On Thu, Feb 28, 2019 at 02:59:17PM +0100, Ulf Hansson wrote: > Instead of iterating through all the state nodes in DT, to find out how > many states that needs to be allocated, let's use the number already known > by the cpuidle driver. In this way we can drop the iteration altogether. > > Signed-off-by: Ulf Hansson <ulf.hans...@linaro.org> > --- > drivers/firmware/psci/psci.c | 25 ++++++++++++------------- > 1 file changed, 12 insertions(+), 13 deletions(-) > > diff --git a/drivers/firmware/psci/psci.c b/drivers/firmware/psci/psci.c > index d50b46a0528f..cbfc936d251c 100644 > --- a/drivers/firmware/psci/psci.c > +++ b/drivers/firmware/psci/psci.c > @@ -290,26 +290,20 @@ static int psci_dt_parse_state_node(struct device_node > *np, u32 *state) > static int psci_dt_cpu_init_idle(struct cpuidle_driver *drv, > struct device_node *cpu_node, int cpu) > { > - int i, ret = 0, count = 0; > + int i, ret = 0, num_state_nodes = drv->state_count - 1; > u32 *psci_states; > struct device_node *state_node; > > - /* Count idle states */ > - while ((state_node = of_parse_phandle(cpu_node, "cpu-idle-states", > - count))) { > - count++; > - of_node_put(state_node); > - } > -
To be honest, I'd rather not tighten the coupling with the cpuidle driver here. For example, I'm not that happy with the PSCI backend having to know the driver has a specific WFI state. IIUC we could get rid of the explicit counting with something like: count = of_parse_phandle_with_args(cpu_node, "cpu-idle-states", NULL); ... but I'm not sure that the overall change is a simplification. Does this change make it easier to plumb in something in future? Thanks, Mark. > - if (!count) > - return -ENODEV; > - > - psci_states = kcalloc(count, sizeof(*psci_states), GFP_KERNEL); > + psci_states = kcalloc(num_state_nodes, sizeof(*psci_states), > + GFP_KERNEL); > if (!psci_states) > return -ENOMEM; > > - for (i = 0; i < count; i++) { > + for (i = 0; i < num_state_nodes; i++) { > state_node = of_parse_phandle(cpu_node, "cpu-idle-states", i); > + if (!state_node) > + break; > + > ret = psci_dt_parse_state_node(state_node, &psci_states[i]); > of_node_put(state_node); > > @@ -319,6 +313,11 @@ static int psci_dt_cpu_init_idle(struct cpuidle_driver > *drv, > pr_debug("psci-power-state %#x index %d\n", psci_states[i], i); > } > > + if (i != num_state_nodes) { > + ret = -ENODEV; > + goto free_mem; > + } > + > /* Idle states parsed correctly, initialize per-cpu pointer */ > per_cpu(psci_power_state, cpu) = psci_states; > return 0; > -- > 2.17.1 >