[PATCH 1/2] lib: utils: Implement "64bit-mmio" property parsing

[Jessica Clarke]

On 17 Apr 2021, at 12:41, Jessica Clarke <jrtc27 at jrtc27.com> wrote:
> 
> On 13 Apr 2021, at 04:44, guoren at kernel.org wrote:
>> 
>> From: Guo Ren <guoren at linux.alibaba.com>
>> 
>> Figure out CLINT has_64bit_mmio from DT node and using antonym for
>> compatibility.
>> 
>> Signed-off-by: Guo Ren <guoren at linux.alibaba.com>
>> Cc: Anup Patel <anup.patel at wdc.com>
>> Cc: Xiang W <wxjstz at 126.com>
>> ---
>> lib/utils/fdt/fdt_helper.c | 3 ++-
>> 1 file changed, 2 insertions(+), 1 deletion(-)
>> 
>> diff --git a/lib/utils/fdt/fdt_helper.c b/lib/utils/fdt/fdt_helper.c
>> index bf19ff9..909de01 100644
>> --- a/lib/utils/fdt/fdt_helper.c
>> +++ b/lib/utils/fdt/fdt_helper.c
>> @@ -442,8 +442,9 @@ int fdt_parse_clint_node(void *fdt, int nodeoffset, bool for_timer,
>> 	if (clint->hart_count < count)
>> 		clint->hart_count = count;
>> 
>> -	/* TODO: We should figure-out CLINT has_64bit_mmio from DT node */
>> 	clint->has_64bit_mmio = TRUE;
>> +	if (fdt_getprop(fdt, nodeoffset, "clint,has-no-64bit-mmio", &count))
> 
> I do not see this specified in clint.yaml.

Also, the RISC-V privileged is very clear:

> For RV64, naturally aligned 64-bit memory accesses to the mtime and mtimecmp
> registers are atomic.

So I would say your CLINT violates the spec and thus should not claim to be a
RISC-V or SiFive-compatible CLINT.

Jess