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  1. 14 Aug, 2015 12 commits
    • Daniel Axtens's avatar
      cxl: EEH support · 9e8df8a2
      Daniel Axtens authored 
      EEH (Enhanced Error Handling) allows a driver to recover from the
temporary failure of an attached PCI card. Enable basic CXL support
for EEH.
Signed-off-by: default avatarDaniel Axtens <dja@axtens.net>
Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
      9e8df8a2
    • Daniel Axtens's avatar
      cxl: Allow the kernel to trust that an image won't change on PERST. · 13e68d8b
      Daniel Axtens authored 
      Provide a kernel API and a sysfs entry which allow a user to specify
that when a card is PERSTed, it's image will stay the same, allowing
it to participate in EEH.

cxl_reset is used to reflash the card. In that case, we cannot safely
assert that the image will not change. Therefore, disallow cxl_reset
if the flag is set.
Signed-off-by: default avatarDaniel Axtens <dja@axtens.net>
Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
      13e68d8b
    • Daniel Axtens's avatar
      cxl: Don't remove AFUs/vPHBs in cxl_reset · 4e1efb40
      Daniel Axtens authored 
      If the driver doesn't participate in EEH, the AFUs will be removed
by cxl_remove, which will be invoked by EEH.

If the driver does particpate in EEH, the vPHB needs to stick around
so that the it can particpate.

In both cases, we shouldn't remove the AFU/vPHB.
Reviewed-by: default avatarCyril Bur <cyrilbur@gmail.com>
Signed-off-by: default avatarDaniel Axtens <dja@axtens.net>
Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
      4e1efb40
    • Daniel Axtens's avatar
      cxl: Refactor AFU init/teardown · d76427b0
      Daniel Axtens authored 
      As with an adapter, some aspects of initialisation are done only once
in the lifetime of an AFU: for example, allocating memory, or setting
up sysfs/debugfs files.

However, we may want to be able to do some parts of the initialisation
multiple times: for example, in error recovery we want to be able to
tear down and then re-map IO memory and IRQs.

Therefore, refactor AFU init/teardown as follows.

 - Create two new functions: 'cxl_configure_afu', and its pair
   'cxl_deconfigure_afu'. As with the adapter functions,
   these (de)configure resources that do not need to last the entire
   lifetime of the AFU.

 - Allocating and releasing memory remain the task of 'cxl_alloc_afu'
   and 'cxl_release_afu'.

 - Once-only functions that do not involve allocating/releasing memory
   stay in the overarching 'cxl_init_afu'/'cxl_remove_afu' pair.
   However, the task of picking an AFU mode and activating it has been
   broken out.
Signed-off-by: default avatarDaniel Axtens <dja@axtens.net>
Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
      d76427b0
    • Daniel Axtens's avatar
      cxl: Refactor adaptor init/teardown · c044c415
      Daniel Axtens authored 
      Some aspects of initialisation are done only once in the lifetime of
an adapter: for example, allocating memory for the adapter,
allocating the adapter number, or setting up sysfs/debugfs files.

However, we may want to be able to do some parts of the
initialisation multiple times: for example, in error recovery we
want to be able to tear down and then re-map IO memory and IRQs.

Therefore, refactor CXL init/teardown as follows.

 - Keep the overarching functions 'cxl_init_adapter' and its pair,
   'cxl_remove_adapter'.

 - Move all 'once only' allocation/freeing steps to the existing
   'cxl_alloc_adapter' function, and its pair 'cxl_release_adapter'
   (This involves moving allocation of the adapter number out of
   cxl_init_adapter.)

 - Create two new functions: 'cxl_configure_adapter', and its pair
   'cxl_deconfigure_adapter'. These two functions 'wire up' the
   hardware --- they (de)configure resources that do not need to
   last the entire lifetime of the adapter
Signed-off-by: default avatarDaniel Axtens <dja@axtens.net>
Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
      c044c415
    • Daniel Axtens's avatar
      cxl: Clean up adapter MMIO unmap path. · 575e6986
      Daniel Axtens authored 
      - MMIO pointer unmapping is guarded by a null pointer check.
   However, iounmap doesn't null the pointer, just invalidate it.
   Therefore, explicitly null the pointer after unmapping.

 - afu_desc_mmio also needs to be unmapped.

 - PCI regions are allocated in cxl_map_adapter_regs.
   Therefore they should be released in unmap, not elsewhere.
Acked-by: default avatarCyril Bur <cyrilbur@gmail.com>
Signed-off-by: default avatarDaniel Axtens <dja@axtens.net>
Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
      575e6986
    • Daniel Axtens's avatar
      cxl: Make IRQ release idempotent · e640d2fc
      Daniel Axtens authored 
      Check if an IRQ is mapped before releasing it.

This will simplify future EEH code by allowing unconditional unmapping
of IRQs.
Acked-by: default avatarCyril Bur <cyrilbur@gmail.com>
Signed-off-by: default avatarDaniel Axtens <dja@axtens.net>
Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
      e640d2fc
    • Daniel Axtens's avatar
      cxl: Allocate and release the SPA with the AFU · 05155772
      Daniel Axtens authored 
      Previously the SPA was allocated and freed upon entering and leaving
AFU-directed mode. This causes some issues for error recovery - contexts
hold a pointer inside the SPA, and they may persist after the AFU has
been detached.

We would ideally like to allocate the SPA when the AFU is allocated, and
release it until the AFU is released. However, we don't know how big the
SPA needs to be until we read the AFU descriptor.

Therefore, restructure the code:

 - Allocate the SPA only once, on the first attach.

 - Release the SPA only when the entire AFU is being released (not
   detached). Guard the release with a NULL check, so we don't free
   if it was never allocated (e.g. dedicated mode)
Acked-by: default avatarCyril Bur <cyrilbur@gmail.com>
Signed-off-by: default avatarDaniel Axtens <dja@axtens.net>
Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
      05155772
    • Daniel Axtens's avatar
      cxl: Drop commands if the PCI channel is not in normal state · 0b3f9c75
      Daniel Axtens authored 
      If the PCI channel has gone down, don't attempt to poke the hardware.

We need to guard every time cxl_whatever_(read|write) is called. This
is because a call to those functions will dereference an offset into an
mmio register, and the mmio mappings get invalidated in the EEH
teardown.

Check in the read/write functions in the header.
We give them the same semantics as usual PCI operations:
 - a write to a channel that is down is ignored.
 - a read from a channel that is down returns all fs.

Also, we try to access the MMIO space of a vPHB device as part of the
PCI disable path. Because that's a read that bypasses most of our usual
checks, we handle it explicitly.

As far as user visible warnings go:
 - Check link state in file ops, return -EIO if down.
 - Be reasonably quiet if there's an error in a teardown path,
   or when we already know the hardware is going down.
 - Throw a big WARN if someone tries to start a CXL operation
   while the card is down. This gives a useful stacktrace for
   debugging whatever is doing that.
Signed-off-by: default avatarDaniel Axtens <dja@axtens.net>
Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
      0b3f9c75
    • Daniel Axtens's avatar
      cxl: Convert MMIO read/write macros to inline functions · 588b34be
      Daniel Axtens authored 
      We're about to make these more complex, so make them functions
first.
Signed-off-by: default avatarDaniel Axtens <dja@axtens.net>
Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
      588b34be
    • Daniel Axtens's avatar
      powerpc/eeh: Probe after unbalanced kref check · e642d11b
      Daniel Axtens authored 
      In the complete hotplug case, EEH PEs are supposed to be released
and set to NULL. Normally, this is done by eeh_remove_device(),
which is called from pcibios_release_device().

However, if something is holding a kref to the device, it will not
be released, and the PE will remain. eeh_add_device_late() has
a check for this which will explictly destroy the PE in this case.

This check in eeh_add_device_late() occurs after a call to
eeh_ops->probe(). On PowerNV, probe is a pointer to pnv_eeh_probe(),
which will exit without probing if there is an existing PE.

This means that on PowerNV, devices with outstanding krefs will not
be rediscovered by EEH correctly after a complete hotplug. This is
affecting CXL (CAPI) devices in the field.

Put the probe after the kref check so that the PE is destroyed
and affected devices are correctly rediscovered by EEH.

Fixes: d91dafc0 ("powerpc/eeh: Delay probing EEH device during hotplug")
Cc: stable@vger.kernel.org
Cc: Gavin Shan <gwshan@linux.vnet.ibm.com>
Signed-off-by: default avatarDaniel Axtens <dja@axtens.net>
Acked-by: default avatarGavin Shan <gwshan@linux.vnet.ibm.com>
Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
      e642d11b
    • Gautham R. Shenoy's avatar
      powerpc: Add an inline function to update POWER8 HID0 · e63dbd16
      Gautham R. Shenoy authored 
      Section 3.7 of Version 1.2 of the Power8 Processor User's Manual
prescribes that updates to HID0 be preceded by a SYNC instruction and
followed by an ISYNC instruction (Page 91).

Create an inline function name update_power8_hid0() which follows this
recipe and invoke it from the static split core path.
Signed-off-by: default avatarGautham R. Shenoy <ego@linux.vnet.ibm.com>
Reviewed-by: default avatarSam Bobroff <sam.bobroff@au1.ibm.com>
Tested-by: default avatarSam Bobroff <sam.bobroff@au1.ibm.com>
Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
      e63dbd16
  3. 12 Aug, 2015 8 commits
  5. 10 Aug, 2015 1 commit
  7. 06 Aug, 2015 12 commits
  9. 30 Jul, 2015 3 commits
    • Michael Ellerman's avatar
      selftests/seccomp: Add powerpc support · 5d83c2b3
      Michael Ellerman authored 
      Wire up the syscall number and regs so the tests work on powerpc.

With the powerpc kernel support just merged, all tests pass on ppc64,
ppc64 (compat), ppc64le, ppc, ppc64e and ppc64e (compat).
Acked-by: default avatarKees Cook <keescook@chromium.org>
Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
      5d83c2b3
    • Michael Ellerman's avatar
      selftests/seccomp: Make seccomp tests work on big endian · c385d0db
      Michael Ellerman authored 
      The seccomp_bpf test uses BPF_LD|BPF_W|BPF_ABS to load 32-bit values
from seccomp_data->args. On big endian machines this will load the high
word of the argument, which is not what the test wants.

Borrow a hack from samples/seccomp/bpf-helper.h which changes the offset
on big endian to account for this.
Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
Acked-by: default avatarKees Cook <keescook@chromium.org>
      c385d0db
    • Michael Ellerman's avatar
      powerpc/kernel: Enable seccomp filter · 2449acc5
      Michael Ellerman authored 
      This commit enables seccomp filter on powerpc, now that we have all the
necessary pieces in place.

To support seccomp's desire to modify the syscall return value under
some circumstances, we use a different ABI to the ptrace ABI. That is we
use r3 as the syscall return value, and orig_gpr3 is the first syscall
parameter.

This means the seccomp code, or a ptracer via SECCOMP_RET_TRACE, will
see -ENOSYS preloaded in r3. This is identical to the behaviour on x86,
and allows seccomp or the ptracer to either leave the -ENOSYS or change
it to something else, as well as rejecting or not the syscall by
modifying r0.

If seccomp does not reject the syscall, we restore the register state to
match what ptrace and audit expect, ie. r3 is the first syscall
parameter again. We do this restore using orig_gpr3, which may have been
modified by seccomp, which allows seccomp to modify the first syscall
paramater and allow the syscall to proceed.

We need to #ifdef the the additional handling of r3 for seccomp, so move
it all out of line.
Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
Reviewed-by: default avatarKees Cook <keescook@chromium.org>
      2449acc5
  11. 29 Jul, 2015 4 commits
    • Michael Ellerman's avatar
      powerpc/kernel: Add SIG_SYS support for compat tasks · 1b60bab0
      Michael Ellerman authored 
      SIG_SYS was added in commit a0727e8c "signal, x86: add SIGSYS info
and make it synchronous."

Because we use the asm-generic struct siginfo, we got support for
SIG_SYS for free as part of that commit.

However there was no compat handling added for powerpc. That means we've
been advertising the existence of signfo._sifields._sigsys to compat
tasks, but not actually filling in the fields correctly.

Luckily it looks like no one has noticed, presumably because the only
user of SIGSYS in the kernel is seccomp filter, which we don't support
yet.

So before we enable seccomp filter, add compat handling for SIGSYS.
Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
Reviewed-by: default avatarKees Cook <keescook@chromium.org>
      1b60bab0
    • Michael Ellerman's avatar
      powerpc: Change syscall_get_nr() to return int · e9fbe686
      Michael Ellerman authored 
      The documentation for syscall_get_nr() in asm-generic says:

 Note this returns int even on 64-bit machines. Only 32 bits of
 system call number can be meaningful. If the actual arch value
 is 64 bits, this truncates to 32 bits so 0xffffffff means -1.

However our implementation was never updated to reflect this.

Generally it's not important, but there is once case where it matters.

For seccomp filter with SECCOMP_RET_TRACE, the tracer will set
regs->gpr[0] to -1 to reject the syscall. When the task is a compat
task, this means we end up with 0xffffffff in r0 because ptrace will
zero extend the 32-bit value.

If syscall_get_nr() returns an unsigned long, then a 64-bit kernel will
see a positive value in r0 and will incorrectly allow the syscall
through seccomp.
Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
Reviewed-by: default avatarKees Cook <keescook@chromium.org>
      e9fbe686
    • Michael Ellerman's avatar
      powerpc: Use orig_gpr3 in syscall_get_arguments() · 1cb9839b
      Michael Ellerman authored 
      Currently syscall_get_arguments() is used by syscall tracepoints, and
collect_syscall() which is used in some debugging as well as
/proc/pid/syscall.

The current implementation just copies regs->gpr[3 .. 5] out, which is
fine for all the current use cases.

When we enable seccomp filter, that will also start using
syscall_get_arguments(). However for seccomp filter we want to use r3
as the return value of the syscall, and orig_gpr3 as the first
parameter. This will allow seccomp to modify the return value in r3.

To support this we need to modify syscall_get_arguments() to return
orig_gpr3 instead of r3. This is safe for all uses because orig_gpr3
always contains the r3 value that was passed to the syscall. We store it
in the syscall entry path and never modify it.

Update syscall_set_arguments() while we're here, even though it's never
used.
Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
Reviewed-by: default avatarKees Cook <keescook@chromium.org>
      1cb9839b
    • Michael Ellerman's avatar
      powerpc: Rework syscall_get_arguments() so there is only one loop · a7657844
      Michael Ellerman authored 
      Currently syscall_get_arguments() has two loops, one for compat and one
for regular tasks. In prepartion for the next patch, which changes which
registers we use, switch it to only have one loop, so we only have one
place to update.
Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
Reviewed-by: default avatarKees Cook <keescook@chromium.org>
      a7657844
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