Hi all,
This patch series implements generic reset controller support for
vfio-platform, for devices that are connected to an SoC-internal reset
controller and can be reset in a generic way. This avoids having to
write/change a vfio-specific reset driver for each and every device to be
passed-through to a guest.
It consists of two patches:
- The first patch enhances the reset controller subsystem to add support
for dedicated resets.
This addresses the issue that even reset_control_get_exclusive() does
not guarantee that we have an exclusive wire between the device and
the reset controller.
- The second patch enhances vfio-platform to add generic reset controller
support.
Changes compared to v3:
- Add Reviewed-by,
- New patch "reset: Add support for dedicated reset controls",
- Use new RFC reset_control_get_dedicated() instead of
of_reset_control_get_exclusive(), to (a) make it more generic, and
(b) make sure the reset returned is really a dedicated reset, and
does not affect other devices,
- Drop vfio-platform reset leak fix, which has been applied.
Changes compared to v2:
- Add Reviewed-by,
- Merge similar checks in vfio_platform_has_reset().
Changes compared to v1:
- Add Reviewed-by,
- Don't store error values in vdev->reset_control,
- Use of_reset_control_get_exclusive() instead of
__of_reset_control_get(),
- Improve description.
This has been tested on R-Car H3/Salvator-XS:
- SATA can be exported, as it has a dedicated reset,
- PWM1 cannot, as its reset is shared with all other PWM modules:
"VFIO: No reset function found for device e6e31000.pwm".
Thanks for your comments!
Geert Uytterhoeven (2):
[RFC] reset: Add support for dedicated reset controls
[RFC] vfio: platform: Add generic reset controller support
drivers/reset/core.c | 76 ++++++++++++++++---
drivers/vfio/platform/vfio_platform_common.c | 20 ++++-
drivers/vfio/platform/vfio_platform_private.h | 1 +
include/linux/reset.h | 60 ++++++++++-----
4 files changed, 126 insertions(+), 31 deletions(-)
--
2.17.1
Gr{oetje,eeting}s,
Geert
--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@xxxxxxxxxxxxxx
In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds
