linux-toradex.git/arch/powerpc/kernel/eeh_driver.c, branch v4.14

powerpc/eeh: Remove unnecessary pointer to phb from eeh_dev

2017-08-31T04:26:09+00:00

The eeh_dev struct already holds a pointer to pci_dn which it does not
exist without and pci_dn itself holds the very same pointer so just
use it.

Signed-off-by: Alexey Kardashevskiy 
Signed-off-by: Michael Ellerman

powerpc/eeh: Clean up and document event handling functions

2017-05-02T12:41:43+00:00

Remove unnecessary tags in eeh_handle_normal_event(), and add function
comments for eeh_handle_normal_event() and eeh_handle_special_event().

The only functional difference is that in the case of a PE reaching the
maximum number of failures, rather than one message telling you of this
and suggesting you reseat the device, there are two separate messages.

Suggested-by: Alexey Kardashevskiy 
Signed-off-by: Russell Currey 
Reviewed-by: Andrew Donnellan 
Reviewed-by: Gavin Shan 
Signed-off-by: Michael Ellerman

powerpc/eeh: Avoid use after free in eeh_handle_special_event()

2017-05-02T12:41:43+00:00

eeh_handle_special_event() is called when an EEH event is detected but
can't be narrowed down to a specific PE.  This function looks through
every PE to find one in an erroneous state, then calls the regular event
handler eeh_handle_normal_event() once it knows which PE has an error.

However, if eeh_handle_normal_event() found that the PE cannot possibly
be recovered, it will free it, rendering the passed PE stale.
This leads to a use after free in eeh_handle_special_event() as it attempts to
clear the "recovering" state on the PE after eeh_handle_normal_event() returns.

Thus, make sure the PE is valid when attempting to clear state in
eeh_handle_special_event().

Fixes: 8a6b1bc70dbb ("powerpc/eeh: EEH core to handle special event")
Cc: stable@vger.kernel.org # v3.11+
Reported-by: Alexey Kardashevskiy 
Signed-off-by: Russell Currey 
Reviewed-by: Gavin Shan 
Signed-off-by: Michael Ellerman

powerpc/eeh: Fix wrong flag passed to eeh_unfreeze_pe()

2017-01-24T10:22:51+00:00

In __eeh_clear_pe_frozen_state(), we should pass the flag's value
instead of its address to eeh_unfreeze_pe(). The isolated flag is
cleared if no error returned from __eeh_clear_pe_frozen_state(). We
never observed the error from the function. So the isolated flag should
have been always cleared, no real issue is caused because of the misused
@flag.

This fixes the code by passing the value of @flag to eeh_unfreeze_pe().

Fixes: 5cfb20b96f6 ("powerpc/eeh: Emulate EEH recovery for VFIO devices")
Cc: stable@vger.kernel.org # v3.18+
Signed-off-by: Gavin Shan 
Signed-off-by: Michael Ellerman

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

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
  ...

powerpc/eeh: Fix deadlock when PE frozen state can't be cleared

2016-12-01T11:26:27+00:00

In eeh_reset_device(), we take the pci_rescan_remove_lock immediately after
after we call eeh_reset_pe() to reset the PCI controller. We then call
eeh_clear_pe_frozen_state(), which can return an error. In this case, we
bail out of eeh_reset_device() without calling pci_unlock_rescan_remove().

Add a call to pci_unlock_rescan_remove() in the eeh_clear_pe_frozen_state()
error path so that we don't cause a deadlock later on.

Reported-by: Pradipta Ghosh 
Fixes: 78954700631f ("powerpc/eeh: Avoid I/O access during PE reset")
Cc: stable@vger.kernel.org # v3.16+
Signed-off-by: Andrew Donnellan 
Acked-by: Russell Currey 
Signed-off-by: Michael Ellerman

powerpc/eeh: Refactor EEH PE reset functions

2016-11-22T00:57:08+00:00

eeh_pe_reset and eeh_reset_pe are two different functions in the same
file which do mostly the same thing.  Not only is this confusing, but
potentially causes disrepancies in functionality, notably eeh_reset_pe
as it does not check return values for failure.

Refactor this into the following:

 - eeh_pe_reset(): stays as is, performs a single operation, exported
 - eeh_pe_reset_full(): new, full reset process that calls eeh_pe_reset()
 - eeh_reset_pe(): removed and replaced by eeh_pe_reset_full()
 - eeh_reset_pe_once(): removed

Signed-off-by: Russell Currey 
Signed-off-by: Michael Ellerman

powerpc/pci: Always print PHB and PE numbers as hexadecimal

2016-11-22T00:57:07+00:00

PHB, PE (and by association MVE) numbers are printed as a mix of decimal
and hexadecimal throughout the kernel.  This can be misleading, so make
them all hexadecimal.

Standardising on hex instead of dec because:

 - PHB numbers are presented in hex in sysfs/debugfs (and lspci, etc)
 - PE numbers are presented as hex in sysfs and parsed in hex in debugfs

The only place I think this could cause confusing are the messages during
boot, i.e.

	pci 000a:01     : [PE# 000] Secondary bus 1 associated with PE#0

which can be a quick way to check PE numbers.  pe_level_printk() will
only print two characters instead of three, so the above would be

	pci 000a:01     : [PE# 00] Secondary bus 1 associated with PE#0

which gives a hint it's in hex.

Signed-off-by: Russell Currey 
Signed-off-by: Michael Ellerman

powerpc/eeh: Skip finding bus until after failure reporting

2016-09-22T21:54:21+00:00

In eeh_handle_special_event(), eeh_pe_bus_get() is called before calling
eeh_report_failure() on every device under a PE.  If a PE was missing a
bus for some reason, the error would occur before reporting failure, even
though eeh_report_failure() doesn't require a bus.

Fix this by moving the bus retrieval and error check after the
eeh_report_failure() calls.

Signed-off-by: Russell Currey 
Reviewed-by: Andrew Donnellan 
Signed-off-by: Michael Ellerman

powerpc/eeh: Null check uses of eeh_pe_bus_get

2016-09-22T21:54:20+00:00

eeh_pe_bus_get() can return NULL if a PCI bus isn't found for a given PE.
Some callers don't check this, and can cause a null pointer dereference
under certain circumstances.

Fix this by checking NULL everywhere eeh_pe_bus_get() is called.

Fixes: 8a6b1bc70dbb ("powerpc/eeh: EEH core to handle special event")
Cc: stable@vger.kernel.org # v3.11+
Signed-off-by: Russell Currey 
Reviewed-by: Andrew Donnellan 
Signed-off-by: Michael Ellerman