Commit Graph

26 Commits

Author SHA1 Message Date
Oded Gabbay
541664d360 habanalabs: add comments in uapi/misc/habanalabs.h
Add comment about minimum and maximum size of command buffer.
Add some text about the expected input of CS IOCTL.

Signed-off-by: Oded Gabbay <oded.gabbay@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-02-28 13:06:09 +01:00
Oded Gabbay
230afe74d1 habanalabs: allow memory allocations larger than 4GB
This patch increase the size field in the uapi structure of the Memory
IOCTL from 32-bit to 64-bit. This is to allow the user to allocate and/or
map memory in chunks that are larger then 4GB.

Goya's device memory (DRAM) can be up to 16GB, and for certain
topologies, the user may want an allocation that is larger than 4GB.

This change doesn't break current user-space because there was a "pad"
field in the uapi structure right after the size field. Changing the size
field to be 64-bit and removing the pad field maintains compatibility with
current user-space.

Signed-off-by: Oded Gabbay <oded.gabbay@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-02-27 16:00:20 +01:00
Oded Gabbay
d8dd7b0a81 habanalabs: implement INFO IOCTL
This patch implements the INFO IOCTL. That IOCTL is used by the user to
query information that is relevant/needed by the user in order to submit
deep learning jobs to Goya.

The information is divided into several categories, such as H/W IP, Events
that happened, DDR usage and more.

Reviewed-by: Mike Rapoport <rppt@linux.ibm.com>
Signed-off-by: Oded Gabbay <oded.gabbay@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-02-18 09:46:46 +01:00
Omer Shpigelman
0feaf86d4e habanalabs: add virtual memory and MMU modules
This patch adds the Virtual Memory and MMU modules.

Goya has an internal MMU which provides process isolation on the internal
DDR. The internal MMU also performs translations for transactions that go
from Goya to the Host.

The driver is responsible for allocating and freeing memory on the DDR
upon user request. It also provides an interface to map and unmap DDR and
Host memory to the device address space.

The MMU in Goya supports 3-level and 4-level page tables. With 3-level, the
size of each page is 2MB, while with 4-level the size of each page is 4KB.

In the DDR, the physical pages are always 2MB.

Reviewed-by: Mike Rapoport <rppt@linux.ibm.com>
Signed-off-by: Omer Shpigelman <oshpigelman@habana.ai>
Signed-off-by: Oded Gabbay <oded.gabbay@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-02-18 09:46:46 +01:00
Oded Gabbay
eff6f4a0e7 habanalabs: add command submission module
This patch adds the main flow for the user to submit work to the device.

Each work is described by a command submission object (CS). The CS contains
3 arrays of command buffers: One for execution, and two for context-switch
(store and restore).

For each CB, the user specifies on which queue to put that CB. In case of
an internal queue, the entry doesn't contain a pointer to the CB but the
address in the on-chip memory that the CB resides at.

The driver parses some of the CBs to enforce security restrictions.

The user receives a sequence number that represents the CS object. The user
can then query the driver regarding the status of the CS, using that
sequence number.

In case the CS doesn't finish before the timeout expires, the driver will
perform a soft-reset of the device.

Reviewed-by: Mike Rapoport <rppt@linux.ibm.com>
Signed-off-by: Oded Gabbay <oded.gabbay@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-02-18 09:46:45 +01:00
Oded Gabbay
9494a8dd8d habanalabs: add h/w queues module
This patch adds the H/W queues module and the code to initialize Goya's
various compute and DMA engines and their queues.

Goya has 5 DMA channels, 8 TPC engines and a single MME engine. For each
channel/engine, there is a H/W queue logic which is used to pass commands
from the user to the H/W. That logic is called QMAN.

There are two types of QMANs: external and internal. The DMA QMANs are
considered external while the TPC and MME QMANs are considered internal.
For each external queue there is a completion queue, which is located on
the Host memory.

The differences between external and internal QMANs are:

1. The location of the queue's memory. External QMANs are located on the
   Host memory while internal QMANs are located on the on-chip memory.

2. The external QMAN write an entry to a completion queue and sends an
   MSI-X interrupt upon completion of a command buffer that was given to
   it. The internal QMAN doesn't do that.

Reviewed-by: Mike Rapoport <rppt@linux.ibm.com>
Signed-off-by: Oded Gabbay <oded.gabbay@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-02-18 09:46:45 +01:00
Oded Gabbay
be5d926b5c habanalabs: add command buffer module
This patch adds the command buffer (CB) module, which allows the user to
create and destroy CBs and to map them to the user's process
address-space.

A command buffer is a memory blocks that reside in DMA-able address-space
and is physically contiguous so it can be accessed by the device without
MMU translation. The command buffer memory is allocated using the
coherent DMA API.

When creating a new CB, the IOCTL returns a handle of it, and the
user-space process needs to use that handle to mmap the buffer to get a VA
in the user's address-space.

Before destroying (freeing) a CB, the user must unmap the CB's VA using the
CB handle.

Each CB has a reference counter, which tracks its usage in command
submissions and also its mmaps (only a single mmap is allowed).

The driver maintains a pool of pre-allocated CBs in order to reduce
latency during command submissions. In case the pool is empty, the driver
will go to the slow-path of allocating a new CB, i.e. calling
dma_alloc_coherent.

Reviewed-by: Mike Rapoport <rppt@linux.ibm.com>
Signed-off-by: Oded Gabbay <oded.gabbay@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-02-18 09:46:44 +01:00
Oded Gabbay
99b9d7b497 habanalabs: add basic Goya support
This patch adds a basic support for the Goya device. The code initializes
the device's PCI controller and PCI bars. It also initializes various S/W
structures and adds some basic helper functions.

Reviewed-by: Mike Rapoport <rppt@linux.ibm.com>
Signed-off-by: Oded Gabbay <oded.gabbay@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-02-18 09:46:44 +01:00
Srinivas Kandagatla
6cffd79504 misc: fastrpc: Add support for dmabuf exporter
User process can involve dealing with big buffer sizes, and also passing
buffers from one compute context bank to other compute context bank for
complex dsp algorithms.

This patch adds support to fastrpc to make it a proper dmabuf exporter
to avoid making copies of buffers.

Co-developed-by: Thierry Escande <thierry.escande@linaro.org>
Signed-off-by: Thierry Escande <thierry.escande@linaro.org>
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-02-12 10:40:30 +01:00
Srinivas Kandagatla
d73f71c7c6 misc: fastrpc: Add support for create remote init process
This patch adds support to create or attach remote shell process.
The shell process called fastrpc_shell_0 is usually loaded on the DSP
when a user process is spawned.

Most of the work is derived from various downstream Qualcomm kernels.
Credits to various Qualcomm authors who have contributed to this code.
Specially Tharun Kumar Merugu <mtharu@codeaurora.org>

Co-developed-by: Thierry Escande <thierry.escande@linaro.org>
Signed-off-by: Thierry Escande <thierry.escande@linaro.org>
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-02-12 10:40:30 +01:00
Srinivas Kandagatla
c68cfb718c misc: fastrpc: Add support for context Invoke method
This patch adds support to compute context invoke method on the
remote processor (DSP).
This involves setting up the functions input and output arguments,
input and output handles and mapping the dmabuf fd for the
argument/handle buffers.

The below diagram depicts invocation of a single method where the
client and objects reside on different processors. An object could
expose multiple methods which can be grouped together and referred
to as an interface.

,--------,        ,------,  ,-----------,  ,------,        ,--------,
|        | method |      |  |           |  |      | method |        |
| Client |------->| Stub |->| Transport |->| Skel |------->| Object |
|        |        |      |  |           |  |      |        |        |
`--------`        `------`  `-----------`  `------`        `--------`

Client:    Linux user mode process that initiates the remote invocation
Stub:      Auto generated code linked in with the user mode process that
           takes care of marshaling parameters
Transport: Involved in carrying an invocation from a client to an
           object. This involves two portions: 1) FastRPC Linux
           kernel driver that receives the remote invocation, queues
           them up and then waits for the response after signaling the
           remote side. 2) Service running on the remote side that
           dequeues the messages from the queue and dispatches them for
           processing.
Skel:      Auto generated code that takes care of un-marshaling
           parameters
Object:    Method implementation

Most of the work is derived from various downstream Qualcomm kernels.
Credits to various Qualcomm authors who have contributed to this code.
Specially Tharun Kumar Merugu <mtharu@codeaurora.org>

Co-developed-by: Thierry Escande <thierry.escande@linaro.org>
Signed-off-by: Thierry Escande <thierry.escande@linaro.org>
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-02-12 10:40:30 +01:00
Alastair D'Silva
02a8e5bc1c ocxl: Add an IOCTL so userspace knows what OCXL features are available
In order for a userspace AFU driver to call the POWER9 specific
OCXL_IOCTL_ENABLE_P9_WAIT, it needs to verify that it can actually
make that call.

Signed-off-by: Alastair D'Silva <alastair@d-silva.org>
Acked-by: Frederic Barrat <fbarrat@linux.vnet.ibm.com>
Acked-by: Andrew Donnellan <andrew.donnellan@au1.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-06-03 20:40:32 +10:00
Alastair D'Silva
e948e06fc6 ocxl: Expose the thread_id needed for wait on POWER9
In order to successfully issue as_notify, an AFU needs to know the TID
to notify, which in turn means that this information should be
available in userspace so it can be communicated to the AFU.

Signed-off-by: Alastair D'Silva <alastair@d-silva.org>
Acked-by: Andrew Donnellan <andrew.donnellan@au1.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-06-03 20:40:32 +10:00
Alastair D'Silva
07c5ccd70a ocxl: Add get_metadata IOCTL to share OCXL information to userspace
Some required information is not exposed to userspace currently (eg. the
PASID), pass this information back, along with other information which
is currently communicated via sysfs, which saves some parsing effort in
userspace.

Signed-off-by: Alastair D'Silva <alastair@d-silva.org>
Acked-by: Andrew Donnellan <andrew.donnellan@au1.ibm.com>
Acked-by: Frederic Barrat <fbarrat@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-03-02 13:02:14 +11:00
Frederic Barrat
aeddad1760 ocxl: Add AFU interrupt support
Add user APIs through ioctl to allocate, free, and be notified of an
AFU interrupt.

For opencapi, an AFU can trigger an interrupt on the host by sending a
specific command targeting a 64-bit object handle. On POWER9, this is
implemented by mapping a special page in the address space of a
process and a write to that page will trigger an interrupt.

Signed-off-by: Frederic Barrat <fbarrat@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-01-24 11:42:58 +11:00
Frederic Barrat
5ef3166e8a ocxl: Driver code for 'generic' opencapi devices
Add an ocxl driver to handle generic opencapi devices. Of course, it's
not meant to be the only opencapi driver, any device is free to
implement its own. But if a host application only needs basic services
like attaching to an opencapi adapter, have translation faults handled
or allocate AFU interrupts, it should suffice.

The AFU config space must follow the opencapi specification and use
the expected vendor/device ID to be seen by the generic driver.

The driver exposes the device AFUs as a char device in /dev/ocxl/

Note that the driver currently doesn't handle memory attached to the
opencapi device.

Signed-off-by: Frederic Barrat <fbarrat@linux.vnet.ibm.com>
Signed-off-by: Andrew Donnellan <andrew.donnellan@au1.ibm.com>
Signed-off-by: Alastair D'Silva <alastair@d-silva.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-01-24 11:42:58 +11:00
Christophe Lombard
b1db551324 cxl: Add support for ASB_Notify on POWER9
The POWER9 core supports a new feature: ASB_Notify which requires the
support of the Special Purpose Register: TIDR.

The ASB_Notify command, generated by the AFU, will attempt to
wake-up the host thread identified by the particular LPID:PID:TID.

This patch assign a unique TIDR (thread id) for the current thread which
will be used in the process element entry.

Signed-off-by: Christophe Lombard <clombard@linux.vnet.ibm.com>
Reviewed-by: Philippe Bergheaud <felix@linux.vnet.ibm.com>
Acked-by: Frederic Barrat <fbarrat@linux.vnet.ibm.com>
Reviewed-by: Vaibhav Jain <vaibhav@linux.vnet.ibm.com>
Acked-by: Andrew Donnellan <andrew.donnellan@au1.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-01-19 23:19:37 +11:00
Greg Kroah-Hartman
e2be04c7f9 License cleanup: add SPDX license identifier to uapi header files with a license
Many user space API headers have licensing information, which is either
incomplete, badly formatted or just a shorthand for referring to the
license under which the file is supposed to be.  This makes it hard for
compliance tools to determine the correct license.

Update these files with an SPDX license identifier.  The identifier was
chosen based on the license information in the file.

GPL/LGPL licensed headers get the matching GPL/LGPL SPDX license
identifier with the added 'WITH Linux-syscall-note' exception, which is
the officially assigned exception identifier for the kernel syscall
exception:

   NOTE! This copyright does *not* cover user programs that use kernel
   services by normal system calls - this is merely considered normal use
   of the kernel, and does *not* fall under the heading of "derived work".

This exception makes it possible to include GPL headers into non GPL
code, without confusing license compliance tools.

Headers which have either explicit dual licensing or are just licensed
under a non GPL license are updated with the corresponding SPDX
identifier and the GPLv2 with syscall exception identifier.  The format
is:
        ((GPL-2.0 WITH Linux-syscall-note) OR SPDX-ID-OF-OTHER-LICENSE)

SPDX license identifiers are a legally binding shorthand, which can be
used instead of the full boiler plate text.  The update does not remove
existing license information as this has to be done on a case by case
basis and the copyright holders might have to be consulted. This will
happen in a separate step.

This patch is based on work done by Thomas Gleixner and Kate Stewart and
Philippe Ombredanne.  See the previous patch in this series for the
methodology of how this patch was researched.

Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-11-02 11:20:11 +01:00
Nicolas Dichtel
fcc8487d47 uapi: export all headers under uapi directories
Regularly, when a new header is created in include/uapi/, the developer
forgets to add it in the corresponding Kbuild file. This error is usually
detected after the release is out.

In fact, all headers under uapi directories should be exported, thus it's
useless to have an exhaustive list.

After this patch, the following files, which were not exported, are now
exported (with make headers_install_all):
asm-arc/kvm_para.h
asm-arc/ucontext.h
asm-blackfin/shmparam.h
asm-blackfin/ucontext.h
asm-c6x/shmparam.h
asm-c6x/ucontext.h
asm-cris/kvm_para.h
asm-h8300/shmparam.h
asm-h8300/ucontext.h
asm-hexagon/shmparam.h
asm-m32r/kvm_para.h
asm-m68k/kvm_para.h
asm-m68k/shmparam.h
asm-metag/kvm_para.h
asm-metag/shmparam.h
asm-metag/ucontext.h
asm-mips/hwcap.h
asm-mips/reg.h
asm-mips/ucontext.h
asm-nios2/kvm_para.h
asm-nios2/ucontext.h
asm-openrisc/shmparam.h
asm-parisc/kvm_para.h
asm-powerpc/perf_regs.h
asm-sh/kvm_para.h
asm-sh/ucontext.h
asm-tile/shmparam.h
asm-unicore32/shmparam.h
asm-unicore32/ucontext.h
asm-x86/hwcap2.h
asm-xtensa/kvm_para.h
drm/armada_drm.h
drm/etnaviv_drm.h
drm/vgem_drm.h
linux/aspeed-lpc-ctrl.h
linux/auto_dev-ioctl.h
linux/bcache.h
linux/btrfs_tree.h
linux/can/vxcan.h
linux/cifs/cifs_mount.h
linux/coresight-stm.h
linux/cryptouser.h
linux/fsmap.h
linux/genwqe/genwqe_card.h
linux/hash_info.h
linux/kcm.h
linux/kcov.h
linux/kfd_ioctl.h
linux/lightnvm.h
linux/module.h
linux/nbd-netlink.h
linux/nilfs2_api.h
linux/nilfs2_ondisk.h
linux/nsfs.h
linux/pr.h
linux/qrtr.h
linux/rpmsg.h
linux/sched/types.h
linux/sed-opal.h
linux/smc.h
linux/smc_diag.h
linux/stm.h
linux/switchtec_ioctl.h
linux/vfio_ccw.h
linux/wil6210_uapi.h
rdma/bnxt_re-abi.h

Note that I have removed from this list the files which are generated in every
exported directories (like .install or .install.cmd).

Thanks to Julien Floret <julien.floret@6wind.com> for the tip to get all
subdirs with a pure makefile command.

For the record, note that exported files for asm directories are a mix of
files listed by:
 - include/uapi/asm-generic/Kbuild.asm;
 - arch/<arch>/include/uapi/asm/Kbuild;
 - arch/<arch>/include/asm/Kbuild.

Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Acked-by: Russell King <rmk+kernel@armlinux.org.uk>
Acked-by: Mark Salter <msalter@redhat.com>
Acked-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc)
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2017-05-11 00:21:54 +09:00
Philippe Bergheaud
cbd74e1bc8 cxl: Use fixed width predefined types in data structure.
This patch fixes a regression introduced by commit b810253bd9 ("cxl:
Add mechanism for delivering AFU driver specific events").

It changes the type u8 to __u8 in the uapi header cxl.h, because the
former is a kernel internal type, and may not be defined in userland
build environments, in particular when cross-compiling libcxl on x86_64
linux machines (RHEL6.7 and Ubuntu 16.04).

This patch also changes the size of the field data_size, and makes it
constant, to support 32-bit userland applications running on big-endian
ppc64 kernels transparently.

mpe: This is an ABI change, however the ABI was only added during the
4.8 merge window so has never been part of a released kernel - therefore
we give ourselves permission to change it.

Fixes: b810253bd9 ("cxl: Add mechanism for delivering AFU driver specific events")
Signed-off-by: Philippe Bergheaud <felix@linux.vnet.ibm.com>
Reviewed-by: Frederic Barrat <fbarrat@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-08-09 16:52:01 +10:00
Philippe Bergheaud
b810253bd9 cxl: Add mechanism for delivering AFU driver specific events
This adds an afu_driver_ops structure with fetch_event() and
event_delivered() callbacks. An AFU driver such as cxlflash can fill
this out and associate it with a context to enable passing custom AFU
specific events to userspace.

This also adds a new kernel API function cxl_context_pending_events(),
that the AFU driver can use to notify the cxl driver that new specific
events are ready to be delivered, and wake up anyone waiting on the
context wait queue.

The current count of AFU driver specific events is stored in the field
afu_driver_events of the context structure.

The cxl driver checks the afu_driver_events count during poll, select,
read, etc. calls to check if an AFU driver specific event is pending,
and calls fetch_event() to obtain and deliver that event. This way, the
cxl driver takes care of all the usual locking semantics around these
calls and handles all the generic cxl events, so that the AFU driver
only needs to worry about it's own events.

fetch_event() return a struct cxl_event_afu_driver_reserved, allocated
by the AFU driver, and filled in with the specific event information and
size. Total event size (header + data) should not be greater than
CXL_READ_MIN_SIZE (4K).

Th cxl driver prepends an appropriate cxl event header, copies the event
to userspace, and finally calls event_delivered() to return the status of
the operation to the AFU driver. The event is identified by the context
and cxl_event_afu_driver_reserved pointers.

Since AFU drivers provide their own means for userspace to obtain the
AFU file descriptor (i.e. cxlflash uses an ioctl on their scsi file
descriptor to obtain the AFU file descriptor) and the generic cxl driver
will never use this event, the ABI of the event is up to each individual
AFU driver.

Signed-off-by: Philippe Bergheaud <felix@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-06-28 18:34:56 +10:00
Christophe Lombard
594ff7d067 cxl: Support to flash a new image on the adapter from a guest
The new flash.c file contains the logic to flash a new image on the
adapter, through a hcall. It is an iterative process, with chunks of
data of 1M at a time. There are also 2 phases: write and verify. The
flash operation itself is driven from a user-land tool.
Once flashing is successful, an rtas call is made to update the device
tree with the new properties values for the adapter and the AFU(s)

Add a new char device for the adapter, so that the flash tool can
access the card, even if there is no valid AFU on it.

Co-authored-by: Frederic Barrat <fbarrat@linux.vnet.ibm.com>
Signed-off-by: Frederic Barrat <fbarrat@linux.vnet.ibm.com>
Signed-off-by: Christophe Lombard <clombard@linux.vnet.ibm.com>
Reviewed-by: Manoj Kumar <manoj@linux.vnet.ibm.com>
Acked-by: Ian Munsie <imunsie@au1.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-03-09 23:39:56 +11:00
Ian Munsie
d9232a3da8 cxl: Add alternate MMIO error handling
userspace programs using cxl currently have to use two strategies for
dealing with MMIO errors simultaneously. They have to check every read
for a return of all Fs in case the adapter has gone away and the kernel
has not yet noticed, and they have to deal with SIGBUS in case the
kernel has already noticed, invalidated the mapping and marked the
context as failed.

In order to simplify things, this patch adds an alternative approach
where the kernel will return a page filled with Fs instead of delivering
a SIGBUS. This allows userspace to only need to deal with one of these
two error paths, and is intended for use in libraries that use cxl
transparently and may not be able to safely install a signal handler.

This approach will only work if certain constraints are met. Namely, if
the application is both reading and writing to an address in the problem
state area it cannot assume that a non-FF read is OK, as it may just be
reading out a value it has previously written. Further - since only one
page is used per context a write to a given offset would be visible when
reading the same offset from a different page in the mapping (this only
applies within a single context, not between contexts).

An application could deal with this by e.g. making sure it also reads
from a read-only offset after any reads to a read/write offset.

Due to these constraints, this functionality must be explicitly
requested by userspace when starting the context by passing in the
CXL_START_WORK_ERR_FF flag.

Signed-off-by: Ian Munsie <imunsie@au1.ibm.com>
Acked-by: Michael Neuling <mikey@neuling.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-08-18 19:34:43 +10:00
Vaibhav Jain
27d4dc7116 cxl: Implement an ioctl to fetch afu card-id, offset-id and mode
Given a file descriptor on an afu device, libcxl currently uses the
major/minor number obtained from fstat on the fd to construct path to
the afu's sysfs directory. However it is possible that rather than using
one of the device in /dev/cxl, a kernel driver creates its own device
which export generic cxl interface to the userspace. This causes
problems with libcxl as it tries to use a wrong major/minor number to
construct the sysfs path and fail.

So this patch introduces a new ioctl called CXL_IOCTL_GET_AFU_ID on the
afu file descriptor to fetch the cxl_afu_id struct that holds the
card/offset-id and mode information. These info is then used by libcxl to
construct the correct path to the afu sysfs directory.

Testing:
	- Build against pseries be/le configs
	- Testing with corresponding libcxl changes to verify that it constructs
	  right sysfs path to the afu.

Signed-off-by: Vaibhav Jain <vaibhav@linux.vnet.ibm.com>
Acked-by: Ian Munsie <imunsie@au1.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-06-03 13:27:15 +10:00
Ian Munsie
a9282d01cf cxl: Add documentation for userspace APIs
This documentation gives an overview of the hardware architecture, userspace
APIs via /dev/cxl/afuM.N and the syfs files. It also adds a MAINTAINERS file
entry for cxl.

Signed-off-by: Ian Munsie <imunsie@au1.ibm.com>
Signed-off-by: Michael Neuling <mikey@neuling.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2014-10-08 20:16:19 +11:00
Ian Munsie
66b43081c0 cxl: Add userspace header file
This adds a header file for use by userspace programs wanting to interact with
the kernel cxl driver.  It defines structs and magic numbers required for
userspace to interact with devices in /dev/cxl/afuM.N.

Further documentation on this interface is added in a subsequent patch in
Documentation/powerpc/cxl.txt.

It also adds this new userspace header file to Kbuild so it's exported when
doing "make headers_installs".

Signed-off-by: Ian Munsie <imunsie@au1.ibm.com>
Signed-off-by: Michael Neuling <mikey@neuling.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2014-10-08 20:15:57 +11:00