| /* |
| * 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 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); |