Commit Graph

21046 Commits

Author SHA1 Message Date
Christophe Leroy
3978eb7851 powerpc/32: Add early stack overflow detection with VMAP stack.
To avoid recursive faults, stack overflow detection has to be
performed before writing in the stack in exception prologs.

Do it by checking the alignment. If the stack pointer alignment is
wrong, it means it is pointing to the following or preceding page.

Without VMAP stack, a stack overflow is catastrophic. With VMAP
stack, a stack overflow isn't destructive, so don't panic. Kill
the task with SIGSEGV instead.

A dedicated overflow stack is set up for each CPU.

  lkdtm: Performing direct entry EXHAUST_STACK
  lkdtm: Calling function with 512 frame size to depth 32 ...
  lkdtm: loop 32/32 ...
  lkdtm: loop 31/32 ...
  lkdtm: loop 30/32 ...
  lkdtm: loop 29/32 ...
  lkdtm: loop 28/32 ...
  lkdtm: loop 27/32 ...
  lkdtm: loop 26/32 ...
  lkdtm: loop 25/32 ...
  lkdtm: loop 24/32 ...
  lkdtm: loop 23/32 ...
  lkdtm: loop 22/32 ...
  lkdtm: loop 21/32 ...
  lkdtm: loop 20/32 ...
  Kernel stack overflow in process test[359], r1=c900c008
  Oops: Kernel stack overflow, sig: 6 [#1]
  BE PAGE_SIZE=4K MMU=Hash PowerMac
  Modules linked in:
  CPU: 0 PID: 359 Comm: test Not tainted 5.3.0-rc7+ #2225
  NIP:  c0622060 LR: c0626710 CTR: 00000000
  REGS: c0895f48 TRAP: 0000   Not tainted  (5.3.0-rc7+)
  MSR:  00001032 <ME,IR,DR,RI>  CR: 28004224  XER: 00000000
  GPR00: c0626ca4 c900c008 c783c000 c07335cc c900c010 c07335cc c900c0f0 c07335cc
  GPR08: c900c0f0 00000001 00000000 00000000 28008222 00000000 00000000 00000000
  GPR16: 00000000 00000000 10010128 10010000 b799c245 10010158 c07335cc 00000025
  GPR24: c0690000 c08b91d4 c068f688 00000020 c900c0f0 c068f668 c08b95b4 c08b91d4
  NIP [c0622060] format_decode+0x0/0x4d4
  LR [c0626710] vsnprintf+0x80/0x5fc
  Call Trace:
  [c900c068] [c0626ca4] vscnprintf+0x18/0x48
  [c900c078] [c007b944] vprintk_store+0x40/0x214
  [c900c0b8] [c007bf50] vprintk_emit+0x90/0x1dc
  [c900c0e8] [c007c5cc] printk+0x50/0x60
  [c900c128] [c03da5b0] recursive_loop+0x44/0x6c
  [c900c338] [c03da5c4] recursive_loop+0x58/0x6c
  [c900c548] [c03da5c4] recursive_loop+0x58/0x6c
  [c900c758] [c03da5c4] recursive_loop+0x58/0x6c
  [c900c968] [c03da5c4] recursive_loop+0x58/0x6c
  [c900cb78] [c03da5c4] recursive_loop+0x58/0x6c
  [c900cd88] [c03da5c4] recursive_loop+0x58/0x6c
  [c900cf98] [c03da5c4] recursive_loop+0x58/0x6c
  [c900d1a8] [c03da5c4] recursive_loop+0x58/0x6c
  [c900d3b8] [c03da5c4] recursive_loop+0x58/0x6c
  [c900d5c8] [c03da5c4] recursive_loop+0x58/0x6c
  [c900d7d8] [c03da5c4] recursive_loop+0x58/0x6c
  [c900d9e8] [c03da5c4] recursive_loop+0x58/0x6c
  [c900dbf8] [c03da5c4] recursive_loop+0x58/0x6c
  [c900de08] [c03da67c] lkdtm_EXHAUST_STACK+0x30/0x4c
  [c900de18] [c03da3e8] direct_entry+0xc8/0x140
  [c900de48] [c029fb40] full_proxy_write+0x64/0xcc
  [c900de68] [c01500f8] __vfs_write+0x30/0x1d0
  [c900dee8] [c0152cb8] vfs_write+0xb8/0x1d4
  [c900df08] [c0152f7c] ksys_write+0x58/0xe8
  [c900df38] [c0014208] ret_from_syscall+0x0/0x34
  --- interrupt: c01 at 0xf806664
      LR = 0x1000c868
  Instruction dump:
  4bffff91 80010014 7c832378 7c0803a6 38210010 4e800020 3d20c08a 3ca0c089
  8089a0cc 38a58f0c 38600001 4ba2d494 <9421ffe0> 7c0802a6 bfc10018 7c9f2378

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/1b89c121b4070c7ee99e4f22cc178f15a736b07b.1576916812.git.christophe.leroy@c-s.fr
2020-01-27 22:35:49 +11:00
Christophe Leroy
63289e7d3a powerpc: align stack to 2 * THREAD_SIZE with VMAP_STACK
In order to ease stack overflow detection, align
stack to 2 * THREAD_SIZE when using VMAP_STACK.
This allows overflow detection using a single bit check.

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/60e9ae86b7d2cdcf21468787076d345663648f46.1576916812.git.christophe.leroy@c-s.fr
2020-01-26 22:15:09 +11:00
Christophe Leroy
028474876f powerpc/32: prepare for CONFIG_VMAP_STACK
To support CONFIG_VMAP_STACK, the kernel has to activate Data MMU
Translation for accessing the stack. Before doing that it must save
SRR0, SRR1 and also DAR and DSISR when relevant, in order to not
loose them in case there is a Data TLB Miss once the translation is
reactivated.

This patch adds fields in thread struct for saving those registers.
It prepares entry_32.S to handle exception entry with
Data MMU Translation enabled and alters EXCEPTION_PROLOG macros to
save SRR0, SRR1, DAR and DSISR then reenables Data MMU.

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/a775a1fea60f190e0f63503463fb775310a2009b.1576916812.git.christophe.leroy@c-s.fr
2020-01-26 22:15:09 +11:00
Christophe Leroy
c9c84fd945 powerpc/32: add a macro to get and/or save DAR and DSISR on stack.
Refactor reading and saving of DAR and DSISR in exception vectors.

This will ease the implementation of VMAP stack.

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/1286b3e51b07727c6b4b05f2df9af3f9b1717fb5.1576916812.git.christophe.leroy@c-s.fr
2020-01-26 22:15:09 +11:00
Christophe Leroy
5ae8fabc64 powerpc/32: move MSR_PR test into EXCEPTION_PROLOG_0
In order to simplify  VMAP stack implementation, move
MSR_PR test into EXCEPTION_PROLOG_0.

This requires to not modify cr0 between EXCEPTION_PROLOG_0
and EXCEPTION_PROLOG_1.

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/5c8b5bba692b92654dbd363a229a1ba91db725bb.1576916812.git.christophe.leroy@c-s.fr
2020-01-26 22:15:09 +11:00
Christophe Leroy
1ca9db5b65 powerpc/32: save DEAR/DAR before calling handle_page_fault
handle_page_fault() is the only function that save DAR/DEAR itself.

Save DAR/DEAR before calling handle_page_fault() to prepare for
VMAP stack which will require to save even before.

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/3a4d58d378091086f00fde42b59610c80289e120.1576916812.git.christophe.leroy@c-s.fr
2020-01-26 22:15:09 +11:00
Christophe Leroy
1f1c4d0122 powerpc/32: Add EXCEPTION_PROLOG_0 in head_32.h
This patch creates a macro for the very first part of
exception prolog, this will help when implementing
CONFIG_VMAP_STACK

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/2249fe62f481121a180e9655ad2b998093f318f3.1576916812.git.christophe.leroy@c-s.fr
2020-01-26 22:15:08 +11:00
Christophe Leroy
39bccfd164 powerpc/32: replace MTMSRD() by mtmsr
On PPC32, MTMSRD() is simply defined as mtmsr.

Replace MTMSRD(reg) by mtmsr reg in files dedicated to PPC32,
this makes the code less obscure.

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/22469e78230edea3dbd0c79a555d73124f6c6d93.1576916812.git.christophe.leroy@c-s.fr
2020-01-26 22:15:08 +11:00
Michael Bringmann
f1dbc1c5c7 powerpc/pseries/lparcfg: Fix display of Maximum Memory
Correct overflow problem in calculation and display of Maximum Memory
value to syscfg.

Signed-off-by: Michael Bringmann <mwb@linux.ibm.com>
[mpe: Only n_lmbs needs casting to unsigned long]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/5577aef8-1d5a-ca95-ff0a-9c7b5977e5bf@linux.ibm.com
2020-01-26 00:11:37 +11:00
Jordan Niethe
736bcdd3a9 powerpc/mm: Remove kvm radix prefetch workaround for Power9 DD2.2
Commit a25bd72bad ("powerpc/mm/radix: Workaround prefetch issue with
KVM") introduced a number of workarounds as coming out of a guest with
the mmu enabled would make the cpu would start running in hypervisor
state with the PID value from the guest. The cpu will then start
prefetching for the hypervisor with that PID value.

In Power9 DD2.2 the cpu behaviour was modified to fix this. When
accessing Quadrant 0 in hypervisor mode with LPID != 0 prefetching will
not be performed. This means that we can get rid of the workarounds for
Power9 DD2.2 and later revisions. Add a new cpu feature
CPU_FTR_P9_RADIX_PREFETCH_BUG to indicate if the workarounds are needed.

Signed-off-by: Jordan Niethe <jniethe5@gmail.com>
Acked-by: Paul Mackerras <paulus@ozlabs.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20191206031722.25781-1-jniethe5@gmail.com
2020-01-26 00:11:37 +11:00
Vaibhav Jain
5649607a8d powerpc/papr_scm: Fix leaking 'bus_desc.provider_name' in some paths
String 'bus_desc.provider_name' allocated inside
papr_scm_nvdimm_init() will leaks in case call to
nvdimm_bus_register() fails or when papr_scm_remove() is called.

This minor patch ensures that 'bus_desc.provider_name' is freed in
error path for nvdimm_bus_register() as well as in papr_scm_remove().

Fixes: b5beae5e22 ("powerpc/pseries: Add driver for PAPR SCM regions")
Signed-off-by: Vaibhav Jain <vaibhav@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200122155140.120429-1-vaibhav@linux.ibm.com
2020-01-26 00:11:37 +11:00
Sukadev Bhattiprolu
493a55f1e7 powerpc/xmon: Fix compile error in print_insn* functions
Fix couple of compile errors I stumbled upon with CONFIG_XMON=y and
CONFIG_XMON_DISASSEMBLY=n

Signed-off-by: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200123010455.GA15080@us.ibm.com
2020-01-26 00:11:35 +11:00
Christophe Leroy
def0bfdbd6 powerpc: use probe_user_read() and probe_user_write()
Instead of opencoding, use probe_user_read() to failessly read
a user location and probe_user_write() for writing to user.

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/e041f5eedb23f09ab553be8a91c3de2087147320.1579800517.git.christophe.leroy@c-s.fr
2020-01-26 00:11:35 +11:00
Chen Zhou
1e3531982e powerpc/maple: Fix comparing pointer to 0
Fixes coccicheck warning:
  arch/powerpc/platforms/maple/setup.c:232:15-16:
	WARNING comparing pointer to 0

Compare pointer-typed values to NULL rather than 0.

Signed-off-by: Chen Zhou <chenzhou10@huawei.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200121013153.9937-1-chenzhou10@huawei.com
2020-01-26 00:11:35 +11:00
Tyrel Datwyler
aff8c8242b powerpc/pseries/vio: Fix iommu_table use-after-free refcount warning
Commit e5afdf9dd5 ("powerpc/vfio_spapr_tce: Add reference counting to
iommu_table") missed an iommu_table allocation in the pseries vio code.
The iommu_table is allocated with kzalloc and as a result the associated
kref gets a value of zero. This has the side effect that during a DLPAR
remove of the associated virtual IOA the iommu_tce_table_put() triggers
a use-after-free underflow warning.

Call Trace:
[c0000002879e39f0] [c00000000071ecb4] refcount_warn_saturate+0x184/0x190
(unreliable)
[c0000002879e3a50] [c0000000000500ac] iommu_tce_table_put+0x9c/0xb0
[c0000002879e3a70] [c0000000000f54e4] vio_dev_release+0x34/0x70
[c0000002879e3aa0] [c00000000087cfa4] device_release+0x54/0xf0
[c0000002879e3b10] [c000000000d64c84] kobject_cleanup+0xa4/0x240
[c0000002879e3b90] [c00000000087d358] put_device+0x28/0x40
[c0000002879e3bb0] [c0000000007a328c] dlpar_remove_slot+0x15c/0x250
[c0000002879e3c50] [c0000000007a348c] remove_slot_store+0xac/0xf0
[c0000002879e3cd0] [c000000000d64220] kobj_attr_store+0x30/0x60
[c0000002879e3cf0] [c0000000004ff13c] sysfs_kf_write+0x6c/0xa0
[c0000002879e3d10] [c0000000004fde4c] kernfs_fop_write+0x18c/0x260
[c0000002879e3d60] [c000000000410f3c] __vfs_write+0x3c/0x70
[c0000002879e3d80] [c000000000415408] vfs_write+0xc8/0x250
[c0000002879e3dd0] [c0000000004157dc] ksys_write+0x7c/0x120
[c0000002879e3e20] [c00000000000b278] system_call+0x5c/0x68

Further, since the refcount was always zero the iommu_tce_table_put()
fails to call the iommu_table release function resulting in a leak.

Fix this issue be initilizing the iommu_table kref immediately after
allocation.

Fixes: e5afdf9dd5 ("powerpc/vfio_spapr_tce: Add reference counting to iommu_table")
Signed-off-by: Tyrel Datwyler <tyreld@linux.ibm.com>
Reviewed-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/1579558202-26052-1-git-send-email-tyreld@linux.ibm.com
2020-01-26 00:11:35 +11:00
Aneesh Kumar K.V
7e6f8cbc5e powerpc/papr_scm: Don't enable direct map for a region by default
Setting ND_REGION_PAGEMAP flag implies namespace mode defaults to fsdax mode.
This also means kernel ends up creating struct page backing for these namspace
ranges. With large namespaces that is not the right thing to do. We
should let the user select the mode he/she wants the namespace to be created
with.

Hence disable ND_REGION_PAGEMAP for papr_scm regions. We still keep the flag for
of_pmem because it supports only small persistent memory regions.

This is similar to what is done for x86 with commit
commit: 004f1afbe1 ("libnvdimm, pmem: direct map legacy pmem by default")

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200108064647.169637-1-aneesh.kumar@linux.ibm.com
2020-01-26 00:11:32 +11:00
Greg Kurz
b059c63620 powerpc/xive: Drop extern qualifiers from header function prototypes
As reported by ./scripts/checkpatch.pl --strict:

CHECK: extern prototypes should be avoided in .h files

Signed-off-by: Greg Kurz <groug@kaod.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/157384145834.181768.944827793193636924.stgit@bahia.lan
2020-01-23 21:31:23 +11:00
Greg Kurz
6a3163212f KVM: PPC: Book3S HV: XIVE: Fix typo in comment
Signed-off-by: Greg Kurz <groug@kaod.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/156219139988.578018.1046848908285019838.stgit@bahia.lan
2020-01-23 21:31:23 +11:00
Oliver O'Halloran
946743d035 powernv/pci: Move pnv_pci_dma_bus_setup() to pci-ioda.c
This is only used in pci-ioda.c so move it there and rename it to match.

Signed-off-by: Oliver O'Halloran <oohall@gmail.com>
Reviewed-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200110070207.439-6-oohall@gmail.com
2020-01-23 21:31:22 +11:00
Oliver O'Halloran
0a25d9c401 powernv/pci: Fold pnv_pci_dma_dev_setup() into the pci-ioda.c version
pnv_pci_dma_dev_setup() does nothing but call the phb->dma_dev_setup()
callback, if one exists. That callback is only set for normal PCIe PHBs so
we can remove the layer of indirection and use the ioda version in
the pci_controller_ops.

Signed-off-by: Oliver O'Halloran <oohall@gmail.com>
Reviewed-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200110070207.439-5-oohall@gmail.com
2020-01-23 21:31:22 +11:00
Oliver O'Halloran
965c94f309 powerpc/iov: Move VF pdev fixup into pcibios_fixup_iov()
An ioda_pe for each VF is allocated in pnv_pci_sriov_enable() before
the pci_dev for the VF is created. We need to set the pe->pdev pointer
at some point after the pci_dev is created. Currently we do that in:

pcibios_bus_add_device()
	pnv_pci_dma_dev_setup() (via phb->ops.dma_dev_setup)
		/* fixup is done here */
		pnv_pci_ioda_dma_dev_setup() (via pnv_phb->dma_dev_setup)

The fixup needs to be done before setting up DMA for for the VF's PE,
but there's no real reason to delay it until this point. Move the
fixup into pnv_pci_ioda_fixup_iov() so the ordering is:

	pcibios_add_device()
		pnv_pci_ioda_fixup_iov() (via ppc_md.pcibios_fixup_sriov)

	pcibios_bus_add_device()
		...

This isn't strictly required, but it's a slightly more logical place
to do the fixup and it simplifies pnv_pci_dma_dev_setup().

Signed-off-by: Oliver O'Halloran <oohall@gmail.com>
Reviewed-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200110070207.439-4-oohall@gmail.com
2020-01-23 21:31:22 +11:00
Oliver O'Halloran
ac11720195 powernv/pci: Remove dma_dev_setup() for NPU PHBs
The pnv_pci_dma_dev_setup() only does something when:

1) There PHB contains VFs, or
2) The PHB defines a dma_dev_setup() callback in the pnv_phb structure.

Neither is true for NPU PHBs so there's no reason to set the callback.

Reviewed-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Signed-off-by: Oliver O'Halloran <oohall@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200110070207.439-3-oohall@gmail.com
2020-01-23 21:31:21 +11:00
Oliver O'Halloran
3ab3f3c9df powerpc/pci: Fold pcibios_setup_device() into pcibios_bus_add_device()
pcibios_bus_add_device() is the only caller of pcibios_setup_device().
Fold them together since there's no real reason to keep them separate.

Signed-off-by: Oliver O'Halloran <oohall@gmail.com>
Reviewed-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200110070207.439-2-oohall@gmail.com
2020-01-23 21:31:21 +11:00
Oliver O'Halloran
37f6f8e88c powerpc/powernv: Allow manually invoking special reboots
OPAL provides several different kinds of reboot for the kernel to use,
namely forcing a full reboot, platform error reboot and MPIPL. Right now
triggering the alternative resets requires some ad-hoc method such as
triggering a kernel crash and hoping the stars align. It's sometimes handy
to be able to trigger one of these resets directly, so add a way to do
that.

Signed-off-by: Oliver O'Halloran <oohall@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20191101085522.3055-2-oohall@gmail.com
2020-01-23 21:31:21 +11:00
Oliver O'Halloran
2d9b332d99 powerpc/xmon: Allow passing an argument to ppc_md.restart()
On PowerNV a few different kinds of reboot are supported. We'd like to be
able to exercise these from xmon so allow 'zr' to take an argument, and
pass that to the ppc_md.restart() function.

Signed-off-by: Oliver O'Halloran <oohall@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20191101085522.3055-1-oohall@gmail.com
2020-01-23 21:31:21 +11:00
Oliver O'Halloran
846a17a53a powerpc/powernv: Use common code for the symbol_map export
Long before we had a generic way for firmware to export memory ranges of
interest we added a special case for the skiboot symbol map. The code is
pretty much identical to the generic export so re-use the code.

Signed-off-by: Oliver O'Halloran <oohall@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20191101062611.32610-2-oohall@gmail.com
2020-01-23 21:31:21 +11:00
Oliver O'Halloran
db93361260 powerpc/powernv: Rework exports to support subnodes
Originally we only had a handful of exported memory ranges, but we'd to
export the per-core trace buffers. This results in a lot of files in the
exports directory which is a but unfortunate. We can clean things up a bit
by turning subnodes into subdirectories of the exports directory.

Signed-off-by: Oliver O'Halloran <oohall@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20191101062611.32610-1-oohall@gmail.com
2020-01-23 21:31:20 +11:00
Oliver O'Halloran
4e0942c030 powerpc/eeh: Only dump stack once if an MMIO loop is detected
Many drivers don't check for errors when they get a 0xFFs response from an
MMIO load. As a result after an EEH event occurs a driver can get stuck in
a polling loop unless it some kind of internal timeout logic.

Currently EEH tries to detect and report stuck drivers by dumping a stack
trace after eeh_dev_check_failure() is called EEH_MAX_FAILS times on an
already frozen PE. The value of EEH_MAX_FAILS was chosen so that a dump
would occur every few seconds if the driver was spinning in a loop. This
results in a lot of spurious stack traces in the kernel log.

Fix this by limiting it to printing one stack trace for each PE freeze. If
the driver is truely stuck the kernel's hung task detector is better suited
to reporting the probelm anyway.

Signed-off-by: Oliver O'Halloran <oohall@gmail.com>
Reviewed-by: Sam Bobroff <sbobroff@linux.ibm.com>
Tested-by: Sam Bobroff <sbobroff@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20191016012536.22588-1-oohall@gmail.com
2020-01-23 21:31:20 +11:00
Oliver O'Halloran
18697d2b08 powernv/pci: Add a debugfs entry to dump PHB's IODA PE state
Add a debugfs entry to dump the state of the active IODA PEs. The IODA
PE state reflects how the PHB's internal concept of a PE is
configured. This is separate to the EEH PE state and is managed power
the PowerNV PCI backend rather than the EEH core.

Signed-off-by: Oliver O'Halloran <oohall@gmail.com>
Reviewed-by: Alexey Kardashevskiy <aik@ozlabs.ru>
[mpe: Use DEFINE_DEBUGFS_ATTRIBUTE]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20190912052945.12589-3-oohall@gmail.com
2020-01-23 21:31:20 +11:00
Oliver O'Halloran
c13a17b73e powernv/pci: Allow any write trigger the diag dump
Make the dump trigger off any input rather than just '1'. This allows you
to write "echo 1> dump_diag_data" and it'll do what you want rather than
erroring out pointlessly.

Signed-off-by: Oliver O'Halloran <oohall@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20190912052945.12589-2-oohall@gmail.com
2020-01-23 21:31:20 +11:00
Oliver O'Halloran
22ba728907 powernv/pci: Use pnv_phb as the private data for debugfs entries
Use the pnv_phb structure as the private data pointer for the debugfs
files.  This lets us delete some code and an open-coded use of
hose->private_data.

Signed-off-by: Oliver O'Halloran <oohall@gmail.com>
Reviewed-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20190912052945.12589-1-oohall@gmail.com
2020-01-23 21:31:20 +11:00
Oliver O'Halloran
a4af49f34f powerpc/pcidn: Warn when sriov pci_dn management is used incorrectly
These functions can only be used on a SR-IOV capable physical function and
they're only called in pcibios_sriov_enable / disable. Make them emit a
warning in the future if they're used incorrectly and remove the dead
code that checks if the device is a VF.

Signed-off-by: Oliver O'Halloran <oohall@gmail.com>
Reviewed-by: Sam Bobroff <sbobroff@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20190821062655.19735-3-oohall@gmail.com
2020-01-23 21:31:19 +11:00
Oliver O'Halloran
8cd6aacc64 powerpc/pcidn: Make VF pci_dn management CONFIG_PCI_IOV specific
The powerpc PCI code requires that a pci_dn structure exists for all
devices in the system. This is fine for real devices since at boot a pci_dn
is created for each PCI device in the DT and it's fine for hotplugged devices
since the hotplug slot driver will manage the pci_dn's devices in hotplug
slots. For SR-IOV, we need the platform / pcibios to manage the pci_dn for
virtual functions since firmware is unaware of VFs, and they aren't
"hot plugged" in the traditional sense.

Management of the pci_dn is handled by the, poorly named, functions:
add_pci_dev_data() and remove_pci_dev_data(). The entire body of these
functions is #ifdef`ed around CONFIG_PCI_IOV and they cannot be used
in any other context, so make them only available when CONFIG_PCI_IOV
is selected, and rename them to reflect their actual usage rather than
having them masquerade as generic code.

Signed-off-by: Oliver O'Halloran <oohall@gmail.com>
Reviewed-by: Sam Bobroff <sbobroff@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20190821062655.19735-2-oohall@gmail.com
2020-01-23 21:31:19 +11:00
Oliver O'Halloran
1fb4124ca9 powerpc/sriov: Remove VF eeh_dev state when disabling SR-IOV
When disabling virtual functions on an SR-IOV adapter we currently do not
correctly remove the EEH state for the now-dead virtual functions. When
removing the pci_dn that was created for the VF when SR-IOV was enabled
we free the corresponding eeh_dev without removing it from the child device
list of the eeh_pe that contained it. This can result in crashes due to the
use-after-free.

Signed-off-by: Oliver O'Halloran <oohall@gmail.com>
Reviewed-by: Sam Bobroff <sbobroff@linux.ibm.com>
Tested-by: Sam Bobroff <sbobroff@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20190821062655.19735-1-oohall@gmail.com
2020-01-23 21:31:19 +11:00
Oliver O'Halloran
3489cdc417 powerpc/eeh_sysfs: Make clearing EEH_DEV_SYSFS saner
The eeh_sysfs_remove_device() function is supposed to clear the
EEH_DEV_SYSFS flag since it indicates the EEH sysfs entries have been added
for a pci_dev.

When the sysfs files are removed eeh_remove_device() the eeh_dev and the
pci_dev have already been de-associated. This then causes the
pci_dev_to_eeh_dev() call in eeh_sysfs_remove_device() to return NULL so
the flag can't be cleared from the still-live eeh_dev. This problem is
worked around in the caller by clearing the flag manually. However, this
behaviour doesn't make a whole lot of sense, so this patch fixes it by:

a) Re-ordering eeh_remove_device() so that eeh_sysfs_remove_device() is
   called before de-associating the pci_dev and eeh_dev.

b) Making eeh_sysfs_remove_device() emit a warning if there's no
   corresponding eeh_dev for a pci_dev. The paths where the sysfs
   files are only reachable if EEH was setup for the device
   for the device in the first place so hitting this warning
   indicates a programming error.

Signed-off-by: Oliver O'Halloran <oohall@gmail.com>
Reviewed-by: Sam Bobroff <sbobroff@linux.ibm.com>
Tested-by: Sam Bobroff <sbobroff@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20190715085612.8802-6-oohall@gmail.com
2020-01-23 21:31:19 +11:00
Oliver O'Halloran
758b423275 powerpc/eeh_sysfs: Remove double pci_dn lookup.
In eeh_notify_resume_show() the pci_dn for the device is looked up once in
the declaration block and then once after checking for a NULL eeh_dev.
Remove the second lookup since it's pointless.

Signed-off-by: Oliver O'Halloran <oohall@gmail.com>
Reviewed-by: Sam Bobroff <sbobroff@linux.ibm.com>
Tested-by: Sam Bobroff <sbobroff@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20190715085612.8802-5-oohall@gmail.com
2020-01-23 21:31:19 +11:00
Oliver O'Halloran
4107248c56 powerpc/eeh_sysfs: ifdef pseries sr-iov sysfs properties
There are several EEH sysfs properties that only exists when the
"ibm,is-open-sriov-pf" property appears in the device tree node of the PCI
device. This used on pseries to indicate to the guest that the hypervisor
allows the guest to configure the SR-IOV capability. Doing this requires
some handshaking between the guest, hypervisor and userspace when a VF is
EEH frozen which is why these properties exist.

This is all dead code on non-pseries platforms so wrap it in an #ifdef
CONFIG_PPC_PSERIES to make the dependency clearer.

Signed-off-by: Oliver O'Halloran <oohall@gmail.com>
Tested-by: Sam Bobroff <sbobroff@linux.ibm.com>
Reviewed-by: Sam Bobroff <sbobroff@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20190715085612.8802-4-oohall@gmail.com
2020-01-23 21:31:18 +11:00
Oliver O'Halloran
89f51839bd powerpc/eeh_sysfs: Fix incorrect comment
The EEH_ATTR_SHOW() helper is used to display fields from struct eeh_dev
not struct pci_dn.

Signed-off-by: Oliver O'Halloran <oohall@gmail.com>
Reviewed-by: Sam Bobroff <sbobroff@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20190715085612.8802-3-oohall@gmail.com
2020-01-23 21:31:18 +11:00
Oliver O'Halloran
b1268f4cdb powerpc/eeh_cache: Don't use pci_dn when inserting new ranges
At the point where we start inserting ranges into the EEH address cache the
binding between pci_dev and eeh_dev has already been set up. Instead of
consulting the pci_dn tree we can retrieve the eeh_dev directly using
pci_dev_to_eeh_dev().

Signed-off-by: Oliver O'Halloran <oohall@gmail.com>
Reviewed-by: Sam Bobroff <sbobroff@linux.ibm.com>
Tested-by: Sam Bobroff <sbobroff@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20190715085612.8802-2-oohall@gmail.com
2020-01-23 21:31:18 +11:00
Frederic Barrat
bbb7890460 powerpc/powernv/ioda: Find opencapi slot for a device node
Unlike real PCI slots, opencapi slots are directly associated to
the (virtual) opencapi PHB, there's no intermediate bridge. So when
looking for a slot ID, we must start the search from the device node
itself and not its parent.

Also, the slot ID is not attached to a specific bdfn, so let's build
it from the PHB ID, like skiboot.

Signed-off-by: Frederic Barrat <fbarrat@linux.ibm.com>
Reviewed-by: Andrew Donnellan <ajd@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20191121134918.7155-6-fbarrat@linux.ibm.com
2020-01-23 21:31:17 +11:00
Frederic Barrat
f724385fea powerpc/powernv/ioda: Release opencapi device
With hotplug, an opencapi device can now go away. It needs to be
released, mostly to clean up its PE state. We were previously not
defining any device callback. We can reuse the standard PCI release
callback, it does a bit too much for an opencapi device, but it's
harmless, and only needs minor tuning.

Also separate the undo of the PELT-V code in a separate function, it
is not needed for NPU devices and it improves a bit the readability of
the code.

Signed-off-by: Frederic Barrat <fbarrat@linux.ibm.com>
Reviewed-by: Andrew Donnellan <ajd@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20191121134918.7155-5-fbarrat@linux.ibm.com
2020-01-23 21:31:16 +11:00
Frederic Barrat
c1a2feade0 powerpc/powernv/ioda: set up PE on opencapi device when enabling
The PE for an opencapi device was set as part of a late PHB fixup
operation, when creating the PHB. To use the PCI hotplug framework,
this is not going to work, as the PHB stays the same, it's only the
devices underneath which are updated. For regular PCI devices, it is
done as part of the reconfiguration of the bridge, but for opencapi
PHBs, we don't have an intermediate bridge. So let's define the PE
when the device is enabled. PEs are meaningless for opencapi, the NPU
doesn't define them and opal is not doing anything with them.

Reviewed-by: Alastair D'Silva <alastair@d-silva.org>
Reviewed-by: Andrew Donnellan <ajd@linux.ibm.com>
Signed-off-by: Frederic Barrat <fbarrat@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20191121134918.7155-4-fbarrat@linux.ibm.com
2020-01-23 21:31:16 +11:00
Frederic Barrat
80f1ff83fa powerpc/powernv/ioda: Protect PE list
Protect the PHB's list of PE. Probably not needed as long as it was
populated during PHB creation, but it feels right and will become
required once we can add/remove opencapi devices on hotplug.

Reviewed-by: Andrew Donnellan <ajd@linux.ibm.com>
Signed-off-by: Frederic Barrat <fbarrat@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20191121134918.7155-3-fbarrat@linux.ibm.com
2020-01-23 21:31:16 +11:00
Frederic Barrat
05dd7da769 powerpc/powernv/ioda: Fix ref count for devices with their own PE
The pci_dn structure used to store a pointer to the struct pci_dev, so
taking a reference on the device was required. However, the pci_dev
pointer was later removed from the pci_dn structure, but the reference
was kept for the npu device.
See commit 902bdc5745 ("powerpc/powernv/idoa: Remove unnecessary
pcidev from pci_dn").

We don't need to take a reference on the device when assigning the PE
as the struct pnv_ioda_pe is cleaned up at the same time as
the (physical) device is released. Doing so prevents the device from
being released, which is a problem for opencapi devices, since we want
to be able to remove them through PCI hotplug.

Now the ugly part: nvlink npu devices are not meant to be
released. Because of the above, we've always leaked a reference and
simply removing it now is dangerous and would likely require more
work. There's currently no release device callback for nvlink devices
for example. So to be safe, this patch leaks a reference on the npu
device, but only for nvlink and not opencapi.

Signed-off-by: Frederic Barrat <fbarrat@linux.ibm.com>
Reviewed-by: Andrew Donnellan <ajd@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20191121134918.7155-2-fbarrat@linux.ibm.com
2020-01-23 21:31:16 +11:00
Christophe Leroy
bfc2eae0ad powerpc/vdso32: miscellaneous optimisations
Various optimisations by inverting branches and removing
redundant instructions.

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/b4e79f963845545bcce1459cd6fcfe46bdde7863.1575273217.git.christophe.leroy@c-s.fr
2020-01-23 21:31:16 +11:00
Christophe Leroy
e33ffc956b powerpc/vdso32: implement clock_getres entirely
clock_getres returns hrtimer_res for all clocks but coarse ones
for which it returns KTIME_LOW_RES.

return EINVAL for unknown clocks.

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/37f94e47c91070b7606fb3ec3fe6fd2302a475a0.1575273217.git.christophe.leroy@c-s.fr
2020-01-23 21:31:15 +11:00
Christophe Leroy
6e2f9e9cfd powerpc/vdso32: use LOAD_REG_IMMEDIATE()
Use LOAD_REG_IMMEDIATE() to load registers with immediate value.

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/36f111437e66e601929308f5d5dce230e1ce472f.1575273217.git.christophe.leroy@c-s.fr
2020-01-23 21:31:15 +11:00
Christophe Leroy
2c29eef9fc powerpc/vdso32: Don't read cache line size from the datapage on PPC32.
On PPC32, the cache lines have a fixed size known at build time.

Don't read it from the datapage.

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/dfa7b35e27e01964fcda84bf1ed8b2b31cf93826.1575273217.git.christophe.leroy@c-s.fr
2020-01-23 21:31:15 +11:00
Christophe Leroy
ec0895f08f powerpc/vdso32: inline __get_datapage()
__get_datapage() is only a few instructions to retrieve the
address of the page where the kernel stores data to the VDSO.

By inlining this function into its users, a bl/blr pair and
a mflr/mtlr pair is avoided, plus a few reg moves.

The improvement is noticeable (about 55 nsec/call on an 8xx)

vdsotest before the patch:
gettimeofday:    vdso: 731 nsec/call
clock-gettime-realtime-coarse:    vdso: 668 nsec/call
clock-gettime-monotonic-coarse:    vdso: 745 nsec/call

vdsotest after the patch:
gettimeofday:    vdso: 677 nsec/call
clock-gettime-realtime-coarse:    vdso: 613 nsec/call
clock-gettime-monotonic-coarse:    vdso: 690 nsec/call

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/c39ef7f3dfa25356b01e211d539671f279086c09.1575273217.git.christophe.leroy@c-s.fr
2020-01-23 21:31:15 +11:00
Christophe Leroy
654abc69ef powerpc/vdso32: Add support for CLOCK_{REALTIME/MONOTONIC}_COARSE
This is copied and adapted from commit 5c929885f1 ("powerpc/vdso64:
Add support for CLOCK_{REALTIME/MONOTONIC}_COARSE")
from Santosh Sivaraj <santosh@fossix.org>

Benchmark from vdsotest-all:
clock-gettime-realtime: syscall: 3601 nsec/call
clock-gettime-realtime:    libc: 1072 nsec/call
clock-gettime-realtime:    vdso: 931 nsec/call
clock-gettime-monotonic: syscall: 4034 nsec/call
clock-gettime-monotonic:    libc: 1213 nsec/call
clock-gettime-monotonic:    vdso: 1076 nsec/call
clock-gettime-realtime-coarse: syscall: 2722 nsec/call
clock-gettime-realtime-coarse:    libc: 805 nsec/call
clock-gettime-realtime-coarse:    vdso: 668 nsec/call
clock-gettime-monotonic-coarse: syscall: 2949 nsec/call
clock-gettime-monotonic-coarse:    libc: 882 nsec/call
clock-gettime-monotonic-coarse:    vdso: 745 nsec/call

Additional test passed with:
	vdsotest -d 30 clock-gettime-monotonic-coarse verify

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://github.com/linuxppc/issues/issues/41
Link: https://lore.kernel.org/r/d1d24a376e396540194eeb85a2efe481e92ade24.1575273217.git.christophe.leroy@c-s.fr
2020-01-23 21:31:15 +11:00