kunmap_atomic() is currently at level -4 on Rusty's "Hard To Misuse"
list[1] ("Follow common convention and you'll get it wrong"), except in
some architectures when CONFIG_DEBUG_HIGHMEM is set[2][3].
kunmap() takes a pointer to a struct page; kunmap_atomic(), however, takes
takes a pointer to within the page itself. This seems to once in a while
trip people up (the convention they are following is the one from
kunmap()).
Make it much harder to misuse, by moving it to level 9 on Rusty's list[4]
("The compiler/linker won't let you get it wrong"). This is done by
refusing to build if the type of its first argument is a pointer to a
struct page.
The real kunmap_atomic() is renamed to kunmap_atomic_notypecheck()
(which is what you would call in case for some strange reason calling it
with a pointer to a struct page is not incorrect in your code).
The previous version of this patch was compile tested on x86-64.
[1] http://ozlabs.org/~rusty/index.cgi/tech/2008-04-01.html
[2] In these cases, it is at level 5, "Do it right or it will always
break at runtime."
[3] At least mips and powerpc look very similar, and sparc also seems to
share a common ancestor with both; there seems to be quite some
degree of copy-and-paste coding here. The include/asm/highmem.h file
for these three archs mention x86 CPUs at its top.
[4] http://ozlabs.org/~rusty/index.cgi/tech/2008-03-30.html
[5] As an aside, could someone tell me why mn10300 uses unsigned long as
the first parameter of kunmap_atomic() instead of void *?
Signed-off-by: Cesar Eduardo Barros <cesarb@cesarb.net>
Cc: Russell King <linux@arm.linux.org.uk> (arch/arm)
Cc: Ralf Baechle <ralf@linux-mips.org> (arch/mips)
Cc: David Howells <dhowells@redhat.com> (arch/frv, arch/mn10300)
Cc: Koichi Yasutake <yasutake.koichi@jp.panasonic.com> (arch/mn10300)
Cc: Kyle McMartin <kyle@mcmartin.ca> (arch/parisc)
Cc: Helge Deller <deller@gmx.de> (arch/parisc)
Cc: "James E.J. Bottomley" <jejb@parisc-linux.org> (arch/parisc)
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> (arch/powerpc)
Cc: Paul Mackerras <paulus@samba.org> (arch/powerpc)
Cc: "David S. Miller" <davem@davemloft.net> (arch/sparc)
Cc: Thomas Gleixner <tglx@linutronix.de> (arch/x86)
Cc: Ingo Molnar <mingo@redhat.com> (arch/x86)
Cc: "H. Peter Anvin" <hpa@zytor.com> (arch/x86)
Cc: Arnd Bergmann <arnd@arndb.de> (include/asm-generic)
Cc: Rusty Russell <rusty@rustcorp.com.au> ("Hard To Misuse" list)
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (162 commits)
tracing/kprobes: unregister_trace_probe needs to be called under mutex
perf: expose event__process function
perf events: Fix mmap offset determination
perf, powerpc: fsl_emb: Restore setting perf_sample_data.period
perf, powerpc: Convert the FSL driver to use local64_t
perf tools: Don't keep unreferenced maps when unmaps are detected
perf session: Invalidate last_match when removing threads from rb_tree
perf session: Free the ref_reloc_sym memory at the right place
x86,mmiotrace: Add support for tracing STOS instruction
perf, sched migration: Librarize task states and event headers helpers
perf, sched migration: Librarize the GUI class
perf, sched migration: Make the GUI class client agnostic
perf, sched migration: Make it vertically scrollable
perf, sched migration: Parameterize cpu height and spacing
perf, sched migration: Fix key bindings
perf, sched migration: Ignore unhandled task states
perf, sched migration: Handle ignored migrate out events
perf: New migration tool overview
tracing: Drop cpparg() macro
perf: Use tracepoint_synchronize_unregister() to flush any pending tracepoint call
...
Fix up trivial conflicts in Makefile and drivers/cpufreq/cpufreq.c
* 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jwessel/linux-2.6-kgdb:
debug_core,kdb: fix crash when arch does not have single step
kgdb,x86: use macro HBP_NUM to replace magic number 4
kgdb,mips: remove unused kgdb_cpu_doing_single_step operations
mm,kdb,kgdb: Add a debug reference for the kdb kmap usage
KGDB: Remove set but unused newPC
ftrace,kdb: Allow dumping a specific cpu's buffer with ftdump
ftrace,kdb: Extend kdb to be able to dump the ftrace buffer
kgdb,powerpc: Replace hardcoded offset by BREAK_INSTR_SIZE
arm,kgdb: Add ability to trap into debugger on notify_die
gdbstub: do not directly use dbg_reg_def[] in gdb_cmd_reg_set()
gdbstub: Implement gdbserial 'p' and 'P' packets
kgdb,arm: Individual register get/set for arm
kgdb,mips: Individual register get/set for mips
kgdb,x86: Individual register get/set for x86
kgdb,kdb: individual register set and and get API
gdbstub: Optimize kgdb's "thread:" response for the gdb serial protocol
kgdb: remove custom hex_to_bin()implementation
Implement the ability to individually get and set registers for kdb
and kgdb for arm.
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
CC: Russell King <linux@arm.linux.org.uk>
CC: linux-arm-kernel@lists.infradead.org
* 'devel' of master.kernel.org:/home/rmk/linux-2.6-arm: (291 commits)
ARM: AMBA: Add pclk support to AMBA bus infrastructure
ARM: 6278/2: fix regression in RealView after the introduction of pclk
ARM: 6277/1: mach-shmobile: Allow users to select HZ, default to 128
ARM: 6276/1: mach-shmobile: remove duplicate NR_IRQS_LEGACY
ARM: 6246/1: mmci: support larger MMCIDATALENGTH register
ARM: 6245/1: mmci: enable hardware flow control on Ux500 variants
ARM: 6244/1: mmci: add variant data and default MCICLOCK support
ARM: 6243/1: mmci: pass power_mode to the translate_vdd callback
ARM: 6274/1: add global control registers definition header file for nuc900
mx2_camera: fix type of dma buffer virtual address pointer
mx2_camera: Add soc_camera support for i.MX25/i.MX27
arm/imx/gpio: add spinlock protection
ARM: Add support for the LPC32XX arch
ARM: LPC32XX: Arch config menu supoport and makefiles
ARM: LPC32XX: Phytec 3250 platform support
ARM: LPC32XX: Misc support functions
ARM: LPC32XX: Serial support code
ARM: LPC32XX: System suspend support
ARM: LPC32XX: GPIO, timer, and IRQ drivers
ARM: LPC32XX: Clock driver
...
The ioread/iowrite accessors also need barriers as they're used in
place of readl/writel et.al. in portable drivers. Create __iormb()
and __iowmb() which are conditionally defined to be barriers dependent
on ARM_DMA_MEM_BUFFERABLE, and always use these macros in the accessors.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
When the coherent DMA buffers are mapped as Normal Non-cacheable
(ARM_DMA_MEM_BUFFERABLE enabled), buffer accesses are no longer ordered
with Device memory accesses causing failures in device drivers that do
not use the mandatory memory barriers before starting a DMA transfer.
LKML discussions led to the conclusion that such barriers have to be
added to the I/O accessors:
http://thread.gmane.org/gmane.linux.kernel/683509/focus=686153http://thread.gmane.org/gmane.linux.ide/46414http://thread.gmane.org/gmane.linux.kernel.cross-arch/5250
This patch introduces a wmb() barrier to the write*() I/O accessors to
handle the situations where Normal Non-cacheable writes are still in the
processor (or L2 cache controller) write buffer before a DMA transfer
command is issued. For the read*() accessors, a rmb() is introduced
after the I/O to avoid speculative loads where the driver polls for a
DMA transfer ready bit.
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
This patch introduces readl*_relaxed()/write*_relaxed() as the main I/O
accessors (when __mem_pci is defined). The standard read*()/write*()
macros are now based on the relaxed accessors.
This patch is in preparation for a subsequent patch which adds barriers
to the I/O accessors.
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Add one more parameter to hook_fault_code() to be able to set 'code'
field of struct fsr_info.
Signed-off-by: Kirill A. Shutemov <kirill@shutemov.name>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
This changes the TCM handling so that a fixed area is reserved at
0xfffe0000-0xfffeffff for TCM. This areas is used by XScale but
XScale does not have TCM so the mechanisms are mutually exclusive.
This change is needed to make TCM detection more dynamic while
still being able to compile code into it, and is a must for the
unified ARM goals: the current TCM allocation at different places
in memory for each machine would be a nightmare if you want to
compile a single image for more than one machine with TCM so it
has to be nailed down in one place.
Signed-off-by: Linus Walleij <linus.walleij@stericsson.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
CC kernel/elfcore.o
In file included from include/linux/elf.h:7,
from kernel/elfcore.c:1:
arch/arm/include/asm/elf.h:124: warning: 'struct mm_struct' declared inside parameter list
arch/arm/include/asm/elf.h:124: warning: its scope is only this definition or declaration, which is probably not what you want
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
The earlier TCM memory regions were mapped as MT_MEMORY_UNCACHED
which doesn't really work on platforms supporting the new v6
features like the NX bit. Add unique MT_MEMORY_[I|D]TCM types
instead.
Cc: Nicolas Pitre <nico@fluxnic.net>
Signed-off-by: Linus Walleij <linus.walleij@stericsson.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Add private_data pointer to the pci_sys_data, this pointer can be
used for holding platform specific data for each pci controller.
Signed-off-by: Saeed Bishara <saeed@marvell.com>
Signed-off-by: Nicolas Pitre <nico@fluxnic.net>
Move the platform specific bootmem memory reservations out of
arch/arm/mm/mmu.c into their respective platform files.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Everything should now be using sparsemem rather than discontigmem, so
remove the code supporting discontigmem from ARM.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Implement machine specific function crash_setup_regs() which is
responsible for storing machine state when crash occured.
Signed-off-by: Mika Westerberg <ext-mika.1.westerberg@nokia.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
The TLS register is only available on ARM1136 r1p0 and later.
Set HWCAP_TLS flags if hardware TLS is available and test for
it if CONFIG_CPU_32v6K is not set for V6.
Note that we set the TLS instruction in __kuser_get_tls
dynamically as suggested by Jamie Lokier <jamie@shareable.org>.
Also the __switch_to code is optimized out in most cases as
suggested by Nicolas Pitre <nico@fluxnic.net>.
Reviewed-by: Nicolas Pitre <nicolas.pitre@linaro.org>
Signed-off-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
MVFR0 and MVFR1 are only available starting with ARM1136 r1p0 release
according to "B.5 VFP changes" in DDI0211F_arm1136_r1p0_trm.pdf. This is
also when TLS register got added, so we can use HAS_TLS also to test for
MVFR0 and MVFR1.
Otherwise VFPFMRX and VFPFMXR access fails and we get:
Internal error: Oops - undefined instruction: 0 [#1]
PC is at no_old_VFP_process+0x8/0x3c
LR is at __und_svc+0x48/0x80
...
Signed-off-by: Tony Lindgren <tony@atomide.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
This patch enables the HAVE_REGS_AND_STACK_ACCESS_API option
for ARM which is required by the kprobe events tracer. Code based
on the PowerPC port.
Cc: Jean Pihet <jpihet@mvista.com>
Tested-by: Jamie Iles <jamie.iles@picochip.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
So to allow NR_IRQS to be dynamic and platforms to specify the number
of IRQs really needed.
Acked-by: Paul Mundt <lethal@linux-sh.org>
Signed-off-by: Eric Miao <eric.y.miao@gmail.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
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>
Linux expects that if a CPU modifies a memory location, then that
modification will eventually become visible to other CPUs in the system.
On an ARM11MPCore processor, loads are prioritised over stores so it is
possible for a store operation to be postponed if a polling loop immediately
follows it. If the variable being polled indirectly depends on the outstanding
store [for example, another CPU may be polling the variable that is pending
modification] then there is the potential for deadlock if interrupts are
disabled. This deadlock occurs in the KGDB testsuire when executing on an
SMP ARM11MPCore configuration.
This patch changes the definition of cpu_relax() to smp_mb() for ARMv6 cores,
forcing a flushing of the write buffer on SMP systems before the next load
takes place. If the Kernel is not compiled for SMP support, this will expand
to a barrier() as before.
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
This is the very basic stuff without the changing canary upon
task switch yet. Just the Kconfig option and a constant canary
value initialized at boot time.
Signed-off-by: Nicolas Pitre <nicolas.pitre@linaro.org>
For this feature to take effect, CONFIG_COMPAT_BRK must be turned
off. This can safely be turned off for any EABI user space versions.
Signed-off-by: Nicolas Pitre <nicolas.pitre@linaro.org>
gpio must be int, not u16, otherwise -1 isn't recognised
by gpio_is_valid().
Signed-off-by: Steve Bennett <steveb@workware.net.au>
Signed-off-by: Eric Miao <eric.y.miao@gmail.com>
On 64bit, local_t is of size long, and thus we make local64_t an alias.
On 32bit, we fall back to atomic64_t. (architecture can provide optimized
32-bit version)
(This new facility is to be used by perf events optimizations.)
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: linux-arch@vger.kernel.org
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
LKML-Reference: <new-submission>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
There are more architectures that don't support ARCH_HAS_SG_CHAIN than
those that support it. This removes removes ARCH_HAS_SG_CHAIN in
asm-generic/scatterlist.h and lets arhictectures to define it.
It's clearer than defining ARCH_HAS_SG_CHAIN asm-generic/scatterlist.h and
undefing it in arhictectures that don't support it.
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This patch contains the hooks and instrumentation into kernel which
live outside the kernel/debug directory, which the kdb core
will call to run commands like lsmod, dmesg, bt etc...
CC: linux-arch@vger.kernel.org
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
Signed-off-by: Martin Hicks <mort@sgi.com>
This patch adds support for 10 hardirq bits to
the ARM architecture. Needed by the SH-Mobile
ARM processor sh7372 that has more than 512 IRQs.
Signed-off-by: Magnus Damm <damm@opensource.se>
Acked-by: Eric Miao <eric.y.miao@gmail.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial: (44 commits)
vlynq: make whole Kconfig-menu dependant on architecture
add descriptive comment for TIF_MEMDIE task flag declaration.
EEPROM: max6875: Header file cleanup
EEPROM: 93cx6: Header file cleanup
EEPROM: Header file cleanup
agp: use NULL instead of 0 when pointer is needed
rtc-v3020: make bitfield unsigned
PCI: make bitfield unsigned
jbd2: use NULL instead of 0 when pointer is needed
cciss: fix shadows sparse warning
doc: inode uses a mutex instead of a semaphore.
uml: i386: Avoid redefinition of NR_syscalls
fix "seperate" typos in comments
cocbalt_lcdfb: correct sections
doc: Change urls for sparse
Powerpc: wii: Fix typo in comment
i2o: cleanup some exit paths
Documentation/: it's -> its where appropriate
UML: Fix compiler warning due to missing task_struct declaration
UML: add kernel.h include to signal.c
...
* 'devel' of master.kernel.org:/home/rmk/linux-2.6-arm: (224 commits)
ARM: remove 'select GENERIC_TIME'
ARM: 6136/1: ARCH_REQUIRE_GPIOLIB selects GENERIC_GPIO
ARM: 6074/1: oprofile: convert from sysdev to platform device
ARM: 6073/1: oprofile: remove old files and update KConfig
ARM: 6072/1: oprofile: use perf-events framework as backend
ARM: 6071/1: perf-events: allow modules to query the number of hardware counters
ARM: 6070/1: perf-events: add support for xscale PMUs
ARM: 6069/1: perf-events: use numeric ID to identify PMU
ARM: 6064/1: pmu: register IRQs at runtime
ARM: Optionally allow ARMv6 to use 'normal, bufferable' memory for DMA
ARM: 6134/1: Handle instruction cache maintenance fault properly
ARM: nwfpe: allow debugging output to be configured at runtime
ARM: rename mach_cpu_disable() to platform_cpu_disable()
ARM: 6132/1: PL330: Add common core driver
ARM: 6094/1: Extend cache-l2x0 to support the 16-way PL310
ARM: Move memory mapping into mmu.c
ARM: Ensure meminfo is sorted prior to sanity_check_meminfo
ARM: Remove useless linux/bootmem.h includes
ARM: convert /proc/cpu/aligment to seq_file
arm: use asm-generic/scatterlist.h
...
In preparation for removing volatile from the atomic_t definition, this
patch adds a volatile cast to all the atomic read functions.
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
For OProfile to initialise oprofilefs correctly, it needs to know
the number of counters it can represent.
This patch adds a function to the ARM perf-events backend to return
the number of hardware counters available for the current PMU.
Cc: Jamie Iles <jamie.iles@picochip.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
The ARM perf-events framework provides support for a number of different
PMUs using struct arm_pmu. The char *name field of this struct can be
used to identify the PMU, but this is cumbersome if used outside of perf.
This patch replaces the name string for a PMU with an enum, which holds
a unique ID for the PMU being represented. This ID can be used to index
an array of names within perf, so no functionality is lost. The presence
of the ID field, allows other kernel subsystems [currently oprofile] to
use their own mappings for the PMU name.
Cc: Jean Pihet <jpihet@mvista.com>
Acked-by: Jamie Iles <jamie.iles@picochip.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
