summaryrefslogtreecommitdiff
path: root/arch/mips/math-emu/cp1emu.c
AgeCommit message (Collapse)Author
2016-08-06Merge branch 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linusLinus Torvalds
Pull MIPS updates from Ralf Baechle: "This is the main pull request for MIPS for 4.8. Also includes is a minor SSB cleanup as SSB code traditionally is merged through the MIPS tree: ATH25: - MIPS: Add default configuration for ath25 Boot: - For zboot, copy appended dtb to the end of the kernel - store the appended dtb address in a variable BPF: - Fix off by one error in offset allocation Cobalt code: - Fix typos Core code: - debugfs_create_file returns NULL on error, so don't use IS_ERR for testing for errors. - Fix double locking issue in RM7000 S-cache code. This would only affect RM7000 ARC systems on reboot. - Fix page table corruption on THP permission changes. - Use compat_sys_keyctl for 32 bit userspace on 64 bit kernels. David says, there are no compatibility issues raised by this fix. - Move some signal code around. - Rewrite r4k count/compare clockevent device registration such that min_delta_ticks/max_delta_ticks files are guaranteed to be initialized. - Only register r4k count/compare as clockevent device if we can assume the clock to be constant. - Fix MSA asm warnings in control reg accessors - uasm and tlbex fixes and tweaking. - Print segment physical address when EU=1. - Define AT_VECTOR_SIZE_ARCH for ARCH_DLINFO. - CP: Allow booting by VP other than VP 0 - Cache handling fixes and optimizations for r4k class caches - Add hotplug support for R6 processors - Cleanup hotplug bits in kconfig - traps: return correct si code for accessing nonmapped addresses - Remove cpu_has_safe_index_cacheops Lantiq: - Register IRQ handler for virtual IRQ number - Fix EIU interrupt loading code - Use the real EXIN count - Fix build error. Loongson 3: - Increase HPET_MIN_PROG_DELTA and decrease HPET_MIN_CYCLES Octeon: - Delete built-in DTB pruning code for D-Link DSR-1000N. - Clean up GPIO definitions in dlink_dsr-1000n.dts. - Add more LEDs to the DSR-100n DTS - Fix off by one in octeon_irq_gpio_map() - Typo fixes - Enable SATA by default in cavium_octeon_defconfig - Support readq/writeq() - Remove forced mappings of USB interrupts. - Ensure DMA descriptors are always in the low 4GB - Improve USB reset code for OCTEON II. Pistachio: - Add maintainers entry for pistachio SoC Support - Remove plat_setup_iocoherency Ralink: - Fix pwm UART in spis group pinmux. SSB: - Change bare unsigned to unsigned int to suit coding style Tools: - Fix reloc tool compiler warnings. Other: - Delete use of ARCH_WANT_OPTIONAL_GPIOLIB" * 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus: (61 commits) MIPS: mm: Fix definition of R6 cache instruction MIPS: tools: Fix relocs tool compiler warnings MIPS: Cobalt: Fix typo MIPS: Octeon: Fix typo MIPS: Lantiq: Fix build failure MIPS: Use CPHYSADDR to implement mips32 __pa MIPS: Octeon: Dlink_dsr-1000n.dts: add more leds. MIPS: Octeon: Clean up GPIO definitions in dlink_dsr-1000n.dts. MIPS: Octeon: Delete built-in DTB pruning code for D-Link DSR-1000N. MIPS: store the appended dtb address in a variable MIPS: ZBOOT: copy appended dtb to the end of the kernel MIPS: ralink: fix spis group pinmux MIPS: Factor o32 specific code into signal_o32.c MIPS: non-exec stack & heap when non-exec PT_GNU_STACK is present MIPS: Use per-mm page to execute branch delay slot instructions MIPS: Modify error handling MIPS: c-r4k: Use SMP calls for CM indexed cache ops MIPS: c-r4k: Avoid small flush_icache_range SMP calls MIPS: c-r4k: Local flush_icache_range cache op override MIPS: c-r4k: Split r4k_flush_kernel_vmap_range() ...
2016-08-04tree-wide: replace config_enabled() with IS_ENABLED()Masahiro Yamada
The use of config_enabled() against config options is ambiguous. In practical terms, config_enabled() is equivalent to IS_BUILTIN(), but the author might have used it for the meaning of IS_ENABLED(). Using IS_ENABLED(), IS_BUILTIN(), IS_MODULE() etc. makes the intention clearer. This commit replaces config_enabled() with IS_ENABLED() where possible. This commit is only touching bool config options. I noticed two cases where config_enabled() is used against a tristate option: - config_enabled(CONFIG_HWMON) [ drivers/net/wireless/ath/ath10k/thermal.c ] - config_enabled(CONFIG_BACKLIGHT_CLASS_DEVICE) [ drivers/gpu/drm/gma500/opregion.c ] I did not touch them because they should be converted to IS_BUILTIN() in order to keep the logic, but I was not sure it was the authors' intention. Link: http://lkml.kernel.org/r/1465215656-20569-1-git-send-email-yamada.masahiro@socionext.com Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Acked-by: Kees Cook <keescook@chromium.org> Cc: Stas Sergeev <stsp@list.ru> Cc: Matt Redfearn <matt.redfearn@imgtec.com> Cc: Joshua Kinard <kumba@gentoo.org> Cc: Jiri Slaby <jslaby@suse.com> Cc: Bjorn Helgaas <bhelgaas@google.com> Cc: Borislav Petkov <bp@suse.de> Cc: Markos Chandras <markos.chandras@imgtec.com> Cc: "Dmitry V. Levin" <ldv@altlinux.org> Cc: yu-cheng yu <yu-cheng.yu@intel.com> Cc: James Hogan <james.hogan@imgtec.com> Cc: Brian Gerst <brgerst@gmail.com> Cc: Johannes Berg <johannes@sipsolutions.net> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Will Drewry <wad@chromium.org> Cc: Nikolay Martynov <mar.kolya@gmail.com> Cc: Huacai Chen <chenhc@lemote.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Daniel Borkmann <daniel@iogearbox.net> Cc: Leonid Yegoshin <Leonid.Yegoshin@imgtec.com> Cc: Rafal Milecki <zajec5@gmail.com> Cc: James Cowgill <James.Cowgill@imgtec.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Alex Smith <alex.smith@imgtec.com> Cc: Adam Buchbinder <adam.buchbinder@gmail.com> Cc: Qais Yousef <qais.yousef@imgtec.com> Cc: Jiang Liu <jiang.liu@linux.intel.com> Cc: Mikko Rapeli <mikko.rapeli@iki.fi> Cc: Paul Gortmaker <paul.gortmaker@windriver.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: Brian Norris <computersforpeace@gmail.com> Cc: Hidehiro Kawai <hidehiro.kawai.ez@hitachi.com> Cc: "Luis R. Rodriguez" <mcgrof@do-not-panic.com> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Ingo Molnar <mingo@redhat.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> Cc: Roland McGrath <roland@hack.frob.com> Cc: Paul Burton <paul.burton@imgtec.com> Cc: Kalle Valo <kvalo@qca.qualcomm.com> Cc: Viresh Kumar <viresh.kumar@linaro.org> Cc: Tony Wu <tung7970@gmail.com> Cc: Huaitong Han <huaitong.han@intel.com> Cc: Sumit Semwal <sumit.semwal@linaro.org> Cc: Alexei Starovoitov <ast@kernel.org> Cc: Juergen Gross <jgross@suse.com> Cc: Jason Cooper <jason@lakedaemon.net> Cc: "David S. Miller" <davem@davemloft.net> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Andrea Gelmini <andrea.gelmini@gelma.net> Cc: David Woodhouse <dwmw2@infradead.org> Cc: Marc Zyngier <marc.zyngier@arm.com> Cc: Rabin Vincent <rabin@rab.in> Cc: "Maciej W. Rozycki" <macro@imgtec.com> Cc: David Daney <david.daney@cavium.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-08-02MIPS: Use per-mm page to execute branch delay slot instructionsPaul Burton
In some cases the kernel needs to execute an instruction from the delay slot of an emulated branch instruction. These cases include: - Emulated floating point branch instructions (bc1[ft]l?) for systems which don't include an FPU, or upon which the kernel is run with the "nofpu" parameter. - MIPSr6 systems running binaries targeting older revisions of the architecture, which may include branch instructions whose encodings are no longer valid in MIPSr6. Executing instructions from such delay slots is done by writing the instruction to memory followed by a trap, as part of an "emuframe", and executing it. This avoids the requirement of an emulator for the entire MIPS instruction set. Prior to this patch such emuframes are written to the user stack and executed from there. This patch moves FP branch delay emuframes off of the user stack and into a per-mm page. Allocating a page per-mm leaves userland with access to only what it had access to previously, and compared to other solutions is relatively simple. When a thread requires a delay slot emulation, it is allocated a frame. A thread may only have one frame allocated at any one time, since it may only ever be executing one instruction at any one time. In order to ensure that we can free up allocated frame later, its index is recorded in struct thread_struct. In the typical case, after executing the delay slot instruction we'll execute a break instruction with the BRK_MEMU code. This traps back to the kernel & leads to a call to do_dsemulret which frees the allocated frame & moves the user PC back to the instruction that would have executed following the emulated branch. In some cases the delay slot instruction may be invalid, such as a branch, or may trigger an exception. In these cases the BRK_MEMU break instruction will not be hit. In order to ensure that frames are freed this patch introduces dsemul_thread_cleanup() and calls it to free any allocated frame upon thread exit. If the instruction generated an exception & leads to a signal being delivered to the thread, or indeed if a signal simply happens to be delivered to the thread whilst it is executing from the struct emuframe, then we need to take care to exit the frame appropriately. This is done by either rolling back the user PC to the branch or advancing it to the continuation PC prior to signal delivery, using dsemul_thread_rollback(). If this were not done then a sigreturn would return to the struct emuframe, and if that frame had meanwhile been used in response to an emulated branch instruction within the signal handler then we would execute the wrong user code. Whilst a user could theoretically place something like a compact branch to self in a delay slot and cause their thread to become stuck in an infinite loop with the frame never being deallocated, this would: - Only affect the users single process. - Be architecturally invalid since there would be a branch in the delay slot, which is forbidden. - Be extremely unlikely to happen by mistake, and provide a program with no more ability to harm the system than a simple infinite loop would. If a thread requires a delay slot emulation & no frame is available to it (ie. the process has enough other threads that all frames are currently in use) then the thread joins a waitqueue. It will sleep until a frame is freed by another thread in the process. Since we now know whether a thread has an allocated frame due to our tracking of its index, the cookie field of struct emuframe is removed as we can be more certain whether we have a valid frame. Since a thread may only ever have a single frame at any given time, the epc field of struct emuframe is also removed & the PC to continue from is instead stored in struct thread_struct. Together these changes simplify & shrink struct emuframe somewhat, allowing twice as many frames to fit into the page allocated for them. The primary benefit of this patch is that we are now free to mark the user stack non-executable where that is possible. Signed-off-by: Paul Burton <paul.burton@imgtec.com> Cc: Leonid Yegoshin <leonid.yegoshin@imgtec.com> Cc: Maciej Rozycki <maciej.rozycki@imgtec.com> Cc: Faraz Shahbazker <faraz.shahbazker@imgtec.com> Cc: Raghu Gandham <raghu.gandham@imgtec.com> Cc: Matthew Fortune <matthew.fortune@imgtec.com> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/13764/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2016-07-05MIPS: inst.h: Rename cbcond{0,1}_op to pop{1,3}0_opPaul Burton
The opcodes currently defined in inst.h as cbcond0_op & cbcond1_op are actually defined in the MIPS base instruction set manuals as pop10 & pop30 respectively. Rename them as such, for consistency with the documentation. Signed-off-by: Paul Burton <paul.burton@imgtec.com> Signed-off-by: James Hogan <james.hogan@imgtec.com> Acked-by: Ralf Baechle <ralf@linux-mips.org> Cc: linux-mips@linux-mips.org Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-07-05MIPS: inst.h: Rename b{eq,ne}zcji[al]c_op to pop{6,7}6_opPaul Burton
The opcodes currently defined in inst.h as beqzcjic_op & bnezcjialc_op are actually defined in the MIPS base instruction set manuals as pop66 & pop76 respectively. Rename them as such, for consistency with the documentation. Signed-off-by: Paul Burton <paul.burton@imgtec.com> Signed-off-by: James Hogan <james.hogan@imgtec.com> Acked-by: Ralf Baechle <ralf@linux-mips.org> Cc: linux-mips@linux-mips.org Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-05-13MIPS: math-emu: Fix jalr emulation when rd == $0Paul Burton
When emulating a jalr instruction with rd == $0, the code in isBranchInstr was incorrectly writing to GPR $0 which should actually always remain zeroed. This would lead to any further instructions emulated which use $0 operating on a bogus value until the task is next context switched, at which point the value of $0 in the task context would be restored to the correct zero by a store in SAVE_SOME. Fix this by not writing to rd if it is $0. Fixes: 102cedc32a6e ("MIPS: microMIPS: Floating point support.") Signed-off-by: Paul Burton <paul.burton@imgtec.com> Cc: Maciej W. Rozycki <macro@imgtec.com> Cc: James Hogan <james.hogan@imgtec.com> Cc: linux-mips@linux-mips.org Cc: linux-kernel@vger.kernel.org Cc: stable <stable@vger.kernel.org> # v3.10 Patchwork: https://patchwork.linux-mips.org/patch/13160/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2016-05-13MIPS: math-emu: Emulate MIPSr6 sel.fmt instructionPaul Burton
Add support for emulating the MIPSr6 sel.fmt instruction, which was previously missing from the FPU emulation code. This instruction selects its result from 2 possible source registers, based upon bit 0 of the destination register, and is valid only for S (single) & D (double) data types. Signed-off-by: Paul Burton <paul.burton@imgtec.com> Cc: Maciej W. Rozycki <macro@imgtec.com> Cc: James Hogan <james.hogan@imgtec.com> Cc: linux-mips@linux-mips.org Cc: linux-kernel@vger.kernel.org Patchwork: https://patchwork.linux-mips.org/patch/13153/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2016-05-13MIPS: math-emu: Fix BC1{EQ,NE}Z emulationPaul Burton
The conditions for branching when emulating the BC1EQZ & BC1NEZ instructions were backwards, leading to each of those instructions being treated as the other. Fix this by reversing the conditions, and clear up the code a little for readability & checkpatch. Fixes: c909ca718e8f ("MIPS: math-emu: Emulate missing BC1{EQ,NE}Z instructions") Signed-off-by: Paul Burton <paul.burton@imgtec.com> Reviewed-by: James Hogan <james.hogan@imgtec.com> Cc: Maciej W. Rozycki <macro@imgtec.com> Cc: linux-mips@linux-mips.org Cc: linux-kernel@vger.kernel.org Patchwork: https://patchwork.linux-mips.org/patch/13150/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2016-01-24MIPS: math-emu: Correctly handle NOP emulationMaciej W. Rozycki
Fix an issue introduced with commit 9ab4471c9f1b ("MIPS: math-emu: Correct delay-slot exception propagation") where the emulation of a NOP instruction signals the need to terminate the emulation loop. This in turn, if the PC has not changed from the entry to the loop, will cause the kernel to terminate the program with SIGILL. Consider this program: static double div(double d) { do d /= 2.0; while (d > .5); return d; } int main(int argc, char **argv) { return div(argc); } which gets compiled to the following binary code: 00400490 <main>: 400490: 44840000 mtc1 a0,$f0 400494: 3c020040 lui v0,0x40 400498: d44207f8 ldc1 $f2,2040(v0) 40049c: 46800021 cvt.d.w $f0,$f0 4004a0: 46220002 mul.d $f0,$f0,$f2 4004a4: 4620103c c.lt.d $f2,$f0 4004a8: 4501fffd bc1t 4004a0 <main+0x10> 4004ac: 00000000 nop 4004b0: 4620000d trunc.w.d $f0,$f0 4004b4: 03e00008 jr ra 4004b8: 44020000 mfc1 v0,$f0 4004bc: 00000000 nop Where the FPU emulator is used, depending on the number of command-line arguments this code will either run to completion or terminate with SIGILL. If no arguments are specified, then BC1T will not be taken, NOP will not be emulated and code will complete successfully. If one argument is specified, then BC1T will be taken once and NOP will be emulated. At this point the entry PC value will be 0x400498 and the new PC value, set by `mips_dsemul' will be 0x4004a0, the target of BC1T. The emulation loop will terminate, but SIGILL will not be issued, because the PC has changed. The FPU emulator will be entered again and on the second execution BC1T will not be taken, NOP will not be emulated and code will complete successfully. If two or more arguments are specified, then the first execution of BC1T will proceed as above. Upon reentering the FPU emulator the emulation loop will continue to BC1T, at which point the branch will be taken and NOP emulated again. At this point however the entry PC value will be 0x4004a0, the same as the target of BC1T. This will make the emulator conclude that execution has not advanced and therefore an unsupported FPU instruction has been encountered, and SIGILL will be sent to the process. Fix the problem by extending the internal API of `mips_dsemul', making it return -1 if no delay slot emulation frame has been made, the instruction has been handled and execution of the emulation loop needs to continue as if nothing happened. Remove code from `mips_dsemul' to reproduce steps made by the emulation loop at the conclusion of each iteration, as those will be reached normally now. Adjust call sites accordingly. Document the API. Signed-off-by: Maciej W. Rozycki <macro@imgtec.com> Cc: Aurelien Jarno <aurelien@aurel32.net> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/12172/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2015-09-03MIPS: math-emu: Add support for the MIPS R6 MAX{, A} FPU instructionMarkos Chandras
MIPS R6 introduced the following instruction: Scalar Floating-Point Maximum and Scalar Floating-Point argument with Maximum Absolute Value MAX.fmt writes the maximum value of the inputs fs and ft to the destination fd. MAXA.fmt takes input arguments fs and ft and writes the argument with the maximum absolute value to the destination fd. Signed-off-by: Markos Chandras <markos.chandras@imgtec.com> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/10961/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2015-09-03MIPS: math-emu: Add support for the MIPS R6 MIN{, A} FPU instructionMarkos Chandras
MIPS R6 introduced the following instruction: Scalar Floating-Point Minimum and Scalar Floating-Point argument with Minimum Absolute Value MIN.fmt writes the minimum value of the inputs fs and ft to the destination fd. MINA.fmt takes input arguments fs and ft and writes the argument with the minimum absolute value to the destination fd. Signed-off-by: Markos Chandras <markos.chandras@imgtec.com> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/10960/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2015-09-03MIPS: math-emu: Add support for the MIPS R6 CLASS FPU instructionMarkos Chandras
MIPS R6 introduced the following instruction: Stores in fd a bit mask reflecting the floating-point class of the floating point scalar value fs. CLASS.fmt: FPR[fd] = class(FPR[fs]) Signed-off-by: Markos Chandras <markos.chandras@imgtec.com> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/10959/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2015-09-03MIPS: math-emu: Add support for the MIPS R6 RINT FPU instructionMarkos Chandras
MIPS R6 introduced the following instruction: Floating-Point Round to Integral Scalar floating-point round to integral floating point value. RINT.fmt: FPR[fd] = round_int(FPR[fs]) Signed-off-by: Markos Chandras <markos.chandras@imgtec.com> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/10958/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2015-09-03MIPS: math-emu: Add support for the MIPS R6 MSUBF FPU instructionMarkos Chandras
MIPS R6 introduced the following instruction: Floating Point Fused Multiply Subtract: MSUBF.fmt To perform a fused multiply-subtract of FP values. MSUBF.fmt: FPR[fd] = FPR[fd] - (FPR[fs] x FPR[ft]) Signed-off-by: Markos Chandras <markos.chandras@imgtec.com> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/10957/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2015-09-03MIPS: math-emu: Add support for the MIPS R6 MADDF FPU instructionMarkos Chandras
MIPS R6 introduced the following instruction: Floating Point Fused Multiply Add: MADDF.fmt To perform a fused multiply-add of FP values. MADDF.fmt: FPR[fd] = FPR[fd] + (FPR[fs] x FPR[ft]) Signed-off-by: Markos Chandras <markos.chandras@imgtec.com> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/10956/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2015-09-03MIPS: math-emu: Add support for the MIPS R6 SELNEZ FPU instructionMarkos Chandras
MIPS R6 introduced the following instruction: SELNEZ.fmt: FPR[fd]  FPR[ft].bit0 ? FPR[fs] : 0 Add support for emulating the single and double precision formats of the said instruction. Signed-off-by: Markos Chandras <markos.chandras@imgtec.com> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/10955/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2015-09-03MIPS: math-emu: Add support for the MIPS R6 SELEQZ FPU instructionMarkos Chandras
MIPS R6 introduced the following instruction: SELEQZ.fmt: FPR[fd]  FPR[ft].bit0 ? 0 : FPR[fs] Add support for emulating the single and double precision formats of the said instruction. Signed-off-by: Markos Chandras <markos.chandras@imgtec.com> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/10954/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2015-09-03MIPS: math-emu: Add support for the CMP.condn.fmt R6 instructionMarkos Chandras
Add support for emulating the new CMP.condn.fmt R6 instructions and return SIGILL for the old C.cond.fmt if R2 emulation is not enabled since it's not supported by R6. The functionality of the new CMP.condn.fmt is the following one: If the comparison specified by the condn field of the instruction is true for the operand values, the result is true; otherwise, the result is false. If no exception is taken, the result is written into FPR fd; true is all 1s and false is all 0s repeated the operand width of fmt. All other bits beyond the operand width fmt are UNPREDICTABLE. Signed-off-by: Markos Chandras <markos.chandras@imgtec.com> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/10953/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2015-09-03MIPS: math-emu: Emulate missing BC1{EQ,NE}Z instructionsMarkos Chandras
Commit c8a34581ec09 ("MIPS: Emulate the BC1{EQ,NE}Z FPU instructions") added support for emulating the new R6 BC1{EQ,NE}Z branches but it missed the case where the instruction that caused the exception was not on a DS. Signed-off-by: Markos Chandras <markos.chandras@imgtec.com> Fixes: c8a34581ec09 ("MIPS: Emulate the BC1{EQ,NE}Z FPU instructions") Cc: <stable@vger.kernel.org> # 4.0+ Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/10738/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2015-09-03MIPS: math-emu: Allow m{f,t}hc emulation on MIPS R6Markos Chandras
The mfhc/mthc instructions are supported on MIPS R6 so emulate them if needed. Signed-off-by: Markos Chandras <markos.chandras@imgtec.com> Cc: <stable@vger.kernel.org> # 4.0+ Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/10737/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2015-09-03MIPS: cp1emu: Fix closing bracket for the d_fmt caseMarkos Chandras
The double format (d_fmt) case uses an opening bracket which then closes at the end of the word format (w_fmt). This can be rather confusing so add the closing bracket at the end of the d_fmt case and use another one for the w_fmt one. Signed-off-by: Markos Chandras <markos.chandras@imgtec.com> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/10733/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2015-07-09MIPS: Fix erroneous JR emulation for MIPS R6Markos Chandras
Commit 5f9f41c474befb4ebbc40b27f65bb7d649241581 ("MIPS: kernel: Prepare the JR instruction for emulation on MIPS R6") added support for emulating the JR instruction on MIPS R6 cores but that introduced a bug which could be triggered when hitting a JALR opcode because the code used the wrong field in the 'r_format' struct to determine the instruction opcode. This lead to crashes because an emulated JALR instruction was treated as a JR one when the R6 emulator was turned off. Fixes: 5f9f41c474be ("MIPS: kernel: Prepare the JR instruction for emulation on MIPS R6") Cc: <stable@vger.kernel.org> # 4.0+ Signed-off-by: Markos Chandras <markos.chandras@imgtec.com> Cc: linux-mips@linux-mips.org Cc: stable@vger.kernel.org Patchwork: https://patchwork.linux-mips.org/patch/10583/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2015-07-09MIPS: Fix branch emulation for BLTC and BGEC instructionsMarkos Chandras
Commits f1b44067c19258b7614e3cd09dfe8d8e12ff5895 ("MIPS: Emulate the new MIPS R6 B{L,G}T{Z,}{AL,}C instructions") and commit a8ff66f52d3f17b5ae793955270675c197f73d6c ("MIPS: Emulate the new MIPS R6 B{L,G}E{Z,}{AL,}C instructions") added support for emulating various branch compact instructions. However, it missed the case for those which use the old BLEZL and BGTZL opcodes leading to random crashes when the R6 emulator is disabled. We fix this by ensuring that the 'rt' field is not zero which is always true for these branch compact instructions. Fixes: f1b44067c192 ("MIPS: Emulate the new MIPS R6 B{L,G}T{Z,}{AL,}C instructions") Fixes: a8ff66f52d3f ("MIPS: Emulate the new MIPS R6 B{L,G}E{Z,}{AL,}C instructions") Cc: <stable@vger.kernel.org> # 4.0+ Signed-off-by: Markos Chandras <markos.chandras@imgtec.com> Cc: linux-mips@linux-mips.org Cc: Markos Chandras <markos.chandras@imgtec.com> Patchwork: https://patchwork.linux-mips.org/patch/10582/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2015-05-12MIPS: Fix a preemption issue with thread's FPU defaultsMaciej W. Rozycki
Fix "BUG: using smp_processor_id() in preemptible" reported in accesses to thread's FPU defaults: the value to initialise FSCR to at program startup, the FCSR r/w mask and the contents of FIR in full FPU emulation, removing a regression introduced with 9b26616c [MIPS: Respect the ISA level in FCSR handling] and f6843626 [MIPS: math-emu: Set FIR feature flags for full emulation]. Use `boot_cpu_data' to obtain the data from, following the approach that `cpu_has_*' macros take and avoiding the call to `smp_processor_id' made in the reference to `current_cpu_data'. The contents of FSCR have to be consistent across processors in an SMP system, the settings there must not change as a thread is migrated across processors. And the contents of FIR are guaranteed to be consistent in FPU emulation, by definition. Signed-off-by: Maciej W. Rozycki <macro@linux-mips.org> Tested-by: Ezequiel Garcia <ezequiel.garcia@imgtec.com> Tested-by: Paul Martin <paul.martin@codethink.co.uk> Cc: Markos Chandras <Markos.Chandras@imgtec.com> Cc: James Hogan <james.hogan@imgtec.com> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/10030/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2015-04-08MIPS: Respect the ISA level in FCSR handlingMaciej W. Rozycki
Define the central place the default FCSR value is set from, initialised in `cpu_probe'. Determine the FCSR mask applied to values written to the register with CTC1 in the full emulation mode and via ptrace(2), according to the ISA level of processor hardware or the writability of bits 31:18 if actual FPU hardware is used. Software may rely on FCSR bits whose functions our emulator does not implement, so it should not allow them to be set or software may get confused. For ptrace(2) it's just sanity. [ralf@linux-mips.org: Fixed double inclusion of <asm/current.h>.] Signed-off-by: Maciej W. Rozycki <macro@linux-mips.org> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/9711/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2015-04-08MIPS: math-emu: Define IEEE 754-2008 feature control bitsMaciej W. Rozycki
Define IEEE 754-2008 feature control bits: FIR.HAS2008, FCSR.ABS2008 and FCSR.NAN2008, and update the `_ieee754_csr' structure accordingly. For completeness define FIR.UFRP too. Signed-off-by: Maciej W. Rozycki <macro@linux-mips.org> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/9709/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2015-04-08MIPS: math-emu: Implement the FCCR, FEXR and FENR registersMaciej W. Rozycki
Implement the FCCR, FEXR and FENR "shadow" FPU registers for the architecture levels that include them, for the CFC1 and CTC1 instructions in the full emulation mode. For completeness add macros for the CP1 UFR and UNFR registers too, no actual implementation though. Signed-off-by: Maciej W. Rozycki <macro@linux-mips.org> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/9708/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2015-04-08MIPS: math-emu: Set FIR feature flags for full emulationMaciej W. Rozycki
Implement FIR feature flags in the FPU emulator according to features supported and architecture level requirements. The W, L and F64 bits have only been added at level #2 even though the features they refer to were also included with the MIPS64r1 ISA and the W fixed-point format also with the MIPS32r1 ISA. This is only relevant for the full emulation mode and the emulated CFC1 instruction as well as ptrace(2) accesses. Signed-off-by: Maciej W. Rozycki <macro@linux-mips.org> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/9707/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2015-04-08MIPS: math-emu: Correct delay-slot exception propagationMaciej W. Rozycki
Restore EPC at the branch whose delay slot is emulated if the delay-slot instruction signals. This is so that code in `fpu_emulator_cop1Handler' does not see EPC having advanced and mistakenly successfully resume userland execution from the location at the branch target in that case. Restoring EPC guarantees an immediate exit from the emulation loop and if EPC hasn't advanced at all since entering the loop, also issuing the signal reported by the delay-slot instruction. Signed-off-by: Maciej W. Rozycki <macro@linux-mips.org> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/9701/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2015-04-08MIPS: Correct FP ISA requirementsMaciej W. Rozycki
Correct ISA requirements for floating-point instructions: * the CU3 exception signifies a real COP3 instruction in MIPS I & II, * the BC1FL and BC1TL instructions are not supported in MIPS I, * the SQRT.fmt instructions are indeed supported in MIPS II, * the LDC1 and SDC1 instructions are indeed supported in MIPS32r1, * the CEIL.W.fmt, FLOOR.W.fmt, ROUND.W.fmt and TRUNC.W.fmt instructions are indeed supported in MIPS32, * the CVT.L.fmt and CVT.fmt.L instructions are indeed supported in MIPS32r2 and MIPS32r6, * the CEIL.L.fmt, FLOOR.L.fmt, ROUND.L.fmt and TRUNC.L.fmt instructions are indeed supported in MIPS32r2 and MIPS32r6, * the RSQRT.fmt and RECIP.fmt instructions are indeed supported in MIPS64r1, Also simplify conditionals for MIPS III and MIPS IV FPU instructions and the handling of the MOVCI minor opcode. Signed-off-by: Maciej W. Rozycki <macro@linux-mips.org> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/9700/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2015-04-08MIPS: math-emu: Factor out CFC1/CTC1 emulationMaciej W. Rozycki
Move CFC1/CTC1 emulation code to separate functions to avoid excessive indentation in forthcoming changes. Adjust formatting in a minor way and remove extraneous round brackets. Signed-off-by: Maciej W. Rozycki <macro@linux-mips.org> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/9682/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2015-04-08MIPS: math-emu: Remove `modeindex' macroMaciej W. Rozycki
Commit 56a64733 [MIPS: math-emu: Switch to using the MIPS rounding modes.] removed the distinction between hardware and emulator rounding mode encodings, the hardware encoding is now used in emulation as well. Complement the change and remove the `modeindex' macro previously used for indexing into encoding translation tables, it now does nothing and only obfuscates code by reinserting the value extracted from FCSR. Adjust comments accordingly. Signed-off-by: Maciej W. Rozycki <macro@linux-mips.org> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/9680/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2015-04-08MIPS: math-emu: Reindent `bc_op' emulationMaciej W. Rozycki
Correct the double-tab indentation of the branch-likely not-taken case. Signed-off-by: Maciej W. Rozycki <macro@linux-mips.org> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/9674/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2015-02-17MIPS: Handle MIPS IV, V and R2 FPU instructions on MIPS R6 as wellMarkos Chandras
MIPS R2 FPU instructions are also present in MIPS R6 so amend the preprocessor definitions to take MIPS R6 into consideration. Signed-off-by: Markos Chandras <markos.chandras@imgtec.com>
2015-02-17MIPS: kernel: mips-r2-to-r6-emul: Add R2 emulator for MIPS R6Leonid Yegoshin
MIPS R6 removed quite a few R2 instructions. However, there is plenty of <R6 userland code so we add an in-kernel emulator so we can still be able to execute all R2 userland out there. The emulator comes with a handy debugfs under /mips/ directory (r2-emul-stats) to provide some basic statistics of the instructions that are being emulated. Below are some statistics from booting a minimal buildroot image: Instruction Total BDslot ------------------------------ movs 236969 0 hilo 56686 0 muls 55279 0 divs 10941 0 dsps 0 0 bops 1 0 traps 0 0 fpus 0 0 loads 214981 17 stores 103364 0 llsc 56898 0 dsemul 150418 0 jr 370158 bltzl 43 bgezl 1594 bltzll 0 bgezll 0 bltzal 39 bgezal 39 beql 14503 bnel 138741 blezl 0 bgtzl 3988 Signed-off-by: Leonid Yegoshin <Leonid.Yegoshin@imgtec.com> Signed-off-by: Markos Chandras <markos.chandras@imgtec.com>
2015-02-17MIPS: Emulate the new MIPS R6 BNEZC and JIALC instructionsMarkos Chandras
MIPS R6 uses the <R6 sdc2 opcode for the new BNEZC and JIALC instructions Signed-off-by: Markos Chandras <markos.chandras@imgtec.com>
2015-02-17MIPS: Emulate the new MIPS R6 BEQZC and JIC instructionsMarkos Chandras
MIPS R6 uses the <R6 ldc2 opcode for the new BEQZC and JIC instructions Signed-off-by: Markos Chandras <markos.chandras@imgtec.com>
2015-02-17MIPS: Emulate the new MIPS R6 BALC instructionMarkos Chandras
MIPS R6 uses the <R6 swc2 opcode for the new BALC instructions. Signed-off-by: Markos Chandras <markos.chandras@imgtec.com>
2015-02-17MIPS: Emulate the new MIPS R6 BNVC, BNEC and BNEZLAC instructionsMarkos Chandras
MIPS R6 uses the <R6 DADDI opcode for the new BNVC, BNEC and BNEZLAC instructions. Signed-off-by: Markos Chandras <markos.chandras@imgtec.com>
2015-02-17MIPS: Emulate the new MIPS R6 BOVC, BEQC and BEQZALC instructionsMarkos Chandras
MIPS R6 uses the <R6 ADDI opcode for the new BOVC, BEQC and BEQZALC instructions. Signed-off-by: Markos Chandras <markos.chandras@imgtec.com>
2015-02-17MIPS: Emulate the new MIPS R6 branch compact (BC) instructionMarkos Chandras
MIPS R6 uses the <R6 LWC2 opcode for the new BC instruction. Signed-off-by: Markos Chandras <markos.chandras@imgtec.com>
2015-02-17MIPS: Emulate the new MIPS R6 B{L,G}T{Z,}{AL,}C instructionsMarkos Chandras
MIPS R6 added the following four instructions which share the BGTZ and BGTZL opcode: BLTZALC: Compact branch-and-link if GPR rt is < to zero BGTZALC: Compact branch-and-link if GPR rt is > to zero BLTZL : Compact branch if GPR rt is < to zero BGTZL : Compact branch if GPR rt is > to zero BLTC : Compact branch if GPR rs is less than GPR rt BLTUC : Similar to BLTC but unsigned Signed-off-by: Markos Chandras <markos.chandras@imgtec.com>
2015-02-17MIPS: Emulate the new MIPS R6 B{L,G}Ε{Z,}{AL,}C instructionsMarkos Chandras
MIPS R6 added the following four instructions which share the BLEZ and BLEZL opcodes: BLEZALC: Compact branch-and-link if GPR rt is <= to zero BGEZALC: Compact branch-and-link if GPR rt is >= to zero BLEZC : Compact branch if GPR rt is <= to zero BGEZC : Compact branch if GPR rt is >= to zero BGEC : Compact branch if GPR rs is less than or equal to GPR rt BGEUC : Similar to BGEC but unsigned. Signed-off-by: Markos Chandras <markos.chandras@imgtec.com>
2015-02-17MIPS: Emulate the BC1{EQ,NE}Z FPU instructionsMarkos Chandras
MIPS R6 introduced the following two branch instructions for COP1: BC1EQZ: Branch if Cop1 (FPR) Register Bit 0 is Equal to Zero BC1NEZ: Branch if Cop1 (FPR) Register Bit 0 is Not Equal to Zero Signed-off-by: Markos Chandras <markos.chandras@imgtec.com>
2015-02-17MIPS: kernel: branch: Do not emulate the branch likelies on MIPS R6Markos Chandras
MIPS R6 removed the BLTZL, BGEZL, BLTZAL, BGEZAL, BEQL, BNEL, BLEZL, BGTZL branch likely instructions so we must not try to emulate them on MIPS R6 if the R2-to-R6 emulator is not present. Signed-off-by: Markos Chandras <markos.chandras@imgtec.com>
2015-02-17MIPS: kernel: Prepare the JR instruction for emulation on MIPS R6Markos Chandras
The MIPS R6 JR instruction is an alias to the JALR one, so it may need emulation for non-R6 userlands. Signed-off-by: Markos Chandras <markos.chandras@imgtec.com>
2014-11-24MIPS: Support for hybrid FPRsPaul Burton
Hybrid FPRs is a scheme where scalar FP registers are 64b wide, but accesses to odd indexed single registers use bits 63:32 of the preceeding even indexed 64b register. In this mode all FP code except that built for the plain FP64 ABI can execute correctly. Most notably a combination of FP64A & FP32 code can execute correctly, allowing for existing FP32 binaries to be linked with new FP64A binaries that can make use of 64 bit FP & MSA. Hybrid FPRs are implemented by setting both the FR & FRE bits, trapping & emulating single precision FP instructions (via Reserved Instruction exceptions) whilst allowing others to execute natively. It therefore has a penalty in terms of execution speed, and should only be used when no fully native mode can be. As more binaries are recompiled to use either the FPXX or FP64(A) ABIs, the need for hybrid FPRs should diminish. However in the short to mid term it allows for a gradual transition towards that world, rather than a complete ABI break which is not feasible for some users & not desirable for many. A task will be executed using the hybrid FPR scheme when its TIF_HYBRID_FPREGS flag is set & TIF_32BIT_FPREGS is clear. A further patch will set the flags as necessary, this patch simply adds the infrastructure necessary for the hybrid FPR mode to work. Signed-off-by: Paul Burton <paul.burton@imgtec.com> Cc: linux-mips@linux-mips.org Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: linux-fsdevel@vger.kernel.org Cc: linux-kernel@vger.kernel.org Patchwork: https://patchwork.linux-mips.org/patch/7683/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2014-11-07MIPS: Fix build with binutils 2.24.51+Manuel Lauss
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>
2014-10-21MIPS: cp1emu: Fix ISA restrictions for cop1x_op instructionsMarkos Chandras
Commit 08a07904e1828 ("MIPS: math-emu: Remove most ifdefery") removed the #ifdef ISA conditions and switched to runtime detection. However, according to the instruction set manual, the cop1x_op instructions are available in >=MIPS32r2 as well. This fixes a problem on MIPS32r2 with the ntpd package which failed to execute with a SIGILL exit code due to the fact that a madd.d instruction was not being emulated. Signed-off-by: Markos Chandras <markos.chandras@imgtec.com> Fixes: 08a07904e1828 ("MIPS: math-emu: Remove most ifdefery") Cc: <stable@vger.kernel.org> # v3.16+ Cc: linux-mips@linux-mips.org Reviewed-by: Paul Burton <paul.burton@imgtec.com> Reviewed-by: James Hogan <james.hogan@imgtec.com> Cc: Markos Chandras <markos.chandras@imgtec.com> Patchwork: https://patchwork.linux-mips.org/patch/8173/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2014-09-26MIPS: Fix MFC1 & MFHC1 emulation for 64-bit MIPS systemsPaul Burton
Commit bbd426f542cb "MIPS: Simplify FP context access" modified the SIFROMREG & SIFROMHREG macros such that they return unsigned rather than signed 32b integers. I had believed that to be fine, but inadvertently missed the MFC1 & MFHC1 cases which write to a struct pt_regs regs element. On MIPS32 this is fine, but on 64 bit those saved regs' fields are 64 bit wide. Using unsigned values caused the 32 bit value from the FP register to be zero rather than sign extended as the architecture specifies, causing incorrect emulation of the MFC1 & MFHc1 instructions. Fix by reintroducing the casts to signed integers, and therefore the sign extension. Signed-off-by: Paul Burton <paul.burton@imgtec.com> Cc: stable@vger.kernel.org # v3.15+ Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/7848/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>