On Wed, Mar 14, 2018 at 05:58:30PM +0100, Ulf Hansson wrote: > In case the hierarchical layout is used in DT, we want to initialize the > corresponding PM domain topology for the CPUs, by using the generic PM > domain (aka genpd) infrastructure. > > At first glance, it may seem feasible to hook into the existing > psci_dt_init() function, although because it's called quite early in the > boot sequence, allocating the dynamic data structure for a genpd doesn't > work. > > Therefore, let's export a new init function for PSCI, > psci_dt_topology_init(), which the ARM machine code should call from a > suitable initcall. > > Succeeding to initialize the PM domain topology, which means at least one > instance of a genpd becomes created, allows us to continue to enable the > PSCI OS initiated mode for the platform. If everything turns out fine, > let's print a message in log to inform the user about the changed mode. > > In case of any failures, we stick to the default PSCI Platform Coordinated > mode.
For kexec/kdump we'll need to explicitly set the suspend mode to platform coordinated if for whatever reason we choose not to use OSI. > > Cc: Lina Iyer <[email protected]> > Co-developed-by: Lina Iyer <[email protected]> > Signed-off-by: Ulf Hansson <[email protected]> > --- > drivers/firmware/psci.c | 31 +++++++++++++++++++++++++++++++ > include/linux/psci.h | 2 ++ > 2 files changed, 33 insertions(+) > > diff --git a/drivers/firmware/psci.c b/drivers/firmware/psci.c > index 463f78c..45d55fc 100644 > --- a/drivers/firmware/psci.c > +++ b/drivers/firmware/psci.c > @@ -723,6 +723,37 @@ int __init psci_dt_init(void) > return ret; > } > > +int __init psci_dt_topology_init(void) > +{ > + struct device_node *np; > + int ret; > + > + if (!psci_has_osi_support()) > + return 0; > + > + np = of_find_matching_node_and_match(NULL, psci_of_match, NULL); > + if (!np) > + return -ENODEV; > + > + /* Initialize the CPU PM domains based on topology described in DT. */ > + ret = psci_dt_init_pm_domains(np); > + if (ret <= 0) > + goto out; > + > + /* Enable OSI mode. */ > + ret = invoke_psci_fn(PSCI_1_0_FN_SET_SUSPEND_MODE, > + PSCI_1_0_SUSPEND_MODE_OSI, 0, 0); IIUC, this patch will need to be moved after the subsequent two patches to ensure that this series bisects cleanly. Thanks, Mark.
