1 /* 2 * Broadcom STB CPU SMP and hotplug support for ARM 3 * 4 * Copyright (C) 2013-2014 Broadcom Corporation 5 * 6 * This program is free software; you can redistribute it and/or 7 * modify it under the terms of the GNU General Public License as 8 * published by the Free Software Foundation version 2. 9 * 10 * This program is distributed "as is" WITHOUT ANY WARRANTY of any 11 * kind, whether express or implied; without even the implied warranty 12 * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 13 * GNU General Public License for more details. 14 */ 15 16 #include <linux/delay.h> 17 #include <linux/errno.h> 18 #include <linux/init.h> 19 #include <linux/io.h> 20 #include <linux/jiffies.h> 21 #include <linux/of_address.h> 22 #include <linux/of_platform.h> 23 #include <linux/printk.h> 24 #include <linux/regmap.h> 25 #include <linux/smp.h> 26 #include <linux/mfd/syscon.h> 27 28 #include <asm/cacheflush.h> 29 #include <asm/cp15.h> 30 #include <asm/mach-types.h> 31 #include <asm/smp_plat.h> 32 33 enum { 34 ZONE_MAN_CLKEN_MASK = BIT(0), 35 ZONE_MAN_RESET_CNTL_MASK = BIT(1), 36 ZONE_MAN_MEM_PWR_MASK = BIT(4), 37 ZONE_RESERVED_1_MASK = BIT(5), 38 ZONE_MAN_ISO_CNTL_MASK = BIT(6), 39 ZONE_MANUAL_CONTROL_MASK = BIT(7), 40 ZONE_PWR_DN_REQ_MASK = BIT(9), 41 ZONE_PWR_UP_REQ_MASK = BIT(10), 42 ZONE_BLK_RST_ASSERT_MASK = BIT(12), 43 ZONE_PWR_OFF_STATE_MASK = BIT(25), 44 ZONE_PWR_ON_STATE_MASK = BIT(26), 45 ZONE_DPG_PWR_STATE_MASK = BIT(28), 46 ZONE_MEM_PWR_STATE_MASK = BIT(29), 47 ZONE_RESET_STATE_MASK = BIT(31), 48 CPU0_PWR_ZONE_CTRL_REG = 1, 49 CPU_RESET_CONFIG_REG = 2, 50 }; 51 52 static void __iomem *cpubiuctrl_block; 53 static void __iomem *hif_cont_block; 54 static u32 cpu0_pwr_zone_ctrl_reg; 55 static u32 cpu_rst_cfg_reg; 56 static u32 hif_cont_reg; 57 58 #ifdef CONFIG_HOTPLUG_CPU 59 /* 60 * We must quiesce a dying CPU before it can be killed by the boot CPU. Because 61 * one or more cache may be disabled, we must flush to ensure coherency. We 62 * cannot use traditionl completion structures or spinlocks as they rely on 63 * coherency. 64 */ 65 static DEFINE_PER_CPU_ALIGNED(int, per_cpu_sw_state); 66 67 static int per_cpu_sw_state_rd(u32 cpu) 68 { 69 sync_cache_r(SHIFT_PERCPU_PTR(&per_cpu_sw_state, per_cpu_offset(cpu))); 70 return per_cpu(per_cpu_sw_state, cpu); 71 } 72 73 static void per_cpu_sw_state_wr(u32 cpu, int val) 74 { 75 dmb(); 76 per_cpu(per_cpu_sw_state, cpu) = val; 77 sync_cache_w(SHIFT_PERCPU_PTR(&per_cpu_sw_state, per_cpu_offset(cpu))); 78 } 79 #else 80 static inline void per_cpu_sw_state_wr(u32 cpu, int val) { } 81 #endif 82 83 static void __iomem *pwr_ctrl_get_base(u32 cpu) 84 { 85 void __iomem *base = cpubiuctrl_block + cpu0_pwr_zone_ctrl_reg; 86 base += (cpu_logical_map(cpu) * 4); 87 return base; 88 } 89 90 static u32 pwr_ctrl_rd(u32 cpu) 91 { 92 void __iomem *base = pwr_ctrl_get_base(cpu); 93 return readl_relaxed(base); 94 } 95 96 static void pwr_ctrl_set(unsigned int cpu, u32 val, u32 mask) 97 { 98 void __iomem *base = pwr_ctrl_get_base(cpu); 99 writel((readl(base) & mask) | val, base); 100 } 101 102 static void pwr_ctrl_clr(unsigned int cpu, u32 val, u32 mask) 103 { 104 void __iomem *base = pwr_ctrl_get_base(cpu); 105 writel((readl(base) & mask) & ~val, base); 106 } 107 108 #define POLL_TMOUT_MS 500 109 static int pwr_ctrl_wait_tmout(unsigned int cpu, u32 set, u32 mask) 110 { 111 const unsigned long timeo = jiffies + msecs_to_jiffies(POLL_TMOUT_MS); 112 u32 tmp; 113 114 do { 115 tmp = pwr_ctrl_rd(cpu) & mask; 116 if (!set == !tmp) 117 return 0; 118 } while (time_before(jiffies, timeo)); 119 120 tmp = pwr_ctrl_rd(cpu) & mask; 121 if (!set == !tmp) 122 return 0; 123 124 return -ETIMEDOUT; 125 } 126 127 static void cpu_rst_cfg_set(u32 cpu, int set) 128 { 129 u32 val; 130 val = readl_relaxed(cpubiuctrl_block + cpu_rst_cfg_reg); 131 if (set) 132 val |= BIT(cpu_logical_map(cpu)); 133 else 134 val &= ~BIT(cpu_logical_map(cpu)); 135 writel_relaxed(val, cpubiuctrl_block + cpu_rst_cfg_reg); 136 } 137 138 static void cpu_set_boot_addr(u32 cpu, unsigned long boot_addr) 139 { 140 const int reg_ofs = cpu_logical_map(cpu) * 8; 141 writel_relaxed(0, hif_cont_block + hif_cont_reg + reg_ofs); 142 writel_relaxed(boot_addr, hif_cont_block + hif_cont_reg + 4 + reg_ofs); 143 } 144 145 static void brcmstb_cpu_boot(u32 cpu) 146 { 147 /* Mark this CPU as "up" */ 148 per_cpu_sw_state_wr(cpu, 1); 149 150 /* 151 * Set the reset vector to point to the secondary_startup 152 * routine 153 */ 154 cpu_set_boot_addr(cpu, virt_to_phys(secondary_startup)); 155 156 /* Unhalt the cpu */ 157 cpu_rst_cfg_set(cpu, 0); 158 } 159 160 static void brcmstb_cpu_power_on(u32 cpu) 161 { 162 /* 163 * The secondary cores power was cut, so we must go through 164 * power-on initialization. 165 */ 166 pwr_ctrl_set(cpu, ZONE_MAN_ISO_CNTL_MASK, 0xffffff00); 167 pwr_ctrl_set(cpu, ZONE_MANUAL_CONTROL_MASK, -1); 168 pwr_ctrl_set(cpu, ZONE_RESERVED_1_MASK, -1); 169 170 pwr_ctrl_set(cpu, ZONE_MAN_MEM_PWR_MASK, -1); 171 172 if (pwr_ctrl_wait_tmout(cpu, 1, ZONE_MEM_PWR_STATE_MASK)) 173 panic("ZONE_MEM_PWR_STATE_MASK set timeout"); 174 175 pwr_ctrl_set(cpu, ZONE_MAN_CLKEN_MASK, -1); 176 177 if (pwr_ctrl_wait_tmout(cpu, 1, ZONE_DPG_PWR_STATE_MASK)) 178 panic("ZONE_DPG_PWR_STATE_MASK set timeout"); 179 180 pwr_ctrl_clr(cpu, ZONE_MAN_ISO_CNTL_MASK, -1); 181 pwr_ctrl_set(cpu, ZONE_MAN_RESET_CNTL_MASK, -1); 182 } 183 184 static int brcmstb_cpu_get_power_state(u32 cpu) 185 { 186 int tmp = pwr_ctrl_rd(cpu); 187 return (tmp & ZONE_RESET_STATE_MASK) ? 0 : 1; 188 } 189 190 #ifdef CONFIG_HOTPLUG_CPU 191 192 static void brcmstb_cpu_die(u32 cpu) 193 { 194 v7_exit_coherency_flush(all); 195 196 per_cpu_sw_state_wr(cpu, 0); 197 198 /* Sit and wait to die */ 199 wfi(); 200 201 /* We should never get here... */ 202 while (1) 203 ; 204 } 205 206 static int brcmstb_cpu_kill(u32 cpu) 207 { 208 /* 209 * Ordinarily, the hardware forbids power-down of CPU0 (which is good 210 * because it is the boot CPU), but this is not true when using BPCM 211 * manual mode. Consequently, we must avoid turning off CPU0 here to 212 * ensure that TI2C master reset will work. 213 */ 214 if (cpu == 0) { 215 pr_warn("SMP: refusing to power off CPU0\n"); 216 return 1; 217 } 218 219 while (per_cpu_sw_state_rd(cpu)) 220 ; 221 222 pwr_ctrl_set(cpu, ZONE_MANUAL_CONTROL_MASK, -1); 223 pwr_ctrl_clr(cpu, ZONE_MAN_RESET_CNTL_MASK, -1); 224 pwr_ctrl_clr(cpu, ZONE_MAN_CLKEN_MASK, -1); 225 pwr_ctrl_set(cpu, ZONE_MAN_ISO_CNTL_MASK, -1); 226 pwr_ctrl_clr(cpu, ZONE_MAN_MEM_PWR_MASK, -1); 227 228 if (pwr_ctrl_wait_tmout(cpu, 0, ZONE_MEM_PWR_STATE_MASK)) 229 panic("ZONE_MEM_PWR_STATE_MASK clear timeout"); 230 231 pwr_ctrl_clr(cpu, ZONE_RESERVED_1_MASK, -1); 232 233 if (pwr_ctrl_wait_tmout(cpu, 0, ZONE_DPG_PWR_STATE_MASK)) 234 panic("ZONE_DPG_PWR_STATE_MASK clear timeout"); 235 236 /* Flush pipeline before resetting CPU */ 237 mb(); 238 239 /* Assert reset on the CPU */ 240 cpu_rst_cfg_set(cpu, 1); 241 242 return 1; 243 } 244 245 #endif /* CONFIG_HOTPLUG_CPU */ 246 247 static int __init setup_hifcpubiuctrl_regs(struct device_node *np) 248 { 249 int rc = 0; 250 char *name; 251 struct device_node *syscon_np = NULL; 252 253 name = "syscon-cpu"; 254 255 syscon_np = of_parse_phandle(np, name, 0); 256 if (!syscon_np) { 257 pr_err("can't find phandle %s\n", name); 258 rc = -EINVAL; 259 goto cleanup; 260 } 261 262 cpubiuctrl_block = of_iomap(syscon_np, 0); 263 if (!cpubiuctrl_block) { 264 pr_err("iomap failed for cpubiuctrl_block\n"); 265 rc = -EINVAL; 266 goto cleanup; 267 } 268 269 rc = of_property_read_u32_index(np, name, CPU0_PWR_ZONE_CTRL_REG, 270 &cpu0_pwr_zone_ctrl_reg); 271 if (rc) { 272 pr_err("failed to read 1st entry from %s property (%d)\n", name, 273 rc); 274 rc = -EINVAL; 275 goto cleanup; 276 } 277 278 rc = of_property_read_u32_index(np, name, CPU_RESET_CONFIG_REG, 279 &cpu_rst_cfg_reg); 280 if (rc) { 281 pr_err("failed to read 2nd entry from %s property (%d)\n", name, 282 rc); 283 rc = -EINVAL; 284 goto cleanup; 285 } 286 287 cleanup: 288 of_node_put(syscon_np); 289 return rc; 290 } 291 292 static int __init setup_hifcont_regs(struct device_node *np) 293 { 294 int rc = 0; 295 char *name; 296 struct device_node *syscon_np = NULL; 297 298 name = "syscon-cont"; 299 300 syscon_np = of_parse_phandle(np, name, 0); 301 if (!syscon_np) { 302 pr_err("can't find phandle %s\n", name); 303 rc = -EINVAL; 304 goto cleanup; 305 } 306 307 hif_cont_block = of_iomap(syscon_np, 0); 308 if (!hif_cont_block) { 309 pr_err("iomap failed for hif_cont_block\n"); 310 rc = -EINVAL; 311 goto cleanup; 312 } 313 314 /* Offset is at top of hif_cont_block */ 315 hif_cont_reg = 0; 316 317 cleanup: 318 of_node_put(syscon_np); 319 return rc; 320 } 321 322 static void __init brcmstb_cpu_ctrl_setup(unsigned int max_cpus) 323 { 324 int rc; 325 struct device_node *np; 326 char *name; 327 328 name = "brcm,brcmstb-smpboot"; 329 np = of_find_compatible_node(NULL, NULL, name); 330 if (!np) { 331 pr_err("can't find compatible node %s\n", name); 332 return; 333 } 334 335 rc = setup_hifcpubiuctrl_regs(np); 336 if (rc) 337 return; 338 339 rc = setup_hifcont_regs(np); 340 if (rc) 341 return; 342 } 343 344 static int brcmstb_boot_secondary(unsigned int cpu, struct task_struct *idle) 345 { 346 /* Missing the brcm,brcmstb-smpboot DT node? */ 347 if (!cpubiuctrl_block || !hif_cont_block) 348 return -ENODEV; 349 350 /* Bring up power to the core if necessary */ 351 if (brcmstb_cpu_get_power_state(cpu) == 0) 352 brcmstb_cpu_power_on(cpu); 353 354 brcmstb_cpu_boot(cpu); 355 356 return 0; 357 } 358 359 static const struct smp_operations brcmstb_smp_ops __initconst = { 360 .smp_prepare_cpus = brcmstb_cpu_ctrl_setup, 361 .smp_boot_secondary = brcmstb_boot_secondary, 362 #ifdef CONFIG_HOTPLUG_CPU 363 .cpu_kill = brcmstb_cpu_kill, 364 .cpu_die = brcmstb_cpu_die, 365 #endif 366 }; 367 368 CPU_METHOD_OF_DECLARE(brcmstb_smp, "brcm,brahma-b15", &brcmstb_smp_ops); 369