// SPDX-License-Identifier: GPL-2.0-only
/*
* Broadcom STB CPU SMP and hotplug support for ARM
*
* Copyright (C) 2013-2014 Broadcom Corporation
*/
#include <linux/delay.h>
#include <linux/errno.h>
#include <linux/init.h>
#include <linux/io.h>
#include <linux/jiffies.h>
#include <linux/of.h>
#include <linux/of_address.h>
#include <linux/printk.h>
#include <linux/regmap.h>
#include <linux/smp.h>
#include <linux/mfd/syscon.h>
#include <asm/cacheflush.h>
#include <asm/cp15.h>
#include <asm/mach-types.h>
#include <asm/smp_plat.h>
enum {
ZONE_MAN_CLKEN_MASK = BIT(0),
ZONE_MAN_RESET_CNTL_MASK = BIT(1),
ZONE_MAN_MEM_PWR_MASK = BIT(4),
ZONE_RESERVED_1_MASK = BIT(5),
ZONE_MAN_ISO_CNTL_MASK = BIT(6),
ZONE_MANUAL_CONTROL_MASK = BIT(7),
ZONE_PWR_DN_REQ_MASK = BIT(9),
ZONE_PWR_UP_REQ_MASK = BIT(10),
ZONE_BLK_RST_ASSERT_MASK = BIT(12),
ZONE_PWR_OFF_STATE_MASK = BIT(25),
ZONE_PWR_ON_STATE_MASK = BIT(26),
ZONE_DPG_PWR_STATE_MASK = BIT(28),
ZONE_MEM_PWR_STATE_MASK = BIT(29),
ZONE_RESET_STATE_MASK = BIT(31),
CPU0_PWR_ZONE_CTRL_REG = 1,
CPU_RESET_CONFIG_REG = 2,
};
static void __iomem *cpubiuctrl_block;
static void __iomem *hif_cont_block;
static u32 cpu0_pwr_zone_ctrl_reg;
static u32 cpu_rst_cfg_reg;
static u32 hif_cont_reg;
#ifdef CONFIG_HOTPLUG_CPU
/*
* We must quiesce a dying CPU before it can be killed by the boot CPU. Because
* one or more cache may be disabled, we must flush to ensure coherency. We
* cannot use traditional completion structures or spinlocks as they rely on
* coherency.
*/
static DEFINE_PER_CPU_ALIGNED(int, per_cpu_sw_state);
static int per_cpu_sw_state_rd(u32 cpu)
{
sync_cache_r(SHIFT_PERCPU_PTR(&per_cpu_sw_state, per_cpu_offset(cpu)));
return per_cpu(per_cpu_sw_state, cpu);
}
static void per_cpu_sw_state_wr(u32 cpu, int val)
{
dmb();
per_cpu(per_cpu_sw_state, cpu) = val;
sync_cache_w(SHIFT_PERCPU_PTR(&per_cpu_sw_state, per_cpu_offset(cpu)));
}
#else
static inline void per_cpu_sw_state_wr(u32 cpu, int val) { }
#endif
static void __iomem *pwr_ctrl_get_base(u32 cpu)
{
void __iomem *base = cpubiuctrl_block + cpu0_pwr_zone_ctrl_reg;
base += (cpu_logical_map(cpu) * 4);
return base;
}
static u32 pwr_ctrl_rd(u32 cpu)
{
void __iomem *base = pwr_ctrl_get_base(cpu);
return readl_relaxed(base);
}
static void pwr_ctrl_set(unsigned int cpu, u32 val, u32 mask)
{
void __iomem *base = pwr_ctrl_get_base(cpu);
writel((readl(base) & mask) | val, base);
}
static void pwr_ctrl_clr(unsigned int cpu, u32 val, u32 mask)
{
void __iomem *base = pwr_ctrl_get_base(cpu);
writel((readl(base) & mask) & ~val, base);
}
#define POLL_TMOUT_MS 500
static int pwr_ctrl_wait_tmout(unsigned int cpu, u32 set, u32 mask)
{
const unsigned long timeo = jiffies + msecs_to_jiffies(POLL_TMOUT_MS);
u32 tmp;
do {
tmp = pwr_ctrl_rd(cpu) & mask;
if (!set == !tmp)
return 0;
} while (time_before(jiffies, timeo));
tmp = pwr_ctrl_rd(cpu) & mask;
if (!set == !tmp)
return 0;
return -ETIMEDOUT;
}
static void cpu_rst_cfg_set(u32 cpu, int set)
{
u32 val;
val = readl_relaxed(cpubiuctrl_block + cpu_rst_cfg_reg);
if (set)
val |= BIT(cpu_logical_map(cpu));
else
val &= ~BIT(cpu_logical_map(cpu));
writel_relaxed(val, cpubiuctrl_block + cpu_rst_cfg_reg);
}
static void cpu_set_boot_addr(u32 cpu, unsigned long boot_addr)
{
const int reg_ofs = cpu_logical_map(cpu) * 8;
writel_relaxed(0, hif_cont_block + hif_cont_reg + reg_ofs);
writel_relaxed(boot_addr, hif_cont_block + hif_cont_reg + 4 + reg_ofs);
}
static void brcmstb_cpu_boot(u32 cpu)
{
/* Mark this CPU as "up" */
per_cpu_sw_state_wr(cpu, 1);
/*
* Set the reset vector to point to the secondary_startup
* routine
*/
cpu_set_boot_addr(cpu, __pa_symbol(secondary_startup));
/* Unhalt the cpu */
cpu_rst_cfg_set(cpu, 0);
}
static void brcmstb_cpu_power_on(u32 cpu)
{
/*
* The secondary cores power was cut, so we must go through
* power-on initialization.
*/
pwr_ctrl_set(cpu, ZONE_MAN_ISO_CNTL_MASK, 0xffffff00);
pwr_ctrl_set(cpu, ZONE_MANUAL_CONTROL_MASK, -1);
pwr_ctrl_set(cpu, ZONE_RESERVED_1_MASK, -1);
pwr_ctrl_set(cpu, ZONE_MAN_MEM_PWR_MASK, -1);
if (pwr_ctrl_wait_tmout(cpu, 1, ZONE_MEM_PWR_STATE_MASK))
panic("ZONE_MEM_PWR_STATE_MASK set timeout");
pwr_ctrl_set(cpu, ZONE_MAN_CLKEN_MASK, -1);
if (pwr_ctrl_wait_tmout(cpu, 1, ZONE_DPG_PWR_STATE_MASK))
panic("ZONE_DPG_PWR_STATE_MASK set timeout");
pwr_ctrl_clr(cpu, ZONE_MAN_ISO_CNTL_MASK, -1);
pwr_ctrl_set(cpu, ZONE_MAN_RESET_CNTL_MASK, -1);
}
static int brcmstb_cpu_get_power_state(u32 cpu)
{
int tmp = pwr_ctrl_rd(cpu);
return (tmp & ZONE_RESET_STATE_MASK) ? 0 : 1;
}
#ifdef CONFIG_HOTPLUG_CPU
static void brcmstb_cpu_die(u32 cpu)
{
v7_exit_coherency_flush(all);
per_cpu_sw_state_wr(cpu, 0);
/* Sit and wait to die */
wfi();
/* We should never get here... */
while (1)
;
}
static int brcmstb_cpu_kill(u32 cpu)
{
/*
* Ordinarily, the hardware forbids power-down of CPU0 (which is good
* because it is the boot CPU), but this is not true when using BPCM
* manual mode. Consequently, we must avoid turning off CPU0 here to
* ensure that TI2C master reset will work.
*/
if (cpu == 0) {
pr_warn("SMP: refusing to power off CPU0\n");
return 1;
}
while (per_cpu_sw_state_rd(cpu))
;
pwr_ctrl_set(cpu, ZONE_MANUAL_CONTROL_MASK, -1);
pwr_ctrl_clr(cpu, ZONE_MAN_RESET_CNTL_MASK, -1);
pwr_ctrl_clr(cpu, ZONE_MAN_CLKEN_MASK, -1);
pwr_ctrl_set(cpu, ZONE_MAN_ISO_CNTL_MASK, -1);
pwr_ctrl_clr(cpu, ZONE_MAN_MEM_PWR_MASK, -1);
if (pwr_ctrl_wait_tmout(cpu, 0, ZONE_MEM_PWR_STATE_MASK))
panic("ZONE_MEM_PWR_STATE_MASK clear timeout");
pwr_ctrl_clr(cpu, ZONE_RESERVED_1_MASK, -1);
if (pwr_ctrl_wait_tmout(cpu, 0, ZONE_DPG_PWR_STATE_MASK))
panic("ZONE_DPG_PWR_STATE_MASK clear timeout");
/* Flush pipeline before resetting CPU */
mb();
/* Assert reset on the CPU */
cpu_rst_cfg_set(cpu, 1);
return 1;
}
#endif /* CONFIG_HOTPLUG_CPU */
static int __init setup_hifcpubiuctrl_regs(struct device_node *np)
{
int rc = 0;
char *name;
struct device_node *syscon_np = NULL;
name = "syscon-cpu";
syscon_np = of_parse_phandle(np, name, 0);
if (!syscon_np) {
pr_err("can't find phandle %s\n", name);
rc = -EINVAL;
goto cleanup;
}
cpubiuctrl_block = of_iomap(syscon_np, 0);
if (!cpubiuctrl_block) {
pr_err("iomap failed for cpubiuctrl_block\n");
rc = -EINVAL;
goto cleanup;
}
rc = of_property_read_u32_index(np, name, CPU0_PWR_ZONE_CTRL_REG,
&cpu0_pwr_zone_ctrl_reg);
if (rc) {
pr_err("failed to read 1st entry from %s property (%d)\n", name,
rc);
rc = -EINVAL;
goto cleanup;
}
rc = of_property_read_u32_index(np, name, CPU_RESET_CONFIG_REG,
&cpu_rst_cfg_reg);
if (rc) {
pr_err("failed to read 2nd entry from %s property (%d)\n", name,
rc);
rc = -EINVAL;
goto cleanup;
}
cleanup:
of_node_put(syscon_np);
return rc;
}
static int __init setup_hifcont_regs(struct device_node *np)
{
int rc = 0;
char *name;
struct device_node *syscon_np = NULL;
name = "syscon-cont";
syscon_np = of_parse_phandle(np, name, 0);
if (!syscon_np) {
pr_err("can't find phandle %s\n", name);
rc = -EINVAL;
goto cleanup;
}
hif_cont_block = of_iomap(syscon_np, 0);
if (!hif_cont_block) {
pr_err("iomap failed for hif_cont_block\n");
rc = -EINVAL;
goto cleanup;
}
/* Offset is at top of hif_cont_block */
hif_cont_reg = 0;
cleanup:
of_node_put(syscon_np);
return rc;
}
static void __init brcmstb_cpu_ctrl_setup(unsigned int max_cpus)
{
int rc;
struct device_node *np;
char *name;
name = "brcm,brcmstb-smpboot";
np = of_find_compatible_node(NULL, NULL, name);
if (!np) {
pr_err("can't find compatible node %s\n", name);
return;
}
rc = setup_hifcpubiuctrl_regs(np);
if (rc)
goto out_put_node;
rc = setup_hifcont_regs(np);
if (rc)
goto out_put_node;
out_put_node:
of_node_put(np);
}
static int brcmstb_boot_secondary(unsigned int cpu, struct task_struct *idle)
{
/* Missing the brcm,brcmstb-smpboot DT node? */
if (!cpubiuctrl_block || !hif_cont_block)
return -ENODEV;
/* Bring up power to the core if necessary */
if (brcmstb_cpu_get_power_state(cpu) == 0)
brcmstb_cpu_power_on(cpu);
brcmstb_cpu_boot(cpu);
return 0;
}
static const struct smp_operations brcmstb_smp_ops __initconst = {
.smp_prepare_cpus = brcmstb_cpu_ctrl_setup,
.smp_boot_secondary = brcmstb_boot_secondary,
#ifdef CONFIG_HOTPLUG_CPU
.cpu_kill = brcmstb_cpu_kill,
.cpu_die = brcmstb_cpu_die,
#endif
};
CPU_METHOD_OF_DECLARE(brcmstb_smp, "brcm,brahma-b15", &brcmstb_smp_ops);
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