Commit Graph

44 Commits

Author SHA1 Message Date
Haren Myneni c127d130f6 powerpc/powernv/vas: Assign real address to rx_fifo in vas_rx_win_attr
In init_winctx_regs(), __pa() is called on winctx->rx_fifo and this
function is called to initialize registers for receive and fault
windows. But the real address is passed in winctx->rx_fifo for
receive windows and the virtual address for fault windows which
causes errors with DEBUG_VIRTUAL enabled. Fixes this issue by
assigning only real address to rx_fifo in vas_rx_win_attr struct
for both receive and fault windows.

Reported-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Haren Myneni <haren@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/338e958c7ab8f3b266fa794a1f80f99b9671829e.camel@linux.ibm.com
2022-05-22 15:58:27 +10:00
Haren Myneni 7bc6f71bdf powerpc/vas: Define and use common vas_window struct
Many elements in vas_struct are used on PowerNV and PowerVM
platforms. vas_window is used for both TX and RX windows on
PowerNV and for TX windows on PowerVM. So some elements are
specific to these platforms.

So this patch defines common vas_window and platform
specific window structs (pnv_vas_window on PowerNV). Also adds
the corresponding changes in PowerNV vas code.

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/1698c35c158dfe52c6d2166667823d3d4a463353.camel@linux.ibm.com
2021-06-20 21:58:56 +10:00
Haren Myneni 3856aa542d powerpc/vas: Create take/drop pid and mm reference functions
Take pid and mm references when each window opens and drops during
close. This functionality is needed for powerNV and pseries. So
this patch defines the existing code as functions in common book3s
platform vas-api.c

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/2fa40df962250a737c804e58202924717b39e381.camel@linux.ibm.com
2021-06-20 21:58:56 +10:00
Haren Myneni 1a0d0d5ed5 powerpc/vas: Add platform specific user window operations
PowerNV uses registers to open/close VAS windows, and getting the
paste address. Whereas the hypervisor calls are used on PowerVM.

This patch adds the platform specific user space window operations
and register with the common VAS user space interface.

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/f85091f4ace67f951ac04d60394d67b21e2f5d3c.camel@linux.ibm.com
2021-06-20 21:58:55 +10:00
Haren Myneni 06c6fad9bf powerpc/powernv/vas: Rename register/unregister functions
powerNV and pseries drivers register / unregister to the corresponding
platform specific VAS separately. Then these VAS functions call the
common API with the specific window operations. So rename powerNV VAS
API register/unregister functions.

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/9db00d58dbdcb7cfc07a1df95f3d2a9e3e5d746a.camel@linux.ibm.com
2021-06-20 21:58:55 +10:00
Haren Myneni 91cdbb955a powerpc/powernv/vas: Release reference to tgid during window close
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: db1c08a740 ("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
2021-06-20 21:58:55 +10:00
Oliver O'Halloran 3b70464aa7 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
2020-08-25 01:31:33 +10:00
Haren Myneni dda44eb29c 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
2020-04-20 16:53:14 +10:00
Haren Myneni a8c0c69b5e powerpc/vas: Initialize window attributes for GZIP coprocessor type
Initialize send and receive window attributes for GZIP high and
normal priority types.

Signed-off-by: Haren Myneni <haren@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/1587114029.2275.1103.camel@hbabu-laptop
2020-04-20 16:53:13 +10:00
Haren Myneni c420644c0a powerpc: Use mm_context vas_windows counter to issue CP_ABORT
set_thread_uses_vas() sets used_vas flag for a process that opened VAS
window and issue CP_ABORT during context switch for only that process.
In multi-thread application, windows can be shared. For example Thread
A can open a window and Thread B can run COPY/PASTE instructions to
send NX request which may cause corruption or snooping or a covert
channel Also once this flag is set, continue to run CP_ABORT even the
VAS window is closed.

So define vas-windows counter in process mm_context, increment this
counter for each window open and decrement it for window close. If
vas-windows is set, issue CP_ABORT during context switch. It means
clear the foreign real address mapping only if the process / thread
uses COPY/PASTE. Then disable it for that process if windows are not
open.

Moved set_thread_uses_vas() code to vas_tx_win_open() as this
functionality is needed only for userspace open windows. We are adding
VAS userspace support along with this fix. So no need to include this
fix in stable releases.

Fixes: 9d2a4d7133 ("powerpc: Define set_thread_uses_vas()")
Signed-off-by: Haren Myneni <haren@linux.ibm.com>
Reported-by: Nicholas Piggin <npiggin@gmail.com>
Suggested-by: Milton Miller <miltonm@us.ibm.com>
Suggested-by: Nicholas Piggin <npiggin@gmail.com>
Reviewed-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/1587017291.2275.1077.camel@hbabu-laptop
2020-04-20 16:53:01 +10:00
Haren Myneni 1d955f9818 powerpc/vas: Free send window in VAS instance after credits returned
NX may be processing requests while trying to close window. Wait until
all credits are returned and then free send window from VAS instance.

Signed-off-by: Haren Myneni <haren@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/1587017256.2275.1076.camel@hbabu-laptop
2020-04-20 16:53:01 +10:00
Haren Myneni bd4da68dbd powerpc/vas: Display process stuck message
Process can not close send window until all requests are processed.
Means wait until window state is not busy and send credits are
returned. Display debug messages in case taking longer to close the
window.

Signed-off-by: Haren Myneni <haren@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/1587017219.2275.1073.camel@hbabu-laptop
2020-04-20 16:53:01 +10:00
Haren Myneni 04f6296ca7 powerpc/vas: Do not use default credits for receive window
System checkstops if RxFIFO overruns with more requests than the
maximum possible number of CRBs allowed in FIFO at any time. So
max credits value (rxattr.wcreds_max) is set and is passed to
vas_rx_win_open() by the the driver.

Signed-off-by: Haren Myneni <haren@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/1587017136.2275.1070.camel@hbabu-laptop
2020-04-20 16:53:01 +10:00
Haren Myneni 461862ef94 powerpc/vas: Return credits after handling fault
NX uses credit mechanism to control the number of requests issued on
a specific window at any point of time. Only send windows and fault
window are used credits. When the request is issued on a given window,
a credit is taken. This credit will be returned after that request is
processed. If credits are not available, returns RMA_Busy for send
window and RMA_Reject for fault window.

NX expects OS to return credit for send window after processing fault
CRB. Also credit has to be returned for fault window after handling
the fault.

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/1587017059.2275.1064.camel@hbabu-laptop
2020-04-20 16:53:00 +10:00
Haren Myneni 9774628acf powerpc/vas: Setup thread IRQ handler per VAS instance
When NX encounters translation error on CRB and any request buffer,
raises an interrupt on the CPU to handle the fault. It can raise one
interrupt for multiple faults. Expects OS to handle these faults and
return credits for fault window after processing faults.

Setup thread IRQ handler and IRQ thread function per each VAS instance.
IRQ handler checks if the thread is already woken up and can handle new
faults. If so returns with IRQ_HANDLED, otherwise wake up thread to
process new faults.

The thread functions reads each CRB entry from fault FIFO until sees
invalid entry. After reading each CRB, determine the corresponding
send window using pswid (from CRB) and process fault CRB. Then
invalidate the entry and return credit. Processing fault CRB and
return credit is described in subsequent patches.

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/1587016982.2275.1060.camel@hbabu-laptop
2020-04-20 16:53:00 +10:00
Haren Myneni db1c08a740 powerpc/vas: Take reference to PID and mm for user space windows
When process opens a window, its pid and tgid will be saved in the
vas_window struct. This window will be closed when the process exits.
The kernel handles NX faults by updating CSB or send SEGV signal to pid
of the process if the userspace csb addr is invalid.

In multi-thread applications, a window can be opened by a child thread,
but it will not be closed when this thread exits. It is expected that
the parent will clean up all resources including NX windows opened by
child threads. A child thread can send NX requests using this window
and could be killed before completion is reported. If the pid assigned
to this thread is reused while requests are pending, a failure SEGV
would be directed to the wrong place.

To prevent reusing the pid, take references to pid and mm when the window
is opened and release them when when the window is closed. Then if child
thread is not running, SEGV signal will be sent to thread group leader
(tgid).

Signed-off-by: Haren Myneni <haren@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/1587016936.2275.1057.camel@hbabu-laptop
2020-04-20 16:53:00 +10:00
Haren Myneni 8b8a73dc79 powerpc/vas: Register NX with fault window ID and IRQ port value
For each user space send window, register NX with fault window ID
and port value so that NX paste CRBs in this fault FIFO when it
sees fault on the request buffer.

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/1587016888.2275.1054.camel@hbabu-laptop
2020-04-20 16:53:00 +10:00
Haren Myneni 0d17de03ce powerpc/vas: Setup fault window per VAS instance
Setup fault window for each VAS instance. When NX gets a fault on
request buffer, pastes fault CRB in the corresponding fault FIFO and
then raises an interrupt to the OS. The kernel handles this fault
and process faults CRB from this FIFO.

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/1587016846.2275.1053.camel@hbabu-laptop
2020-04-20 16:53:00 +10:00
Linus Torvalds 192f0f8e9d powerpc updates for 5.3
Notable changes:
 
  - Removal of the NPU DMA code, used by the out-of-tree Nvidia driver, as well
    as some other functions only used by drivers that haven't (yet?) made it
    upstream.
 
  - A fix for a bug in our handling of hardware watchpoints (eg. perf record -e
    mem: ...) which could lead to register corruption and kernel crashes.
 
  - Enable HAVE_ARCH_HUGE_VMAP, which allows us to use large pages for vmalloc
    when using the Radix MMU.
 
  - A large but incremental rewrite of our exception handling code to use gas
    macros rather than multiple levels of nested CPP macros.
 
 And the usual small fixes, cleanups and improvements.
 
 Thanks to:
   Alastair D'Silva, Alexey Kardashevskiy, Andreas Schwab, Aneesh Kumar K.V, Anju
   T Sudhakar, Anton Blanchard, Arnd Bergmann, Athira Rajeev, Cédric Le Goater,
   Christian Lamparter, Christophe Leroy, Christophe Lombard, Christoph Hellwig,
   Daniel Axtens, Denis Efremov, Enrico Weigelt, Frederic Barrat, Gautham R.
   Shenoy, Geert Uytterhoeven, Geliang Tang, Gen Zhang, Greg Kroah-Hartman, Greg
   Kurz, Gustavo Romero, Krzysztof Kozlowski, Madhavan Srinivasan, Masahiro
   Yamada, Mathieu Malaterre, Michael Neuling, Nathan Lynch, Naveen N. Rao,
   Nicholas Piggin, Nishad Kamdar, Oliver O'Halloran, Qian Cai, Ravi Bangoria,
   Sachin Sant, Sam Bobroff, Satheesh Rajendran, Segher Boessenkool, Shaokun
   Zhang, Shawn Anastasio, Stewart Smith, Suraj Jitindar Singh, Thiago Jung
   Bauermann, YueHaibing.
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Merge tag 'powerpc-5.3-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux

Pull powerpc updates from Michael Ellerman:
 "Notable changes:

   - Removal of the NPU DMA code, used by the out-of-tree Nvidia driver,
     as well as some other functions only used by drivers that haven't
     (yet?) made it upstream.

   - A fix for a bug in our handling of hardware watchpoints (eg. perf
     record -e mem: ...) which could lead to register corruption and
     kernel crashes.

   - Enable HAVE_ARCH_HUGE_VMAP, which allows us to use large pages for
     vmalloc when using the Radix MMU.

   - A large but incremental rewrite of our exception handling code to
     use gas macros rather than multiple levels of nested CPP macros.

  And the usual small fixes, cleanups and improvements.

  Thanks to: Alastair D'Silva, Alexey Kardashevskiy, Andreas Schwab,
  Aneesh Kumar K.V, Anju T Sudhakar, Anton Blanchard, Arnd Bergmann,
  Athira Rajeev, Cédric Le Goater, Christian Lamparter, Christophe
  Leroy, Christophe Lombard, Christoph Hellwig, Daniel Axtens, Denis
  Efremov, Enrico Weigelt, Frederic Barrat, Gautham R. Shenoy, Geert
  Uytterhoeven, Geliang Tang, Gen Zhang, Greg Kroah-Hartman, Greg Kurz,
  Gustavo Romero, Krzysztof Kozlowski, Madhavan Srinivasan, Masahiro
  Yamada, Mathieu Malaterre, Michael Neuling, Nathan Lynch, Naveen N.
  Rao, Nicholas Piggin, Nishad Kamdar, Oliver O'Halloran, Qian Cai, Ravi
  Bangoria, Sachin Sant, Sam Bobroff, Satheesh Rajendran, Segher
  Boessenkool, Shaokun Zhang, Shawn Anastasio, Stewart Smith, Suraj
  Jitindar Singh, Thiago Jung Bauermann, YueHaibing"

* tag 'powerpc-5.3-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: (163 commits)
  powerpc/powernv/idle: Fix restore of SPRN_LDBAR for POWER9 stop state.
  powerpc/eeh: Handle hugepages in ioremap space
  ocxl: Update for AFU descriptor template version 1.1
  powerpc/boot: pass CONFIG options in a simpler and more robust way
  powerpc/boot: add {get, put}_unaligned_be32 to xz_config.h
  powerpc/irq: Don't WARN continuously in arch_local_irq_restore()
  powerpc/module64: Use symbolic instructions names.
  powerpc/module32: Use symbolic instructions names.
  powerpc: Move PPC_HA() PPC_HI() and PPC_LO() to ppc-opcode.h
  powerpc/module64: Fix comment in R_PPC64_ENTRY handling
  powerpc/boot: Add lzo support for uImage
  powerpc/boot: Add lzma support for uImage
  powerpc/boot: don't force gzipped uImage
  powerpc/8xx: Add microcode patch to move SMC parameter RAM.
  powerpc/8xx: Use IO accessors in microcode programming.
  powerpc/8xx: replace #ifdefs by IS_ENABLED() in microcode.c
  powerpc/8xx: refactor programming of microcode CPM params.
  powerpc/8xx: refactor printing of microcode patch name.
  powerpc/8xx: Refactor microcode write
  powerpc/8xx: refactor writing of CPM microcode arrays
  ...
2019-07-13 16:08:36 -07:00
Christoph Hellwig 452d23c0f6 powerpc/powernv: remove the unused vas_win_paste_addr and vas_win_id functions
These two function have never been used anywhere in the kernel tree
since they were added to the kernel.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-07-01 16:26:55 +10:00
Thomas Gleixner 2874c5fd28 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152
Based on 1 normalized pattern(s):

  this program is free software you can redistribute it and or modify
  it under the terms of the gnu general public license as published by
  the free software foundation either version 2 of the license or at
  your option any later version

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-or-later

has been chosen to replace the boilerplate/reference in 3029 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190527070032.746973796@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-30 11:26:32 -07:00
Matthew Wilcox cd38049e48 ppc: Convert vas ID allocation to new IDA API
Removes a custom spinlock and simplifies the code.  Also fix an
error where we could allocate one ID too many.

Signed-off-by: Matthew Wilcox <willy@infradead.org>
2018-08-21 23:54:19 -04:00
Sukadev Bhattiprolu 007bb7d6c7 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>
2018-03-14 20:13:58 +11:00
Nicholas Piggin b00b628986 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: 6c8e6bb2a5 ("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>
2018-02-13 22:37:46 +11:00
Sukadev Bhattiprolu 6c8e6bb2a5 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>
2017-11-12 09:03:10 +11:00
Sukadev Bhattiprolu 61f3cca8cd 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>
2017-11-12 09:03:10 +11:00
Sukadev Bhattiprolu 5676be2fb7 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>
2017-11-12 09:03:10 +11:00
Sukadev Bhattiprolu ece4e51291 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>
2017-11-12 09:03:09 +11:00
Sukadev Bhattiprolu 6fccac16c5 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>
2017-11-12 09:03:08 +11:00
Sukadev Bhattiprolu 62f659e08c 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>
2017-11-12 09:03:07 +11:00
Sukadev Bhattiprolu dfe954e445 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>
2017-11-12 09:03:07 +11:00
Sukadev Bhattiprolu 36a288fe9d 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>
2017-11-12 09:03:07 +11:00
Sukadev Bhattiprolu 4963ac3632 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>
2017-11-12 09:03:06 +11:00
Sukadev Bhattiprolu 0a2c2c24cf 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>
2017-11-12 09:03:06 +11:00
Sukadev Bhattiprolu 51b537124f 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>
2017-11-12 09:03:05 +11:00
Sukadev Bhattiprolu e34917fbee 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>
2017-11-12 09:03:05 +11:00
Sukadev Bhattiprolu 2392c8c8c0 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>
2017-08-31 14:26:38 +10:00
Sukadev Bhattiprolu 5239af679a 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>
2017-08-31 14:26:37 +10:00
Sukadev Bhattiprolu 98271d4198 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>
2017-08-31 14:26:37 +10:00
Sukadev Bhattiprolu 62c4eda4fa 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>
2017-08-31 14:26:36 +10:00
Sukadev Bhattiprolu bbfe59f8a7 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>
2017-08-31 14:26:35 +10:00
Sukadev Bhattiprolu b25b33ac18 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>
2017-08-31 14:26:33 +10:00
Sukadev Bhattiprolu 180fe15a82 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>
2017-08-31 14:26:30 +10:00
Sukadev Bhattiprolu 4dea2d1a92 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>
2017-08-31 14:26:26 +10:00