Hi Sinan, On 20/06/2016 17:51, Sinan Kaya 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 AMBA and 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 V7: > 1. Move the reset function test before IOMMU group set up so that we can > clean up properly when reset function is not found. > 2. Correct the _RST function call. _RST method does not return any value. > We were calling acpi_evaluate_integer. The correct API needs to be > acpi_evaluate_object. > > 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 | 5 + > drivers/vfio/platform/vfio_platform.c | 5 + > drivers/vfio/platform/vfio_platform_common.c | 197 +++++++++++++++++++++----- > drivers/vfio/platform/vfio_platform_private.h | 8 +- > 4 files changed, 177 insertions(+), 38 deletions(-) > I tested with device tree and I did not find any issue: Tested-by: Eric Auger <eric.auger@xxxxxxxxxx> For the whole series: Reviewed-by: Eric Auger <eric.auger@xxxxxxxxxx> Please note this will collide with "[PATCH V3] vfio: platform: support No-IOMMU mode" (s/iommu_group_put/vfio_iommu_group_put) Best Regards Eric -- To unsubscribe from this list: send the line "unsubscribe linux-acpi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
