On Wed, Jul 17, 2019 at 7:41 AM Park, Aiden <aiden.p...@intel.com> wrote:
>
> Slim Bootloader provides memory map info thru its HOB list pointer.
> Configure memory size and relocation memory from the HOB data, and
> provide e820 entries as well.
> - Get memory size from the memory map info hob
> - Set ram top for U-Boot relocation lower than 4GB
> - Provide e820 entries from the memory map info hob
> +++ b/arch/x86/cpu/slimbootloader/dram.c
sdram.c is more common name in the sources AFAICS.
> +ulong board_get_usable_ram_top(ulong total_size)
> +{
> + struct memory_map_info *data = NULL;
> + int i = 0;
> + phys_addr_t addr_start = 0;
> + phys_addr_t addr_end = 0;
Unnecessary assignments (check entire series for them).
> + data = (struct memory_map_info *)get_memory_map_info();
Casting from / to void * is redundant. Check entire series.
> + if (!data)
> + panic("memory map info hob not found\n");
> + /**
> + * sorted memory map entries from Slim Bootloader based on physical
> + * start memory address, from low to high. So do reversed search to
> + * get highest usable, suitable size, 4KB aligned available memory
> + * under 4GB.
> + */
> + for (i = data->count - 1; i >= 0; i--) {
Hmm... Maybe
i = data->count;
while (i--) {
...
}
Easier to read.
> + if (data->entry[i].type != E820_RAM)
> + continue;
> +
> + addr_start = data->entry[i].addr;
> + addr_end = addr_start + data->entry[i].size;
> +
> + if (addr_start > SZ_4G)
> + continue;
> +
> + if (addr_end > SZ_4G)
> + addr_end = SZ_4G;
> +
> + if (addr_end < total_size)
> + continue;
> +
> + /* to relocate u-boot at 4K aligned memory */
u-boot -> U-Boot
> + addr_end = rounddown(addr_end - total_size, SZ_4K);
> + if (addr_end >= addr_start) {
> + ram_top = (ulong)addr_end + total_size;
> + break;
> + }
> + }
> +
> + if (!ram_top)
> + panic("failed to find available memory for relocation!");
> +
> + return ram_top;
> +}
> +
> +/**
> + * The memory initialization has already been done in previous Slim
> Bootloader
> + * stage thru FSP-M. Instead, this sets the ram_size from the memory map info
> + * hob.
> + */
> +int dram_init(void)
> +{
> + struct memory_map_info *data = NULL;
> + int i = 0;
> + phys_size_t ram_size = 0;
> +
> + data = (struct memory_map_info *)get_memory_map_info();
> + if (!data)
> + panic("memory map info hob not found\n");
> +
> + /**
> + * sorted memory map entries from Slim Bootloader based on physical
> + * start memory address, from low to high. So do reversed search to
> + * simply get highest usable memory address as ram size
> + */
> + for (i = data->count - 1; i >= 0; i--) {
> + if (data->entry[i].type != E820_RAM)
> + continue;
Second time?
Perhaps you may do rather macro:
#define for_each_map_info_entry_reversed(...) \
for () \
if (!cond) {} else
> +
> + /* simply use the highest usable memory address as ram size */
ram -> RAM
> + ram_size = data->entry[i].addr + data->entry[i].size;
> + break;
> + }
> +
> + if (!ram_size)
> + panic("failed to detect memory size");
> +
> + gd->ram_size = ram_size;
> + return 0;
> +}
> +int dram_init_banksize(void)
> +{
> + /* simply use a single bank to have whole size for now */
> + if (CONFIG_NR_DRAM_BANKS) {
if (!foo) might be slightly better if ever this code gets modified.
> + gd->bd->bi_dram[0].start = 0;
> + gd->bd->bi_dram[0].size = gd->ram_size;
> + }
> + return 0;
> +}
> +#define LOADER_MEMORY_MAP_INFO_GUID \
> + { \
> + 0xa1ff7424, 0x7a1a, 0x478e, \
> + { 0xa9, 0xe4, 0x92, 0xf3, 0x57, 0xd1, 0x28, 0x32 } \
> + }
EFI_GUID() ?
> +/**
> + * A single entry of memory map information
> + *
> + * @addr: start address of a memory map entry
> + * @size: size of a memory map entry
> + * @type: usable:1, reserved:2, acpi:3, nvs:4, unusable:5
> + * @flag: only used in Slim Bootloader
> + * @rsvd: padding for alignment
> + */
> +struct memory_map_entry {
> + phys_addr_t addr;
> + phys_size_t size;
This is comes from hardware, isn't it? Probably better to use fixed width typo
> + u8 type;
> + u8 flag;
> + u8 rsvd[6];
> +} __packed;
--
With Best Regards,
Andy Shevchenko
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