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2009-12-18ARM: Convert VFP/Crunch/XscaleCP thread_release() to exit_thread()Russell King
This avoids races in the VFP code where the dead thread may have state on another CPU. By moving this code to exit_thread(), we will be running as the thread, and therefore be running on the current CPU. This means that we can ensure that the only local state is accessed in the thread notifiers. Acked-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2009-12-13ARM: VFP: fix vfp thread init bug and document vfp notifier entry conditionsRussell King
When the VFP notifier is called for flush_thread(), we may be preemptible, meaning we might migrate to another CPU, which means referencing the current CPU number without some form of locking is invalid, and can cause data corruption. For the most cases, this isn't a problem since atomic notifiers are run under rcu lock, which for most configurations results in preemption being disabled - except when the preemptable tree-based rcu implementation is selected. Let's make it safe anyway. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2009-07-24Thumb-2: Implement the unified VFP supportCatalin Marinas
This patch modifies the VFP files for the ARM/Thumb-2 unified assembly syntax. Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2009-07-24Thumb-2: Add some .align statements to the .S filesCatalin Marinas
Since the Thumb-2 instructions can be 16-bit wide, data in the .text sections may not be aligned to a 32-bit word and this leads to unaligned exceptions. This patch does not affect the ARM code generation. Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2009-05-30Fix the VFP handling on the Feroceon CPUCatalin Marinas
This CPU generates synchronous VFP exceptions in a non-standard way - the FPEXC.EX bit set but without the FPSCR.IXE bit being set like in the VFP subarchitecture 1 or just the FPEXC.DEX bit like in VFP subarchitecture 2. The main problem is that the faulty instruction (which needs to be emulated in software) will be restarted several times (normally until a context switch disables the VFP). This patch ensures that the VFP exception is treated as synchronous. Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Cc: Nicolas Pitre <nico@cam.org>
2009-04-01[ARM] 5440/1: Fix VFP state corruption due to preemption during VFP exceptionsGeorge G. Davis
We've observed that ARM VFP state can be corrupted during VFP exception handling when PREEMPT is enabled. The exact conditions are difficult to reproduce but appear to occur during VFP exception handling when a task causes a VFP exception which is handled via VFP_bounce and is then preempted by yet another task which in turn causes yet another VFP exception. Since the VFP_bounce code is not preempt safe, VFP state then becomes corrupt. In order to prevent preemption from occuring while handling a VFP exception, this patch disables preemption while handling VFP exceptions. Signed-off-by: George G. Davis <gdavis@mvista.com> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2009-02-12[ARM] 5388/1: Add hwcap bits for VFPv3 and VFPv3D16Catalin Marinas
The VFPv3D16 is a VFPv3 CPU configuration where only 16 double registers are present, as the VFPv2 configuration. This patch adds the corresponding hwcap bits so that applications or debuggers have more information about the supported features. Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2009-02-12[ARM] 5387/1: Add ptrace VFP support on ARMCatalin Marinas
This patch adds ptrace support for setting and getting the VFP registers using PTRACE_SETVFPREGS and PTRACE_GETVFPREGS. The user_vfp structure defined in asm/user.h contains 32 double registers (to cover VFPv3 and Neon hardware) and the FPSCR register. Cc: Paul Brook <paul@codesourcery.com> Cc: Daniel Jacobowitz <dan@codesourcery.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2008-12-18[ARM] 5349/1: VFP: Add PM code to save and restore current VFP stateBen Dooks
When CONFIG_PM is selected, the VFP code does not have any handler installed to deal with either saving the VFP state of the current task, nor does it do anything to try and restore the VFP after a resume. On resume, the VFP will have been reset and the co-processor access control registers are in an indeterminate state (very probably the CP10 and CP11 the VFP uses will have been disabled by the ARM core reset). When this happens, resume will break as soon as it tries to unfreeze the tasks and restart scheduling. Add a sys device to allow us to hook the suspend call to save the current thread state if the thread is using VFP and a resume hook which restores the CP10/CP11 access and ensures the VFP is disabled so that the lazy swapping will take place on next access. Signed-off-by: Ben Dooks <ben-linux@fluff.org> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2008-11-06ARMv7: Branch over conditional undefined instructions in vfphw.SCatalin Marinas
On ARMv7, conditional undefined instructions may generate exceptions even if the condition is not met. The vfphw.S contains the FPINST and FPINST2 access instructions which may not be present on processors with synchronous VFP exceptions. Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2008-11-06Add HWCAP_NEON to the ARM hwcap.h fileCatalin Marinas
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2008-09-01[ARM] 5227/1: Add the ENDPROC declarations to the .S filesCatalin Marinas
This declaration specifies the "function" type and size for various assembly functions, mainly needed for generating the correct branch instructions in Thumb-2. Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2008-06-26smp_call_function: get rid of the unused nonatomic/retry argumentJens Axboe
It's never used and the comments refer to nonatomic and retry interchangably. So get rid of it. Acked-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2008-01-26[ARM] 4583/1: ARMv7: Add VFPv3 supportCatalin Marinas
This patch adds the support for VFPv3 (the kernel currently supports VFPv2). The main difference is 32 double registers (compared to 16). Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2008-01-26[ARM] 4582/2: Add support for the common VFP subarchitectureCatalin Marinas
This patch allows the VFP support code to run correctly on CPUs compatible with the common VFP subarchitecture specification (Appendix B in the ARM ARM v7-A and v7-R edition). It implements support for VFP subarchitecture 2 while being backwards compatible with subarchitecture 1. On VFP subarchitecture 1, the arithmetic exceptions are asynchronous (or imprecise as described in the old ARM ARM) unless the FPSCR.IXE bit is 1. The exceptional instructions can be read from FPINST and FPINST2 registers. With VFP subarchitecture 2, the arithmetic exceptions can also be synchronous and marked by the FPEXC.DEX bit (the FPEXC.EX bit is cleared). CPUs implementing the synchronous arithmetic exceptions don't have the FPINST and FPINST2 registers and accessing them would trigger and undefined exception. Note that FPEXC.EX bit has an additional meaning on subarchitecture 1 - if it isn't set, there is no additional information in FPINST and FPINST2 that needs to be saved at context switch or when lazy-loading the VFP state of a different thread. The patch also removes the clearing of the cumulative exception flags in FPSCR when additional exceptions were raised. It is up to the user application to clear these bits. Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2008-01-10[ARM] vfp: fix fuitod/fsitod instructionsRussell King
These two instructions exceptionally take a single precision register as their operand. This means we can't use vfp_get_dm() to read the register number - we need to use vfp_get_sm() instead. Add a flag to indicate this exception to the general rule. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2007-10-20[ARM] 4630/1: Fix the vector stride of the double vector instruction.Takashi Ohmasa
The vector stride of the double-precision vector instructions must be changed to 1-2 from even 2-4, because the double registers numbering has been changed to 0-15 from even 0-30 by 1356c1948da967bc1d4c663762bfe21dfcec4b2f commit. Signed-off-by: Takashi Ohmasa <ohmasa.takashi@jp.panasonic.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2007-10-20[ARM] 4629/1: Fix VFP emulation code to clear all exception flags of FPEXCTakashi Ohmasa
All exception flags of the FPEXC register must be cleared before returning from exception code to user code, including FP2V and OFC. Signed-off-by: Takashi Ohmasa <ohmasa.takashi@jp.panasonic.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2007-10-15kbuild: enable 'make AFLAGS=...' to add additional options to ASSam Ravnborg
The variable AFLAGS is a wellknown variable and the usage by kbuild may result in unexpected behaviour. On top of that several people over time has asked for a way to pass in additional flags to gcc. This patch replace use of AFLAGS with KBUILD_AFLAGS all over the tree. Patch was tested on following architectures: alpha, arm, i386, x86_64, mips, sparc, sparc64, ia64, m68k, s390 Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
2007-09-13[ARM] 4567/1: Fix 'Oops - undefined instruction' when CONFIG_VFP=y on non ↵Tzachi Perelstein
VFP device vfp_init() takes care of the condition when CONFIG_VFP=y but no real VFP device exists. However, when this condition is true, a compiler might misplace code lines in a way that will break this support. (To be more specific - fmrx(FPSID) might be executed before vfp_testing_entry assignment, which will end up with Oops - undefined instruction). This patch adds a barrier() to guarantee the right execution ordering. Signed-off-by: Assaf Hoffman Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2007-07-20[ARM] vfp: make fpexc bit names less verboseRussell King
Use the fpexc abbreviated names instead of long verbose names for fpexc bits. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2007-06-10[ARM] VFP: fix section mismatch errorRussell King
Fix a real section mismatch issue; the test code is thrown away after initialisation, but if we do not detect the VFP hardware, it is left hooked into the exception handler. Any VFP instructions which are subsequently executed risk calling the discarded exception handler. Introduce a new "null" handler which returns to the "unrecognised fault" return address. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2007-04-22[ARM] Remove unnecessary asm/ptrace.h from VFP support codeRussell King
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2007-01-25[ARM] 4111/1: Allow VFP to work with thread migration on SMPCatalin Marinas
The current lazy saving of the VFP registers is no longer possible with thread migration on SMP. This patch implements a per-CPU vfp-state pointer and the saving of the VFP registers at every context switch. The registers restoring is still performed in a lazy way. Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2007-01-02[ARM] Fix VFP initialisation issue for SMP systemsRussell King
When we install the handlers for context switching, we must enable VFP on all CPU cores, otherwise undefined (and random) effects occur. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2006-12-08[ARM] Handle HWCAP_VFP in VFP support codeRussell King
Don't set HWCAP_VFP in the processor support file; not only does it depend on the processor features, but it also depends on the support code being present. Therefore, only set it if the support code detects that we have a VFP coprocessor attached. Also, move the VFP handling of the coprocessor access register into the VFP support code. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2006-10-28[ARM] 3900/1: Fix VFP Division by Zero exception handling.Takashi Ohmasa
The SIGFPE signal should be generated if Division by Zero exception is detected. Signed-off-by: Takashi Ohmasa <ohmasa.takashi@jp.panasonic.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2006-10-28[ARM] 3899/1: Fix the normalization of the denormal double precision number.Takashi Ohmasa
The significand should be shifted until the value of bit [62] is 1 to normalize the denormal double number. Signed-off-by: Takashi Ohmasa <ohmasa.takashi@jp.panasonic.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2006-10-11[PATCH] arm __user annotationsAl Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-10-03[PATCH] arm build fail: vfpsingle.cFrederik Deweerdt
It looks like Zach Brown's patch pr_debug-check-pr_debug-arguments worked as inteded. That is, it doesn't "allow completely incorrect code to build." :). The arm build fails with the following message: CC arch/arm/vfp/vfpsingle.o arch/arm/vfp/vfpsingle.c: In function `__vfp_single_normaliseround': arch/arm/vfp/vfpsingle.c:201: error: `func' undeclared (first use in this function) arch/arm/vfp/vfpsingle.c:201: error: (Each undeclared identifier is reported only once arch/arm/vfp/vfpsingle.c:201: error: for each function it appears in.) make[1]: *** [arch/arm/vfp/vfpsingle.o] Error 1 make: *** [arch/arm/vfp] Error 2 The following patch fixes the issue by using func only when DEBUG is defined. Signed-off-by: Frederik Deweerdt <frederik.deweerdt@gmail.com> Cc: Russell King <rmk@arm.linux.org.uk> Cc: Zach Brown <zach.brown@oracle.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-09-25[ARM] Cleanups for 4cc9bd2eaa1063c68341c1c00e66660adcfdf254Russell King
- Document the meaning for OP_SCALAR, OP_SD and add OP_DD. - Formatting cleanups - Remove now redundant code for making compare instructions operate on scalar values. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2006-09-25[ARM] 3789/4: Fix VFP emulation to ignore VECITR for scalar instructionGen FUKATSU
VECITR in Floating-Point Exception register indicates the number of remaining short vector iterations after a potential exception was detected. In case of exception caused by scalar instructions, VECITR is NOT updated. Therefore emulation for VFP must ignore VECITR field and treat "veclen" as zero when recognizing scalar instructing. Signed-off-by: Gen Fukatsu <fukatsu.gen@jp.panasonic.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2006-09-20[ARM] 3759/2: Remove uses of %?Daniel Jacobowitz
Patch from Daniel Jacobowitz The ARM kernel has several uses of asm("foo%?"). %? is a GCC internal modifier used to output conditional execution predicates. However, no version of GCC supports conditionalizing asm statements. GCC 4.2 will correctly expand %? to the empty string in user asms. Earlier versions may reuse the condition from the previous instruction. In 'if (foo) asm ("bar%?");' this is somewhat likely to be right... but not reliable. So, the only safe thing to do is to remove the uses of %?. I believe the tlbflush.h occurances were supposed to be removed before, based on the comment about %? not working at the top of that file. Old versions of GCC could omit branches around user asms if the asm didn't mark the condition codes as clobbered. This problem hasn't been seen on any recent (3.x or 4.x) GCC, but it could theoretically happen. So, where %? was removed a cc clobber was added. Signed-off-by: Daniel Jacobowitz <dan@codesourcery.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2006-09-20[ARM] Optimise VFP thread notify function a littleRussell King
The common case for the thread notifier is a context switch. Tell gcc that this is the most likely condition so it can optimise the function for this case. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2006-08-30[ARM] 3750/3: Fix double VFP emulation for EABI kernelsDaniel Jacobowitz
Patch from Daniel Jacobowitz vfp_put_double didn't work in a CONFIG_AEABI kernel. By swapping the arguments, we arrange for them to be in the same place regardless of ABI. I made the same change to vfp_put_float for consistency. Signed-off-by: Daniel Jacobowitz <dan@codesourcery.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2006-08-27[ARM] 3758/1: Preserve signalling NaNs in conversionDaniel Jacobowitz
Patch from Daniel Jacobowitz The fcvtds and fcvtsd instructions were generating a qnan bit pattern for both quiet and signalling NaNs. Signed-off-by: Daniel Jacobowitz <dan@codesourcery.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2006-08-27[ARM] 3749/3: Correct VFP single/double conversion emulationDaniel Jacobowitz
Patch from Daniel Jacobowitz The fcvtsd/fcvtds emulation was left behind when the numbering of double precision registers was changed from 0-30 to 0-15. Both conversion instructions were writing their results to the wrong register. Also, the conversion instructions should stop after the first element even if a vector length is specified. Signed-off-by: Daniel Jacobowitz <dan@codesourcery.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2006-08-27[ARM] 3748/3: Correct error check in vfp_raise_exceptionsDaniel Jacobowitz
Patch from Daniel Jacobowitz The recent fix to hide VFP_NAN_FLAG broke the check in vfp_raise_exceptions; it would attempt to deliver an exception mask of 0xfffffeff instead of reporting a serious error condition using printk. Define a safe constant to use for an invalid exception maskm, and use it at both ends. Signed-off-by: Daniel Jacobowitz <dan@codesourcery.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2006-06-30Remove obsolete #include <linux/config.h>Jörn Engel
Signed-off-by: Jörn Engel <joern@wohnheim.fh-wedel.de> Signed-off-by: Adrian Bunk <bunk@stusta.de>
2006-06-22[ARM] Enable VFP to be built when non-VFP capable CPUs are selectedRussell King
Since we pass flags to the compiler to control code generation based on the least capable selected CPU, if we want to include VFP support, we must tweak the assembler flags to allow the VFP instructions. Moreover, we must not use the mrrc/mcrr versions since these will not be recognised by the assembler. We do not convert all instructions to the VFP-equivalent (yet) since binutils appears to barf on "fmrx rn, fpinst" and doesn't provide any other way (other than using the mrc equivalent) to encode this instruction - which is rather a problem when you have a VFP implementation which requires these instructions. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2006-06-22[ARM] Add thread_notify infrastructureRussell King
Some machine classes need to allow VFP support to be built into the kernel, but still allow the kernel to run even though VFP isn't present. Unfortunately, the kernel hard-codes VFP instructions into the thread switch, which prevents this being run-time selectable. Solve this by introducing a notifier which things such as VFP can hook into to be informed of events which affect the VFP subsystem (eg, creation and destruction of threads, switches between threads.) Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2006-05-05[ARM] 3499/1: Fix VFP FPSCR corruption for double exception caseGeorge G. Davis
Patch from George G. Davis The ARM VFP FPSCR register is corrupted when a condition flags modifying VFP instruction is followed by a non-condition flags modifying VFP instruction and both instructions raise exceptions. The fix is to read the current FPSCR in between emulation of these two instructions and use the current FPSCR value when handling the second exception. Signed-off-by: George G. Davis <gdavis@mvista.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2006-04-25[ARM] vfp: fix leak of VFP_NAN_FLAG into FPSCRRussell King
The VFP code can leak VFP_NAN_FLAG into the FPSCR. It doesn't correspond to any real FPSCR bit (and overlaps one of the exception flags). Bug report from Daniel Jacobowitz Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2006-04-10[ARM] 3473/1: Use numbers 0-15 for the VFP double registersCatalin Marinas
Patch from Catalin Marinas This patch changes the double registers numbering to 0-15 from even 0-30, in preparation for future VFP extensions. It also fixes the VFP_REG_ZERO bug (value 16 actually represents the 8th double register with the original numbering). The original mcrr/mrrc on CP10 were generating FMRRS/FMSRR instead of FMRRD/FMDRR. The patch changes to CP11 for the correct instructions. Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2006-04-10[ARM] 3471/1: FTOSI functions should return 0 for NaNCatalin Marinas
Patch from Catalin Marinas The NaN case was dealed with by the "exponent >= ... + 32" condition but it was not setting the value "d" to 0. Signed-off-by: Ken'ichi Kuromusha <musha@aplix.co.jp> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2006-03-25[ARM] 3398/1: Fix the VFP registers loading/storing base addressCatalin Marinas
Patch from Catalin Marinas The current VFP code corrupts the VFP registers (including the control ones) if more than one floating point application is executed at the same time. This patch fixes the updating of the load/store base addresses for the VFP registers. Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2006-03-23[ARM] Move enable_irq and disable_irq to assembler.hRussell King
5d25ac038a317d454a4321cba955f756400835a5 broke VFP builds due to enable_irq not being defined as an assembly macro. Move it to assembler.h so everyone can use it. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2006-03-21[ARM] Move IRQ enable after coprocessor number decodeRussell King
Allow the individual coprocessor handlers to decide when to enable interrupts, rather than unconditionally enabling them. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2005-09-09kbuild: arm - use generic asm-offsets.h supportSam Ravnborg
Delete obsoleted stuff from arch Makefile and rename constants.h to asm-offsets.h Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
2005-08-03[PATCH] ARM: 2841/1: Fix VFP +/-0 case for doubles additionCatalin Marinas
Patch from Catalin Marinas The IEEE 754 standard specifies that the result of (x - x), where x is a valid number, should be -0 if the rounding mode is towards minus infinity or +0 otherwise. Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>