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2021-06-25powerpc/64s: avoid reloading (H)SRR registers if they are still validNicholas Piggin1-0/+4
When an interrupt is taken, the SRR registers are set to return to where it left off. Unless they are modified in the meantime, or the return address or MSR are modified, there is no need to reload these registers when returning from interrupt. Introduce per-CPU flags that track the validity of SRR and HSRR registers. These are cleared when returning from interrupt, when using the registers for something else (e.g., OPAL calls), when adjusting the return address or MSR of a context, and when context switching (which changes the return address and MSR). This improves the performance of interrupt returns. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> [mpe: Fold in fixup patch from Nick] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20210617155116.2167984-5-npiggin@gmail.com
2021-05-02powerpc/powernv: remove the nvlink supportChristoph Hellwig1-2/+0
This code was only used by the vfio-nvlink2 code, which itself had no proper use. Drop this huge chunk of code build into every powernv or generic build. Signed-off-by: Christoph Hellwig <hch@lst.de> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20210326061311.1497642-3-hch@lst.de
2019-11-13powerpc/powernv: Add OPAL API interface to access secure variableNayna Jain1-0/+3
The X.509 certificates trusted by the platform and required to secure boot the OS kernel are wrapped in secure variables, which are controlled by OPAL. This patch adds firmware/kernel interface to read and write OPAL secure variables based on the unique key. This support can be enabled using CONFIG_OPAL_SECVAR. Signed-off-by: Claudio Carvalho <cclaudio@linux.ibm.com> Signed-off-by: Nayna Jain <nayna@linux.ibm.com> Signed-off-by: Eric Richter <erichte@linux.ibm.com> [mpe: Make secvar_ops __ro_after_init, only build opal-secvar.c if PPC_SECURE_BOOT=y] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/1573441836-3632-2-git-send-email-nayna@linux.ibm.com
2019-09-14powerpc/opal: add MPIPL interface definitionsHari Bathini1-0/+3
MPIPL is Memory Preserving IPL supported from POWER9. This enables the kernel to reset the system with memory 'preserved'. Also, it supports copying memory from a source address to some destination address during MPIPL boot. Add MPIPL interface definitions here to leverage these f/w features in adding FADump support for PowerNV platform. Signed-off-by: Hari Bathini <hbathini@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/156821340710.5656.10071829040515662624.stgit@hbathini.in.ibm.com
2019-09-12powerpc/xive: Fix bogus error code returned by OPALGreg Kurz1-1/+1
There's a bug in skiboot that causes the OPAL_XIVE_ALLOCATE_IRQ call to return the 32-bit value 0xffffffff when OPAL has run out of IRQs. Unfortunatelty, OPAL return values are signed 64-bit entities and errors are supposed to be negative. If that happens, the linux code confusingly treats 0xffffffff as a valid IRQ number and panics at some point. A fix was recently merged in skiboot: e97391ae2bb5 ("xive: fix return value of opal_xive_allocate_irq()") but we need a workaround anyway to support older skiboots already in the field. Internally convert 0xffffffff to OPAL_RESOURCE which is the usual error returned upon resource exhaustion. Cc: stable@vger.kernel.org # v4.12+ Signed-off-by: Greg Kurz <groug@kaod.org> Reviewed-by: Cédric Le Goater <clg@kaod.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/156821713818.1985334.14123187368108582810.stgit@bahia.lan
2019-07-01powerpc/powernv: remove the unused pnv_pci_set_p2p functionChristoph Hellwig1-1/+0
This function has never been used anywhere in the kernel tree since it was added to the tree. We also now have proper PCIe P2P APIs in the core kernel, and any new P2P support should be using those. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-05-03powerpc/hmi: Fix kernel hang when TB is in error state.Mahesh Salgaonkar1-0/+1
On TOD/TB errors timebase register stops/freezes until HMI error recovery gets TOD/TB back into running state. On successful recovery, TB starts running again and udelay() that relies on TB value continues to function properly. But in case when HMI fails to recover from TOD/TB errors, the TB register stay freezed. With TB not running the __delay() function keeps looping and never return. If __delay() is called while in panic path then system hangs and never reboots after panic. Signed-off-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-04-30Merge branch 'topic/ppc-kvm' into nextMichael Ellerman1-0/+3
Merge our topic branch shared with KVM. In particular this includes the rewrite of the idle code into C.
2019-04-20powerpc/powernv: Squash sparse warnings in opal-call.cAndrew Donnellan1-0/+2
sparse complains a lot about opal-call.c: arch/powerpc/platforms/powernv/opal-call.c:128:1: warning: symbol 'opal_invalid_call' was not declared. Should it be static? arch/powerpc/platforms/powernv/opal-call.c:129:1: warning: symbol 'opal_console_write' was not declared. Should it be static? arch/powerpc/platforms/powernv/opal-call.c:130:1: warning: symbol 'opal_console_read' was not declared. Should it be static? Those symbols are forward declared in opal.h, but we can't include that because the function signatures in opal.h are different. So instead, just add an extra forward declaration to the OPAL_CALL macro to shut sparse up. Signed-off-by: Andrew Donnellan <andrew.donnellan@au1.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-04-11powerpc/xive: add OPAL extensions for the XIVE native exploitation supportCédric Le Goater1-0/+3
The support for XIVE native exploitation mode in Linux/KVM needs a couple more OPAL calls to get and set the state of the XIVE internal structures being used by a sPAPR guest. Signed-off-by: Cédric Le Goater <clg@kaod.org> Reviewed-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-03-13powerpc/powernv: Fix compile without CONFIG_TRACEPOINTSAlexey Kardashevskiy1-0/+1
The functions returns s64 but the return statement is missing. This adds the missing return statement. Fixes: 75d9fc7fd94e ("powerpc/powernv: move OPAL call wrapper tracing and interrupt handling to C") Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-02-26powerpc/powernv: move OPAL call wrapper tracing and interrupt handling to CNicholas Piggin1-0/+283
The OPAL call wrapper gets interrupt disabling wrong. It disables interrupts just by clearing MSR[EE], which has two problems: - It doesn't call into the IRQ tracing subsystem, which means tracing across OPAL calls does not always notice IRQs have been disabled. - It doesn't go through the IRQ soft-mask code, which causes a minor bug. MSR[EE] can not be restored by saving the MSR then clearing MSR[EE], because a racing interrupt while soft-masked could clear MSR[EE] between the two steps. This can cause MSR[EE] to be incorrectly enabled when the OPAL call returns. Fortunately that should only result in another masked interrupt being taken to disable MSR[EE] again, but it's a bit sloppy. The existing code also saves MSR to PACA, which is not re-entrant if there is a nested OPAL call from different MSR contexts, which can happen these days with SRESET interrupts on bare metal. To fix these issues, move the tracing and IRQ handling code to C, and call into asm just for the low level call when everything is ready to go. Save the MSR on stack rather than PACA. Performance cost is kept to a minimum with a few optimisations: - The endian switch upon return is combined with the MSR restore, which avoids an expensive context synchronizing operation for LE kernels. This makes up for the additional mtmsrd to enable interrupts with local_irq_enable(). - blr is now used to return from the opal_* functions that are called as C functions, to avoid link stack corruption. This requires a skiboot fix as well to keep the call stack balanced. A NULL call is more costly after this, (410ns->430ns on POWER9), but OPAL calls are generally not performance critical at this scale. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>