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2015-03-27MIPS: KVM: Wire up MSA capabilityJames Hogan1-0/+18
Now that the code is in place for KVM to support MIPS SIMD Architecutre (MSA) in MIPS guests, wire up the new KVM_CAP_MIPS_MSA capability. For backwards compatibility, the capability must be explicitly enabled in order to detect or make use of MSA from the guest. The capability is not supported if the hardware supports MSA vector partitioning, since the extra support cannot be tested yet and it extends the state that the userland program would have to save. Signed-off-by: James Hogan <james.hogan@imgtec.com> Acked-by: Paolo Bonzini <pbonzini@redhat.com> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Gleb Natapov <gleb@kernel.org> Cc: Jonathan Corbet <corbet@lwn.net> Cc: linux-mips@linux-mips.org Cc: kvm@vger.kernel.org Cc: linux-api@vger.kernel.org Cc: linux-doc@vger.kernel.org
2015-03-27MIPS: KVM: Expose MSA registersJames Hogan2-2/+75
Add KVM register numbers for the MIPS SIMD Architecture (MSA) registers, and implement access to them with the KVM_GET_ONE_REG / KVM_SET_ONE_REG ioctls when the MSA capability is enabled (exposed in a later patch) and present in the guest according to its Config3.MSAP bit. The MSA vector registers use the same register numbers as the FPU registers except with a different size (128bits). Since MSA depends on Status.FR=1, these registers are inaccessible when Status.FR=0. These registers are returned as a single native endian 128bit value, rather than least significant half first with each 64-bit half native endian as the kernel uses internally. Signed-off-by: James Hogan <james.hogan@imgtec.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Paul Burton <paul.burton@imgtec.com> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Gleb Natapov <gleb@kernel.org> Cc: Jonathan Corbet <corbet@lwn.net> Cc: linux-mips@linux-mips.org Cc: kvm@vger.kernel.org Cc: linux-api@vger.kernel.org Cc: linux-doc@vger.kernel.org
2015-03-27MIPS: KVM: Add MSA exception handlingJames Hogan5-2/+140
Add guest exception handling for MIPS SIMD Architecture (MSA) floating point exceptions and MSA disabled exceptions. MSA floating point exceptions from the guest need passing to the guest kernel, so for these a guest MSAFPE is emulated. MSA disabled exceptions are normally handled by passing a reserved instruction exception to the guest (because no guest MSA was supported), but the hypervisor can now handle them if the guest has MSA by passing an MSA disabled exception to the guest, or if the guest has MSA enabled by transparently restoring the guest MSA context and enabling MSA and the FPU. Signed-off-by: James Hogan <james.hogan@imgtec.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Paul Burton <paul.burton@imgtec.com> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Gleb Natapov <gleb@kernel.org> Cc: linux-mips@linux-mips.org Cc: kvm@vger.kernel.org
2015-03-27MIPS: KVM: Emulate MSA bits in COP0 interfaceJames Hogan1-2/+35
Emulate MSA related parts of COP0 interface so that the guest will be able to enable/disable MSA (Config5.MSAEn) once the MSA capability has been wired up. As with the FPU (Status.CU1) setting Config5.MSAEn has no immediate effect if the MSA state isn't live, as MSA state is restored lazily on first use. Changes after the MSA state has been restored take immediate effect, so that the guest can start getting MSA disabled exceptions right away for guest MSA operations. The MSA state is saved lazily too, as MSA may get re-enabled in the near future anyway. A special case is also added for when Status.CU1 is set while FR=0 and the MSA state is live. In this case we are at risk of getting reserved instruction exceptions if we try and save the MSA state, so we lose the MSA state sooner while MSA is still usable. Signed-off-by: James Hogan <james.hogan@imgtec.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Paul Burton <paul.burton@imgtec.com> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Gleb Natapov <gleb@kernel.org> Cc: linux-mips@linux-mips.org Cc: kvm@vger.kernel.org
2015-03-27MIPS: KVM: Add base guest MSA supportJames Hogan6-19/+323
Add base code for supporting the MIPS SIMD Architecture (MSA) in MIPS KVM guests. MSA cannot yet be enabled in the guest, we're just laying the groundwork. As with the FPU, whether the guest's MSA context is loaded is stored in another bit in the fpu_inuse vcpu member. This allows MSA to be disabled when the guest disables it, but keeping the MSA context loaded so it doesn't have to be reloaded if the guest re-enables it. New assembly code is added for saving and restoring the MSA context, restoring only the upper half of the MSA context (for if the FPU context is already loaded) and for saving/clearing and restoring MSACSR (which can itself cause an MSA FP exception depending on the value). The MSACSR is restored before returning to the guest if MSA is already enabled, and the existing FP exception die notifier is extended to catch the possible MSA FP exception and step over the ctcmsa instruction. The helper function kvm_own_msa() is added to enable MSA and restore the MSA context if it isn't already loaded, which will be used in a later patch when the guest attempts to use MSA for the first time and triggers an MSA disabled exception. The existing FPU helpers are extended to handle MSA. kvm_lose_fpu() saves the full MSA context if it is loaded (which includes the FPU context) and both kvm_lose_fpu() and kvm_drop_fpu() disable MSA. kvm_own_fpu() also needs to lose any MSA context if FR=0, since there would be a risk of getting reserved instruction exceptions if CU1 is enabled and we later try and save the MSA context. We shouldn't usually hit this case since it will be handled when emulating CU1 changes, however there's nothing to stop the guest modifying the Status register directly via the comm page, which will cause this case to get hit. Signed-off-by: James Hogan <james.hogan@imgtec.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Paul Burton <paul.burton@imgtec.com> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Gleb Natapov <gleb@kernel.org> Cc: linux-mips@linux-mips.org Cc: kvm@vger.kernel.org
2015-03-27MIPS: KVM: Wire up FPU capabilityJames Hogan1-0/+37
Now that the code is in place for KVM to support FPU in MIPS KVM guests, wire up the new KVM_CAP_MIPS_FPU capability. For backwards compatibility, the capability must be explicitly enabled in order to detect or make use of the FPU from the guest. Signed-off-by: James Hogan <james.hogan@imgtec.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Gleb Natapov <gleb@kernel.org> Cc: Jonathan Corbet <corbet@lwn.net> Cc: linux-mips@linux-mips.org Cc: kvm@vger.kernel.org Cc: linux-api@vger.kernel.org Cc: linux-doc@vger.kernel.org
2015-03-27MIPS: KVM: Expose FPU registersJames Hogan2-11/+98
Add KVM register numbers for the MIPS FPU registers, and implement access to them with the KVM_GET_ONE_REG / KVM_SET_ONE_REG ioctls when the FPU capability is enabled (exposed in a later patch) and present in the guest according to its Config1.FP bit. The registers are accessible in the current mode of the guest, with each sized access showing what the guest would see with an equivalent access, and like the architecture they may become UNPREDICTABLE if the FR mode is changed. When FR=0, odd doubles are inaccessible as they do not exist in that mode. Signed-off-by: James Hogan <james.hogan@imgtec.com> Acked-by: Paolo Bonzini <pbonzini@redhat.com> Cc: Paul Burton <paul.burton@imgtec.com> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Gleb Natapov <gleb@kernel.org> Cc: Jonathan Corbet <corbet@lwn.net> Cc: linux-mips@linux-mips.org Cc: kvm@vger.kernel.org Cc: linux-api@vger.kernel.org Cc: linux-doc@vger.kernel.org
2015-03-27MIPS: KVM: Add FP exception handlingJames Hogan5-3/+88
Add guest exception handling for floating point exceptions and coprocessor 1 unusable exceptions. Floating point exceptions from the guest need passing to the guest kernel, so for these a guest FPE is emulated. Also, coprocessor 1 unusable exceptions are normally passed straight through to the guest (because no guest FPU was supported), but the hypervisor can now handle them if the guest has its FPU enabled by restoring the guest FPU context and enabling the FPU. Signed-off-by: James Hogan <james.hogan@imgtec.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Paul Burton <paul.burton@imgtec.com> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Gleb Natapov <gleb@kernel.org> Cc: linux-mips@linux-mips.org Cc: kvm@vger.kernel.org
2015-03-27MIPS: KVM: Emulate FPU bits in COP0 interfaceJames Hogan1-11/+100
Emulate FPU related parts of COP0 interface so that the guest will be able to enable/disable the following once the FPU capability has been wired up: - The FPU (Status.CU1) - 64-bit FP register mode (Status.FR) - Hybrid FP register mode (Config5.FRE) Changing Status.CU1 has no immediate effect if the FPU state isn't live, as the FPU state is restored lazily on first use. After that, changes take place immediately in the host Status.CU1, so that the guest can start getting coprocessor unusable exceptions right away for guest FPU operations if it is disabled. The FPU state is saved lazily too, as the FPU may get re-enabled in the near future anyway. Any change to Status.FR causes the FPU state to be discarded and FPU disabled, as the register state is architecturally UNPREDICTABLE after such a change. This should also ensure that the FPU state is fully initialised (with stale state, but that's fine) when it is next used in the new FP mode. Any change to the Config5.FRE bit is immediately updated in the host state so that the guest can get the relevant exceptions right away for single-precision FPU operations. Signed-off-by: James Hogan <james.hogan@imgtec.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Paul Burton <paul.burton@imgtec.com> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Gleb Natapov <gleb@kernel.org> Cc: linux-mips@linux-mips.org Cc: kvm@vger.kernel.org
2015-03-27MIPS: KVM: Add base guest FPU supportJames Hogan7-1/+333
Add base code for supporting FPU in MIPS KVM guests. The FPU cannot yet be enabled in the guest, we're just laying the groundwork. Whether the guest's FPU context is loaded is stored in a bit in the fpu_inuse vcpu member. This allows the FPU to be disabled when the guest disables it, but keeping the FPU context loaded so it doesn't have to be reloaded if the guest re-enables it. An fpu_enabled vcpu member stores whether userland has enabled the FPU capability (which will be wired up in a later patch). New assembly code is added for saving and restoring the FPU context, and for saving/clearing and restoring FCSR (which can itself cause an FP exception depending on the value). The FCSR is restored before returning to the guest if the FPU is already enabled, and a die notifier is registered to catch the possible FP exception and step over the ctc1 instruction. The helper function kvm_lose_fpu() is added to save FPU context and disable the FPU, which is used when saving hardware state before a context switch or KVM exit (the vcpu_get_regs() callback). The helper function kvm_own_fpu() is added to enable the FPU and restore the FPU context if it isn't already loaded, which will be used in a later patch when the guest attempts to use the FPU for the first time and triggers a co-processor unusable exception. The helper function kvm_drop_fpu() is added to discard the FPU context and disable the FPU, which will be used in a later patch when the FPU state will become architecturally UNPREDICTABLE (change of FR mode) to force a reload of [stale] context in the new FR mode. Signed-off-by: James Hogan <james.hogan@imgtec.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Paul Burton <paul.burton@imgtec.com> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Gleb Natapov <gleb@kernel.org> Cc: linux-mips@linux-mips.org Cc: kvm@vger.kernel.org
2015-03-27MIPS: KVM: Add vcpu_get_regs/vcpu_set_regs callbackJames Hogan3-0/+20
Add a vcpu_get_regs() and vcpu_set_regs() callbacks for loading and restoring context which may be in hardware registers. This may include floating point and MIPS SIMD Architecture (MSA) state which may be accessed directly by the guest (but restored lazily by the hypervisor), and also dedicated guest registers as provided by the VZ ASE. Signed-off-by: James Hogan <james.hogan@imgtec.com> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Gleb Natapov <gleb@kernel.org> Cc: linux-mips@linux-mips.org Cc: kvm@vger.kernel.org
2015-03-27MIPS: KVM: Add Config4/5 and writing of Config registersJames Hogan4-2/+126
Add Config4 and Config5 co-processor 0 registers, and add capability to write the Config1, Config3, Config4, and Config5 registers using the KVM API. Only supported bits can be written, to minimise the chances of the guest being given a configuration from e.g. QEMU that is inconsistent with that being emulated, and as such the handling is in trap_emul.c as it may need to be different for VZ. Currently the only modification permitted is to make Config4 and Config5 exist via the M bits, but other bits will be added for FPU and MSA support in future patches. Care should be taken by userland not to change bits without fully handling the possible extra state that may then exist and which the guest may begin to use and depend on. Signed-off-by: James Hogan <james.hogan@imgtec.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Gleb Natapov <gleb@kernel.org> Cc: linux-mips@linux-mips.org Cc: kvm@vger.kernel.org
2015-03-27MIPS: KVM: Simplify default guest Config registersJames Hogan2-31/+9
Various semi-used definitions exist in kvm_host.h for the default guest config registers. Remove them and use the appropriate values directly when initialising the Config registers. Signed-off-by: James Hogan <james.hogan@imgtec.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Gleb Natapov <gleb@kernel.org> Cc: linux-mips@linux-mips.org Cc: kvm@vger.kernel.org
2015-03-27MIPS: KVM: Clean up register definitions a littleJames Hogan2-55/+68
Clean up KVM_GET_ONE_REG / KVM_SET_ONE_REG register definitions for MIPS, to prepare for adding a new group for FPU & MSA vector registers. Definitions are added for common bits in each group of registers, e.g. KVM_REG_MIPS_CP0 = KVM_REG_MIPS | 0x10000, for the coprocessor 0 registers. Signed-off-by: James Hogan <james.hogan@imgtec.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Gleb Natapov <gleb@kernel.org> Cc: linux-mips@linux-mips.org Cc: kvm@vger.kernel.org
2015-03-27MIPS: KVM: Drop pr_info messages on init/exitJames Hogan1-3/+0
The information messages when the KVM module is loaded and unloaded are a bit pointless and out of line with other architectures, so lets drop them. Signed-off-by: James Hogan <james.hogan@imgtec.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Gleb Natapov <gleb@kernel.org> Cc: linux-mips@linux-mips.org Cc: kvm@vger.kernel.org
2015-03-27MIPS: KVM: Sort kvm_mips_get_reg() registersJames Hogan1-3/+3
Sort the registers in the kvm_mips_get_reg() switch by register number, which puts ERROREPC after the CONFIG registers. Signed-off-by: James Hogan <james.hogan@imgtec.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Gleb Natapov <gleb@kernel.org> Cc: linux-mips@linux-mips.org Cc: kvm@vger.kernel.org
2015-03-27MIPS: KVM: Implement PRid CP0 register accessJames Hogan2-0/+8
Implement access to the guest Processor Identification CP0 register using the KVM_GET_ONE_REG and KVM_SET_ONE_REG ioctls. This allows the owning process to modify and read back the value that is exposed to the guest in this register. Signed-off-by: James Hogan <james.hogan@imgtec.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Gleb Natapov <gleb@kernel.org> Cc: linux-mips@linux-mips.org Cc: kvm@vger.kernel.org
2015-03-27MIPS: KVM: Handle TRAP exceptions from guest kernelJames Hogan5-0/+71
Trap instructions are used by Linux to implement BUG_ON(), however KVM doesn't pass trap exceptions on to the guest if they occur in guest kernel mode, instead triggering an internal error "Exception Code: 13, not yet handled". The guest kernel then doesn't get a chance to print the usual BUG message and stack trace. Implement handling of the trap exception so that it gets passed to the guest and the user is left with a more useful log message. Signed-off-by: James Hogan <james.hogan@imgtec.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Gleb Natapov <gleb@kernel.org> Cc: kvm@vger.kernel.org Cc: linux-mips@linux-mips.org
2015-03-27MIPS: Clear [MSA]FPE CSR.Cause after notify_die()James Hogan3-12/+21
When handling floating point exceptions (FPEs) and MSA FPEs the Cause bits of the appropriate control and status register (FCSR for FPEs and MSACSR for MSA FPEs) are read and cleared before enabling interrupts, presumably so that it doesn't have to go through the pain of restoring those bits if the process is pre-empted, since writing those bits would cause another immediate exception while still in the kernel. The bits aren't normally ever restored again, since userland never expects to see them set. However for virtualisation it is necessary for the kernel to be able to restore these Cause bits, as the guest may have been interrupted in an FP exception handler but before it could read the Cause bits. This can be done by registering a die notifier, to get notified of the exception when such a value is restored, and if the PC was at the instruction which is used to restore the guest state, the handler can step over it and continue execution. The Cause bits can then remain set without causing further exceptions. For this to work safely a few changes are made: - __build_clear_fpe and __build_clear_msa_fpe no longer clear the Cause bits, and now return from exception level with interrupts disabled instead of enabled. - do_fpe() now clears the Cause bits and enables interrupts after notify_die() is called, so that the notifier can chose to return from exception without this happening. - do_msa_fpe() acts similarly, but now actually makes use of the second argument (msacsr) and calls notify_die() with the new DIE_MSAFP, allowing die notifiers to be informed of MSA FPEs too. Signed-off-by: James Hogan <james.hogan@imgtec.com> Acked-by: Ralf Baechle <ralf@linux-mips.org> Cc: Paul Burton <paul.burton@imgtec.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Gleb Natapov <gleb@kernel.org> Cc: linux-mips@linux-mips.org Cc: kvm@vger.kernel.org
2015-03-27MIPS: KVM: Handle MSA Disabled exceptions from guestJames Hogan4-0/+35
Guest user mode can generate a guest MSA Disabled exception on an MSA capable core by simply trying to execute an MSA instruction. Since this exception is unknown to KVM it will be passed on to the guest kernel. However guest Linux kernels prior to v3.15 do not set up an exception handler for the MSA Disabled exception as they don't support any MSA capable cores. This results in a guest OS panic. Since an older processor ID may be being emulated, and MSA support is not advertised to the guest, the correct behaviour is to generate a Reserved Instruction exception in the guest kernel so it can send the guest process an illegal instruction signal (SIGILL), as would happen with a non-MSA-capable core. Fix this as minimally as reasonably possible by preventing kvm_mips_check_privilege() from relaying MSA Disabled exceptions from guest user mode to the guest kernel, and handling the MSA Disabled exception by emulating a Reserved Instruction exception in the guest, via a new handle_msa_disabled() KVM callback. Signed-off-by: James Hogan <james.hogan@imgtec.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Paul Burton <paul.burton@imgtec.com> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Gleb Natapov <gleb@kernel.org> Cc: linux-mips@linux-mips.org Cc: kvm@vger.kernel.org Cc: <stable@vger.kernel.org> # v3.15+
2015-03-27MIPS: MSA: Fix big-endian FPR_IDX implementationJames Hogan1-1/+1
The maximum word size is 64-bits since MSA state is saved using st.d which stores two 64-bit words, therefore reimplement FPR_IDX using xor, and only within each 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/9169/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2015-03-27Revert "MIPS: Don't assume 64-bit FP registers for context switch"James Hogan3-194/+128
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>
2015-03-27MIPS: disable FPU if the mode is unsupportedPaul Burton1-7/+12
The expected semantics of __enable_fpu are for the FPU to be enabled in the given mode if possible, otherwise for the FPU to be left disabled and SIGFPE returned. The FPU was incorrectly being left enabled in cases where the desired value for FR was unavailable. Without ensuring the FPU is disabled in this case, it would be possible for userland to go on to execute further FP instructions natively in the incorrect mode, rather than those instructions being trapped & emulated as they need to be. Signed-off-by: Paul Burton <paul.burton@imgtec.com> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/9167/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2015-03-27MIPS: prevent FP context set via ptrace being discardedPaul Burton1-6/+24
If a ptracee has not used the FPU and the ptracer sets its FP context using PTRACE_POKEUSR, PTRACE_SETFPREGS or PTRACE_SETREGSET then that context will be discarded upon either the ptracee using the FPU or a further write to the context via ptrace. Prevent this loss by recording that the task has "used" math once its FP context has been written to. The context initialisation code that was present for the PTRACE_POKEUSR case is reused for the other 2 cases to provide consistent behaviour for the different ptrace requests. Signed-off-by: Paul Burton <paul.burton@imgtec.com> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/9166/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2015-03-27MIPS: Ensure FCSR cause bits are clear after invoking FPU emulatorPaul Burton1-8/+9
When running the emulator to handle an instruction that raised an FP unimplemented operation exception, the FCSR cause bits were being cleared. This is done to ensure that the kernel does not take an FP exception when later restoring FP context to registers. However, this was not being done when the emulator is invoked in response to a coprocessor unusable exception. This happens in 2 cases: - There is no FPU present in the system. In this case things were OK, since the FP context is never restored to hardware registers and thus no FP exception may be raised when restoring FCSR. - The FPU could not be configured to the mode required by the task. In this case it would be possible for the emulator to set cause bits which are later restored to hardware if the task migrates to a CPU whose associated FPU does support its mode requirements, or if the tasks FP mode requirements change. Consistently clear the cause bits after invoking the emulator, by moving the clearing to process_fpemu_return and ensuring this is always called before the tasks FP context is restored. This will make it easier to catch further paths invoking the emulator in future, as will be introduced in further patches. Signed-off-by: Paul Burton <paul.burton@imgtec.com> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/9165/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2015-03-27MIPS: clear MSACSR cause bits when handling MSA FP exceptionPaul Burton1-1/+10
Much like for traditional scalar FP exceptions, the cause bits in the MSACSR register need to be cleared following an MSA FP exception. Without doing so the exception will simply be raised again whenever the kernel restores MSACSR from a tasks saved context, leading to undesirable spurious exceptions. Clear the cause bits from the handle_msa_fpe function, mirroring the way handle_fpe clears the cause bits in FCSR. Signed-off-by: Paul Burton <paul.burton@imgtec.com> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/9164/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2015-03-27MIPS: wrap cfcmsa & ctcmsa accesses for toolchains with MSA supportPaul Burton1-4/+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>
2015-03-27MIPS: remove MSA macro recursionPaul Burton1-3/+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>
2015-03-27MIPS: assume at as source/dest of MSA copy/insert instructionsPaul Burton1-16/+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>
2015-03-27MIPS: Push .set mips64r* into the functions needing itPaul Burton2-9/+5
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>
2015-03-27MIPS: lose_fpu(): Disable FPU when MSA enabledJames Hogan1-0/+1
The lose_fpu() function only disables the FPU in CP0_Status.CU1 if the FPU is in use and MSA isn't enabled. This isn't necessarily a problem because KSTK_STATUS(current), the version of CP0_Status stored on the kernel stack on entry from user mode, does always get updated and gets restored when returning to user mode, but I don't think it was intended, and it is inconsistent with the case of only the FPU being in use. Sometimes leaving the FPU enabled may also mask kernel bugs where FPU operations are executed when the FPU might not be enabled. So lets disable the FPU in the MSA case too. Fixes: 33c771ba5c5d ("MIPS: save/disable MSA in lose_fpu") Signed-off-by: James Hogan <james.hogan@imgtec.com> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Paul Burton <paul.burton@imgtec.com> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/9323/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2015-03-02KVM: MIPS: Enable after disabling interruptTapasweni Pathak1-0/+1
Enable disabled interrupt, on unsuccessful operation. Found by Coccinelle. Signed-off-by: Tapasweni Pathak <tapaswenipathak@gmail.com> Acked-by: Julia Lawall <julia.lawall@lip6.fr> Reviewed-by: James Hogan <james.hogan@imgtec.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2015-03-02KVM: MIPS: Fix trace event to save PC directlyJames Hogan1-3/+3
Currently the guest exit trace event saves the VCPU pointer to the structure, and the guest PC is retrieved by dereferencing it when the event is printed rather than directly from the trace record. This isn't safe as the printing may occur long afterwards, after the PC has changed and potentially after the VCPU has been freed. Usually this results in the same (wrong) PC being printed for multiple trace events. It also isn't portable as userland has no way to access the VCPU data structure when interpreting the trace record itself. Lets save the actual PC in the structure so that the correct value is accessible later. Fixes: 669e846e6c4e ("KVM/MIPS32: MIPS arch specific APIs for KVM") Signed-off-by: James Hogan <james.hogan@imgtec.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Marcelo Tosatti <mtosatti@redhat.com> Cc: Gleb Natapov <gleb@kernel.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: linux-mips@linux-mips.org Cc: kvm@vger.kernel.org Cc: <stable@vger.kernel.org> # v3.10+ Acked-by: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2015-02-21Merge branch 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linusLinus Torvalds105-1123/+6390
Pull MIPS updates from Ralf Baechle: "This is the main pull request for MIPS: - a number of fixes that didn't make the 3.19 release. - a number of cleanups. - preliminary support for Cavium's Octeon 3 SOCs which feature up to 48 MIPS64 R3 cores with FPU and hardware virtualization. - support for MIPS R6 processors. Revision 6 of the MIPS architecture is a major revision of the MIPS architecture which does away with many of original sins of the architecture such as branch delay slots. This and other changes in R6 require major changes throughout the entire MIPS core architecture code and make up for the lion share of this pull request. - finally some preparatory work for eXtendend Physical Address support, which allows support of up to 40 bit of physical address space on 32 bit processors" [ Ahh, MIPS can't leave the PAE brain damage alone. It's like every CPU architect has to make that mistake, but pee in the snow by changing the TLA. But whether it's called PAE, LPAE or XPA, it's horrid crud - Linus ] * 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus: (114 commits) MIPS: sead3: Corrected get_c0_perfcount_int MIPS: mm: Remove dead macro definitions MIPS: OCTEON: irq: add CIB and other fixes MIPS: OCTEON: Don't do acknowledge operations for level triggered irqs. MIPS: OCTEON: More OCTEONIII support MIPS: OCTEON: Remove setting of processor specific CVMCTL icache bits. MIPS: OCTEON: Core-15169 Workaround and general CVMSEG cleanup. MIPS: OCTEON: Update octeon-model.h code for new SoCs. MIPS: OCTEON: Implement DCache errata workaround for all CN6XXX MIPS: OCTEON: Add little-endian support to asm/octeon/octeon.h MIPS: OCTEON: Implement the core-16057 workaround MIPS: OCTEON: Delete unused COP2 saving code MIPS: OCTEON: Use correct instruction to read 64-bit COP0 register MIPS: OCTEON: Save and restore CP2 SHA3 state MIPS: OCTEON: Fix FP context save. MIPS: OCTEON: Save/Restore wider multiply registers in OCTEON III CPUs MIPS: boot: Provide more uImage options MIPS: Remove unneeded #ifdef __KERNEL__ from asm/processor.h MIPS: ip22-gio: Remove legacy suspend/resume support mips: pci: Add ifdef around pci_proc_domain ...
2015-02-21Merge tag 'clk-for-linus-3.20' of git://git.linaro.org/people/mike.turquette/linuxLinus Torvalds1-0/+6
Pull clock framework updates from Mike Turquette: "The clock framework changes contain the usual driver additions, enhancements and fixes mostly for ARM32, ARM64, MIPS and Power-based devices. Additionally the framework core underwent a bit of surgery with two major changes: - The boundary between the clock core and clock providers (e.g clock drivers) is now more well defined with dedicated provider helper functions. struct clk no longer maps 1:1 with the hardware clock but is a true per-user cookie which helps us tracker users of hardware clocks and debug bad behavior. - The addition of rate constraints for clocks. Rate ranges are now supported which are analogous to the voltage ranges in the regulator framework. Unfortunately these changes to the core created some breakeage. We think we fixed it all up but for this reason there are lots of last minute commits trying to undo the damage" * tag 'clk-for-linus-3.20' of git://git.linaro.org/people/mike.turquette/linux: (113 commits) clk: Only recalculate the rate if needed Revert "clk: mxs: Fix invalid 32-bit access to frac registers" clk: qoriq: Add support for the platform PLL powerpc/corenet: Enable CLK_QORIQ clk: Replace explicit clk assignment with __clk_hw_set_clk clk: Add __clk_hw_set_clk helper function clk: Don't dereference parent clock if is NULL MIPS: Alchemy: Remove bogus args from alchemy_clk_fgcs_detr clkdev: Always allocate a struct clk and call __clk_get() w/ CCF clk: shmobile: div6: Avoid division by zero in .round_rate() clk: mxs: Fix invalid 32-bit access to frac registers clk: omap: compile legacy omap3 clocks conditionally clkdev: Export clk_register_clkdev clk: Add rate constraints to clocks clk: remove clk-private.h pci: xgene: do not use clk-private.h arm: omap2+ remove dead clock code clk: Make clk API return per-user struct clk instances clk: tegra: Define PLLD_DSI and remove dsia(b)_mux clk: tegra: Add support for the Tegra132 CAR IP block ...
2015-02-20MIPS: sead3: Corrected get_c0_perfcount_intNiklas Cassel1-1/+1
Commit e9de688dac65 ("irqchip: mips-gic: Support local interrupts") updated several platforms. This is a copy paste error. Signed-off-by: Niklas Cassel <niklass@axis.com> Reviewed-by: Andrew Bresticker <abrestic@chromium.org> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/9245/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2015-02-20MIPS: mm: Remove dead macro definitionsAndreas Ruprecht2-16/+0
In commit c441d4a54c6e ("MIPS: mm: Only build one microassembler that is suitable"), the Makefile at arch/mips/mm was rewritten to only build the "right" microassembler file, depending on whether CONFIG_CPU_MICROMIPS is set or not. In the files, however, there are still preprocessor definitions depending on CONFIG_CPU_MICROMIPS. The #ifdef around them can now never evaluate to true, so let's remove them altogether. This inconsistency was found using the undertaker-checkpatch tool. Signed-off-by: Andreas Ruprecht <rupran@einserver.de> Reviewed-by: Maciej W. Rozycki <macro@linux-mips.org> Cc: linux-mips@linux-mips.org Cc: linux-kernel@vger.kernel.org Cc: Valentin Rothberg <valentinrothberg@gmail.com> Cc: Paul Bolle <pebolle@tiscali.nl> Patchwork: https://patchwork.linux-mips.org/patch/9267/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2015-02-20MIPS: OCTEON: irq: add CIB and other fixesDavid Daney1-269/+780
- Use of_irq_init() to initialize interrupt controllers - Get rid of some unlikely() - Add CIB to support SATA and other interrupts - Add support for CIU SUM2 interrupt sources Signed-off-by: David Daney <david.daney@cavium.com> Signed-off-by: Leonid Rosenboim <lrosenboim@caviumnetworks.com> Signed-off-by: Aleksey Makarov <aleksey.makarov@auriga.com> Signed-off-by: Peter Swain <peter.swain@cavium.com> Cc: linux-mips@linux-mips.org Cc: linux-kernel@vger.kernel.org Cc: Rob Herring <robh+dt@kernel.org> Cc: Pawel Moll <pawel.moll@arm.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Ian Campbell <ijc+devicetree@hellion.org.uk> Cc: Kumar Gala <galak@codeaurora.org> Cc: devicetree@vger.kernel.org Patchwork: https://patchwork.linux-mips.org/patch/8947/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2015-02-20MIPS: OCTEON: Don't do acknowledge operations for level triggered irqs.David Daney1-2/+43
The acknowledge bits don't exist for level triggered irqs, so setting them causes the simulator to terminate. Signed-off-by: David Daney <david.daney@cavium.com> Signed-off-by: Leonid Rosenboim <lrosenboim@caviumnetworks.com> Signed-off-by: Aleksey Makarov <aleksey.makarov@auriga.com> Cc: linux-mips@linux-mips.org Cc: linux-kernel@vger.kernel.org Patchwork: https://patchwork.linux-mips.org/patch/8946/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2015-02-20MIPS: OCTEON: More OCTEONIII supportChandrakala Chavva4-2/+326
Read clock rate from the correct CSR. Don't clear COP0_DCACHE for OCTEONIII. Signed-off-by: Chandrakala Chavva <cchavva@caviumnetworks.com> Signed-off-by: Aleksey Makarov <aleksey.makarov@auriga.com> Signed-off-by: David Daney <david.daney@cavium.com> Cc: linux-mips@linux-mips.org Cc: linux-kernel@vger.kernel.org Patchwork: https://patchwork.linux-mips.org/patch/8945/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2015-02-20MIPS: OCTEON: Remove setting of processor specific CVMCTL icache bits.Chad Reese1-20/+0
CN38XX pass 1 required icache prefetching to be turned off. This chip never reached production and is long dead. Other processor specific icache settings are done by the bootloader. Remove these bits from the kernel. Signed-off-by: Chad Reese <kreese@caviumnetworks.com> Signed-off-by: Aleksey Makarov <aleksey.makarov@auriga.com> Cc: linux-mips@linux-mips.org Cc: linux-kernel@vger.kernel.org Cc: David Daney <david.daney@cavium.com> Patchwork: https://patchwork.linux-mips.org/patch/8944/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2015-02-20MIPS: OCTEON: Core-15169 Workaround and general CVMSEG cleanup.David Daney2-6/+17
Signed-off-by: David Daney <david.daney@cavium.com> Signed-off-by: Aleksey Makarov <aleksey.makarov@auriga.com> Cc: linux-mips@linux-mips.org Cc: linux-kernel@vger.kernel.org Patchwork: https://patchwork.linux-mips.org/patch/8943/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2015-02-20MIPS: OCTEON: Update octeon-model.h code for new SoCs.David Daney5-27/+90
Add coverage for OCTEON III models. Signed-off-by: David Daney <david.daney@cavium.com> Signed-off-by: Aleksey Makarov <aleksey.makarov@auriga.com> Cc: linux-mips@linux-mips.org Cc: linux-kernel@vger.kernel.org Patchwork: https://patchwork.linux-mips.org/patch/8942/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2015-02-20MIPS: OCTEON: Implement DCache errata workaround for all CN6XXXDavid Daney3-4/+8
Make messages refer to all CN6XXX. Signed-off-by: David Daney <david.daney@cavium.com> Signed-off-by: Aleksey Makarov <aleksey.makarov@auriga.com> Cc: linux-mips@linux-mips.org Cc: linux-kernel@vger.kernel.org Patchwork: https://patchwork.linux-mips.org/patch/8941/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2015-02-20MIPS: OCTEON: Add little-endian support to asm/octeon/octeon.hDavid Daney1-30/+105
Also update union octeon_cvmemctl with new OCTEON II fields. [aleksey.makarov@auriga.com: use __BITFIELD_FIELD] Signed-off-by: David Daney <david.daney@cavium.com> Signed-off-by: Aleksey Makarov <aleksey.makarov@auriga.com> Cc: linux-mips@linux-mips.org Cc: linux-kernel@vger.kernel.org Patchwork: https://patchwork.linux-mips.org/patch/8940/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2015-02-20MIPS: OCTEON: Implement the core-16057 workaroundDavid Daney1-0/+22
Disable ICache prefetch for certian Octeon II processors. Signed-off-by: David Daney <david.daney@cavium.com> Signed-off-by: Aleksey Makarov <aleksey.makarov@auriga.com> Cc: linux-mips@linux-mips.org Cc: linux-kernel@vger.kernel.org Patchwork: https://patchwork.linux-mips.org/patch/8938/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2015-02-20MIPS: OCTEON: Delete unused COP2 saving codeAleksey Makarov1-26/+0
Commit 2c952e06e4f5 ("MIPS: Move cop2 save/restore to switch_to()") removes assembler code to store COP2 registers. Commit a36d8225bceb ("MIPS: OCTEON: Enable use of FPU") mistakenly restores it Fixes: a36d8225bceb ("MIPS: OCTEON: Enable use of FPU") Signed-off-by: Aleksey Makarov <aleksey.makarov@auriga.com> Cc: linux-mips@linux-mips.org Cc: linux-kernel@vger.kernel.org Cc: David Daney <david.daney@cavium.com> Patchwork: https://patchwork.linux-mips.org/patch/8937/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2015-02-20MIPS: OCTEON: Use correct instruction to read 64-bit COP0 registerChandrakala Chavva1-3/+3
Use dmfc0/dmtc0 instructions for reading CvmMemCtl COP0 register, its a 64-bit wide. Signed-off-by: Chandrakala Chavva <cchavva@caviumnetworks.com> Signed-off-by: Aleksey Makarov <aleksey.makarov@auriga.com> Cc: linux-mips@linux-mips.org Cc: linux-kernel@vger.kernel.org Cc: David Daney <david.daney@cavium.com> Patchwork: https://patchwork.linux-mips.org/patch/8936/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2015-02-20MIPS: OCTEON: Save and restore CP2 SHA3 stateDavid Daney3-11/+35
Allocate new save space, and then save/restore the registers if OCTEON III. Signed-off-by: David Daney <david.daney@cavium.com> Signed-off-by: Aleksey Makarov <aleksey.makarov@auriga.com> Cc: linux-mips@linux-mips.org Cc: linux-kernel@vger.kernel.org Patchwork: https://patchwork.linux-mips.org/patch/8935/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2015-02-20MIPS: OCTEON: Fix FP context save.David Daney1-12/+7
It wasn't being saved on task switch. Signed-off-by: David Daney <david.daney@cavium.com> Signed-off-by: Aleksey Makarov <aleksey.makarov@auriga.com> Cc: linux-mips@linux-mips.org Cc: linux-kernel@vger.kernel.org Patchwork: https://patchwork.linux-mips.org/patch/8934/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>