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* MIPS: Fix odd fp register warnings with MIPS64r2James Hogan2017-11-101-3/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Building 32-bit MIPS64r2 kernels produces warnings like the following on certain toolchains (such as GNU assembler 2.24.90, but not GNU assembler 2.28.51) since commit 22b8ba765a72 ("MIPS: Fix MIPS64 FP save/restore on 32-bit kernels"), due to the exposure of fpu_save_16odd from fpu_save_double and fpu_restore_16odd from fpu_restore_double: arch/mips/kernel/r4k_fpu.S:47: Warning: float register should be even, was 1 ... arch/mips/kernel/r4k_fpu.S:59: Warning: float register should be even, was 1 ... This appears to be because .set mips64r2 does not change the FPU ABI to 64-bit when -march=mips64r2 (or e.g. -march=xlp) is provided on the command line on that toolchain, from the default FPU ABI of 32-bit due to the -mabi=32. This makes access to the odd FPU registers invalid. Fix by explicitly changing the FPU ABI with .set fp=64 directives in fpu_save_16odd and fpu_restore_16odd, and moving the undefine of fp up in asmmacro.h so fp doesn't turn into $30. Fixes: 22b8ba765a72 ("MIPS: Fix MIPS64 FP save/restore on 32-bit kernels") 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+: 22b8ba765a72: MIPS: Fix MIPS64 FP save/restore on 32-bit kernels Cc: <stable@vger.kernel.org> # 4.0+ Patchwork: https://patchwork.linux-mips.org/patch/17656/
* MIPS: Fix MIPS64 FP save/restore on 32-bit kernelsJames Hogan2017-11-091-4/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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: Add a missing ".set pop" in an early commitHuacai Chen2016-09-131-0/+1
| | | | | | | | | | | | | | | Commit 842dfc11ea9a21 ("MIPS: Fix build with binutils 2.24.51+") missing a ".set pop" in macro fpu_restore_16even, so add it. Signed-off-by: Huacai Chen <chenhc@lemote.com> Acked-by: Manuel Lauss <manuel.lauss@gmail.com> Cc: Steven J . Hill <Steven.Hill@caviumnetworks.com> Cc: Fuxin Zhang <zhangfx@lemote.com> Cc: Zhangjin Wu <wuzhangjin@gmail.com> Cc: linux-mips@linux-mips.org Cc: stable@vger.kernel.org # 3.18+ Patchwork: https://patchwork.linux-mips.org/patch/14210/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
* MIPS: Fix little endian microMIPS MSA encodingsJames Hogan2016-05-281-49/+50
| | | | | | | | | | | | | | | | | | | | | | | | When the toolchain doesn't support MSA we encode MSA instructions explicitly in assembly. Unfortunately we use .word for both MIPS and microMIPS encodings which is wrong, since 32-bit microMIPS instructions are made up from a pair of halfwords. - The most significant halfword always comes first, so for little endian builds the halves will be emitted in the wrong order. - 32-bit alignment isn't guaranteed, so the assembler may insert a 16-bit nop instruction to pad the instruction stream to a 32-bit boundary. Use the new instruction encoding macros to encode microMIPS MSA instructions correctly. Fixes: d96cc3d1ec5d ("MIPS: Add microMIPS MSA support.") Signed-off-by: James Hogan <james.hogan@imgtec.com> Cc: Paul Burton <Paul.Burton@imgtec.com> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/13312/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
* MIPS: Fix MSA assembly warningsJames Hogan2016-05-091-0/+6
| | | | | | | | | | | | | | | | | Building an MSA capable kernel with a toolchain that supports MSA produces warnings such as this: arch/mips/kernel/r4k_fpu.S:229: Warning: the `msa' extension requires 64-bit FPRs This is due to ".set msa" without ".set fp=64" in the non doubleword MSA load/store macros, since MSA requires the 64-bit FPU registers (FR=1). Add the missing fp=64 in these macros to silence the warnings. Signed-off-by: James Hogan <james.hogan@imgtec.com> Cc: Paul Burton <paul.burton@imgtec.com> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/13063/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
* MIPS: Fix MSA assembly with big thread offsetsJames Hogan2016-05-091-66/+83
| | | | | | | | | | | | | | | | | | | | | | When lockdep is enabled on a 64-bit kernel the FPR offset into the thread structure exceeds the maximum range of the MSA ld.d/st.d instructions. For example THREAD_FPR31 = 4644 (instead of 2448), while the signed immediate field is only 10 bits with an implicit multiply by 8, giving a maximum offset of 511*8 = 4088. This isn't a problem when the toolchain doesn't support MSA as the ld_*/st_* macros perform the addition separately into $1 with [d]addui which has a 16bit signed immediate field. Fix the case where the toolchain does support MSA by doing a single addition of THREAD_FPR0 into $1 with [d]addui, and doing the ld_*/st_* relative to that. Signed-off-by: James Hogan <james.hogan@imgtec.com> Cc: Paul Burton <paul.burton@imgtec.com> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/13064/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
* MIPS: Fix MSA ld_*/st_* asm macros to use PTR_ADDUJames Hogan2016-05-091-8/+8
| | | | | | | | | | | | | | The MSA ld_*/st_* assembler macros for when the toolchain doesn't support MSA use addu to offset the base address. However it is a virtual memory pointer so fix it to use PTR_ADDU which expands to daddu for 64-bit kernels. Signed-off-by: James Hogan <james.hogan@imgtec.com> Cc: Paul Burton <paul.burton@imgtec.com> Cc: linux-mips@linux-mips.org Cc: <stable@vger.kernel.org> # 4.3.y- Patchwork: https://patchwork.linux-mips.org/patch/13062/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
* MIPS: Use copy_s.fmt rather than copy_u.fmtPaul Burton2016-05-091-12/+12
| | | | | | | | | | | | | | | | | | | | 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: Introduce accessors for MSA vector registersPaul Burton2015-09-031-0/+114
| | | | | | | | | | | | | | | | | | 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: asmmacro: Ensure 64-bit FP registers are used with MSAMarkos Chandras2015-06-241-0/+11
| | | | | | | | | | | | | | | | | | This silences warnings like the following one when building with the latest binutils: arch/mips/kernel/genex.S: Assembler messages: arch/mips/kernel/genex.S:438: Warning: the `msa' extension requires 64-bit FPRs [ralf@linux-mips.org: Markos says binutils 2.25 and some 2.24 snapshots are affected.] Signed-off-by: Markos Chandras <markos.chandras@imgtec.com> Reviewed-by: James Hogan <james.hogan@imgtec.com> Cc: Paul Burton <paul.burton@imgtec.com> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/9745/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
* Revert "MIPS: Don't assume 64-bit FP registers for context switch"James Hogan2015-03-271-64/+64
| | | | | | | | | | | | | | | | This reverts commit 02987633df7ba2f62967791dda816eb191d1add3. The basic premise of the patch was incorrect since MSA context (including FP state) is saved using st.d which stores two consecutive 64-bit words in memory rather than a single 128-bit word. This means that even with big endian MSA, the FP state is still in the first 64-bit word. Signed-off-by: James Hogan <james.hogan@imgtec.com> Signed-off-by: Paul Burton <paul.burton@imgtec.com> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/9168/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
* MIPS: wrap cfcmsa & ctcmsa accesses for toolchains with MSA supportPaul Burton2015-03-271-4/+20
| | | | | | | | | | | | | | | | | | | | | | Uses of the cfcmsa & ctcmsa instructions were not being wrapped by a macro in the case where the toolchain supports MSA, since the arguments exactly match a typical use of the instructions. However using current toolchains this leads to errors such as: arch/mips/kernel/genex.S:437: Error: opcode not supported on this processor: mips32r2 (mips32r2) `cfcmsa $5,1' Thus uses of the instructions must be in the context of a ".set msa" directive, however doing that from the users of the instructions would be messy due to the possibility that the toolchain does not support MSA. Fix this by renaming the macros (prepending an underscore) in order to avoid recursion when attempting to emit the instructions, and provide implementations for the TOOLCHAIN_SUPPORTS_MSA case which ".set msa" as appropriate. Signed-off-by: Paul Burton <paul.burton@imgtec.com> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/9163/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
* MIPS: remove MSA macro recursionPaul Burton2015-03-271-3/+31
| | | | | | | | | | | | | | | | | | | | | Recursive macros made the code more concise & worked great for the case where the toolchain doesn't support MSA. However, with toolchains which do support MSA they lead to build failures such as: arch/mips/kernel/r4k_switch.S: Assembler messages: arch/mips/kernel/r4k_switch.S:148: Error: invalid operands `insert.w $w(0+1)[2],$1' arch/mips/kernel/r4k_switch.S:148: Error: invalid operands `insert.w $w(0+1)[3],$1' arch/mips/kernel/r4k_switch.S:148: Error: invalid operands `insert.w $w((0+1)+1)[2],$1' arch/mips/kernel/r4k_switch.S:148: Error: invalid operands `insert.w $w((0+1)+1)[3],$1' ... Drop the recursion from msa_init_all_upper invoking the msa_init_upper macro explicitly for each vector register. Signed-off-by: Paul Burton <paul.burton@imgtec.com> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/9162/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
* MIPS: assume at as source/dest of MSA copy/insert instructionsPaul Burton2015-03-271-16/+12
| | | | | | | | | | | | | | | | | | | | | | | | | Assuming at ($1) as the source or destination register of copy or insert instructions: - Simplifies the macros providing those instructions for toolchains without MSA support. - Avoids an unnecessary move instruction when at is used as the source or destination register anyway. - Is sufficient for the uses to be introduced in the kernel by a subsequent patch. Note that due to a patch ordering snafu on my part this also fixes the currently broken build with MSA support enabled. The build has been broken since commit c9017757c532 "MIPS: init upper 64b of vector registers when MSA is first used", which this patch should have preceeded. Signed-off-by: Paul Burton <paul.burton@imgtec.com> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/9161/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
* MIPS: Push .set mips64r* into the functions needing itPaul Burton2015-03-271-8/+4
| | | | | | | | | | | | | | | | | | | | | | | | | 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_switch: Add support for MIPS R6Leonid Yegoshin2015-02-171-5/+7
| | | | | | | | | | Add the MIPS R6 related preprocessor definitions for save/restore FPU related functions. We also set the appropriate ISA level so the final return instruction "jr ra" will produce the correct opcode on R6. Signed-off-by: Leonid Yegoshin <Leonid.Yegoshin@imgtec.com> Signed-off-by: Markos Chandras <markos.chandras@imgtec.com>
* MIPS: asm: asmmacro: Replace "add" instructions with "addu"Markos Chandras2015-02-171-2/+2
| | | | | | | | | | | | | The "add" instruction is actually a macro in binutils and depending on the size of the immediate it can expand to an "addi" instruction. However, the "addi" instruction traps on overflows which is not something we want on address calculation. Link: http://www.linux-mips.org/archives/linux-mips/2015-01/msg00121.html Cc: Paul Burton <paul.burton@imgtec.com> Cc: Maciej W. Rozycki <macro@linux-mips.org> Cc: <stable@vger.kernel.org> # v3.15+ Signed-off-by: Markos Chandras <markos.chandras@imgtec.com>
* MIPS: asm: asmmacro: Add MIPS R6 support to the simple EI/DI variantsLeonid Yegoshin2015-02-171-1/+1
| | | | | | | | EI/DI instructions are available in MIPS R6 so add the needed definitions. 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 Lauss2014-11-071-0/+18
| | | | | | | | | | | | | | | | | | | | | | | | | 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>
* MIPS: init upper 64b of vector registers when MSA is first usedPaul Burton2014-08-021-0/+20
| | | | | | | | | | | | | | | | | | | When a task first makes use of MSA we need to ensure that the upper 64b of the vector registers are set to some value such that no information can be leaked to it from the previous task to use MSA context on the CPU. The architecture formerly specified that these bits would be cleared to 0 when a scalar FP instructions wrote to the aliased FP registers, which would have implicitly handled this as the kernel restored scalar FP context. However more recent versions of the specification now state that the value of the bits in such cases is unpredictable. Initialise them explictly to be sure, and set all the bits to 1 rather than 0 for consistency with the least significant 64b. Signed-off-by: Paul Burton <paul.burton@imgtec.com> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/7497/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
* MIPS: save/restore MSACSR register on context switchPaul Burton2014-08-021-0/+11
| | | | | | | | | | | I added a field for the MSACSR register in struct mips_fpu_struct, but never actually made use of it... This is a clear bug. Save and restore the MSACSR register along with the vector registers. Signed-off-by: Paul Burton <paul.burton@imgtec.com> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/7300/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
* MIPS: Add microMIPS MSA support.Steven J. Hill2014-06-041-8/+32
| | | | | | | | | | | This patch adds support for the microMIPS implementation of the MSA instructions. Signed-off-by: Steven J. Hill <Steven.Hill@imgtec.com> Reviewed-by: Paul Burton <Paul.Burton@imgtec.com> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/6763/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
* MIPS: MT: Remove SMTC supportRalf Baechle2014-05-241-20/+2
| | | | | | | | | | | | | | | Nobody is maintaining SMTC anymore and there also seems to be no userbase. Which is a pity - the SMTC technology primarily developed by Kevin D. Kissell <kevink@paralogos.com> is an ingenious demonstration for the MT ASE's power and elegance. Based on Markos Chandras <Markos.Chandras@imgtec.com> patch https://patchwork.linux-mips.org/patch/6719/ which while very similar did no longer apply cleanly when I tried to merge it plus some additional post-SMTC cleanup - SMTC was a feature as tricky to remove as it was to merge once upon a time. Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
* Merge branch '3.14-fixes' into mips-for-linux-nextRalf Baechle2014-03-311-2/+13
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| * MIPS: Make local_irq_disable macro safe for non-Mipsr2Jim Quinlan2014-03-201-0/+11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | For non-mipsr2 processors, the local_irq_disable contains an mfc0-mtc0 pair with instructions inbetween. With preemption enabled, this sequence may get preempted and effect a stale value of CP0_STATUS when executing the mtc0 instruction. This commit avoids this scenario by incrementing the preempt count before the mfc0 and decrementing it after the mtc9. [ralf@linux-mips.org: This patch is sorting out the part that were missed by e97c5b6098 [MIPS: Make irqflags.h functions preempt-safe for non-mipsr2 cpus.] I also re-enabled the inclusion of <asm/asm-offsets.h> at the top of <asm/asmmacro.h>]. Signed-off-by: Jim Quinlan <jim2101024@gmail.com> Cc: linux-mips@linux-mips.org Cc: cernekee@gmail.com Patchwork: https://patchwork.linux-mips.org/patch/6164/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
| * MIPS: Replace CONFIG_MIPS64 and CONFIG_MIPS32_R2Paul Bolle2014-03-141-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | 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: Basic MSA context switching supportPaul Burton2014-03-261-0/+70
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch adds support for context switching the MSA vector registers. These 128 bit vector registers are aliased with the FP registers - an FP register accesses the least significant bits of the vector register with which it is aliased (ie. the register with the same index). Due to both this & the requirement that the scalar FPU must be 64-bit (FR=1) if enabled at the same time as MSA the kernel will enable MSA & scalar FP at the same time for tasks which use MSA. If we restore the MSA vector context then we might as well enable the scalar FPU since the reason it was left disabled was to allow for lazy FP context restoring - but we just restored the FP context as it's a subset of the vector context. If we restore the FP context and have previously used MSA then we have to restore the whole vector context anyway (see comment in enable_restore_fp_context for details) so similarly we might as well enable MSA. Thus if a task does not use MSA then it will continue to behave as without this patch - the scalar FP context will be saved & restored as usual. But if a task executes an MSA instruction then it will save & restore the vector context forever more. Signed-off-by: Paul Burton <paul.burton@imgtec.com> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/6431/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
* | MIPS: Add MSA register definitions & accessPaul Burton2014-03-261-0/+121
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch introduces definitions for the MSA control registers and functions which allow access to both the control & vector registers. If the toolchain being used to build the kernel includes support for MSA then this patch will make use of that support & use MSA instructions directly. However toolchain support for MSA is very new & far from a point where it can be reasonably expected that everyone building the kernel uses a toolchain with support. Thus fallbacks using .word assembler directives are also provided for now as a temporary measure. Signed-off-by: Paul Burton <paul.burton@imgtec.com> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/6429/ Patchwork: https://patchwork.linux-mips.org/patch/6607/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
* | MIPS: Don't assume 64-bit FP registers for context switchPaul Burton2014-03-261-64/+64
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When saving or restoring scalar FP context we want to access the least significant 64 bits of each FP register. When the FP registers are 64 bits wide that is trivially the start of the registers value in memory. However when the FP registers are wider this equivalence will no longer be true for big endian systems. Define a new set of offset macros for the least significant 64 bits of each saved FP register within thread context, and make use of them when saving and restoring scalar FP context. Signed-off-by: Paul Burton <paul.burton@imgtec.com> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/6428/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
* | MIPS: Introduce _EXT assembler macroPaul Burton2014-03-061-0/+11
|/ | | | | | | | | | | This patch adds a simple macro to wrap the ext instruction which was introduced with MIPSR2, and fall back to a shift & and pair for pre-MIPSR2 CPUs. This will be used in a subsequent patch. Signed-off-by: Paul Burton <paul.burton@imgtec.com> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/6358/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
* MIPS: Support for 64-bit FP with O32 binariesPaul Burton2014-01-131-0/+107
| | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* MIPS: Use EI/DI for MIPS R2.David Daney2008-12-121-0/+10
| | | | | | | | | For MIPS R2, use the EI and DI instructions to enable and disable interrupts. Signed-off-by: Tomaso Paoletti <tpaoletti@caviumnetworks.com> Signed-off-by: David Daney <ddaney@caviumnetworks.com> Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
* MIPS: Move headfiles to new location below arch/mips/includeRalf Baechle2008-10-111-0/+82
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
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