[U-Boot] [PATCHV5 4/6] ARMv8/Layerscape: switch SMP method accordingly

[Zhiqiang Hou]

Hi York,

Thanks for your comments!

> -----Original Message-----
> From: york sun
> Sent: 2016年6月12日 12:07
> To: Zhiqiang Hou <zhiqiang.hou at nxp.com>; u-boot at lists.denx.de;
> albert.u.boot at aribaud.net; scottwood at freescale.com;
> Mingkai.hu at freescale.com; yorksun at freescale.com; leoli at freescale.com;
> prabhakar at freescale.com; bhupesh.sharma at freescale.com
> Subject: Re: [PATCHV5 4/6] ARMv8/Layerscape: switch SMP method accordingly
> 
> On 06/11/2016 08:58 PM, Zhiqiang Hou wrote:
> > Hi York,
> >
> > Thanks for your comments!
> >
> >> -----Original Message-----
> >> From: York Sun [mailto:york.sun at nxp.com]
> >> Sent: 2016年6月8日 8:56
> >> To: Zhiqiang Hou <zhiqiang.hou at nxp.com>; u-boot at lists.denx.de;
> >> albert.u.boot at aribaud.net; scottwood at freescale.com;
> >> Mingkai.hu at freescale.com; yorksun at freescale.com; leoli at freescale.com;
> >> prabhakar at freescale.com; bhupesh.sharma at freescale.com
> >> Subject: Re: [PATCHV5 4/6] ARMv8/Layerscape: switch SMP method
> >> accordingly
> >>
> >> On 06/04/2016 11:40 PM, Zhiqiang Hou wrote:
> >>> From: Hou Zhiqiang <Zhiqiang.Hou at nxp.com>
> >>>
> >>> If the PSCI and PPA is ready, skip the fixup for spin-table and
> >>> waking secondary cores. If not, change SMP method to spin-table, and
> >>> the device node of PSCI will be removed.
> >>>
> >>> Signed-off-by: Hou Zhiqiang <Zhiqiang.Hou at nxp.com>
> >>> ---
> >>> V5:
> >>>   - Changed the checking if the PSCI feature is ready to read the psci version.
> >>>
> >>> V4:
> >>>   - Reordered this patch.
> >>>
> >>>   arch/arm/cpu/armv8/fsl-layerscape/cpu.c | 17 +++++++++++++---
> >>> arch/arm/cpu/armv8/fsl-layerscape/fdt.c | 36
> >>> +++++++++++++++++++++++++++++++++
> >>>   2 files changed, 50 insertions(+), 3 deletions(-)
> >>>
> >>> diff --git a/arch/arm/cpu/armv8/fsl-layerscape/cpu.c
> >>> b/arch/arm/cpu/armv8/fsl-layerscape/cpu.c
> >>> index 672a453..eb566cd 100644
> >>> --- a/arch/arm/cpu/armv8/fsl-layerscape/cpu.c
> >>> +++ b/arch/arm/cpu/armv8/fsl-layerscape/cpu.c
> >>> @@ -23,6 +23,9 @@
> >>>   #ifdef CONFIG_FSL_ESDHC
> >>>   #include <fsl_esdhc.h>
> >>>   #endif
> >>> +#ifdef CONFIG_ARMV8_SEC_FIRMWARE_SUPPORT #include
> >>> +<asm/armv8/sec_firmware.h> #endif
> >>>
> >>>   DECLARE_GLOBAL_DATA_PTR;
> >>>
> >>> @@ -618,6 +621,7 @@ int arch_early_init_r(void)  {  #ifdef CONFIG_MP
> >>>   	int rv = 1;
> >>> +	bool psci_support = false;
> >>>   #endif
> >>>
> >>>   #ifdef CONFIG_SYS_FSL_ERRATUM_A009635 @@ -625,9 +629,16 @@ int
> >>> arch_early_init_r(void)  #endif
> >>>
> >>>   #ifdef CONFIG_MP
> >>> -	rv = fsl_layerscape_wake_seconday_cores();
> >>> -	if (rv)
> >>> -		printf("Did not wake secondary cores\n");
> >>> +#if defined(CONFIG_ARMV8_SEC_FIRMWARE_SUPPORT) &&
> >> defined(CONFIG_ARMV8_PSCI)
> >>> +	/* Check the psci version to determine if the psci is supported */
> >>> +	psci_support = (int)sec_firmware_support_psci_version() > 0 ?
> >>> +			true : false;
> >>
> >> Another comment, even if the function can be used to indicate if psci
> >> is available, do you have to cast it to (int)? I think this can be simplified as
> >> 	psci_support = sec_firmware_support_psci_version() > 0;
> >
> > The type of this func return value is 'unsigned int', so the cast is necessary.
> 
> The return value of function sec_firmware_support_psci_version() may need some
> work. It has three results
> 
> Positive numbers mean success (presuming bit 31 is not used by major number.
> Need to check with PPA code) Zero means image is not valid Negative numbers
> means errors
 
In PSCI spec v1.0, the bit 31 is used by major number, and the type of the return
value is uint, but there isn't any other description for the return value. I don't know
why the PPA isn't consistent with PSCI spec.

> If the error code doesn't include -EINVAL, you can return -EINVAL in case of an
> invalid image. Then you can have
> sec_firmware_support_psci_version() return int.
> 

Thanks,
Zhiqiang