[tree-wide] finally take no_llseek out

no_llseek had been defined to NULL two years ago, in commit 868941b14441
("fs: remove no_llseek")

To quote that commit,

At -rc1 we'll need do a mechanical

[tree-wide] finally take no_llseek out

no_llseek had been defined to NULL two years ago, in commit 868941b14441
("fs: remove no_llseek")

To quote that commit,

At -rc1 we'll need do a mechanical removal of no_llseek -

git grep -l -w no_llseek | grep -v porting.rst | while read i; do
sed -i '/\<no_llseek\>/d' $i
done

would do it.

Unfortunately, that hadn't been done. Linus, could you do that now, so
that we could finally put that thing to rest? All instances are of the
form
.llseek = no_llseek,
so it's obviously safe.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

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intel_th: msu: Fix kernel-doc warnings

Correct function comments to prevent kernel-doc warnings
found when using "W=1".

msu.c:77: warning: Function parameter or member 'msc' not described in 'msc_w

intel_th: msu: Fix kernel-doc warnings

Correct function comments to prevent kernel-doc warnings
found when using "W=1".

msu.c:77: warning: Function parameter or member 'msc' not described in 'msc_window'
msu.c:122: warning: bad line:
msu.c:760: warning: No description found for return value of 'msc_configure'
msu.c:1309: warning: Function parameter or member 'nr_pages' not described in 'msc_buffer_alloc'
msu.c:1309: warning: Function parameter or member 'nr_wins' not described in 'msc_buffer_alloc'
msu.c:1309: warning: Excess function parameter 'size' description in 'msc_buffer_alloc'
msu.c:1376: warning: No description found for return value of 'msc_buffer_free_unless_used'
msu.c:1444: warning: No description found for return value of 'msc_win_to_user'

Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20240429130119.1518073-10-alexander.shishkin@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

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mm: replace vma->vm_flags direct modifications with modifier calls

Replace direct modifications to vma->vm_flags with calls to modifier
functions to be able to track flag changes and to keep vma loc

mm: replace vma->vm_flags direct modifications with modifier calls

Replace direct modifications to vma->vm_flags with calls to modifier
functions to be able to track flag changes and to keep vma locking
correctness.

[akpm@linux-foundation.org: fix drivers/misc/open-dice.c, per Hyeonggon Yoo]
Link: https://lkml.kernel.org/r/20230126193752.297968-5-surenb@google.com
Signed-off-by: Suren Baghdasaryan <surenb@google.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Mel Gorman <mgorman@techsingularity.net>
Acked-by: Mike Rapoport (IBM) <rppt@kernel.org>
Acked-by: Sebastian Reichel <sebastian.reichel@collabora.com>
Reviewed-by: Liam R. Howlett <Liam.Howlett@Oracle.com>
Reviewed-by: Hyeonggon Yoo <42.hyeyoo@gmail.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Arjun Roy <arjunroy@google.com>
Cc: Axel Rasmussen <axelrasmussen@google.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: David Rientjes <rientjes@google.com>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Greg Thelen <gthelen@google.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jann Horn <jannh@google.com>
Cc: Joel Fernandes <joelaf@google.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Kent Overstreet <kent.overstreet@linux.dev>
Cc: Laurent Dufour <ldufour@linux.ibm.com>
Cc: Lorenzo Stoakes <lstoakes@gmail.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Minchan Kim <minchan@google.com>
Cc: Paul E. McKenney <paulmck@kernel.org>
Cc: Peter Oskolkov <posk@google.com>
Cc: Peter Xu <peterx@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Punit Agrawal <punit.agrawal@bytedance.com>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Soheil Hassas Yeganeh <soheil@google.com>
Cc: Song Liu <songliubraving@fb.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

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intel_th: msu: Fix vmalloced buffers

After commit f5ff79fddf0e ("dma-mapping: remove CONFIG_DMA_REMAP") there's
a chance of DMA buffer getting allocated via vmalloc(), which messes up
the mmapping c

intel_th: msu: Fix vmalloced buffers

After commit f5ff79fddf0e ("dma-mapping: remove CONFIG_DMA_REMAP") there's
a chance of DMA buffer getting allocated via vmalloc(), which messes up
the mmapping code:

> RIP: msc_mmap_fault [intel_th_msu]
> Call Trace:
> <TASK>
> __do_fault
> do_fault
...

Fix this by accounting for vmalloc possibility.

Fixes: ba39bd830605 ("intel_th: msu: Switch over to scatterlist")
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Link: https://lore.kernel.org/r/20220705082637.59979-4-alexander.shishkin@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

show more ...

intel_th: msu: Use memset_startat() for clearing hw header

In preparation for FORTIFY_SOURCE performing compile-time and run-time
field bounds checking for memset(), avoid intentionally writing acro

intel_th: msu: Use memset_startat() for clearing hw header

In preparation for FORTIFY_SOURCE performing compile-time and run-time
field bounds checking for memset(), avoid intentionally writing across
neighboring fields.

Use memset_startat() so memset() doesn't get confused about writing
beyond the destination member that is intended to be the starting point
of zeroing through the end of the struct.

Acked-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Link: https://lore.kernel.org/lkml/87sfyzi97l.fsf@ashishki-desk.ger.corp.intel.com
Signed-off-by: Kees Cook <keescook@chromium.org>

show more ...

intel_th: msu: Make contiguous buffers uncached

We already keep the multiblock mode buffers uncached, but forget the
single mode. Address this.

Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux

intel_th: msu: Make contiguous buffers uncached

We already keep the multiblock mode buffers uncached, but forget the
single mode. Address this.

Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Link: https://lore.kernel.org/r/20210621151246.31891-4-alexander.shishkin@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

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intel_th: Constify attribute_group structs

The only usage of them is to pass their address to sysfs_create_group()
and sysfs_remove_group(), both which have pointers to const
attribute_group structs

intel_th: Constify attribute_group structs

The only usage of them is to pass their address to sysfs_create_group()
and sysfs_remove_group(), both which have pointers to const
attribute_group structs as input. Make them const to allow the compiler
to put them in read-only memory.

Signed-off-by: Rikard Falkeborn <rikard.falkeborn@gmail.com>
Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20210414171251.14672-5-alexander.shishkin@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

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hwtracing: intel: use krealloc_array()

Use the helper that checks for overflows internally instead of manually
calculating the size of the new array.

Link: https://lkml.kernel.org/r/20201109110654.

hwtracing: intel: use krealloc_array()

Use the helper that checks for overflows internally instead of manually
calculating the size of the new array.

Link: https://lkml.kernel.org/r/20201109110654.12547-9-brgl@bgdev.pl
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Borislav Petkov <bp@suse.de>
Cc: Christian Knig <christian.koenig@amd.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: David Airlie <airlied@linux.ie>
Cc: David Rientjes <rientjes@google.com>
Cc: Gustavo Padovan <gustavo@padovan.org>
Cc: James Morse <james.morse@arm.com>
Cc: Jaroslav Kysela <perex@perex.cz>
Cc: Jason Wang <jasowang@redhat.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Linus Walleij <linus.walleij@linaro.org>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Mauro Carvalho Chehab <mchehab@kernel.org>
Cc: Maxime Ripard <mripard@kernel.org>
Cc: "Michael S . Tsirkin" <mst@redhat.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Robert Richter <rric@kernel.org>
Cc: Sumit Semwal <sumit.semwal@linaro.org>
Cc: Takashi Iwai <tiwai@suse.com>
Cc: Takashi Iwai <tiwai@suse.de>
Cc: Thomas Zimmermann <tzimmermann@suse.de>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

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intel_th: msu: Make stopping the trace optional

Some use cases prefer to keep collecting the trace data into the last
available window while the other windows are being offloaded instead of
stopping

intel_th: msu: Make stopping the trace optional

Some use cases prefer to keep collecting the trace data into the last
available window while the other windows are being offloaded instead of
stopping the trace. In this scenario, the window switch happens
automatically when the next window becomes available again.

Add an option to allow this and a sysfs attribute to enable it.

Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20200319085152.52183-1-alexander.shishkin@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

show more ...

intel_th: Fix user-visible error codes

There are a few places in the driver that end up returning ENOTSUPP to
the user, replace those with EINVAL.

Signed-off-by: Alexander Shishkin <alexander.shish

intel_th: Fix user-visible error codes

There are a few places in the driver that end up returning ENOTSUPP to
the user, replace those with EINVAL.

Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Fixes: ba82664c134ef ("intel_th: Add Memory Storage Unit driver")
Cc: stable@vger.kernel.org # v4.4+
Link: https://lore.kernel.org/r/20200317062215.15598-6-alexander.shishkin@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

show more ...

intel_th: msu: Fix the unexpected state warning

The unexpected state warning should only warn on illegal state
transitions. Fix that.

Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.int

intel_th: msu: Fix the unexpected state warning

The unexpected state warning should only warn on illegal state
transitions. Fix that.

Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Fixes: 615c164da0eb4 ("intel_th: msu: Introduce buffer interface")
Cc: stable@vger.kernel.org # v5.4+
Link: https://lore.kernel.org/r/20200317062215.15598-5-alexander.shishkin@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

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intel_th: Disallow multi mode on devices where it's broken

Some versions of Intel TH have an issue that prevents the multi mode of
MSU from working correctly, resulting in no trace data and potentia

intel_th: Disallow multi mode on devices where it's broken

Some versions of Intel TH have an issue that prevents the multi mode of
MSU from working correctly, resulting in no trace data and potentially
stuck MSU pipeline.

Disable multi mode on such devices.

Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20200317062215.15598-2-alexander.shishkin@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

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intel_th: msu: Fix window switching without windows

Commit 6cac7866c2741 ("intel_th: msu: Add a sysfs attribute to trigger
window switch") adds a NULL pointer dereference in the case when there are

intel_th: msu: Fix window switching without windows

Commit 6cac7866c2741 ("intel_th: msu: Add a sysfs attribute to trigger
window switch") adds a NULL pointer dereference in the case when there are
no windows allocated:

> BUG: kernel NULL pointer dereference, address: 0000000000000000
> #PF: supervisor read access in kernel mode
> #PF: error_code(0x0000) - not-present page
> PGD 0 P4D 0
> Oops: 0000 1 SMP
> CPU: 5 PID: 1110 Comm: bash Not tainted 5.5.0-rc1+ #1
> RIP: 0010:msc_win_switch+0xa/0x80 [intel_th_msu]
> Call Trace:
> ? win_switch_store+0x9b/0xc0 [intel_th_msu]
> dev_attr_store+0x17/0x30
> sysfs_kf_write+0x3e/0x50
> kernfs_fop_write+0xda/0x1b0
> __vfs_write+0x1b/0x40
> vfs_write+0xb9/0x1a0
> ksys_write+0x67/0xe0
> __x64_sys_write+0x1a/0x20
> do_syscall_64+0x57/0x1d0
> entry_SYSCALL_64_after_hwframe+0x44/0xa9

Fix that by disallowing window switching with multiwindow buffers without
windows.

Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Fixes: 6cac7866c274 ("intel_th: msu: Add a sysfs attribute to trigger window switch")
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reported-by: Ammy Yi <ammy.yi@intel.com>
Tested-by: Ammy Yi <ammy.yi@intel.com>
Cc: stable@vger.kernel.org # v5.2+
Link: https://lore.kernel.org/r/20191217115527.74383-5-alexander.shishkin@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

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intel_th: msu: Fix possible memory leak in mode_store()

'mode' is malloced in mode_store() and should be freed before leaving
from the error handling cases, otherwise it will cause memory leak.

Fix

intel_th: msu: Fix possible memory leak in mode_store()

'mode' is malloced in mode_store() and should be freed before leaving
from the error handling cases, otherwise it will cause memory leak.

Fixes: 615c164da0eb ("intel_th: msu: Introduce buffer interface")
Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com>
Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/lkml/20190801013825.182543-1-weiyongjun1@huawei.com/
Link: https://lore.kernel.org/r/20191028070651.9770-6-alexander.shishkin@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

show more ...

intel_th: msu: Fix overflow in shift of an unsigned int

The shift of the unsigned int win->nr_blocks by PAGE_SHIFT may
potentially overflow. Note that the intended return of this shift
is expected t

intel_th: msu: Fix overflow in shift of an unsigned int

The shift of the unsigned int win->nr_blocks by PAGE_SHIFT may
potentially overflow. Note that the intended return of this shift
is expected to be a size_t however the shift is being performed as
an unsigned int. Fix this by casting win->nr_blocks to a size_t
before performing the shift.

Addresses-Coverity: ("Unintentional integer overflow")
Fixes: 615c164da0eb ("intel_th: msu: Introduce buffer interface")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/lkml/20190726113151.8967-1-colin.king@canonical.com/
Link: https://lore.kernel.org/r/20191028070651.9770-5-alexander.shishkin@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

show more ...

intel_th: msu: Fix missing allocation failure check on a kstrndup

Commit 615c164da0eb ("intel_th: msu: Introduce buffer interface") forgot
to add a NULL pointer check for the value returned from kst

intel_th: msu: Fix missing allocation failure check on a kstrndup

Commit 615c164da0eb ("intel_th: msu: Introduce buffer interface") forgot
to add a NULL pointer check for the value returned from kstrdup(), which
will be troublesome if the allocation fails.

Fix that by adding the check.

Addresses-Coverity: ("Dereference null return")
Fixes: 615c164da0eb ("intel_th: msu: Introduce buffer interface")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
[alexander.shishkin: amended the commit message]
Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/lkml/20190726120421.9650-1-colin.king@canonical.com/
Link: https://lore.kernel.org/r/20191028070651.9770-4-alexander.shishkin@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

show more ...

intel_th: msu: Fix an uninitialized mutex

Commit 615c164da0eb ("intel_th: msu: Introduce buffer interface") added a
mutex that it forgot to initialize, resulting in a lockdep splat.

Fix that by ini

intel_th: msu: Fix an uninitialized mutex

Commit 615c164da0eb ("intel_th: msu: Introduce buffer interface") added a
mutex that it forgot to initialize, resulting in a lockdep splat.

Fix that by initializing the mutex statically.

Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Fixes: 615c164da0eb ("intel_th: msu: Introduce buffer interface")
Link: https://lore.kernel.org/r/20191028070651.9770-3-alexander.shishkin@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

show more ...

intel_th: msu: Preserve pre-existing buffer configuration

The MSU configuration registers may contain buffer address/size set by
the BIOS or an external hardware debugger, which may want to take ove

intel_th: msu: Preserve pre-existing buffer configuration

The MSU configuration registers may contain buffer address/size set by
the BIOS or an external hardware debugger, which may want to take over
tracing from the driver when the driver is not actively tracing.

Preserve these settings when not actively tracing.

Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20190705141425.19894-6-alexander.shishkin@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

show more ...

intel_th: msu: Prevent freeing buffers while locked windows exist

We already prevent freeing buffers via sysfs interface in case there are
existing users or if trace is active. Treat the existence o

intel_th: msu: Prevent freeing buffers while locked windows exist

We already prevent freeing buffers via sysfs interface in case there are
existing users or if trace is active. Treat the existence of locked windows
similarly and return -EBUSY on attempts to free the buffer. When the last
window is unlocked, the freeing will succeed.

Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20190705141425.19894-5-alexander.shishkin@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

show more ...

intel_th: msu: Get rid of the window size limit

Currently, the window size is limited to the maximum number of sg entries
in one table. This is because the code addresses individual blocks within
th

intel_th: msu: Get rid of the window size limit

Currently, the window size is limited to the maximum number of sg entries
in one table. This is because the code addresses individual blocks within
the window by their numeric index. In reality, though, the blocks most
often are iterated through sequentially. By rewriting the logic to use sg
pointers instead of block indices we loose the necessity to dereference
them directly and gain the ability to use multiple chained tables if
necessary.

Get rid of the limitation by replacing index-based block accesses with
sequential block accesses.

Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20190705141425.19894-4-alexander.shishkin@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

show more ...

intel_th: msu: Introduce buffer interface

Introduces a concept of external buffers, which is a mechanism for creating
trace sinks that would receive trace data from MSC buffers and transfer it
elsew

intel_th: msu: Introduce buffer interface

Introduces a concept of external buffers, which is a mechanism for creating
trace sinks that would receive trace data from MSC buffers and transfer it
elsewhere.

A external buffer can implement its own window allocation/deallocation if
it has to. It must provide a callback that's used to notify it when a
window fills up, so that it can then start a DMA transaction from that
window 'elsewhere'. This window remains in a 'locked' state and won't be
used for storing new trace data until the buffer 'unlocks' it with a
provided API call, at which point the window can be used again for storing
trace data.

This relies on a functional "last block" interrupt, so not all versions of
Trace Hub can use this feature, which does not reflect on existing users.

Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20190705141425.19894-2-alexander.shishkin@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

show more ...

intel_th: msu: Start read iterator from a non-empty window

In multi-window mode, the read iterator is supposed to start from the
window with the oldest data, which is, chronologically, the next wind

intel_th: msu: Start read iterator from a non-empty window

In multi-window mode, the read iterator is supposed to start from the
window with the oldest data, which is, chronologically, the next window
after the one with the newest data. This, however, fails to take into
account the potentially empty windows, so in short trace sessions it's
possible to have a lot of zeroes read from the character device first.

Fix this by skipping over the empty windows in initialization of the
read iterator.

Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20190627125152.54905-5-alexander.shishkin@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

show more ...

intel_th: msu: Split sgt array and pointer in multiwindow mode

To allow the use of externally allocated SG tables further down the line,
change the code to reference the table via a pointer and make

intel_th: msu: Split sgt array and pointer in multiwindow mode

To allow the use of externally allocated SG tables further down the line,
change the code to reference the table via a pointer and make it point to
the locally allocated table by default.

Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20190627125152.54905-4-alexander.shishkin@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

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intel_th: msu: Support multipage blocks

Now that the MSU is using scatterlist, we can support multipage blocks.
At the moment, the code assumes that all blocks are page-sized, but in
larger buffers

intel_th: msu: Support multipage blocks

Now that the MSU is using scatterlist, we can support multipage blocks.
At the moment, the code assumes that all blocks are page-sized, but in
larger buffers it may make sense to chunk together larger blocks of
memory. One place where one-to-many relationship needs to be handled is
the MSU buffer's mmap path.

Get rid of the implicit assumption that all blocks are page-sized.

Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20190627125152.54905-3-alexander.shishkin@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

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intel_th: msu: Fix single mode with disabled IOMMU

Commit 4e0eaf239fb3 ("intel_th: msu: Fix single mode with IOMMU") switched
the single mode code to use dma mapping pages obtained from the page
all

intel_th: msu: Fix single mode with disabled IOMMU

Commit 4e0eaf239fb3 ("intel_th: msu: Fix single mode with IOMMU") switched
the single mode code to use dma mapping pages obtained from the page
allocator, but with IOMMU disabled, that may lead to using SWIOTLB bounce
buffers and without additional sync'ing, produces empty trace buffers.

Fix this by using a DMA32 GFP flag to the page allocation in single mode,
as the device supports full 32-bit DMA addressing.

Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Fixes: 4e0eaf239fb3 ("intel_th: msu: Fix single mode with IOMMU")
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reported-by: Ammy Yi <ammy.yi@intel.com>
Cc: stable <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/20190621161930.60785-4-alexander.shishkin@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

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