Commit graph

34 commits

Author SHA1 Message Date
Christophe JAILLET
3a15b45b54 cxl: Fix a memory leak in an error handling path
A bitmap_zalloc() must be balanced by a corresponding bitmap_free() in the
error handling path of afu_allocate_irqs().

Acked-by: Andrew Donnellan <ajd@linux.ibm.com>
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Link: https://lore.kernel.org/r/ce5869418f5838187946eb6b11a52715a93ece3d.1657566849.git.christophe.jaillet@wanadoo.fr
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-07-14 16:53:52 +02:00
Christophe JAILLET
4b00b176b3 cxl: Use the bitmap API to allocate bitmaps
Use bitmap_zalloc()/bitmap_free() instead of hand-writing them.

It is less verbose and it improves the semantic.

Acked-by: Andrew Donnellan <ajd@linux.ibm.com>
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Link: https://lore.kernel.org/r/59010cc7c62443030c69cb1ce0b2b62c5d47e064.1657566849.git.christophe.jaillet@wanadoo.fr
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-07-14 16:53:52 +02:00
Christophe Leroy
d8d2af70b9 cxl/ocxl: Prepare cleanup of powerpc's asm/prom.h
powerpc's asm/prom.h brings some headers that it doesn't
need itself.

In order to clean it up, first add missing headers in
users of asm/prom.h

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Acked-by: Frederic Barrat <fbarrat@linux.ibm.com>
Acked-by: Andrew Donnellan <ajd@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/a2bae89b280e7a7cb87889635d9911d6a245e780.1648833388.git.christophe.leroy@csgroup.eu
2022-05-11 23:06:39 +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
Christophe Lombard
f24be42aab cxl: Add psl9 specific code
The new Coherent Accelerator Interface Architecture, level 2, for the
IBM POWER9 brings new content and features:
- POWER9 Service Layer
- Registers
- Radix mode
- Process element entry
- Dedicated-Shared Process Programming Model
- Translation Fault Handling
- CAPP
- Memory Context ID
    If a valid mm_struct is found the memory context id is used for each
    transaction associated with the process handle. The PSL uses the
    context ID to find the corresponding process element.

Signed-off-by: Christophe Lombard <clombard@linux.vnet.ibm.com>
Acked-by: Frederic Barrat <fbarrat@linux.vnet.ibm.com>
[mpe: Fixup comment formatting, unsplit long strings]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-04-13 23:34:31 +10:00
Christophe Lombard
64663f372c cxl: Rename some psl8 specific functions
Rename a few functions, changing the '_psl' suffix to '_psl8', to make
clear that the implementation is psl8 specific.
Those functions will have an equivalent implementation for the psl9 in
a later patch.

Signed-off-by: Christophe Lombard <clombard@linux.vnet.ibm.com>
Reviewed-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>
2017-04-13 23:34:30 +10:00
Christophe Lombard
bdd2e71506 cxl: Update implementation service layer
The service layer API (in cxl.h) lists some low-level functions whose
implementation is different on PSL8, PSL9 and XSL:
- Init implementation for the adapter and the afu.
- Invalidate TLB/SLB.
- Attach process for dedicated/directed models.
- Handle psl interrupts.
- Debug registers for the adapter and the afu.
- Traces.
Each environment implements its own functions, and the common code uses
them through function pointers, defined in cxl_service_layer_ops.

Signed-off-by: Christophe Lombard <clombard@linux.vnet.ibm.com>
Reviewed-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>
2017-04-13 23:34:29 +10:00
Andrew Donnellan
3382a6220f cxl: Fix coccinelle warnings
Fix the following coccinelle warnings:

  drivers/misc/cxl/debugfs.c:46:0-23: WARNING: fops_io_x64 should be
      defined with DEFINE_DEBUGFS_ATTRIBUTE
  drivers/misc/cxl/guest.c:890:5-26: WARNING: Comparison to bool
  drivers/misc/cxl/irq.c:107:3-23: WARNING: Assignment of bool to 0/1
  drivers/misc/cxl/native.c:57:2-3: Unneeded semicolon
  drivers/misc/cxl/native.c:170:2-3: Unneeded semicolon

Signed-off-by: Andrew Donnellan <andrew.donnellan@au1.ibm.com>
Acked-by: Frederic Barrat <fbarrat@linux.vnet.ibm.com>
Reviewed-by: Matthew R. Ochs <mrochs@linux.vnet.ibm.com>
Acked-by: Ian Munsie <imunsie@au1.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-11-23 22:57:49 +11:00
Philippe Bergheaud
6e0c50f9e8 cxl: Refine slice error debug messages
The PSL Slice Error Register (PSL_SERR_An) reports implementation
dependent AFU errors, in the form of a bitmap. The PSL_SERR_An
register content is printed in the form of hex dump debug message.

This patch decodes the PSL_ERR_An register contents, and prints a
specific error message for each possible error bit. It also dumps
the secondary registers AFU_ERR_An and PSL_DSISR_An, that may
contain extra debug information.

This patch also removes the large WARN message that used to report
the cxl slice error interrupt, and replaces it by a short informative
message, that draws attention to AFU implementation errors.

Signed-off-by: Philippe Bergheaud <felix@linux.vnet.ibm.com>
Acked-by: Ian Munsie <imunsie@au1.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-07-08 22:22:03 +10:00
Ian Munsie
f5c9df9a44 cxl: Fix NULL pointer dereference on kernel contexts with no AFU interrupts
If a kernel context is initialised and does not have any AFU interrupts
allocated it will cause a NULL pointer dereference when the context is
detached since the irq_names list will not have been initialised.

Move the initialisation of the irq_names list into the cxl_context_init
routine so that it will be valid for the entire lifetime of the context
and will not cause a NULL pointer dereference.

Signed-off-by: Ian Munsie <imunsie@au1.ibm.com>
Reviewed-by: Andrew Donnellan <andrew.donnellan@au1.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-07-08 22:13:34 +10:00
Michael Neuling
d6776bba44 cxl: Keep IRQ mappings on context teardown
Keep IRQ mappings on context teardown.  This won't leak IRQs as if we
allocate the mapping again, the generic code will give the same
mapping used last time.

Doing this works around a race in the generic code. Masking the
interrupt introduces a race which can crash the kernel or result in
IRQ that is never EOIed. The lost of EOI results in all subsequent
mappings to the same HW IRQ never receiving an interrupt.

We've seen this race with cxl test cases which are doing heavy context
startup and teardown at the same time as heavy interrupt load.

A fix to the generic code is being investigated also.

Signed-off-by: Michael Neuling <mikey@neuling.org>
Cc: stable@vger.kernel.org # 3.8
Tested-by: Andrew Donnellan <andrew.donnellan@au1.ibm.com>
Acked-by: Ian Munsie <imunsie@au1.ibm.com>
Tested-by: Vaibhav Jain <vaibhav@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-04-27 12:04:31 +10:00
Christophe Lombard
cbffa3a514 cxl: Separate bare-metal fields in adapter and AFU data structures
Introduce sub-structures containing the bare-metal specific fields in
the structures describing the adapter (struct cxl) and AFU (struct
cxl_afu).
Update all their references.

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 13:05:54 +11:00
Frederic Barrat
73d55c3b59 cxl: IRQ allocation for guests
The PSL interrupt cannot be multiplexed in a guest, as it is not
supported by the hypervisor. So an interrupt will be allocated
for it for each context. It will still be the first interrupt found in
the first interrupt range, but is treated almost like any other AFU
interrupt when creating/deleting the context. Only the handler is
different. Rework the code so that the range 0 is treated like the
other ranges.

Co-authored-by: Christophe Lombard <clombard@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 13:05:50 +11:00
Frederic Barrat
6d625ed9a7 cxl: Update cxl_irq() prototype
The context parameter when calling cxl_irq() should be strongly typed.

Co-authored-by: Christophe Lombard <clombard@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 13:05:49 +11:00
Frederic Barrat
5be587b111 cxl: Introduce implementation-specific API
The backend API (in cxl.h) lists some low-level functions whose
implementation is different on bare-metal and in a guest. Each
environment implements its own functions, and the common code uses
them through function pointers, defined in cxl_backend_ops

Co-authored-by: Christophe Lombard <clombard@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 13:05:43 +11:00
Frederic Barrat
d56d301b51 cxl: Move bare-metal specific code to specialized files
Move a few functions around to better separate code specific to
bare-metal environment from code which will be commonly used between
guest and bare-metal.

Code specific to bare-metal is meant to be in native.c or pci.c
only. It's basically anything which touches the card p1 registers,
some p2 registers not needed from a guest and the PCI interface.

Co-authored-by: Christophe Lombard <clombard@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 13:05:39 +11:00
Christophe Lombard
8633186209 cxl: Move common code away from bare-metal-specific files
Move around some functions which will be accessed from the bare-metal
and guest environments.
Code in native.c and pci.c is meant to be bare-metal specific.
Other files contain code which may be shared with guests.

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 13:05:37 +11:00
Andrew Donnellan
52adee580d cxl: fix leak of ctx->irq_bitmap when releasing context via kernel API
At present, ctx->irq_bitmap is freed in afu_release_irqs(), which is called
from afu_release() via cxl_context_detach().

Move the freeing of ctx->irq_bitmap from afu_release_irqs() to
reclaim_ctx() (called through cxl_context_free()) so it's freed when
releasing a context via the kernel API (cxl_release_context()) or the
userspace API (afu_release()).

Reported-by: Matthew R. Ochs <mrochs@linux.vnet.ibm.com>
Fixes: 6f7f0b3df6 ("cxl: Add AFU virtual PHB and kernel API")
Signed-off-by: Andrew Donnellan <andrew.donnellan@au1.ibm.com>
Acked-by: Ian Munsie <imunsie@au1.ibm.com>
Reviewed-by: Matthew R. Ochs <mrochs@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-10-01 11:49:32 +10:00
Andrew Donnellan
8dde152ea3 cxl: fix leak of IRQ names in cxl_free_afu_irqs()
cxl_free_afu_irqs() doesn't free IRQ names when it releases an AFU's IRQ
ranges. The userspace API equivalent in afu_release_irqs() calls
afu_irq_name_free() to release the IRQ names.

Call afu_irq_name_free() in cxl_free_afu_irqs() to release the IRQ names.
Make afu_irq_name_free() non-static to allow this.

Reported-by: Matthew R. Ochs <mrochs@linux.vnet.ibm.com>
Fixes: 6f7f0b3df6 ("cxl: Add AFU virtual PHB and kernel API")
Signed-off-by: Andrew Donnellan <andrew.donnellan@au1.ibm.com>
Signed-off-by: Ian Munsie <imunsie@au1.ibm.com>
Reviewed-by: Matthew R. Ochs <mrochs@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-10-01 11:49:32 +10:00
Vaibhav Jain
a6897f3966 cxl: Release irqs if memory allocation fails
This minor patch plugs a potential irq leak in case of a memory
allocation failure inside function the afu_allocate_irqs. Presently the
irqs allocated to the context gets leaked if allocation of either
one of context irq_bitmap or irq_names fails.

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>
2015-08-27 13:51:18 +10:00
Vaibhav Jain
8c7dd08a8c cxl: Plug irq_bitmap getting leaked in cxl_context
This patch plugs the leak of irq_bitmap, allocated as part of
initialization of cxl_context struct; during the call to
afu_allocate_irqs. The bitmap is now release during the call to function
afu_release_irqs.

Reported-by: Matthew R. Ochs <mrochs@linux.vnet.ibm.com>
Signed-off-by: Vaibhav Jain <vaibhav@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-08-17 13:56:32 +10:00
Daniel Axtens
e640d2fc81 cxl: Make IRQ release idempotent
Check if an IRQ is mapped before releasing it.

This will simplify future EEH code by allowing unconditional unmapping
of IRQs.

Acked-by: Cyril Bur <cyrilbur@gmail.com>
Signed-off-by: Daniel Axtens <dja@axtens.net>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-08-14 21:32:04 +10:00
Daniel Axtens
3d6b040e73 cxl: sparse: Make declarations static
A few declarations were identified by sparse as needing to be static:

  drivers/misc/cxl/irq.c:408:6: warning: symbol 'afu_irq_name_free' was not declared. Should it be static?
  drivers/misc/cxl/irq.c:467:6: warning: symbol 'afu_register_hwirqs' was not declared. Should it be static?
  drivers/misc/cxl/file.c:254:6: warning: symbol 'afu_compat_ioctl' was not declared. Should it be static?
  drivers/misc/cxl/file.c:399:30: warning: symbol 'afu_master_fops' was not declared. Should it be static?

Make them static.

Signed-off-by: Daniel Axtens <dja@axtens.net>
Acked-by: Michael Neuling <mikey@neuling.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-08-12 14:49:09 +10:00
Rasmus Villemoes
de36953843 cxl: use more common format specifier
A precision of 16 (%.16llx) has the same effect as a field width of 16
along with passing the 0 flag (%016llx), but the latter is much more
common in the kernel tree. Update cxl to use that.

Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Acked-by: Ian Munsie <imunsie@au1.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-07-13 10:10:54 +10:00
Rasmus Villemoes
80c394fab8 cxl: Add explicit precision specifiers
C99 says that a precision given as simply '.' with no following digits
or * should be interpreted as 0. The kernel's printf implementation,
however, treats this case as if the precision was omitted. C99 also
says that if both the precision and value are 0, no digits should be
printed. Even if the kernel followed C99 to the letter, I don't think
that would be particularly useful in these cases. For consistency with
most other format strings in the file, use an explicit precision of 16
and add a 0x prefix.

Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-07-13 10:10:54 +10:00
Michael Neuling
ec249dd860 cxl: Move include file cxl.h -> cxl-base.h
This moves the current include file from cxl.h -> cxl-base.h.  This current
include file is used only to pass information between the base driver that
needs to be built into the kernel and the cxl module.

This is to make way for a new include/misc/cxl.h which will
contain just the kernel API for other driver to use

Signed-off-by: Michael Neuling <mikey@neuling.org>
Acked-by: Ian Munsie <imunsie@au1.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-06-03 13:27:19 +10:00
Michael Neuling
c358d84b4e cxl: Split afu_register_irqs() function
Split the afu_register_irqs() function so that different parts can
be useful elsewhere.

Signed-off-by: Michael Neuling <mikey@neuling.org>
Acked-by: Ian Munsie <imunsie@au1.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-06-03 13:27:19 +10:00
Michael Neuling
6428832a7b cxl: Add cookie parameter to afu_release_irqs()
Add cookie parameter to afu_release_irqs() so that we can pass in a different
cookie than the context structure.  This will be useful for other kernel
drivers that want to call this but get their own cookie back in the interrupt
handler.

Update all existing call sites.

Signed-off-by: Michael Neuling <mikey@neuling.org>
Acked-by: Ian Munsie <imunsie@au1.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-06-03 13:27:17 +10:00
Ian Munsie
a6130ed253 cxl: Add missing return statement after handling AFU errror
We were missing a return statement in the PSL interrupt handler in the
case of an AFU error, which would trigger an "Unhandled CXL PSL IRQ"
warning. We do actually handle these type of errors (by notifying
userspace), so add the missing return IRQ_HANDLED so we don't throw
unecessary warnings.

Signed-off-by: Ian Munsie <imunsie@au1.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-02-06 11:17:27 +11:00
Ian Munsie
9bcf28cdb2 cxl: Add tracepoints
This patch adds tracepoints throughout the cxl driver, which can provide
insight into:

- Context lifetimes
- Commands sent to the PSL and AFU and their completion status
- Segment and page table misses and their resolution
- PSL and AFU interrupts
- slbia calls from the powerpc copro_fault code

These tracepoints are mostly intended to aid in debugging (particularly
for new AFU designs), and may be useful standalone or in conjunction
with hardware traces collected by the PSL (read out via the trace
interface in debugfs) and AFUs.

Signed-off-by: Ian Munsie <imunsie@au1.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-01-22 17:31:51 +11:00
Colin Ian King
d3383aaae9 cxl: remove redundant increment of hwirq
hwirq has not been initialized, however it is being incremented
and also not being referenced in a loop.  This error was detected with
cppcheck:

[drivers/misc/cxl/irq.c:439]: (error) Uninitialized variable: hwirq

Commit 80fa93fce3 ("cxl: Name interrupts in /proc/interrupt")
introduced this error.

This is a simple fix that removes the redundant increment.

Signed-off-by: Colin Ian King <colin.king@canonical.com>
Acked-By: Ian Munsie <imunsie@au1.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-01-22 17:31:51 +11:00
Michael Neuling
80fa93fce3 cxl: Name interrupts in /proc/interrupt
Currently all interrupts generated by cxl are named "cxl".  This is not very
informative as we can't distinguish between cards, AFUs, error interrupts, user
contexts and user interrupts numbers.  Being able to distinguish them is useful
for setting affinity.

This patch gives each of these names in /proc/interrupts.

A two card CAPI system, with afu0.0 having 2 active contexts each with 4 user
IRQs each, will now look like this:

    % grep cxl /proc/interrupts
    444:          0  OPAL ICS 141312 Level     cxl-card1-err
    445:          0  OPAL ICS 141313 Level     cxl-afu1.0-err
    446:          0  OPAL ICS 141314 Level     cxl-afu1.0
    462:          0  OPAL ICS 2052 Level     cxl-afu0.0-pe0-1
    463:      75517  OPAL ICS 2053 Level     cxl-afu0.0-pe0-2
    468:          0  OPAL ICS 2054 Level     cxl-afu0.0-pe0-3
    469:          0  OPAL ICS 2055 Level     cxl-afu0.0-pe0-4
    470:          0  OPAL ICS 2056 Level     cxl-afu0.0-pe1-1
    471:      75506  OPAL ICS 2057 Level     cxl-afu0.0-pe1-2
    472:          0  OPAL ICS 2058 Level     cxl-afu0.0-pe1-3
    473:          0  OPAL ICS 2059 Level     cxl-afu0.0-pe1-4
    502:       1066  OPAL ICS 2050 Level     cxl-afu0.0
    514:          0  OPAL ICS 2048 Level     cxl-card0-err
    515:          0  OPAL ICS 2049 Level     cxl-afu0.0-err

Signed-off-by: Michael Neuling <mikey@neuling.org>
Signed-off-by: Ian Munsie <imunsie@au1.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2014-11-18 13:01:39 +11:00
Ian Munsie
bc78b05bb4 cxl: Return error to PSL if IRQ demultiplexing fails & print clearer warning
If an AFU has a hardware bug that causes it to acknowledge a context
terminate or remove while that context has outstanding transactions, it
is possible for the kernel to receive an interrupt for that context
after we have removed it from the context list.

The kernel will not be able to demultiplex the interrupt (or worse - if
we have already reallocated the process handle we could mis-attribute it
to the new context), and printed a big scary warning.

It did not acknowledge the interrupt, which would effectively halt
further translation fault processing on the PSL.

This patch makes the warning clearer about the likely cause of the issue
(i.e. hardware bug) to make it obvious to future AFU designers of what
needs to be fixed. It also prints out the process handle which can then
be matched up with hardware and software traces for debugging.

It also acknowledges the interrupt to the PSL with either an address
error or acknowledge, so that the PSL can continue with other
translations.

Signed-off-by: Ian Munsie <imunsie@au1.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2014-11-18 12:58:38 +11:00
Ian Munsie
f204e0b8ce cxl: Driver code for powernv PCIe based cards for userspace access
This is the core of the cxl driver.

It adds support for using cxl cards in the powernv environment only (ie POWER8
bare metal). It allows access to cxl accelerators by userspace using the
/dev/cxl/afuM.N char devices.

The kernel driver has no knowledge of the function implemented by the
accelerator. It provides services to userspace via the /dev/cxl/afuM.N
devices. When a program opens this device and runs the start work IOCTL, the
accelerator will have coherent access to that processes memory using the same
virtual addresses. That process may mmap the device to access any MMIO space
the accelerator provides.  Also, reads on the device will allow interrupts to
be received. These services are further documented in a later patch in
Documentation/powerpc/cxl.txt.

Documentation of the cxl hardware architecture and userspace API is provided in
subsequent patches.

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