: error: C++ style comments are not allowed in ISO C90
 // Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.
 ^
error: (this will be reported only once per input file)

Signed-off-by: Guo Ren <guoren@linux.alibaba.com>

The existing code is essentially
free_initmem_default()->free_reserved_area() without poisoning.

Note that existing code missed to update the managed page count of the
zone.

Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Wei Yang <richard.weiyang@linux.alibaba.com>
Tested-by: Guo Ren <guoren@kernel.org>
Signed-off-by: Guo Ren <guoren@kernel.org>
Signed-off-by: David Hildenbrand <david@redhat.com>

The max_mapnr is the number of PFNs, not absolute PFN offset.
Using set_max_mapnr API instead of setting the value directly.

Signed-off-by: Guo Ren <guoren@linux.alibaba.com>

It could help to reduce the latency of the time-related functions
in user space.

We have referenced arm's and riscv's implementation for the patch.

Signed-off-by: Guo Ren <guoren@linux.alibaba.com>
Cc: Vincent Chen <vincent.chen@sifive.com>
Cc: Arnd Bergmann <arnd@arndb.de>

The type of 'val' is 'unsigned long' in simulate_blz32, so 'val < 0'
can't be true.

Cast 'val' to 'long' here to determine branch token or not,

Fixup instructions: bnezad32, bhsz32, bhz32, blsz32, blz32

Link: https://lore.kernel.org/linux-csky/CAJF2gTQjKXR9gpo06WAWG1aquiT87mATiMGorXs6ChxOxoe90Q@mail.gmail.com/T/#t


Signed-off-by: Guo Ren <guoren@linux.alibaba.com>
Co-developed-by: Menglong Dong <dong.menglong@zte.com.cn>
Signed-off-by: Menglong Dong <dong.menglong@zte.com.cn>

Current csky's swappon is broken by wrong swap PTE entry format.
Now redesign the new format for abiv1 & abiv2 and make swappon +
zram work properly on csky machines.

C-SKY PTE has VALID, DIRTY to emulate PRESENT, READ, WRITE, EXEC
attributes. GLOBAL bit is shared by two pages in the same tlb
entry. So we need to keep GLOBAL, VALID, PRESENT zero in swp_pte.

To distinguish PAGE_NONE and swp_pte, we need to use an additional
bit (abiv1 is _PAGE_READ, abiv2 is _PAGE_WRITE).

Signed-off-by: Guo Ren <guoren@linux.alibaba.com>
Cc: Arnd Bergmann <arnd@arndb.de>

C-SKY page table attributes only have 'Dirty' and 'Valid' to
emulate 'PRESENT, READ, WRITE, EXEC, DIRTY, ACCESSED'.

This patch cleanup unnecessary definition.

Signed-off-by: Guo Ren <guoren@linux.alibaba.com>
Cc: Arnd Bergmann <arnd@arndb.de>

When the system memory is exhausted, linux will trigger kswapd to
shrink memory page cache. We found the csky's .text file mapping
pages would be reclaimed earlier than arm's elf. Because csky
doesn't give _PAGE_ACCESSED for default pgprot and in zap_pte_range

if (pte_young(ptent) &&
    likely(!(vma->vm_flags & VM_SEQ_READ)))
        mark_page_accessed(page);

mark_page_accessed will put the pages into active lru list.

[    3.652722] delete busybox page from inactive file list
Call Trace:
[<9012a376>] dump_stack+0xe/0x24
[<9012a370>] dump_stack+0x8/0x24
[<9005b780>] activate_page+0x2b4/0x2d4
[<90132502>] vsnprintf+0x2c6/0x374
[<9005b880>] mark_page_accessed+0xe0/0x150
[<9006903e>] unmap_page_range+0x166/0x33c
[<90021844>] get_signal+0x98/0x3b4
[<90069232>] unmap_single_vma+0x1e/0x24
[<90069462>] unmap_vmas+0x26/0x40
[<9006d3d8>] exit_mmap+0x60/0xbc
[<9006a140>] handle_mm_fault+0x700/0xcec
[<900426b2>] ktime_get_with_offset+0x86/0x130
[<90017566>] mmput+0x2e/0x90
[<9001a30a>] do_exit+0x13e/0x6f0
[<90015448>] page_fault_end+0x14/0x74
[<9001b4bc>] SyS_exit_group+0x0/0xc
[<9001b47c>] do_group_exit+0x2c/0x6c
[<9001b4c8>] __wake_up_parent+0x0/0x20
[<9001399e>] csky_systemcall+0x6e/0x72

csky will throw the pages at first and keep them in active lru
list later after real accessed, but arm would keep them in active
lru list at the beginning.

The following are statistics of different architecture styles:

Default _PAGE_ACCESSED: alpha, arm, arm64, ia64, m68k, microblaze,
			openrisc, powerpc, riscv, sh, um, x86,
			xtensa
Not def _PAGE_ACCESSED: arc, c6x, h8300, hexgon, mips, s390, nds32,
			nios2, parisc, sparc

Signed-off-by: Guo Ren <guoren@linux.alibaba.com>
Co-developed-by: Xu Kai <xukai@nationalchip.com>
Signed-off-by: Xu Kai <xukai@nationalchip.com>

Remove including <linux/version.h> that don't need it.

Signed-off-by: Tian Tao <tiantao6@hisilicon.com>
Signed-off-by: Guo Ren <guoren@linux.alibaba.com>

"*" is missed  in size determination as we are passing register set
rather than a pointer.

Fixes: dcad7854

 ("sky: switch to ->regset_get()")
Signed-off-by: Zhenzhong Duan <zhenzhong.duan@gmail.com>
Signed-off-by: Guo Ren <guoren@linux.alibaba.com>

Reconstruct vdso framework to support future vsyscall,
vgettimeofday features. These are very important features to reduce
system calls into the kernel for performance improvement.

The patch is reference RISC-V's

Signed-off-by: Guo Ren <guoren@linux.alibaba.com>
Cc: Palmer Dabbelt <palmerdabbelt@google.com>

Pick up the patch from the 'Link' made by Mark Rutland. Keep the
same with x86, arm, arm64, arc, sh, power.

Link: https://lore.kernel.org/linux-arm-kernel/1499782763-31418-1-git-send-email-mark.rutland@arm.com/


Signed-off-by: Guo Ren <guoren@linux.alibaba.com>
Cc: Mark Rutland <mark.rutland@arm.com>

Sync arch/riscv/mm/fault.c into arch/csky for easy maintenance.
Here are the patches related to the modification:

cac4d1dc "riscv/mm/fault: Move no context handling to no_context()"
ac416a72 "riscv/mm/fault: Move vmalloc fault handling to vmalloc_fault()"
6c11ffbf "riscv/mm/fault: Move fault error handling to mm_fault_error()"
afb8c6fe "riscv/mm/fault: Move access error check to function"
bda281d5 "riscv/mm/fault: Simplify fault error handling"
a51271d9

 "riscv/mm/fault: Move bad area handling to bad_area()"

Signed-off-by: Guo Ren <guoren@linux.alibaba.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Palmer Dabbelt <palmerdabbelt@google.com>
Cc: Arnd Bergmann <arnd@arndb.de>

We must succeed parent's context irq status in page fault handler.

Signed-off-by: Guo Ren <guoren@linux.alibaba.com>

Similar to other architectures:
In addition to in_atomic, we also need pagefault_disabled() to
check.

Signed-off-by: Guo Ren <guoren@linux.alibaba.com>

The function update_mmu_cache could be called by user-io mapping.
There is no space of struct page in mem_map for the pte. Just
ignore the user-io mmaping in update_mmu_cache.

Signed-off-by: Guo Ren <guoren@linux.alibaba.com>

The past code only passes the FAULT_FLAG_WRITE into
handle_mm_fault and missing USER & DEFAULT & RETRY.

The patch references to arch/riscv/mm/fault.c, but there is no
FAULT_FLAG_INSTRUCTION in csky hw.

Signed-off-by: Guo Ren <guoren@linux.alibaba.com>

Print all 1024 jtlb entries and 16 iutlb entries and 16 dutlb
entries in show_regs.

Signed-off-by: Guo Ren <guoren@linux.alibaba.com>

TLB invalidate didn't contain a barrier operation in csky cpu and
we need to prevent previous PTW response after TLB invalidation
instruction. Of cause, the ASID changing also needs to take care
of the issue.

CPU0                    CPU1
===============         ===============
set_pte
sync_is()        ->     See the previous set_pte for all harts
tlbi.vas         ->     Invalidate all harts TLB entry & flush pipeline

Signed-off-by: Guo Ren <guoren@linux.alibaba.com>

Here is the log after enabled:

[    1.798972] kmemleak: Kernel memory leak detector initialized (mem pool available: 15851)
[    1.798983] kmemleak: Automatic memory scanning thread started

Signed-off-by: Guo Ren <guoren@linux.alibaba.com>

There is a prologue on page fault handler which marking pages dirty
and/or accessed in page attributes, but all of these have been
handled in handle_pte_fault.

 - Add flush_tlb_one in vmalloc page fault instead of prologue.
 - Using cmxchg_fixup C codes in do_page_fault instead of ASM one.

Signed-off-by: Guo Ren <guoren@linux.alibaba.com>

Fixup commit c2d1adfa9a24 "csky: Add memory layout 2.5G(user):1.5G
(kernel)". That patch broke the global bit in PTE.

C-SKY TLB's entry contain two pages:
vpn, vpn + 1 -> ppn0, ppn1

All PPN's attributes contain global bit and final global is PPN0.G
& PPN1.G. So we must keep PPN0.G and PPN1.G same in one TLB's
entry.

Signed-off-by: Guo Ren <guoren@linux.alibaba.com>

There are two implementation of spinlock in arch/csky:
 - simple one (NR_CPU = 1,2)
 - tick's one (NR_CPU = 3,4)
Remove the simple one.

There is already smp_mb in spinlock, so remove the definition of
smp_mb__after_spinlock.

Link: https://lore.kernel.org/linux-csky/20200807081253.GD2674@hirez.programming.kicks-ass.net/#t


Signed-off-by: Guo Ren <guoren@linux.alibaba.com>
Cc: Peter Zijlstra <peterz@infradead.org>k
Cc: Arnd Bergmann <arnd@arndb.de>

Optimize the performance of cmpxchg by using more fine-grained
acquire/release barriers.

Signed-off-by: Guo Ren <guoren@linux.alibaba.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Paul E. McKenney <paulmck@kernel.org>

Arnd said:
I would guess that for csky, this is a mistake, as the architecture
is fairly new and should be able to implement it.

Guo reply:
The c610, c807, c810 don't support SMP, so futex_cmpxchg_enabled = 1
with asm-generic's implementation.
For c860, there is no HAVE_FUTEX_CMPXCHG and cmpxchg_inatomic/inuser
implementation, so futex_cmpxchg_enabled = 0.

Thx for point it out, we'll implement cmpxchg_inatomic/inuser for
C860 and still use asm-generic for non-smp CPUs.

LTP test:
futex_wait01    1  TPASS  :  futex_wait(): errno=ETIMEDOUT(110): Connection timed out
futex_wait01    2  TPASS  :  futex_wait(): errno=EAGAIN/EWOULDBLOCK(11): Resource temporarily unavailable
futex_wait01    3  TPASS  :  futex_wait(): errno=ETIMEDOUT(110): Connection timed out
futex_wait01    4  TPASS  :  futex_wait(): errno=EAGAIN/EWOULDBLOCK(11): Resource temporarily unavailable
futex_wait02    1  TPASS  :  futex_wait() woken up
futex_wait03    1  TPASS  :  futex_wait() woken up
futex_wait04    1  TPASS  :  futex_wait() returned -1: errno=EAGAIN/EWOULDBLOCK(11): Resource temporarily unavailable

Signed-off-by: Guo Ren <guoren@linux.alibaba.com>
Cc: Arnd Bergmann <arnd@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Paul E. McKenney <paulmck@kernel.org>
Link: https://lore.kernel.org/lkml/CAK8P3a3+WaQNyJ6Za2qfu6=0mBgU1hApnRXrdp1b1=P7wwyRUg@mail.gmail.com/

Remove shareable bit for ordering barrier, just keep ordering
in current hart is enough for SMP. Using three continuous
sync.is as PTW barrier to prevent speculative PTW in 860
microarchitecture.

Signed-off-by: Guo Ren <guoren@linux.alibaba.com>

Use generic atomic implementation based on cmpxchg. So remove csky
asm/atomic.h.

Signed-off-by: Guo Ren <guoren@linux.alibaba.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Arnd Bergmann <arnd@kernel.org>
Cc: Paul E. McKenney <paulmck@kernel.org>

Current show_regs didn't display regs->usp and it confused debug.
So fixup wrong SP display and add PT_REGS.

Signed-off-by: Guo Ren <guoren@linux.alibaba.com>

Current perf init will failed with:
[    1.452433] csky-pmu: probe of soc:pmu failed with error -16

This patch fix it up with adding CPUHP_AP_PERF_CSKY_ONLINE in
cpuhotplug.h.

Signed-off-by: Guo Ren <guoren@linux.alibaba.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>

There are two ways for translating va to pa for csky:
 - Use TLB(Translate Lookup Buffer) and PTW (Page Table Walk)
 - Use SSEG0/1 (Simple Segment Mapping)

We use tlb mapping 0-2G and 3G-4G virtual address area and SSEG0/1
are for 2G-2.5G and 2.5G-3G translation. We could disable SSEG0
to use 2G-2.5G as TLB user mapping.

Signed-off-by: Guo Ren <guoren@linux.alibaba.com>

Merge tag 'kbuild-fixes-v5.11' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild

Pull Kbuild fixes from Masahiro Yamada:

 - Search for <ncurses.h> in the default header path of HOSTCC

 - Tweak the option order to be kind to old BSD awk

 - Remove 'kvmconfig' and 'xenconfig' shorthands

 - Fix documentation

* tag 'kbuild-fixes-v5.11' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild:
  Documentation: kbuild: Fix section reference
  kconfig: remove 'kvmconfig' and 'xenconfig' shorthands
  lib/raid6: Let $(UNROLL) rules work with macOS userland
  kconfig: Support building mconf with vendor sysroot ncurses
  kconfig: config script: add a little user help
  MAINTAINERS: adjust GCC PLUGINS after gcc-plugin.sh removal

Pull SCSI fixes from James Bottomley:
 "This is two driver fixes (megaraid_sas and hisi_sas).

  The megaraid one is a revert of a previous revert of a cpu hotplug fix
  which exposed a bug in the block layer which has been fixed in this
  merge window.

  The hisi_sas performance enhancement comes from switching to interrupt
  managed completion queues, which depended on the addition of
  devm_platform_get_irqs_affinity() which is now upstream via the irq
  tree in the last merge window"

* tag 'scsi-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi:
  scsi: hisi_sas: Expose HW queues for v2 hw
  Revert "Revert "scsi: megaraid_sas: Added support for shared host tagset for cpuhotplug""

Pull block fixes from Jens Axboe:

 - Missing CRC32 selections (Arnd)

 - Fix for a merge window regression with bdev inode init (Christoph)

 - bcache fixes

 - rnbd fixes

 - NVMe pull request from Christoph:
    - fix a race in the nvme-tcp send code (Sagi Grimberg)
    - fix a list corruption in an nvme-rdma error path (Israel Rukshin)
    - avoid a possible double fetch in nvme-pci (Lalithambika Krishnakumar)
    - add the susystem NQN quirk for a Samsung driver (Gopal Tiwari)
    - fix two compiler warnings in nvme-fcloop (James Smart)
    - don't call sleeping functions from irq context in nvme-fc (James Smart)
    - remove an unused argument (Max Gurtovoy)
    - remove unused exports (Minwoo Im)

 - Use-after-free fix for partition iteration (Ming)

 - Missing blk-mq debugfs flag annotation (John)

 - Bdev freeze regression fix (Satya)

 - blk-iocost NULL pointer deref fix (Tejun)

* tag 'block-5.11-2021-01-10' of git://git.kernel.dk/linux-block: (26 commits)
  bcache: set bcache device into read-only mode for BCH_FEATURE_INCOMPAT_OBSO_LARGE_BUCKET
  bcache: introduce BCH_FEATURE_INCOMPAT_LOG_LARGE_BUCKET_SIZE for large bucket
  bcache: check unsupported feature sets for bcache register
  bcache: fix typo from SUUP to SUPP in features.h
  bcache: set pdev_set_uuid before scond loop iteration
  blk-mq-debugfs: Add decode for BLK_MQ_F_TAG_HCTX_SHARED
  block/rnbd-clt: avoid module unload race with close confirmation
  block/rnbd: Adding name to the Contributors List
  block/rnbd-clt: Fix sg table use after free
  block/rnbd-srv: Fix use after free in rnbd_srv_sess_dev_force_close
  block/rnbd: Select SG_POOL for RNBD_CLIENT
  block: pre-initialize struct block_device in bdev_alloc_inode
  fs: Fix freeze_bdev()/thaw_bdev() accounting of bd_fsfreeze_sb
  nvme: remove the unused status argument from nvme_trace_bio_complete
  nvmet-rdma: Fix list_del corruption on queue establishment failure
  nvme: unexport functions with no external caller
  nvme: avoid possible double fetch in handling CQE
  nvme-tcp: Fix possible race of io_work and direct send
  nvme-pci: mark Samsung PM1725a as IGNORE_DEV_SUBNQN
  nvme-fcloop: Fix sscanf type and list_first_entry_or_null warnings
  ...

Pull io_uring fixes from Jens Axboe:
 "A bit larger than I had hoped at this point, but it's all changes that
  will be directed towards stable anyway. In detail:

   - Fix a merge window regression on error return (Matthew)

   - Remove useless variable declaration/assignment (Ye Bin)

   - IOPOLL fixes (Pavel)

   - Exit and cancelation fixes (Pavel)

   - fasync lockdep complaint fix (Pavel)

   - Ensure SQPOLL is synchronized with creator life time (Pavel)"

* tag 'io_uring-5.11-2021-01-10' of git://git.kernel.dk/linux-block:
  io_uring: stop SQPOLL submit on creator's death
  io_uring: add warn_once for io_uring_flush()
  io_uring: inline io_uring_attempt_task_drop()
  io_uring: io_rw_reissue lockdep annotations
  io_uring: synchronise ev_posted() with waitqueues
  io_uring: dont kill fasync under completion_lock
  io_uring: trigger eventfd for IOPOLL
  io_uring: Fix return value from alloc_fixed_file_ref_node
  io_uring: Delete useless variable ‘id’ in io_prep_async_work
  io_uring: cancel more aggressively in exit_work
  io_uring: drop file refs after task cancel
  io_uring: patch up IOPOLL overflow_flush sync
  io_uring: synchronise IOPOLL on task_submit fail

Pull USB fixes from Greg KH:
 "Here are a number of small USB driver fixes for 5.11-rc3.

  Include in here are:

   - USB gadget driver fixes for reported issues

   - new usb-serial driver ids

   - dma from stack bugfixes

   - typec bugfixes

   - dwc3 bugfixes

   - xhci driver bugfixes

   - other small misc usb driver bugfixes

  All of these have been in linux-next with no reported issues"

* tag 'usb-5.11-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb: (35 commits)
  usb: dwc3: gadget: Clear wait flag on dequeue
  usb: typec: Send uevent for num_altmodes update
  usb: typec: Fix copy paste error for NVIDIA alt-mode description
  usb: gadget: enable super speed plus
  kcov, usb: hide in_serving_softirq checks in __usb_hcd_giveback_urb
  usb: uas: Add PNY USB Portable SSD to unusual_uas
  usb: gadget: configfs: Preserve function ordering after bind failure
  usb: gadget: select CONFIG_CRC32
  usb: gadget: core: change the comment for usb_gadget_connect
  usb: gadget: configfs: Fix use-after-free issue with udc_name
  usb: dwc3: gadget: Restart DWC3 gadget when enabling pullup
  usb: usbip: vhci_hcd: protect shift size
  USB: usblp: fix DMA to stack
  USB: serial: iuu_phoenix: fix DMA from stack
  USB: serial: option: add LongSung M5710 module support
  USB: serial: option: add Quectel EM160R-GL
  USB: Gadget: dummy-hcd: Fix shift-out-of-bounds bug
  usb: gadget: f_uac2: reset wMaxPacketSize
  usb: dwc3: ulpi: Fix USB2.0 HS/FS/LS PHY suspend regression
  usb: dwc3: ulpi: Replace CPU-based busyloop with Protocol-based one
  ...

Pull staging driver fixes from Greg KH:
 "Here are some small staging driver fixes for 5.11-rc3. Nothing major,
  just resolving some reported issues:

   - cleanup some remaining mentions of the ION drivers that were
     removed in 5.11-rc1

   - comedi driver bugfix

   - two error path memory leak fixes

  All have been in linux-next for a while with no reported issues"

* tag 'staging-5.11-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging:
  staging: ION: remove some references to CONFIG_ION
  staging: mt7621-dma: Fix a resource leak in an error handling path
  Staging: comedi: Return -EFAULT if copy_to_user() fails
  staging: spmi: hisi-spmi-controller: Fix some error handling paths

Pull char/misc driver fixes from Greg KH:
 "Here are some small char and misc driver fixes for 5.11-rc3.

  The majority here are fixes for the habanalabs drivers, but also in
  here are:

   - crypto driver fix

   - pvpanic driver fix

   - updated font file

   - interconnect driver fixes

  All of these have been in linux-next for a while with no reported
  issues"

* tag 'char-misc-5.11-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc: (26 commits)
  Fonts: font_ter16x32: Update font with new upstream Terminus release
  misc: pvpanic: Check devm_ioport_map() for NULL
  speakup: Add github repository URL and bug tracker
  MAINTAINERS: Update Georgi's email address
  crypto: asym_tpm: correct zero out potential secrets
  habanalabs: Fix memleak in hl_device_reset
  interconnect: imx8mq: Use icc_sync_state
  interconnect: imx: Remove a useless test
  interconnect: imx: Add a missing of_node_put after of_device_is_available
  interconnect: qcom: fix rpmh link failures
  habanalabs: fix order of status check
  habanalabs: register to pci shutdown callback
  habanalabs: add validation cs counter, fix misplaced counters
  habanalabs/gaudi: retry loading TPC f/w on -EINTR
  habanalabs: adjust pci controller init to new firmware
  habanalabs: update comment in hl_boot_if.h
  habanalabs/gaudi: enhance reset message
  habanalabs: full FW hard reset support
  habanalabs/gaudi: disable CGM at HW initialization
  habanalabs: Revise comment to align with mirror list name
  ...

Section 3.11 was incorrectly called 3.9, fix it.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>

Pull ARC fixes from Vineet Gupta:

 - Address the 2nd boot failure due to snafu in signal handling code
   (first was generic console ttynull issue)

 - misc other fixes

* tag 'arc-5.11-rc3-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/vgupta/arc:
  ARC: [hsdk]: Enable FPU_SAVE_RESTORE
  ARC: unbork 5.11 bootup: fix snafu in _TIF_NOTIFY_SIGNAL handling
  include/soc: remove headers for EZChip NPS
  arch/arc: add copy_user_page() to <asm/page.h> to fix build error on ARC