linux-stable.git/drivers/misc, branch v3.18.9

mei: me: release hw from reset only during the reset flow

2015-03-06T22:53:00+00:00

commit 663b7ee9517eec6deea9a48c7a1392a9a34f7809 upstream.

We might enter the interrupt handler with hw_ready already set,
but prior we actually started the reset flow.
To soleve this we move the reset release from the interrupt handler
to the HW start wait function which is part of the reset sequence.

Signed-off-by: Alexander Usyskin 
Signed-off-by: Tomas Winkler 
Signed-off-by: Greg Kroah-Hartman

mei: mask interrupt set bit on clean reset bit

2015-03-06T22:52:59+00:00

commit 1ab1e79b9fd4b01331490bbe2e630a0fc0b25449 upstream.

We should mask interrupt set bit when writing back
hcsr value in reset bit clean-up.

This is refinement for
mei: clean reset bit before reset
commit b13a65ef190e488e2761d65bdd2e1fe8a3a125f5

Signed-off-by: Alexander Usyskin 
Signed-off-by: Tomas Winkler 
Signed-off-by: Greg Kroah-Hartman

mei: clean reset bit before reset

2015-01-27T16:29:41+00:00

commit b13a65ef190e488e2761d65bdd2e1fe8a3a125f5 upstream.

H_RST bit in H_CSR register may be found lit before reset is started,
for example if preceding reset flow hasn't completed.
In that case asserting H_RST will be ignored, therefore we need to clean
H_RST bit to start a successful reset sequence.

Signed-off-by: Alexander Usyskin 
Signed-off-by: Tomas Winkler 
Signed-off-by: Greg Kroah-Hartman 
Signed-off-by: Greg Kroah-Hartman

cxl: Unmap MMIO regions when detaching a context

2015-01-27T16:29:36+00:00

commit b123429e6a9e8d03aacf888d23262835f0081448 upstream.

If we need to force detach a context (e.g. due to EEH or simply force
unbinding the driver) we should prevent the userspace contexts from
being able to access the Problem State Area MMIO region further, which
they may have mapped with mmap().

This patch unmaps any mapped MMIO regions when detaching a userspace
context.

Signed-off-by: Ian Munsie 
Signed-off-by: Michael Ellerman 
Signed-off-by: Greg Kroah-Hartman

cxl: Add timeout to process element commands

2015-01-27T16:29:36+00:00

commit a98e6e9f4e0224d85b4d951edc44af16dfe6094a upstream.

In the event that something goes wrong in the hardware and it is unable
to complete a process element comment we would end up polling forever,
effectively making the associated process unkillable.

This patch adds a timeout to the process element command code path, so
that we will give up if the hardware does not respond in a reasonable
time.

Signed-off-by: Ian Munsie 
Signed-off-by: Michael Ellerman 
Signed-off-by: Greg Kroah-Hartman

cxl: Change contexts_lock to a mutex to fix sleep while atomic bug

2015-01-27T16:29:36+00:00

commit ee41d11d53c8fc4968f0816504651541d606cf40 upstream.

We had a known sleep while atomic bug if a CXL device was forcefully
unbound while it was in use. This could occur as a result of EEH, or
manually induced with something like this while the device was in use:

echo 0000:01:00.0 > /sys/bus/pci/drivers/cxl-pci/unbind

The issue was that in this code path we iterated over each context and
forcefully detached it with the contexts_lock spin lock held, however
the detach also needed to take the spu_mutex, and call schedule.

This patch changes the contexts_lock to a mutex so that we are not in
atomic context while doing the detach, thereby avoiding the sleep while
atomic.

Also delete the related TODO comment, which suggested an alternate
solution which turned out to not be workable.

Signed-off-by: Ian Munsie 
Signed-off-by: Michael Ellerman 
Signed-off-by: Greg Kroah-Hartman

misc: genwqe: check for error from get_user_pages_fast()

2015-01-16T14:59:50+00:00

commit cf35d6e0475982667b0d2d318fb27be4b8849827 upstream.

`genwqe_user_vmap()` calls `get_user_pages_fast()` and if the return
value is less than the number of pages requested, it frees the pages and
returns an error (`-EFAULT`).  However, it fails to consider a negative
error return value from `get_user_pages_fast()`.  In that case, the test
`if (rc < m->nr_pages)` will be false (due to promotion of `rc` to a
large `unsigned int`) and the code will continue on to call
`genwqe_map_pages()` with an invalid list of page pointers.  Fix it by
bailing out if `get_user_pages_fast()` returns a negative error value.

Signed-off-by: Ian Abbott 
Signed-off-by: Greg Kroah-Hartman

cxl: Fix PSL error due to duplicate segment table entries

2014-10-28T08:52:52+00:00

In certain circumstances the PSL (Power Service Layer, which provides
translation services for CXL hardware) can send an interrupt for a
segment miss that the kernel has already handled. This can happen if
multiple translations for the same segment are queued in the PSL before
the kernel has restarted the first translation.

The CXL driver does not expect this situation and does not check if a
segment had already been handled. This could cause a duplicate segment
table entry which in turn caused a PSL error taking down the card.

This patch fixes the issue by checking for existing entries in the
segment table that match the segment we are trying to insert, so as to
avoid inserting duplicate entries.

Signed-off-by: Ian Munsie 
Reviewed-by: Aneesh Kumar K.V 
Signed-off-by: Michael Ellerman

cxl: Refactor cxl_load_segment() and find_free_sste()

2014-10-28T08:52:24+00:00

This moves the segment table hash calculation from cxl_load_segment()
into find_free_sste() since that is the only place it is actually used.

Signed-off-by: Ian Munsie 
Reviewed-by: Aneesh Kumar K.V 
Signed-off-by: Michael Ellerman

cxl: Disable secondary hash in segment table

2014-10-28T08:52:07+00:00

This patch simplifies the process of finding a free segment table entry
by disabling the secondary hash. This reduces the number of possible
entries in the segment table for a given address from 16 to 8.

Due to the large segment sizes we use it is extremely unlikely that the
secondary hash would ever have been used in practice, so this should not
have any negative impacts and may even improve performance due to the
reduced number of comparisons that software & hardware need to perform.

This patch clears the SC bit in the hardware's state register
(CXL_PSL_SR_An) to disable the secondary hash in the hardware since we
can no longer fill out entries using it.

Signed-off-by: Ian Munsie 
Reviewed-by: Aneesh Kumar K.V 
Signed-off-by: Michael Ellerman