Re: [PATCH v6 2/6] drivers: psci: replace psci firmware calls

Will Deacon
2015-11-02T11:56:01Z

On Thu, Oct 29, 2015 at 09:21:24AM +0100, Jens Wiklander wrote:
> Switch to use a generic interface for issuing SMC/HVC based on ARM SMC
> Calling Convention. Removes now the now unused psci-call.S.
>
> Signed-off-by: Jens Wiklander <jens.wiklander@linaro.org>
> ---
> arch/arm/kernel/Makefile | 1 -
> arch/arm/kernel/psci-call.S | 31 -------------------------------
> arch/arm64/kernel/Makefile | 2 +-
> arch/arm64/kernel/psci-call.S | 28 ----------------------------
> drivers/firmware/psci.c | 21 +++++++++++++++++++--
> 5 files changed, 20 insertions(+), 63 deletions(-)
> delete mode 100644 arch/arm/kernel/psci-call.S
> delete mode 100644 arch/arm64/kernel/psci-call.S

[...]

> diff --git a/drivers/firmware/psci.c b/drivers/firmware/psci.c
> index 42700f0..53c9606 100644
> --- a/drivers/firmware/psci.c
> +++ b/drivers/firmware/psci.c
> @@ -19,6 +19,7 @@
> #include <linux/pm.h>
> #include <linux/printk.h>
> #include <linux/psci.h>
> +#include <linux/arm-smccc.h>
> #include <linux/reboot.h>
>
> #include <uapi/linux/psci.h>
> @@ -56,8 +57,6 @@ struct psci_operations psci_ops;
>
> typedef unsigned long (psci_fn)(unsigned long, unsigned long,
> unsigned long, unsigned long);
> -asmlinkage psci_fn __invoke_psci_fn_hvc;
> -asmlinkage psci_fn __invoke_psci_fn_smc;
> static psci_fn *invoke_psci_fn;
>
> enum psci_function {
> @@ -70,6 +69,24 @@ enum psci_function {
>
> static u32 psci_function_id[PSCI_FN_MAX];
>
> +static unsigned long __invoke_psci_fn_hvc(unsigned long a0, unsigned long a1,
> + unsigned long a2, unsigned long a3)

Minor comment, but could we keep these argument names the same as before
please?

> +{
> + struct smccc_res res;
> +
> + smccc_hvc(a0, a1, a2, a3, 0, 0, 0, 0, &res);

It's slightly tempting to use varargs instead of the '0' argument padding,
but that will probably make the asm code unmanageable.

Will