Re: [PATCH v17 08/10] of: fdt: Aggregate the processing of "linux,usable-memory-range"

john.p.donnelly
2021-12-13T14:34:52Z

On 12/10/21 12:55 AM, 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.
>
> Suggested-by: Rob Herring <robh@kernel.org>
> Signed-off-by: Zhen Lei <thunder.leizhen@huawei.com>
> Tested-by: Dave Kleikamp <dave.kleikamp@oracle.com>

Acked-by: John Donnelly <john.p.donnelly@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)