Re: [PATCH 4/6] arm: mach-k3: am62: Fixup TF-A/OP-TEE reserved-memory node in FDT

[Andrew Davis <afd@ti.com>]

On 2/28/24 12:24 AM, Manorit Chawdhry wrote:
> Hi Andrew,
> 
> On 10:30-20240214, Andrew Davis wrote:
>> The address we load TF-A and OP-TEE to is configurable by Kconfig
>> CONFIG_K3_{ATF,OPTEE}_LOAD_ADDR, but the DT nodes reserving this memory
>> are often statically defined. As these binaries are dynamically loadable,
>> and in the case of OP-TEE may not even be loaded at all, hard-coding these
>> addresses is not a hardware description, but rather a configuration.
>>
>> If the address that U-Boot loaded TF-A or OP-TEE does not match the
>> address in hard-coded in DT, then fix that node address. This also handles
>> the case when no reserved memory for these is provided by DT, which is
>> more correct as explained above.
>>
>> Add this fixup function, and enable it for AM62.
> 
> Why are we doing it only for AM62? Assuming that this can help in other
> devices as well as all the DTs ideally should have these reserved nodes
> in DT?

Only AM62(a) have TF-A in DRAM, the rest of K3 put it in SRAM which
means it wont need to be moved currently. If we ever do move TF-A to
DRAM for other devices then they could make use of this helper function
just the same.

Andrew

> 
> Regards,
> Manorit
>>
>> Signed-off-by: Andrew Davis <afd@ti.com>
>> ---
>>   arch/arm/mach-k3/am625_fdt.c  |  2 ++
>>   arch/arm/mach-k3/common_fdt.c | 52 +++++++++++++++++++++++++++++++++++
>>   arch/arm/mach-k3/common_fdt.h |  2 ++
>>   3 files changed, 56 insertions(+)
>>
>> diff --git a/arch/arm/mach-k3/am625_fdt.c b/arch/arm/mach-k3/am625_fdt.c
>> index 970dd3447de..b26186456f3 100644
>> --- a/arch/arm/mach-k3/am625_fdt.c
>> +++ b/arch/arm/mach-k3/am625_fdt.c
>> @@ -43,6 +43,8 @@ int ft_system_setup(void *blob, struct bd_info *bd)
>>   	fdt_fixup_cores_nodes_am625(blob, k3_get_core_nr());
>>   	fdt_fixup_gpu_nodes_am625(blob, k3_has_gpu());
>>   	fdt_fixup_pru_node_am625(blob, k3_has_pru());
>> +	fdt_fixup_reserved(blob, "tfa", CONFIG_K3_ATF_LOAD_ADDR, 0x80000);
>> +	fdt_fixup_reserved(blob, "optee", CONFIG_K3_OPTEE_LOAD_ADDR, 0x1800000);
>>   
>>   	return 0;
>>   }
>> diff --git a/arch/arm/mach-k3/common_fdt.c b/arch/arm/mach-k3/common_fdt.c
>> index 645c4de42f7..3bdedd7b509 100644
>> --- a/arch/arm/mach-k3/common_fdt.c
>> +++ b/arch/arm/mach-k3/common_fdt.c
>> @@ -112,3 +112,55 @@ int fdt_del_node_path(void *blob, const char *path)
>>   
>>   	return ret;
>>   }
>> +
>> +int fdt_fixup_reserved(void *blob, const char *name,
>> +		       unsigned int new_address, unsigned int new_size)
>> +{
>> +	int nodeoffset, subnode;
>> +	int ret;
>> +
>> +	/* Find reserved-memory */
>> +	nodeoffset = fdt_subnode_offset(blob, 0, "reserved-memory");
>> +	if (nodeoffset < 0) {
>> +		debug("Could not find reserved-memory node\n");
>> +		return 0;
>> +	}
>> +
>> +	/* Find existing matching subnode and remove it */
>> +	fdt_for_each_subnode(subnode, blob, nodeoffset) {
>> +		const char *node_name;
>> +		fdt_addr_t addr;
>> +		fdt_size_t size;
>> +
>> +		/* Name matching */
>> +		node_name = fdt_get_name(blob, subnode, NULL);
>> +		if (!name)
>> +			return -EINVAL;
>> +		if (!strncmp(node_name, name, strlen(name))) {
>> +			/* Read out old size first */
>> +			addr = fdtdec_get_addr_size(blob, subnode, "reg", &size);
>> +			if (addr == FDT_ADDR_T_NONE)
>> +				return -EINVAL;
>> +			new_size = size;
>> +
>> +			/* Delete node */
>> +			ret = fdt_del_node(blob, subnode);
>> +			if (ret < 0)
>> +				return ret;
>> +
>> +			/* Only one matching node */
>> +			break;
>> +		}
>> +	}
>> +
>> +	struct fdt_memory carveout = {
>> +		.start = new_address,
>> +		.end = new_address + new_size - 1,
>> +	};
>> +	ret = fdtdec_add_reserved_memory(blob, name, &carveout, NULL, 0, NULL,
>> +					 FDTDEC_RESERVED_MEMORY_NO_MAP);
>> +	if (ret < 0)
>> +		return ret;
>> +
>> +	return 0;
>> +}
>> diff --git a/arch/arm/mach-k3/common_fdt.h b/arch/arm/mach-k3/common_fdt.h
>> index 4d23ae638ca..52c07957483 100644
>> --- a/arch/arm/mach-k3/common_fdt.h
>> +++ b/arch/arm/mach-k3/common_fdt.h
>> @@ -8,5 +8,7 @@
>>   
>>   int fdt_fixup_msmc_ram_k3(void *blob);
>>   int fdt_del_node_path(void *blob, const char *path);
>> +int fdt_fixup_reserved(void *blob, const char *name,
>> +		       unsigned int new_address, unsigned int new_size);
>>   
>>   #endif /* _COMMON_FDT_H */
>> -- 
>> 2.39.2
>>