Re: [PATCH v18 15/17] of: fdt: Aggregate the processing of "linux,usable-memory-range"

["Leizhen (ThunderTown)" <thunder.leizhen@huawei.com>]

On 2021/12/23 23:48, Dave Kleikamp wrote:
> On 12/22/21 7:08AM, Zhen Lei wrote:
>> Currently, we parse the "linux,usable-memory-range" property in
>> early_init_dt_scan_chosen(), to obtain the specified memory range of the
>> crash kernel. We then reserve the required memory after
>> early_init_dt_scan_memory() has identified all available physical memory.
>> Because the two pieces of code are separated far, the readability and
>> maintainability are reduced. So bring them together.
> 
> Rob Herring is pushing a modified version of this patch (changes made by
> Pingfan Liu) to fix a regression. This will cause a conflict when it hits
> mainline.

Yes, I saw it yesterday, and I'll delete it in the next version. Thanks.

> 
> https://git.kernel.org/pub/scm/linux/kernel/git/robh/linux.git/log/?h=dt/linus
> 
> https://lore.kernel.org/linux-arm-kernel/20211214040157.27443-1-kernelfans@gmail.com/
> 
>>
>> Suggested-by: Rob Herring <robh@kernel.org>
>> Signed-off-by: Zhen Lei <thunder.leizhen@huawei.com>
>> Reviewed-by: Rob Herring <robh@kernel.org>
>> Tested-by: Dave Kleikamp <dave.kleikamp@oracle.com>
>> ---
>>   drivers/of/fdt.c | 15 +++++++++++----
>>   1 file changed, 11 insertions(+), 4 deletions(-)
>>
>> diff --git a/drivers/of/fdt.c b/drivers/of/fdt.c
>> index bdca35284cebd56..37b477a51175359 100644
>> --- a/drivers/of/fdt.c
>> +++ b/drivers/of/fdt.c
>> @@ -965,8 +965,7 @@ static void __init early_init_dt_check_for_elfcorehdr(unsigned long node)
>>            elfcorehdr_addr, elfcorehdr_size);
>>   }
>>   -static phys_addr_t cap_mem_addr;
>> -static phys_addr_t cap_mem_size;
>> +static unsigned long chosen_node_offset = -FDT_ERR_NOTFOUND;
>>     /**
>>    * early_init_dt_check_for_usable_mem_range - Decode usable memory range
>> @@ -977,6 +976,11 @@ static void __init early_init_dt_check_for_usable_mem_range(unsigned long node)
>>   {
>>       const __be32 *prop;
>>       int len;
>> +    phys_addr_t cap_mem_addr;
>> +    phys_addr_t cap_mem_size;
>> +
>> +    if ((long)node < 0)
>> +        return;
>>         pr_debug("Looking for usable-memory-range property... ");
>>   @@ -989,6 +993,8 @@ static void __init early_init_dt_check_for_usable_mem_range(unsigned long node)
>>         pr_debug("cap_mem_start=%pa cap_mem_size=%pa\n", &cap_mem_addr,
>>            &cap_mem_size);
>> +
>> +    memblock_cap_memory_range(cap_mem_addr, cap_mem_size);
>>   }
>>     #ifdef CONFIG_SERIAL_EARLYCON
>> @@ -1137,9 +1143,10 @@ int __init early_init_dt_scan_chosen(unsigned long node, const char *uname,
>>           (strcmp(uname, "chosen") != 0 && strcmp(uname, "chosen@0") != 0))
>>           return 0;
>>   +    chosen_node_offset = node;
>> +
>>       early_init_dt_check_for_initrd(node);
>>       early_init_dt_check_for_elfcorehdr(node);
>> -    early_init_dt_check_for_usable_mem_range(node);
>>         /* Retrieve command line */
>>       p = of_get_flat_dt_prop(node, "bootargs", &l);
>> @@ -1275,7 +1282,7 @@ void __init early_init_dt_scan_nodes(void)
>>       of_scan_flat_dt(early_init_dt_scan_memory, NULL);
>>         /* Handle linux,usable-memory-range property */
>> -    memblock_cap_memory_range(cap_mem_addr, cap_mem_size);
>> +    early_init_dt_check_for_usable_mem_range(chosen_node_offset);
>>   }
>>     bool __init early_init_dt_scan(void *params)
> 
> .
>