Currently, a persistent memory device's mode must be coordinated with the driver to which it needs to bind. To change it from the fsdax to the device-dax driver, you first change the mode of the device itself.
Instead of adding a new device mode, allow the PMEM mode to also bind to the KMEM driver. As I write this, I'm realizing that it might have just been better to add a new device mode, rather than hijacking the PMEM eode. If this is the case, please speak up, NVDIMM folks. :) Cc: Dan Williams <[email protected]> Cc: Dave Jiang <[email protected]> Cc: Ross Zwisler <[email protected]> Cc: Vishal Verma <[email protected]> Cc: Tom Lendacky <[email protected]> Cc: Andrew Morton <[email protected]> Cc: Michal Hocko <[email protected]> Cc: [email protected] Cc: [email protected] Cc: [email protected] Cc: Huang Ying <[email protected]> Cc: Fengguang Wu <[email protected]> --- b/drivers/nvdimm/bus.c | 15 ++++++++++++++- 1 file changed, 14 insertions(+), 1 deletion(-) diff -puN drivers/nvdimm/bus.c~dax-kmem-try-again-2018-3-bus-match-override drivers/nvdimm/bus.c --- a/drivers/nvdimm/bus.c~dax-kmem-try-again-2018-3-bus-match-override 2018-10-22 13:12:22.522930391 -0700 +++ b/drivers/nvdimm/bus.c 2018-10-22 13:12:22.525930391 -0700 @@ -464,11 +464,24 @@ static struct nd_device_driver nd_bus_dr static int nvdimm_bus_match(struct device *dev, struct device_driver *drv) { struct nd_device_driver *nd_drv = to_nd_device_driver(drv); + bool match; if (is_nvdimm_bus(dev) && nd_drv == &nd_bus_driver) return true; - return !!test_bit(to_nd_device_type(dev), &nd_drv->type); + match = !!test_bit(to_nd_device_type(dev), &nd_drv->type); + + /* + * We allow PMEM devices to be bound to the KMEM driver. + * Force a match if we detect a PMEM device type but + * a KMEM device driver. + */ + if (!match && + (to_nd_device_type(dev) == ND_DEVICE_DAX_PMEM) && + (nd_drv->type == ND_DRIVER_DAX_KMEM)) + match = true; + + return match; } static ASYNC_DOMAIN_EXCLUSIVE(nd_async_domain); _ _______________________________________________ Linux-nvdimm mailing list [email protected] https://lists.01.org/mailman/listinfo/linux-nvdimm
