These are only called from within qe_ic.c, so make them static.
Reviewed-by: Timur Tabi <timur@kernel.org>
Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Signed-off-by: Li Yang <leoyang.li@nxp.com>

This driver is currently PPC-only, and on powerpc, NO_IRQ is 0, so
this doesn't change functionality. However, not every architecture
defines NO_IRQ, and some define it as -1, so the detection of a failed
irq_of_parse_and_map() (which returns 0 on failure) would be wrong on
those. So to prepare for allowing this driver to build on other
architectures, drop all references to NO_IRQ.
Reviewed-by: Timur Tabi <timur@kernel.org>
Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Signed-off-by: Li Yang <leoyang.li@nxp.com>

There are no current callers of these functions, and they use the
ppc-specific virq_to_hw(). So removing them gets us one step closer to
building QE support for ARM.

If the functionality is ever actually needed, the code can be dug out
of git and then adapted to work on all architectures, but for future
reference please note that I believe qe_ic_set_priority is buggy: The
"priority < 4" should be "priority <= 4", and in the else branch 24
should be replaced by 28, at least if I'm reading the data sheet right.
Reviewed-by: Timur Tabi <timur@kernel.org>
Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Signed-off-by: Li Yang <leoyang.li@nxp.com>

The qe_ic_cascade_{low,high}_mpic functions are now used as handlers
both when the interrupt parent is mpic as well as ipic, so remove the
_mpic suffix.
Reviewed-by: Timur Tabi <timur@kernel.org>
Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Signed-off-by: Li Yang <leoyang.li@nxp.com>

These functions are only ever called through a function pointer, and
therefore it makes no sense for them to be "static inline" - gcc has
no choice but to emit a copy in each translation unit that takes the
address of one of these. Since they are now only referenced from
qe_ic.c, just make them local to that file.
Reviewed-by: Timur Tabi <timur@kernel.org>
Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Signed-off-by: Li Yang <leoyang.li@nxp.com>

This is now exactly the same as mpc83xx_ipic_init_IRQ, so just use
that directly.
Acked-by: Scott Wood <oss@buserror.net>
Reviewed-by: Timur Tabi <timur@kernel.org>
Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Signed-off-by: Li Yang <leoyang.li@nxp.com>

Having to call qe_ic_init() from platform-specific code makes it
awkward to allow building the QE drivers for ARM. It's also a needless
duplication of code, and slightly error-prone: Instead of the caller
needing to know the details of whether the QUICC Engine High and QUICC
Engine Low are actually the same interrupt (see e.g. the machine_is()
in mpc85xx_mds_qeic_init), just let the init function choose the
appropriate handlers after it has parsed the DT and figured it out. If
the two interrupts are distinct, use separate handlers, otherwise use
the handler which first checks the CHIVEC register (for the high
priority interrupts), then the CIVEC.

All existing callers pass 0 for flags, so continue to do that from the
new single caller. Later cleanups will remove that argument
from qe_ic_init and simplify the body, as well as make qe_ic_init into
a proper init function for an IRQCHIP_DECLARE, eliminating the need to
manually look up the fsl,qe-ic node.
Reviewed-by: Timur Tabi <timur@kernel.org>
Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Signed-off-by: Li Yang <leoyang.li@nxp.com>

The *_ipic and *_mpic handlers are almost identical - the only
difference is that the latter end with an unconditional
chip->irq_eoi() call. Since IPIC does not have ->irq_eoi, we can
reduce some code duplication by calling irq_eoi conditionally.

This is similar to what is already done in mpc8xxx_gpio_irq_cascade().

This leaves the functions slightly misnamed, but that will be fixed in
a subsequent patch.
Reviewed-by: Timur Tabi <timur@kernel.org>
Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Signed-off-by: Li Yang <leoyang.li@nxp.com>

There's no point in registering with sysfs when that doesn't actually
allow any interaction with the device or driver (no uevents, no sysfs
files that provide information or allow configuration, no nothing).
Reviewed-by: Timur Tabi <timur@kernel.org>
Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Signed-off-by: Li Yang <leoyang.li@nxp.com>

high_active is only assigned to but never used. Remove it.
Reviewed-by: Timur Tabi <timur@kernel.org>
Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Signed-off-by: Li Yang <leoyang.li@nxp.com>

These includes are not actually needed, and asm/rheap.h and
sysdev/fsl_soc.h are PPC-specific, hence prevent compiling QE for
other architectures.
Reviewed-by: Timur Tabi <timur@kernel.org>
Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Signed-off-by: Li Yang <leoyang.li@nxp.com>

Commit e5c5c8d2 (soc/fsl/qe: only apply QE_General4 workaround on
affected SoCs) introduced use of pvr_version_is(), saying

    The QE_General4 workaround is only valid for the MPC832x and MPC836x
    SoCs. The other SoCs that embed a QUICC engine are not affected by this
    hardware bug and thus can use the computed divisors (this was
    successfully tested on the T1040).

I'm reading the above as saying that the errata does not apply to the
ARM-based SOCs with QUICC engine. In any case, use of pvr_version_is()
must be guarded by CONFIG_PPC32 before we can remove the PPC32
dependency from CONFIG_QUICC_ENGINE, so introduce qe_general4_errata()
to keep the necessary #ifdeffery localized to a trivial helper.
Reviewed-by: Timur Tabi <timur@kernel.org>
Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Signed-off-by: Li Yang <leoyang.li@nxp.com>

In preparation for allowing QE to be built for architectures other
than ppc, use the generic readx_poll_timeout_atomic() helper from
iopoll.h rather than the ppc-only spin_event_timeout().
Reviewed-by: Timur Tabi <timur@kernel.org>
Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Signed-off-by: Li Yang <leoyang.li@nxp.com>

In preparation for allowing to build QE support for architectures
other than PPC, replace the ppc-specific io accessors by the qe_io*
macros. Done via

$ spatch --sp-file io.cocci --in-place drivers/soc/fsl/qe/

where io.cocci is

@@
expression addr, val;
@@
- out_be32(addr, val)
+ qe_iowrite32be(val, addr)

@@
expression addr;
@@
- in_be32(addr)
+ qe_ioread32be(addr)

@@
expression addr, val;
@@
- out_be16(addr, val)
+ qe_iowrite16be(val, addr)

@@
expression addr;
@@
- in_be16(addr)
+ qe_ioread16be(addr)

@@
expression addr, val;
@@
- out_8(addr, val)
+ qe_iowrite8(val, addr)

@@
expression addr;
@@
- in_8(addr)
+ qe_ioread8(addr)

@@
expression addr, clr, set;
@@
- clrsetbits_be32(addr, clr, set)
+ qe_clrsetbits_be32(addr, clr, set)

@@
expression addr, clr, set;
@@
- clrsetbits_be16(addr, clr, set)
+ qe_clrsetbits_be16(addr, clr, set)

@@
expression addr, clr, set;
@@
- clrsetbits_8(addr, clr, set)
+ qe_clrsetbits_8(addr, clr, set)

@@
expression addr, set;
@@
- setbits32(addr, set)
+ qe_setbits_be32(addr, set)

@@
expression addr, set;
@@
- setbits16(addr, set)
+ qe_setbits_be16(addr, set)

@@
expression addr, set;
@@
- setbits8(addr, set)
+ qe_setbits_8(addr, set)

@@
expression addr, clr;
@@
- clrbits32(addr, clr)
+ qe_clrbits_be32(addr, clr)

@@
expression addr, clr;
@@
- clrbits16(addr, clr)
+ qe_clrbits_be16(addr, clr)

@@
expression addr, clr;
@@
- clrbits8(addr, clr)
+ qe_clrbits_8(addr, clr)
Reviewed-by: Timur Tabi <timur@kernel.org>
Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Signed-off-by: Li Yang <leoyang.li@nxp.com>

The QUICC engine drivers use the powerpc-specific out_be32() etc. In
order to allow those drivers to build for other architectures, those
must be replaced by iowrite32be(). However, on powerpc, out_be32() is
a simple inline function while iowrite32be() is out-of-line. So in
order not to introduce a performance regression on powerpc when making
the drivers work on other architectures, introduce qe_io* helpers.

Also define the qe_{clr,set,clrset}bits* helpers in terms of these new
macros.
Reviewed-by: Timur Tabi <timur@kernel.org>
Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Signed-off-by: Li Yang <leoyang.li@nxp.com>

Make it clear that these operate on big-endian registers (i.e. use the
iowrite*be primitives) before we introduce more uses of them and allow
the QE drivers to be built for platforms other than ppc32.
Reviewed-by: Timur Tabi <timur@kernel.org>
Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Signed-off-by: Li Yang <leoyang.li@nxp.com>

The actual io accessors (e.g. in_be32) implicitly add a volatile
qualifier to their address argument. Remove volatile from the struct
definition and the qe_ic_(read/write) helpers, in preparation for
switching from the ppc-specific io accessors to generic ones.
Reviewed-by: Timur Tabi <timur@kernel.org>
Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Signed-off-by: Li Yang <leoyang.li@nxp.com>

Reviewed-by: Timur Tabi <timur@kernel.org>
Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Signed-off-by: Li Yang <leoyang.li@nxp.com>

Pull networking fixes from David Miller:

 1) More jumbo frame fixes in r8169, from Heiner Kallweit.

 2) Fix bpf build in minimal configuration, from Alexei Starovoitov.

 3) Use after free in slcan driver, from Jouni Hogander.

 4) Flower classifier port ranges don't work properly in the HW offload
    case, from Yoshiki Komachi.

 5) Use after free in hns3_nic_maybe_stop_tx(), from Yunsheng Lin.

 6) Out of bounds access in mqprio_dump(), from Vladyslav Tarasiuk.

 7) Fix flow dissection in dsa TX path, from Alexander Lobakin.

 8) Stale syncookie timestampe fixes from Guillaume Nault.

[ Did an evil merge to silence a warning introduced by this pull - Linus ]

* git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (84 commits)
  r8169: fix rtl_hw_jumbo_disable for RTL8168evl
  net_sched: validate TCA_KIND attribute in tc_chain_tmplt_add()
  r8169: add missing RX enabling for WoL on RTL8125
  vhost/vsock: accept only packets with the right dst_cid
  net: phy: dp83867: fix hfs boot in rgmii mode
  net: ethernet: ti: cpsw: fix extra rx interrupt
  inet: protect against too small mtu values.
  gre: refetch erspan header from skb->data after pskb_may_pull()
  pppoe: remove redundant BUG_ON() check in pppoe_pernet
  tcp: Protect accesses to .ts_recent_stamp with {READ,WRITE}_ONCE()
  tcp: tighten acceptance of ACKs not matching a child socket
  tcp: fix rejected syncookies due to stale timestamps
  lpc_eth: kernel BUG on remove
  tcp: md5: fix potential overestimation of TCP option space
  net: sched: allow indirect blocks to bind to clsact in TC
  net: core: rename indirect block ingress cb function
  net-sysfs: Call dev_hold always in netdev_queue_add_kobject
  net: dsa: fix flow dissection on Tx path
  net/tls: Fix return values to avoid ENOTSUPP
  net: avoid an indirect call in ____sys_recvmsg()
  ...

Pull more SCSI updates from James Bottomley:
 "Eleven patches, all in drivers (no core changes) that are either minor
  cleanups or small fixes.

  They were late arriving, but still safe for -rc1"

* tag 'scsi-misc' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi:
  scsi: MAINTAINERS: Add the linux-scsi mailing list to the ISCSI entry
  scsi: megaraid_sas: Make poll_aen_lock static
  scsi: sd_zbc: Improve report zones error printout
  scsi: qla2xxx: Fix qla2x00_request_irqs() for MSI
  scsi: qla2xxx: unregister ports after GPN_FT failure
  scsi: qla2xxx: fix rports not being mark as lost in sync fabric scan
  scsi: pm80xx: Remove unused include of linux/version.h
  scsi: pm80xx: fix logic to break out of loop when register value is 2 or 3
  scsi: scsi_transport_sas: Fix memory leak when removing devices
  scsi: lpfc: size cpu map by last cpu id set
  scsi: ibmvscsi_tgt: Remove unneeded variable rc

Pull cifs fixes from Steve French:
 "Nine cifs/smb3 fixes:

   - one fix for stable (oops during oplock break)

   - two timestamp fixes including important one for updating mtime at
     close to avoid stale metadata caching issue on dirty files (also
     improves perf by using SMB2_CLOSE_FLAG_POSTQUERY_ATTRIB over the
     wire)

   - two fixes for "modefromsid" mount option for file create (now
     allows mode bits to be set more atomically and accurately on create
     by adding "sd_context" on create when modefromsid specified on
     mount)

   - two fixes for multichannel found in testing this week against
     different servers

   - two small cleanup patches"

* tag '5.5-rc-smb3-fixes-part2' of git://git.samba.org/sfrench/cifs-2.6:
  smb3: improve check for when we send the security descriptor context on create
  smb3: fix mode passed in on create for modetosid mount option
  cifs: fix possible uninitialized access and race on iface_list
  cifs: Fix lookup of SMB connections on multichannel
  smb3: query attributes on file close
  smb3: remove unused flag passed into close functions
  cifs: remove redundant assignment to pointer pneg_ctxt
  fs: cifs: Fix atime update check vs mtime
  CIFS: Fix NULL-pointer dereference in smb2_push_mandatory_locks

Pull misc vfs cleanups from Al Viro:
 "No common topic, just three cleanups".

* 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  make __d_alloc() static
  fs/namespace: add __user to open_tree and move_mount syscalls
  fs/fnctl: fix missing __user in fcntl_rw_hint()

Pull NTB update from Jon Mason:
 "Just a simple patch to add a new Hygon Device ID to the AMD NTB device
  driver"

* tag 'ntb-5.5' of git://github.com/jonmason/ntb:
  NTB: Add Hygon Device ID

Pull more input updates from Dmitry Torokhov:

 - fixups for Synaptics RMI4 driver

 - a quirk for Goodinx touchscreen on Teclast tablet

 - a new keycode definition for activating privacy screen feature found
   on a few "enterprise" laptops

 - updates to snvs_pwrkey driver

 - polling uinput device for writing (which is always allowed) now works

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input:
  Input: synaptics-rmi4 - don't increment rmiaddr for SMBus transfers
  Input: synaptics-rmi4 - re-enable IRQs in f34v7_do_reflash
  Input: goodix - add upside-down quirk for Teclast X89 tablet
  Input: add privacy screen toggle keycode
  Input: uinput - fix returning EPOLLOUT from uinput_poll
  Input: snvs_pwrkey - remove gratuitous NULL initializers
  Input: snvs_pwrkey - send key events for i.MX6 S, DL and Q

Pull iomap fixes from Darrick Wong:
 "Fix a race condition and a use-after-free error:

   - Fix a UAF when reporting writeback errors

   - Fix a race condition when handling page uptodate on fragmented file
     with blocksize < pagesize"

* tag 'iomap-5.5-merge-14' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux:
  iomap: stop using ioend after it's been freed in iomap_finish_ioend()
  iomap: fix sub-page uptodate handling

Pull xfs fixes from Darrick Wong:
 "Fix a couple of resource management errors and a hang:

   - fix a crash in the log setup code when log mounting fails

   - fix a hang when allocating space on the realtime device

   - fix a block leak when freeing space on the realtime device"

* tag 'xfs-5.5-merge-17' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux:
  xfs: fix mount failure crash on invalid iclog memory access
  xfs: don't check for AG deadlock for realtime files in bunmapi
  xfs: fix realtime file data space leak

Pull orangefs update from Mike Marshall:
 "orangefs: posix open permission checking...

  Orangefs has no open, and orangefs checks file permissions on each
  file access. Posix requires that file permissions be checked on open
  and nowhere else. Orangefs-through-the-kernel needs to seem posix
  compliant.

  The VFS opens files, even if the filesystem provides no method. We can
  see if a file was successfully opened for read and or for write by
  looking at file->f_mode.

  When writes are flowing from the page cache, file is no longer
  available. We can trust the VFS to have checked file->f_mode before
  writing to the page cache.

  The mode of a file might change between when it is opened and IO
  commences, or it might be created with an arbitrary mode.

  We'll make sure we don't hit EACCES during the IO stage by using
  UID 0"

[ This is "posixish", but not a great solution in the long run, since a
  proper secure network server shouldn't really trust the client like this.
  But proper and secure POSIX behavior requires an open method and a
  resulting cookie for IO of some kind, or similar.    - Linus ]

* tag 'for-linus-5.5-ofs1' of git://git.kernel.org/pub/scm/linux/kernel/git/hubcap/linux:
  orangefs: posix open permission checking...

Pull nfsd updates from Bruce Fields:
 "This is a relatively quiet cycle for nfsd, mainly various bugfixes.

  Possibly most interesting is Trond's fixes for some callback races
  that were due to my incomplete understanding of rpc client shutdown.
  Unfortunately at the last minute I've started noticing a new
  intermittent failure to send callbacks. As the logic seems basically
  correct, I'm leaving Trond's patches in for now, and hope to find a
  fix in the next week so I don't have to revert those patches"

* tag 'nfsd-5.5' of git://linux-nfs.org/~bfields/linux: (24 commits)
  nfsd: depend on CRYPTO_MD5 for legacy client tracking
  NFSD fixing possible null pointer derefering in copy offload
  nfsd: check for EBUSY from vfs_rmdir/vfs_unink.
  nfsd: Ensure CLONE persists data and metadata changes to the target file
  SUNRPC: Fix backchannel latency metrics
  nfsd: restore NFSv3 ACL support
  nfsd: v4 support requires CRYPTO_SHA256
  nfsd: Fix cld_net->cn_tfm initialization
  lockd: remove __KERNEL__ ifdefs
  sunrpc: remove __KERNEL__ ifdefs
  race in exportfs_decode_fh()
  nfsd: Drop LIST_HEAD where the variable it declares is never used.
  nfsd: document callback_wq serialization of callback code
  nfsd: mark cb path down on unknown errors
  nfsd: Fix races between nfsd4_cb_release() and nfsd4_shutdown_callback()
  nfsd: minor 4.1 callback cleanup
  SUNRPC: Fix svcauth_gss_proxy_init()
  SUNRPC: Trace gssproxy upcall results
  sunrpc: fix crash when cache_head become valid before update
  nfsd: remove private bin2hex implementation
  ...

Pull NFS client updates from Trond Myklebust:
 "Highlights include:

  Features:

   - NFSv4.2 now supports cross device offloaded copy (i.e. offloaded
     copy of a file from one source server to a different target
     server).

   - New RDMA tracepoints for debugging congestion control and Local
     Invalidate WRs.

  Bugfixes and cleanups

   - Drop the NFSv4.1 session slot if nfs4_delegreturn_prepare waits for
     layoutreturn

   - Handle bad/dead sessions correctly in nfs41_sequence_process()

   - Various bugfixes to the delegation return operation.

   - Various bugfixes pertaining to delegations that have been revoked.

   - Cleanups to the NFS timespec code to avoid unnecessary conversions
     between timespec and timespec64.

   - Fix unstable RDMA connections after a reconnect

   - Close race between waking an RDMA sender and posting a receive

   - Wake pending RDMA tasks if connection fails

   - Fix MR list corruption, and clean up MR usage

   - Fix another RPCSEC_GSS issue with MIC buffer space"

* tag 'nfs-for-5.5-1' of git://git.linux-nfs.org/projects/trondmy/linux-nfs: (79 commits)
  SUNRPC: Capture completion of all RPC tasks
  SUNRPC: Fix another issue with MIC buffer space
  NFS4: Trace lock reclaims
  NFS4: Trace state recovery operation
  NFSv4.2 fix memory leak in nfs42_ssc_open
  NFSv4.2 fix kfree in __nfs42_copy_file_range
  NFS: remove duplicated include from nfs4file.c
  NFSv4: Make _nfs42_proc_copy_notify() static
  NFS: Fallocate should use the nfs4_fattr_bitmap
  NFS: Return -ETXTBSY when attempting to write to a swapfile
  fs: nfs: sysfs: Remove NULL check before kfree
  NFS: remove unneeded semicolon
  NFSv4: add declaration of current_stateid
  NFSv4.x: Drop the slot if nfs4_delegreturn_prepare waits for layoutreturn
  NFSv4.x: Handle bad/dead sessions correctly in nfs41_sequence_process()
  nfsv4: Move NFSPROC4_CLNT_COPY_NOTIFY to end of list
  SUNRPC: Avoid RPC delays when exiting suspend
  NFS: Add a tracepoint in nfs_fh_to_dentry()
  NFSv4: Don't retry the GETATTR on old stateid in nfs4_delegreturn_done()
  NFSv4: Handle NFS4ERR_OLD_STATEID in delegreturn
  ...

We had cases in the previous patch where we were sending the security
descriptor context on SMB3 open (file create) in cases when we hadn't
mounted with with "modefromsid" mount option.

Add check for that mount flag before calling ad_sd_context in
open init.
Signed-off-by: Steve French <stfrench@microsoft.com>
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>

Pull VFIO updates from Alex Williamson:

 - Remove hugepage checks for reserved pfns (Ben Luo)

 - Fix irq-bypass unregister ordering (Jiang Yi)

* tag 'vfio-v5.5-rc1' of git://github.com/awilliam/linux-vfio:
  vfio/pci: call irq_bypass_unregister_producer() before freeing irq
  vfio/type1: remove hugepage checks in is_invalid_reserved_pfn()

Pull more xen updates from Juergen Gross:

 - a patch to fix a build warning

 - a cleanup of no longer needed code in the Xen event handling

 - a small series for the Xen grant driver avoiding high order
   allocations and replacing an insane global limit by a per-call one

 - a small series fixing Xen frontend/backend module referencing

* tag 'for-linus-5.5b-rc1-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip:
  xen-blkback: allow module to be cleanly unloaded
  xen/xenbus: reference count registered modules
  xen/gntdev: switch from kcalloc() to kvcalloc()
  xen/gntdev: replace global limit of mapped pages by limit per call
  xen/gntdev: remove redundant non-zero check on ret
  xen/events: remove event handling recursion detection

Merge misc Kconfig updates from Andrew Morton:
 "A number of changes to Kconfig files under lib/ from Changbin Du and
  Krzysztof Kozlowski"

* emailed patches from Andrew Morton <akpm@linux-foundation.org>:
  lib/: fix Kconfig indentation
  kernel-hacking: move DEBUG_FS to 'Generic Kernel Debugging Instruments'
  kernel-hacking: move DEBUG_BUGVERBOSE to 'printk and dmesg options'
  kernel-hacking: create a submenu for scheduler debugging options
  kernel-hacking: move SCHED_STACK_END_CHECK after DEBUG_STACK_USAGE
  kernel-hacking: move Oops into 'Lockups and Hangs'
  kernel-hacking: move kernel testing and coverage options to same submenu
  kernel-hacking: group kernel data structures debugging together
  kernel-hacking: create submenu for arch special debugging options
  kernel-hacking: group sysrq/kgdb/ubsan into 'Generic Kernel Debugging Instruments'

In referenced fix we removed the RTL8168e-specific jumbo config for
RTL8168evl in rtl_hw_jumbo_enable(). We have to do the same in
rtl_hw_jumbo_disable().

v2: fix referenced commit id

Fixes: 14012c9f ("r8169: fix jumbo configuration for RTL8168evl")
Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

pipe_wait() may be simple, but since it relies on the pipe lock, it
means that we have to do the wakeup while holding the lock.  That's
unfortunate, because the very first thing the waked entity will want to
do is to get the pipe lock for itself.

So get rid of the pipe_wait() usage by simply releasing the pipe lock,
doing the wakeup (if required) and then using wait_event_interruptible()
to wait on the right condition instead.

wait_event_interruptible() handles races on its own by comparing the
wakeup condition before and after adding itself to the wait queue, so
you can use an optimistic unlocked condition for it.

Cc: David Howells <dhowells@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Signed-off-by: Jiasen Lin <linjiasen@hygon.cn>
Signed-off-by: Jon Mason <jdmason@kudzu.us>

This code is ancient, and goes back to when we only had a single page
for the pipe buffers.  The exact history is hidden in the mists of time
(ie "before git", and in fact predates the BK repository too).

At that long-ago point in time, it actually helped to try to merge big
back-and-forth pipe reads and writes, and not limit pipe reads to the
single pipe buffer in length just because that was all we had at a time.

However, since then we've expanded the pipe buffers to multiple pages,
and this logic really doesn't seem to make sense.  And a lot of it is
somewhat questionable (ie "hmm, the user asked for a non-blocking read,
but we see that there's a writer pending, so let's wait anyway to get
the extra data that the writer will have").

But more importantly, it makes the "go to sleep" logic much less
obvious, and considering the wakeup issues we've had, I want to make for
less of those kinds of things.

Cc: David Howells <dhowells@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

This is the read side version of the previous commit: it simplifies the
logic to only wake up waiting writers when necessary, and makes sure to
use a synchronous wakeup.  This time not so much for GNU make jobserver
reasons (that pipe never fills up), but simply to get the writer going
quickly again.

A bit less verbose commentary this time, if only because I assume that
the write side commentary isn't going to be ignored if you touch this
code.

Cc: David Howells <dhowells@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

The pipe rework ends up having been extra painful, partly becaused of
actual bugs with ordering and caching of the pipe state, but also
because of subtle performance issues.

In particular, the pipe rework caused the kernel build to inexplicably
slow down.

The reason turns out to be that the GNU make jobserver (which limits the
parallelism of the build) uses a pipe to implement a "token" system: a
parallel submake will read a character from the pipe to get the job
token before starting a new job, and will write a character back to the
pipe when it is done.  The overall job limit is thus easily controlled
by just writing the appropriate number of initial token characters into
the pipe.

But to work well, that really means that the old behavior of write
wakeups being synchronous (WF_SYNC) is very important - when the pipe
writer wakes up a reader, we want the reader to actually get scheduled
immediately.  Otherwise you lose the parallelism of the build.

The pipe rework lost that synchronous wakeup on write, and we had
clearly all forgotten the reasons and rules for it.

This rewrites the pipe write wakeup logic to do the required Wsync
wakeups, but also clarifies the logic and avoids extraneous wakeups.

It also ends up addign a number of comments about what oit does and why,
so that we hopefully don't end up forgetting about this next time we
change this code.

Cc: David Howells <dhowells@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>