Commit Graph

98 Commits

Author SHA1 Message Date
Chris Metcalf
81711cee93 arch/tile: handle rt_sigreturn() more cleanly
The current tile rt_sigreturn() syscall pattern uses the common idiom
of loading up pt_regs with all the saved registers from the time of
the signal, then anticipating the fact that we will clobber the ABI
"return value" register (r0) as we return from the syscall by setting
the rt_sigreturn return value to whatever random value was in the pt_regs
for r0.

However, this breaks in our 64-bit kernel when running "compat" tasks,
since we always sign-extend the "return value" register to properly
handle returned pointers that are in the upper 2GB of the 32-bit compat
address space.  Doing this to the sigreturn path then causes occasional
random corruption of the 64-bit r0 register.

Instead, we stop doing the crazy "load the return-value register"
hack in sigreturn.  We already have some sigreturn-specific assembly
code that we use to pass the pt_regs pointer to C code.  We extend that
code to also set the link register to point to a spot a few instructions
after the usual syscall return address so we don't clobber the saved r0.
Now it no longer matters what the rt_sigreturn syscall returns, and the
pt_regs structure can be cleanly and completely reloaded.

Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
2010-12-17 16:59:29 -05:00
Chris Metcalf
bc4cf2bb27 arch/tile: handle CLONE_SETTLS in copy_thread(), not user space
Previously we were just setting up the "tp" register in the
new task as started by clone() in libc.  However, this is not
quite right, since in principle a signal might be delivered to
the new task before it had its TLS set up.  (Of course, this race
window still exists for resetting the libc getpid() cached value
in the new task, in principle.  But in any case, we are now doing
this exactly the way all other architectures do it.)

This change is important for 2.6.37 since the tile glibc we will
be submitting upstream will not set TLS in user space any more,
so it will only work on a kernel that has this fix.  It should
also be taken for 2.6.36.x in the stable tree if possible.

Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
Cc: stable <stable@kernel.org>
2010-12-17 16:56:50 -05:00
Linus Torvalds
c12ae95ccc Merge git://git.kernel.org/pub/scm/linux/kernel/git/cmetcalf/linux-tile
* git://git.kernel.org/pub/scm/linux/kernel/git/cmetcalf/linux-tile:
  arch/tile: fix memchr() not to dereference memory for zero length
  arch/tile: make glibc's sysconf(_SC_NPROCESSORS_CONF) work correctly
  arch/tile: fix rwlock so would-be write lockers don't block new readers
2010-11-25 07:42:32 +09:00
Linus Torvalds
47143b094d Merge branch 'drivers' of git://git.kernel.org/pub/scm/linux/kernel/git/cmetcalf/linux-tile
* 'drivers' of git://git.kernel.org/pub/scm/linux/kernel/git/cmetcalf/linux-tile:
  pci root complex: support for tile architecture
  drivers/net/tile/: on-chip network drivers for the tile architecture
  MAINTAINERS: add drivers/char/hvc_tile.c as maintained by tile
2010-11-25 07:42:03 +09:00
Chris Metcalf
3edabee2ed arch/tile: fix memchr() not to dereference memory for zero length
This change fixes a bug that memchr() will read the first word
of the source even if the length is zero.  Ironically, the code
was originally written with a test to avoid exactly this problem,
but to make the code conform to Linux coding standards with all
declarations preceding all statements, the first load from memory
was moved up above that test as the initial value for a variable.

The change just moves all the variable declarations to the top
of the file, with no initializers, so that the test can also be
at the top of the file.

Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
2010-11-24 13:57:42 -05:00
Chris Metcalf
4d658d13c9 arch/tile: make glibc's sysconf(_SC_NPROCESSORS_CONF) work correctly
glibc assumes that it can count /sys/devices/system/cpu/cpu* to get
the number of configured cpus.  For this to be valid on tile, we need
to generate a "cpu" entry for all cpus, including the ones that are
not currently allocated for Linux's use.

Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
2010-11-24 13:42:15 -05:00
Chris Metcalf
b03a6c4c7d Merge branch 'master' into for-linus 2010-11-24 13:30:28 -05:00
Chris Metcalf
f02cbbe657 pci root complex: support for tile architecture
This change enables PCI root complex support for TILEPro.  Unlike
TILE-Gx, TILEPro has no support for memory-mapped I/O, so the PCI
support consists of hypervisor upcalls for PIO, DMA, etc.  However,
the performance is fine for the devices we have tested with so far
(1Gb Ethernet, SATA, etc.).

The <asm/io.h> header was tweaked to be a little bit more aggressive
about disabling attempts to map/unmap IO port space.  The hacky
<asm/pci-bridge.h> header was rolled into the <asm/pci.h> header
and the result was simplified.  Both of the latter two headers were
preliminary versions not meant for release before now - oh well.

There is one quirk for our TILEmpower platform, which accidentally
negotiates up to 5GT and needs to be kicked down to 2.5GT.

Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
2010-11-24 13:13:49 -05:00
Chris Metcalf
e5a0693973 drivers/net/tile/: on-chip network drivers for the tile architecture
This change adds the first network driver for the tile architecture,
supporting the on-chip XGBE and GBE shims.

The infrastructure is present for the TILE-Gx networking drivers (another
three source files in the new directory) but for now the the actual
tilegx sources are waiting on releasing hardware to initial customers.

Note that arch/tile/include/hv/* are "upstream" headers from the
Tilera hypervisor and will probably benefit less from LKML review.

Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
2010-11-24 13:11:18 -05:00
Arnd Bergmann
451a3c24b0 BKL: remove extraneous #include <smp_lock.h>
The big kernel lock has been removed from all these files at some point,
leaving only the #include.

Remove this too as a cleanup.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-11-17 08:59:32 -08:00
Chris Metcalf
24f3f6b5ef arch/tile: fix rwlock so would-be write lockers don't block new readers
This avoids a deadlock in the IGMP code where one core gets a read
lock, another core starts trying to get a write lock (thus blocking
new readers), and then the first core tries to recursively re-acquire
the read lock.

We still try to preserve some degree of balance by giving priority
to additional write lockers that come along while the lock is held
for write, so they can all complete quickly and return the lock to
the readers.

Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
2010-11-15 09:18:49 -05:00
Chris Metcalf
d02db4f8d7 arch/tile: mark "hardwall" device as non-seekable
Arnd's recent patch series tagged this device with noop_llseek,
conservatively.  In fact, it should be no_llseek, which we arrange
for by opening the device with nonseekable_open().

Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
2010-11-01 15:31:42 -04:00
Chris Metcalf
2c7387ef99 asm-generic/stat.h: support 64-bit file time_t for stat()
The existing asm-generic/stat.h specifies st_mtime, etc., as a 32-value,
and works well for 32-bit architectures (currently microblaze, score,
and 32-bit tile).  However, for 64-bit architectures it isn't sufficient
to return 32 bits of time_t; this isn't good insurance against the 2037
rollover.  (It also makes glibc support less convenient, since we can't
use glibc's handy STAT_IS_KERNEL_STAT mode.)

This change extends the two "timespec" fields for each of the three atime,
mtime, and ctime fields from "int" to "long".  As a result, on 32-bit
platforms nothing changes, and 64-bit platforms will now work as expected.

The only wrinkle is 32-bit userspace under 64-bit kernels taking advantage
of COMPAT mode.  For these, we leave the "struct stat64" definitions with
the "int" versions of the time_t and nsec fields, so that architectures
can implement compat_sys_stat64() and friends with sys_stat64(), etc.,
and get the expected 32-bit structure layout.  This requires a
field-by-field copy in the kernel, implemented by the code guarded
under __ARCH_WANT_STAT64.

This does mean that the shape of the "struct stat" and "struct stat64"
structures is different on a 64-bit kernel, but only one of the two
structures should ever be used by any given process: "struct stat"
is meant for 64-bit userspace only, and "struct stat64" for 32-bit
userspace only.  (On a 32-bit kernel the two structures continue to have
the same shape, since "long" is 32 bits.)

The alternative is keeping the two structures the same shape on 64-bit
kernels, which means a 64-bit time_t in "struct stat64" for 32-bit
processes.  This is a little unnatural since 32-bit userspace can't
do anything with 64 bits of time_t information, since time_t is just
"long", not "int64_t"; and in any case 32-bit userspace might expect
to be running under a 32-bit kernel, which can't provide the high 32
bits anyway.  In the case of a 32-bit kernel we'd then be extending the
kernel's 32-bit time_t to 64 bits, then truncating it back to 32 bits
again in userspace, for no particular reason.  And, as mentioned above,
if we have 64-bit time_t for 32-bit processes we can't easily use glibc's
STAT_IS_KERNEL_STAT, since glibc's stat structure requires an embedded
"struct timespec", which is a pair of "long" (32-bit) values in a 32-bit
userspace.  "Inventive" solutions are possible, but are pretty hacky.

Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
2010-11-01 15:31:29 -04:00
Chris Metcalf
1deb9c5dfb arch/tile: don't allow user code to set the PL via ptrace or signal return
The kernel was allowing any component of the pt_regs to be updated either
by signal handlers writing to the stack, or by processes writing via
PTRACE_POKEUSR or PTRACE_SETREGS, which meant they could set their PL
up from 0 to 1 and get access to kernel code and data (or, in practice,
cause a kernel panic).  We now always reset the ex1 field, allowing the
user to set their ICS bit only.

Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
2010-11-01 15:31:17 -04:00
Chris Metcalf
34a89d26bd arch/tile: correct double syscall restart for nested signals
This change is modelled on similar fixes for other architectures.
The pt_regs "faultnum" member is set to the trap (fault) number that
caused us to enter the kernel, and is INT_SWINT_1 for the syscall software
interrupt.  We already supported a pseudo value, INT_SWINT_1_SIGRETURN,
that we used for the rt_sigreturn syscall; it avoided the case where
one signal was handled, then we "tail-called" to another handler.

This change avoids the similar case where we start to call one handler,
then are preempted into another handler when we start trying to run
the first handler.  We clear ->faultnum after calling handle_signal(),
and to be paranoid also in the case where there was no signal to deliver.

Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
2010-11-01 15:31:04 -04:00
Chris Metcalf
d59e609d65 arch/tile: avoid __must_check warning on one strict_strtol check
For the "initfree" boot argument it's not that big a deal, but
to avoid warnings in the code, we check for a valid value before
allowing the specified argument to override the kernel default.

Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
2010-11-01 15:30:53 -04:00
Chris Metcalf
5d966115de arch/tile: bomb raw_local_irq_ to arch_local_irq_
This completes the tile migration to the new naming scheme for
the architecture-specific irq management code.

Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
2010-11-01 15:30:42 -04:00
Chris Metcalf
38a6f42669 arch/tile: complete migration to new kmap_atomic scheme
This change makes KM_TYPE_NR independent of the actual deprecated
list of km_type values, which are no longer used in tile code anywhere.
For now we leave it set to 8, allowing that many nested mappings,
and thus reserving 32MB of address space.

A few remaining places using KM_* values were cleaned up as well.

Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
2010-11-01 15:30:36 -04:00
Linus Torvalds
51399a3919 Merge branch 'kconfig' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild-2.6
* 'kconfig' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild-2.6: (38 commits)
  kbuild: convert `arch/tile' to the kconfig mainmenu upgrade
  README: cite nconfig
  Revert "kconfig: Temporarily disable dependency warnings"
  kconfig: Use PATH_MAX instead of 128 for path buffer sizes.
  kconfig: Fix realloc usage()
  kconfig: Propagate const
  kconfig: Don't go out from read config loop when you read new symbol
  kconfig: fix menuconfig on debian lenny
  kbuild: migrate all arch to the kconfig mainmenu upgrade
  kconfig: expand file names
  kconfig: use the file's name of sourced file
  kconfig: constify file name
  kconfig: don't emit warning upon rootmenu's prompt redefinition
  kconfig: replace KERNELVERSION usage by the mainmenu's prompt
  kconfig: delay gconf window initialization
  kconfig: expand by default the rootmenu's prompt
  kconfig: add a symbol string expansion helper
  kconfig: regen parser
  kconfig: implement the `mainmenu' directive
  kconfig: allow PACKAGE to be defined on the compiler's command-line
  ...

Fix up trivial conflict in arch/mn10300/Kconfig
2010-10-28 16:16:39 -07:00
Arnaud Lacombe
df4d303647 kbuild: convert `arch/tile' to the kconfig mainmenu upgrade
Signed-off-by: Arnaud Lacombe <lacombar@gmail.com>
Signed-off-by: Michal Marek <mmarek@suse.cz>
2010-10-28 22:41:14 +02:00
Zimny Lech
61d8e11e51 Remove duplicate includes from many files
Signed-off-by: Zimny Lech <napohybelskurwysynom2010@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-10-27 18:03:18 -07:00
Namhyung Kim
8c0acac367 ptrace: cleanup arch_ptrace() on tile
Remove checking @addr less than 0 because @addr is now unsigned.

Signed-off-by: Namhyung Kim <namhyung@gmail.com>
Acked-by: Chris Metcalf <cmetcalf@tilera.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-10-27 18:03:12 -07:00
Namhyung Kim
9b05a69e05 ptrace: change signature of arch_ptrace()
Fix up the arguments to arch_ptrace() to take account of the fact that
@addr and @data are now unsigned long rather than long as of a preceding
patch in this series.

Signed-off-by: Namhyung Kim <namhyung@gmail.com>
Cc: <linux-arch@vger.kernel.org>
Acked-by: Roland McGrath <roland@redhat.com>
Acked-by: David Howells <dhowells@redhat.com>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-10-27 18:03:10 -07:00
FUJITA Tomonori
d31eb5194b tile: enable ARCH_DMA_ADDR_T_64BIT
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Acked-by: Chris Metcalf <cmetcalf@tilera.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-10-27 18:03:05 -07:00
Peter Zijlstra
20273941f2 mm: fix race in kunmap_atomic()
Christoph reported a nice splat which illustrated a race in the new stack
based kmap_atomic implementation.

The problem is that we pop our stack slot before we're completely done
resetting its state -- in particular clearing the PTE (sometimes that's
CONFIG_DEBUG_HIGHMEM).  If an interrupt happens before we actually clear
the PTE used for the last slot, that interrupt can reuse the slot in a
dirty state, which triggers a BUG in kmap_atomic().

Fix this by introducing kmap_atomic_idx() which reports the current slot
index without actually releasing it and use that to find the PTE and delay
the _pop() until after we're completely done.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Reported-by: Christoph Hellwig <hch@infradead.org>
Acked-by: Rik van Riel <riel@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-10-27 18:03:05 -07:00
Linus Torvalds
e404f91ed2 Merge git://git.kernel.org/pub/scm/linux/kernel/git/cmetcalf/linux-tile
* git://git.kernel.org/pub/scm/linux/kernel/git/cmetcalf/linux-tile:
  arch/tile: convert a BUG_ON to BUILD_BUG_ON
  arch/tile: make ptrace() work properly for TILE-Gx COMPAT mode
  arch/tile: support new info op generated by compiler
  arch/tile: minor whitespace/naming changes for string support files
  arch/tile: enable single-step support for TILE-Gx
  arch/tile: parameterize system PLs to support KVM port
  arch/tile: add Tilera's <arch/sim.h> header as an open-source header
  arch/tile: Bomb C99 comments to C89 comments in tile's <arch/sim_def.h>
  arch/tile: prevent corrupt top frame from causing backtracer runaway
  arch/tile: various top-level Makefile cleanups
  arch/tile: change lower bound on syscall error return to -4095
  arch/tile: properly export __mb_incoherent for modules
  arch/tile: provide a definition of MAP_STACK
  kmemleak: add TILE to the list of supported architectures.
  char: hvc: check for error case
  arch/tile: Add a warning if we try to allocate too much vmalloc memory.
  arch/tile: update some comments to clarify register usage.
  arch/tile: use better "punctuation" for VMSPLIT_3_5G and friends
  arch/tile: Use <asm-generic/syscalls.h>
  tile: replace some BUG_ON checks with BUILD_BUG_ON checks
2010-10-26 17:25:38 -07:00
Peter Zijlstra
ece0e2b640 mm: remove pte_*map_nested()
Since we no longer need to provide KM_type, the whole pte_*map_nested()
API is now redundant, remove it.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Acked-by: Chris Metcalf <cmetcalf@tilera.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: David Miller <davem@davemloft.net>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-10-26 16:52:08 -07:00
Peter Zijlstra
3e4d3af501 mm: stack based kmap_atomic()
Keep the current interface but ignore the KM_type and use a stack based
approach.

The advantage is that we get rid of crappy code like:

	#define __KM_PTE			\
		(in_nmi() ? KM_NMI_PTE : 	\
		 in_irq() ? KM_IRQ_PTE :	\
		 KM_PTE0)

and in general can stop worrying about what context we're in and what kmap
slots might be appropriate for that.

The downside is that FRV kmap_atomic() gets more expensive.

For now we use a CPP trick suggested by Andrew:

  #define kmap_atomic(page, args...) __kmap_atomic(page)

to avoid having to touch all kmap_atomic() users in a single patch.

[ not compiled on:
  - mn10300: the arch doesn't actually build with highmem to begin with ]

[akpm@linux-foundation.org: coding-style fixes]
[akpm@linux-foundation.org: fix up drivers/gpu/drm/i915/intel_overlay.c]
Acked-by: Rik van Riel <riel@redhat.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Acked-by: Chris Metcalf <cmetcalf@tilera.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: David Miller <davem@davemloft.net>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Dave Airlie <airlied@linux.ie>
Cc: Li Zefan <lizf@cn.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-10-26 16:52:08 -07:00
Linus Torvalds
db08bf0877 Merge git://git.kernel.org/pub/scm/linux/kernel/git/arnd/asm-generic
* git://git.kernel.org/pub/scm/linux/kernel/git/arnd/asm-generic:
  asm-generic/io.h: allow people to override individual funcs
  bitops: remove duplicated extern declarations
  bitops: make asm-generic/bitops/find.h more generic
  asm-generic: kdebug.h: Checkpatch cleanup
  asm-generic: fcntl: make exported headers use strict posix types
  asm-generic: cmpxchg does not handle non-long arguments
  asm-generic: make atomic_add_unless a function
2010-10-22 11:17:06 -07:00
Linus Torvalds
092e0e7e52 Merge branch 'llseek' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/bkl
* 'llseek' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/bkl:
  vfs: make no_llseek the default
  vfs: don't use BKL in default_llseek
  llseek: automatically add .llseek fop
  libfs: use generic_file_llseek for simple_attr
  mac80211: disallow seeks in minstrel debug code
  lirc: make chardev nonseekable
  viotape: use noop_llseek
  raw: use explicit llseek file operations
  ibmasmfs: use generic_file_llseek
  spufs: use llseek in all file operations
  arm/omap: use generic_file_llseek in iommu_debug
  lkdtm: use generic_file_llseek in debugfs
  net/wireless: use generic_file_llseek in debugfs
  drm: use noop_llseek
2010-10-22 10:52:56 -07:00
Linus Torvalds
e36f561a2c Merge git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-2.6-irqflags
* git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-2.6-irqflags:
  Fix IRQ flag handling naming
  MIPS: Add missing #inclusions of <linux/irq.h>
  smc91x: Add missing #inclusion of <linux/irq.h>
  Drop a couple of unnecessary asm/system.h inclusions
  SH: Add missing consts to sys_execve() declaration
  Blackfin: Rename IRQ flags handling functions
  Blackfin: Add missing dep to asm/irqflags.h
  Blackfin: Rename DES PC2() symbol to avoid collision
  Blackfin: Split the BF532 BFIN_*_FIO_FLAG() functions to their own header
  Blackfin: Split PLL code from mach-specific cdef headers
2010-10-21 14:37:27 -07:00
Chris Metcalf
e18105c128 arch/tile: convert a BUG_ON to BUILD_BUG_ON
Inspired by Akinobu Mita's cleanup work.

Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
2010-10-15 15:40:03 -04:00
Chris Metcalf
ce7f2a3967 arch/tile: make ptrace() work properly for TILE-Gx COMPAT mode
Previously, we tried to pass 64-bit arguments through the
"COMPAT" mode 32-bit syscall API, which turned out not to work
well.  Now we just use straight 32-bit arguments in COMPAT mode,
thus requiring individual registers to be read/written with
two syscalls.  Of course this is uncommon, since usually all
the registers are read or written at once.

The restructuring applies to all the tile platforms, but is
plausibly better than the original code in any case.

Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
2010-10-15 15:39:44 -04:00
Chris Metcalf
c569cac8b6 arch/tile: support new info op generated by compiler
This just syncs the backtracing support in the kernel to the
upstream backtrace library.

Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
2010-10-15 15:39:25 -04:00
Chris Metcalf
29507663df arch/tile: minor whitespace/naming changes for string support files
Our internal process shares memcpy, memset, etc., with libc, and
we did some minor tweaking as part of moving from uclibc to glibc,
which is now reflected in the kernel versions of these files.

There are no semantic changes in this commit, just whitespace
(memcpy_32.S now properly uses tabs), naming (memmove.c instead
of memmove_32.c, since TILE-Gx shares the file with TILEPro),
and a couple of other minor tweaks.

Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
2010-10-15 15:38:54 -04:00
Chris Metcalf
233325b949 arch/tile: enable single-step support for TILE-Gx
This is not quite the complete support, since we're not yet shipping
intvec_64.S, but it is the support relevant to the set of files we are
currently shipping, and makes it easier to track changes between
our internal sources and our public GIT repository.

Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
2010-10-15 15:38:26 -04:00
Chris Metcalf
a78c942df6 arch/tile: parameterize system PLs to support KVM port
While not a port to KVM (yet), this change modifies the kernel
to be able to build either at PL1 or at PL2 with a suitable
config switch.  Pushing up this change avoids handling branch
merge issues going forward with the KVM work.

Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
2010-10-15 15:38:09 -04:00
Chris Metcalf
bf65e440e8 arch/tile: add Tilera's <arch/sim.h> header as an open-source header
This change adds one of the Tilera standard <arch> headers to the set
of headers shipped with Linux.  The <arch/sim.h> header provides
methods for programmatically interacting with the Tilera simulator.

The current <arch/sim.h> provides inline assembly for the _sim_syscall
function, so the declaration and definition previously provided
manually in Linux are no longer needed.  We now use the standard
sim_validate_lines_evicted() method from <arch/sim.h> rather than
rolling our own direct call to sim_syscall().

Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
2010-10-15 15:36:54 -04:00
Chris Metcalf
4fe938c513 arch/tile: Bomb C99 comments to C89 comments in tile's <arch/sim_def.h>
Also, sync the file up the upstream version (an additional #define).

Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
2010-10-15 15:35:25 -04:00
Arnd Bergmann
6038f373a3 llseek: automatically add .llseek fop
All file_operations should get a .llseek operation so we can make
nonseekable_open the default for future file operations without a
.llseek pointer.

The three cases that we can automatically detect are no_llseek, seq_lseek
and default_llseek. For cases where we can we can automatically prove that
the file offset is always ignored, we use noop_llseek, which maintains
the current behavior of not returning an error from a seek.

New drivers should normally not use noop_llseek but instead use no_llseek
and call nonseekable_open at open time.  Existing drivers can be converted
to do the same when the maintainer knows for certain that no user code
relies on calling seek on the device file.

The generated code is often incorrectly indented and right now contains
comments that clarify for each added line why a specific variant was
chosen. In the version that gets submitted upstream, the comments will
be gone and I will manually fix the indentation, because there does not
seem to be a way to do that using coccinelle.

Some amount of new code is currently sitting in linux-next that should get
the same modifications, which I will do at the end of the merge window.

Many thanks to Julia Lawall for helping me learn to write a semantic
patch that does all this.

===== begin semantic patch =====
// This adds an llseek= method to all file operations,
// as a preparation for making no_llseek the default.
//
// The rules are
// - use no_llseek explicitly if we do nonseekable_open
// - use seq_lseek for sequential files
// - use default_llseek if we know we access f_pos
// - use noop_llseek if we know we don't access f_pos,
//   but we still want to allow users to call lseek
//
@ open1 exists @
identifier nested_open;
@@
nested_open(...)
{
<+...
nonseekable_open(...)
...+>
}

@ open exists@
identifier open_f;
identifier i, f;
identifier open1.nested_open;
@@
int open_f(struct inode *i, struct file *f)
{
<+...
(
nonseekable_open(...)
|
nested_open(...)
)
...+>
}

@ read disable optional_qualifier exists @
identifier read_f;
identifier f, p, s, off;
type ssize_t, size_t, loff_t;
expression E;
identifier func;
@@
ssize_t read_f(struct file *f, char *p, size_t s, loff_t *off)
{
<+...
(
   *off = E
|
   *off += E
|
   func(..., off, ...)
|
   E = *off
)
...+>
}

@ read_no_fpos disable optional_qualifier exists @
identifier read_f;
identifier f, p, s, off;
type ssize_t, size_t, loff_t;
@@
ssize_t read_f(struct file *f, char *p, size_t s, loff_t *off)
{
... when != off
}

@ write @
identifier write_f;
identifier f, p, s, off;
type ssize_t, size_t, loff_t;
expression E;
identifier func;
@@
ssize_t write_f(struct file *f, const char *p, size_t s, loff_t *off)
{
<+...
(
  *off = E
|
  *off += E
|
  func(..., off, ...)
|
  E = *off
)
...+>
}

@ write_no_fpos @
identifier write_f;
identifier f, p, s, off;
type ssize_t, size_t, loff_t;
@@
ssize_t write_f(struct file *f, const char *p, size_t s, loff_t *off)
{
... when != off
}

@ fops0 @
identifier fops;
@@
struct file_operations fops = {
 ...
};

@ has_llseek depends on fops0 @
identifier fops0.fops;
identifier llseek_f;
@@
struct file_operations fops = {
...
 .llseek = llseek_f,
...
};

@ has_read depends on fops0 @
identifier fops0.fops;
identifier read_f;
@@
struct file_operations fops = {
...
 .read = read_f,
...
};

@ has_write depends on fops0 @
identifier fops0.fops;
identifier write_f;
@@
struct file_operations fops = {
...
 .write = write_f,
...
};

@ has_open depends on fops0 @
identifier fops0.fops;
identifier open_f;
@@
struct file_operations fops = {
...
 .open = open_f,
...
};

// use no_llseek if we call nonseekable_open
////////////////////////////////////////////
@ nonseekable1 depends on !has_llseek && has_open @
identifier fops0.fops;
identifier nso ~= "nonseekable_open";
@@
struct file_operations fops = {
...  .open = nso, ...
+.llseek = no_llseek, /* nonseekable */
};

@ nonseekable2 depends on !has_llseek @
identifier fops0.fops;
identifier open.open_f;
@@
struct file_operations fops = {
...  .open = open_f, ...
+.llseek = no_llseek, /* open uses nonseekable */
};

// use seq_lseek for sequential files
/////////////////////////////////////
@ seq depends on !has_llseek @
identifier fops0.fops;
identifier sr ~= "seq_read";
@@
struct file_operations fops = {
...  .read = sr, ...
+.llseek = seq_lseek, /* we have seq_read */
};

// use default_llseek if there is a readdir
///////////////////////////////////////////
@ fops1 depends on !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
identifier fops0.fops;
identifier readdir_e;
@@
// any other fop is used that changes pos
struct file_operations fops = {
... .readdir = readdir_e, ...
+.llseek = default_llseek, /* readdir is present */
};

// use default_llseek if at least one of read/write touches f_pos
/////////////////////////////////////////////////////////////////
@ fops2 depends on !fops1 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
identifier fops0.fops;
identifier read.read_f;
@@
// read fops use offset
struct file_operations fops = {
... .read = read_f, ...
+.llseek = default_llseek, /* read accesses f_pos */
};

@ fops3 depends on !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
identifier fops0.fops;
identifier write.write_f;
@@
// write fops use offset
struct file_operations fops = {
... .write = write_f, ...
+	.llseek = default_llseek, /* write accesses f_pos */
};

// Use noop_llseek if neither read nor write accesses f_pos
///////////////////////////////////////////////////////////

@ fops4 depends on !fops1 && !fops2 && !fops3 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
identifier fops0.fops;
identifier read_no_fpos.read_f;
identifier write_no_fpos.write_f;
@@
// write fops use offset
struct file_operations fops = {
...
 .write = write_f,
 .read = read_f,
...
+.llseek = noop_llseek, /* read and write both use no f_pos */
};

@ depends on has_write && !has_read && !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
identifier fops0.fops;
identifier write_no_fpos.write_f;
@@
struct file_operations fops = {
... .write = write_f, ...
+.llseek = noop_llseek, /* write uses no f_pos */
};

@ depends on has_read && !has_write && !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
identifier fops0.fops;
identifier read_no_fpos.read_f;
@@
struct file_operations fops = {
... .read = read_f, ...
+.llseek = noop_llseek, /* read uses no f_pos */
};

@ depends on !has_read && !has_write && !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
identifier fops0.fops;
@@
struct file_operations fops = {
...
+.llseek = noop_llseek, /* no read or write fn */
};
===== End semantic patch =====

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Cc: Julia Lawall <julia@diku.dk>
Cc: Christoph Hellwig <hch@infradead.org>
2010-10-15 15:53:27 +02:00
Chris Metcalf
dabe98c972 arch/tile: prevent corrupt top frame from causing backtracer runaway
The backtracer will normally cut itself off after 100 frames anyway,
but it's messy.  With this change we notice that the frame being
reported is the same as the last one, and cut off the dump with a
message similar to what gdb displays in the same circumstance.

Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
2010-10-14 15:19:04 -04:00
Chris Metcalf
45123f7e74 arch/tile: various top-level Makefile cleanups
Avoid a compile failure if CONFIG_DEBUG_EXTRA_FLAGS is empty ("");
provide an "install" hook as well as a matching archhelp target;
and some minor whitespace cleanup.

Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
2010-10-14 15:16:59 -04:00
Chris Metcalf
a4dbc5ee52 arch/tile: change lower bound on syscall error return to -4095
Previously we were using -1023, which is fine for normal syscall
error returns, but the common value in use for other platforms
is -4095, and one Tilera-specific driver does use values in the
-1100 range, so tickled this bug.

Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
2010-10-14 15:14:29 -04:00
Chris Metcalf
13c9d5a630 arch/tile: properly export __mb_incoherent for modules
Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
2010-10-14 15:12:55 -04:00
Chris Metcalf
bbacff94d0 arch/tile: provide a definition of MAP_STACK
It's convenient for userspace (in particular, glibc) to find a
definition of MAP_STACK.  We use MAP_GROWSDOWN as an alias since
that's appropriate for the main stack, and since our current
allocation of mmap flags bits is running a bit short otherwise.

Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
2010-10-14 15:09:02 -04:00
Chris Metcalf
77d233036e arch/tile: Add a warning if we try to allocate too much vmalloc memory.
Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
2010-10-14 14:47:35 -04:00
Chris Metcalf
d6f0f22c3c arch/tile: update some comments to clarify register usage.
Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
2010-10-14 14:42:58 -04:00
Chris Metcalf
5592840ba8 arch/tile: use better "punctuation" for VMSPLIT_3_5G and friends
Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
2010-10-14 14:36:50 -04:00
Chris Metcalf
d929b6aeaa arch/tile: Use <asm-generic/syscalls.h>
With this change we now include <asm-generic/syscalls.h> into the "tile"
version of the header.  To take full advantage of the prototypes there,
we also change our naming convention for "struct pt_regs *" syscalls so
that, e.g., _sys_execve() is the "true" syscall entry, which sets the
appropriate register to point to the pt_regs before calling sys_execve().

While doing this I realized I no longer needed the fork and vfork
entry point stubs, since those functions aren't in the generic
syscall ABI, so I removed them as well.

Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
2010-10-14 14:34:33 -04:00
Chris Metcalf
ce0ecc8abf Merge branch 'master' into for-linus 2010-10-14 11:57:29 -04:00