During an eeh call to cxl_remove can result in double free_irq of
psl,slice interrupts. This can happen if perst_reloads_same_image == 1
and call to cxl_configure_adapter() fails during slot_reset
callback. In such a case we see a kernel oops with following back-trace:

Oops: Kernel access of bad area, sig: 11 [#1]
Call Trace:
  free_irq+0x88/0xd0 (unreliable)
  cxl_unmap_irq+0x20/0x40 [cxl]
  cxl_native_release_psl_irq+0x78/0xd8 [cxl]
  pci_deconfigure_afu+0xac/0x110 [cxl]
  cxl_remove+0x104/0x210 [cxl]
  pci_device_remove+0x6c/0x110
  device_release_driver_internal+0x204/0x2e0
  pci_stop_bus_device+0xa0/0xd0
  pci_stop_and_remove_bus_device+0x28/0x40
  pci_hp_remove_devices+0xb0/0x150
  pci_hp_remove_devices+0x68/0x150
  eeh_handle_normal_event+0x140/0x580
  eeh_handle_event+0x174/0x360
  eeh_event_handler+0x1e8/0x1f0

This patch fixes the issue of double free_irq by checking that
variables that hold the virqs (err_hwirq, serr_hwirq, psl_virq) are
not '0' before un-mapping and resetting these variables to '0' when
they are un-mapped.

Cc: stable@vger.kernel.org
Signed-off-by: NVaibhav Jain <vaibhav@linux.vnet.ibm.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

In some situations, a faulty AFU slice may create an interrupt storm of
slice errors, rendering the machine unusable. Since these interrupts are
informational only, present the interrupt once, then mask it off to
prevent it from being retriggered until the AFU is reset.
Signed-off-by: NAlastair D'Silva <alastair@d-silva.org>
Reviewed-by: NAndrew Donnellan <andrew.donnellan@au1.ibm.com>
Reviewed-by: NVaibhav Jain <vaibhav@linux.vnet.ibm.com>
Acked-by: NFrederic Barrat <fbarrat@linux.vnet.ibm.com>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>

Fix a boundary condition where in some cases an eeh event that results
in card reset isn't passed on to a driver attached to the virtual PCI
device associated with a slice. This will happen in case when a slice
attached device driver returns a value other than
PCI_ERS_RESULT_NEED_RESET from the eeh error_detected() callback. This
would result in an early return from cxl_pci_error_detected() and
other drivers attached to other AFUs on the card wont be notified.

The patch fixes this by making sure that all slice attached
device-drivers are notified and the return values from
error_detected() callback are aggregated in a scheme where request for
'disconnect' trumps all and 'none' trumps 'need_reset'.

Fixes: 9e8df8a2 ("cxl: EEH support")
Cc: stable@vger.kernel.org # v4.3+
Signed-off-by: NVaibhav Jain <vaibhav@linux.vnet.ibm.com>
Reviewed-by: NAndrew Donnellan <andrew.donnellan@au1.ibm.com>
Acked-by: NFrederic Barrat <fbarrat@linux.vnet.ibm.com>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>

During an eeh event when the cxl card is fenced and card sysfs attr
perst_reloads_same_image is set following warning message is seen in the
kernel logs:

  Adapter context unlocked with 0 active contexts
  ------------[ cut here ]------------
  WARNING: CPU: 12 PID: 627 at
  ../drivers/misc/cxl/main.c:325 cxl_adapter_context_unlock+0x60/0x80 [cxl]

Even though this warning is harmless, it clutters the kernel log
during an eeh event. This warning is triggered as the EEH callback
cxl_pci_error_detected doesn't obtain a context-lock before forcibly
detaching all active context and when context-lock is released during
call to cxl_configure_adapter from cxl_pci_slot_reset, a warning in
cxl_adapter_context_unlock is triggered.

To fix this warning, we acquire the adapter context-lock via
cxl_adapter_context_lock() in the eeh callback
cxl_pci_error_detected() once all the virtual AFU PHBs are notified
and their contexts detached. The context-lock is released in
cxl_pci_slot_reset() after the adapter is successfully reconfigured
and before the we call the slot_reset callback on slice attached
device-drivers.

Fixes: 70b565bb ("cxl: Prevent adapter reset if an active context exists")
Cc: stable@vger.kernel.org # v4.9+
Reported-by: NAndrew Donnellan <andrew.donnellan@au1.ibm.com>
Signed-off-by: NVaibhav Jain <vaibhav@linux.vnet.ibm.com>
Acked-by: NFrederic Barrat <fbarrat@linux.vnet.ibm.com>
Reviewed-by: NMatthew R. Ochs <mrochs@linux.vnet.ibm.com>
Tested-by: NUma Krishnan <ukrishn@linux.vnet.ibm.com>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>

Add support for future IBM Coherent Accelerator (CXL) devices
with an IDs of 0x0623 and 0x0628.
Signed-off-by: NMatthew R. Ochs <mrochs@linux.vnet.ibm.com>
Signed-off-by: NUma Krishnan <ukrishn@linux.vnet.ibm.com>
Acked-by: NFrederic Barrat <fbarrat@linux.vnet.ibm.com>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>

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: NChristophe Lombard <clombard@linux.vnet.ibm.com>
Acked-by: NFrederic Barrat <fbarrat@linux.vnet.ibm.com>
[mpe: Fixup comment formatting, unsplit long strings]
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>

Point out the specific Coherent Accelerator Interface Architecture,
level 1, registers.
Code and functions specific to PSL8 (CAIA1) must be framed.
Signed-off-by: NChristophe Lombard <clombard@linux.vnet.ibm.com>
Acked-by: NFrederic Barrat <fbarrat@linux.vnet.ibm.com>
[mpe: Don't split long strings, it makes them hard to grep for]
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>

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: NChristophe Lombard <clombard@linux.vnet.ibm.com>
Reviewed-by: NAndrew Donnellan <andrew.donnellan@au1.ibm.com>
Acked-by: NFrederic Barrat <fbarrat@linux.vnet.ibm.com>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>

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: NChristophe Lombard <clombard@linux.vnet.ibm.com>
Reviewed-by: NAndrew Donnellan <andrew.donnellan@au1.ibm.com>
Acked-by: NFrederic Barrat <fbarrat@linux.vnet.ibm.com>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>

The mm_struct corresponding to the current task is acquired each time
an interrupt is raised. So to simplify the code, we only get the
mm_struct when attaching an AFU context to the process.
The mm_count reference is increased to ensure that the mm_struct can't
be freed. The mm_struct will be released when the context is detached.
A reference on mm_users is not kept to avoid a circular dependency if
the process mmaps its cxl mmio and forget to unmap before exiting.
The field glpid (pid of the group leader associated with the pid), of
the structure cxl_context, is removed because it's no longer useful.
Signed-off-by: NChristophe Lombard <clombard@linux.vnet.ibm.com>
Reviewed-by: NAndrew Donnellan <andrew.donnellan@au1.ibm.com>
Acked-by: NFrederic Barrat <fbarrat@linux.vnet.ibm.com>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>

The two previously fields pid and tid, located in the structure
cxl_irq_info, are only used in the guest environment. To avoid confusion,
it's not necessary to fill the fields in the bare-metal environment.
Pid_tid is now renamed to 'reserved' to avoid undefined behavior on
bare-metal. The PSL Process and Thread Identification Register
(CXL_PSL_PID_TID_An) is only used when attaching a dedicated process
for PSL8 only. This register goes away in CAIA2.
Signed-off-by: NChristophe Lombard <clombard@linux.vnet.ibm.com>
Reviewed-by: NAndrew Donnellan <andrew.donnellan@au1.ibm.com>
Acked-by: NFrederic Barrat <fbarrat@linux.vnet.ibm.com>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>

This bit is used to cause a flash image load for programmable
CAIA-compliant implementation. If this bit is set to ‘0’, a power
cycle of the adapter is required to load a programmable CAIA-com-
pliant implementation from flash.
This field will be used by the following patches.
Signed-off-by: NChristophe Lombard <clombard@linux.vnet.ibm.com>
Reviewed-by: NAndrew Donnellan <andrew.donnellan@au1.ibm.com>
Acked-by: NFrederic Barrat <fbarrat@linux.vnet.ibm.com>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>

This patch fix some spelling typos found in printk.

[jkosina@suse.cz: drop arch/arm64/kernel/hibernate.c that was already
 in place]
Signed-off-by: NMasanari Iida <standby24x7@gmail.com>
Acked-by: NRandy Dunlap <rdunlap@infradead.org>
Signed-off-by: NJiri Kosina <jkosina@suse.cz>

Fix a boundary condition where in some cases an eeh event with state ==
pci_channel_io_perm_failure wont be passed on to a driver attached to
the virtual PCI device associated with a slice. This will happen in case
the slice just before (n-1) doesn't have any vPHB bus associated with
it, that results in an early return from cxl_pci_error_detected()
callback.

With state == pci_channel_io_perm_failure, the adapter will be removed
irrespective of the return value of cxl_vphb_error_detected(). So we now
always return PCI_ERS_RESULT_DISCONNECTED for this case i.e even if
the AFU isn't using a vPHB (currently returns PCI_ERS_RESULT_NONE).

Fixes: e4f5fc00("cxl: Do not create vPHB if there are no AFU configuration records")
Signed-off-by: NVaibhav Jain <vaibhav@linux.vnet.ibm.com>
Reviewed-by: NMatthew R. Ochs <mrochs@linux.vnet.ibm.com>
Reviewed-by: NAndrew Donnellan <andrew.donnellan@au1.ibm.com>
Acked-by: NFrederic Barrat <fbarrat@linux.vnet.ibm.com>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>

sched/headers: Prepare to move the get_task_struct()/put_task_struct() and related APIs from <linux/sched.h> to <linux/sched/task.h>

But first update usage sites with the new header dependency.
Acked-by: NLinus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: NIngo Molnar <mingo@kernel.org>

sched/headers: Prepare to move signal wakeup & sigpending methods from <linux/sched.h> into <linux/sched/signal.h>

Fix up affected files that include this signal functionality via sched.h.
Acked-by: NLinus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: NIngo Molnar <mingo@kernel.org>

We are going to split <linux/sched/mm.h> out of <linux/sched.h>, which
will have to be picked up from other headers and a couple of .c files.

Create a trivial placeholder <linux/sched/mm.h> file that just
maps to <linux/sched.h> to make this patch obviously correct and
bisectable.

The APIs that are going to be moved first are:

   mm_alloc()
   __mmdrop()
   mmdrop()
   mmdrop_async_fn()
   mmdrop_async()
   mmget_not_zero()
   mmput()
   mmput_async()
   get_task_mm()
   mm_access()
   mm_release()

Include the new header in the files that are going to need it.
Acked-by: NLinus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: NIngo Molnar <mingo@kernel.org>

We are going to split <linux/sched/clock.h> out of <linux/sched.h>, which
will have to be picked up from other headers and .c files.

Create a trivial placeholder <linux/sched/clock.h> file that just
maps to <linux/sched.h> to make this patch obviously correct and
bisectable.

Include the new header in the files that are going to need it.
Acked-by: NLinus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: NIngo Molnar <mingo@kernel.org>

->fault(), ->page_mkwrite(), and ->pfn_mkwrite() calls do not need to
take a vma and vmf parameter when the vma already resides in vmf.

Remove the vma parameter to simplify things.

[arnd@arndb.de: fix ARM build]
  Link: http://lkml.kernel.org/r/20170125223558.1451224-1-arnd@arndb.de
Link: http://lkml.kernel.org/r/148521301778.19116.10840599906674778980.stgit@djiang5-desk3.ch.intel.comSigned-off-by: NDave Jiang <dave.jiang@intel.com>
Signed-off-by: NArnd Bergmann <arnd@arndb.de>
Reviewed-by: NRoss Zwisler <ross.zwisler@linux.intel.com>
Cc: Theodore Ts'o <tytso@mit.edu>
Cc: Darrick J. Wong <darrick.wong@oracle.com>
Cc: Matthew Wilcox <mawilcox@microsoft.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Jan Kara <jack@suse.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Commit 14a3ae34 ("cxl: Prevent read/write to AFU config space while AFU
not configured") introduced a rwsem to fix an invalid memory access that
occurred when someone attempts to access the config space of an AFU on a
vPHB whilst the AFU is deconfigured, such as during EEH recovery.

It turns out that it's possible to run into a nested locking issue when EEH
recovery fails and a full device hotplug is required.
cxl_pci_error_detected() deconfigures the AFU, taking a writer lock on
configured_rwsem. When EEH recovery fails, the EEH code calls
pci_hp_remove_devices() to remove the device, which in turn calls
cxl_remove() -> cxl_pci_remove_afu() -> pci_deconfigure_afu(), which tries
to grab the writer lock that's already held.

Standard rwsem semantics don't express what we really want to do here and
don't allow for nested locking. Fix this by replacing the rwsem with an
atomic_t which we can control more finely. Allow the AFU to be locked
multiple times so long as there are no readers.

Fixes: 14a3ae34 ("cxl: Prevent read/write to AFU config space while AFU not configured")
Cc: stable@vger.kernel.org # v4.9+
Signed-off-by: NAndrew Donnellan <andrew.donnellan@au1.ibm.com>
Acked-by: NFrederic Barrat <fbarrat@linux.vnet.ibm.com>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>

Stub out the debugfs functions so that the build doesn't break when
CONFIG_DEBUG_FS=n.
Reported-by: NMichael Ellerman <mpe@ellerman.id.au>
Signed-off-by: NAndrew Donnellan <andrew.donnellan@au1.ibm.com>
Acked-by: NIan Munsie <imunsie@au1.ibm.com>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>

During EEH recovery, we deconfigure all AFUs whilst leaving the
corresponding vPHB and virtual PCI device in place.

If something attempts to interact with the AFU's PCI config space (e.g.
running lspci) after the AFU has been deconfigured and before it's
reconfigured, cxl_pcie_{read,write}_config() will read invalid values from
the deconfigured struct cxl_afu and proceed to Oops when they try to
dereference pointers that have been set to NULL during deconfiguration.

Add a rwsem to struct cxl_afu so we can prevent interaction with config
space while the AFU is deconfigured.
Reported-by: NPradipta Ghosh <pradghos@in.ibm.com>
Suggested-by: NFrederic Barrat <fbarrat@linux.vnet.ibm.com>
Cc: stable@vger.kernel.org # v4.9+
Signed-off-by: NAndrew Donnellan <andrew.donnellan@au1.ibm.com>
Signed-off-by: NVaibhav Jain <vaibhav@linux.vnet.ibm.com>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>

This change adds a force psl data cache flush during device shutdown
callback. This should reduce a possibility of psl holding a dirty
cache line while the CAPP is being reinitialized, which may result in
a UE [load/store] machine check error.
Signed-off-by: NVaibhav Jain <vaibhav@linux.vnet.ibm.com>
Reviewed-by: NAndrew Donnellan <andrew.donnellan@au1.ibm.com>
Acked-by: NFrederic Barrat <fbarrat@linux.vnet.ibm.com>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>

The kernel API does not use anything from this header file.
Signed-off-by: NGreg Kurz <groug@kaod.org>
Reviewed-by: NAndrew Donnellan <andrew.donnellan@au1.ibm.com>
Acked-by: NFrederic Barrat <fbarrat@linux.vnet.ibm.com>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>

Every single user of vmf->virtual_address typed that entry to unsigned
long before doing anything with it so the type of virtual_address does
not really provide us any additional safety.  Just use masked
vmf->address which already has the appropriate type.

Link: http://lkml.kernel.org/r/1479460644-25076-3-git-send-email-jack@suse.czSigned-off-by: NJan Kara <jack@suse.cz>
Acked-by: NKirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Ross Zwisler <ross.zwisler@linux.intel.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Drop duplicate header sched.h from native.c.
Signed-off-by: NGeliang Tang <geliangtang@gmail.com>
Reviewed-by: NAndrew Donnellan <andrew.donnellan@au1.ibm.com>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>

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: NAndrew Donnellan <andrew.donnellan@au1.ibm.com>
Acked-by: NFrederic Barrat <fbarrat@linux.vnet.ibm.com>
Reviewed-by: NMatthew R. Ochs <mrochs@linux.vnet.ibm.com>
Acked-by: NIan Munsie <imunsie@au1.ibm.com>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>

If a process dumps core while owning a cxl file descriptor obtained
from an AFU driver (e.g. cxlflash) through the cxl_get_fd() API, the
following error occurs:

  [  868.027591] Unable to handle kernel paging request for data at address ...
  [  868.027778] Faulting instruction address: 0xc00000000035edb0
  cpu 0x8c: Vector: 300 (Data Access) at [c000003c688275e0]
      pc: c00000000035edb0: elf_core_dump+0xd60/0x1300
      lr: c00000000035ed80: elf_core_dump+0xd30/0x1300
      sp: c000003c68827860
     msr: 9000000100009033
     dar: c
  dsisr: 40000000
   current = 0xc000003c68780000
   paca    = 0xc000000001b73200   softe: 0        irq_happened: 0x01
      pid   = 46725, comm = hxesurelock
  enter ? for help
  [c000003c68827a60] c00000000036948c do_coredump+0xcec/0x11e0
  [c000003c68827c20] c0000000000ce9e0 get_signal+0x540/0x7b0
  [c000003c68827d10] c000000000017354 do_signal+0x54/0x2b0
  [c000003c68827e00] c00000000001777c do_notify_resume+0xbc/0xd0
  [c000003c68827e30] c000000000009838 ret_from_except_lite+0x64/0x68
  --- Exception: 300 (Data Access) at 00003fff98ad2918

The root cause is that the address_space structure for the file
doesn't define a 'host' member.

When cxl allocates a file descriptor, it's using the anonymous inode
to back the file, but allocates a private address_space for each
context. The private address_space allows to track memory allocation
for each context. cxl doesn't define the 'host' member of the address
space, i.e. the inode. We don't want to define it as the anonymous
inode, since there's no longer a 1-to-1 relation between address_space
and inode.

To fix it, instead of using the anonymous inode, we introduce a simple
pseudo filesystem so that cxl can allocate its own inodes. So we now
have one inode for each file and address_space. The pseudo filesystem
is only mounted on the first allocation of a file descriptor by
cxl_get_fd().

Tested with cxlflash.
Signed-off-by: NFrederic Barrat <fbarrat@linux.vnet.ibm.com>
Reviewed-by: NMatthew R. Ochs <mrochs@linux.vnet.ibm.com>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>

If an afu interrupt is in flight when an eeh error is triggered the
control still reaches the function native_irq_multiplexed and the
PE-Handle read from the CXL_PSL_PEHandle_An register is 0xffff. The
function then erroneously assumes that the interrupt belonged to a
detached context and generates a warning with full stack dump in the
kernel log complaining:

"Unable to demultiplex CXL PSL IRQ for PE 65535 DSISR ffffffff DAR
ffffffff. (Possible AFU HW issue - was a term/remove acked with
outstanding transactions"

To fix this the patch adds new code to the function
native_irq_multiplexed function to compares the read value of register
CXL_PSL_PEHandle_An to ~0ULL. If true then logs a warning message
saying that the interrupt is being ignored and returns IRQ_HANDLED from
the irq handler.
Reviewed-by: NAndrew Donnellan <andrew.donnellan@au1.ibm.com>
Acked-by: NFrederic Barrat <fbarrat@linux.vnet.ibm.com>
Acked-by: NIan Munsie <imunsie@au1.ibm.com>
Signed-off-by: NVaibhav Jain <vaibhav@linux.vnet.ibm.com>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>

'cxl_dev_context_init()' returns an error pointer in case of error, not
NULL. So test it with IS_ERR.
Signed-off-by: NChristophe JAILLET <christophe.jaillet@wanadoo.fr>
Reviewed-by: NAndrew Donnellan <andrew.donnellan@au1.ibm.com>
Acked-by: NFrederic Barrat <fbarrat@linux.vnet.ibm.com>
Acked-by: NIan Munsie <imunsie@au1.ibm.com>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>

'cxl_dev_context_init()' returns an error pointer in case of error, not
NULL. So test it with IS_ERR.
Signed-off-by: NChristophe JAILLET <christophe.jaillet@wanadoo.fr>
Reviewed-by: NAndrew Donnellan <andrew.donnellan@au1.ibm.com>
Acked-by: NFrederic Barrat <fbarrat@linux.vnet.ibm.com>
Acked-by: NIan Munsie <imunsie@au1.ibm.com>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>

'cxl_context_alloc()' does not return an error pointer. It is just a
shortcut for a call to 'kzalloc' with 'sizeof(struct cxl_context)' as the
size parameter.

So its return value should be compared with NULL.
While fixing it, simplify a bit the code.
Signed-off-by: NChristophe JAILLET <christophe.jaillet@wanadoo.fr>
Reviewed-by: NAndrew Donnellan <andrew.donnellan@au1.ibm.com>
Acked-by: NFrederic Barrat <fbarrat@linux.vnet.ibm.com>
Acked-by: NIan Munsie <imunsie@au1.ibm.com>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>

In some error paths in functions cxl_start_context and
afu_ioctl_start_work pid references to the current & group-leader tasks
can leak after they are taken. This patch fixes these error paths to
release these pid references before exiting the error path.

Fixes: 7b8ad495 ("cxl: Fix DSI misses when the context owning task exits")
Cc: stable@vger.kernel.org # v4.5+
Reviewed-by: NAndrew Donnellan <andrew.donnellan@au1.ibm.com>
Reported-by: NFrederic Barrat <fbarrat@linux.vnet.ibm.com>
Signed-off-by: NVaibhav Jain <vaibhav@linux.vnet.ibm.com>
Acked-by: NFrederic Barrat <fbarrat@linux.vnet.ibm.com>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>

This patch prevents resetting the cxl adapter via sysfs in presence of
one or more active cxl_context on it. This protects against an
unrecoverable error caused by PSL owning a dirty cache line even after
reset and host tries to touch the same cache line. In case a force reset
of the card is required irrespective of any active contexts, the int
value -1 can be stored in the 'reset' sysfs attribute of the card.

The patch introduces a new atomic_t member named contexts_num inside
struct cxl that holds the number of active context attached to the card
, which is checked against '0' before proceeding with the reset. To
prevent against a race condition where a context is activated just after
reset check is performed, the contexts_num is atomically set to '-1'
after reset-check to indicate that no more contexts can be activated on
the card anymore.

Before activating a context we atomically test if contexts_num is
non-negative and if so, increment its value by one. In case the value of
contexts_num is negative then it indicates that the card is about to be
reset and context activation is error-ed out at that point.

Fixes: 62fa19d4 ("cxl: Add ability to reset the card")
Cc: stable@vger.kernel.org # v4.0+
Acked-by: NFrederic Barrat <fbarrat@linux.vnet.ibm.com>
Reviewed-by: NAndrew Donnellan <andrew.donnellan@au1.ibm.com>
Signed-off-by: NVaibhav Jain <vaibhav@linux.vnet.ibm.com>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>

Rewrite the cxl_guest_init_afu() loop in cxl_of_probe() to use
for_each_child_of_node() rather than a hand-coded for loop.

Remove the useless of_node_put(afu_np) call after the loop, where it's
guaranteed that afu_np == NULL.
Reported-by: NSF Markus Elfring <elfring@users.sourceforge.net>
Reported-by: NJulia Lawall <julia.lawall@lip6.fr>
Signed-off-by: NAndrew Donnellan <andrew.donnellan@au1.ibm.com>
Reviewed-by: NFrederic Barrat <fbarrat@linux.vnet.ibm.com>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>

If the capi link is going down while the PSL owns a dirty cache line,
any access from the host for that data could lead to an Uncorrectable
Error.

So when resetting the capi adapter through sysfs, make sure the PSL
cache is flushed. It won't help if there are any active Process
Elements on the card, as the cache would likely get new dirty cache
lines immediately, but if resetting an idle adapter, it should avoid
any bad surprises from data left over from terminated Process Elements.
Signed-off-by: NFrederic Barrat <fbarrat@linux.vnet.ibm.com>
Reviewed-by: NAndrew Donnellan <andrew.donnellan@au1.ibm.com>
Acked-by: NIan Munsie <imunsie@au1.ibm.com>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>

When set_sl_ops() is called, the adapter data structure is not fully
initialized yet. Therefore the device name is not showing up in the
trace. Fix is simply to get the device name from the pci_dev
structure.

Fixes: 6d382616 ("cxl: Abstract the differences between the PSL and XSL")
Signed-off-by: NFrederic Barrat <fbarrat@linux.vnet.ibm.com>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>

When cxl removes a vPHB, it's possible that the pci_controller may be freed
before all references to the devices on the vPHB have been released. This
in turn causes an invalid memory access when the devices are eventually
released, as pcibios_release_device() attempts to call the phb's
release_device hook.

In cxl_pci_vphb_remove(), remove the existing call to
pcibios_free_controller(). Instead, use
pcibios_free_controller_deferred() to free the pci_controller after all
devices have been released. Export pci_set_host_bridge_release() so we can
do this.

Cc: stable@vger.kernel.org
Signed-off-by: NAndrew Donnellan <andrew.donnellan@au1.ibm.com>
Reviewed-by: NMatthew R. Ochs <mrochs@linux.vnet.ibm.com>
Acked-by: NIan Munsie <imunsie@au1.ibm.com>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

Switch the setting of psl_fir_cntl from debug to production
environment recommended value. It mostly affects the PSL behavior when
an error is raised in psl_fir1/2.

Tested with cxlflash.
Signed-off-by: NFrederic Barrat <fbarrat@linux.vnet.ibm.com>
Reviewed-by: NUma Krishnan <ukrishn@linux.vnet.ibm.com>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>

Make native_irq_wait() static and use NULL rather than 0 to initialise
phb->cfg_data in cxl_pci_vphb_add() to remove sparse warnings.
Signed-off-by: NAndrew Donnellan <andrew.donnellan@au1.ibm.com>
Reviewed-by: NMatthew R. Ochs <mrochs@linux.vnet.ibm.com>
Acked-by: NIan Munsie <imunsie@au1.ibm.com>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>