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/*
* Copyright (c) 2016-2018, NVIDIA CORPORATION.
*
* SPDX-License-Identifier: GPL-2.0+
*/
#include <common.h>
#include <fdt_support.h>
#include <fdtdec.h>
#include <asm/arch/tegra.h>
#include <asm/armv8/mmu.h>
#define SZ_4G 0x100000000ULL
/*
* Size of a region that's large enough to hold the relocated U-Boot and all
* other allocations made around it (stack, heap, page tables, etc.)
* In practice, running "bdinfo" at the shell prompt, the stack reaches about
* 5MB from the address selected for ram_top as of the time of writing,
* so a 16MB region should be plenty.
*/
#define MIN_USABLE_RAM_SIZE SZ_16M
/*
* The amount of space we expect to require for stack usage. Used to validate
* that all reservations fit into the region selected for the relocation target
*/
#define MIN_USABLE_STACK_SIZE SZ_1M
DECLARE_GLOBAL_DATA_PTR;
extern unsigned long nvtboot_boot_x0;
extern struct mm_region tegra_mem_map[];
/*
* These variables are written to before relocation, and hence cannot be
* in.bss, since .bss overlaps the DTB that's appended to the U-Boot binary.
* The section attribute forces this into .data and avoids this issue. This
* also has the nice side-effect of the content being valid after relocation.
*/
/* The number of valid entries in ram_banks[] */
static int ram_bank_count __attribute__((section(".data")));
/*
* The usable top-of-RAM for U-Boot. This is both:
* a) Below 4GB to avoid issues with peripherals that use 32-bit addressing.
* b) At the end of a region that has enough space to hold the relocated U-Boot
* and all other allocations made around it (stack, heap, page tables, etc.)
*/
static u64 ram_top __attribute__((section(".data")));
/* The base address of the region of RAM that ends at ram_top */
static u64 region_base __attribute__((section(".data")));
int dram_init(void)
{
unsigned int na, ns;
const void *nvtboot_blob = (void *)nvtboot_boot_x0;
int node, len, i;
const u32 *prop;
na = fdtdec_get_uint(nvtboot_blob, 0, "#address-cells", 2);
ns = fdtdec_get_uint(nvtboot_blob, 0, "#size-cells", 2);
node = fdt_path_offset(nvtboot_blob, "/memory");
if (node < 0) {
pr_err("Can't find /memory node in nvtboot DTB");
hang();
}
prop = fdt_getprop(nvtboot_blob, node, "reg", &len);
if (!prop) {
pr_err("Can't find /memory/reg property in nvtboot DTB");
hang();
}
/* Calculate the true # of base/size pairs to read */
len /= 4; /* Convert bytes to number of cells */
len /= (na + ns); /* Convert cells to number of banks */
if (len > CONFIG_NR_DRAM_BANKS)
len = CONFIG_NR_DRAM_BANKS;
/* Parse the /memory node, and save useful entries */
gd->ram_size = 0;
ram_bank_count = 0;
for (i = 0; i < len; i++) {
u64 bank_start, bank_end, bank_size, usable_bank_size;
/* Extract raw memory region data from DTB */
bank_start = fdt_read_number(prop, na);
prop += na;
bank_size = fdt_read_number(prop, ns);
prop += ns;
gd->ram_size += bank_size;
bank_end = bank_start + bank_size;
debug("Bank %d: %llx..%llx (+%llx)\n", i,
bank_start, bank_end, bank_size);
/*
* Align the bank to MMU section size. This is not strictly
* necessary, since the translation table construction code
* handles page granularity without issue. However, aligning
* the MMU entries reduces the size and number of levels in the
* page table, so is worth it.
*/
bank_start = ROUND(bank_start, SZ_2M);
bank_end = bank_end & ~(SZ_2M - 1);
bank_size = bank_end - bank_start;
debug(" aligned: %llx..%llx (+%llx)\n",
bank_start, bank_end, bank_size);
if (bank_end <= bank_start)
continue;
/* Record data used to create MMU translation tables */
ram_bank_count++;
/* Index below is deliberately 1-based to skip MMIO entry */
tegra_mem_map[ram_bank_count].virt = bank_start;
tegra_mem_map[ram_bank_count].phys = bank_start;
tegra_mem_map[ram_bank_count].size = bank_size;
tegra_mem_map[ram_bank_count].attrs =
PTE_BLOCK_MEMTYPE(MT_NORMAL) | PTE_BLOCK_INNER_SHARE;
/* Determine best bank to relocate U-Boot into */
if (bank_end > SZ_4G)
bank_end = SZ_4G;
debug(" end %llx (usable)\n", bank_end);
usable_bank_size = bank_end - bank_start;
debug(" size %llx (usable)\n", usable_bank_size);
if ((usable_bank_size >= MIN_USABLE_RAM_SIZE) &&
(bank_end > ram_top)) {
ram_top = bank_end;
region_base = bank_start;
debug("ram top now %llx\n", ram_top);
}
}
/* Ensure memory map contains the desired sentinel entry */
tegra_mem_map[ram_bank_count + 1].virt = 0;
tegra_mem_map[ram_bank_count + 1].phys = 0;
tegra_mem_map[ram_bank_count + 1].size = 0;
tegra_mem_map[ram_bank_count + 1].attrs = 0;
/* Error out if a relocation target couldn't be found */
if (!ram_top) {
pr_err("Can't find a usable RAM top");
hang();
}
return 0;
}
int dram_init_banksize(void)
{
int i;
if ((gd->start_addr_sp - region_base) < MIN_USABLE_STACK_SIZE) {
pr_err("Reservations exceed chosen region size");
hang();
}
for (i = 0; i < ram_bank_count; i++) {
gd->bd->bi_dram[i].start = tegra_mem_map[1 + i].virt;
gd->bd->bi_dram[i].size = tegra_mem_map[1 + i].size;
}
#ifdef CONFIG_PCI
gd->pci_ram_top = ram_top;
#endif
return 0;
}
ulong board_get_usable_ram_top(ulong total_size)
{
return ram_top;
}
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