linux.git/arch/powerpc/kernel/cpu_setup_power.S, branch v4.19 Linux kernel source tree powerpc/64s: Clear PCR on boot 2018-05-18T06:05:15+00:00 Michael Neuling mikey@neuling.org 2018-05-18T01:37:42+00:00 faf37c44a105f3608115785f17cbbf3500f8bc71 Clear the PCR (Processor Compatibility Register) on boot to ensure we are not running in a compatibility mode. We've seen this cause problems when a crash (and kdump) occurs while running compat mode guests. The kdump kernel then runs with the PCR set and causes problems. The symptom in the kdump kernel (also seen in petitboot after fast-reboot) is early userspace programs taking sigills on newer instructions (seen in libc). Signed-off-by: Michael Neuling <mikey@neuling.org> Cc: stable@vger.kernel.org Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> 
Clear the PCR (Processor Compatibility Register) on boot to ensure we
are not running in a compatibility mode.

We've seen this cause problems when a crash (and kdump) occurs while
running compat mode guests. The kdump kernel then runs with the PCR
set and causes problems. The symptom in the kdump kernel (also seen in
petitboot after fast-reboot) is early userspace programs taking
sigills on newer instructions (seen in libc).

Signed-off-by: Michael Neuling <mikey@neuling.org>
Cc: stable@vger.kernel.org
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Merge branch 'fixes' into next 2018-01-21T12:21:14+00:00 Michael Ellerman mpe@ellerman.id.au 2018-01-21T12:21:14+00:00 ebf0b6a8b1e445d2be66087732aafcda12ab9f59 Merge our fixes branch from the 4.15 cycle. Unusually the fixes branch saw some significant features merged, notably the RFI flush patches, so we want the code in next to be tested against that, to avoid any surprises when the two are merged. There's also some other work on the panic handling that was reverted in fixes and we now want to do properly in next, which would conflict. And we also fix a few other minor merge conflicts. 
Merge our fixes branch from the 4.15 cycle.

Unusually the fixes branch saw some significant features merged,
notably the RFI flush patches, so we want the code in next to be
tested against that, to avoid any surprises when the two are merged.

There's also some other work on the panic handling that was reverted
in fixes and we now want to do properly in next, which would conflict.

And we also fix a few other minor merge conflicts.
powerpc/64s: Improve local TLB flush for boot and MCE on POWER9 2018-01-17T13:40:31+00:00 Nicholas Piggin npiggin@gmail.com 2017-12-23T15:15:50+00:00 d4748276ae14ce951a3254852dddc3675797c277 There are several cases outside the normal address space management where a CPU's entire local TLB is to be flushed: 1. Booting the kernel, in case something has left stale entries in the TLB (e.g., kexec). 2. Machine check, to clean corrupted TLB entries. One other place where the TLB is flushed, is waking from deep idle states. The flush is a side-effect of calling ->cpu_restore with the intention of re-setting various SPRs. The flush itself is unnecessary because in the first case, the TLB should not acquire new corrupted TLB entries as part of sleep/wake (though they may be lost). This type of TLB flush is coded inflexibly, several times for each CPU type, and they have a number of problems with ISA v3.0B: - The current radix mode of the MMU is not taken into account, it is always done as a hash flushn For IS=2 (LPID-matching flush from host) and IS=3 with HV=0 (guest kernel flush), tlbie(l) is undefined if the R field does not match the current radix mode. - ISA v3.0B hash must flush the partition and process table caches as well. - ISA v3.0B radix must flush partition and process scoped translations, partition and process table caches, and also the page walk cache. So consolidate the flushing code and implement it in C and inline asm under the mm/ directory with the rest of the flush code. Add ISA v3.0B cases for radix and hash, and use the radix flush in radix environment. Provide a way for IS=2 (LPID flush) to specify the radix mode of the partition. Have KVM pass in the radix mode of the guest. Take out the flushes from early cputable/dt_cpu_ftrs detection hooks, and move it later in the boot process after, the MMU registers are set up and before relocation is first turned on. The TLB flush is no longer called when restoring from deep idle states. This was not be done as a separate step because booting secondaries uses the same cpu_restore as idle restore, which needs the TLB flush. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> 
There are several cases outside the normal address space management
where a CPU's entire local TLB is to be flushed:

  1. Booting the kernel, in case something has left stale entries in
     the TLB (e.g., kexec).

  2. Machine check, to clean corrupted TLB entries.

One other place where the TLB is flushed, is waking from deep idle
states. The flush is a side-effect of calling ->cpu_restore with the
intention of re-setting various SPRs. The flush itself is unnecessary
because in the first case, the TLB should not acquire new corrupted
TLB entries as part of sleep/wake (though they may be lost).

This type of TLB flush is coded inflexibly, several times for each CPU
type, and they have a number of problems with ISA v3.0B:

- The current radix mode of the MMU is not taken into account, it is
  always done as a hash flushn For IS=2 (LPID-matching flush from host)
  and IS=3 with HV=0 (guest kernel flush), tlbie(l) is undefined if
  the R field does not match the current radix mode.

- ISA v3.0B hash must flush the partition and process table caches as
  well.

- ISA v3.0B radix must flush partition and process scoped translations,
  partition and process table caches, and also the page walk cache.

So consolidate the flushing code and implement it in C and inline asm
under the mm/ directory with the rest of the flush code. Add ISA v3.0B
cases for radix and hash, and use the radix flush in radix environment.

Provide a way for IS=2 (LPID flush) to specify the radix mode of the
partition. Have KVM pass in the radix mode of the guest.

Take out the flushes from early cputable/dt_cpu_ftrs detection hooks,
and move it later in the boot process after, the MMU registers are set
up and before relocation is first turned on.

The TLB flush is no longer called when restoring from deep idle states.
This was not be done as a separate step because booting secondaries
uses the same cpu_restore as idle restore, which needs the TLB flush.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
powerpc/64s: Initialize ISAv3 MMU registers before setting partition table 2017-12-06T12:32:43+00:00 Nicholas Piggin npiggin@gmail.com 2017-12-06T08:21:14+00:00 371b80447ff33ddac392c189cf884a5a3e18faeb kexec can leave MMU registers set when booting into a new kernel, the PIDR (Process Identification Register) in particular. The boot sequence does not zero PIDR, so it only gets set when CPUs first switch to a userspace processes (until then it's running a kernel thread with effective PID = 0). This leaves a window where a process table entry and page tables are set up due to user processes running on other CPUs, that happen to match with a stale PID. The CPU with that PID may cause speculative accesses that address quadrant 0 (aka userspace addresses), which will result in cached translations and PWC (Page Walk Cache) for that process, on a CPU which is not in the mm_cpumask and so they will not be invalidated properly. The most common result is the kernel hanging in infinite page fault loops soon after kexec (usually in schedule_tail, which is usually the first non-speculative quadrant 0 access to a new PID) due to a stale PWC. However being a stale translation error, it could result in anything up to security and data corruption problems. Fix this by zeroing out PIDR at boot and kexec. Fixes: 7e381c0ff618 ("powerpc/mm/radix: Add mmu context handling callback for radix") Cc: stable@vger.kernel.org # v4.7+ Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> 
kexec can leave MMU registers set when booting into a new kernel,
the PIDR (Process Identification Register) in particular. The boot
sequence does not zero PIDR, so it only gets set when CPUs first
switch to a userspace processes (until then it's running a kernel
thread with effective PID = 0).

This leaves a window where a process table entry and page tables are
set up due to user processes running on other CPUs, that happen to
match with a stale PID. The CPU with that PID may cause speculative
accesses that address quadrant 0 (aka userspace addresses), which will
result in cached translations and PWC (Page Walk Cache) for that
process, on a CPU which is not in the mm_cpumask and so they will not
be invalidated properly.

The most common result is the kernel hanging in infinite page fault
loops soon after kexec (usually in schedule_tail, which is usually the
first non-speculative quadrant 0 access to a new PID) due to a stale
PWC. However being a stale translation error, it could result in
anything up to security and data corruption problems.

Fix this by zeroing out PIDR at boot and kexec.

Fixes: 7e381c0ff618 ("powerpc/mm/radix: Add mmu context handling callback for radix")
Cc: stable@vger.kernel.org # v4.7+
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
powerpc/powernv: Fix local TLB flush for boot and MCE on POWER9 2017-07-11T02:53:53+00:00 Nicholas Piggin npiggin@gmail.com 2017-07-06T10:51:28+00:00 41d0c2ecde19cfe93071ed7b979a53ba60b12840 There are two cases outside the normal address space management where a CPU's local TLB is to be flushed: 1. Host boot; in case something has left stale entries in the TLB (e.g., kexec). 2. Machine check; to clean corrupted TLB entries. CPU state restore from deep idle states also flushes the TLB. However this seems to be a side effect of reusing the boot code to set CPU state, rather than a requirement itself. The current flushing has a number of problems with ISA v3.0B: - The current radix mode of the MMU is not taken into account. tlbiel is undefined if the R field does not match the current radix mode. - ISA v3.0B hash must flush the partition and process table caches. - ISA v3.0B radix must flush partition and process scoped translations, partition and process table caches, and also the page walk cache. Add POWER9 cases to handle these, with radix vs hash determined by the host MMU mode. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> 
There are two cases outside the normal address space management
where a CPU's local TLB is to be flushed:

  1. Host boot; in case something has left stale entries in the
     TLB (e.g., kexec).

  2. Machine check; to clean corrupted TLB entries.

CPU state restore from deep idle states also flushes the TLB.
However this seems to be a side effect of reusing the boot code to set
CPU state, rather than a requirement itself.

The current flushing has a number of problems with ISA v3.0B:

- The current radix mode of the MMU is not taken into account. tlbiel
  is undefined if the R field does not match the current radix mode.

- ISA v3.0B hash must flush the partition and process table caches.

- ISA v3.0B radix must flush partition and process scoped translations,
  partition and process table caches, and also the page walk cache.

Add POWER9 cases to handle these, with radix vs hash determined by the
host MMU mode.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
powerpc/64s: Power9 has no LPCR[VRMASD] field so don't set it 2017-05-03T10:45:55+00:00 Nicholas Piggin npiggin@gmail.com 2017-04-18T19:12:17+00:00 700b7eadd5625d22b8235fb21259b3d7d564c000 Power9/ISAv3 has no VRMASD field in LPCR, we shouldn't be setting reserved bits, so don't set them on Power9. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> 
Power9/ISAv3 has no VRMASD field in LPCR, we shouldn't be setting reserved bits,
so don't set them on Power9.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
powerpc/64s: Revert setting of LPCR[LPES] on POWER9 2017-04-19T10:00:17+00:00 Nicholas Piggin npiggin@gmail.com 2017-04-18T19:12:16+00:00 8d1b48ef580097e111c2644e6fc6041b9784d218 The XIVE enablement patches included a change to set the LPES (Logical Partitioning Environment Selector) bit (bit # 3) in LPCR (Logical Partitioning Control Register) on POWER9 hosts. This bit sets external interrupts to guest delivery mode, which uses SRR0/1. The host's EE interrupt handler is written to expect HSRR0/1 (for earlier CPUs). This should be fine because XIVE is configured not to deliver EEs to the host (Hypervisor Virtulization Interrupt is used instead) so the EE handler should never be executed. However a bug in interrupt controller code, hardware, or odd configuration of a simulator could result in the host getting an EE incorrectly. Keeping the EE delivery mode matching the host EE handler prevents strange crashes due to using the wrong exception registers. KVM will configure the LPCR to set LPES prior to running a guest so that EEs are delivered to the guest using SRR0/1. Fixes: 08a1e650cc ("powerpc: Fixup LPCR:PECE and HEIC setting on POWER9") Signed-off-by: Nicholas Piggin <npiggin@gmail.com> [mpe: Massage change log to avoid referring to LPES0 which is now renamed LPES] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> 
The XIVE enablement patches included a change to set the LPES (Logical
Partitioning Environment Selector) bit (bit # 3) in LPCR (Logical Partitioning
Control Register) on POWER9 hosts. This bit sets external interrupts to guest
delivery mode, which uses SRR0/1. The host's EE interrupt handler is written to
expect HSRR0/1 (for earlier CPUs). This should be fine because XIVE is
configured not to deliver EEs to the host (Hypervisor Virtulization Interrupt is
used instead) so the EE handler should never be executed.

However a bug in interrupt controller code, hardware, or odd configuration of a
simulator could result in the host getting an EE incorrectly. Keeping the EE
delivery mode matching the host EE handler prevents strange crashes due to using
the wrong exception registers.

KVM will configure the LPCR to set LPES prior to running a guest so that EEs are
delivered to the guest using SRR0/1.

Fixes: 08a1e650cc ("powerpc: Fixup LPCR:PECE and HEIC setting on POWER9")
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
[mpe: Massage change log to avoid referring to LPES0 which is now renamed LPES]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
powerpc: Fixup LPCR:PECE and HEIC setting on POWER9 2017-04-10T11:43:17+00:00 Benjamin Herrenschmidt benh@kernel.crashing.org 2017-04-05T07:54:55+00:00 08a1e650cc631ccc8cfe670beb38b2f9c58402cd We need to set LPES in order for normal external interrupts (0x500) to be directed to the guest while running in guest state. We also need HEIC set to prevent them to be sent to the host while in host state. With XIVE the host never gets one of these and wouldn't know how to handle it. All host external interrupts come in via the new hypervisor virtualization interrupts vector. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> 
We need to set LPES in order for normal external interrupts (0x500)
to be directed to the guest while running in guest state.

We also need HEIC set to prevent them to be sent to the host while
in host state.

With XIVE the host never gets one of these and wouldn't know how to
handle it. All host external interrupts come in via the new
hypervisor virtualization interrupts vector.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
powerpc/mm/hash: Always clear UPRT and Host Radix bits when setting up CPU 2017-02-22T21:26:15+00:00 Aneesh Kumar K.V aneesh.kumar@linux.vnet.ibm.com 2017-02-22T05:12:02+00:00 fda2d27db6eae5c2468f9e4657539b72bbc238bb We will set LPCR with correct value for radix during int. This make sure we start with a sanitized value of LPCR. In case of kexec, cpus can have LPCR value based on the previous translation mode we were running. Fixes: fe036a0605d60 ("powerpc/64/kexec: Fix MMU cleanup on radix") Cc: stable@vger.kernel.org # v4.9+ Acked-by: Michael Neuling <mikey@neuling.org> Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> 
We will set LPCR with correct value for radix during int. This make sure we
start with a sanitized value of LPCR. In case of kexec, cpus can have LPCR
value based on the previous translation mode we were running.

Fixes: fe036a0605d60 ("powerpc/64/kexec: Fix MMU cleanup on radix")
Cc: stable@vger.kernel.org # v4.9+
Acked-by: Michael Neuling <mikey@neuling.org>
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Merge tag 'powerpc-4.10-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux 2016-12-16T17:26:42+00:00 Linus Torvalds torvalds@linux-foundation.org 2016-12-16T17:26:42+00:00 de399813b521ea7e38bbfb5e5b620b5e202e5783 Pull powerpc updates from Michael Ellerman: "Highlights include: - Support for the kexec_file_load() syscall, which is a prereq for secure and trusted boot. - Prevent kernel execution of userspace on P9 Radix (similar to SMEP/PXN). - Sort the exception tables at build time, to save time at boot, and store them as relative offsets to save space in the kernel image & memory. - Allow building the kernel with thin archives, which should allow us to build an allyesconfig once some other fixes land. - Build fixes to allow us to correctly rebuild when changing the kernel endian from big to little or vice versa. - Plumbing so that we can avoid doing a full mm TLB flush on P9 Radix. - Initial stack protector support (-fstack-protector). - Support for dumping the radix (aka. Linux) and hash page tables via debugfs. - Fix an oops in cxl coredump generation when cxl_get_fd() is used. - Freescale updates from Scott: "Highlights include 8xx hugepage support, qbman fixes/cleanup, device tree updates, and some misc cleanup." - Many and varied fixes and minor enhancements as always. Thanks to: Alexey Kardashevskiy, Andrew Donnellan, Aneesh Kumar K.V, Anshuman Khandual, Anton Blanchard, Balbir Singh, Bartlomiej Zolnierkiewicz, Christophe Jaillet, Christophe Leroy, Denis Kirjanov, Elimar Riesebieter, Frederic Barrat, Gautham R. Shenoy, Geliang Tang, Geoff Levand, Jack Miller, Johan Hovold, Lars-Peter Clausen, Libin, Madhavan Srinivasan, Michael Neuling, Nathan Fontenot, Naveen N. Rao, Nicholas Piggin, Pan Xinhui, Peter Senna Tschudin, Rashmica Gupta, Rui Teng, Russell Currey, Scott Wood, Simon Guo, Suraj Jitindar Singh, Thiago Jung Bauermann, Tobias Klauser, Vaibhav Jain" [ And thanks to Michael, who took time off from a new baby to get this pull request done. - Linus ] * tag 'powerpc-4.10-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: (174 commits) powerpc/fsl/dts: add FMan node for t1042d4rdb powerpc/fsl/dts: add sg_2500_aqr105_phy4 alias on t1024rdb powerpc/fsl/dts: add QMan and BMan nodes on t1024 powerpc/fsl/dts: add QMan and BMan nodes on t1023 soc/fsl/qman: test: use DEFINE_SPINLOCK() powerpc/fsl-lbc: use DEFINE_SPINLOCK() powerpc/8xx: Implement support of hugepages powerpc: get hugetlbpage handling more generic powerpc: port 64 bits pgtable_cache to 32 bits powerpc/boot: Request no dynamic linker for boot wrapper soc/fsl/bman: Use resource_size instead of computation soc/fsl/qe: use builtin_platform_driver powerpc/fsl_pmc: use builtin_platform_driver powerpc/83xx/suspend: use builtin_platform_driver powerpc/ftrace: Fix the comments for ftrace_modify_code powerpc/perf: macros for power9 format encoding powerpc/perf: power9 raw event format encoding powerpc/perf: update attribute_group data structure powerpc/perf: factor out the event format field powerpc/mm/iommu, vfio/spapr: Put pages on VFIO container shutdown ... 
Pull powerpc updates from Michael Ellerman:
 "Highlights include:

   - Support for the kexec_file_load() syscall, which is a prereq for
     secure and trusted boot.

   - Prevent kernel execution of userspace on P9 Radix (similar to
     SMEP/PXN).

   - Sort the exception tables at build time, to save time at boot, and
     store them as relative offsets to save space in the kernel image &
     memory.

   - Allow building the kernel with thin archives, which should allow us
     to build an allyesconfig once some other fixes land.

   - Build fixes to allow us to correctly rebuild when changing the
     kernel endian from big to little or vice versa.

   - Plumbing so that we can avoid doing a full mm TLB flush on P9
     Radix.

   - Initial stack protector support (-fstack-protector).

   - Support for dumping the radix (aka. Linux) and hash page tables via
     debugfs.

   - Fix an oops in cxl coredump generation when cxl_get_fd() is used.

   - Freescale updates from Scott: "Highlights include 8xx hugepage
     support, qbman fixes/cleanup, device tree updates, and some misc
     cleanup."

   - Many and varied fixes and minor enhancements as always.

  Thanks to:
    Alexey Kardashevskiy, Andrew Donnellan, Aneesh Kumar K.V, Anshuman
    Khandual, Anton Blanchard, Balbir Singh, Bartlomiej Zolnierkiewicz,
    Christophe Jaillet, Christophe Leroy, Denis Kirjanov, Elimar
    Riesebieter, Frederic Barrat, Gautham R. Shenoy, Geliang Tang, Geoff
    Levand, Jack Miller, Johan Hovold, Lars-Peter Clausen, Libin,
    Madhavan Srinivasan, Michael Neuling, Nathan Fontenot, Naveen N.
    Rao, Nicholas Piggin, Pan Xinhui, Peter Senna Tschudin, Rashmica
    Gupta, Rui Teng, Russell Currey, Scott Wood, Simon Guo, Suraj
    Jitindar Singh, Thiago Jung Bauermann, Tobias Klauser, Vaibhav Jain"

[ And thanks to Michael, who took time off from a new baby to get this
  pull request done.   - Linus ]

* tag 'powerpc-4.10-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: (174 commits)
  powerpc/fsl/dts: add FMan node for t1042d4rdb
  powerpc/fsl/dts: add sg_2500_aqr105_phy4 alias on t1024rdb
  powerpc/fsl/dts: add QMan and BMan nodes on t1024
  powerpc/fsl/dts: add QMan and BMan nodes on t1023
  soc/fsl/qman: test: use DEFINE_SPINLOCK()
  powerpc/fsl-lbc: use DEFINE_SPINLOCK()
  powerpc/8xx: Implement support of hugepages
  powerpc: get hugetlbpage handling more generic
  powerpc: port 64 bits pgtable_cache to 32 bits
  powerpc/boot: Request no dynamic linker for boot wrapper
  soc/fsl/bman: Use resource_size instead of computation
  soc/fsl/qe: use builtin_platform_driver
  powerpc/fsl_pmc: use builtin_platform_driver
  powerpc/83xx/suspend: use builtin_platform_driver
  powerpc/ftrace: Fix the comments for ftrace_modify_code
  powerpc/perf: macros for power9 format encoding
  powerpc/perf: power9 raw event format encoding
  powerpc/perf: update attribute_group data structure
  powerpc/perf: factor out the event format field
  powerpc/mm/iommu, vfio/spapr: Put pages on VFIO container shutdown
  ...