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In TLB miss handlers, updating the perf counter is only useful
when performing a perf analysis. As it has a noticeable overhead,
let's only do it when needed.
In order to do so, the exit of the miss handlers will be patched
when starting/stopping 'perf': the first register restore
instruction of each exit point will be replaced by a jump to
the counting code.
Once this is done, CONFIG_PPC_8xx_PERF_EVENT becomes useless as
this feature doesn't add any overhead.
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
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This extends the instruction emulation infrastructure in sstep.c to
handle all the load and store instructions defined in the Power ISA
v3.0, except for the atomic memory operations, ldmx (which was never
implemented), lfdp/stfdp, and the vector element load/stores.
The instructions added are:
Integer loads and stores: lbarx, lharx, lqarx, stbcx., sthcx., stqcx.,
lq, stq.
VSX loads and stores: lxsiwzx, lxsiwax, stxsiwx, lxvx, lxvl, lxvll,
lxvdsx, lxvwsx, stxvx, stxvl, stxvll, lxsspx, lxsdx, stxsspx, stxsdx,
lxvw4x, lxsibzx, lxvh8x, lxsihzx, lxvb16x, stxvw4x, stxsibx, stxvh8x,
stxsihx, stxvb16x, lxsd, lxssp, lxv, stxsd, stxssp, stxv.
These instructions are handled both in the analyse_instr phase and in
the emulate_step phase.
The code for lxvd2ux and stxvd2ux has been taken out, as those
instructions were never implemented in any processor and have been
taken out of the architecture, and their opcodes have been reused for
other instructions in POWER9 (lxvb16x and stxvb16x).
The emulation for the VSX loads and stores uses helper functions
which don't access registers or memory directly, which can hopefully
be reused by KVM later.
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
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The instruction code for xxlor that commit 0016a4cf5582 ("powerpc:
Emulate most Book I instructions in emulate_step()", 2010-06-15)
added is actually the code for xxlnor. It is used in get_vsr()
and put_vsr() and the effect of the error is that if emulate_step
is used to emulate a VSX load or store from any register other
than vsr0, the bitwise complement of the correct value will be
loaded or stored. This corrects the error.
Fixes: 0016a4cf5582 ("powerpc: Emulate most Book I instructions in emulate_step()")
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
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Define interfaces (wrappers) to the 'copy' and 'paste'
instructions (which are new in PowerISA 3.0). These are intended to be
used to by NX driver(s) to submit Coprocessor Request Blocks (CRBs) to
the NX hardware engines.
Signed-off-by: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
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This adds powernv_get_random_darn() which utilises the darn instruction,
introduced in ISA v3.0/POWER9.
The darn instruction can potentially return an error, which is supported
by the get_random_seed() API, in normal usage if we see an error we just
return that to the caller.
However when detecting whether darn is functional at boot we try up to
10 times, before deciding that darn doesn't work and failing the
registration of get_random_seed(). That way an intermittent failure
at boot doesn't deprive the system of randomness until the next reboot.
Signed-off-by: Matt Brown <matthew.brown.dev@gmail.com>
[mpe: Move init into a function, tweak change log]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
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git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux
Pull powerpc updates from Michael Ellerman:
"Highlights include:
- Support for STRICT_KERNEL_RWX on 64-bit server CPUs.
- Platform support for FSP2 (476fpe) board
- Enable ZONE_DEVICE on 64-bit server CPUs.
- Generic & powerpc spin loop primitives to optimise busy waiting
- Convert VDSO update function to use new update_vsyscall() interface
- Optimisations to hypercall/syscall/context-switch paths
- Improvements to the CPU idle code on Power8 and Power9.
As well as many other fixes and improvements.
Thanks to: Akshay Adiga, Andrew Donnellan, Andrew Jeffery, Anshuman
Khandual, Anton Blanchard, Balbir Singh, Benjamin Herrenschmidt,
Christophe Leroy, Christophe Lombard, Colin Ian King, Dan Carpenter,
Gautham R. Shenoy, Hari Bathini, Ian Munsie, Ivan Mikhaylov, Javier
Martinez Canillas, Madhavan Srinivasan, Masahiro Yamada, Matt Brown,
Michael Neuling, Michal Suchanek, Murilo Opsfelder Araujo, Naveen N.
Rao, Nicholas Piggin, Oliver O'Halloran, Paul Mackerras, Pavel Machek,
Russell Currey, Santosh Sivaraj, Stephen Rothwell, Thiago Jung
Bauermann, Yang Li"
* tag 'powerpc-4.13-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: (158 commits)
powerpc/Kconfig: Enable STRICT_KERNEL_RWX for some configs
powerpc/mm/radix: Implement STRICT_RWX/mark_rodata_ro() for Radix
powerpc/mm/hash: Implement mark_rodata_ro() for hash
powerpc/vmlinux.lds: Align __init_begin to 16M
powerpc/lib/code-patching: Use alternate map for patch_instruction()
powerpc/xmon: Add patch_instruction() support for xmon
powerpc/kprobes/optprobes: Use patch_instruction()
powerpc/kprobes: Move kprobes over to patch_instruction()
powerpc/mm/radix: Fix execute permissions for interrupt_vectors
powerpc/pseries: Fix passing of pp0 in updatepp() and updateboltedpp()
powerpc/64s: Blacklist rtas entry/exit from kprobes
powerpc/64s: Blacklist functions invoked on a trap
powerpc/64s: Un-blacklist system_call() from kprobes
powerpc/64s: Move system_call() symbol to just after setting MSR_EE
powerpc/64s: Blacklist system_call() and system_call_common() from kprobes
powerpc/64s: Convert .L__replay_interrupt_return to a local label
powerpc64/elfv1: Only dereference function descriptor for non-text symbols
cxl: Export library to support IBM XSL
powerpc/dts: Use #include "..." to include local DT
powerpc/perf/hv-24x7: Aggregate result elements on POWER9 SMT8
...
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msgsnd doorbell exceptions are cleared when the doorbell interrupt is
taken. However if a doorbell exception causes a system reset interrupt
wake from power saving state, the message is not cleared. Processing
the doorbell from the system reset interrupt requires msgclr to avoid
taking the exception again.
Testing this plus the previous wakup direct patch gives:
original wakeup direct msgclr
Different threads, same core: 315k/s 264k/s 345k/s
Different cores: 235k/s 242k/s 242k/s
Net speedup is +10% for same core, and +3% for different core.
Reviewed-by: Gautham R. Shenoy <ego@linux.vnet.ibm.com>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
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On POWER9, we no longer have the restriction that we had on POWER8
where all threads in a core have to be in the same partition, so
the CPU threads are now independent. However, we still want to be
able to run guests with a virtual SMT topology, if only to allow
migration of guests from POWER8 systems to POWER9.
A guest that has a virtual SMT mode greater than 1 will expect to
be able to use the doorbell facility; it will expect the msgsndp
and msgclrp instructions to work appropriately and to be able to read
sensible values from the TIR (thread identification register) and
DPDES (directed privileged doorbell exception status) special-purpose
registers. However, since each CPU thread is a separate sub-processor
in POWER9, these instructions and registers can only be used within
a single CPU thread.
In order for these instructions to appear to act correctly according
to the guest's virtual SMT mode, we have to trap and emulate them.
We cause them to trap by clearing the HFSCR_MSGP bit in the HFSCR
register. The emulation is triggered by the hypervisor facility
unavailable interrupt that occurs when the guest uses them.
To cause a doorbell interrupt to occur within the guest, we set the
DPDES register to 1. If the guest has interrupts enabled, the CPU
will generate a doorbell interrupt and clear the DPDES register in
hardware. The DPDES hardware register for the guest is saved in the
vcpu->arch.vcore->dpdes field. Since this gets written by the guest
exit code, other VCPUs wishing to cause a doorbell interrupt don't
write that field directly, but instead set a vcpu->arch.doorbell_request
flag. This is consumed and set to 0 by the guest entry code, which
then sets DPDES to 1.
Emulating reads of the DPDES register is somewhat involved, because
it requires reading the doorbell pending interrupt status of all of the
VCPU threads in the virtual core, and if any of those VCPUs are
running, their doorbell status is only up-to-date in the hardware
DPDES registers of the CPUs where they are running. In order to get
a reasonable approximation of the current doorbell status, we send
those CPUs an IPI, causing an exit from the guest which will update
the vcpu->arch.vcore->dpdes field. We then use that value in
constructing the emulated DPDES register value.
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
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The ISA v3.0B copy-paste facility only requires cpabort when switching
to a process that has foreign real addresses mapped (direct access to
accelerators), to clear a potential copy buffer filled by a previous
thread. There is no accelerator driver implemented yet, so cpabort can
be removed. It can be be re-added when a driver is implemented.
POWER9 DD1 requires the copy buffer to always be cleared on context
switch, but if accelerators are not in use, then an unpaired copy from
a dummy region is sufficient to clear data out of the copy buffer.
This increases context switch performance by about 5% on POWER9.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
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Pull KVM updates from Paolo Bonzini:
"ARM:
- HYP mode stub supports kexec/kdump on 32-bit
- improved PMU support
- virtual interrupt controller performance improvements
- support for userspace virtual interrupt controller (slower, but
necessary for KVM on the weird Broadcom SoCs used by the Raspberry
Pi 3)
MIPS:
- basic support for hardware virtualization (ImgTec P5600/P6600/I6400
and Cavium Octeon III)
PPC:
- in-kernel acceleration for VFIO
s390:
- support for guests without storage keys
- adapter interruption suppression
x86:
- usual range of nVMX improvements, notably nested EPT support for
accessed and dirty bits
- emulation of CPL3 CPUID faulting
generic:
- first part of VCPU thread request API
- kvm_stat improvements"
* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (227 commits)
kvm: nVMX: Don't validate disabled secondary controls
KVM: put back #ifndef CONFIG_S390 around kvm_vcpu_kick
Revert "KVM: Support vCPU-based gfn->hva cache"
tools/kvm: fix top level makefile
KVM: x86: don't hold kvm->lock in KVM_SET_GSI_ROUTING
KVM: Documentation: remove VM mmap documentation
kvm: nVMX: Remove superfluous VMX instruction fault checks
KVM: x86: fix emulation of RSM and IRET instructions
KVM: mark requests that need synchronization
KVM: return if kvm_vcpu_wake_up() did wake up the VCPU
KVM: add explicit barrier to kvm_vcpu_kick
KVM: perform a wake_up in kvm_make_all_cpus_request
KVM: mark requests that do not need a wakeup
KVM: remove #ifndef CONFIG_S390 around kvm_vcpu_wake_up
KVM: x86: always use kvm_make_request instead of set_bit
KVM: add kvm_{test,clear}_request to replace {test,clear}_bit
s390: kvm: Cpu model support for msa6, msa7 and msa8
KVM: x86: remove irq disablement around KVM_SET_CLOCK/KVM_GET_CLOCK
kvm: better MWAIT emulation for guests
KVM: x86: virtualize cpuid faulting
...
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For completeness, this adds emulation of the lfiwax and lfiwzx
instructions. With this, all floating-point load and store instructions
as of Power ISA V2.07 are emulated.
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
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This adds emulation for the following integer loads and stores,
thus enabling them to be used in a guest for accessing emulated
MMIO locations.
- lhaux
- lwaux
- lwzux
- ldu
- lwa
- stdux
- stwux
- stdu
- ldbrx
- stdbrx
Previously, most of these would cause an emulation failure exit to
userspace, though ldu and lwa got treated incorrectly as ld, and
stdu got treated incorrectly as std.
This also tidies up some of the formatting and updates the comment
listing instructions that still need to be implemented.
With this, all integer loads and stores that are defined in the Power
ISA v2.07 are emulated, except for those that are permitted to trap
when used on cache-inhibited or write-through mappings (and which do
in fact trap on POWER8), that is, lmw/stmw, lswi/stswi, lswx/stswx,
lq/stq, and l[bhwdq]arx/st[bhwdq]cx.
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
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This adds missing stdx emulation for emulated MMIO accesses by KVM
guests. This allows the Mellanox mlx5_core driver from recent kernels
to work when MMIO emulation is enforced by userspace.
Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
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This patch provides the MMIO load/store emulation for instructions
of 'double & vector unsigned char & vector signed char & vector
unsigned short & vector signed short & vector unsigned int & vector
signed int & vector double '.
The instructions that this adds emulation for are:
- ldx, ldux, lwax,
- lfs, lfsx, lfsu, lfsux, lfd, lfdx, lfdu, lfdux,
- stfs, stfsx, stfsu, stfsux, stfd, stfdx, stfdu, stfdux, stfiwx,
- lxsdx, lxsspx, lxsiwax, lxsiwzx, lxvd2x, lxvw4x, lxvdsx,
- stxsdx, stxsspx, stxsiwx, stxvd2x, stxvw4x
[paulus@ozlabs.org - some cleanups, fixes and rework, make it
compile for Book E, fix build when PR KVM is built in]
Signed-off-by: Bin Lu <lblulb@linux.vnet.ibm.com>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
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POWER9 requires msgsync for receiver-side synchronization, and a DD1
workaround restricts IPIs to core-local.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
[mpe: Drop no longer needed asm feature macro changes]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
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Add new selftest that test emulate_step for Normal, Floating Point,
Vector and Vector Scalar - load/store instructions. Test should run
at boot time if CONFIG_KPROBES_SANITY_TEST and CONFIG_PPC64 is set.
Sample log:
emulate_step_test: ld : PASS
emulate_step_test: lwz : PASS
emulate_step_test: lwzx : PASS
emulate_step_test: std : PASS
emulate_step_test: ldarx / stdcx. : PASS
emulate_step_test: lfsx : PASS
emulate_step_test: stfsx : PASS
emulate_step_test: lfdx : PASS
emulate_step_test: stfdx : PASS
emulate_step_test: lvx : PASS
emulate_step_test: stvx : PASS
emulate_step_test: lxvd2x : PASS
emulate_step_test: stxvd2x : PASS
Signed-off-by: Ravi Bangoria <ravi.bangoria@linux.vnet.ibm.com>
[mpe: Drop start/complete lines, make it all __init]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
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Introduce __PPC_SH64() as a 64-bit variant to encode shift field in some
of the shift and rotate instructions operating on double-words. Convert
some of the BPF instruction macros to use the same.
Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
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IBM bit 31 (for the rest of us - bit 0) is a reserved field in the
instruction definition of mtspr and mfspr. Hardware is encouraged to
(and does) ignore it.
As a result, if userspace executes an mtspr DSCR with the reserved bit
set, we get a DSCR facility unavailable exception. The kernel fails to
match against the expected value/mask, and we silently return to
userspace to try and re-execute the same mtspr DSCR instruction. We
loop forever until the process is killed.
We should do something here, and it seems mirroring what hardware does
is the better option vs killing the process. While here, relax the
matching of mfspr PVR too.
Cc: stable@vger.kernel.org
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
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On POWER9 DD1, when we do a local TLB invalidate we also need to explicitly
invalidate the ERAT.
Signed-off-by: Michael Neuling <mikey@neuling.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
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git://git.kernel.org/pub/scm/linux/kernel/git/scottwood/linux into next
Freescale updates from Scott:
"Highlights include qbman support (a prerequisite for datapath drivers
such as ethernet), a PCI DMA fix+improvement, reset handler changes, more
8xx optimizations, and some cleanups and fixes."
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Tail calls allow JIT'ed eBPF programs to call into other JIT'ed eBPF
programs. This can be achieved either by:
(1) retaining the stack setup by the first eBPF program and having all
subsequent eBPF programs re-using it, or,
(2) by unwinding/tearing down the stack and having each eBPF program
deal with its own stack as it sees fit.
To ensure that this does not create loops, there is a limit to how many
tail calls can be done (currently 32). This requires the JIT'ed code to
maintain a count of the number of tail calls done so far.
Approach (1) is simple, but requires every eBPF program to have (almost)
the same prologue/epilogue, regardless of whether they need it. This is
inefficient for small eBPF programs which may not sometimes need a
prologue at all. As such, to minimize impact of tail call
implementation, we use approach (2) here which needs each eBPF program
in the chain to use its own prologue/epilogue. This is not ideal when
many tail calls are involved and when all the eBPF programs in the chain
have similar prologue/epilogue. However, the impact is restricted to
programs that do tail calls. Individual eBPF programs are not affected.
We maintain the tail call count in a fixed location on the stack and
updated tail call count values are passed in through this. The very
first eBPF program in a chain sets this up to 0 (the first 2
instructions). Subsequent tail calls skip the first two eBPF JIT
instructions to maintain the count. For programs that don't do tail
calls themselves, the first two instructions are NOPs.
Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
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Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Scott Wood <oss@buserror.net>
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git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux
Pull powerpc updates from Michael Ellerman:
"Highlights:
- PowerNV PCI hotplug support.
- Lots more Power9 support.
- eBPF JIT support on ppc64le.
- Lots of cxl updates.
- Boot code consolidation.
Bug fixes:
- Fix spin_unlock_wait() from Boqun Feng
- Fix stack pointer corruption in __tm_recheckpoint() from Michael
Neuling
- Fix multiple bugs in memory_hotplug_max() from Bharata B Rao
- mm: Ensure "special" zones are empty from Oliver O'Halloran
- ftrace: Separate the heuristics for checking call sites from
Michael Ellerman
- modules: Never restore r2 for a mprofile-kernel style mcount() call
from Michael Ellerman
- Fix endianness when reading TCEs from Alexey Kardashevskiy
- start rtasd before PCI probing from Greg Kurz
- PCI: rpaphp: Fix slot registration for multiple slots under a PHB
from Tyrel Datwyler
- powerpc/mm: Add memory barrier in __hugepte_alloc() from Sukadev
Bhattiprolu
Cleanups & fixes:
- Drop support for MPIC in pseries from Rashmica Gupta
- Define and use PPC64_ELF_ABI_v2/v1 from Michael Ellerman
- Remove unused symbols in asm-offsets.c from Rashmica Gupta
- Fix SRIOV not building without EEH enabled from Russell Currey
- Remove kretprobe_trampoline_holder from Thiago Jung Bauermann
- Reduce log level of PCI I/O space warning from Benjamin
Herrenschmidt
- Add array bounds checking to crash_shutdown_handlers from Suraj
Jitindar Singh
- Avoid -maltivec when using clang integrated assembler from Anton
Blanchard
- Fix array overrun in ppc_rtas() syscall from Andrew Donnellan
- Fix error return value in cmm_mem_going_offline() from Rasmus
Villemoes
- export cpu_to_core_id() from Mauricio Faria de Oliveira
- Remove old symbols from defconfigs from Andrew Donnellan
- Update obsolete comments in setup_32.c about entry conditions from
Benjamin Herrenschmidt
- Add comment explaining the purpose of setup_kdump_trampoline() from
Benjamin Herrenschmidt
- Merge the RELOCATABLE config entries for ppc32 and ppc64 from Kevin
Hao
- Remove RELOCATABLE_PPC32 from Kevin Hao
- Fix .long's in tlb-radix.c to more meaningful from Balbir Singh
Minor cleanups & fixes:
- Andrew Donnellan, Anna-Maria Gleixner, Anton Blanchard, Benjamin
Herrenschmidt, Bharata B Rao, Christophe Leroy, Colin Ian King,
Geliang Tang, Greg Kurz, Madhavan Srinivasan, Michael Ellerman,
Michael Ellerman, Stephen Rothwell, Stewart Smith.
Freescale updates from Scott:
- "Highlights include more 8xx optimizations, device tree updates,
and MVME7100 support."
PowerNV PCI hotplug from Gavin Shan:
- PCI: Add pcibios_setup_bridge()
- Override pcibios_setup_bridge()
- Remove PCI_RESET_DELAY_US
- Move pnv_pci_ioda_setup_opal_tce_kill() around
- Increase PE# capacity
- Allocate PE# in reverse order
- Create PEs in pcibios_setup_bridge()
- Setup PE for root bus
- Extend PCI bridge resources
- Make pnv_ioda_deconfigure_pe() visible
- Dynamically release PE
- Update bridge windows on PCI plug
- Delay populating pdn
- Support PCI slot ID
- Use PCI slot reset infrastructure
- Introduce pnv_pci_get_slot_id()
- Functions to get/set PCI slot state
- PCI/hotplug: PowerPC PowerNV PCI hotplug driver
- Print correct PHB type names
Power9 idle support from Shreyas B. Prabhu:
- set power_save func after the idle states are initialized
- Use PNV_THREAD_WINKLE macro while requesting for winkle
- make hypervisor state restore a function
- Rename idle_power7.S to idle_book3s.S
- Rename reusable idle functions to hardware agnostic names
- Make pnv_powersave_common more generic
- abstraction for saving SPRs before entering deep idle states
- Add platform support for stop instruction
- cpuidle/powernv: Use CPUIDLE_STATE_MAX instead of MAX_POWERNV_IDLE_STATES
- cpuidle/powernv: cleanup cpuidle-powernv.c
- cpuidle/powernv: Add support for POWER ISA v3 idle states
- Use deepest stop state when cpu is offlined
Power9 PMU from Madhavan Srinivasan:
- factor out power8 pmu macros and defines
- factor out power8 pmu functions
- factor out power8 __init_pmu code
- Add power9 event list macros for generic and cache events
- Power9 PMU support
- Export Power9 generic and cache events to sysfs
Power9 preliminary interrupt & PCI support from Benjamin Herrenschmidt:
- Add XICS emulation APIs
- Move a few exception common handlers to make room
- Add support for HV virtualization interrupts
- Add mechanism to force a replay of interrupts
- Add ICP OPAL backend
- Discover IODA3 PHBs
- pci: Remove obsolete SW invalidate
- opal: Add real mode call wrappers
- Rename TCE invalidation calls
- Remove SWINV constants and obsolete TCE code
- Rework accessing the TCE invalidate register
- Fallback to OPAL for TCE invalidations
- Use the device-tree to get available range of M64's
- Check status of a PHB before using it
- pci: Don't try to allocate resources that will be reassigned
Other Power9:
- Send SIGBUS on unaligned copy and paste from Chris Smart
- Large Decrementer support from Oliver O'Halloran
- Load Monitor Register Support from Jack Miller
Performance improvements from Anton Blanchard:
- Avoid load hit store in __giveup_fpu() and __giveup_altivec()
- Avoid load hit store in setup_sigcontext()
- Remove assembly versions of strcpy, strcat, strlen and strcmp
- Align hot loops of some string functions
eBPF JIT from Naveen N. Rao:
- Fix/enhance 32-bit Load Immediate implementation
- Optimize 64-bit Immediate loads
- Introduce rotate immediate instructions
- A few cleanups
- Isolate classic BPF JIT specifics into a separate header
- Implement JIT compiler for extended BPF
Operator Panel driver from Suraj Jitindar Singh:
- devicetree/bindings: Add binding for operator panel on FSP machines
- Add inline function to get rc from an ASYNC_COMP opal_msg
- Add driver for operator panel on FSP machines
Sparse fixes from Daniel Axtens:
- make some things static
- Introduce asm-prototypes.h
- Include headers containing prototypes
- Use #ifdef __BIG_ENDIAN__ #else for REG_BYTE
- kvm: Clarify __user annotations
- Pass endianness to sparse
- Make ppc_md.{halt, restart} __noreturn
MM fixes & cleanups from Aneesh Kumar K.V:
- radix: Update LPCR HR bit as per ISA
- use _raw variant of page table accessors
- Compile out radix related functions if RADIX_MMU is disabled
- Clear top 16 bits of va only on older cpus
- Print formation regarding the the MMU mode
- hash: Update SDR1 size encoding as documented in ISA 3.0
- radix: Update PID switch sequence
- radix: Update machine call back to support new HCALL.
- radix: Add LPID based tlb flush helpers
- radix: Add a kernel command line to disable radix
- Cleanup LPCR defines
Boot code consolidation from Benjamin Herrenschmidt:
- Move epapr_paravirt_early_init() to early_init_devtree()
- cell: Don't use flat device-tree after boot
- ge_imp3a: Don't use the flat device-tree after boot
- mpc85xx_ds: Don't use the flat device-tree after boot
- mpc85xx_rdb: Don't use the flat device-tree after boot
- Don't test for machine type in rtas_initialize()
- Don't test for machine type in smp_setup_cpu_maps()
- dt: Add of_device_compatible_match()
- Factor do_feature_fixup calls
- Move 64-bit feature fixup earlier
- Move 64-bit memory reserves to setup_arch()
- Use a cachable DART
- Move FW feature probing out of pseries probe()
- Put exception configuration in a common place
- Remove early allocation of the SMU command buffer
- Move MMU backend selection out of platform code
- pasemi: Remove IOBMAP allocation from platform probe()
- mm/hash: Don't use machine_is() early during boot
- Don't test for machine type to detect HEA special case
- pmac: Remove spurrious machine type test
- Move hash table ops to a separate structure
- Ensure that ppc_md is empty before probing for machine type
- Move 64-bit probe_machine() to later in the boot process
- Move 32-bit probe() machine to later in the boot process
- Get rid of ppc_md.init_early()
- Move the boot time info banner to a separate function
- Move setting of {i,d}cache_bsize to initialize_cache_info()
- Move the content of setup_system() to setup_arch()
- Move cache info inits to a separate function
- Re-order the call to smp_setup_cpu_maps()
- Re-order setup_panic()
- Make a few boot functions __init
- Merge 32-bit and 64-bit setup_arch()
Other new features:
- tty/hvc: Use IRQF_SHARED for OPAL hvc consoles from Sam Mendoza-Jonas
- tty/hvc: Use opal irqchip interface if available from Sam Mendoza-Jonas
- powerpc: Add module autoloading based on CPU features from Alastair D'Silva
- crypto: vmx - Convert to CPU feature based module autoloading from Alastair D'Silva
- Wake up kopald polling thread before waiting for events from Benjamin Herrenschmidt
- xmon: Dump ISA 2.06 SPRs from Michael Ellerman
- xmon: Dump ISA 2.07 SPRs from Michael Ellerman
- Add a parameter to disable 1TB segs from Oliver O'Halloran
- powerpc/boot: Add OPAL console to epapr wrappers from Oliver O'Halloran
- Assign fixed PHB number based on device-tree properties from Guilherme G. Piccoli
- pseries: Add pseries hotplug workqueue from John Allen
- pseries: Add support for hotplug interrupt source from John Allen
- pseries: Use kernel hotplug queue for PowerVM hotplug events from John Allen
- pseries: Move property cloning into its own routine from Nathan Fontenot
- pseries: Dynamic add entires to associativity lookup array from Nathan Fontenot
- pseries: Auto-online hotplugged memory from Nathan Fontenot
- pseries: Remove call to memblock_add() from Nathan Fontenot
cxl:
- Add set and get private data to context struct from Michael Neuling
- make base more explicitly non-modular from Paul Gortmaker
- Use for_each_compatible_node() macro from Wei Yongjun
- Frederic Barrat
- Abstract the differences between the PSL and XSL
- Make vPHB device node match adapter's
- Philippe Bergheaud
- Add mechanism for delivering AFU driver specific events
- Ignore CAPI adapters misplaced in switched slots
- Refine slice error debug messages
- Andrew Donnellan
- static-ify variables to fix sparse warnings
- PCI/hotplug: pnv_php: export symbols and move struct types needed by cxl
- PCI/hotplug: pnv_php: handle OPAL_PCI_SLOT_OFFLINE power state
- Add cxl_check_and_switch_mode() API to switch bi-modal cards
- remove dead Kconfig options
- fix potential NULL dereference in free_adapter()
- Ian Munsie
- Update process element after allocating interrupts
- Add support for CAPP DMA mode
- Fix allowing bogus AFU descriptors with 0 maximum processes
- Fix allocating a minimum of 2 pages for the SPA
- Fix bug where AFU disable operation had no effect
- Workaround XSL bug that does not clear the RA bit after a reset
- Fix NULL pointer dereference on kernel contexts with no AFU interrupts
- powerpc/powernv: Split cxl code out into a separate file
- Add cxl_slot_is_supported API
- Enable bus mastering for devices using CAPP DMA mode
- Move cxl_afu_get / cxl_afu_put to base
- Allow a default context to be associated with an external pci_dev
- Do not create vPHB if there are no AFU configuration records
- powerpc/powernv: Add support for the cxl kernel api on the real phb
- Add support for using the kernel API with a real PHB
- Add kernel APIs to get & set the max irqs per context
- Add preliminary workaround for CX4 interrupt limitation
- Add support for interrupts on the Mellanox CX4
- Workaround PE=0 hardware limitation in Mellanox CX4
- powerpc/powernv: Fix pci-cxl.c build when CONFIG_MODULES=n
selftests:
- Test unaligned copy and paste from Chris Smart
- Load Monitor Register Tests from Jack Miller
- Cyril Bur
- exec() with suspended transaction
- Use signed long to read perf_event_paranoid
- Fix usage message in context_switch
- Fix generation of vector instructions/types in context_switch
- Michael Ellerman
- Use "Delta" rather than "Error" in normal output
- Import Anton's mmap & futex micro benchmarks
- Add a test for PROT_SAO"
* tag 'powerpc-4.8-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: (263 commits)
powerpc/mm: Parenthesise IS_ENABLED() in if condition
tty/hvc: Use opal irqchip interface if available
tty/hvc: Use IRQF_SHARED for OPAL hvc consoles
selftests/powerpc: exec() with suspended transaction
powerpc: Improve comment explaining why we modify VRSAVE
powerpc/mm: Drop unused externs for hpte_init_beat[_v3]()
powerpc/mm: Rename hpte_init_lpar() and move the fallback to a header
powerpc/mm: Fix build break when PPC_NATIVE=n
crypto: vmx - Convert to CPU feature based module autoloading
powerpc: Add module autoloading based on CPU features
powerpc/powernv/ioda: Fix endianness when reading TCEs
powerpc/mm: Add memory barrier in __hugepte_alloc()
powerpc/modules: Never restore r2 for a mprofile-kernel style mcount() call
powerpc/ftrace: Separate the heuristics for checking call sites
powerpc: Merge 32-bit and 64-bit setup_arch()
powerpc/64: Make a few boot functions __init
powerpc: Re-order setup_panic()
powerpc: Re-order the call to smp_setup_cpu_maps()
powerpc/32: Move cache info inits to a separate function
powerpc/64: Move the content of setup_system() to setup_arch()
...
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Update the PID switch as per ISA doc. slbia is needed in radix to
invalidate any implementation specific lookaside information.
We use the .long format due to build errors with the below compiler
version.
gcc (Ubuntu 5.3.1-14ubuntu2.1) 5.3.1 20160413
GNU assembler (GNU Binutils for Ubuntu) 2.26
CC arch/powerpc/mm//mmu_context_book3s64.o
{standard input}: Assembler messages:
{standard input}:506: Error: junk at end of line: `0x7'
scripts/Makefile.build:291: recipe for target 'arch/powerpc/mm//mmu_context_book3s64.o' failed
make[1]: *** [arch/powerpc/mm//mmu_context_book3s64.o] Error 1
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
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The .longs with the shifts are harder to read, use more meaningful names
for the opcodes. PPC_TLBIE_5 is introduced for the 5 opcode variation of
the instruction due to an existing op-code for the 2 opcode variant.
Signed-off-by: Balbir Singh <bsingharora@gmail.com>
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
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POWER ISA v3 defines a new idle processor core mechanism. In summary,
a) new instruction named stop is added. This instruction replaces
instructions like nap, sleep, rvwinkle.
b) new per thread SPR named Processor Stop Status and Control Register
(PSSCR) is added which controls the behavior of stop instruction.
PSSCR layout:
----------------------------------------------------------
| PLS | /// | SD | ESL | EC | PSLL | /// | TR | MTL | RL |
----------------------------------------------------------
0 4 41 42 43 44 48 54 56 60
PSSCR key fields:
Bits 0:3 - Power-Saving Level Status. This field indicates the lowest
power-saving state the thread entered since stop instruction was last
executed.
Bit 42 - Enable State Loss
0 - No state is lost irrespective of other fields
1 - Allows state loss
Bits 44:47 - Power-Saving Level Limit
This limits the power-saving level that can be entered into.
Bits 60:63 - Requested Level
Used to specify which power-saving level must be entered on executing
stop instruction
This patch adds support for stop instruction and PSSCR handling.
Reviewed-by: Gautham R. Shenoy <ego@linux.vnet.ibm.com>
Signed-off-by: Shreyas B. Prabhu <shreyas@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
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Use the vector polynomial multiply-sum instructions in POWER8 to
speed up crc32c.
This is just over 41x faster than the slice-by-8 method that it
replaces. Measurements on a 4.1 GHz POWER8 show it sustaining
52 GiB/sec.
A simple btrfs write performance test:
dd if=/dev/zero of=/mnt/tmpfile bs=1M count=4096
sync
is over 3.7x faster.
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
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Calling ISA 3.0 instructions copy, copy_first, paste and paste_last
generates an alignment fault when copying or pasting unaligned
data (128 byte). We catch this and send SIGBUS to the userspace
process that caused it.
We do not emulate these because paste may contain additional metadata
when pasting to a co-processor and paste_last is the synchronisation
point for preceding copy/paste sequences.
Thanks to Michael Neuling <mikey@neuling.org> for his help.
Signed-off-by: Chris Smart <chris@distroguy.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
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PPC64 eBPF JIT compiler.
Enable with:
echo 1 > /proc/sys/net/core/bpf_jit_enable
or
echo 2 > /proc/sys/net/core/bpf_jit_enable
... to see the generated JIT code. This can further be processed with
tools/net/bpf_jit_disasm.
With CONFIG_TEST_BPF=m and 'modprobe test_bpf':
test_bpf: Summary: 305 PASSED, 0 FAILED, [297/297 JIT'ed]
... on both ppc64 BE and LE.
The details of the approach are documented through various comments in
the code.
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
|
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Since we will be using the rotate immediate instructions for extended
BPF JIT, let's introduce macros for the same. And since the shift
immediate operations use the rotate immediate instructions, let's redo
those macros to use the newly introduced instructions.
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
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The copy paste facility introduced in POWER9 provides an optimised
mechanism for a userspace application to copy a cacheline. This is
provided by a pair of instructions, copy and paste, while a third,
cp_abort (copy paste abort), provides a clean up of the state in case of
a failure.
The copy instruction will read a 128 byte cacheline and store it in an
internal buffer. The subsequent paste instruction will store this
internal buffer to memory and set a CR field if the paste succeeds.
Since the state of the copy paste buffer is internal (and not
architecturally visible), in the unlikely event of a context switch, the
state cannot be stored and the paste should therefore fail.
The cp_abort instruction exists to fail and clean up any such
interrupted copy paste sequence and is to be called by the kernel as
part of the context switch. Doing so prevents data from a preceding copy
in one process leaking into the paste of another.
This code enables use of the cp_abort instruction if a supported
processor is detected.
NOTE: this is for userspace only, not in kernel, and does not deal
with KVM guests.
Patch created with much assistance from Michael Neuling
<mikey@neuling.org>
Signed-off-by: Chris Smart <chris@distroguy.com>
Reviewed-by: Cyril Bur <cyrilbur@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
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POWER8"
This reverts commit 9678cdaae939 ("Use the POWER8 Micro Partition
Prefetch Engine in KVM HV on POWER8") because the original commit had
multiple, partly self-cancelling bugs, that could cause occasional
memory corruption.
In fact the logmpp instruction was incorrectly using register r0 as the
source of the buffer address and operation code, and depending on what
was in r0, it would either do nothing or corrupt the 64k page pointed to
by r0.
The logmpp instruction encoding and the operation code definitions could
be corrected, but then there is the problem that there is no clearly
defined way to know when the hardware has finished writing to the
buffer.
The original commit attempted to work around this by aborting the
write-out before starting the prefetch, but this is ineffective in the
case where the virtual core is now executing on a different physical
core from the one where the write-out was initiated.
These problems plus advice from the hardware designers not to use the
function (since the measured performance improvement from using the
feature was actually mostly negative), mean that reverting the code is
the best option.
Fixes: 9678cdaae939 ("Use the POWER8 Micro Partition Prefetch Engine in KVM HV on POWER8")
Signed-off-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
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When compiling the KVM code for POWER with "make C=1", sparse
complains about functions missing proper prototypes and a 64-bit
constant missing the ULL prefix. Let's fix this by making the
functions static or by including the proper header with the
prototypes, and by appending a ULL prefix to the constant
PPC_MPPE_ADDRESS_MASK.
Signed-off-by: Thomas Huth <thuth@redhat.com>
Signed-off-by: Alexander Graf <agraf@suse.de>
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Add the asm ICSWX and ICSWEPX opcodes. Add definitions for the
Coprocessor Request structures needed to use the icswx calls to
coprocessors. Add icswx() function to perform the ICSWX asm
using the provided Coprocessor Command Word value and
Coprocessor Request Block structure.
This is required for communication with the NX-842 coprocessor on
a PowerNV system.
Signed-off-by: Dan Streetman <ddstreet@ieee.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
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|
Conflicts:
drivers/net/usb/asix_common.c
drivers/net/usb/sr9800.c
drivers/net/usb/usbnet.c
include/linux/usb/usbnet.h
net/ipv4/tcp_ipv4.c
net/ipv6/tcp_ipv6.c
The TCP conflicts were overlapping changes. In 'net' we added a
READ_ONCE() to the socket cached RX route read, whilst in 'net-next'
Eric Dumazet touched the surrounding code dealing with how mini
sockets are handled.
With USB, it's a case of the same bug fix first going into net-next
and then I cherry picked it back into net.
Signed-off-by: David S. Miller <davem@davemloft.net>
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Since we can now use hypervisor doorbells for host IPIs, this makes
sure we clear the host IPI flag when taking a doorbell interrupt, and
clears any pending doorbell IPI in pnv_smp_cpu_kill_self() (as we
already do for IPIs sent via the XICS interrupt controller). Otherwise
if there did happen to be a leftover pending doorbell interrupt for
an offline CPU thread for any reason, it would prevent that thread from
going into a power-saving mode; it would instead keep waking up because
of the interrupt.
Signed-off-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
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|
Signed-off-by: Denis Kirjanov <kda@linux-powerpc.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
|
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git://git.kernel.org/pub/scm/linux/kernel/git/mpe/linux
Pull second batch of powerpc updates from Michael Ellerman:
"The highlight is the series that reworks the idle management on
powernv, which allows us to use deeper idle states on those machines.
There's the fix from Anton for the "BUG at kernel/smpboot.c:134!"
problem.
An i2c driver for powernv. This is acked by Wolfram Sang, and he
asked that we take it through the powerpc tree.
A fix for audit from rgb at Red Hat, acked by Paul Moore who is one of
the audit maintainers.
A patch from Ben to export the symbol map of our OPAL firmware as a
sysfs file, so that tools can use it.
Also some CXL fixes, a couple of powerpc perf fixes, a fix for
smt-enabled, and the patch to add __force to get_user() so we can use
bitwise types"
* tag 'powerpc-3.19-2' of git://git.kernel.org/pub/scm/linux/kernel/git/mpe/linux:
powerpc/powernv: Ignore smt-enabled on Power8 and later
powerpc/uaccess: Allow get_user() with bitwise types
powerpc/powernv: Expose OPAL firmware symbol map
powernv/powerpc: Add winkle support for offline cpus
powernv/cpuidle: Redesign idle states management
powerpc/powernv: Enable Offline CPUs to enter deep idle states
powerpc/powernv: Switch off MMU before entering nap/sleep/rvwinkle mode
i2c: Driver to expose PowerNV platform i2c busses
powerpc: add little endian flag to syscall_get_arch()
power/perf/hv-24x7: Use kmem_cache_free() instead of kfree
powerpc/perf/hv-24x7: Use per-cpu page buffer
cxl: Unmap MMIO regions when detaching a context
cxl: Add timeout to process element commands
cxl: Change contexts_lock to a mutex to fix sleep while atomic bug
powerpc: Secondary CPUs must set cpu_callin_map after setting active and online
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Winkle is a deep idle state supported in power8 chips. A core enters
winkle when all the threads of the core enter winkle. In this state
power supply to the entire chiplet i.e core, private L2 and private L3
is turned off. As a result it gives higher powersavings compared to
sleep.
But entering winkle results in a total hypervisor state loss. Hence the
hypervisor context has to be preserved before entering winkle and
restored upon wake up.
Power-on Reset Engine (PORE) is a dedicated engine which is responsible
for powering on the chiplet during wake up. It can be programmed to
restore the register contests of a few specific registers. This patch
uses PORE to restore register state wherever possible and uses stack to
save and restore rest of the necessary registers.
With hypervisor state restore things fall under three categories-
per-core state, per-subcore state and per-thread state. To manage this,
extend the infrastructure introduced for sleep. Mainly we add a paca
variable subcore_sibling_mask. Using this and the core_idle_state we can
distingush first thread in core and subcore.
Signed-off-by: Shreyas B. Prabhu <shreyas@linux.vnet.ibm.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: linuxppc-dev@lists.ozlabs.org
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
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Add BPF extension SKF_AD_PKTTYPE to ppc JIT to load
skb->pkt_type field.
Before:
[ 88.262622] test_bpf: #11 LD_IND_NET 86 97 99 PASS
[ 88.265740] test_bpf: #12 LD_PKTTYPE 109 107 PASS
After:
[ 80.605964] test_bpf: #11 LD_IND_NET 44 40 39 PASS
[ 80.607370] test_bpf: #12 LD_PKTTYPE 9 9 PASS
CC: Alexei Starovoitov<alexei.starovoitov@gmail.com>
CC: Michael Ellerman<mpe@ellerman.id.au>
Cc: Matt Evans <matt@ozlabs.org>
Signed-off-by: Denis Kirjanov <kda@linux-powerpc.org>
v2: Added test rusults
Signed-off-by: David S. Miller <davem@davemloft.net>
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Pull second round of KVM changes from Paolo Bonzini:
"Here are the PPC and ARM changes for KVM, which I separated because
they had small conflicts (respectively within KVM documentation, and
with 3.16-rc changes). Since they were all within the subsystem, I
took care of them.
Stephen Rothwell reported some snags in PPC builds, but they are all
fixed now; the latest linux-next report was clean.
New features for ARM include:
- KVM VGIC v2 emulation on GICv3 hardware
- Big-Endian support for arm/arm64 (guest and host)
- Debug Architecture support for arm64 (arm32 is on Christoffer's todo list)
And for PPC:
- Book3S: Good number of LE host fixes, enable HV on LE
- Book3S HV: Add in-guest debug support
This release drops support for KVM on the PPC440. As a result, the
PPC merge removes more lines than it adds. :)
I also included an x86 change, since Davidlohr tied it to an
independent bug report and the reporter quickly provided a Tested-by;
there was no reason to wait for -rc2"
* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (122 commits)
KVM: Move more code under CONFIG_HAVE_KVM_IRQFD
KVM: nVMX: fix "acknowledge interrupt on exit" when APICv is in use
KVM: nVMX: Fix nested vmexit ack intr before load vmcs01
KVM: PPC: Enable IRQFD support for the XICS interrupt controller
KVM: Give IRQFD its own separate enabling Kconfig option
KVM: Move irq notifier implementation into eventfd.c
KVM: Move all accesses to kvm::irq_routing into irqchip.c
KVM: irqchip: Provide and use accessors for irq routing table
KVM: Don't keep reference to irq routing table in irqfd struct
KVM: PPC: drop duplicate tracepoint
arm64: KVM: fix 64bit CP15 VM access for 32bit guests
KVM: arm64: GICv3: mandate page-aligned GICV region
arm64: KVM: GICv3: move system register access to msr_s/mrs_s
KVM: PPC: PR: Handle FSCR feature deselects
KVM: PPC: HV: Remove generic instruction emulation
KVM: PPC: BOOKEHV: rename e500hv_spr to bookehv_spr
KVM: PPC: Remove DCR handling
KVM: PPC: Expose helper functions for data/inst faults
KVM: PPC: Separate loadstore emulation from priv emulation
KVM: PPC: Handle magic page in kvmppc_ld/st
...
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The general idea is that each core will release all of its
threads into the secondary thread startup code, which will
eventually wait in the secondary core holding area, for the
appropriate bit in the PACA to be set. The kick_cpu function
pointer will set that bit in the PACA, and thus "release"
the core/thread to boot. We also need to do a few things that
U-Boot normally does for CPUs (like enable branch prediction).
Signed-off-by: Andy Fleming <afleming@freescale.com>
[scottwood@freescale.com: various changes, including only enabling
threads if Linux wants to kick them]
Signed-off-by: Scott Wood <scottwood@freescale.com>
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The POWER8 processor has a Micro Partition Prefetch Engine, which is
a fancy way of saying "has way to store and load contents of L2 or
L2+MRU way of L3 cache". We initiate the storing of the log (list of
addresses) using the logmpp instruction and start restore by writing
to a SPR.
The logmpp instruction takes parameters in a single 64bit register:
- starting address of the table to store log of L2/L2+L3 cache contents
- 32kb for L2
- 128kb for L2+L3
- Aligned relative to maximum size of the table (32kb or 128kb)
- Log control (no-op, L2 only, L2 and L3, abort logout)
We should abort any ongoing logging before initiating one.
To initiate restore, we write to the MPPR SPR. The format of what to write
to the SPR is similar to the logmpp instruction parameter:
- starting address of the table to read from (same alignment requirements)
- table size (no data, until end of table)
- prefetch rate (from fastest possible to slower. about every 8, 16, 24 or
32 cycles)
The idea behind loading and storing the contents of L2/L3 cache is to
reduce memory latency in a system that is frequently swapping vcores on
a physical CPU.
The best case scenario for doing this is when some vcores are doing very
cache heavy workloads. The worst case is when they have about 0 cache hits,
so we just generate needless memory operations.
This implementation just does L2 store/load. In my benchmarks this proves
to be useful.
Benchmark 1:
- 16 core POWER8
- 3x Ubuntu 14.04LTS guests (LE) with 8 VCPUs each
- No split core/SMT
- two guests running sysbench memory test.
sysbench --test=memory --num-threads=8 run
- one guest running apache bench (of default HTML page)
ab -n 490000 -c 400 http://localhost/
This benchmark aims to measure performance of real world application (apache)
where other guests are cache hot with their own workloads. The sysbench memory
benchmark does pointer sized writes to a (small) memory buffer in a loop.
In this benchmark with this patch I can see an improvement both in requests
per second (~5%) and in mean and median response times (again, about 5%).
The spread of minimum and maximum response times were largely unchanged.
benchmark 2:
- Same VM config as benchmark 1
- all three guests running sysbench memory benchmark
This benchmark aims to see if there is a positive or negative affect to this
cache heavy benchmark. Although due to the nature of the benchmark (stores) we
may not see a difference in performance, but rather hopefully an improvement
in consistency of performance (when vcore switched in, don't have to wait
many times for cachelines to be pulled in)
The results of this benchmark are improvements in consistency of performance
rather than performance itself. With this patch, the few outliers in duration
go away and we get more consistent performance in each guest.
benchmark 3:
- same 3 guests and CPU configuration as benchmark 1 and 2.
- two idle guests
- 1 guest running STREAM benchmark
This scenario also saw performance improvement with this patch. On Copy and
Scale workloads from STREAM, I got 5-6% improvement with this patch. For
Add and triad, it was around 10% (or more).
benchmark 4:
- same 3 guests as previous benchmarks
- two guests running sysbench --memory, distinctly different cache heavy
workload
- one guest running STREAM benchmark.
Similar improvements to benchmark 3.
benchmark 5:
- 1 guest, 8 VCPUs, Ubuntu 14.04
- Host configured with split core (SMT8, subcores-per-core=4)
- STREAM benchmark
In this benchmark, we see a 10-20% performance improvement across the board
of STREAM benchmark results with this patch.
Based on preliminary investigation and microbenchmarks
by Prerna Saxena <prerna@linux.vnet.ibm.com>
Signed-off-by: Stewart Smith <stewart@linux.vnet.ibm.com>
Acked-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Alexander Graf <agraf@suse.de>
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Currently DIVWU stands for *signed* divw opcode:
7d 2a 4b 96 divwu r9,r10,r9
7d 2a 4b d6 divw r9,r10,r9
Use the *unsigned* divw opcode for DIVWU.
Suggested-by: Vassili Karpov <av1474@comtv.ru>
Reviewed-by: Vassili Karpov <av1474@comtv.ru>
Signed-off-by: Vladimir Murzin <murzin.v@gmail.com>
Acked-by: Matt Evans <matt@ozlabs.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
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This enables the Berkeley Packet Filter JIT compiler
for the PowerPC running in 64bit Little Endian.
Signed-off-by: Philippe Bergheaud <felix@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
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Reserved fields of the sync instruction have been used for other
instructions (e.g. lwsync). On processors that do not support variants
of the sync instruction, emulate it by executing a sync to subsume the
effect of the intended instruction.
Signed-off-by: James Yang <James.Yang@freescale.com>
[scottwood@freescale.com: whitespace and subject line fix]
Signed-off-by: Scott Wood <scottwood@freescale.com>
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save/restore
The elements within VSX loads and stores are big endian ordered
regardless of endianness. Our VSX context save/restore code uses
lxvd2x and stxvd2x which is a 2x doubleword operation. This means
the two doublewords will be swapped and we have to perform another
swap to undo it.
We need to do this on save and restore.
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
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Opcode and xopcode are useful definitions not just for KVM. Move these
definitions to asm/ppc-opcode.h for public use.
Also add the opcodes for LHAUX and LWZUX.
Signed-off-by: Jia Hongtao <hongtao.jia@freescale.com>
Signed-off-by: Li Yang <leoli@freescale.com>
[scottwood@freesacle.com: update commit message and rebase]
Signed-off-by: Scott Wood <scottwood@freescale.com>
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POWER8 allows read and write of the DSCR in userspace. We added
kernel emulation so applications could always use the instructions
regardless of the CPU type.
Unfortunately there are two SPRs for the DSCR and we only added
emulation for the privileged one. Add code to match the non
privileged one.
A simple test was created to verify the fix:
http://ozlabs.org/~anton/junkcode/user_dscr_test.c
Without the patch we get a SIGILL and it passes with the patch.
Signed-off-by: Anton Blanchard <anton@samba.org>
Cc: <stable@kernel.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
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This patch adds new POWER8 instruction encoding for reading
and clearing Branch History Rolling Buffer entries. The new
instruction 'mfbhrbe' (move from branch history rolling buffer
entry) is used to read BHRB buffer entries and instruction
'clrbhrb' (clear branch history rolling buffer) is used to
clear the entire buffer. The instruction 'clrbhrb' has straight
forward encoding. But the instruction encoding format for
reading the BHRB entries is like 'mfbhrbe RT, BHRBE' where it
takes two arguments, i.e the index for the BHRB buffer entry to
read and a general purpose register to put the value which was
read from the buffer entry.
Signed-off-by: Anshuman Khandual <khandual@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
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