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/*
* Copyright (C) 2015 Masahiro Yamada <yamada.masahiro@socionext.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.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*/
#define pr_fmt(fmt) "uniphier: " fmt
#include <linux/init.h>
#include <linux/io.h>
#include <linux/ioport.h>
#include <linux/of.h>
#include <linux/of_address.h>
#include <linux/sizes.h>
#include <asm/cacheflush.h>
#include <asm/hardware/cache-uniphier.h>
#include <asm/pgtable.h>
#include <asm/smp.h>
#include <asm/smp_scu.h>
/*
* The secondary CPUs check this register from the boot ROM for the jump
* destination. After that, it can be reused as a scratch register.
*/
#define UNIPHIER_SBC_ROM_BOOT_RSV2 0x1208
static void __iomem *uniphier_smp_rom_boot_rsv2;
static unsigned int uniphier_smp_max_cpus;
extern char uniphier_smp_trampoline;
extern char uniphier_smp_trampoline_jump;
extern char uniphier_smp_trampoline_poll_addr;
extern char uniphier_smp_trampoline_end;
/*
* Copy trampoline code to the tail of the 1st section of the page table used
* in the boot ROM. This area is directly accessible by the secondary CPUs
* for all the UniPhier SoCs.
*/
static const phys_addr_t uniphier_smp_trampoline_dest_end = SECTION_SIZE;
static phys_addr_t uniphier_smp_trampoline_dest;
static int __init uniphier_smp_copy_trampoline(phys_addr_t poll_addr)
{
size_t trmp_size;
static void __iomem *trmp_base;
if (!uniphier_cache_l2_is_enabled()) {
pr_warn("outer cache is needed for SMP, but not enabled\n");
return -ENODEV;
}
uniphier_cache_l2_set_locked_ways(1);
outer_flush_all();
trmp_size = &uniphier_smp_trampoline_end - &uniphier_smp_trampoline;
uniphier_smp_trampoline_dest = uniphier_smp_trampoline_dest_end -
trmp_size;
uniphier_cache_l2_touch_range(uniphier_smp_trampoline_dest,
uniphier_smp_trampoline_dest_end);
trmp_base = ioremap_cache(uniphier_smp_trampoline_dest, trmp_size);
if (!trmp_base) {
pr_err("failed to map trampoline destination area\n");
return -ENOMEM;
}
memcpy(trmp_base, &uniphier_smp_trampoline, trmp_size);
writel(virt_to_phys(secondary_startup),
trmp_base + (&uniphier_smp_trampoline_jump -
&uniphier_smp_trampoline));
writel(poll_addr, trmp_base + (&uniphier_smp_trampoline_poll_addr -
&uniphier_smp_trampoline));
flush_cache_all(); /* flush out trampoline code to outer cache */
iounmap(trmp_base);
return 0;
}
static int __init uniphier_smp_prepare_trampoline(unsigned int max_cpus)
{
struct device_node *np;
struct resource res;
phys_addr_t rom_rsv2_phys;
int ret;
np = of_find_compatible_node(NULL, NULL,
"socionext,uniphier-system-bus-controller");
ret = of_address_to_resource(np, 1, &res);
if (ret) {
pr_err("failed to get resource of system-bus-controller\n");
return ret;
}
rom_rsv2_phys = res.start + UNIPHIER_SBC_ROM_BOOT_RSV2;
ret = uniphier_smp_copy_trampoline(rom_rsv2_phys);
if (ret)
return ret;
uniphier_smp_rom_boot_rsv2 = ioremap(rom_rsv2_phys, sizeof(SZ_4));
if (!uniphier_smp_rom_boot_rsv2) {
pr_err("failed to map ROM_BOOT_RSV2 register\n");
return -ENOMEM;
}
writel(uniphier_smp_trampoline_dest, uniphier_smp_rom_boot_rsv2);
asm("sev"); /* Bring up all secondary CPUs to the trampoline code */
uniphier_smp_max_cpus = max_cpus; /* save for later use */
return 0;
}
static void __init uniphier_smp_unprepare_trampoline(void)
{
iounmap(uniphier_smp_rom_boot_rsv2);
if (uniphier_smp_trampoline_dest)
outer_inv_range(uniphier_smp_trampoline_dest,
uniphier_smp_trampoline_dest_end);
uniphier_cache_l2_set_locked_ways(0);
}
static int __init uniphier_smp_enable_scu(void)
{
unsigned long scu_base_phys = 0;
void __iomem *scu_base;
if (scu_a9_has_base())
scu_base_phys = scu_a9_get_base();
if (!scu_base_phys) {
pr_err("failed to get scu base\n");
return -ENODEV;
}
scu_base = ioremap(scu_base_phys, SZ_128);
if (!scu_base) {
pr_err("failed to map scu base\n");
return -ENOMEM;
}
scu_enable(scu_base);
iounmap(scu_base);
return 0;
}
static void __init uniphier_smp_prepare_cpus(unsigned int max_cpus)
{
static cpumask_t only_cpu_0 = { CPU_BITS_CPU0 };
int ret;
ret = uniphier_smp_prepare_trampoline(max_cpus);
if (ret)
goto err;
ret = uniphier_smp_enable_scu();
if (ret)
goto err;
return;
err:
pr_warn("disabling SMP\n");
init_cpu_present(&only_cpu_0);
uniphier_smp_unprepare_trampoline();
}
static int __init uniphier_smp_boot_secondary(unsigned int cpu,
struct task_struct *idle)
{
if (WARN_ON_ONCE(!uniphier_smp_rom_boot_rsv2))
return -EFAULT;
writel(cpu, uniphier_smp_rom_boot_rsv2);
readl(uniphier_smp_rom_boot_rsv2); /* relax */
asm("sev"); /* wake up secondary CPUs sleeping in the trampoline */
if (cpu == uniphier_smp_max_cpus - 1) {
/* clean up resources if this is the last CPU */
uniphier_smp_unprepare_trampoline();
}
return 0;
}
static const struct smp_operations uniphier_smp_ops __initconst = {
.smp_prepare_cpus = uniphier_smp_prepare_cpus,
.smp_boot_secondary = uniphier_smp_boot_secondary,
};
CPU_METHOD_OF_DECLARE(uniphier_smp, "socionext,uniphier-smp",
&uniphier_smp_ops);
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