those headers.
Signed-off-by: NAkinobu Mita <akinobu.mita@gmail.com>
Signed-off-by: Chris Metcalf <cmetcalf@tilera.com> [moved #includes to end]

Signed-off-by: NChris Metcalf <cmetcalf@tilera.com>

Signed-off-by: NChris Metcalf <cmetcalf@tilera.com>

Explain the rationale of not overlapping the 64-bit DMA window
with the PA range.
Signed-off-by: NChris Metcalf <cmetcalf@tilera.com>

We use virt_to_pte(NULL, va) a lot, which isn't very obvious.
I added virt_to_kpte(va) as a more obvious wrapper function,
that also validates the va as being a kernel adddress.

And, I fixed the semantics of virt_to_pte() so that we handle
the pud and pmd the same way, and we now document the fact that
we handle the final pte level differently.
Signed-off-by: NChris Metcalf <cmetcalf@tilera.com>

Newer hypervisors have an API for reporting per-cpu statistics
information.  This change allows seeing that information via
/sys/devices/system/cpu/cpuN/hv_stats file for each core.
Signed-off-by: NChris Metcalf <cmetcalf@tilera.com>

Enter kernel debugger at boot with:
  --hvd UART_1=1 --hvx kgdbwait --hvx kgdboc=ttyS1,115200
or at runtime with:
  echo ttyS1,115200 > /sys/module/kgdboc/parameters/kgdboc
  echo g > /proc/sysrq-trigger
Signed-off-by: NChris Metcalf <cmetcalf@tilera.com>

The TILE-Gx chip includes an on-chip UART.  This change adds support
for using the UART from within the kernel.  The UART shim has more
functionality than is exposed here, but to keep the kernel code and
binary simpler, this is a subset of the full API designed to enable
a standard Linux tty serial driver only.
Signed-off-by: NChris Metcalf <cmetcalf@tilera.com>

The existing code relied on the hardware definition (<arch/chip.h>)
to specify how much VA and PA space was available.  It's convenient
to allow customizing this for some configurations, so provide symbols
MAX_PA_WIDTH and MAX_VA_WIDTH in <asm/page.h> that can be modified
if desired.

Additionally, move away from the MEM_XX_INTRPT nomenclature to
define the start of various regions within the VA space.  In fact
the cleaner symbol is, for example, MEM_SV_START, to indicate the
start of the area used for supervisor code; the actual address of the
interrupt vectors is not as important, and can be changed if desired.
As part of this change, convert from "intrpt1" nomenclature (which
built in the old privilege-level 1 model) to a simple "intrpt".

Also strip out some tilepro-specific code supporting modifying the
PL the kernel could run at, since we don't actually support using
different PLs in tilepro, only tilegx.
Signed-off-by: NChris Metcalf <cmetcalf@tilera.com>

Technically, user privilege is anything less than kernel
privilege.  We modify the existing user_mode() macro to have
this semantic (and use it in a couple of places it wasn't being
used before), and add an IS_KERNEL_EX1() macro to the assembly
code as well.
Signed-off-by: NChris Metcalf <cmetcalf@tilera.com>

This tile-specific API had a minor bug, in that if a super huge (>4GB)
page mapped a particular address range, we wouldn't handle it correctly.
As part of fixing that bug, I also cleaned up some of the pud and pmd
accessors to make them more consistent.
Signed-off-by: NChris Metcalf <cmetcalf@tilera.com>

Previously, we used a special-purpose register (SPR_SYSTEM_SAVE_K_0)
to hold the CPU number and the top of the current kernel stack
by using the low bits to hold the CPU number, and using the high
bits to hold the address of the page just above where we'd want
the kernel stack to be.  That way we could initialize a new SP
when first entering the kernel by just masking the SPR value and
subtracting a couple of words.

However, it's actually more useful to be able to place an arbitrary
kernel-top value in the SPR.  This allows us to create a new stack
context (e.g. for virtualization) with an arbitrary top-of-stack VA.
To make this work, we now store the CPU number in the high bits,
above the highest legal VA bit (42 bits in the current tilegx
microarchitecture).  The full 42 bits are thus available to store the
top of stack value.  Getting the current cpu (a relatively common
operation) is still fast; it's now a shift rather than a mask.

We make this change only for tilegx, since tilepro has too few SPR
bits to do this, and we don't need this support on tilepro anyway.
Signed-off-by: NChris Metcalf <cmetcalf@tilera.com>

Normally the build doesn't include these warnings, but at one
point I built with -Wsign-compare, and noticed a few things that
are technically bugs.  This change fixes those things.
Signed-off-by: NChris Metcalf <cmetcalf@tilera.com>

Nothing in the codebase was using them, and as written they took
"unsigned long" as the physical address rather than "phys_addr_t",
which is wrong on tilepro anyway.  Rather than fixing stale APIs,
just remove them; if there's ever demand for them on this platform,
we can put them back.
Signed-off-by: NChris Metcalf <cmetcalf@tilera.com>

With this change, tile Linux now supports address-space layout
randomization for shared objects, stack, heap and vdso.
Acked-by: NJiri Kosina <jkosina@suse.cz>
Signed-off-by: NTony Lu <zlu@tilera.com>
Signed-off-by: NChris Metcalf <cmetcalf@tilera.com>

This may fix a reported bug where an R_TILEGX_64 in a module was not
pointing to an aligned address.
Reported-by: NSimon Marchi <simon.marchi@polymtl.ca>
Signed-off-by: NChris Metcalf <cmetcalf@tilera.com>

This change includes support for Kprobes, Jprobes and Return Probes.
Reviewed-by: NMasami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Signed-off-by: NTony Lu <zlu@tilera.com>
Signed-off-by: NChris Metcalf <cmetcalf@tilera.com>

This commit adds support for static ftrace, graph function support,
and dynamic tracer support.
Signed-off-by: NTony Lu <zlu@tilera.com>
Signed-off-by: NChris Metcalf <cmetcalf@tilera.com>

This change creates the framework for vDSO calls, makes the existing
rt_sigreturn() mechanism use it, and adds a fast gettimeofday().
Now that we need to expose the vDSO address to userspace, we add
AT_SYSINFO_EHDR to the set of aux entries provided to userspace.
(You can disable any extra vDSO support by booting with vdso=0,
but the rt_sigreturn vDSO page will still be provided.)

Note that glibc has supported the tile vDSO since release 2.17.
Signed-off-by: NChris Metcalf <cmetcalf@tilera.com>

First, fix a bug in asm/unaligned.h; we need to just use the asm-generic
unaligned.h so we properly choose endian-correct flavors.

Second, keep the hv/hypervisor.h ABI fully "native" in the sense that
we don't have __BIG_ENDIAN__ ifdefs there.  Instead, we use macros in
the head_NN.S assembly code to properly extract two 32-bit structure
members from a 64-bit register holding the structure.
Signed-off-by: NChris Metcalf <cmetcalf@tilera.com>

This change adds support for CONFIG_PREEMPT (full kernel preemption).
In addition to the core support, this change includes a number
of places where we fix up uses of smp_processor_id() and per-cpu
variables.  I also eliminate the PAGE_HOME_HERE and PAGE_HOME_UNKNOWN
values for page homing, as it turns out they weren't being used.
Signed-off-by: NChris Metcalf <cmetcalf@tilera.com>

This change adds support for avoiding recursive backtracer crashes;
we haven't seen this in practice other than when things are seriously
corrupt, but it may help avoid losing the root cause of a crash.

Also, don't abort kernel backtracers for invalid userspace PC's.
If we do, we lose the ability to backtrace through a userspace
call to a bad address above PAGE_OFFSET, even though that it can
be perfectly reasonable to continue the backtrace in such a case.
Signed-off-by: NChris Metcalf <cmetcalf@tilera.com>