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2016-07-05MIPS: KVM: Dynamically choose scratch registersJames Hogan1-0/+1
Scratch cop0 registers are needed by KVM to be able to save/restore all the GPRs, including k0/k1, and for storing the VCPU pointer. However no registers are universally suitable for these purposes, so the decision should be made at runtime. Until now, we've used DDATA_LO to store the VCPU pointer, and ErrorEPC as a temporary. It could be argued that this is abuse of those registers, and DDATA_LO is known not to be usable on certain implementations (Cavium Octeon). If KScratch registers are present, use them instead. We save & restore the temporary register in addition to the VCPU pointer register when using a KScratch register for it, as it may be used for normal host TLB handling too. Signed-off-by: James Hogan <james.hogan@imgtec.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Radim KrÄmář <rkrcmar@redhat.com> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: linux-mips@linux-mips.org Cc: kvm@vger.kernel.org Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-07-05MIPS; KVM: Convert exception entry to uasmJames Hogan1-2/+6
Convert the whole of locore.S (assembly to enter guest and handle exception entry) to be generated dynamically with uasm. This is done with minimal changes to the resulting code. The main changes are: - Some constants are generated by uasm using LUI+ADDIU instead of LUI+ORI. - Loading of lo and hi are swapped around in vcpu_run but not when resuming the guest after an exit. Both bits of logic are now generated by the same code. - Register MOVEs in uasm use different ADDU operand ordering to GNU as, putting zero register into rs instead of rt. - The JALR.HB to call the C exit handler is switched to JALR, since the hazard barrier would appear to be unnecessary. This will allow further optimisation in the future to dynamically handle the capabilities of the CPU. Signed-off-by: James Hogan <james.hogan@imgtec.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Radim KrÄmář <rkrcmar@redhat.com> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: linux-mips@linux-mips.org Cc: kvm@vger.kernel.org Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-07-05MIPS: uasm: Add MTHI/MTLO instructionsJames Hogan1-0/+2
Add MTHI/MTLO instructions for writing to the hi & lo registers to uasm so that KVM can use uasm for generating its entry point code at runtime. 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: uasm: Add DI instructionJames Hogan1-0/+1
Add DI instruction for disabling interrupts to uasm so that KVM can use uasm for generating its entry point code at runtime. 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: uasm: Add CFCMSA/CTCMSA instructionsJames Hogan1-0/+2
Add CFCMSA/CTCMSA instructions for accessing MSA control registers to uasm so that KVM can use uasm for generating its entry point code at runtime. 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: uasm: Add CFC1/CTC1 instructionsJames Hogan1-0/+2
Add CFC1/CTC1 instructions for accessing FP control registers to uasm so that KVM can use uasm for generating its entry point code at runtime. 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>
2016-07-02MIPS: Fix possible corruption of cache mode by mprotect.Ralf Baechle1-4/+6
The following testcase may result in a page table entries with a invalid CCA field being generated: static void *bindstack; static int sysrqfd; static void protect_low(int protect) { mprotect(bindstack, BINDSTACK_SIZE, protect); } static void sigbus_handler(int signal, siginfo_t * info, void *context) { void *addr = info->si_addr; write(sysrqfd, "x", 1); printf("sigbus, fault address %p (should not happen, but might)\n", addr); abort(); } static void run_bind_test(void) { unsigned int *p = bindstack; p[0] = 0xf001f001; write(sysrqfd, "x", 1); /* Set trap on access to p[0] */ protect_low(PROT_NONE); write(sysrqfd, "x", 1); /* Clear trap on access to p[0] */ protect_low(PROT_READ | PROT_WRITE | PROT_EXEC); write(sysrqfd, "x", 1); /* Check the contents of p[0] */ if (p[0] != 0xf001f001) { write(sysrqfd, "x", 1); /* Reached, but shouldn't be */ printf("badness, shouldn't happen but does\n"); abort(); } } int main(void) { struct sigaction sa; sysrqfd = open("/proc/sysrq-trigger", O_WRONLY); if (sigprocmask(SIG_BLOCK, NULL, &sa.sa_mask)) { perror("sigprocmask"); return 0; } sa.sa_sigaction = sigbus_handler; sa.sa_flags = SA_SIGINFO | SA_NODEFER | SA_RESTART; if (sigaction(SIGBUS, &sa, NULL)) { perror("sigaction"); return 0; } bindstack = mmap(NULL, BINDSTACK_SIZE, PROT_READ | PROT_WRITE | PROT_EXEC, MAP_PRIVATE | MAP_ANONYMOUS, -1, 0); if (bindstack == MAP_FAILED) { perror("mmap bindstack"); return 0; } printf("bindstack: %p\n", bindstack); run_bind_test(); printf("done\n"); return 0; } There are multiple ingredients for this: 1) PAGE_NONE is defined to _CACHE_CACHABLE_NONCOHERENT, which is CCA 3 on all platforms except SB1 where it's CCA 5. 2) _page_cachable_default must have bits set which are not set _CACHE_CACHABLE_NONCOHERENT. 3) Either the defective version of pte_modify for XPA or the standard version must be in used. However pte_modify for the 36 bit address space support is no affected. In that case additional bits in the final CCA mode may generate an invalid value for the CCA field. On the R10000 system where this was tracked down for example a CCA 7 has been observed, which is Uncached Accelerated. Fixed by: 1) Using the proper CCA mode for PAGE_NONE just like for all the other PAGE_* pte/pmd bits. 2) Fix the two affected variants of pte_modify. Further code inspection also shows the same issue to exist in pmd_modify which would affect huge page systems. Issue in pte_modify tracked down by Alastair Bridgewater, PAGE_NONE and pmd_modify issue found by me. The history of this goes back beyond Linus' git history. Chris Dearman's commit 351336929ccf222ae38ff0cb7a8dd5fd5c6236a0 ("[MIPS] Allow setting of the cache attribute at run time.") missed the opportunity to fix this but it was originally introduced in lmo commit d523832cf12007b3242e50bb77d0c9e63e0b6518 ("Missing from last commit.") and 32cc38229ac7538f2346918a09e75413e8861f87 ("New configuration option CONFIG_MIPS_UNCACHED.") Signed-off-by: Ralf Baechle <ralf@linux-mips.org> Reported-by: Alastair Bridgewater <alastair.bridgewater@gmail.com>
2016-06-25mips: get rid of superfluous __GFP_REPEATMichal Hocko1-3/+3
__GFP_REPEAT has a rather weak semantic but since it has been introduced around 2.6.12 it has been ignored for low order allocations. pte_alloc_one{_kernel}, pmd_alloc_one allocate PTE_ORDER resp. PMD_ORDER but both are not larger than 1. This means that this flag has never been actually useful here because it has always been used only for PAGE_ALLOC_COSTLY requests. Link: http://lkml.kernel.org/r/1464599699-30131-8-git-send-email-mhocko@kernel.org Signed-off-by: Michal Hocko <mhocko@suse.com> Cc: John Crispin <blogic@openwrt.org> Cc: Ralf Baechle <ralf@linux-mips.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-06-17PCI: Unify pci_resource_to_user() declarationsBjorn Helgaas1-10/+0
Replace the pci_resource_to_user() declarations in each arch that defines HAVE_ARCH_PCI_RESOURCE_TO_USER with a single one in linux/pci.h. Change the MIPS static inline implementation to a non-inline version so the static inline doesn't conflict with the new non-static linux/pci.h declaration. No functional change intended. Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2016-06-16locking/atomic, arch/mips: Convert to _relaxed atomicsPeter Zijlstra1-20/+22
Generic code will construct {,_acquire,_release} versions by adding the required smp_mb__{before,after}_atomic() calls. XXX if/when MIPS will start using their new SYNCxx instructions they can provide custom __atomic_op_{acquire,release}() macros as per the powerpc example. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-arch@vger.kernel.org Cc: linux-kernel@vger.kernel.org Cc: linux-mips@linux-mips.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-06-16locking/atomic: Remove linux/atomic.h:atomic_fetch_or()Peter Zijlstra1-2/+0
Since all architectures have this implemented now natively, remove this dead code. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-arch@vger.kernel.org Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-06-16locking/atomic, arch/mips: Implement atomic{,64}_fetch_{add,sub,and,or,xor}()Peter Zijlstra1-9/+129
Implement FETCH-OP atomic primitives, these are very similar to the existing OP-RETURN primitives we already have, except they return the value of the atomic variable _before_ modification. This is especially useful for irreversible operations -- such as bitops (because it becomes impossible to reconstruct the state prior to modification). Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-arch@vger.kernel.org Cc: linux-kernel@vger.kernel.org Cc: linux-mips@linux-mips.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-06-16MIPS: KVM: Use mipsregs.h defs for config registersJames Hogan1-67/+0
Convert MIPS KVM guest register state initialisation to use the standard <asm/mipsregs.h> register field definitions for Config registers, and drop the custom definitions in kvm_host.h which it was using before. Signed-off-by: James Hogan <james.hogan@imgtec.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Radim Krčmář <rkrcmar@redhat.com> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: linux-mips@linux-mips.org Cc: kvm@vger.kernel.org Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-06-16MIPS: Add define for Config.VI (virtual icache) bitJames Hogan1-0/+1
The Config.VI bit specifies that the instruction cache is virtually tagged, which is checked in c-r4k.c's probe_pcache(). Add a proper definition for it in mipsregs.h and make use of it. 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>
2016-06-16MIPS: KVM: Move commpage so 0x0 is unmappedJames Hogan1-2/+8
The comm page which is mapped into the guest kernel address space at 0x0 has the unfortunate side effect of allowing guest kernel NULL pointer dereferences to succeed. The only constraint on this address is that it must be within 32KiB of 0x0, so that single lw/sw instructions (which have 16-bit signed offset fields) can be used to access it, using the zero register as a base. So lets move the comm page as high as possible within that constraint so that 0x0 can be left unmapped, at least for page sizes < 32KiB. Signed-off-by: James Hogan <james.hogan@imgtec.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Radim Krčmář <rkrcmar@redhat.com> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: linux-mips@linux-mips.org Cc: kvm@vger.kernel.org Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-06-16MIPS: KVM: Add KScratch registersJames Hogan1-0/+19
Allow up to 6 KVM guest KScratch registers to be enabled and accessed via the KVM guest register API and from the guest itself (the fallback reading and writing of commpage registers is sufficient for KScratch registers to work as expected). User mode can expose the registers by setting the appropriate bits of the guest Config4.KScrExist field. KScratch registers that aren't usable won't be writeable via the KVM Ioctl API. Signed-off-by: James Hogan <james.hogan@imgtec.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Radim Krčmář <rkrcmar@redhat.com> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: linux-mips@linux-mips.org Cc: kvm@vger.kernel.org Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-06-16MIPS: KVM: Don't hardcode restored HWREnaJames Hogan1-0/+1
KVM modifies CP0_HWREna during guest execution so it can trap and emulate RDHWR instructions, however it always restores the hardcoded value 0x2000000F. This assumes the presence of the UserLocal register, and the absence of any implementation dependent or future HW registers. Fix by exporting the value that traps.c write into CP0_HWREna, and loading from there instead of hard coding. Signed-off-by: James Hogan <james.hogan@imgtec.com> Acked-by: Ralf Baechle <ralf@linux-mips.org> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Radim Krčmář <rkrcmar@redhat.com> Cc: linux-mips@linux-mips.org Cc: kvm@vger.kernel.org Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-06-16MIPS: Clean up RDHWR handlingJames Hogan2-2/+20
No preprocessor definitions are used in the handling of the registers accessible with the RDHWR instruction, nor the corresponding bits in the CP0 HWREna register. Add definitions for both the register numbers (MIPS_HWR_*) and HWREna bits (MIPS_HWRENA_*) in asm/mipsregs.h and make use of them in the initialisation of HWREna and emulation of the RDHWR instruction. Signed-off-by: James Hogan <james.hogan@imgtec.com> Acked-by: Ralf Baechle <ralf@linux-mips.org> Cc: David Daney <david.daney@cavium.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Radim Krčmář <rkrcmar@redhat.com> Cc: linux-mips@linux-mips.org Cc: kvm@vger.kernel.org Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-06-16MIPS: KVM: Use raw_cpu_has_fpu in kvm_mips_guest_can_have_fpu()James Hogan1-1/+1
We need to use kvm_mips_guest_can_have_fpu() when deciding which registers to list with KVM_GET_REG_LIST, however it causes warnings with preemption since it uses cpu_has_fpu. KVM is only really supported on CPUs which have symmetric FPUs, so switch to raw_cpu_has_fpu to avoid the warning. Signed-off-by: James Hogan <james.hogan@imgtec.com> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Radim Krčmář <rkrcmar@redhat.com> Cc: linux-mips@linux-mips.org Cc: kvm@vger.kernel.org Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-06-16MIPS: KVM: Make KVM_GET_REG_LIST dynamicJames Hogan1-0/+2
Make the implementation of KVM_GET_REG_LIST more dynamic so that only the subset of registers actually available can be exposed to user mode. This is important for VZ where some of the guest register state may not be possible to prevent the guest from accessing, therefore the user process may need to be aware of the state even if it doesn't understand what the state is for. This also allows different MIPS KVM implementations to provide different registers to one another, by way of new num_regs(vcpu) and copy_reg_indices(vcpu, indices) callback functions, currently just stubbed for trap & emulate. Signed-off-by: James Hogan <james.hogan@imgtec.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Radim Krčmář <rkrcmar@redhat.com> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: linux-mips@linux-mips.org Cc: kvm@vger.kernel.org Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-06-16MIPS: KVM: Convert emulation to use asm/inst.hJames Hogan1-9/+13
Convert various MIPS KVM guest instruction emulation functions to decode instructions (and encode translations) using the union mips_instruction and related enumerations in asm/inst.h rather than #defines and hardcoded values. Signed-off-by: James Hogan <james.hogan@imgtec.com> Acked-by: Ralf Baechle <ralf@linux-mips.org> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Radim Krčmář <rkrcmar@redhat.com> Cc: linux-mips@linux-mips.org Cc: kvm@vger.kernel.org Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-06-14locking/spinlock, arch: Update and fix spin_unlock_wait() implementationsPeter Zijlstra1-2/+17
This patch updates/fixes all spin_unlock_wait() implementations. The update is in semantics; where it previously was only a control dependency, we now upgrade to a full load-acquire to match the store-release from the spin_unlock() we waited on. This ensures that when spin_unlock_wait() returns, we're guaranteed to observe the full critical section we waited on. This fixes a number of spin_unlock_wait() users that (not unreasonably) rely on this. I also fixed a number of ticket lock versions to only wait on the current lock holder, instead of for a full unlock, as this is sufficient. Furthermore; again for ticket locks; I added an smp_rmb() in between the initial ticket load and the spin loop testing the current value because I could not convince myself the address dependency is sufficient, esp. if the loads are of different sizes. I'm more than happy to remove this smp_rmb() again if people are certain the address dependency does indeed work as expected. Note: PPC32 will be fixed independently Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: chris@zankel.net Cc: cmetcalf@mellanox.com Cc: davem@davemloft.net Cc: dhowells@redhat.com Cc: james.hogan@imgtec.com Cc: jejb@parisc-linux.org Cc: linux@armlinux.org.uk Cc: mpe@ellerman.id.au Cc: ralf@linux-mips.org Cc: realmz6@gmail.com Cc: rkuo@codeaurora.org Cc: rth@twiddle.net Cc: schwidefsky@de.ibm.com Cc: tony.luck@intel.com Cc: vgupta@synopsys.com Cc: ysato@users.sourceforge.jp Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-06-14MIPS: KVM: Clean up kvm_exit trace eventJames Hogan1-22/+0
Clean up the MIPS kvm_exit trace event so that the exit reasons are specified in a trace friendly way (via __print_symbolic), and so that the exit reasons that derive straight from Cause.ExcCode values map directly, allowing a single trace_kvm_exit() call to replace a bunch of individual ones. Signed-off-by: James Hogan <james.hogan@imgtec.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Radim Krčmář <rkrcmar@redhat.com> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: kvm@vger.kernel.org Cc: linux-mips@linux-mips.org Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-06-14MIPS: KVM: Generalise fpu_inuse for other stateJames Hogan1-4/+4
Rename fpu_inuse and the related definitions to aux_inuse so it can be used for lazy context management of other auxiliary processor state too, such as VZ guest timer, watchpoints and performance counters. Signed-off-by: James Hogan <james.hogan@imgtec.com> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Radim Krčmář <rkrcmar@redhat.com> Cc: linux-mips@linux-mips.org Cc: kvm@vger.kernel.org Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-06-14MIPS: KVM: Use MIPS_ENTRYLO_* defs from mipsregs.hJames Hogan1-7/+4
Convert KVM to use the MIPS_ENTRYLO_* definitions from <asm/mipsregs.h> rather than custom definitions in kvm_host.h Signed-off-by: James Hogan <james.hogan@imgtec.com> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Radim Krčmář <rkrcmar@redhat.com> Cc: linux-mips@linux-mips.org Cc: kvm@vger.kernel.org Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-06-14MIPS: KVM: Simplify TLB_* macrosJames Hogan1-5/+3
Simplify some of the TLB_ macros making use of the arrayification of tlb_lo. Basically we index the array by the bit of the virtual address which determines whether the even or odd entry is used, instead of having a conditional. Signed-off-by: James Hogan <james.hogan@imgtec.com> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Radim Krčmář <rkrcmar@redhat.com> Cc: linux-mips@linux-mips.org Cc: kvm@vger.kernel.org Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-06-14MIPS: KVM: Arrayify struct kvm_mips_tlb::tlb_lo*James Hogan1-6/+5
The values of the EntryLo0 and EntryLo1 registers for a TLB entry are stored in separate members of struct kvm_mips_tlb called tlb_lo0 and tlb_lo1 respectively. To allow future code which needs to manipulate arbitrary EntryLo data in the TLB entry to be simpler and less conditional, replace these members with an array of two elements. Signed-off-by: James Hogan <james.hogan@imgtec.com> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Radim Krčmář <rkrcmar@redhat.com> Cc: linux-mips@linux-mips.org Cc: kvm@vger.kernel.org Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-06-14MIPS: KVM: Restore host EBase from ebase variableJames Hogan1-1/+1
The host kernel's exception vector base address is currently saved in the VCPU structure at creation time, and restored on a guest exit. However it doesn't change and can already be easily accessed from the 'ebase' variable (arch/mips/kernel/traps.c), so drop the host_ebase member of kvm_vcpu_arch, export the 'ebase' variable to modules and load from there instead. This does result in a single extra instruction (lui) on the guest exit path, but simplifies the code a bit and removes the redundant storage of the host exception base address. Credit for the idea goes to Cavium's VZ KVM implementation. Signed-off-by: James Hogan <james.hogan@imgtec.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Radim Krčmář <rkrcmar@redhat.com> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: linux-mips@linux-mips.org Cc: kvm@vger.kernel.org Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-06-14MIPS: KVM: Drop unused hpa0/hpa1 args from functionJames Hogan1-3/+1
The function kvm_mips_handle_mapped_seg_tlb_fault() has two completely unused pointer arguments, hpa0 and hpa1, for which all users always pass NULL. Drop these two arguments and update the callers. Signed-off-by: James Hogan <james.hogan@imgtec.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Radim Krčmář <rkrcmar@redhat.com> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: linux-mips@linux-mips.org Cc: kvm@vger.kernel.org Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-06-14MIPS: KVM: Don't indirect KVM functionsJames Hogan1-3/+0
Several KVM module functions are indirected so that they can be accessed from tlb.c which is statically built into the kernel. This is no longer necessary as the relevant bits of code have moved into mmu.c which is part of the KVM module, so drop the indirections. Note: is_error_pfn() is defined inline in kvm_host.h, so didn't actually require the KVM module to be loaded for it to work anyway. Signed-off-by: James Hogan <james.hogan@imgtec.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Radim Krčmář <rkrcmar@redhat.com> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: linux-mips@linux-mips.org Cc: kvm@vger.kernel.org Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-06-14MIPS: KVM: Move non-TLB handling code out of tlb.cJames Hogan1-0/+4
Various functions in tlb.c perform higher level MMU handling, but don't strictly need to be statically built into the kernel as they don't directly manipulate TLB entries. Move these functions out into a separate mmu.c which will be built into the KVM kernel module. This allows them to directly reference KVM functions in the KVM kernel module in future. Module exports of these functions have been removed, since they aren't needed outside of KVM. Signed-off-by: James Hogan <james.hogan@imgtec.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Radim Krčmář <rkrcmar@redhat.com> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: linux-mips@linux-mips.org Cc: kvm@vger.kernel.org Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-06-14MIPS: KVM: Make various Cause variables 32-bitJames Hogan1-20/+20
The CP0 Cause register is passed around in KVM quite a bit, often as an unsigned long, even though it is always 32-bits long. Resize it to u32 throughout MIPS KVM. Signed-off-by: James Hogan <james.hogan@imgtec.com> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Radim Krčmář <rkrcmar@redhat.com> Cc: linux-mips@linux-mips.org Cc: kvm@vger.kernel.org Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-06-14MIPS: KVM: Convert headers to kernel sized typesJames Hogan1-50/+47
Convert the MIPS kvm_host.h structs, function declaration prototypes and associated definition prototypes to use standard kernel sized types (e.g. u32) instead of inttypes.h style ones (e.g. uint32_t). Signed-off-by: James Hogan <james.hogan@imgtec.com> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Radim Krčmář <rkrcmar@redhat.com> Cc: linux-mips@linux-mips.org Cc: kvm@vger.kernel.org Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-06-14MIPS: KVM: Drop unused host_cp0_entryhiJames Hogan1-1/+0
The host EntryHi in the KVM VCPU context is virtually unused. It gets stored on exceptions, but only ever used in a kvm_debug() when a TLB miss occurs. Drop it entirely, removing that information from the kvm_debug output. Signed-off-by: James Hogan <james.hogan@imgtec.com> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Radim Krčmář <rkrcmar@redhat.com> Cc: linux-mips@linux-mips.org Cc: kvm@vger.kernel.org Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-06-14MIPS: KVM: Drop unused guest_inst from kvm_vcpu_archJames Hogan1-1/+0
The MIPS kvm_vcpu_arch::guest_inst isn't used, so drop it from the struct and drop its asm-offsets definition. Signed-off-by: James Hogan <james.hogan@imgtec.com> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Radim Krčmář <rkrcmar@redhat.com> Cc: linux-mips@linux-mips.org Cc: kvm@vger.kernel.org Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-06-14MIPS: KVM: Include bit 31 in segment matchesJames Hogan1-1/+1
When faulting guest addresses are matched against guest segments with the KVM_GUEST_KSEGX() macro, change the mask to 0xe0000000 so as to include bit 31. This is mainly for safety's sake, as it prevents a rogue BadVAddr in the host kseg2/kseg3 segments (e.g. 0xC*******) after a TLB exception from matching the guest kseg0 segment (e.g. 0x4*******), triggering an internal KVM error instead of allowing the corresponding guest kseg0 page to be mapped into the host vmalloc space. Such a rogue BadVAddr was observed to happen with the host MIPS kernel running under QEMU with KVM built as a module, due to a not entirely transparent optimisation in the QEMU TLB handling. This has already been worked around properly in a previous commit. Signed-off-by: James Hogan <james.hogan@imgtec.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Radim Krčmář <rkrcmar@redhat.com> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: kvm@vger.kernel.org Cc: linux-mips@linux-mips.org Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-06-14MIPS: KVM: Fix modular KVM under QEMUJames Hogan1-0/+1
Copy __kvm_mips_vcpu_run() into unmapped memory, so that we can never get a TLB refill exception in it when KVM is built as a module. This was observed to happen with the host MIPS kernel running under QEMU, due to a not entirely transparent optimisation in the QEMU TLB handling where TLB entries replaced with TLBWR are copied to a separate part of the TLB array. Code in those pages continue to be executable, but those mappings persist only until the next ASID switch, even if they are marked global. An ASID switch happens in __kvm_mips_vcpu_run() at exception level after switching to the guest exception base. Subsequent TLB mapped kernel instructions just prior to switching to the guest trigger a TLB refill exception, which enters the guest exception handlers without updating EPC. This appears as a guest triggered TLB refill on a host kernel mapped (host KSeg2) address, which is not handled correctly as user (guest) mode accesses to kernel (host) segments always generate address error exceptions. Signed-off-by: James Hogan <james.hogan@imgtec.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Radim Krčmář <rkrcmar@redhat.com> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: kvm@vger.kernel.org Cc: linux-mips@linux-mips.org Cc: <stable@vger.kernel.org> # 3.10.x- Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-05-29Merge branch 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linusLinus Torvalds19-189/+161
Pull more MIPS updates from Ralf Baechle: "This is the secondnd batch of MIPS patches for 4.7. Summary: CPS: - Copy EVA configuration when starting secondary VPs. EIC: - Clear Status IPL. Lasat: - Fix a few off by one bugs. lib: - Mark intrinsics notrace. Not only are the intrinsics uninteresting, it would cause infinite recursion. MAINTAINERS: - Add file patterns for MIPS BRCM device tree bindings. - Add file patterns for mips device tree bindings. MT7628: - Fix MT7628 pinmux typos. - wled_an pinmux gpio. - EPHY LEDs pinmux support. Pistachio: - Enable KASLR VDSO: - Build microMIPS VDSO for microMIPS kernels. - Fix aliasing warning by building with `-fno-strict-aliasing' for debugging but also tracing them might result in recursion. Misc: - Add missing FROZEN hotplug notifier transitions. - Fix clk binding example for varioius PIC32 devices. - Fix cpu interrupt controller node-names in the DT files. - Fix XPA CPU feature separation. - Fix write_gc0_* macros when writing zero. - Add inline asm encoding helpers. - Add missing VZ accessor microMIPS encodings. - Fix little endian microMIPS MSA encodings. - Add 64-bit HTW fields and fix its configuration. - Fix sigreturn via VDSO on microMIPS kernel. - Lots of typo fixes. - Add definitions of SegCtl registers and use them" * 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus: (49 commits) MIPS: Add missing FROZEN hotplug notifier transitions MIPS: Build microMIPS VDSO for microMIPS kernels MIPS: Fix sigreturn via VDSO on microMIPS kernel MIPS: devicetree: fix cpu interrupt controller node-names MIPS: VDSO: Build with `-fno-strict-aliasing' MIPS: Pistachio: Enable KASLR MIPS: lib: Mark intrinsics notrace MIPS: Fix 64-bit HTW configuration MIPS: Add 64-bit HTW fields MAINTAINERS: Add file patterns for mips device tree bindings MAINTAINERS: Add file patterns for mips brcm device tree bindings MIPS: Simplify DSP instruction encoding macros MIPS: Add missing tlbinvf/XPA microMIPS encodings MIPS: Fix little endian microMIPS MSA encodings MIPS: Add missing VZ accessor microMIPS encodings MIPS: Add inline asm encoding helpers MIPS: Spelling fix lets -> let's MIPS: VR41xx: Fix typo MIPS: oprofile: Fix typo MIPS: math-emu: Fix typo ...
2016-05-28MIPS: Add 64-bit HTW fieldsJames Hogan1-0/+8
Add field definitions for some of the 64-bit specific Hardware page Table Walker (HTW) register fields in PWSize and PWCtl, in preparation for fixing the 64-bit HTW configuration. Also print these fields out along with the others in print_htw_config(). 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/13363/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2016-05-28MIPS: Simplify DSP instruction encoding macrosJames Hogan1-90/+17
Simplify the DSP instruction wrapper macros which use explicit encodings for microMIPS and normal MIPS by using the new encoding macros and removing duplication. To me this makes it easier to read since it is much shorter, but it also ensures .insn is used, preventing objdump disassembling the microMIPS code as normal MIPS. Signed-off-by: James Hogan <james.hogan@imgtec.com> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/13314/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2016-05-28MIPS: Add missing tlbinvf/XPA microMIPS encodingsJames Hogan1-5/+7
Hardcoded MIPS instruction encodings are provided for tlbinvf, mfhc0 & mthc0 instructions, but microMIPS encodings are missing. I doubt any microMIPS cores exist at present which support these instructions, but the microMIPS encodings exist, and microMIPS cores may support them in the future. Add the missing microMIPS encodings using the new macros. Signed-off-by: James Hogan <james.hogan@imgtec.com> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/13313/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2016-05-28MIPS: Fix little endian microMIPS MSA encodingsJames Hogan2-62/+58
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>
2016-05-28MIPS: Add missing VZ accessor microMIPS encodingsJames Hogan1-9/+18
Toolchains may be used which support microMIPS but not VZ instructions (i.e. binutis 2.22 & 2.23), so extend the explicitly encoded versions of the guest COP0 register & guest TLB access macros to support microMIPS encodings too, using the new macros. This prevents non-microMIPS instructions being executed in microMIPS mode during CPU probe on cores supporting VZ (e.g. M5150), which cause reserved instruction exceptions early during boot. Fixes: bad50d79255a ("MIPS: Fix VZ probe gas errors with binutils <2.24") Signed-off-by: James Hogan <james.hogan@imgtec.com> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/13311/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2016-05-28MIPS: Add inline asm encoding helpersJames Hogan1-0/+27
To allow simplification of macros which use inline assembly to explicitly encode instructions, add a few simple abstractions to mipsregs.h which expand to specific microMIPS or normal MIPS encodings depending on what type of kernel is being built: _ASM_INSN_IF_MIPS(_enc) : Emit a 32bit MIPS instruction if microMIPS is not enabled. _ASM_INSN32_IF_MM(_enc) : Emit a 32bit microMIPS instruction if enabled. _ASM_INSN16_IF_MM(_enc) : Emit a 16bit microMIPS instruction if enabled. The macros can be used one after another since the MIPS / microMIPS macros are mutually exclusive, for example: __asm__ __volatile__( ".set push\n\t" ".set noat\n\t" "# mfgc0 $1, $%1, %2\n\t" _ASM_INSN_IF_MIPS(0x40610000 | %1 << 11 | %2) _ASM_INSN32_IF_MM(0x002004fc | %1 << 16 | %2 << 11) "move %0, $1\n\t" ".set pop" : "=r" (__res) : "i" (source), "i" (sel)); Signed-off-by: James Hogan <james.hogan@imgtec.com> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/13310/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2016-05-28MIPS: Spelling fix lets -> let'sRalf Baechle3-3/+3
As noticed by Sergei in the discussion of Andrea Gelmini's patch series. Signed-off-by: Ralf Baechle <ralf@linux-mips.org> Reported-by: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>
2016-05-28MIPS: IP22/IP28: Fix typoAndrea Gelmini1-1/+1
Signed-off-by: Andrea Gelmini <andrea.gelmini@gelma.net> Cc: adam.buchbinder@gmail.com Cc: trivial@kernel.org Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/13328/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2016-05-28MIPS: Cavium: Fix typoAndrea Gelmini4-4/+4
Signed-off-by: Andrea Gelmini <andrea.gelmini@gelma.net> Cc: david.daney@cavium.com Cc: janne.huttunen@nokia.com Cc: aaro.koskinen@nokia.com Cc: trivial@kernel.org Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/13324/ Patchwork: https://patchwork.linux-mips.org/patch/13325/ Patchwork: https://patchwork.linux-mips.org/patch/13326/ Patchwork: https://patchwork.linux-mips.org/patch/13327/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2016-05-28MIPS: MT: Fix typoAndrea Gelmini1-1/+1
Signed-off-by: Andrea Gelmini <andrea.gelmini@gelma.net> Cc: linux-mips@linux-mips.org Cc: trivial@kernel.org Patchwork: https://patchwork.linux-mips.org/patch/13323/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2016-05-28MIPS: Loongson64: Fix typoAndrea Gelmini1-1/+1
Signed-off-by: Andrea Gelmini <andrea.gelmini@gelma.net> Cc: chenhc@lemote.com Cc: viresh.kumar@linaro.org Cc: linux-mips@linux-mips.org Cc: trivial@kernel.org Patchwork: https://patchwork.linux-mips.org/patch/13322/ Patchwork: https://patchwork.linux-mips.org/patch/13332/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2016-05-28MIPS: IP32: Fix typoAndrea Gelmini1-1/+1
Signed-off-by: Andrea Gelmini <andrea.gelmini@gelma.net> Cc: trivial@kernel.org Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/13321/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>