powerpc/vas: Add a couple of trace points

Add a couple of trace points in the VAS driver

Signed-off-by: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
[mpe: Add SPDX tag to new header]
Signed-off

powerpc/vas: Add a couple of trace points

Add a couple of trace points in the VAS driver

Signed-off-by: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
[mpe: Add SPDX tag to new header]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

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powerpc/vas: Don't set uses_vas for kernel windows

cp_abort is only required for user windows, because kernel context
must not be preempted between a copy/paste pair.

Without this patch, the init t

powerpc/vas: Don't set uses_vas for kernel windows

cp_abort is only required for user windows, because kernel context
must not be preempted between a copy/paste pair.

Without this patch, the init task gets used_vas set when it runs the
nx842_powernv_init initcall, which opens windows for kernel usage.

used_vas is then never cleared anywhere, so it gets propagated into
all other tasks. It's a property of the address space, so it should
really be cleared when a new mm is created (or in dup_mmap if the
mmaps are marked as VM_DONTCOPY). For now we seem to have no such
driver, so leave that for another patch.

Fixes: 6c8e6bb2a52d ("powerpc/vas: Add support for user receive window")
Cc: stable@vger.kernel.org # v4.15+
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Reviewed-by: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

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powerpc/vas: Add support for user receive window

Add support for user space receive window (for the Fast thread-wakeup
coprocessor type)

Signed-off-by: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.c

powerpc/vas: Add support for user receive window

Add support for user space receive window (for the Fast thread-wakeup
coprocessor type)

Signed-off-by: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

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powerpc/vas: Define vas_win_id()

Define an interface to return a system-wide unique id for a given VAS
window.

The vas_win_id() will be used in a follow-on patch to generate an unique
handle for a

powerpc/vas: Define vas_win_id()

Define an interface to return a system-wide unique id for a given VAS
window.

The vas_win_id() will be used in a follow-on patch to generate an unique
handle for a user space receive window. Applications can use this handle
to pair send and receive windows for fast thread-wakeup.

The hardware refers to this system-wide unique id as a Partition Send
Window ID which is expected to be used during fault handling. Hence the
"pswid" in the function names.

Signed-off-by: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

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powerpc/vas: Define vas_win_paste_addr()

Define an interface that the NX drivers can use to find the physical
paste address of a send window. This interface is expected to be used
with the mmap() op

powerpc/vas: Define vas_win_paste_addr()

Define an interface that the NX drivers can use to find the physical
paste address of a send window. This interface is expected to be used
with the mmap() operation of the NX driver's device. i.e the user space
process can use driver's mmap() operation to map the send window's paste
address into their address space and then use copy and paste instructions
to submit the CRBs to the NX engine.

Note that kernel drivers will use vas_paste_crb() directly and don't need
this interface.

Signed-off-by: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

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powerpc/vas: Export HVWC to debugfs

Export the VAS Window context information to debugfs.

We need to hold a mutex when closing the window to prevent a race
with the debugfs read(). Rather than intr

powerpc/vas: Export HVWC to debugfs

Export the VAS Window context information to debugfs.

We need to hold a mutex when closing the window to prevent a race
with the debugfs read(). Rather than introduce a per-instance mutex,
we use the global vas_mutex for now, since it is not heavily contended.

The window->cop field is only relevant to a receive window so we were
not setting it for a send window (which is is paired to a receive window
anyway). But to simplify reporting in debugfs, set the 'cop' field for the
send window also.

Signed-off-by: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

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powerpc/vas: poll for return of window credits

Normally, the NX driver waits for the CRBs to be processed before closing
the window. But it is better to ensure that the credits are returned before
t

powerpc/vas: poll for return of window credits

Normally, the NX driver waits for the CRBs to be processed before closing
the window. But it is better to ensure that the credits are returned before
the window gets reassigned later.

Signed-off-by: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

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powerpc/vas: Save configured window credits

Save the configured max window credits for a window in the vas_window
structure. We will need this when polling for return of window credits.

Signed-off-

powerpc/vas: Save configured window credits

Save the configured max window credits for a window in the vas_window
structure. We will need this when polling for return of window credits.

Signed-off-by: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

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powerpc/vas: Reduce polling interval for busy state

A VAS window is normally in "busy" state for only a short duration.
Reduce the time we wait for the window to go to "not-busy" state to
speed-up v

powerpc/vas: Reduce polling interval for busy state

A VAS window is normally in "busy" state for only a short duration.
Reduce the time we wait for the window to go to "not-busy" state to
speed-up vas_win_close() a bit.

Signed-off-by: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

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powerpc/vas: Use helper to unpin/close window

Use a helper to have the hardware unpin and mark a window closed.

Signed-off-by: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
Signed-off-by: Michae

powerpc/vas: Use helper to unpin/close window

Use a helper to have the hardware unpin and mark a window closed.

Signed-off-by: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

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powerpc/vas: Drop poll_window_cast_out().

Polling for window cast out is listed in the spec, but turns out that
it is not strictly necessary and slows down window close. Making it a
stub for now.

S

powerpc/vas: Drop poll_window_cast_out().

Polling for window cast out is listed in the spec, but turns out that
it is not strictly necessary and slows down window close. Making it a
stub for now.

Signed-off-by: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

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powerpc/vas: Cleanup some debug code

Clean up vas.h and the debug code around ifdef vas_debug.

Signed-off-by: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@e

powerpc/vas: Cleanup some debug code

Clean up vas.h and the debug code around ifdef vas_debug.

Signed-off-by: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

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powerpc/vas: Validate window credits

NX-842, the only user of VAS, sets the window credits to default values
but VAS should check the credits against the possible max values.

The VAS_WCREDS_MIN is

powerpc/vas: Validate window credits

NX-842, the only user of VAS, sets the window credits to default values
but VAS should check the credits against the possible max values.

The VAS_WCREDS_MIN is not needed and can be dropped.

Signed-off-by: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

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powerpc/vas: init missing fields from [rt]xattr

Initialize a few missing window context fields from the window attributes
specified by the caller. These fields are currently set to their default
val

powerpc/vas: init missing fields from [rt]xattr

Initialize a few missing window context fields from the window attributes
specified by the caller. These fields are currently set to their default
values by the caller (NX-842), but would be good to apply them anyway.

Signed-off-by: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

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powerpc/powernv/vas: Define copy/paste interfaces

Define interfaces (wrappers) to the 'copy' and 'paste'
instructions (which are new in PowerISA 3.0). These are intended to be
used to by NX driver(s

powerpc/powernv/vas: Define copy/paste interfaces

Define interfaces (wrappers) to the 'copy' and 'paste'
instructions (which are new in PowerISA 3.0). These are intended to be
used to by NX driver(s) to submit Coprocessor Request Blocks (CRBs) to
the NX hardware engines.

Signed-off-by: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

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powerpc/powernv/vas: Define vas_tx_win_open()

Define an interface to open a VAS send window. This interface is
intended to be used the Nest Accelerator (NX) driver(s) to open
a send window and use i

powerpc/powernv/vas: Define vas_tx_win_open()

Define an interface to open a VAS send window. This interface is
intended to be used the Nest Accelerator (NX) driver(s) to open
a send window and use it to submit compression/encryption requests
to a VAS receive window.

The receive window, identified by the [vasid, cop] parameters, must
already be open in VAS (i.e connected to an NX engine).

Signed-off-by: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

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powerpc/powernv/vas: Define vas_win_close() interface

Define the vas_win_close() interface which should be used to close a
send or receive windows.

While the hardware configurations required to ope

powerpc/powernv/vas: Define vas_win_close() interface

Define the vas_win_close() interface which should be used to close a
send or receive windows.

While the hardware configurations required to open send and receive
windows differ, the configuration to close a window is the same for
both. So we use a single interface to close the window.

Signed-off-by: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

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powerpc/powernv/vas: Define vas_rx_win_open() interface

Define the vas_rx_win_open() interface. This interface is intended to
be used by the Nest Accelerator (NX) driver(s) to setup receive
windows

powerpc/powernv/vas: Define vas_rx_win_open() interface

Define the vas_rx_win_open() interface. This interface is intended to
be used by the Nest Accelerator (NX) driver(s) to setup receive
windows for one or more NX engines (which implement compression &
encryption algorithms in the hardware).

Follow-on patches will provide an interface to close the window and to
open a send window that kernel subsystems can use to access the NX
engines.

The interface to open a receive window is expected to be invoked for
each instance of VAS in the system.

Signed-off-by: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

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powerpc/powernv/vas: Define helpers to alloc/free windows

Define helpers to allocate/free VAS window objects. These will be used
in follow-on patches when opening/closing windows.

Signed-off-by: Su

powerpc/powernv/vas: Define helpers to alloc/free windows

Define helpers to allocate/free VAS window objects. These will be used
in follow-on patches when opening/closing windows.

Signed-off-by: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

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powerpc/powernv/vas: Define helpers to init window context

Define helpers to initialize window context registers of the VAS
hardware. These will be used in follow-on patches when opening/closing
VAS

powerpc/powernv/vas: Define helpers to init window context

Define helpers to initialize window context registers of the VAS
hardware. These will be used in follow-on patches when opening/closing
VAS windows.

Signed-off-by: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

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powerpc/powernv/vas: Define helpers to access MMIO regions

Define some helper functions to access the MMIO regions. We use these
in follow-on patches to read/write VAS hardware registers. They are
a

powerpc/powernv/vas: Define helpers to access MMIO regions

Define some helper functions to access the MMIO regions. We use these
in follow-on patches to read/write VAS hardware registers. They are
also used to later issue 'paste' instructions to submit requests to
the NX hardware engines.

Signed-off-by: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

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powerpc/powernv/vas: Define vas_init() and vas_exit()

Implement vas_init() and vas_exit() functions for a new VAS module.
This VAS module is essentially a library for other device drivers
and kernel

powerpc/powernv/vas: Define vas_init() and vas_exit()

Implement vas_init() and vas_exit() functions for a new VAS module.
This VAS module is essentially a library for other device drivers
and kernel users of the NX coprocessors like NX-842 and NX-GZIP.
In the future this will be extended to add support for user space
to access the NX coprocessors.

VAS is currently only supported with 64K page size.

Signed-off-by: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

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powerpc/powernv/vas: Release reference to tgid during window close

commit 91cdbb955aa94ee0841af4685be40937345d29b8 upstream.

The kernel handles the NX fault by updating CSB or sendi

powerpc/powernv/vas: Release reference to tgid during window close

commit 91cdbb955aa94ee0841af4685be40937345d29b8 upstream.

The kernel handles the NX fault by updating CSB or sending
signal to process. In multithread applications, children can
open VAS windows and can exit without closing them. But the
parent can continue to send NX requests with these windows. To
prevent pid reuse, reference will be taken on pid and tgid
when the window is opened and release them during window close.

The current code is not releasing the tgid reference which can
cause pid leak and this patch fixes the issue.

Fixes: db1c08a740635 ("powerpc/vas: Take reference to PID and mm for user space windows")
Cc: stable@vger.kernel.org # 5.8+
Reported-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Haren Myneni <haren@linux.ibm.com>
Reviewed-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/6020fc4d444864fe20f7dcdc5edfe53e67480a1c.camel@linux.ibm.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

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powerpc/powernv: Staticify functions without prototypes

There's a few scattered in the powernv platform.

Signed-off-by: Oliver O'Halloran <oohall@gmail.com>
Reviewed-by: Joel St

powerpc/powernv: Staticify functions without prototypes

There's a few scattered in the powernv platform.

Signed-off-by: Oliver O'Halloran <oohall@gmail.com>
Reviewed-by: Joel Stanley <joel@jms.id.au>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200804005410.146094-4-oohall@gmail.com

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powerpc/vas: Add VAS user space API

On power9, userspace can send GZIP compression requests directly to NX
once kernel establishes NX channel / window with VAS. This patch provides
u

powerpc/vas: Add VAS user space API

On power9, userspace can send GZIP compression requests directly to NX
once kernel establishes NX channel / window with VAS. This patch provides
user space API which allows user space to establish channel using open
VAS_TX_WIN_OPEN ioctl, mmap and close operations.

Each window corresponds to file descriptor and application can open
multiple windows. After the window is opened, VAS_TX_WIN_OPEN icoctl to
open a window on specific VAS instance, mmap() system call to map
the hardware address of engine's request queue into the application's
virtual address space.

Then the application can then submit one or more requests to the the
engine by using the copy/paste instructions and pasting the CRBs to
the virtual address (aka paste_address) returned by mmap().

Only NX GZIP coprocessor type is supported right now and allow GZIP
engine access via /dev/crypto/nx-gzip device node.

Thanks to Michael Ellerman for his changes and suggestions to make the
ioctl generic to support any coprocessor type.

Signed-off-by: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
Signed-off-by: Haren Myneni <haren@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/1587114121.2275.1109.camel@hbabu-laptop

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