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* MIPS: Simplify FP context initializationPaul Burton2018-11-091-144/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | MIPS has up until now had 3 different ways for a task's floating point context to be initialized: - If the task's first use of FP involves it gaining ownership of an FPU then _init_fpu() is used to initialize the FPU's registers such that they all contain ~0, and the FPU registers will be stored to struct thread_info later (eg. when context switching). - If the task first uses FP on a CPU without an associated FPU then fpu_emulator_init_fpu() initializes the task's floating point register state in struct thread_info such that all floating point register contain the bit pattern 0x7ff800007ff80000, different to the _init_fpu() behaviour. - If a task's floating point context is first accessed via ptrace then init_fp_ctx() initializes the floating point register state in struct thread_info to ~0, giving equivalent state to _init_fpu(). The _init_fpu() path has 2 separate implementations - one for r2k/r3k style systems & one for r4k style systems. The _init_fpu() path also requires that we be careful to clear & restore the value of the Config5.FRE bit on modern systems in order to avoid inadvertently triggering floating point exceptions. None of this code is in a performance critical hot path - it runs only the first time a task uses floating point. As such it doesn't seem to warrant the complications of maintaining the _init_fpu() path. Remove _init_fpu() & fpu_emulator_init_fpu(), instead using init_fp_ctx() consistently to initialize floating point register state in struct thread_info. Upon a task's first use of floating point this will typically mean that we initialize state in memory & then load it into FPU registers using _restore_fp() just as we would on a context switch. For other paths such as __compute_return_epc_for_insn() or mipsr2_decoder() this results in a significant simplification of the work to be done. Signed-off-by: Paul Burton <paul.burton@mips.com> Patchwork: https://patchwork.linux-mips.org/patch/21002/ Cc: linux-mips@linux-mips.org
* MIPS: Fix MIPS64 FP save/restore on 32-bit kernelsJames Hogan2017-11-091-10/+10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 32-bit kernels can be configured to support MIPS64, in which case neither CONFIG_64BIT or CONFIG_CPU_MIPS32_R* will be set. This causes the CP0_Status.FR checks at the point of floating point register save and restore to be compiled out, which results in odd FP registers not being saved or restored to the task or signal context even when CP0_Status.FR is set. Fix the ifdefs to use CONFIG_CPU_MIPSR2 and CONFIG_CPU_MIPSR6, which are enabled for the relevant revisions of either MIPS32 or MIPS64, along with some other CPUs such as Octeon (r2), Loongson1 (r2), XLP (r2), Loongson 3A R2. The suspect code originates from commit 597ce1723e0f ("MIPS: Support for 64-bit FP with O32 binaries") in v3.14, however the code in __enable_fpu() was consistent and refused to set FR=1, falling back to software FPU emulation. This was suboptimal but should be functionally correct. Commit fcc53b5f6c38 ("MIPS: fpu.h: Allow 64-bit FPU on a 64-bit MIPS R6 CPU") in v4.2 (and stable tagged back to 4.0) later introduced the bug by updating __enable_fpu() to set FR=1 but failing to update the other similar ifdefs to enable FR=1 state handling. Fixes: fcc53b5f6c38 ("MIPS: fpu.h: Allow 64-bit FPU on a 64-bit MIPS R6 CPU") Signed-off-by: James Hogan <jhogan@kernel.org> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Paul Burton <paul.burton@imgtec.com> Cc: linux-mips@linux-mips.org Cc: <stable@vger.kernel.org> # 4.0+ Patchwork: https://patchwork.linux-mips.org/patch/16739/
* MIPS: Move r4k FP code from r4k_switch.S to r4k_fpu.SPaul Burton2017-08-291-0/+196
| | | | | | | | | | | | | | | | | | | | Move _save_fp(), _restore_fp(), _save_msa(), _restore_msa(), _init_msa_upper() & _init_fpu() out of r4k_switch.S & into r4k_fpu.S. This allows us to clean up the way in which Octeon includes the default r4k implementations of these FP functions despite replacing resume(), and makes CONFIG_R4K_FPU more straightforwardly represent all configurations that have an R4K-style FPU, including Octeon. Besides cleaning up this will be useful for later patches which disable FP support. [ralf@linux-mips.org: Fixed build issues reported by Arnd Bergmann <arnd@arndb.de>] Signed-off-by: Paul Burton <paul.burton@imgtec.com> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/16237/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
* MIPS: Use copy_s.fmt rather than copy_u.fmtPaul Burton2016-05-091-5/+5
| | | | | | | | | | | | | | | | | | | | In revision 1.12 of the MSA specification, the copy_u.w instruction has been removed for MIPS32 & the copy_u.d instruction has been removed for MIPS64. Newer toolchains (eg. Codescape SDK essentials 2015.10) will complain about this like so: arch/mips/kernel/r4k_fpu.S:290: Error: opcode not supported on this processor: mips32r2 (mips32r2) `copy_u.w $1,$w26[3]' Since we always copy to the width of a GPR, simply use copy_s instead of copy_u to fix this. Signed-off-by: Paul Burton <paul.burton@imgtec.com> Signed-off-by: James Hogan <james.hogan@imgtec.com> Cc: linux-mips@linux-mips.org Cc: <stable@vger.kernel.org> # 4.3.x+ Patchwork: https://patchwork.linux-mips.org/patch/13061/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
* MIPS: Avoid variant of .type unsupported by LLVM AssemblerDaniel Sanders2016-02-291-1/+1
| | | | | | | | | | | | | | | | | | | | The target independent parts of the LLVM Lexer considers 'fault@function' to be a single token representing the 'fault' symbol with a 'function' modifier. However, this is not the case in the .type directive where 'function' refers to STT_FUNC from the ELF standard. Although GAS accepts it, '.type symbol@function' is an undocumented form of this directive. The documentation specifies a comma between the symbol and '@function'. Signed-off-by: Scott Egerton <Scott.Egerton@imgtec.com> Signed-off-by: Daniel Sanders <daniel.sanders@imgtec.com> Reviewed-by: Maciej W. Rozycki <macro@imgtec.com> Cc: Paul Burton <paul.burton@imgtec.com> Cc: Leonid Yegoshin <Leonid.Yegoshin@imgtec.com> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/12587/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
* MIPS: Save MSA extended context around signalsPaul Burton2015-09-031-0/+118
| | | | | | | | | | | | | | | | | | | | | | | | | | | It is desirable for signal handlers to be allowed to make use of MSA, particularly if auto vectorisation is used when compiling a program. The MSA context must therefore be saved & restored before & after invoking the signal handler. Make use of the extended context structs defined in the preceding patch to save MSA context after the sigframe when appropriate. [ralf@linux-mips.org: Fixed conflicts.] Signed-off-by: Paul Burton <paul.burton@imgtec.com> Cc: linux-mips@linux-mips.org Cc: Guenter Roeck <linux@roeck-us.net> Cc: Matthew Fortune <matthew.fortune@imgtec.com> Cc: Leonid Yegoshin <Leonid.Yegoshin@imgtec.com> Cc: linux-kernel@vger.kernel.org Cc: Richard Weinberger <richard@nod.at> Cc: James Hogan <james.hogan@imgtec.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Markos Chandras <markos.chandras@imgtec.com> Cc: Manuel Lauss <manuel.lauss@gmail.com> Cc: Maciej W. Rozycki <macro@codesourcery.com> Patchwork: https://patchwork.linux-mips.org/patch/10796/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
* MIPS: Use common FP sigcontext code for O32 compatPaul Burton2015-09-031-114/+0
| | | | | | | | | | | | | | | | | | | | | | | | | Make use of the common FP sigcontext code for O32 binaries running on MIPS64 kernels now that it is taking appropriate offsets into struct sigcontext(32) from struct mips_abi. [ralf@linux-mips.org: Fixed reject.] Signed-off-by: Paul Burton <paul.burton@imgtec.com> Cc: linux-mips@linux-mips.org Cc: Guenter Roeck <linux@roeck-us.net> Cc: Matthew Fortune <matthew.fortune@imgtec.com> Cc: Leonid Yegoshin <Leonid.Yegoshin@imgtec.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: linux-kernel@vger.kernel.org Cc: Richard Weinberger <richard@nod.at> Cc: James Hogan <james.hogan@imgtec.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Markos Chandras <markos.chandras@imgtec.com> Cc: Manuel Lauss <manuel.lauss@gmail.com> Cc: Maciej W. Rozycki <macro@codesourcery.com> Patchwork: https://patchwork.linux-mips.org/patch/10792/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
* MIPS: Use struct mips_abi offsets to save FP contextPaul Burton2015-09-031-70/+81
| | | | | | | | | | | | | | | | | | | | | | | | When saving FP state to struct sigcontext, make use of the offsets provided by struct mips_abi to obtain appropriate addresses for the sc_fpregs & sc_fpc_csr fields of the sigcontext. This is done only for the native struct sigcontext in this patch (ie. for O32 in CONFIG_32BIT kernels or for N64 in CONFIG_64BIT kernels) but is done in preparation for sharing this code with compat ABIs in further patches. Signed-off-by: Paul Burton <paul.burton@imgtec.com> Cc: linux-mips@linux-mips.org Cc: Guenter Roeck <linux@roeck-us.net> Cc: Matthew Fortune <matthew.fortune@imgtec.com> Cc: Leonid Yegoshin <Leonid.Yegoshin@imgtec.com> Cc: linux-kernel@vger.kernel.org Cc: Richard Weinberger <richard@nod.at> Cc: James Hogan <james.hogan@imgtec.com> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Markos Chandras <markos.chandras@imgtec.com> Cc: Manuel Lauss <manuel.lauss@gmail.com> Cc: Maciej W. Rozycki <macro@codesourcery.com> Patchwork: https://patchwork.linux-mips.org/patch/10789/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
* MIPS: Introduce accessors for MSA vector registersPaul Burton2015-09-031-0/+67
| | | | | | | | | | | | | | | | | | Introduce accessor functions allowing the kernel to access arbitrary vector registers using an arbitrary data format. The accessors are implemented in assembly, using macros to avoid massive duplication, in order to make use of the existing support for MSA with & without toolchain support. The accessors will be used in a later patch. Signed-off-by: Paul Burton <paul.burton@imgtec.com> Cc: linux-mips@linux-mips.org Cc: Leonid Yegoshin <Leonid.Yegoshin@imgtec.com> Cc: linux-kernel@vger.kernel.org Cc: James Hogan <james.hogan@imgtec.com> Cc: Markos Chandras <markos.chandras@imgtec.com> Cc: Manuel Lauss <manuel.lauss@gmail.com> Patchwork: https://patchwork.linux-mips.org/patch/10572/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
* MIPS: Push .set mips64r* into the functions needing itPaul Burton2015-03-271-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | The {save,restore}_fp_context{,32} functions require that the assembler allows the use of sdc instructions on any FP register, and this is acomplished by setting the arch to mips64r2 or mips64r6 (using MIPS_ISA_ARCH_LEVEL_RAW). However this has the effect of enabling the assembler to use mips64 instructions in the expansion of pseudo-instructions. This was done in the (now-reverted) commit eec43a224cf1 "MIPS: Save/restore MSA context around signals" which led to my mistakenly believing that there was an assembler bug, when in reality the assembler was just emitting mips64 instructions. Avoid the issue for future commits which will add code to r4k_fpu.S by pushing the .set MIPS_ISA_ARCH_LEVEL_RAW directives into the functions that require it, and remove the spurious assertion declaring the assembler bug. Signed-off-by: Paul Burton <paul.burton@imgtec.com> [james.hogan@imgtec.com: Rebase on v4.0-rc1 and reword commit message to reflect use of MIPS_ISA_ARCH_LEVEL_RAW] Signed-off-by: James Hogan <james.hogan@imgtec.com> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/9612/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
* MIPS: kernel: r4k_fpu: Add support for MIPS R6Leonid Yegoshin2015-02-171-3/+9
| | | | | | | | | Add the MIPS R6 related preprocessor definitions for FPU signal related functions. MIPS R6 only has FR=1 so avoid checking that bit on the C0/Status register. Signed-off-by: Leonid Yegoshin <Leonid.Yegoshin@imgtec.com> Signed-off-by: Markos Chandras <markos.chandras@imgtec.com>
* MIPS: Fix build with binutils 2.24.51+Manuel Lauss2014-11-071-2/+25
| | | | | | | | | | | | | | | | | | | | | | | | | Starting with version 2.24.51.20140728 MIPS binutils complain loudly about mixing soft-float and hard-float object files, leading to this build failure since GCC is invoked with "-msoft-float" on MIPS: {standard input}: Warning: .gnu_attribute 4,3 requires `softfloat' LD arch/mips/alchemy/common/built-in.o mipsel-softfloat-linux-gnu-ld: Warning: arch/mips/alchemy/common/built-in.o uses -msoft-float (set by arch/mips/alchemy/common/prom.o), arch/mips/alchemy/common/sleeper.o uses -mhard-float To fix this, we detect if GAS is new enough to support "-msoft-float" command option, and if it does, we can let GCC pass it to GAS; but then we also need to sprinkle the files which make use of floating point registers with the necessary ".set hardfloat" directives. Signed-off-by: Manuel Lauss <manuel.lauss@gmail.com> Cc: Linux-MIPS <linux-mips@linux-mips.org> Cc: Matthew Fortune <Matthew.Fortune@imgtec.com> Cc: Markos Chandras <Markos.Chandras@imgtec.com> Cc: Maciej W. Rozycki <macro@linux-mips.org> Patchwork: https://patchwork.linux-mips.org/patch/8355/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
* Revert "MIPS: Save/restore MSA context around signals"Paul Burton2014-06-261-213/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This reverts commit eec43a224cf1 "MIPS: Save/restore MSA context around signals" and the MSA parts of ca750649e08c "MIPS: kernel: signal: Prevent save/restore FPU context in user memory" (the restore path of which appears incorrect anyway...). The reverted patch took care not to break compatibility with userland users of struct sigcontext, but inadvertantly changed the offset of the uc_sigmask field of struct ucontext. Thus Linux v3.15 breaks the userland ABI. The MSA context will need to be saved via some other opt-in mechanism, but for now revert the change to reduce the fallout. This will have minimal impact upon use of MSA since the only supported CPU which includes it (the P5600) is 32-bit and therefore requires that the experimental CONFIG_MIPS_O32_FP64_SUPPORT Kconfig option be selected before the kernel will set FR=1 for a task, a requirement for MSA use. Thus the users of MSA are limited to known small groups of people & this patch won't be breaking any previously working MSA-using userland outside of experimental settings. [ralf@linux-mips.org: Fixed rejects.] Cc: stable@vger.kernel.org Reported-by: Joseph S. Myers <joseph@codesourcery.com> Signed-off-by: Paul Burton <paul.burton@imgtec.com> Cc: linux-mips@linux-mips.org Cc: stable@vger.kernel.org Patchwork: https://patchwork.linux-mips.org/patch/7107/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
* Merge branch '3.14-fixes' into mips-for-linux-nextRalf Baechle2014-03-311-8/+8
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| * MIPS: FPU: Fix conflict of register usageHuacai Chen2014-03-141-4/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In _restore_fp_context/_restore_fp_context32, t0 is used for both CP0_Status and CP1_FCSR. This is a mistake and cause FP exeception on boot, so fix it. Signed-off-by: Huacai Chen <chenhc@lemote.com> Tested-by: Aaro Koskinen <aaro.koskinen@iki.fi> Tested-by: Andreas Barth <aba@ayous.org> Cc: John Crispin <john@phrozen.org> Cc: Steven J. Hill <Steven.Hill@imgtec.com> Cc: Aurelien Jarno <aurelien@aurel32.net> Cc: linux-mips@linux-mips.org Cc: Fuxin Zhang <zhangfx@lemote.com> Cc: Zhangjin Wu <wuzhangjin@gmail.com> Patchwork: https://patchwork.linux-mips.org/patch/6507/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
| * MIPS: Replace CONFIG_MIPS64 and CONFIG_MIPS32_R2Paul Bolle2014-03-141-4/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | Commit 597ce1723e0f ("MIPS: Support for 64-bit FP with O32 binaries") introduced references to two undefined Kconfig macros. CONFIG_MIPS32_R2 should clearly be replaced with CONFIG_CPU_MIPS32_R2. And CONFIG_MIPS64 should be replaced with CONFIG_64BIT. Signed-off-by: Paul Bolle <pebolle@tiscali.nl> Cc: linux-mips@linux-mips.org Cc: linux-kernel@vger.kernel.org Patchwork: https://patchwork.linux-mips.org/patch/6522/ Tested-by: Aaro Koskinen <aaro.koskinen@iki.fi> Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
* | MIPS: Fix gigaton of warning building with microMIPS.Ralf Baechle2014-03-311-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | With binutils 2.24 the attempt to switch with microMIPS mode to MIPS III mode through .set mips3 results in *lots* of warnings like {standard input}: Assembler messages: {standard input}:397: Warning: the 64-bit MIPS architecture does not support the `smartmips' extension during a kernel build. Fixed by using .set arch=r4000 instead. This breaks support for building the kernel with binutils 2.13 which was supported for 32 bit kernels only anyway and 2.14 which was a bad vintage for MIPS anyway. Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
* | MIPS: Save/restore MSA context around signalsPaul Burton2014-03-261-0/+213
|/ | | | | | | | | | | | | | | This patch extends sigcontext in order to hold the most significant 64 bits of each vector register in addition to the MSA control & status register. The least significant 64 bits are already saved as the scalar FP context. This makes things a little awkward since the least & most significant 64 bits of each vector register are not contiguous in memory. Thus the copy_u & insert instructions are used to transfer the values of the most significant 64 bits via GP registers. Signed-off-by: Paul Burton <paul.burton@imgtec.com> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/6533/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
* MIPS: Support for 64-bit FP with O32 binariesPaul Burton2014-01-131-4/+70
| | | | | | | | | | | | | | | | | | | | | | | | | | | | CPUs implementing MIPS32 R2 may include a 64-bit FPU, just as MIPS64 CPUs do. In order to preserve backwards compatibility a 64-bit FPU will act like a 32-bit FPU (by accessing doubles from the least significant 32 bits of an even-odd pair of FP registers) when the Status.FR bit is zero, again just like a mips64 CPU. The standard O32 ABI is defined expecting a 32-bit FPU, however recent toolchains support use of a 64-bit FPU from an O32 MIPS32 executable. When an ELF executable is built to use a 64-bit FPU a new flag (EF_MIPS_FP64) is set in the ELF header. With this patch the kernel will check the EF_MIPS_FP64 flag when executing an O32 binary, and set Status.FR accordingly. The addition of O32 64-bit FP support lessens the opportunity for optimisation in the FPU emulator, so a CONFIG_MIPS_O32_FP64_SUPPORT Kconfig option is introduced to allow this support to be disabled for those that don't require it. Inspired by an earlier patch by Leonid Yegoshin, but implemented more cleanly & correctly. Signed-off-by: Paul Burton <paul.burton@imgtec.com> Cc: linux-mips@linux-mips.org Cc: Paul Burton <paul.burton@imgtec.com> Patchwork: https://patchwork.linux-mips.org/patch/6154/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
* update David Miller's old email addressJustin P. Mattock2011-04-061-1/+1
| | | | | | Signed-off-by: Justin P. Mattock <justinmattock@gmail.com> Acked-by: David S. Miller <davem@davemloft.net> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
* [MIPS] Check FCSR for pending interrupts, alternative versionAtsushi Nemoto2007-03-171-16/+0
| | | | | | | | | | | Commit 6d6671066a311703bca1b91645bb1e04cc983387 is incomplete and misses non-r4k CPUs. This patch reverts the commit and fixes in other way. o Do FCSR checking in caller of restore_fp_context. o Send SIGFPE if the signal handler set any FPU exception bits. Signed-off-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp> Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
* [MIPS] Move .set reorder out of conditional codeChris Dearman2007-02-061-1/+2
| | | | | Signed-off-by: Chris Dearman <chris@mips.com> Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
* [MIPS] Check FCSR for pending interrupts before restoring from a context.Chris Dearman2007-02-061-0/+16
| | | | | Signed-off-by: Chris Dearman <chris@mips.com> Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
* Remove obsolete #include <linux/config.h>Jörn Engel2006-06-301-1/+0
| | | | | Signed-off-by: Jörn Engel <joern@wohnheim.fh-wedel.de> Signed-off-by: Adrian Bunk <bunk@stusta.de>
* Support the MIPS32 / MIPS64 DSP ASE.Ralf Baechle2005-10-291-4/+1
| | | | Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
* kbuild: mips use generic asm-offsets.h supportSam Ravnborg2005-09-091-1/+1
| | | | | | | | | Removed obsolete stuff from arch makefile. mips had a special rule for generating asm-offsets.h so preserved it using an architecture specific hook in top-level Kbuild file. Renamed .h file to asm-offsets.h Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
* [PATCH] mips: clean up 32/64-bit configurationRalf Baechle2005-09-051-2/+2
| | | | | | | | Start cleaning 32-bit vs. 64-bit configuration. Signed-off-by: Ralf Baechle <ralf@linux-mips.org> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* Linux-2.6.12-rc2v2.6.12-rc2Linus Torvalds2005-04-161-0/+191
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
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