Hi Drew,
On 4/22/21 5:17 PM, Andrew Jones wrote:
> For v3, I've done the following changes (inline)
>
> On Wed, Apr 21, 2021 at 09:02:06AM +0200, Andrew Jones wrote:
>> On Tue, Apr 20, 2021 at 09:00:02PM +0200, 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/cstart.S | 22 ++++++++++++++++++++++
>>> arm/cstart64.S | 22 ++++++++++++++++++++++
>>> arm/selftest.c | 34 +++++++---------------------------
>>> lib/arm/asm/psci.h | 10 ++++++++--
>>> lib/arm/psci.c | 37 +++++++++++++++++++++++++++++--------
>>> lib/arm/setup.c | 2 ++
>>> 6 files changed, 90 insertions(+), 37 deletions(-)
>>>
>>> diff --git a/arm/cstart.S b/arm/cstart.S
>>> index 446966de350d..2401d92cdadc 100644
>>> --- a/arm/cstart.S
>>> +++ b/arm/cstart.S
>>> @@ -95,6 +95,28 @@ start:
>>>
>>> .text
>>>
>>> +/*
>>> + * psci_invoke_hvc / psci_invoke_smc
>>> + *
>>> + * Inputs:
>>> + * r0 -- function_id
>>> + * r1 -- arg0
>>> + * r2 -- arg1
>>> + * r3 -- arg2
>>> + *
>>> + * Outputs:
>>> + * r0 -- return code
>>> + */
>>> +.globl psci_invoke_hvc
>>> +psci_invoke_hvc:
>>> + hvc #0
>>> + mov pc, lr
>>> +
>>> +.globl psci_invoke_smc
>>> +psci_invoke_smc:
>>> + smc #0
>>> + mov pc, lr
>>> +
>>> enable_vfp:
>>> /* Enable full access to CP10 and CP11: */
>>> mov r0, #(3 << 22 | 3 << 20)
>>> diff --git a/arm/cstart64.S b/arm/cstart64.S
>>> index 42ba3a3ca249..7610e28f06dd 100644
>>> --- a/arm/cstart64.S
>>> +++ b/arm/cstart64.S
>>> @@ -109,6 +109,28 @@ start:
>>>
>>> .text
>>>
>>> +/*
>>> + * psci_invoke_hvc / psci_invoke_smc
>>> + *
>>> + * Inputs:
>>> + * x0 -- function_id
> changed this comment to be 'w0 -- function_id'
>
>>> + * x1 -- arg0
>>> + * x2 -- arg1
>>> + * x3 -- arg2
>>> + *
>>> + * Outputs:
>>> + * x0 -- return code
>>> + */
>>> +.globl psci_invoke_hvc
>>> +psci_invoke_hvc:
>>> + hvc #0
>>> + ret
>>> +
>>> +.globl psci_invoke_smc
>>> +psci_invoke_smc:
>>> + smc #0
>>> + ret
>>> +
>>> get_mmu_off:
>>> adrp x0, auxinfo
>>> ldr x0, [x0, :lo12:auxinfo + 8]
>>> 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..2820c0a3afc7 100644
>>> --- a/lib/arm/asm/psci.h
>>> +++ b/lib/arm/asm/psci.h
>>> @@ -3,8 +3,14 @@
>>> #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);
> The prototypes are now
>
> long invoke_fn(unsigned int function_id, unsigned long arg0,
> unsigned long arg1, unsigned long arg2)
>
> Notice the return value changed to long and the function_id to
> unsigned int.
Strictly speaking, arm always returns an unsigned long (32bits), but arm64 can
return either an unsigned long (64bits) when using SMC64/HVC64, or an unsigned int
(32bits) when using SMC32/HVC32. But, I did check C99 and it says that the
original value is unchanged if it fits in the new type (section 6.3.1.3), so we
can just cast the result to an unsigned if we ever want to use SMC32/HVC32 on arm64.
The declaration for psci_invoke_none should also be changed, but otherwise looks good.
Thanks,
Alex
>
>
> I also improved the commit message by adding the following:
>
> The method can be smc in addition to hvc, and it will be when running
> on bare metal. Additionally, we move the invocations to assembly so
> we don't have to rely on compiler assumptions. We also fix the
> prototype of psci_invoke. It should return long, not int, and
> function_id should be an unsigned int, not an unsigned long.
>
> Thanks,
> drew
>
