On Thu, Nov 26, 2020 at 03:54:00PM +0000, David Brazdil wrote:
> Function IDs used by PSCI are configurable for v0.1 via DT/APCI. If the
> host is using PSCI v0.1, KVM's host PSCI proxy needs to use the same IDs.
> Expose the array holding the information with a read-only accessor.
>
> Signed-off-by: David Brazdil <dbrazdil@xxxxxxxxxx>
> ---
> drivers/firmware/psci/psci.c | 16 ++++++++--------
> include/linux/psci.h | 10 ++++++++++
> 2 files changed, 18 insertions(+), 8 deletions(-)
>
> diff --git a/drivers/firmware/psci/psci.c b/drivers/firmware/psci/psci.c
> index 213c68418a65..40609564595e 100644
> --- a/drivers/firmware/psci/psci.c
> +++ b/drivers/firmware/psci/psci.c
> @@ -58,16 +58,16 @@ typedef unsigned long (psci_fn)(unsigned long, unsigned long,
> unsigned long, unsigned long);
> static psci_fn *invoke_psci_fn;
>
> -enum psci_function {
> - PSCI_FN_CPU_SUSPEND,
> - PSCI_FN_CPU_ON,
> - PSCI_FN_CPU_OFF,
> - PSCI_FN_MIGRATE,
> - PSCI_FN_MAX,
> -};
> -
> static u32 psci_function_id[PSCI_FN_MAX];
>
> +u32 psci_get_function_id(enum psci_function fn)
> +{
> + if (WARN_ON_ONCE(fn < 0 || fn >= PSCI_FN_MAX))
> + return 0;
> +
> + return psci_function_id[fn];
> +}
I'd really like if we could namespace this with a psci_0_1_* prefix
before we expose it outside of the PSCI code. I appreciate that's a
larger change, but I reckon we only need a couple of new patches:
1) Split the ops which consume the FN ids into separate psci_0_1_*() and
psci_0_2_*() variants, with a common __psci_*() helper that takes the
function ID as an argument. The 0_1 variants would read the function
ID from a variable, and the 0_2 variants would hard-code the id.
2) Replace the psci_function_id array with:
struct psci_0_1_function_ids {
u32 suspend;
u32 cpu_on;
u32 cpu_off;
u32 migrate;
};
... and remove enum psci_function entirely.
3) Add a helper which returns the entire psci_0_1_function_ids struct in
one go. No warnings necessary.
Does that sound OK to you?
Thanks,
Mark.
> +
> #define PSCI_0_2_POWER_STATE_MASK \
> (PSCI_0_2_POWER_STATE_ID_MASK | \
> PSCI_0_2_POWER_STATE_TYPE_MASK | \
> diff --git a/include/linux/psci.h b/include/linux/psci.h
> index 2a1bfb890e58..5b49a5c82d6f 100644
> --- a/include/linux/psci.h
> +++ b/include/linux/psci.h
> @@ -21,6 +21,16 @@ bool psci_power_state_is_valid(u32 state);
> int psci_set_osi_mode(bool enable);
> bool psci_has_osi_support(void);
>
> +enum psci_function {
> + PSCI_FN_CPU_SUSPEND,
> + PSCI_FN_CPU_ON,
> + PSCI_FN_CPU_OFF,
> + PSCI_FN_MIGRATE,
> + PSCI_FN_MAX,
> +};
> +
> +u32 psci_get_function_id(enum psci_function fn);
> +
> struct psci_operations {
> u32 (*get_version)(void);
> int (*cpu_suspend)(u32 state, unsigned long entry_point);
> --
> 2.29.2.454.gaff20da3a2-goog
>
