[PATCH v6 20/25] drivers: firmware: psci: Introduce psci_dt_topology_init()
From: mark.rutland@arm.com (Mark Rutland)
Date: 2018-03-14 17:38:41
Also in:
linux-arm-msm, linux-pm, lkml
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.
quoted hunk ↗ jump to hunk
Cc: Lina Iyer <redacted> Co-developed-by: Lina Iyer <redacted> Signed-off-by: Ulf Hansson <redacted> --- 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.