Re: [PATCH v15 5/6] x86/boot: Parse SRAT address from RSDP and store immovable memory

Borislav Petkov
2019-01-17T15:28:00Z

On Thu, Jan 17, 2019 at 11:20:27AM +0800, Chao Fan wrote:
> I have changed as you suggested, looks clear without type cast, and
> we need some variable as long to calculate the address, and at same
> time as the struct pointer to find it's length, so I change as below,
> and get_acpi_srat_table() return an unsigned long.
> How do you think of that.
>
> int get_immovable_mem_num(void)

I'd call that

int count_immovable_mem_regions(void)

or

int enumerate_immovable_regions(void)

or so and put a comment above it explaining what it does and what it
returns.

"mem_num" is not clear what it is.

> {
> unsigned long table_addr, table_end, table;
> struct acpi_table_header *table_header;
> struct acpi_subtable_header *sub_table;
> char arg[MAX_ACPI_ARG_LENGTH];
> int num = 0;
>
> if (cmdline_find_option("acpi", arg, sizeof(arg)) == 3 &&
> !strncmp(arg, "off", 3))
> return;
>
> table_addr = get_acpi_srat_table();
> if (!table_addr)
> return;
>
> table_header = (struct acpi_table_header *)table_addr;
> table_end = table_addr + table_header->length;
> table = table_addr + sizeof(struct acpi_table_srat);
>
> while (table + sizeof(struct acpi_subtable_header) < table_end) {
> sub_table = (struct acpi_subtable_header *)table;
> if (sub_table->type == ACPI_SRAT_TYPE_MEMORY_AFFINITY) {
> struct acpi_srat_mem_affinity *ma;
>
> ma = (struct acpi_srat_mem_affinity *)table;
> if (!(ma->flags & ACPI_SRAT_MEM_HOT_PLUGGABLE)) {
> immovable_mem[num].start = ma->base_address;
> immovable_mem[num].size = ma->length;
> num++;
> }
>
> if (num >= MAX_NUMNODES*2) {
> debug_putstr("Too many immovable memory regions, aborting.\n");
> return 0;
> }
> }
> table += sub_table->length;
> }
> return num;
> }

That looks clean.

Thx.

--
Regards/Gruss,
Boris.

Good mailing practices for 400: avoid top-posting and trim the reply.