powerpc/pseries/vas: Migration suspend waits for no in-progress open windows

The hypervisor returns migration failure if all VAS windows are not
closed. During pre-migration stage, vas_migration_handler() sets
migration_in_progress flag and closes all windows from the list.
The allocate VAS window routine checks the migration flag, setup
the window and then add it to the list. So there is possibility of
the migration handler missing the window that is still in the
process of setup.

t1: Allocate and open VAS t2: Migration event
window

lock vas_pseries_mutex
If migration_in_progress set
unlock vas_pseries_mutex
return
open window HCALL
unlock vas_pseries_mutex
Modify window HCALL lock vas_pseries_mutex
setup window migration_in_progress=true
Closes all windows from the list
// May miss windows that are
// not in the list
unlock vas_pseries_mutex
lock vas_pseries_mutex return
if nr_closed_windows == 0
// No DLPAR CPU or migration
add window to the list
// Window will be added to the
// list after the setup is completed
unlock vas_pseries_mutex
return
unlock vas_pseries_mutex
Close VAS window
// due to DLPAR CPU or migration
return -EBUSY

This patch resolves the issue with the following steps:
- Set the migration_in_progress flag without holding mutex.
- Introduce nr_open_wins_progress counter in VAS capabilities
struct
- This counter tracks the number of open windows are still in
progress
- The allocate setup window thread closes windows if the migration
is set and decrements nr_open_window_progress counter
- The migration handler waits for no in-progress open windows.

The code flow with the fix is as follows:

t1: Allocate and open VAS t2: Migration event
window

lock vas_pseries_mutex
If migration_in_progress set
unlock vas_pseries_mutex
return
open window HCALL
nr_open_wins_progress++
// Window opened, but not
// added to the list yet
unlock vas_pseries_mutex
Modify window HCALL migration_in_progress=true
setup window lock vas_pseries_mutex
Closes all windows from the list
While nr_open_wins_progress {
unlock vas_pseries_mutex
lock vas_pseries_mutex sleep
if nr_closed_windows == 0 // Wait if any open window in
or migration is not started // progress. The open window
// No DLPAR CPU or migration // thread closes the window without
add window to the list // adding to the list and return if
nr_open_wins_progress-- // the migration is in progress.
unlock vas_pseries_mutex
return
Close VAS window
nr_open_wins_progress--
unlock vas_pseries_mutex
return -EBUSY lock vas_pseries_mutex
}
unlock vas_pseries_mutex
return

Fixes: 37e6764895ef ("powerpc/pseries/vas: Add VAS migration handler")
Signed-off-by: Haren Myneni <haren@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20231125235104.3405008-1-haren@linux.ibm.com

powerpc/vas: Limit open window failure messages in log bufffer

The VAS open window call prints error message and returns -EBUSY
after the migration suspend event initiated and until the resume
event completed on the destination system. It can cause the log
buffer filled with these error messages if the user space issues
continuous open window calls. Similar case even for DLPAR CPU
remove event when no credits are available until the credits are
freed or with the other DLPAR CPU add event.

So changes in the patch to use pr_err_ratelimited() instead of
pr_err() to display open window failure and not-available credits
error messages.

Use pr_fmt() and make the corresponding changes to have the
consistencein prefix all pr_*() messages (vas-api.c).

Fixes: 37e6764895ef ("powerpc/pseries/vas: Add VAS migration handler")
Signed-off-by: Haren Myneni <haren@linux.ibm.com>
[mpe: Use "vas-api" as the prefix to match the file name.]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20231019215033.1335251-1-haren@linux.ibm.com

powerpc/pseries: Move VPHN constants into vphn.h

These don't have any particularly good reason to belong in lppaca.h,
move them into their own header.

Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20230823055317.751786-1-mpe@ellerman.id.au

powerpc/pseries/vas: Hold mmap_mutex after mmap lock during window close

Commit 8ef7b9e1765a ("powerpc/pseries/vas: Close windows with DLPAR
core removal") unmaps the window paste address and issues HCALL to
close window in the hypervisor for migration or DLPAR core removal
events. So holds mmap_mutex and then mmap lock before unmap the
paste address. But if the user space issue mmap paste address at
the same time with the migration event, coproc_mmap() is called
after holding the mmap lock which can trigger deadlock when trying
to acquire mmap_mutex in coproc_mmap().

t1: mmap() call to mmap t2: Migration event
window paste address

do_mmap2() migration_store()
ksys_mmap_pgoff() pseries_migrate_partition()
vm_mmap_pgoff() vas_migration_handler()
Acquire mmap lock reconfig_close_windows()
do_mmap() lock mmap_mutex
mmap_region() Acquire mmap lock
call_mmap() //Wait for mmap lock
coproc_mmap() unmap vma
lock mmap_mutex update window status
//wait for mmap_mutex Release mmap lock
mmap vma unlock mmap_mutex
update window status
unlock mmap_mutex
...
Release mmap lock

Fix this deadlock issue by holding mmap lock first before mmap_mutex
in reconfig_close_windows().

Fixes: 8ef7b9e1765a ("powerpc/pseries/vas: Close windows with DLPAR core removal")
Signed-off-by: Haren Myneni <haren@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20230716100506.7833-1-haren@linux.ibm.com

powerpc/64s: Fix VAS mm use after free

The refcount on mm is dropped before the coprocessor is detached.

Reported-by: Sachin Sant <sachinp@linux.ibm.com>
Fixes: 7bc6f71bdff5f ("powerpc/vas: Define and use common vas_window struct")
Fixes: b22f2d88e435c ("powerpc/pseries/vas: Integrate API with open/close windows")
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Tested-by: Sachin Sant <sachinp@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20230607101024.14559-1-npiggin@gmail.com

powerpc/pseries/vas: Ignore VAS update for DLPAR if copy/paste is not enabled

The hypervisor supports user-mode NX from Power10.

pseries_vas_dlpar_cpu() is called from lparcfg_write() to update VAS
windows for DLPAR event in shared processor mode and the kernel gets
-ENOTSUPP for HCALLs if the user-mode NX is not supported. The current
VAS implementation also supports only with Radix page tables. Whereas in
dedicated processor mode, pseries_vas_notifier() is registered only if
the copy/paste feature is enabled. So instead of displaying HCALL error
messages, update VAS capabilities if the copy/paste feature is
available.

This patch ignores updating VAS capabilities in pseries_vas_dlpar_cpu()
and returns success if the copy/paste feature is not enabled. Then
lparcfg_write() completes the processor DLPAR operations without any
failures.

Fixes: 2147783d6bf0 ("powerpc/pseries: Use lparcfg to reconfig VAS windows for DLPAR CPU")
Cc: stable@vger.kernel.org # v6.1+
Signed-off-by: Haren Myneni <haren@linux.ibm.com>
Reviewed-by: Nathan Lynch <nathanl@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/1d0e727e7dbd9a28627ef08ca9df9c86a50175e2.camel@linux.ibm.com

mm: remove zap_page_range and create zap_vma_pages

zap_page_range was originally designed to unmap pages within an address
range that could span multiple vmas. While working on [1], it was
discovered that all callers of zap_page_range pass a range entirely within
a single vma. In addition, the mmu notification call within zap_page
range does not correctly handle ranges that span multiple vmas. When
crossing a vma boundary, a new mmu_notifier_range_init/end call pair with
the new vma should be made.

Instead of fixing zap_page_range, do the following:
- Create a new routine zap_vma_pages() that will remove all pages within
the passed vma. Most users of zap_page_range pass the entire vma and
can use this new routine.
- For callers of zap_page_range not passing the entire vma, instead call
zap_page_range_single().
- Remove zap_page_range.

[1] https://lore.kernel.org/linux-mm/20221114235507.294320-2-mike.kravetz@oracle.com/
Link: https://lkml.kernel.org/r/20230104002732.232573-1-mike.kravetz@oracle.com
Signed-off-by: Mike Kravetz <mike.kravetz@oracle.com>
Suggested-by: Peter Xu <peterx@redhat.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Peter Xu <peterx@redhat.com>
Acked-by: Heiko Carstens <hca@linux.ibm.com> [s390]
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: Christian Borntraeger <borntraeger@linux.ibm.com>
Cc: Christian Brauner <brauner@kernel.org>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Nadav Amit <nadav.amit@gmail.com>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Rik van Riel <riel@surriel.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

powerpc/pseries: Use lparcfg to reconfig VAS windows for DLPAR CPU

The hypervisor assigns VAS (Virtual Accelerator Switchboard)
windows depends on cores configured in LPAR. The kernel uses
OF reconfig notifier to reconfig VAS windows for DLPAR CPU event.
In the case of shared CPU mode partition, the hypervisor assigns
VAS windows depends on CPU entitled capacity, not based on vcpus.
When the user changes CPU entitled capacity for the partition,
drmgr uses /proc/ppc64/lparcfg interface to notify the kernel.

This patch adds the following changes to update VAS resources
for shared mode:
- Call vas reconfig windows from lparcfg_write()
- Ignore reconfig changes in the VAS notifier

Signed-off-by: Haren Myneni <haren@linux.ibm.com>
[mpe: Rework error handling, report any errors as EIO]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/efa9c16e4a78dda4567a16f13dabfd73cb4674a2.camel@linux.ibm.com

powerpc/pseries/vas: Add VAS IRQ primary handler

irq_default_primary_handler() can be used only with IRQF_ONESHOT
flag, but the flag disables IRQ before executing the thread handler
and enables it after the interrupt is handled. But this IRQ disable
sets the VAS IRQ OFF state in the hypervisor. In case if NX faults
during this window, the hypervisor will not deliver the fault
interrupt to the partition and the user space may wait continuously
for the CSB update. So use VAS specific IRQ handler instead of
calling the default primary handler.

Increment pending_faults counter in IRQ handler and the bottom
thread handler will process all faults based on this counter.
In case if the another interrupt is received while the thread is
running, it will be processed using this counter. The synchronization
of top and bottom handlers will be done with IRQTF_RUNTHREAD flag
and will re-enter to bottom half if this flag is set.

Signed-off-by: Haren Myneni <haren@linux.ibm.com>
Reviewed-by: Frederic Barrat <fbarrat@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/aaad8813b4762a6753cfcd0b605a7574a5192ec7.camel@linux.ibm.com

powerpc/pseries/vas: Pass hw_cpu_id to node associativity HCALL

Generally the hypervisor decides to allocate a window on different
VAS instances. But if user space wishes to allocate on the current VAS
instance where the process is executing, the kernel has to pass
associativity domain IDs to allocate VAS window HCALL.

To determine the associativity domain IDs for the current CPU,
smp_processor_id() is passed to node associativity HCALL which may
return H_P2 (-55) error during DLPAR CPU event. This is because Linux
CPU numbers (smp_processor_id()) are not the same as the hypervisor's
view of CPU numbers.

Fix the issue by passing hard_smp_processor_id() with
VPHN_FLAG_VCPU flag (PAPR 14.11.6.1 H_HOME_NODE_ASSOCIATIVITY).

Fixes: b22f2d88e435 ("powerpc/pseries/vas: Integrate API with open/close windows")
Reviewed-by: Nathan Lynch <nathanl@linux.ibm.com>
Signed-off-by: Haren Myneni <haren@linux.ibm.com>
[mpe: Update change log to mention Linux vs HV CPU numbers]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/55380253ea0c11341824cd4c0fc6bbcfc5752689.camel@linux.ibm.com

powerpc/pseries/vas: Remove the unneeded result variable

Return the value vas_register_coproc_api() directly instead of storing it
in another redundant variable.

Reported-by: Zeal Robot <zealci@zte.com.cn>
Signed-off-by: ye xingchen <ye.xingchen@zte.com.cn>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220825072657.229168-1-ye.xingchen@zte.com.cn

powerpc/pseries/vas: Fix comment typo

The double `the' in line 807 is duplicated, remove one.

Signed-off-by: Jason Wang <wangborong@cdjrlc.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220718075553.70897-1-wangborong@cdjrlc.com

powerpc: Include asm/firmware.h in all users of firmware_has_feature()

Trying to remove asm/ppc_asm.h from all places that don't need it
leads to several failures linked to firmware_has_feature().

To fix it, include asm/firmware.h in all files using
firmware_has_feature()

All users found with:

git grep -L "firmware\.h" ` git grep -l "firmware_has_feature("`

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/11956ec181a034b51a881ac9c059eea72c679a73.1651828453.git.christophe.leroy@csgroup.eu

powerpc: fix typos in comments

Various spelling mistakes in comments.
Detected with the help of Coccinelle.

Signed-off-by: Julia Lawall <Julia.Lawall@inria.fr>
Reviewed-by: Joel Stanley <joel@jms.id.au>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220430185654.5855-1-Julia.Lawall@inria.fr

powerpc/pseries/vas: Use QoS credits from the userspace

The user can change the QoS credits dynamically with the
management console interface which notifies OS with sysfs. After
returning from the OS interface successfully, the management
console updates the hypervisor. Since the VAS capabilities in
the hypervisor is not updated when the OS gets the update,
the kernel is using the old total credits value from the
hypervisor. Fix this issue by using the new QoS credits
from the userspace instead of depending on VAS capabilities
from the hypervisor.

Signed-off-by: Haren Myneni <haren@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/76d156f8af1e03cc09369d68e0bfad0c40031bcc.camel@linux.ibm.com

powerpc/pseries/vas: Add VAS migration handler

Since the VAS windows belong to the VAS hardware resource, the
hypervisor expects the partition to close them on source partition
and reopen them after the partition migrated on the destination
machine.

This handler is called before pseries_suspend() to close these
windows and again invoked after migration. All active windows
for both default and QoS types will be closed and mark them
inactive and reopened after migration with this handler.
During the migration, the user space receives paste instruction
failure if it issues copy/paste on these inactive windows.

The current migration implementation does not freeze the user
space and applications can continue to open VAS windows while
migration is in progress. So when the migration_in_progress flag
is set, VAS open window API returns -EBUSY.

Signed-off-by: Haren Myneni <haren@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/05e45ff4f8babd2490ccb7ae923884f4aa21a7e5.camel@linux.ibm.com

powerpc/pseries/vas: Modify reconfig open/close functions for migration

VAS is a hardware engine stays on the chip. So when the partition
migrates, all VAS windows on the source system have to be closed
and reopen them on the destination after migration.

The kernel has to consider both DLPAR CPU and migration events to
take action on VAS windows. So using VAS_WIN_NO_CRED_CLOSE and
VAS_WIN_MIGRATE_CLOSE status bits and windows will be reopened
after migration only after both status bits are cleared.

This patch make changes to the current reconfig_open/close_windows
functions to support migration:
- Set VAS_WIN_MIGRATE_CLOSE to the window status when closes and
reopen windows with the same status during resume.
- Continue to close all windows even if deallocate HCALL failed
(should not happen) since no way to stop migration with the
current LPM implementation.
- If the DLPAR CPU event happens while migration is in progress,
set VAS_WIN_NO_CRED_CLOSE to the window status. Close window
happens with the first event (migration or DLPAR) and Reopen
window happens only with the last event (migration or DLPAR).

Signed-off-by: Haren Myneni <haren@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/0aad580387cb58379496b4cbbd7c5596e9ea70be.camel@linux.ibm.com

powerpc/pseries/vas: Define global hv_cop_caps struct

The coprocessor capabilities struct is used to get default and
QoS capabilities from the hypervisor during init, DLPAR event and
migration. So instead of allocating this struct for each event,
define global struct and reuse it which allows the migration code
to avoid adding an error path.

Also disable copy/paste feature flag if any capabilities HCALL
is failed.

Signed-off-by: Haren Myneni <haren@linux.ibm.com>
Reviewed-by: Nicholas Piggin <npiggin@gmail.com>
Acked-by: Nathan Lynch <nathanl@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/57da6a270fcb9308cd57be7c88037029343080f7.camel@linux.ibm.com

powerpc/pseries/vas: Add 'update_total_credits' entry for QoS capabilities

pseries supports two types of credits - Default (uses normal priority
FIFO) and Qality of service (QoS uses high priority FIFO). The user
decides the number of QoS credits and sets this value with HMC
interface. The total credits for QoS capabilities can be changed
dynamically with HMC interface which invokes drmgr to communicate
to the kernel.

This patch creats 'update_total_credits' entry for QoS capabilities
so that drmgr command can write the new target QoS credits in sysfs.
Instead of using this value, the kernel gets the new QoS capabilities
from the hypervisor whenever update_total_credits is updated to make
sure sync with the QoS target credits in the hypervisor.

Signed-off-by: Haren Myneni <haren@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/b01ef31a0f964686d00243e7de7f09c73c07e69e.camel@linux.ibm.com

powerpc/pseries/vas: sysfs interface to export capabilities

The hypervisor provides the available VAS GZIP capabilities such
as default or QoS window type and the target available credits in
each type. This patch creates sysfs entries and exports the target,
used and the available credits for each feature.

This interface can be used by the user space to determine the credits
usage or to set the target credits in the case of QoS type (for DLPAR).

/sys/devices/vas/vas0/gzip/default_capabilities (default GZIP capabilities)
nr_total_credits /* Total credits available. Can be
/* changed with DLPAR operation */
nr_used_credits /* Used credits */

/sys/devices/vas/vas0/gzip/qos_capabilities (QoS GZIP capabilities)
nr_total_credits
nr_used_credits

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/702d8b626ebfac2b52f4995eebeafe1c9a6fcb75.camel@linux.ibm.com

powerpc/pseries/vas: Reopen windows with DLPAR core add

VAS windows can be closed in the hypervisor due to lost credits
when the core is removed and the kernel gets fault for NX
requests on these inactive windows. If the NX requests are
issued on these inactive windows, OS gets page faults and the
paste failure will be returned to the user space. If the lost
credits are available later with core add, reopen these windows
and set them active. Later when the OS sees page faults on these
active windows, it creates mapping on the new paste address.
Then the user space can continue to use these windows and send
HW compression requests to NX successfully.

Signed-off-by: Haren Myneni <haren@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/d9f360e21355e6826142c81146acfa9b60bc7ecc.camel@linux.ibm.com

powerpc/pseries/vas: Close windows with DLPAR core removal

The hypervisor assigns vas credits (windows) for each LPAR based
on the number of cores configured in that system. The OS is
expected to release credits when cores are removed, and may
allocate more when cores are added. So there is a possibility of
using excessive credits (windows) in the LPAR and the hypervisor
expects the system to close the excessive windows so that NX load
can be equally distributed across all LPARs in the system.

When the OS closes the excessive windows in the hypervisor,
it sets the window status inactive and invalidates window
virtual address mapping. The user space receives paste instruction
failure if any NX requests are issued on the inactive window.
Then the user space can use with the available open windows or
retry NX requests until this window active again.

This patch also adds the notifier for core removal/add to close
windows in the hypervisor if the system lost credits (core
removal) and reopen windows in the hypervisor when the previously
lost credits are available.

Signed-off-by: Haren Myneni <haren@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/108928f9c00a48cc6a722315d482d07cf66acf5a.camel@linux.ibm.com

powerpc/pseries/vas: Save PID in pseries_vas_window struct

The kernel sets the VAS window with PID when it is opened in
the hypervisor. During DLPAR operation, windows can be closed and
reopened in the hypervisor when the credit is available. So saves
this PID in pseries_vas_window struct when the window is opened
initially and reuse it later during DLPAR operation.

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/a57cbe6d292fe49ad55a0b49c5679d6a24d8fe73.camel@linux.ibm.com

powerpc/pseries/vas: Use common names in VAS capability structure

nr_total/nr_used_credits provides credits usage to user space
via sysfs and the same interface can be used on PowerNV in
future. Changed with proper naming so that applicable on both
pseries and PowerNV.

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/f4313e9f198ee4f8d4fa4d015d8d1873e17851e6.camel@linux.ibm.com

powerpc/pseries: Add __init attribute to eligible functions

Some functions defined in 'arch/powerpc/platforms/pseries' are
deserving of an `__init` macro attribute. These functions are only
called by other initialization functions and therefore should inherit
the attribute.
Also, change function declarations in header files to include `__init`.

Signed-off-by: Nick Child <nick.child@ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20211216220035.605465-13-nick.child@ibm.com

powerpc/pseries/vas: Don't print an error when VAS is unavailable

KVM does not support VAS so guests always print a useless error on boot

vas: HCALL(398) error -2, query_type 0, result buffer 0x57f2000

Change this to only print the message if the error is not H_FUNCTION.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20211126052133.1664375-1-npiggin@gmail.com

powerpc/pseries/vas: Declare pseries_vas_fault_thread_fn() as static

This fixes a compile error with W=1.

Fixes: 6d0aaf5e0de0 ("powerpc/pseries/vas: Setup IRQ and fault handling")
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210819125656.14498-3-clg@kaod.org

powerpc/pseries/vas: Include irqdomain.h

There are patches in flight to break the dependency between asm/irq.h
and linux/irqdomain.h, which would break compilation of vas.c because it
needs the declaration of irq_create_mapping() etc.

So add an explicit include of irqdomain.h to avoid that becoming a
problem in future.

Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210625045337.3197833-1-mpe@ellerman.id.au

powerpc/pseries/vas: Setup IRQ and fault handling

NX generates an interrupt when sees a fault on the user space
buffer and the hypervisor forwards that interrupt to OS. Then
the kernel handles the interrupt by issuing H_GET_NX_FAULT hcall
to retrieve the fault CRB information.

This patch also adds changes to setup and free IRQ per each
window and also handles the fault by updating the CSB.

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/b8fc66dcb783d06a099a303e5cfc69087bb3357a.camel@linux.ibm.com

powerpc/pseries/vas: Integrate API with open/close windows

This patch adds VAS window allocatioa/close with the corresponding
hcalls. Also changes to integrate with the existing user space VAS
API and provide register/unregister functions to NX pseries driver.

The driver register function is used to create the user space
interface (/dev/crypto/nx-gzip) and unregister to remove this entry.

The user space process opens this device node and makes an ioctl
to allocate VAS window. The close interface is used to deallocate
window.

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/e8d956bace3f182c4d2e66e343ff37cb0391d1fd.camel@linux.ibm.com

powerpc/pseries/vas: Implement getting capabilities from hypervisor

The hypervisor provides VAS capabilities for GZIP default and QoS
features. These capabilities gives information for the specific
features such as total number of credits available in LPAR,
maximum credits allowed per window, maximum credits allowed in
LPAR, whether usermode copy/paste is supported, and etc.

This patch adds the following:
- Retrieve all features that are provided by hypervisor using
H_QUERY_VAS_CAPABILITIES hcall with 0 as feature type.
- Retrieve capabilities for the specific feature using the same
hcall and the feature type (1 for QoS and 2 for default type).

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/177c88608cb88f7b87d1c546103f18cec6c056b4.camel@linux.ibm.com

powerpc/pseries/vas: Add hcall wrappers for VAS handling

This patch adds the following hcall wrapper functions to allocate,
modify and deallocate VAS windows, and retrieve VAS capabilities.

H_ALLOCATE_VAS_WINDOW: Allocate VAS window
H_DEALLOCATE_VAS_WINDOW: Close VAS window
H_MODIFY_VAS_WINDOW: Setup window before using
H_QUERY_VAS_CAPABILITIES: Get VAS capabilities

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/40fb02a4d56ca4e240b074a15029082055be5997.camel@linux.ibm.com