On Tue, 19 Jul 2016 09:01:40 -0400 Sinan Kaya <okaya@xxxxxxxxxxxxxx> wrote: > The current code only supports the device tree based platforms. > The code checks for the presence of a reset driver and calls the reset > function pointer by looking up the reset driver as a module. > > ACPI defines _RST method to perform device level reset. After the _RST > method is executed, the OS can resume using the device. > > The patchset is moving the device tree specific pieces out of the code > to common functions so that ACPI support is added without impacting the > rest of the code. > > During probe, the ACPI HID of the object will be saved and will be used to > determine if this is an ACPI capable platform or not. If acpihid is NULL > then, device tree functions are called. > > In addition to plumbing ACPI support, reset functionality is now a > requirement by default. > > The code was allowing platform devices to be used without a supporting > VFIO reset driver. The hardware can be left in some inconsistent state > after a guest machine abort. > > The reset driver will put the hardware back to safe state and disable > interrupts before returning the control back to the host machine. > > Adding a new reset_required kernel module option to platform > VFIO drivers with a default value of true. > > New requirements are: > 1. A reset function needs to be implemented by the corresponding driver > via DT/ACPI. > 2. The reset function needs to be discovered via DT/ACPI. > > The probe of the driver will fail if any of the above conditions are > not satisfied. > > Changes from V10: > 1. Get rid of redundant if check in the acpi_probe since we are now using > WARN_ON. > 2. Change the error code order according to Alex's recommendation. > > Sinan Kaya (9): > vfio: platform: rename reset function > vfio: platform: move reset call to a common function > vfio: platform: determine reset capability > vfio: platform: add support for ACPI probe > vfio: platform: add extra debug info argument to call reset > vfio: platform: call _RST method when using ACPI > vfio, platform: make reset driver a requirement by default > vfio: platform: check reset call return code during open > vfio: platform: check reset call return code during release > > drivers/vfio/platform/vfio_amba.c | 1 + > drivers/vfio/platform/vfio_platform.c | 5 + > drivers/vfio/platform/vfio_platform_common.c | 192 +++++++++++++++++++++----- > drivers/vfio/platform/vfio_platform_private.h | 9 +- > 4 files changed, 173 insertions(+), 34 deletions(-) > Applied to next branch for v4.8. Thanks, Alex -- To unsubscribe from this list: send the line "unsubscribe linux-arm-msm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
