[PATCH v2 00/21] Remove Mysterious Macro Intended to Obscure Weird Behaviours (mmiowb())

From: Will Deacon
Date: Fri Apr 05 2019 - 09:59:47 EST


Hi everybody,

This is version two of the patches I previously posted here:

RFC: https://lwn.net/ml/linux-kernel/20190222185026.10973-1-will.deacon@xxxxxxx/
v1: https://lkml.kernel.org/r/20190301140348.25175-1-will.deacon@xxxxxxx

I would really appreciate review comments and/or Acks on the first patch, since
it was that change which triggered the rest of the series and, without an ack,
it's holding the rest of the patches up.

Changes since v1 include:

* Move mmiowb_spin_{lock,unlock}() calls into the critical section
* Included memory-barriers.txt patch on which this lot depends
* Added acks
* Based on v5.1-rc3

I've also pushed this series out here:

git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-next/mmiowb

and I would like to get it into -next once the first patch has been acked.

Cheers,

Will

Cc: "Paul E. McKenney" <paulmck@xxxxxxxxxxxxx>
Cc: Benjamin Herrenschmidt <benh@xxxxxxxxxxxxxxxxxxx>
Cc: Michael Ellerman <mpe@xxxxxxxxxxxxxx>
Cc: Arnd Bergmann <arnd@xxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Andrea Parri <andrea.parri@xxxxxxxxxxxxxxxxxxxx>
Cc: Palmer Dabbelt <palmer@xxxxxxxxxx>
Cc: Daniel Lustig <dlustig@xxxxxxxxxx>
Cc: David Howells <dhowells@xxxxxxxxxx>
Cc: Alan Stern <stern@xxxxxxxxxxxxxxxxxxx>
Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Cc: "Maciej W. Rozycki" <macro@xxxxxxxxxxxxxx>
Cc: Paul Burton <paul.burton@xxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxxxxx>
Cc: Yoshinori Sato <ysato@xxxxxxxxxxxxxxxxxxxx>
Cc: Rich Felker <dalias@xxxxxxxx>
Cc: Tony Luck <tony.luck@xxxxxxxxx>
Cc: Mikulas Patocka <mpatocka@xxxxxxxxxx>
Cc: Akira Yokosawa <akiyks@xxxxxxxxx>
Cc: Luis Chamberlain <mcgrof@xxxxxxxxxx>
Cc: Nicholas Piggin <npiggin@xxxxxxxxx>

--->8

Will Deacon (21):
docs/memory-barriers.txt: Rewrite "KERNEL I/O BARRIER EFFECTS" section
asm-generic/mmiowb: Add generic implementation of mmiowb() tracking
arch: Use asm-generic header for asm/mmiowb.h
mmiowb: Hook up mmiowb helpers to spinlocks and generic I/O accessors
ARM/io: Remove useless definition of mmiowb()
arm64/io: Remove useless definition of mmiowb()
x86/io: Remove useless definition of mmiowb()
nds32/io: Remove useless definition of mmiowb()
m68k/io: Remove useless definition of mmiowb()
sh/mmiowb: Add unconditional mmiowb() to arch_spin_unlock()
mips/mmiowb: Add unconditional mmiowb() to arch_spin_unlock()
ia64/mmiowb: Add unconditional mmiowb() to arch_spin_unlock()
powerpc/mmiowb: Hook up mmwiob() implementation to asm-generic code
riscv/mmiowb: Hook up mmwiob() implementation to asm-generic code
Documentation: Kill all references to mmiowb()
drivers: Remove useless trailing comments from mmiowb() invocations
drivers: Remove explicit invocations of mmiowb()
scsi/qla1280: Remove stale comment about mmiowb()
i40iw: Redefine i40iw_mmiowb() to do nothing
net/ethernet/silan/sc92031: Remove stale comment about mmiowb()
arch: Remove dummy mmiowb() definitions from arch code

Documentation/driver-api/device-io.rst | 45 -----
Documentation/driver-api/pci/p2pdma.rst | 4 -
Documentation/memory-barriers.txt | 212 +++++++--------------
arch/alpha/include/asm/Kbuild | 1 +
arch/alpha/include/asm/io.h | 2 -
arch/arc/include/asm/Kbuild | 1 +
arch/arm/include/asm/Kbuild | 1 +
arch/arm/include/asm/io.h | 2 -
arch/arm64/include/asm/Kbuild | 1 +
arch/arm64/include/asm/io.h | 2 -
arch/c6x/include/asm/Kbuild | 1 +
arch/csky/include/asm/Kbuild | 1 +
arch/h8300/include/asm/Kbuild | 1 +
arch/hexagon/include/asm/Kbuild | 1 +
arch/hexagon/include/asm/io.h | 2 -
arch/ia64/include/asm/io.h | 17 --
arch/ia64/include/asm/mmiowb.h | 25 +++
arch/ia64/include/asm/spinlock.h | 2 +
arch/m68k/include/asm/Kbuild | 1 +
arch/m68k/include/asm/io_mm.h | 2 -
arch/microblaze/include/asm/Kbuild | 1 +
arch/mips/include/asm/io.h | 3 -
arch/mips/include/asm/mmiowb.h | 11 ++
arch/mips/include/asm/spinlock.h | 15 ++
arch/nds32/include/asm/Kbuild | 1 +
arch/nds32/include/asm/io.h | 2 -
arch/nios2/include/asm/Kbuild | 1 +
arch/openrisc/include/asm/Kbuild | 1 +
arch/parisc/include/asm/Kbuild | 1 +
arch/parisc/include/asm/io.h | 2 -
arch/powerpc/Kconfig | 1 +
arch/powerpc/include/asm/io.h | 33 +---
arch/powerpc/include/asm/mmiowb.h | 18 ++
arch/powerpc/include/asm/paca.h | 6 +-
arch/powerpc/include/asm/spinlock.h | 17 --
arch/powerpc/xmon/xmon.c | 5 +-
arch/riscv/Kconfig | 1 +
arch/riscv/include/asm/io.h | 15 +-
arch/riscv/include/asm/mmiowb.h | 14 ++
arch/s390/include/asm/Kbuild | 1 +
arch/sh/include/asm/io.h | 3 -
arch/sh/include/asm/mmiowb.h | 12 ++
arch/sh/include/asm/spinlock-llsc.h | 2 +
arch/sparc/include/asm/Kbuild | 1 +
arch/sparc/include/asm/io_64.h | 2 -
arch/um/include/asm/Kbuild | 1 +
arch/unicore32/include/asm/Kbuild | 1 +
arch/x86/include/asm/Kbuild | 1 +
arch/x86/include/asm/io.h | 2 -
arch/xtensa/include/asm/Kbuild | 1 +
drivers/crypto/cavium/nitrox/nitrox_reqmgr.c | 4 -
drivers/dma/txx9dmac.c | 3 -
drivers/firewire/ohci.c | 1 -
drivers/gpu/drm/i915/intel_hdmi.c | 10 -
drivers/ide/tx4939ide.c | 2 -
drivers/infiniband/hw/hfi1/chip.c | 3 -
drivers/infiniband/hw/hfi1/pio.c | 1 -
drivers/infiniband/hw/hns/hns_roce_hw_v1.c | 2 -
drivers/infiniband/hw/i40iw/i40iw_osdep.h | 2 +-
drivers/infiniband/hw/mlx4/qp.c | 6 -
drivers/infiniband/hw/mlx5/qp.c | 1 -
drivers/infiniband/hw/mthca/mthca_cmd.c | 6 -
drivers/infiniband/hw/mthca/mthca_cq.c | 5 -
drivers/infiniband/hw/mthca/mthca_qp.c | 17 --
drivers/infiniband/hw/mthca/mthca_srq.c | 6 -
drivers/infiniband/hw/qedr/verbs.c | 12 --
drivers/infiniband/hw/qib/qib_iba6120.c | 4 -
drivers/infiniband/hw/qib/qib_iba7220.c | 3 -
drivers/infiniband/hw/qib/qib_iba7322.c | 3 -
drivers/infiniband/hw/qib/qib_sd7220.c | 4 -
drivers/media/pci/dt3155/dt3155.c | 8 -
drivers/memstick/host/jmb38x_ms.c | 4 -
drivers/misc/ioc4.c | 2 -
drivers/misc/mei/hw-me.c | 3 -
drivers/misc/tifm_7xx1.c | 1 -
drivers/mmc/host/alcor.c | 1 -
drivers/mmc/host/sdhci.c | 13 --
drivers/mmc/host/tifm_sd.c | 3 -
drivers/mmc/host/via-sdmmc.c | 10 -
drivers/mtd/nand/raw/r852.c | 2 -
drivers/mtd/nand/raw/txx9ndfmc.c | 1 -
drivers/net/ethernet/aeroflex/greth.c | 1 -
drivers/net/ethernet/alacritech/slicoss.c | 4 -
drivers/net/ethernet/amazon/ena/ena_com.c | 1 -
drivers/net/ethernet/atheros/atlx/atl1.c | 1 -
drivers/net/ethernet/atheros/atlx/atl2.c | 1 -
drivers/net/ethernet/broadcom/bnx2.c | 4 -
drivers/net/ethernet/broadcom/bnx2x/bnx2x_cmn.c | 2 -
drivers/net/ethernet/broadcom/bnx2x/bnx2x_cmn.h | 4 -
.../net/ethernet/broadcom/bnx2x/bnx2x_ethtool.c | 1 -
drivers/net/ethernet/broadcom/bnx2x/bnx2x_main.c | 29 ---
drivers/net/ethernet/broadcom/bnx2x/bnx2x_sp.c | 1 -
drivers/net/ethernet/broadcom/bnx2x/bnx2x_sriov.c | 2 -
drivers/net/ethernet/broadcom/bnx2x/bnx2x_vfpf.c | 4 -
drivers/net/ethernet/broadcom/bnxt/bnxt.c | 3 -
drivers/net/ethernet/broadcom/tg3.c | 6 -
.../net/ethernet/cavium/liquidio/cn66xx_device.c | 10 -
.../net/ethernet/cavium/liquidio/octeon_device.c | 1 -
drivers/net/ethernet/cavium/liquidio/octeon_droq.c | 4 -
.../net/ethernet/cavium/liquidio/request_manager.c | 1 -
drivers/net/ethernet/intel/e1000/e1000_main.c | 5 -
drivers/net/ethernet/intel/e1000e/netdev.c | 7 -
drivers/net/ethernet/intel/fm10k/fm10k_iov.c | 2 -
drivers/net/ethernet/intel/fm10k/fm10k_main.c | 5 -
drivers/net/ethernet/intel/i40e/i40e_txrx.c | 5 -
drivers/net/ethernet/intel/iavf/iavf_txrx.c | 5 -
drivers/net/ethernet/intel/ice/ice_txrx.c | 5 -
drivers/net/ethernet/intel/igb/igb_main.c | 5 -
drivers/net/ethernet/intel/igbvf/netdev.c | 4 -
drivers/net/ethernet/intel/igc/igc_main.c | 5 -
drivers/net/ethernet/intel/ixgbe/ixgbe_main.c | 5 -
drivers/net/ethernet/marvell/sky2.c | 4 -
drivers/net/ethernet/mellanox/mlx4/catas.c | 4 -
drivers/net/ethernet/mellanox/mlx4/cmd.c | 13 --
drivers/net/ethernet/mellanox/mlx5/core/cmd.c | 1 -
drivers/net/ethernet/myricom/myri10ge/myri10ge.c | 2 -
drivers/net/ethernet/neterion/s2io.c | 2 -
drivers/net/ethernet/neterion/vxge/vxge-main.c | 5 -
drivers/net/ethernet/neterion/vxge/vxge-traffic.c | 4 -
drivers/net/ethernet/qlogic/qed/qed_int.c | 13 --
drivers/net/ethernet/qlogic/qed/qed_spq.c | 3 -
drivers/net/ethernet/qlogic/qede/qede_ethtool.c | 8 -
drivers/net/ethernet/qlogic/qede/qede_fp.c | 8 -
drivers/net/ethernet/qlogic/qla3xxx.c | 1 -
drivers/net/ethernet/qlogic/qlge/qlge.h | 1 -
drivers/net/ethernet/qlogic/qlge/qlge_main.c | 1 -
drivers/net/ethernet/renesas/ravb_main.c | 9 -
drivers/net/ethernet/renesas/ravb_ptp.c | 3 -
drivers/net/ethernet/renesas/sh_eth.c | 1 -
drivers/net/ethernet/sfc/falcon/io.h | 2 -
drivers/net/ethernet/sfc/io.h | 2 -
drivers/net/ethernet/silan/sc92031.c | 15 --
drivers/net/ethernet/via/via-rhine.c | 3 -
drivers/net/ethernet/wiznet/w5100.c | 6 -
drivers/net/ethernet/wiznet/w5300.c | 15 --
drivers/net/wireless/ath/ath5k/base.c | 4 -
drivers/net/wireless/ath/ath5k/mac80211-ops.c | 2 -
drivers/net/wireless/broadcom/b43/main.c | 7 -
drivers/net/wireless/broadcom/b43/sysfs.c | 1 -
drivers/net/wireless/broadcom/b43legacy/ilt.c | 2 -
drivers/net/wireless/broadcom/b43legacy/main.c | 20 --
drivers/net/wireless/broadcom/b43legacy/phy.c | 1 -
drivers/net/wireless/broadcom/b43legacy/pio.h | 1 -
drivers/net/wireless/broadcom/b43legacy/radio.c | 4 -
drivers/net/wireless/broadcom/b43legacy/sysfs.c | 1 -
drivers/net/wireless/intel/iwlegacy/common.h | 7 -
drivers/net/wireless/intel/iwlwifi/pcie/trans.c | 1 -
drivers/ntb/hw/idt/ntb_hw_idt.c | 7 -
drivers/ntb/test/ntb_perf.c | 3 -
drivers/scsi/bfa/bfa.h | 3 +-
drivers/scsi/bfa/bfa_hw_cb.c | 2 -
drivers/scsi/bfa/bfa_hw_ct.c | 2 -
drivers/scsi/bnx2fc/bnx2fc_hwi.c | 2 -
drivers/scsi/bnx2i/bnx2i_hwi.c | 3 -
drivers/scsi/megaraid/megaraid_sas_base.c | 1 -
drivers/scsi/megaraid/megaraid_sas_fusion.c | 1 -
drivers/scsi/mpt3sas/mpt3sas_base.c | 1 -
drivers/scsi/qedf/qedf_io.c | 1 -
drivers/scsi/qedi/qedi_fw.c | 1 -
drivers/scsi/qla1280.c | 15 --
drivers/ssb/pci.c | 1 -
drivers/ssb/pcmcia.c | 4 -
drivers/staging/comedi/drivers/mite.c | 3 -
drivers/staging/comedi/drivers/ni_660x.c | 2 -
drivers/staging/comedi/drivers/ni_mio_common.c | 1 -
drivers/staging/comedi/drivers/ni_pcidio.c | 2 -
drivers/staging/comedi/drivers/ni_tio.c | 1 -
drivers/staging/comedi/drivers/s626.c | 2 -
drivers/tty/serial/men_z135_uart.c | 1 -
drivers/tty/serial/serial_txx9.c | 1 -
drivers/usb/early/xhci-dbc.c | 4 -
drivers/usb/host/xhci-dbgcap.c | 2 -
include/asm-generic/io.h | 7 +-
include/asm-generic/mmiowb.h | 63 ++++++
include/asm-generic/mmiowb_types.h | 12 ++
include/linux/qed/qed_if.h | 2 -
include/linux/spinlock.h | 11 +-
kernel/Kconfig.locks | 7 +
kernel/locking/spinlock.c | 7 +
kernel/locking/spinlock_debug.c | 6 +-
sound/soc/txx9/txx9aclc-ac97.c | 1 -
181 files changed, 314 insertions(+), 820 deletions(-)
create mode 100644 arch/ia64/include/asm/mmiowb.h
create mode 100644 arch/mips/include/asm/mmiowb.h
create mode 100644 arch/powerpc/include/asm/mmiowb.h
create mode 100644 arch/riscv/include/asm/mmiowb.h
create mode 100644 arch/sh/include/asm/mmiowb.h
create mode 100644 include/asm-generic/mmiowb.h
create mode 100644 include/asm-generic/mmiowb_types.h

--
2.11.0