Re: 回复: 回复: [PATCH] firmware: scmi: Drop mmu_set_region_dcache_behaviour() misuse

[Marek Vasut]

On 10/30/25 4:58 AM, Alice Guo (OSS) wrote:

Hello Alice,

>>>> diff --git a/drivers/firmware/scmi/smt.c
>>>> b/drivers/firmware/scmi/smt.c index
>>>> 237871559f0..cd1c0801f72 100644
>>>> --- a/drivers/firmware/scmi/smt.c
>>>> +++ b/drivers/firmware/scmi/smt.c
>>>> @@ -61,20 +61,6 @@ int scmi_dt_get_smt_buffer(struct udevice *dev,
>>>> struct scmi_smt *smt)
>>>>    	if (device_is_compatible(dev, "arm,scmi") &&
>>>> ofnode_has_property(dev_ofnode(dev), "mboxes"))
>>>>    		scmi_smt_enable_intr(smt, true);
>>>>
>>>> -#ifdef CONFIG_ARM
>>>> -	if (dcache_status()) {
>>>> -		u32 align_size;
>>>> -
>>>> -		if (IS_ENABLED(CONFIG_ARM64))
>>>> -			align_size = PAGE_SIZE;
>>>> -		else
>>>> -			align_size = MMU_SECTION_SIZE;
>>>> -
>>>> -
>>>> 	mmu_set_region_dcache_behaviour(ALIGN_DOWN((uintptr_t)smt->buf,
>>>> align_size),
>>>> -						ALIGN(smt->size, align_size), DCACHE_OFF);
>>>> -	}
>>>> -#endif
>>>> -
>>>>    	return 0;
>>>>    }
>>>>
>>>> --
>>>> 2.51.0
>>>
>>> Tested-by: Alice Guo <alice.guo at nxp.com>
>>>
>>> Tested on two boards: IMX94 and IMX95. No regressions were observed
>> during boot. Looks good to me.
>> Thank you !
> 
> Hi Marek,
> 
> Applied this patch on the U-Boot NXP tree and found that it affects the i.MX8ULP. On i.MX8ULP, the SCMI buffer is in SRAM and mapped as normal memory.

Thank you for testing, this helps greatly !

Would it be possible to fix up the SRAM mapping in:

arch/arm/mach-imx/imx8ulp/soc.c:static struct mm_region 
imx8ulp_arm64_mem_map[] = {

?

-- 
Best regards,
Marek Vasut