| Message ID | 20230314121216.413434-1-schnelle@linux.ibm.com (mailing list archive) |
|---|---|
| Headers | show |
| Series | Kconfig: Introduce HAS_IOPORT config option | expand |
On Tue, Mar 14, 2023, at 13:11, Niklas Schnelle wrote: > Hello Kernel Hackers, > > Some platforms such as s390 do not support PCI I/O spaces. On such platforms > I/O space accessors like inb()/outb() are stubs that can never actually work. > The way these stubs are implemented in asm-generic/io.h leads to compiler > warnings because any use will be a NULL pointer access on these platforms. In > a previous patch we tried handling this with a run-time warning on access. This > approach however was rejected by Linus[0] with the argument that this really > should be a compile-time check and, though a much more invasive change, we > believe that is indeed the right approach. > > This patch series aims to do exactly that by introducing a HAS_IOPORT config > option akin to the existing HAS_IOMEM. When this is unset inb()/outb() and > friends may not be defined. This is also the same approach originally planned by > Uwe Kleine-König as mentioned in commit ce816fa88cca ("Kconfig: rename > HAS_IOPORT to HAS_IOPORT_MAP"). > > This series builds heavily on an original patch for demonstating the concept by > Arnd Bergmann[1] and incoporates feedback of previous RFC versions [2] and [3]. > > This version is based on v6.3-rc1 and is also available on my kernel.org tree > in the has_ioport_v3 branch with the PGP signed tag has_ioport_v3_signed: > > https://git.kernel.org/pub/scm/linux/kernel/git/niks/linux.git Thanks a lot for the rebase, hopefully we can finally get this merged. I'll go through all patches and note everything I spot that should be improved. I'd like to make sure that at least the first patch can get merged quickly so we can continue on the rest. Since this is all related to asm-generic/io.h and cross-architecture work, I can pick up anything that has nobody else maintaining it through the asm-generic tree. Arnd
Hello Kernel Hackers, Some platforms such as s390 do not support PCI I/O spaces. On such platforms I/O space accessors like inb()/outb() are stubs that can never actually work. The way these stubs are implemented in asm-generic/io.h leads to compiler warnings because any use will be a NULL pointer access on these platforms. In a previous patch we tried handling this with a run-time warning on access. This approach however was rejected by Linus[0] with the argument that this really should be a compile-time check and, though a much more invasive change, we believe that is indeed the right approach. This patch series aims to do exactly that by introducing a HAS_IOPORT config option akin to the existing HAS_IOMEM. When this is unset inb()/outb() and friends may not be defined. This is also the same approach originally planned by Uwe Kleine-König as mentioned in commit ce816fa88cca ("Kconfig: rename HAS_IOPORT to HAS_IOPORT_MAP"). This series builds heavily on an original patch for demonstating the concept by Arnd Bergmann[1] and incoporates feedback of previous RFC versions [2] and [3]. This version is based on v6.3-rc1 and is also available on my kernel.org tree in the has_ioport_v3 branch with the PGP signed tag has_ioport_v3_signed: https://git.kernel.org/pub/scm/linux/kernel/git/niks/linux.git Thanks, Niklas Schnelle Changes from RFC v2: - Rebased on v6.3-rc1 - Fixed a NULL pointer dereference in set_io_from_upio() due to accidentially expanded #ifdef CONFIG_SERIAL_8250_RT288X (kernel test robot) - Dropped "ACPI: add dependency on HAS_IOPORT" (Bjorn Helgaas) - Reworded commit message and moved ifdefs for "PCI/sysfs: Make I/O resource depend on HAS_IOPORT" (Bjorn Helgaas) - Instead of complete removal inb() etc. are marked with __compiletime_error() when HAS_IOPORT is unset allowing for better error reporting (Ahmad Fatoum) - Removed HAS_IOPORT dependency from PCMCIA as I/O port use is optional in at least PC Card. Instead added HAS_IOPORT on a per driver basis. (Bjorn Helgaas) - Made uhci_has_pci_registers() constant 0 if HAS_IOPORT is not defined (Alan Stern) Changes from RFC v1: - Completely dropped the LEGACY_PCI option and replaced its dependencies with HAS_IOPORT as appropriate - In the usb subsystem patch I incorporated the feedback from v1 by Alan Stern: - Used a local macro to nop in*()/out*() in the helpers - Removed an unnecessary further restriction on CONFIG_USB_UHCI_HCD - Added a few more subsystems including wireless, ptp, and, mISDN that I had previously missed due to a blanket !S390. - Removed blanket !S390 dependencies where they are added due to the I/O port problem - In the sound system SND_OPL3_LIB needed to use "depends on" instead of "select" because of its added HAS_IOPORT dependency - In the drm subsystem the bochs driver gets #ifdefs instead of a blanket dependency because its MMIO capable device variant should work without HAS_IOPORT. [0] https://lore.kernel.org/lkml/CAHk-=wg80je=K7madF4e7WrRNp37e3qh6y10Svhdc7O8SZ_-8g@mail.gmail.com/ [1] https://lore.kernel.org/lkml/CAK8P3a0MNbx-iuzW_-=0ab6-TTZzwV-PT_6gAC1Gp5PgYyHcrA@mail.gmail.com/ [2] https://yhbt.net/lore/all/20211227164317.4146918-1-schnelle@linux.ibm.com/ [3] https://lore.kernel.org/all/20220429135108.2781579-1-schnelle@linux.ibm.com/ Niklas Schnelle (38): Kconfig: introduce HAS_IOPORT option and select it as necessary ata: add HAS_IOPORT dependencies char: impi, tpm: depend on HAS_IOPORT comedi: add HAS_IOPORT dependencies counter: add HAS_IOPORT dependencies /dev/port: don't compile file operations without CONFIG_DEVPORT drm: handle HAS_IOPORT dependencies firmware: dmi-sysfs: handle HAS_IOPORT=n gpio: add HAS_IOPORT dependencies hwmon: add HAS_IOPORT dependencies i2c: add HAS_IOPORT dependencies iio: ad7606: Kconfig: add HAS_IOPORT dependencies Input: add HAS_IOPORT dependencies Input: gameport: add ISA and HAS_IOPORT dependencies leds: add HAS_IOPORT dependencies media: add HAS_IOPORT dependencies misc: add HAS_IOPORT dependencies mISDN: add HAS_IOPORT dependencies mpt fusion: add HAS_IOPORT dependencies net: handle HAS_IOPORT dependencies parport: PC style parport depends on HAS_IOPORT PCI: Make quirk using inw() depend on HAS_IOPORT PCI/sysfs: Make I/O resource depend on HAS_IOPORT pcmcia: add HAS_IOPORT dependencies platform: add HAS_IOPORT dependencies pnp: add HAS_IOPORT dependencies power: add HAS_IOPORT dependencies rtc: add HAS_IOPORT dependencies scsi: add HAS_IOPORT dependencies sound: add HAS_IOPORT dependencies speakup: add HAS_IOPORT dependency for SPEAKUP_SERIALIO staging: add HAS_IOPORT dependencies tty: serial: handle HAS_IOPORT dependencies usb: handle HAS_IOPORT dependencies video: handle HAS_IOPORT dependencies watchdog: add HAS_IOPORT dependencies wireless: add HAS_IOPORT dependencies asm-generic/io.h: drop inb() etc for HAS_IOPORT=n arch/alpha/Kconfig | 1 + arch/arm/Kconfig | 1 + arch/arm64/Kconfig | 1 + arch/ia64/Kconfig | 1 + arch/m68k/Kconfig | 1 + arch/microblaze/Kconfig | 1 + arch/mips/Kconfig | 2 + arch/parisc/Kconfig | 2 + arch/powerpc/Kconfig | 2 +- arch/riscv/Kconfig | 1 + arch/sh/Kconfig | 1 + arch/sparc/Kconfig | 1 + arch/um/Kconfig | 1 + arch/x86/Kconfig | 2 + drivers/accessibility/speakup/Kconfig | 1 + drivers/ata/Kconfig | 1 + drivers/bus/Kconfig | 2 +- drivers/char/Kconfig | 3 +- drivers/char/ipmi/Makefile | 11 +- drivers/char/ipmi/ipmi_si_intf.c | 3 +- drivers/char/ipmi/ipmi_si_pci.c | 3 + drivers/char/mem.c | 6 +- drivers/char/pcmcia/Kconfig | 8 +- drivers/char/tpm/Kconfig | 1 + drivers/char/tpm/tpm_infineon.c | 14 ++- drivers/char/tpm/tpm_tis_core.c | 19 ++- drivers/comedi/Kconfig | 103 +++++++++------ drivers/counter/Kconfig | 1 + drivers/eisa/Kconfig | 1 + drivers/firmware/dmi-sysfs.c | 4 + drivers/gpio/Kconfig | 2 +- drivers/gpu/drm/qxl/Kconfig | 1 + drivers/gpu/drm/tiny/bochs.c | 19 +++ drivers/gpu/drm/tiny/cirrus.c | 2 + drivers/hwmon/Kconfig | 21 +++- drivers/i2c/busses/Kconfig | 31 ++--- drivers/iio/adc/Kconfig | 2 +- drivers/input/gameport/Kconfig | 4 +- drivers/input/serio/Kconfig | 2 + drivers/input/touchscreen/Kconfig | 1 + drivers/isdn/Kconfig | 1 - drivers/isdn/hardware/mISDN/Kconfig | 12 +- drivers/leds/Kconfig | 2 +- drivers/media/pci/dm1105/Kconfig | 2 +- drivers/media/radio/Kconfig | 14 ++- drivers/media/rc/Kconfig | 6 + drivers/message/fusion/Kconfig | 2 +- drivers/misc/altera-stapl/Makefile | 3 +- drivers/misc/altera-stapl/altera.c | 6 +- drivers/net/Kconfig | 2 +- drivers/net/arcnet/Kconfig | 2 +- drivers/net/can/cc770/Kconfig | 1 + drivers/net/can/sja1000/Kconfig | 1 + drivers/net/ethernet/3com/Kconfig | 4 +- drivers/net/ethernet/8390/Kconfig | 6 +- drivers/net/ethernet/amd/Kconfig | 4 +- drivers/net/ethernet/fujitsu/Kconfig | 2 +- drivers/net/ethernet/intel/Kconfig | 2 +- drivers/net/ethernet/sis/Kconfig | 4 +- drivers/net/ethernet/smsc/Kconfig | 2 +- drivers/net/ethernet/ti/Kconfig | 2 +- drivers/net/ethernet/via/Kconfig | 1 + drivers/net/ethernet/xircom/Kconfig | 2 +- drivers/net/fddi/Kconfig | 2 +- drivers/net/fddi/defxx.c | 2 +- drivers/net/hamradio/Kconfig | 6 +- drivers/net/wan/Kconfig | 2 +- drivers/net/wireless/atmel/Kconfig | 2 +- drivers/net/wireless/intersil/hostap/Kconfig | 2 +- drivers/parport/Kconfig | 4 +- drivers/pci/pci-sysfs.c | 4 + drivers/pci/quirks.c | 2 + drivers/pcmcia/Kconfig | 5 +- drivers/platform/chrome/Kconfig | 1 + drivers/platform/chrome/wilco_ec/Kconfig | 1 + drivers/pnp/isapnp/Kconfig | 2 +- drivers/power/reset/Kconfig | 1 + drivers/rtc/Kconfig | 4 +- drivers/scsi/Kconfig | 25 ++-- drivers/scsi/aic7xxx/Kconfig.aic79xx | 2 +- drivers/scsi/aic7xxx/Kconfig.aic7xxx | 2 +- drivers/scsi/aic94xx/Kconfig | 2 +- drivers/scsi/megaraid/Kconfig.megaraid | 6 +- drivers/scsi/mvsas/Kconfig | 2 +- drivers/scsi/pcmcia/Kconfig | 6 +- drivers/scsi/qla2xxx/Kconfig | 2 +- drivers/staging/sm750fb/Kconfig | 2 +- drivers/staging/vt6655/Kconfig | 2 +- drivers/tty/Kconfig | 2 +- drivers/tty/serial/8250/8250_early.c | 4 + drivers/tty/serial/8250/8250_pci.c | 14 +++ drivers/tty/serial/8250/8250_port.c | 44 +++++-- drivers/tty/serial/8250/Kconfig | 5 +- drivers/tty/serial/Kconfig | 2 +- drivers/usb/core/hcd-pci.c | 2 + drivers/usb/host/Kconfig | 4 +- drivers/usb/host/pci-quirks.c | 125 ++++++++++--------- drivers/usb/host/pci-quirks.h | 31 +++-- drivers/usb/host/uhci-hcd.c | 2 +- drivers/usb/host/uhci-hcd.h | 36 ++++-- drivers/video/console/Kconfig | 1 + drivers/video/fbdev/Kconfig | 25 ++-- drivers/watchdog/Kconfig | 6 +- include/asm-generic/io.h | 60 +++++++++ include/linux/gameport.h | 9 +- include/linux/parport.h | 2 +- include/video/vga.h | 8 ++ lib/Kconfig | 4 + lib/Kconfig.kgdb | 3 +- net/ax25/Kconfig | 2 +- sound/drivers/Kconfig | 3 + sound/isa/Kconfig | 31 ++++- sound/pci/Kconfig | 45 +++++-- sound/pcmcia/Kconfig | 2 + 114 files changed, 649 insertions(+), 281 deletions(-) base-commit: eeac8ede17557680855031c6f305ece2378af326