diff options
Diffstat (limited to 'arch/arm/mach-bcm/platsmp-brcmstb.c')
| -rw-r--r-- | arch/arm/mach-bcm/platsmp-brcmstb.c | 368 |
1 files changed, 368 insertions, 0 deletions
diff --git a/arch/arm/mach-bcm/platsmp-brcmstb.c b/arch/arm/mach-bcm/platsmp-brcmstb.c new file mode 100644 index 000000000..12379960e --- /dev/null +++ b/arch/arm/mach-bcm/platsmp-brcmstb.c @@ -0,0 +1,368 @@ +/* + * Broadcom STB CPU SMP and hotplug support for ARM + * + * Copyright (C) 2013-2014 Broadcom Corporation + * + * 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 version 2. + * + * This program is distributed "as is" WITHOUT ANY WARRANTY of any + * kind, whether express or implied; without even the implied warranty + * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + */ + +#include <linux/delay.h> +#include <linux/errno.h> +#include <linux/init.h> +#include <linux/io.h> +#include <linux/jiffies.h> +#include <linux/of_address.h> +#include <linux/of_platform.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 traditionl 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) + return; + + rc = setup_hifcont_regs(np); + if (rc) + return; +} + +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); |