Re: [Minios-devel] [UNIKRAFT PATCHv4 33/43] plat/kvm: Get PSCI conduit method from DTB for arm64

[Julien Grall <julien.grall@xxxxxxx>]

Hi Wei,

On 06/07/18 10:03, Wei Chen wrote:
> PSCI supports two conduit method: HVC and SMC. The method
> would be set value in device tree's PSCI node. This value
> would decide which instruction we should use to call PSCI
> functions.
>
> Signed-off-by: Wei Chen <Wei.Chen@xxxxxxx>
> ---
>   plat/common/include/arm/arm64/cpu.h |  6 +++++
>   plat/kvm/arm/setup.c                | 39 +++++++++++++++++++++++++++++
>   2 files changed, 45 insertions(+)
>
> diff --git a/plat/common/include/arm/arm64/cpu.h 
> b/plat/common/include/arm/arm64/cpu.h
> index 7c79462..cf0f6a2 100644
> --- a/plat/common/include/arm/arm64/cpu.h
> +++ b/plat/common/include/arm/arm64/cpu.h
> @@ -70,3 +70,9 @@
>   #define       SYSREG_WRITE(reg, val)      \
>         __asm__ __volatile__("msr " __STRINGIFY(reg) ", %0" \
>                                         : : "r" ((uint64_t)(val)))
> +
> +
No need for 2 newline here.

> +/* PSCI conduit types */
> +#define PSCI_METHOD_NONE       0x0
> +#define PSCI_METHOD_HVC                0x1
> +#define PSCI_METHOD_SMC                0x2
It feels like this should be an enum.

> diff --git a/plat/kvm/arm/setup.c b/plat/kvm/arm/setup.c
> index 685308c..b7f3e47 100644
> --- a/plat/kvm/arm/setup.c
> +++ b/plat/kvm/arm/setup.c
> @@ -35,6 +35,7 @@
>   #include <uk/plat/console.h>
>   #include <uk/assert.h>
>   #include <uk/essentials.h>
> +#include <arm/cpu.h>
>   #include <arm/cpu_defs.h>
>   
>   #define MAX_CMDLINE_SIZE 1024
> @@ -46,6 +47,8 @@ void *_libkvmplat_stack_top;
>   void *_libkvmplat_mem_end;
>   void *_libkvmplat_dtb;
>   
> +int psci_method;
> +
>   static void _init_dtb(void *dtb_pointer)
>   {
>         int ret;
> @@ -83,6 +86,39 @@ enocmdl:
>         strcpy(cmdline, CONFIG_UK_NAME);
>   }
>   
> +static void _dtb_get_psci_method(void)
> +{
> +       int fdtpsci, len;
> +       const char *fdtmethod;
> +
> +       fdtpsci = fdt_node_offset_by_compatible(_libkvmplat_dtb,
> +                                               0, "arm,psci-0.2");
> +       if (fdtpsci < 0)
> +               fdtpsci = fdt_node_offset_by_compatible(_libkvmplat_dtb,
> +                                                       0, "arm,psci-0.1");
Looking at the bindings, I can't find the compatible arm,psci-0.1. Where 
does it come from?
Also, you may want to check the compatible "arm,psci-1.0".

> +       if (fdtpsci < 0) {
> +               uk_printd(DLVL_INFO, "No PSCI conduit found in DTB\n");
> +               goto enomethod;
> +       }
> +
> +       fdtmethod = fdt_getprop(_libkvmplat_dtb, fdtpsci, "method", &len);
> +       if (!fdtmethod || (len <= 0)) {
> +               uk_printd(DLVL_INFO, "No PSCI method found\n");
> +               goto enomethod;
> +       }
> +
> +       if (!strcmp(fdtmethod, "hvc"))
> +               psci_method = PSCI_METHOD_HVC;
> +       else if (!strcmp(fdtmethod, "smc"))
> +               psci_method = PSCI_METHOD_SMC;
> +
> +       uk_printd(DLVL_INFO, "PSCI method: %s, %d\n", fdtmethod, psci_method);
> +       return;
> +
> +enomethod:
> +       psci_method = PSCI_METHOD_NONE;
> +}
> +
>   static void _init_dtb_mem(void)
>   {
>         extern char _text[];
> @@ -146,6 +182,9 @@ void _libkvmplat_start(void *dtb_pointer)
>         /* Get command line from DTB */
>         _dtb_get_cmdline(cmdline, sizeof(cmdline));
>   
> +	/* Get PSCI method from DTB */
> +       _dtb_get_psci_method();
> +
>         /* Initialize memory from DTB */
>         _init_dtb_mem();
>   
Cheers,


--
Julien Grall

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