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  1. 24 Jan, 2016 1 commit
    • Huacai Chen's avatar
      MIPS: sync-r4k: reduce skew while synchronization · db0dbd57
      Huacai Chen authored 
      While synchronization, count register will go backwards for the master.
If synchronise_count_master() runs before synchronise_count_slave(),
skew becomes even more. The skew is very harmful for CPU hotplug (CPU0
do synchronization with CPU1, then CPU0 do synchronization with CPU2
and CPU0's count goes backwards, so it will be out of sync with CPU1).

After the commit cf9bfe55 (MIPS: Synchronize MIPS count one
CPU at a time), we needn't evaluate count_reference at the beginning of
synchronise_count_master() any more. Thus, we evaluate the initcount (It
seems like count_reference is redundant) in the 2nd loop. Since we write
the count register in the last loop, we don't need additional barriers
(the existing memory barriers are enough).

Moreover, I think we loop 3 times is enough to get a primed instruction
cache, this can also get less skew than looping 5 times.

Comments are also updated in this patch.
Signed-off-by: default avatarHuacai Chen <chenhc@lemote.com>
Cc: Aurelien Jarno <aurelien@aurel32.net>
Cc: Steven J. Hill <Steven.Hill@imgtec.com>
Cc: linux-mips@linux-mips.org
Cc: Fuxin Zhang <zhangfx@lemote.com>
Cc: Zhangjin Wu <wuzhangjin@gmail.com>
Patchwork: https://patchwork.linux-mips.org/patch/12163/Signed-off-by: default avatarRalf Baechle <ralf@linux-mips.org>
      db0dbd57
  3. 22 Jan, 2016 4 commits
    • Huacai Chen's avatar
      MIPS: hpet: Choose a safe value for the ETIME check · 5610b125
      Huacai Chen authored 
      This patch is borrowed from x86 hpet driver and explaind below:

Due to the overly intelligent design of HPETs, we need to workaround
the problem that the compare value which we write is already behind
the actual counter value at the point where the value hits the real
compare register. This happens for two reasons:

1) We read out the counter, add the delta and write the result to the
   compare register. When a NMI hits between the read out and the write
   then the counter can be ahead of the event already.

2) The write to the compare register is delayed by up to two HPET
   cycles in AMD chipsets.

We can work around this by reading back the compare register to make
sure that the written value has hit the hardware. But that is bad
performance wise for the normal case where the event is far enough in
the future.

As we already know that the write can be delayed by up to two cycles
we can avoid the read back of the compare register completely if we
make the decision whether the delta has elapsed already or not based
on the following calculation:

  cmp = event - actual_count;

If cmp is less than 64 HPET clock cycles, then we decide that the event
has happened already and return -ETIME. That covers the above #1 and #2
problems which would cause a wait for HPET wraparound (~306 seconds).
Signed-off-by: default avatarHuacai Chen <chenhc@lemote.com>
Cc: Aurelien Jarno <aurelien@aurel32.net>
Cc: Steven J. Hill <Steven.Hill@imgtec.com>
Cc: Fuxin Zhang <zhangfx@lemote.com>
Cc: Zhangjin Wu <wuzhangjin@gmail.com>
Cc: Huacai Chen <chenhc@lemote.com>
Cc: linux-mips@linux-mips.org
Cc: stable@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/12162/Signed-off-by: default avatarRalf Baechle <ralf@linux-mips.org>
      5610b125
    • Huacai Chen's avatar
      MIPS: Loongson-3: Fix SMP_ASK_C0COUNT IPI handler · 57548432
      Huacai Chen authored 
      When Core-0 handle SMP_ASK_C0COUNT IPI, we should make other cores to
see the result as soon as possible (especially when Store-Fill-Buffer
is enabled). Otherwise, C0_Count syncronization makes no sense.

BTW, array is more suitable than per-cpu variable for syncronization,
and there is a corner case should be avoid: C0_Count of Core-0 can be
really 0.
Signed-off-by: default avatarHuacai Chen <chenhc@lemote.com>
Cc: Aurelien Jarno <aurelien@aurel32.net>
Cc: Steven J. Hill <Steven.Hill@imgtec.com>
Cc: Fuxin Zhang <zhangfx@lemote.com>
Cc: Zhangjin Wu <wuzhangjin@gmail.com>
Cc: Huacai Chen <chenhc@lemote.com>
Cc: linux-mips@linux-mips.org
Cc: <stable@vger.kernel.org>
Patchwork: https://patchwork.linux-mips.org/patch/12160/Signed-off-by: default avatarRalf Baechle <ralf@linux-mips.org>
      57548432
    • Huacai Chen's avatar
      MIPS: Loongson-3: Improve -march option and move it to Platform · 5188129b
      Huacai Chen authored 
      If GCC >= 4.9 and Binutils >=2.25, we use -march=loongson3a, otherwise
we use -march=mips64r2, this can slightly improve performance. Besides,
arch/mips/loongson64/Platform is a better location rather than arch/
mips/Makefile.
Signed-off-by: default avatarHuacai Chen <chenhc@lemote.com>
Cc: Aurelien Jarno <aurelien@aurel32.net>
Cc: Steven J. Hill <Steven.Hill@imgtec.com>
Cc: Fuxin Zhang <zhangfx@lemote.com>
Cc: Zhangjin Wu <wuzhangjin@gmail.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/12161/Signed-off-by: default avatarRalf Baechle <ralf@linux-mips.org>
      5188129b
    • Huacai Chen's avatar
      MIPS: Cleanup the unused __arch_local_irq_restore() function · 6e526844
      Huacai Chen authored 
      In history, __arch_local_irq_restore() is only used by SMTC. However,
SMTC support has been removed since 3.16, this patch remove the unused
function.
Signed-off-by: default avatarHuacai Chen <chenhc@lemote.com>
Cc: Aurelien Jarno <aurelien@aurel32.net>
Cc: Steven J. Hill <Steven.Hill@imgtec.com>
Cc: Fuxin Zhang <zhangfx@lemote.com>
Cc: Zhangjin Wu <wuzhangjin@gmail.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/12159/Signed-off-by: default avatarRalf Baechle <ralf@linux-mips.org>
      6e526844
  5. 19 Jan, 2016 20 commits
  7. 04 Jan, 2016 9 commits
  9. 03 Jan, 2016 3 commits
  11. 31 Dec, 2015 3 commits
    • Linus Torvalds's avatar
      Merge tag 'pci-v4.4-fixes-3' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci · 9c982e86
      Linus Torvalds authored 
      Pull PCI bugfix from Bjorn Helgaas:
 "Here's another fix for v4.4.

  This fixes 32-bit config reads for the HiSilicon driver.  Obviously
  the driver is completely broken without this fix (apparently it
  actually was tested internally, but got broken somehow in the process
  of upstreaming it).

  Summary:

  HiSilicon host bridge driver
    Fix 32-bit config reads (Dongdong Liu)"

* tag 'pci-v4.4-fixes-3' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci:
  PCI: hisi: Fix hisi_pcie_cfg_read() 32-bit reads
      9c982e86
    • Linus Torvalds's avatar
      Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/sparc · 7c672dd6
      Linus Torvalds authored 
      Pull sparc fixes from David Miller:
 "Just some missing syscall wire ups"

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/sparc:
  sparc: Wire up mlock2 system call.
  sparc: Add all necessary direct socket system calls.
      7c672dd6
    • Linus Torvalds's avatar
      Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net · 8f5daf2a
      Linus Torvalds authored 
      Pull networking fixes from David Miller:

 1) Prevent XFRM per-cpu counter updates for one namespace from being
    applied to another namespace.  Fix from DanS treetman.

 2) Fix RCU de-reference in iwl_mvm_get_key_sta_id(), from Johannes
    Berg.

 3) Remove ethernet header assumption in nft_do_chain_netdev(), from
    Pablo Neira Ayuso.

 4) Fix cpsw PHY ident with multiple slaves and fixed-phy, from Pascal
    Speck.

 5) Fix use after free in sixpack_close and mkiss_close.

 6) Fix VXLAN fw assertion on bnx2x, from Yuval Mintz.

 7) natsemi doesn't check for DMA mapping errors, from Alexey
    Khoroshilov.

 8) Fix inverted test in ip6addrlbl_get(), from ANdrey Ryabinin.

 9) Missing initialization of needed_headroom in geneve tunnel driver,
    from Paolo Abeni.

10) Fix conntrack template leak in openvswitch, from Joe Stringer.

11) Mission initialization of wq->flags in sock_alloc_inode(), from
    Nicolai Stange.

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (35 commits)
  sctp: sctp should release assoc when sctp_make_abort_user return NULL in sctp_close
  net, socket, socket_wq: fix missing initialization of flags
  drivers: net: cpsw: fix error return code
  openvswitch: Fix template leak in error cases.
  sctp: label accepted/peeled off sockets
  sctp: use GFP_USER for user-controlled kmalloc
  qlcnic: fix a loop exit condition better
  net: cdc_ncm: avoid changing RX/TX buffers on MTU changes
  geneve: initialize needed_headroom
  ipv6: honor ifindex in case we receive ll addresses in router advertisements
  addrconf: always initialize sysctl table data
  ipv6/addrlabel: fix ip6addrlbl_get()
  switchdev: bridge: Pass ageing time as clock_t instead of jiffies
  sh_eth: fix 16-bit descriptor field access endianness too
  veth: don’t modify ip_summed; doing so treats packets with bad checksums as good.
  net: usb: cdc_ncm: Adding Dell DW5813 LTE AT&T Mobile Broadband Card
  net: usb: cdc_ncm: Adding Dell DW5812 LTE Verizon Mobile Broadband Card
  natsemi: add checks for dma mapping errors
  rhashtable: Kill harmless RCU warning in rhashtable_walk_init
  openvswitch: correct encoding of set tunnel action attributes
  ...
      8f5daf2a
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