On Fri, Apr 09, 2021 at 10:46:33AM -0700, Nikos Nikoleris wrote:
> On 07/04/2021 19:59, Andrew Jones wrote:
> > The method can also be smc and it will be when running on bare metal.
> >
> > Signed-off-by: Andrew Jones <drjones@xxxxxxxxxx>
> > ---
> > arm/selftest.c | 34 +++++++---------------------------
> > lib/arm/asm/psci.h | 9 +++++++--
> > lib/arm/psci.c | 17 +++++++++++++++--
> > lib/arm/setup.c | 22 ++++++++++++++++++++++
> > 4 files changed, 51 insertions(+), 31 deletions(-)
> >
> > diff --git a/arm/selftest.c b/arm/selftest.c
> > index 4495b161cdd5..9f459ed3d571 100644
> > --- a/arm/selftest.c
> > +++ b/arm/selftest.c
> > @@ -400,33 +400,13 @@ static void check_vectors(void *arg __unused)
> > exit(report_summary());
> > }
> > -static bool psci_check(void)
> > +static void psci_print(void)
> > {
> > - const struct fdt_property *method;
> > - int node, len, ver;
> > -
> > - node = fdt_node_offset_by_compatible(dt_fdt(), -1, "arm,psci-0.2");
> > - if (node < 0) {
> > - printf("PSCI v0.2 compatibility required\n");
> > - return false;
> > - }
> > -
> > - method = fdt_get_property(dt_fdt(), node, "method", &len);
> > - if (method == NULL) {
> > - printf("bad psci device tree node\n");
> > - return false;
> > - }
> > -
> > - if (len < 4 || strcmp(method->data, "hvc") != 0) {
> > - printf("psci method must be hvc\n");
> > - return false;
> > - }
> > -
> > - ver = psci_invoke(PSCI_0_2_FN_PSCI_VERSION, 0, 0, 0);
> > - printf("PSCI version %d.%d\n", PSCI_VERSION_MAJOR(ver),
> > - PSCI_VERSION_MINOR(ver));
> > -
> > - return true;
> > + int ver = psci_invoke(PSCI_0_2_FN_PSCI_VERSION, 0, 0, 0);
> > + report_info("PSCI version: %d.%d", PSCI_VERSION_MAJOR(ver),
> > + PSCI_VERSION_MINOR(ver));
> > + report_info("PSCI method: %s", psci_invoke == psci_invoke_hvc ?
> > + "hvc" : "smc");
> > }
> > static void cpu_report(void *data __unused)
> > @@ -465,7 +445,7 @@ int main(int argc, char **argv)
> > } else if (strcmp(argv[1], "smp") == 0) {
> > - report(psci_check(), "PSCI version");
> > + psci_print();
> > on_cpus(cpu_report, NULL);
> > while (!cpumask_full(&ready))
> > cpu_relax();
> > diff --git a/lib/arm/asm/psci.h b/lib/arm/asm/psci.h
> > index 7b956bf5987d..e385ce27f5d1 100644
> > --- a/lib/arm/asm/psci.h
> > +++ b/lib/arm/asm/psci.h
> > @@ -3,8 +3,13 @@
> > #include <libcflat.h>
> > #include <linux/psci.h>
> > -extern int psci_invoke(unsigned long function_id, unsigned long arg0,
> > - unsigned long arg1, unsigned long arg2);
> > +typedef int (*psci_invoke_fn)(unsigned long function_id, unsigned long arg0,
> > + unsigned long arg1, unsigned long arg2);
> > +extern psci_invoke_fn psci_invoke;
> > +extern int psci_invoke_hvc(unsigned long function_id, unsigned long arg0,
> > + unsigned long arg1, unsigned long arg2);
> > +extern int psci_invoke_smc(unsigned long function_id, unsigned long arg0,
> > + unsigned long arg1, unsigned long arg2);
> > extern int psci_cpu_on(unsigned long cpuid, unsigned long entry_point);
> > extern void psci_system_reset(void);
> > extern int cpu_psci_cpu_boot(unsigned int cpu);
> > diff --git a/lib/arm/psci.c b/lib/arm/psci.c
> > index 936c83948b6a..46300f30822c 100644
> > --- a/lib/arm/psci.c
> > +++ b/lib/arm/psci.c
> > @@ -11,9 +11,11 @@
> > #include <asm/page.h>
> > #include <asm/smp.h>
> > +psci_invoke_fn psci_invoke;
> > +
> > __attribute__((noinline))
> > -int psci_invoke(unsigned long function_id, unsigned long arg0,
> > - unsigned long arg1, unsigned long arg2)
> > +int psci_invoke_hvc(unsigned long function_id, unsigned long arg0,
> > + unsigned long arg1, unsigned long arg2)
> > {
> > asm volatile(
> > "hvc #0"
> > @@ -22,6 +24,17 @@ int psci_invoke(unsigned long function_id, unsigned long arg0,
> > return function_id;
> > }
> > +__attribute__((noinline))
>
> Is noinline necessary? We shouldn't be calling psci_invoke_smc and
> psci_invoke_hmc directly, it's unlikely that the compiler will have a chance
> to inline them. But I might be missing something here because I don't see
> why it was there in psci_invoke either.
The noinline ensures that function_id,arg0,arg1,arg2 are in r0-r3 without
us having to do something like
"mov r0, %0"
"mov r1, %1"
"mov r2, %2"
"mov r3, %3"
in the asm().
>
> Otherwise Reviewed-by: Nikos Nikoleris <nikos.nikoleris@xxxxxxx>
Thanks!
drew
