kernel_optimize_test/arch/mips/generic/yamon-dt.c
Paul Burton f41d2430bb MIPS: generic/yamon-dt: Support > 256MB of RAM
YAMON can expose more than 256MB of RAM to Linux on Malta by passing an
ememsize environment variable with the full size, but the kernel then
needs to be careful to choose the corresponding physical memory regions,
avoiding the IO memory window. This is platform dependent, and on Malta
it also depends on the memory layout which varies between system
controllers.

Extend yamon_dt_amend_memory() to generically handle this by taking
[e]memsize bytes of memory from an array of memory regions passed in as
a new parameter. Board code provides this array as appropriate depending
on its own memory map.

[paul.burton@imgtec.com: SEAD-3 supports 384MB DDR from 0]

Signed-off-by: James Hogan <james.hogan@imgtec.com>
Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/16182/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2017-06-28 12:22:41 +02:00

241 lines
6.0 KiB
C

/*
* Copyright (C) 2016 Imagination Technologies
* Author: Paul Burton <paul.burton@imgtec.com>
*
* This program is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License as published by the
* Free Software Foundation; either version 2 of the License, or (at your
* option) any later version.
*/
#define pr_fmt(fmt) "yamon-dt: " fmt
#include <linux/bug.h>
#include <linux/errno.h>
#include <linux/kernel.h>
#include <linux/libfdt.h>
#include <linux/printk.h>
#include <asm/fw/fw.h>
#include <asm/yamon-dt.h>
#define MAX_MEM_ARRAY_ENTRIES 2
__init int yamon_dt_append_cmdline(void *fdt)
{
int err, chosen_off;
/* find or add chosen node */
chosen_off = fdt_path_offset(fdt, "/chosen");
if (chosen_off == -FDT_ERR_NOTFOUND)
chosen_off = fdt_path_offset(fdt, "/chosen@0");
if (chosen_off == -FDT_ERR_NOTFOUND)
chosen_off = fdt_add_subnode(fdt, 0, "chosen");
if (chosen_off < 0) {
pr_err("Unable to find or add DT chosen node: %d\n",
chosen_off);
return chosen_off;
}
err = fdt_setprop_string(fdt, chosen_off, "bootargs", fw_getcmdline());
if (err) {
pr_err("Unable to set bootargs property: %d\n", err);
return err;
}
return 0;
}
static unsigned int __init gen_fdt_mem_array(
const struct yamon_mem_region *regions,
__be32 *mem_array,
unsigned int max_entries,
unsigned long memsize)
{
const struct yamon_mem_region *mr;
unsigned long size;
unsigned int entries = 0;
for (mr = regions; mr->size && memsize; ++mr) {
if (entries >= max_entries) {
pr_warn("Number of regions exceeds max %u\n",
max_entries);
break;
}
/* How much of the remaining RAM fits in the next region? */
size = min_t(unsigned long, memsize, mr->size);
memsize -= size;
/* Emit a memory region */
*(mem_array++) = cpu_to_be32(mr->start);
*(mem_array++) = cpu_to_be32(size);
++entries;
/* Discard the next mr->discard bytes */
memsize -= min_t(unsigned long, memsize, mr->discard);
}
return entries;
}
__init int yamon_dt_append_memory(void *fdt,
const struct yamon_mem_region *regions)
{
unsigned long phys_memsize, memsize;
__be32 mem_array[2 * MAX_MEM_ARRAY_ENTRIES];
unsigned int mem_entries;
int i, err, mem_off;
char *var, param_name[10], *var_names[] = {
"ememsize", "memsize",
};
/* find memory size from the bootloader environment */
for (i = 0; i < ARRAY_SIZE(var_names); i++) {
var = fw_getenv(var_names[i]);
if (!var)
continue;
err = kstrtoul(var, 0, &phys_memsize);
if (!err)
break;
pr_warn("Failed to read the '%s' env variable '%s'\n",
var_names[i], var);
}
if (!phys_memsize) {
pr_warn("The bootloader didn't provide memsize: defaulting to 32MB\n");
phys_memsize = 32 << 20;
}
/* default to using all available RAM */
memsize = phys_memsize;
/* allow the user to override the usable memory */
for (i = 0; i < ARRAY_SIZE(var_names); i++) {
snprintf(param_name, sizeof(param_name), "%s=", var_names[i]);
var = strstr(arcs_cmdline, param_name);
if (!var)
continue;
memsize = memparse(var + strlen(param_name), NULL);
}
/* if the user says there's more RAM than we thought, believe them */
phys_memsize = max_t(unsigned long, phys_memsize, memsize);
/* find or add a memory node */
mem_off = fdt_path_offset(fdt, "/memory");
if (mem_off == -FDT_ERR_NOTFOUND)
mem_off = fdt_add_subnode(fdt, 0, "memory");
if (mem_off < 0) {
pr_err("Unable to find or add memory DT node: %d\n", mem_off);
return mem_off;
}
err = fdt_setprop_string(fdt, mem_off, "device_type", "memory");
if (err) {
pr_err("Unable to set memory node device_type: %d\n", err);
return err;
}
mem_entries = gen_fdt_mem_array(regions, mem_array,
MAX_MEM_ARRAY_ENTRIES, phys_memsize);
err = fdt_setprop(fdt, mem_off, "reg",
mem_array, mem_entries * 2 * sizeof(mem_array[0]));
if (err) {
pr_err("Unable to set memory regs property: %d\n", err);
return err;
}
mem_entries = gen_fdt_mem_array(regions, mem_array,
MAX_MEM_ARRAY_ENTRIES, memsize);
err = fdt_setprop(fdt, mem_off, "linux,usable-memory",
mem_array, mem_entries * 2 * sizeof(mem_array[0]));
if (err) {
pr_err("Unable to set linux,usable-memory property: %d\n", err);
return err;
}
return 0;
}
__init int yamon_dt_serial_config(void *fdt)
{
const char *yamontty, *mode_var;
char mode_var_name[9], path[18], parity;
unsigned int uart, baud, stop_bits;
bool hw_flow;
int chosen_off, err;
yamontty = fw_getenv("yamontty");
if (!yamontty || !strcmp(yamontty, "tty0")) {
uart = 0;
} else if (!strcmp(yamontty, "tty1")) {
uart = 1;
} else {
pr_warn("yamontty environment variable '%s' invalid\n",
yamontty);
uart = 0;
}
baud = stop_bits = 0;
parity = 0;
hw_flow = false;
snprintf(mode_var_name, sizeof(mode_var_name), "modetty%u", uart);
mode_var = fw_getenv(mode_var_name);
if (mode_var) {
while (mode_var[0] >= '0' && mode_var[0] <= '9') {
baud *= 10;
baud += mode_var[0] - '0';
mode_var++;
}
if (mode_var[0] == ',')
mode_var++;
if (mode_var[0])
parity = mode_var[0];
if (mode_var[0] == ',')
mode_var++;
if (mode_var[0])
stop_bits = mode_var[0] - '0';
if (mode_var[0] == ',')
mode_var++;
if (!strcmp(mode_var, "hw"))
hw_flow = true;
}
if (!baud)
baud = 38400;
if (parity != 'e' && parity != 'n' && parity != 'o')
parity = 'n';
if (stop_bits != 7 && stop_bits != 8)
stop_bits = 8;
WARN_ON(snprintf(path, sizeof(path), "uart%u:%u%c%u%s",
uart, baud, parity, stop_bits,
hw_flow ? "r" : "") >= sizeof(path));
/* find or add chosen node */
chosen_off = fdt_path_offset(fdt, "/chosen");
if (chosen_off == -FDT_ERR_NOTFOUND)
chosen_off = fdt_path_offset(fdt, "/chosen@0");
if (chosen_off == -FDT_ERR_NOTFOUND)
chosen_off = fdt_add_subnode(fdt, 0, "chosen");
if (chosen_off < 0) {
pr_err("Unable to find or add DT chosen node: %d\n",
chosen_off);
return chosen_off;
}
err = fdt_setprop_string(fdt, chosen_off, "stdout-path", path);
if (err) {
pr_err("Unable to set stdout-path property: %d\n", err);
return err;
}
return 0;
}