path: root/arch/arm/kernel/entry-armv.S
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2012-07-31ARM: Fix undefined instruction exception handlingRussell King
While trying to get a v3.5 kernel booted on the cubox, I noticed that VFP does not work correctly with VFP bounce handling. This is because of the confusion over 16-bit vs 32-bit instructions, and where PC is supposed to point to. The rule is that FP handlers are entered with regs->ARM_pc pointing at the _next_ instruction to be executed. However, if the exception is not handled, regs->ARM_pc points at the faulting instruction. This is easy for ARM mode, because we know that the next instruction and previous instructions are separated by four bytes. This is not true of Thumb2 though. Since all FP instructions are 32-bit in Thumb2, it makes things easy. We just need to select the appropriate adjustment. Do this by moving the adjustment out of do_undefinstr() into the assembly code, as only the assembly code knows whether it's dealing with a 32-bit or 16-bit instruction. Cc: <stable@vger.kernel.org> Acked-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2012-06-16ARM: 7425/1: extable: ensure fixup entries are 4-byte alignedWill Deacon
Fixup entries in the kernel exception tables should be 4-byte aligned since we return directly to them when handling a faulting instruction in the kernel. This patch adds the missing align directives to the fixup entries. Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2012-05-05ARM: Remove support for ARMv3 ARM610 and ARM710 CPUsRussell King
This patch removes support for ARMv3 CPUs, which haven't worked properly for quite some time (see the FIXME comment in arch/arm/mm/fault.c). The only V3 parts left is the cache model for ARMv3, which is needed for some odd reason by ARM740T CPUs, and being able to build with -march=armv3, which is required for the RiscPC platform due to its bus structure. Acked-by: Will Deacon <will.deacon@arm.com> Acked-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2012-03-29Merge tag 'cleanup2' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc Pull "ARM: cleanups of io includes" from Olof Johansson: "Rob Herring has done a sweeping change cleaning up all of the mach/io.h includes, moving some of the oft-repeated macros to a common location and removing a bunch of boiler plate. This is another step closer to a common zImage for multiple platforms." Fix up various fairly trivial conflicts (<mach/io.h> removal vs changes around it, tegra localtimer.o is *still* gone, yadda-yadda). * tag 'cleanup2' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc: (29 commits) ARM: tegra: Include assembler.h in sleep.S to fix build break ARM: pxa: use common IOMEM definition ARM: dma-mapping: convert ARCH_HAS_DMA_SET_COHERENT_MASK to kconfig symbol ARM: __io abuse cleanup ARM: create a common IOMEM definition ARM: iop13xx: fix missing declaration of iop13xx_init_early ARM: fix ioremap/iounmap for !CONFIG_MMU ARM: kill off __mem_pci ARM: remove bunch of now unused mach/io.h files ARM: make mach/io.h include optional ARM: clps711x: remove unneeded include of mach/io.h ARM: dove: add explicit include of dove.h to addr-map.c ARM: at91: add explicit include of hardware.h to uncompressor ARM: ep93xx: clean-up mach/io.h ARM: tegra: clean-up mach/io.h ARM: orion5x: clean-up mach/io.h ARM: davinci: remove unneeded mach/io.h include [media] davinci: remove includes of mach/io.h ARM: OMAP: Remove remaining includes for mach/io.h ARM: msm: clean-up mach/io.h ...
2012-03-28Merge tag 'split-asm_system_h-for-linus-20120328' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-asm_system Pull "Disintegrate and delete asm/system.h" from David Howells: "Here are a bunch of patches to disintegrate asm/system.h into a set of separate bits to relieve the problem of circular inclusion dependencies. I've built all the working defconfigs from all the arches that I can and made sure that they don't break. The reason for these patches is that I recently encountered a circular dependency problem that came about when I produced some patches to optimise get_order() by rewriting it to use ilog2(). This uses bitops - and on the SH arch asm/bitops.h drags in asm-generic/get_order.h by a circuituous route involving asm/system.h. The main difficulty seems to be asm/system.h. It holds a number of low level bits with no/few dependencies that are commonly used (eg. memory barriers) and a number of bits with more dependencies that aren't used in many places (eg. switch_to()). These patches break asm/system.h up into the following core pieces: (1) asm/barrier.h Move memory barriers here. This already done for MIPS and Alpha. (2) asm/switch_to.h Move switch_to() and related stuff here. (3) asm/exec.h Move arch_align_stack() here. Other process execution related bits could perhaps go here from asm/processor.h. (4) asm/cmpxchg.h Move xchg() and cmpxchg() here as they're full word atomic ops and frequently used by atomic_xchg() and atomic_cmpxchg(). (5) asm/bug.h Move die() and related bits. (6) asm/auxvec.h Move AT_VECTOR_SIZE_ARCH here. Other arch headers are created as needed on a per-arch basis." Fixed up some conflicts from other header file cleanups and moving code around that has happened in the meantime, so David's testing is somewhat weakened by that. We'll find out anything that got broken and fix it.. * tag 'split-asm_system_h-for-linus-20120328' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-asm_system: (38 commits) Delete all instances of asm/system.h Remove all #inclusions of asm/system.h Add #includes needed to permit the removal of asm/system.h Move all declarations of free_initmem() to linux/mm.h Disintegrate asm/system.h for OpenRISC Split arch_align_stack() out from asm-generic/system.h Split the switch_to() wrapper out of asm-generic/system.h Move the asm-generic/system.h xchg() implementation to asm-generic/cmpxchg.h Create asm-generic/barrier.h Make asm-generic/cmpxchg.h #include asm-generic/cmpxchg-local.h Disintegrate asm/system.h for Xtensa Disintegrate asm/system.h for Unicore32 [based on ver #3, changed by gxt] Disintegrate asm/system.h for Tile Disintegrate asm/system.h for Sparc Disintegrate asm/system.h for SH Disintegrate asm/system.h for Score Disintegrate asm/system.h for S390 Disintegrate asm/system.h for PowerPC Disintegrate asm/system.h for PA-RISC Disintegrate asm/system.h for MN10300 ...
2012-03-28Disintegrate asm/system.h for ARMDavid Howells
Disintegrate asm/system.h for ARM. Signed-off-by: David Howells <dhowells@redhat.com> cc: Russell King <linux@arm.linux.org.uk> cc: linux-arm-kernel@lists.infradead.org
2012-03-13ARM: create a common IOMEM definitionRob Herring
Several platforms create IOMEM defines for casting to 'void __iomem *', and other platforms are incorrectly using __io() macro for the same purpose. This creates a common definition and removes all the platform specific versions. Rather than try to make linux/io.h and asm/io.h assembly safe, the assembly version of IOMEM is moved into asm/assembler.h. Signed-off-by: Rob Herring <rob.herring@calxeda.com> Cc: Russell King <linux@arm.linux.org.uk> Cc: Sekhar Nori <nsekhar@ti.com> Cc: Kevin Hilman <khilman@ti.com> Acked-by: H Hartley Sweeten <hsweeten@visionengravers.com> Cc: Ryan Mallon <rmallon@gmail.com> Cc: Eric Miao <eric.y.miao@gmail.com> Cc: Haojian Zhuang <haojian.zhuang@marvell.com> Acked-by: David Brown <davidb@codeaurora.org> Cc: Daniel Walker <dwalker@fifo99.com> Cc: Bryan Huntsman <bryanh@codeaurora.org> Cc: Sascha Hauer <kernel@pengutronix.de> Cc: Shawn Guo <shawn.guo@linaro.org> Acked-by: Tony Lindgren <tony@atomide.com> Acked-by: Paul Walmsley <paul@pwsan.com> Acked-by: Viresh Kumar <viresh.kumar@st.com> Cc: Rajeev Kumar <rajeev-dlh.kumar@st.com> Cc: Colin Cross <ccross@android.com> Cc: Olof Johansson <olof@lixom.net> Cc: Stephen Warren <swarren@nvidia.com> Acked-by: Linus Walleij <linus.walleij@linaro.org> Acked-by: Arnd Bergmann <arnd@arndb.de>
2012-02-21ARM: make entry-macro.S depend on !MULTI_IRQ_HANDLERRob Herring
With the removal of disable_fiq on rpc and addition MULTI_IRQ_HANDLER, entry-macro.S is no longer needed for platforms that select MULTI_IRQ_HANDLER and the include of it can be conditional. Signed-off-by: Rob Herring <rob.herring@calxeda.com> Acked-by: Nicolas Pitre <nico@linaro.org> Acked-by: H Hartley Sweeten <hsweeten@visionengravers.com>
2012-02-03ARM: 7314/1: kuser: consistently use usr_ret for returning from helpersWill Deacon
__kuser_cmpxchg64 has a return path using bx lr to get back to the caller. This is actually ok since the code in question is predicated on CONFIG_CPU_32v6K, but for the sake of consistency using the usr_ret macro is probably better. Acked-by: Dave Martin <dave.martin@linaro.org> Acked-by: Nicolas Pitre <nico@linaro.org> Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2011-12-05Merge branch 'for-rmk' of ↵Russell King
git://git.kernel.org/pub/scm/linux/kernel/git/will/linux into devel-stable Conflicts: arch/arm/common/gic.c arch/arm/plat-omap/include/plat/common.h
2011-11-26ARM: 7170/2: fix compilation breakage in entry-armv.SGuennadi Liakhovetski
Fix compilation failure, when Thumb support is not enabled: arch/arm/kernel/entry-armv.S: Assembler messages: arch/arm/kernel/entry-armv.S:501: Error: backward ref to unknown label "2:" arch/arm/kernel/entry-armv.S:502: Error: backward ref to unknown label "3:" make[2]: *** [arch/arm/kernel/entry-armv.o] Error 1 Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de> Reviewed-by: Dave Martin <dave.martin@linaro.org> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2011-11-15ARM: Make global handler and CONFIG_MULTI_IRQ_HANDLER mutually exclusiveMarc Zyngier
Even when CONFIG_MULTI_IRQ_HANDLER is selected, the core code requires the arch_irq_handler_default macro to be defined as a fallback. It turns out nobody is using that particular feature as both PXA and shmobile have all their machine descriptors populated with the interrupt handler, leaving unused code (or empty macros) in their entry-macro.S file just to be able to compile entry-armv.S. Make CONFIG_MULTI_IRQ_HANDLER exclusive wrt arch_irq_handler_default, which allows to remove one test from the hot path. Also cleanup both PXA and shmobile entry-macro.S. Cc: Paul Mundt <lethal@linux-sh.org> Acked-by: Nicolas Pitre <nico@linaro.org> Acked-by: Eric Miao <eric.y.miao@gmail.com> Tested-by: Jamie Iles <jamie@jamieiles.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2011-10-17ARM: 7031/1: entry: Fix Thumb-2 undef handling for multi-CPU kernelsDave Martin
When v6 and >=v7 boards are supported in the same kernel, the __und_usr code currently makes a build-time assumption that Thumb-2 instructions occurring in userspace don't need to be supported. Strictly speaking this is incorrect. This patch fixes the above case by doing a run-time check on the CPU architecture in these cases. This only affects kernels which support v6 and >=v7 CPUs together: plain v6 and plain v7 kernels are unaffected. Signed-off-by: Dave Martin <dave.martin@linaro.org> Reviewed-by: Jon Medhurst <tixy@yxit.co.uk> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2011-10-17ARM: 7030/1: entry: Remove unnecessary masking when decoding Thumb-2 ↵Dave Martin
instructions When testing whether a Thumb-2 instruction is 32 bits long or not, the masking done in order to test bits 11-15 of the first instruction halfword won't affect the result of the comparison, so remove it. Signed-off-by: Dave Martin <dave.martin@linaro.org> Reviewed-by: Jon Medhurst <tixy@yxit.co.uk> Acked-by: Nicolas Pitre <nicolas.pitre@linaro.org> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2011-07-22Merge branch 'devel-stable' into for-nextRussell King
Conflicts: arch/arm/kernel/entry-armv.S
2011-07-02ARM: entry: no need to reload the SPSR value from struct pt_regsRussell King
The SVC IRQ, prefetch and data abort handlers preserve the SPSR value via r5 across the exception. Rather than re-loading it from pt_regs, use the preserved value instead. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2011-07-02ARM: entry: data abort: tail-call the main data abort handlerRussell King
Tail-call the main C data abort handler code from the per-CPU helper code. Update the comments in the code wrt the new calling and return register state. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2011-07-02ARM: entry: data abort: arrange for CPU abort helpers to take pc/psr in r4/r5Russell King
Re-jig the CPU abort helpers to take the PC/PSR in r4/r5 rather than r2/r3. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2011-07-02ARM: entry: prefetch abort: tail-call the main prefetch abort handlerRussell King
Tail-call the main C prefetch abort handler code from the per-CPU helper code. Also note that the helper function becomes ABI compliant in terms of the registers preserved. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2011-07-02ARM: entry: re-allocate registers in irq entry assembly macrosRussell King
This avoids the irq entry assembly corrupting r5, thereby allowing it to be preserved through to the svc exit code. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2011-07-02ARM: entry: consolidate trace_hardirqs_off into (svc|usr)_entry macrosRussell King
All handlers now call trace_hardirqs_off, so move this common code into the (svc|usr)_entry assembler macros. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2011-07-02ARM: entry: instrument usr exception handlers with irqsoff tracingRussell King
As we no longer re-enable interrupts in these exception handlers, add the irqsoff tracing calls to them so that the kernel tracks the state more accurately. Note that these calls are conditional on IRQSOFF_TRACER: kernel ----------> user ---------> kernel ^ irqs enabled ^ irqs disabled No kernel code can run on the local CPU until we've re-entered the kernel through one of the exception handlers - and userspace can not take any locks etc. So, the kernel doesn't care about the IRQ mask state while userspace is running unless we're doing IRQ off latency tracing. So, we can (and do) avoid the overhead of updating the IRQ mask state on every kernel->user and user->kernel transition. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2011-07-02ARM: entry: instrument svc undefined exception handler with irqtraceRussell King
Add irqtrace function calls to the undefined exception handler, so that we get sane lockdep traces from locking problems in undefined exception handlers. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2011-07-02ARM: entry: avoid enabling interrupts in prefetch/data abort handlersRussell King
Avoid enabling interrupts if the parent context had interrupts enabled in the abort handler assembly code, and move this into the breakpoint/ page/alignment fault handlers instead. This gets rid of some special-casing for the breakpoint fault handlers from the low level abort handler path. Acked-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2011-06-30ARM: entry: prefetch abort helper: pass aborted pc in r4 rather than r0Russell King
This avoids unnecessary instructions for CPUs which implement the IFAR (instruction fault address register). Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2011-06-30ARM: entry: rejig register allocation in exception entry handlersRussell King
This allows us to avoid moving registers twice to work around the clobbered registers when we add calls to trace_hardirqs_{on,off}. Ensure that all SVC handlers return with SPSR in r5 for consistency. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2011-06-29ARM: entry: no need to check parent IRQ mask in IRQ handler returnRussell King
There's no point checking to see whether IRQs were masked in the parent context when returning from IRQ handling - the fact that we're handling an IRQ means that the parent context must have had IRQs unmasked. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2011-06-29ARM: entry: no need to increase preempt count for IRQ handlersRussell King
irq_enter() and irq_exit() already take care of the preempt_count handling for interrupts, which increment and decrement the hardirq bits of the preempt count. So we can remove the preempt count handing in our IRQ entry/exit assembly, like x86 did some 9 years ago. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2011-06-29ARM: entry: prefetch/data abort helpers: avoid corrupting r4Russell King
Replace r4 with ip for calling abort helpers - ip is allowed to be corrupted by called functions in the ABI, so it makes more sense to use such a register. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2011-06-29ARM: entry: prefetch/data abort helpers: convert to macrosRussell King
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2011-06-28Merge branch 'cmpxchg64' of git://git.linaro.org/people/nico/linux into ↵Russell King
2011-06-28ARM: add a kuser_cmpxchg64 user space helperNicolas Pitre
Some user space applications are designed around the ability to perform atomic operations on 64 bit values. Since this is natively possible only with ARMv6k and above, let's provide a new kuser helper to perform the operation with kernel supervision on pre ARMv6k hardware. Signed-off-by: Nicolas Pitre <nicolas.pitre@linaro.org> Tested-by: Dave Martin <dave.martin@linaro.org>
2011-06-20ARM: kuser: move interface documentation out of the source codeNicolas Pitre
Digging into some assembly file in order to get information about the kuser helpers is not that convivial. Let's move that information to a better formatted file in Documentation/arm/ and improve on it a bit. Thanks to Dave Martin <dave.martin@linaro.org> for the initial cleanup and clarifications. Signed-off-by: Nicolas Pitre <nicolas.pitre@linaro.org> Acked-by: Dave Martin <dave.martin@linaro.org>
2011-06-06ARM: 6952/1: fix lockdep warning of "unannotated irqs-off"Ming Lei
This patch fixes the lockdep warning of "unannotated irqs-off"[1]. After entering __irq_usr, arm core will disable interrupt automatically, but __irq_usr does not annotate the irq disable, so lockdep may complain the warning if it has chance to check this in irq handler. This patch adds trace_hardirqs_off in __irq_usr before entering irq_handler to handle the irq, also calls ret_to_user_from_irq to avoid calling disable_irq again. This is also a fix for irq off tracer. [1], lockdep warning log of "unannotated irqs-off" [ 13.804687] ------------[ cut here ]------------ [ 13.809570] WARNING: at kernel/lockdep.c:3335 check_flags+0x78/0x1d0() [ 13.816467] Modules linked in: [ 13.819732] Backtrace: [ 13.822357] [<c01cb42c>] (dump_backtrace+0x0/0x100) from [<c06abb14>] (dump_stack+0x20/0x24) [ 13.831268] r6:c07d8c2c r5:00000d07 r4:00000000 r3:00000000 [ 13.837280] [<c06abaf4>] (dump_stack+0x0/0x24) from [<c01ffc04>] (warn_slowpath_common+0x5c/0x74) [ 13.846649] [<c01ffba8>] (warn_slowpath_common+0x0/0x74) from [<c01ffc48>] (warn_slowpath_null+0x2c/0x34) [ 13.856781] r8:00000000 r7:00000000 r6:c18b8194 r5:60000093 r4:ef182000 [ 13.863708] r3:00000009 [ 13.866485] [<c01ffc1c>] (warn_slowpath_null+0x0/0x34) from [<c0237d84>] (check_flags+0x78/0x1d0) [ 13.875823] [<c0237d0c>] (check_flags+0x0/0x1d0) from [<c023afc8>] (lock_acquire+0x4c/0x150) [ 13.884704] [<c023af7c>] (lock_acquire+0x0/0x150) from [<c06af638>] (_raw_spin_lock+0x4c/0x84) [ 13.893798] [<c06af5ec>] (_raw_spin_lock+0x0/0x84) from [<c01f9a44>] (sched_ttwu_pending+0x58/0x8c) [ 13.903320] r6:ef92d040 r5:00000003 r4:c18b8180 [ 13.908233] [<c01f99ec>] (sched_ttwu_pending+0x0/0x8c) from [<c01f9a90>] (scheduler_ipi+0x18/0x1c) [ 13.917663] r6:ef183fb0 r5:00000003 r4:00000000 r3:00000001 [ 13.923645] [<c01f9a78>] (scheduler_ipi+0x0/0x1c) from [<c01bc458>] (do_IPI+0x9c/0xfc) [ 13.932006] [<c01bc3bc>] (do_IPI+0x0/0xfc) from [<c06b0888>] (__irq_usr+0x48/0xe0) [ 13.939971] Exception stack(0xef183fb0 to 0xef183ff8) [ 13.945281] 3fa0: ffffffc3 0001500c 00000001 0001500c [ 13.953948] 3fc0: 00000050 400b45f0 400d9000 00000000 00000001 400d9600 6474e552 bea05b3c [ 13.962585] 3fe0: 400d96c0 bea059c0 400b6574 400b65d8 20000010 ffffffff [ 13.969573] r6:00000403 r5:fa240100 r4:ffffffff r3:20000010 [ 13.975585] ---[ end trace efc4896ab0fb62cb ]--- [ 13.980468] possible reason: unannotated irqs-off. [ 13.985534] irq event stamp: 1610 [ 13.989044] hardirqs last enabled at (1610): [<c01c703c>] no_work_pending+0x8/0x2c [ 13.997131] hardirqs last disabled at (1609): [<c01c7024>] ret_slow_syscall+0xc/0x1c [ 14.005371] softirqs last enabled at (0): [<c01fe5e4>] copy_process+0x2cc/0xa24 [ 14.013183] softirqs last disabled at (0): [< (null)>] (null) Signed-off-by: Ming Lei <ming.lei@canonical.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2011-02-12ARM: move cache/processor/fault glue to separate include filesRussell King
This allows the cache/processor/fault glue to be more easily used from assembler code. Tested on Assabet and Tegra 2. Tested-by: Colin Cross <ccross@android.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2011-01-06Merge branch 'devel-stable' into develRussell King
Conflicts: arch/arm/mach-pxa/clock.c arch/arm/mach-pxa/clock.h
2011-01-06Merge branch 'misc' into develRussell King
Conflicts: arch/arm/Kconfig arch/arm/common/Makefile arch/arm/kernel/Makefile arch/arm/kernel/smp.c
2011-01-06Merge branch 'smp' into miscRussell King
Conflicts: arch/arm/kernel/entry-armv.S arch/arm/mm/ioremap.c
2010-12-24ARM: 6538/1: Subarch IRQ handler macros V3Magnus Damm
Per subarch interrupt handler macros V3. This patch breaks out code from the irq_handler macro into arch_irq_handler and arch_irq_handler_default. The macros are put in the header file "entry-macro-multi.S" The arch_irq_handler_default macro is designed to be used by irq_handler in entry-armv.S while arch_irq_handler is suitable for per-subarch use. Signed-off-by: Magnus Damm <damm@opensource.se> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2010-12-24ARM: 6532/1: Allow machine to specify it's own IRQ handlers at run-timeeric miao
Normally different ARM platform has different way to decode the IRQ hardware status and demultiplex to the corresponding IRQ handler. This is highly optimized by macro irq_handler in entry-armv.S, and each machine defines their own macro to decode the IRQ number. However, this prevents multiple machine classes to be built into a single kernel. By allowing each machine to specify thier own handler, and making function pointer 'handle_arch_irq' to point to it at run time, this can be solved. And introduce CONFIG_MULTI_IRQ_HANDLER to allow both solutions to work. Comparing with the highly optimized macro of irq_handler, the new function must be written with care not to lose too much performance. And the IPI stuff on SMP is expected to move to the provided arch IRQ handler as well. The assembly code to invoke handle_arch_irq is optimized by Russell King. Signed-off-by: Eric Miao <eric.miao@canonical.com> Acked-by: Nicolas Pitre <nicolas.pitre@linaro.org> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2010-12-22Merge branch 'devel' of ↵Russell King
git://git.kernel.org/pub/scm/linux/kernel/git/ycmiao/pxa-linux-2.6 into devel-stable
2010-12-20ARM: 6516/1: Allow SMP_ON_UP to work with Thumb-2 kernels.Dave Martin
* __fixup_smp_on_up has been modified with support for the THUMB2_KERNEL case. For THUMB2_KERNEL only, fixups are split into halfwords in case of misalignment, since we can't rely on unaligned accesses working before turning the MMU on. No attempt is made to optimise the aligned case, since the number of fixups is typically small, and it seems best to keep the code as simple as possible. * Add a rotate in the fixup_smp code in order to support CPU_BIG_ENDIAN, as suggested by Nicolas Pitre. * Add an assembly-time sanity-check to ALT_UP() to ensure that the content really is the right size (4 bytes). (No check is done for ALT_SMP(). Possibly, this could be fixed by splitting the two uses ot ALT_SMP() (ALT_SMP...SMP_UP versus ALT_SMP...SMP_UP_B) into two macros. In the first case, ALT_SMP needs to expand to >= 4 bytes, not == 4.) * smp_mpidr.h (which implements ALT_SMP()/ALT_UP() manually due to macro limitations) has not been modified: the affected instruction (mov) has no 16-bit encoding, so the correct instruction size is satisfied in this case. * A "mode" parameter has been added to smp_dmb: smp_dmb arm @ assumes 4-byte instructions (for ARM code, e.g. kuser) smp_dmb @ uses W() to ensure 4-byte instructions for ALT_SMP() This avoids assembly failures due to use of W() inside smp_dmb, when assembling pure-ARM code in the vectors page. There might be a better way to achieve this. * Kconfig: make SMP_ON_UP depend on (!THUMB2_KERNEL || !BIG_ENDIAN) i.e., THUMB2_KERNEL is now supported, but only if !BIG_ENDIAN (The fixup code for Thumb-2 currently assumes little-endian order.) Tested using a single generic realview kernel on: ARM RealView PB-A8 (CONFIG_THUMB2_KERNEL={n,y}) ARM RealView PBX-A9 (SMP) Signed-off-by: Dave Martin <dave.martin@linaro.org> Acked-by: Nicolas Pitre <nicolas.pitre@linaro.org> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2010-12-06ARM: hw_breakpoint: disable preemption during debug exception handlingWill Deacon
On ARM, debug exceptions occur in the form of data or prefetch aborts. One difference is that debug exceptions require access to per-cpu banked registers and data structures which are not saved in the low-level exception code. For kernels built with CONFIG_PREEMPT, there is an unlikely scenario that the debug handler ends up running on a different CPU from the one that originally signalled the event, resulting in random data being read from the wrong registers. This patch adds a debug_entry macro to the low-level exception handling code which checks whether the taken exception is a debug exception. If it is, the preempt count for the faulting process is incremented. After the debug handler has finished, the count is decremented. Acked-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2010-12-04ARM: 6519/1: kuser: Fix incorrect cmpxchg syscall in kuser helpersDave Martin
The existing code invokes the syscall with rubbish in r7, due to what looks like an incorrect literal load idiom. Reviewed-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Dave Martin <dave.martin@linaro.org> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2010-12-03ARM: SMP: pass an ipi number to smp_cross_call()Russell King
This allows us to use smp_cross_call() to trigger a number of different software generated interrupts, rather than combining them all on one SGI. Recover the SGI number via do_IPI. Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2010-11-04ARM: 6384/1: Remove the domain switching on ARMv6k/v7 CPUsCatalin Marinas
This patch removes the domain switching functionality via the set_fs and __switch_to functions on cores that have a TLS register. Currently, the ioremap and vmalloc areas share the same level 1 page tables and therefore have the same domain (DOMAIN_KERNEL). When the kernel domain is modified from Client to Manager (via the __set_fs or in the __switch_to function), the XN (eXecute Never) bit is overridden and newer CPUs can speculatively prefetch the ioremap'ed memory. Linux performs the kernel domain switching to allow user-specific functions (copy_to/from_user, get/put_user etc.) to access kernel memory. In order for these functions to work with the kernel domain set to Client, the patch modifies the LDRT/STRT and related instructions to the LDR/STR ones. The user pages access rights are also modified for kernel read-only access rather than read/write so that the copy-on-write mechanism still works. CPU_USE_DOMAINS gets disabled only if the hardware has a TLS register (CPU_32v6K is defined) since writing the TLS value to the high vectors page isn't possible. The user addresses passed to the kernel are checked by the access_ok() function so that they do not point to the kernel space. Tested-by: Anton Vorontsov <cbouatmailru@gmail.com> Cc: Tony Lindgren <tony@atomide.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2010-10-04ARM: Allow SMP kernels to boot on UP systemsRussell King
UP systems do not implement all the instructions that SMP systems have, so in order to boot a SMP kernel on a UP system, we need to rewrite parts of the kernel. Do this using an 'alternatives' scheme, where the kernel code and data is modified prior to initialization to replace the SMP instructions, thereby rendering the problematical code ineffectual. We use the linker to generate a list of 32-bit word locations and their replacement values, and run through these replacements when we detect a UP system. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2010-07-31Merge branch 'devel-stable' into develRussell King
Conflicts: arch/arm/kernel/entry-armv.S arch/arm/kernel/setup.c arch/arm/mm/init.c
2010-07-31Merge branches 'at91', 'ep93xx', 'kexec', 'iop', 'lmb', 'nomadik', 'nuc', ↵Russell King
'pl', 'spear' and 'versatile' into devel
2010-07-21Merge git://git.kernel.org/pub/scm/linux/kernel/git/nico/orion into devel-stableRussell King