arch/arm/mach-sunxi/mc_smp.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Copyright (c) 2018 Chen-Yu Tsai
   4  *
   5  * Chen-Yu Tsai <wens@csie.org>
   6  *
   7  * arch/arm/mach-sunxi/mc_smp.c
   8  *
   9  * Based on Allwinner code, arch/arm/mach-exynos/mcpm-exynos.c, and
  10  * arch/arm/mach-hisi/platmcpm.c
  11  * Cluster cache enable trampoline code adapted from MCPM framework
  12  */
  13
  14 #include <linux/arm-cci.h>
  15 #include <linux/cpu_pm.h>
  16 #include <linux/delay.h>
  17 #include <linux/io.h>
  18 #include <linux/iopoll.h>
  19 #include <linux/irqchip/arm-gic.h>
  20 #include <linux/of.h>
  21 #include <linux/of_address.h>
  22 #include <linux/of_device.h>
  23 #include <linux/smp.h>
  24
  25 #include <asm/cacheflush.h>
  26 #include <asm/cp15.h>
  27 #include <asm/cputype.h>
  28 #include <asm/idmap.h>
  29 #include <asm/smp_plat.h>
  30 #include <asm/suspend.h>
  31
  32 #define SUNXI_CPUS_PER_CLUSTER          4
  33 #define SUNXI_NR_CLUSTERS               2
  34
  35 #define POLL_USEC       100
  36 #define TIMEOUT_USEC    100000
  37
  38 #define CPUCFG_CX_CTRL_REG0(c)          (0x10 * (c))
  39 #define CPUCFG_CX_CTRL_REG0_L1_RST_DISABLE(n)   BIT(n)
  40 #define CPUCFG_CX_CTRL_REG0_L1_RST_DISABLE_ALL  0xf
  41 #define CPUCFG_CX_CTRL_REG0_L2_RST_DISABLE_A7   BIT(4)
  42 #define CPUCFG_CX_CTRL_REG0_L2_RST_DISABLE_A15  BIT(0)
  43 #define CPUCFG_CX_CTRL_REG1(c)          (0x10 * (c) + 0x4)
  44 #define CPUCFG_CX_CTRL_REG1_ACINACTM    BIT(0)
  45 #define CPUCFG_CX_STATUS(c)             (0x30 + 0x4 * (c))
  46 #define CPUCFG_CX_STATUS_STANDBYWFI(n)  BIT(16 + (n))
  47 #define CPUCFG_CX_STATUS_STANDBYWFIL2   BIT(0)
  48 #define CPUCFG_CX_RST_CTRL(c)           (0x80 + 0x4 * (c))
  49 #define CPUCFG_CX_RST_CTRL_DBG_SOC_RST  BIT(24)
  50 #define CPUCFG_CX_RST_CTRL_ETM_RST(n)   BIT(20 + (n))
  51 #define CPUCFG_CX_RST_CTRL_ETM_RST_ALL  (0xf << 20)
  52 #define CPUCFG_CX_RST_CTRL_DBG_RST(n)   BIT(16 + (n))
  53 #define CPUCFG_CX_RST_CTRL_DBG_RST_ALL  (0xf << 16)
  54 #define CPUCFG_CX_RST_CTRL_H_RST        BIT(12)
  55 #define CPUCFG_CX_RST_CTRL_L2_RST       BIT(8)
  56 #define CPUCFG_CX_RST_CTRL_CX_RST(n)    BIT(4 + (n))
  57 #define CPUCFG_CX_RST_CTRL_CORE_RST(n)  BIT(n)
  58 #define CPUCFG_CX_RST_CTRL_CORE_RST_ALL (0xf << 0)
  59
  60 #define PRCM_CPU_PO_RST_CTRL(c)         (0x4 + 0x4 * (c))
  61 #define PRCM_CPU_PO_RST_CTRL_CORE(n)    BIT(n)
  62 #define PRCM_CPU_PO_RST_CTRL_CORE_ALL   0xf
  63 #define PRCM_PWROFF_GATING_REG(c)       (0x100 + 0x4 * (c))
  64 /* The power off register for clusters are different from a80 and a83t */
  65 #define PRCM_PWROFF_GATING_REG_CLUSTER_SUN8I    BIT(0)
  66 #define PRCM_PWROFF_GATING_REG_CLUSTER_SUN9I    BIT(4)
  67 #define PRCM_PWROFF_GATING_REG_CORE(n)  BIT(n)
  68 #define PRCM_PWR_SWITCH_REG(c, cpu)     (0x140 + 0x10 * (c) + 0x4 * (cpu))
  69 #define PRCM_CPU_SOFT_ENTRY_REG         0x164
  70
  71 /* R_CPUCFG registers, specific to sun8i-a83t */
  72 #define R_CPUCFG_CLUSTER_PO_RST_CTRL(c) (0x30 + (c) * 0x4)
  73 #define R_CPUCFG_CLUSTER_PO_RST_CTRL_CORE(n)    BIT(n)
  74 #define R_CPUCFG_CPU_SOFT_ENTRY_REG             0x01a4
  75
  76 #define CPU0_SUPPORT_HOTPLUG_MAGIC0     0xFA50392F
  77 #define CPU0_SUPPORT_HOTPLUG_MAGIC1     0x790DCA3A
  78
  79 static void __iomem *cpucfg_base;
  80 static void __iomem *prcm_base;
  81 static void __iomem *sram_b_smp_base;
  82 static void __iomem *r_cpucfg_base;
  83
  84 extern void sunxi_mc_smp_secondary_startup(void);
  85 extern void sunxi_mc_smp_resume(void);
  86 static bool is_a83t;
  87
  88 static bool sunxi_core_is_cortex_a15(unsigned int core, unsigned int cluster)
  89 {
  90         struct device_node *node;
  91         int cpu = cluster * SUNXI_CPUS_PER_CLUSTER + core;
  92         bool is_compatible;
  93
  94         node = of_cpu_device_node_get(cpu);
  95
  96         /* In case of_cpu_device_node_get fails */
  97         if (!node)
  98                 node = of_get_cpu_node(cpu, NULL);
  99
 100         if (!node) {
 101                 /*
 102                  * There's no point in returning an error, since we
 103                  * would be mid way in a core or cluster power sequence.
 104                  */
 105                 pr_err("%s: Couldn't get CPU cluster %u core %u device node\n",
 106                        __func__, cluster, core);
 107
 108                 return false;
 109         }
 110
 111         is_compatible = of_device_is_compatible(node, "arm,cortex-a15");
 112         of_node_put(node);
 113         return is_compatible;
 114 }
 115
 116 static int sunxi_cpu_power_switch_set(unsigned int cpu, unsigned int cluster,
 117                                       bool enable)
 118 {
 119         u32 reg;
 120
 121         /* control sequence from Allwinner A80 user manual v1.2 PRCM section */
 122         reg = readl(prcm_base + PRCM_PWR_SWITCH_REG(cluster, cpu));
 123         if (enable) {
 124                 if (reg == 0x00) {
 125                         pr_debug("power clamp for cluster %u cpu %u already open\n",
 126                                  cluster, cpu);
 127                         return 0;
 128                 }
 129
 130                 writel(0xff, prcm_base + PRCM_PWR_SWITCH_REG(cluster, cpu));
 131                 udelay(10);
 132                 writel(0xfe, prcm_base + PRCM_PWR_SWITCH_REG(cluster, cpu));
 133                 udelay(10);
 134                 writel(0xf8, prcm_base + PRCM_PWR_SWITCH_REG(cluster, cpu));
 135                 udelay(10);
 136                 writel(0xf0, prcm_base + PRCM_PWR_SWITCH_REG(cluster, cpu));
 137                 udelay(10);
 138                 writel(0x00, prcm_base + PRCM_PWR_SWITCH_REG(cluster, cpu));
 139                 udelay(10);
 140         } else {
 141                 writel(0xff, prcm_base + PRCM_PWR_SWITCH_REG(cluster, cpu));
 142                 udelay(10);
 143         }
 144
 145         return 0;
 146 }
 147
 148 static void sunxi_cpu0_hotplug_support_set(bool enable)
 149 {
 150         if (enable) {
 151                 writel(CPU0_SUPPORT_HOTPLUG_MAGIC0, sram_b_smp_base);
 152                 writel(CPU0_SUPPORT_HOTPLUG_MAGIC1, sram_b_smp_base + 0x4);
 153         } else {
 154                 writel(0x0, sram_b_smp_base);
 155                 writel(0x0, sram_b_smp_base + 0x4);
 156         }
 157 }
 158
 159 static int sunxi_cpu_powerup(unsigned int cpu, unsigned int cluster)
 160 {
 161         u32 reg;
 162
 163         pr_debug("%s: cluster %u cpu %u\n", __func__, cluster, cpu);
 164         if (cpu >= SUNXI_CPUS_PER_CLUSTER || cluster >= SUNXI_NR_CLUSTERS)
 165                 return -EINVAL;
 166
 167         /* Set hotplug support magic flags for cpu0 */
 168         if (cluster == 0 && cpu == 0)
 169                 sunxi_cpu0_hotplug_support_set(true);
 170
 171         /* assert processor power-on reset */
 172         reg = readl(prcm_base + PRCM_CPU_PO_RST_CTRL(cluster));
 173         reg &= ~PRCM_CPU_PO_RST_CTRL_CORE(cpu);
 174         writel(reg, prcm_base + PRCM_CPU_PO_RST_CTRL(cluster));
 175
 176         if (is_a83t) {
 177                 /* assert cpu power-on reset */
 178                 reg  = readl(r_cpucfg_base +
 179                              R_CPUCFG_CLUSTER_PO_RST_CTRL(cluster));
 180                 reg &= ~(R_CPUCFG_CLUSTER_PO_RST_CTRL_CORE(cpu));
 181                 writel(reg, r_cpucfg_base +
 182                        R_CPUCFG_CLUSTER_PO_RST_CTRL(cluster));
 183                 udelay(10);
 184         }
 185
 186         /* Cortex-A7: hold L1 reset disable signal low */
 187         if (!sunxi_core_is_cortex_a15(cpu, cluster)) {
 188                 reg = readl(cpucfg_base + CPUCFG_CX_CTRL_REG0(cluster));
 189                 reg &= ~CPUCFG_CX_CTRL_REG0_L1_RST_DISABLE(cpu);
 190                 writel(reg, cpucfg_base + CPUCFG_CX_CTRL_REG0(cluster));
 191         }
 192
 193         /* assert processor related resets */
 194         reg = readl(cpucfg_base + CPUCFG_CX_RST_CTRL(cluster));
 195         reg &= ~CPUCFG_CX_RST_CTRL_DBG_RST(cpu);
 196
 197         /*
 198          * Allwinner code also asserts resets for NEON on A15. According
 199          * to ARM manuals, asserting power-on reset is sufficient.
 200          */
 201         if (!sunxi_core_is_cortex_a15(cpu, cluster))
 202                 reg &= ~CPUCFG_CX_RST_CTRL_ETM_RST(cpu);
 203
 204         writel(reg, cpucfg_base + CPUCFG_CX_RST_CTRL(cluster));
 205
 206         /* open power switch */
 207         sunxi_cpu_power_switch_set(cpu, cluster, true);
 208
 209         /* Handle A83T bit swap */
 210         if (is_a83t) {
 211                 if (cpu == 0)
 212                         cpu = 4;
 213         }
 214
 215         /* clear processor power gate */
 216         reg = readl(prcm_base + PRCM_PWROFF_GATING_REG(cluster));
 217         reg &= ~PRCM_PWROFF_GATING_REG_CORE(cpu);
 218         writel(reg, prcm_base + PRCM_PWROFF_GATING_REG(cluster));
 219         udelay(20);
 220
 221         /* Handle A83T bit swap */
 222         if (is_a83t) {
 223                 if (cpu == 4)
 224                         cpu = 0;
 225         }
 226
 227         /* de-assert processor power-on reset */
 228         reg = readl(prcm_base + PRCM_CPU_PO_RST_CTRL(cluster));
 229         reg |= PRCM_CPU_PO_RST_CTRL_CORE(cpu);
 230         writel(reg, prcm_base + PRCM_CPU_PO_RST_CTRL(cluster));
 231
 232         if (is_a83t) {
 233                 reg  = readl(r_cpucfg_base +
 234                              R_CPUCFG_CLUSTER_PO_RST_CTRL(cluster));
 235                 reg |= R_CPUCFG_CLUSTER_PO_RST_CTRL_CORE(cpu);
 236                 writel(reg, r_cpucfg_base +
 237                        R_CPUCFG_CLUSTER_PO_RST_CTRL(cluster));
 238                 udelay(10);
 239         }
 240
 241         /* de-assert all processor resets */
 242         reg = readl(cpucfg_base + CPUCFG_CX_RST_CTRL(cluster));
 243         reg |= CPUCFG_CX_RST_CTRL_DBG_RST(cpu);
 244         reg |= CPUCFG_CX_RST_CTRL_CORE_RST(cpu);
 245         if (!sunxi_core_is_cortex_a15(cpu, cluster))
 246                 reg |= CPUCFG_CX_RST_CTRL_ETM_RST(cpu);
 247         else
 248                 reg |= CPUCFG_CX_RST_CTRL_CX_RST(cpu); /* NEON */
 249         writel(reg, cpucfg_base + CPUCFG_CX_RST_CTRL(cluster));
 250
 251         return 0;
 252 }
 253
 254 static int sunxi_cluster_powerup(unsigned int cluster)
 255 {
 256         u32 reg;
 257
 258         pr_debug("%s: cluster %u\n", __func__, cluster);
 259         if (cluster >= SUNXI_NR_CLUSTERS)
 260                 return -EINVAL;
 261
 262         /* For A83T, assert cluster cores resets */
 263         if (is_a83t) {
 264                 reg = readl(cpucfg_base + CPUCFG_CX_RST_CTRL(cluster));
 265                 reg &= ~CPUCFG_CX_RST_CTRL_CORE_RST_ALL;   /* Core Reset    */
 266                 writel(reg, cpucfg_base + CPUCFG_CX_RST_CTRL(cluster));
 267                 udelay(10);
 268         }
 269
 270         /* assert ACINACTM */
 271         reg = readl(cpucfg_base + CPUCFG_CX_CTRL_REG1(cluster));
 272         reg |= CPUCFG_CX_CTRL_REG1_ACINACTM;
 273         writel(reg, cpucfg_base + CPUCFG_CX_CTRL_REG1(cluster));
 274
 275         /* assert cluster processor power-on resets */
 276         reg = readl(prcm_base + PRCM_CPU_PO_RST_CTRL(cluster));
 277         reg &= ~PRCM_CPU_PO_RST_CTRL_CORE_ALL;
 278         writel(reg, prcm_base + PRCM_CPU_PO_RST_CTRL(cluster));
 279
 280         /* assert cluster cores resets */
 281         if (is_a83t) {
 282                 reg  = readl(r_cpucfg_base +
 283                              R_CPUCFG_CLUSTER_PO_RST_CTRL(cluster));
 284                 reg &= ~CPUCFG_CX_RST_CTRL_CORE_RST_ALL;
 285                 writel(reg, r_cpucfg_base +
 286                        R_CPUCFG_CLUSTER_PO_RST_CTRL(cluster));
 287                 udelay(10);
 288         }
 289
 290         /* assert cluster resets */
 291         reg = readl(cpucfg_base + CPUCFG_CX_RST_CTRL(cluster));
 292         reg &= ~CPUCFG_CX_RST_CTRL_DBG_SOC_RST;
 293         reg &= ~CPUCFG_CX_RST_CTRL_DBG_RST_ALL;
 294         reg &= ~CPUCFG_CX_RST_CTRL_H_RST;
 295         reg &= ~CPUCFG_CX_RST_CTRL_L2_RST;
 296
 297         /*
 298          * Allwinner code also asserts resets for NEON on A15. According
 299          * to ARM manuals, asserting power-on reset is sufficient.
 300          */
 301         if (!sunxi_core_is_cortex_a15(0, cluster))
 302                 reg &= ~CPUCFG_CX_RST_CTRL_ETM_RST_ALL;
 303
 304         writel(reg, cpucfg_base + CPUCFG_CX_RST_CTRL(cluster));
 305
 306         /* hold L1/L2 reset disable signals low */
 307         reg = readl(cpucfg_base + CPUCFG_CX_CTRL_REG0(cluster));
 308         if (sunxi_core_is_cortex_a15(0, cluster)) {
 309                 /* Cortex-A15: hold L2RSTDISABLE low */
 310                 reg &= ~CPUCFG_CX_CTRL_REG0_L2_RST_DISABLE_A15;
 311         } else {
 312                 /* Cortex-A7: hold L1RSTDISABLE and L2RSTDISABLE low */
 313                 reg &= ~CPUCFG_CX_CTRL_REG0_L1_RST_DISABLE_ALL;
 314                 reg &= ~CPUCFG_CX_CTRL_REG0_L2_RST_DISABLE_A7;
 315         }
 316         writel(reg, cpucfg_base + CPUCFG_CX_CTRL_REG0(cluster));
 317
 318         /* clear cluster power gate */
 319         reg = readl(prcm_base + PRCM_PWROFF_GATING_REG(cluster));
 320         if (is_a83t)
 321                 reg &= ~PRCM_PWROFF_GATING_REG_CLUSTER_SUN8I;
 322         else
 323                 reg &= ~PRCM_PWROFF_GATING_REG_CLUSTER_SUN9I;
 324         writel(reg, prcm_base + PRCM_PWROFF_GATING_REG(cluster));
 325         udelay(20);
 326
 327         /* de-assert cluster resets */
 328         reg = readl(cpucfg_base + CPUCFG_CX_RST_CTRL(cluster));
 329         reg |= CPUCFG_CX_RST_CTRL_DBG_SOC_RST;
 330         reg |= CPUCFG_CX_RST_CTRL_H_RST;
 331         reg |= CPUCFG_CX_RST_CTRL_L2_RST;
 332         writel(reg, cpucfg_base + CPUCFG_CX_RST_CTRL(cluster));
 333
 334         /* de-assert ACINACTM */
 335         reg = readl(cpucfg_base + CPUCFG_CX_CTRL_REG1(cluster));
 336         reg &= ~CPUCFG_CX_CTRL_REG1_ACINACTM;
 337         writel(reg, cpucfg_base + CPUCFG_CX_CTRL_REG1(cluster));
 338
 339         return 0;
 340 }
 341
 342 /*
 343  * This bit is shared between the initial nocache_trampoline call to
 344  * enable CCI-400 and proper cluster cache disable before power down.
 345  */
 346 static void sunxi_cluster_cache_disable_without_axi(void)
 347 {
 348         if (read_cpuid_part() == ARM_CPU_PART_CORTEX_A15) {
 349                 /*
 350                  * On the Cortex-A15 we need to disable
 351                  * L2 prefetching before flushing the cache.
 352                  */
 353                 asm volatile(
 354                 "mcr    p15, 1, %0, c15, c0, 3\n"
 355                 "isb\n"
 356                 "dsb"
 357                 : : "r" (0x400));
 358         }
 359
 360         /* Flush all cache levels for this cluster. */
 361         v7_exit_coherency_flush(all);
 362
 363         /*
 364          * Disable cluster-level coherency by masking
 365          * incoming snoops and DVM messages:
 366          */
 367         cci_disable_port_by_cpu(read_cpuid_mpidr());
 368 }
 369
 370 static int sunxi_mc_smp_cpu_table[SUNXI_NR_CLUSTERS][SUNXI_CPUS_PER_CLUSTER];
 371 int sunxi_mc_smp_first_comer;
 372
 373 static DEFINE_SPINLOCK(boot_lock);
 374
 375 static bool sunxi_mc_smp_cluster_is_down(unsigned int cluster)
 376 {
 377         int i;
 378
 379         for (i = 0; i < SUNXI_CPUS_PER_CLUSTER; i++)
 380                 if (sunxi_mc_smp_cpu_table[cluster][i])
 381                         return false;
 382         return true;
 383 }
 384
 385 static void sunxi_mc_smp_secondary_init(unsigned int cpu)
 386 {
 387         /* Clear hotplug support magic flags for cpu0 */
 388         if (cpu == 0)
 389                 sunxi_cpu0_hotplug_support_set(false);
 390 }
 391
 392 static int sunxi_mc_smp_boot_secondary(unsigned int l_cpu, struct task_struct *idle)
 393 {
 394         unsigned int mpidr, cpu, cluster;
 395
 396         mpidr = cpu_logical_map(l_cpu);
 397         cpu = MPIDR_AFFINITY_LEVEL(mpidr, 0);
 398         cluster = MPIDR_AFFINITY_LEVEL(mpidr, 1);
 399
 400         if (!cpucfg_base)
 401                 return -ENODEV;
 402         if (cluster >= SUNXI_NR_CLUSTERS || cpu >= SUNXI_CPUS_PER_CLUSTER)
 403                 return -EINVAL;
 404
 405         spin_lock_irq(&boot_lock);
 406
 407         if (sunxi_mc_smp_cpu_table[cluster][cpu])
 408                 goto out;
 409
 410         if (sunxi_mc_smp_cluster_is_down(cluster)) {
 411                 sunxi_mc_smp_first_comer = true;
 412                 sunxi_cluster_powerup(cluster);
 413         } else {
 414                 sunxi_mc_smp_first_comer = false;
 415         }
 416
 417         /* This is read by incoming CPUs with their cache and MMU disabled */
 418         sync_cache_w(&sunxi_mc_smp_first_comer);
 419         sunxi_cpu_powerup(cpu, cluster);
 420
 421 out:
 422         sunxi_mc_smp_cpu_table[cluster][cpu]++;
 423         spin_unlock_irq(&boot_lock);
 424
 425         return 0;
 426 }
 427
 428 #ifdef CONFIG_HOTPLUG_CPU
 429 static void sunxi_cluster_cache_disable(void)
 430 {
 431         unsigned int cluster = MPIDR_AFFINITY_LEVEL(read_cpuid_mpidr(), 1);
 432         u32 reg;
 433
 434         pr_debug("%s: cluster %u\n", __func__, cluster);
 435
 436         sunxi_cluster_cache_disable_without_axi();
 437
 438         /* last man standing, assert ACINACTM */
 439         reg = readl(cpucfg_base + CPUCFG_CX_CTRL_REG1(cluster));
 440         reg |= CPUCFG_CX_CTRL_REG1_ACINACTM;
 441         writel(reg, cpucfg_base + CPUCFG_CX_CTRL_REG1(cluster));
 442 }
 443
 444 static void sunxi_mc_smp_cpu_die(unsigned int l_cpu)
 445 {
 446         unsigned int mpidr, cpu, cluster;
 447         bool last_man;
 448
 449         mpidr = cpu_logical_map(l_cpu);
 450         cpu = MPIDR_AFFINITY_LEVEL(mpidr, 0);
 451         cluster = MPIDR_AFFINITY_LEVEL(mpidr, 1);
 452         pr_debug("%s: cluster %u cpu %u\n", __func__, cluster, cpu);
 453
 454         spin_lock(&boot_lock);
 455         sunxi_mc_smp_cpu_table[cluster][cpu]--;
 456         if (sunxi_mc_smp_cpu_table[cluster][cpu] == 1) {
 457                 /* A power_up request went ahead of us. */
 458                 pr_debug("%s: aborting due to a power up request\n",
 459                          __func__);
 460                 spin_unlock(&boot_lock);
 461                 return;
 462         } else if (sunxi_mc_smp_cpu_table[cluster][cpu] > 1) {
 463                 pr_err("Cluster %d CPU%d boots multiple times\n",
 464                        cluster, cpu);
 465                 BUG();
 466         }
 467
 468         last_man = sunxi_mc_smp_cluster_is_down(cluster);
 469         spin_unlock(&boot_lock);
 470
 471         gic_cpu_if_down(0);
 472         if (last_man)
 473                 sunxi_cluster_cache_disable();
 474         else
 475                 v7_exit_coherency_flush(louis);
 476
 477         for (;;)
 478                 wfi();
 479 }
 480
 481 static int sunxi_cpu_powerdown(unsigned int cpu, unsigned int cluster)
 482 {
 483         u32 reg;
 484
 485         pr_debug("%s: cluster %u cpu %u\n", __func__, cluster, cpu);
 486         if (cpu >= SUNXI_CPUS_PER_CLUSTER || cluster >= SUNXI_NR_CLUSTERS)
 487                 return -EINVAL;
 488
 489         /* gate processor power */
 490         reg = readl(prcm_base + PRCM_PWROFF_GATING_REG(cluster));
 491         reg |= PRCM_PWROFF_GATING_REG_CORE(cpu);
 492         writel(reg, prcm_base + PRCM_PWROFF_GATING_REG(cluster));
 493         udelay(20);
 494
 495         /* close power switch */
 496         sunxi_cpu_power_switch_set(cpu, cluster, false);
 497
 498         return 0;
 499 }
 500
 501 static int sunxi_cluster_powerdown(unsigned int cluster)
 502 {
 503         u32 reg;
 504
 505         pr_debug("%s: cluster %u\n", __func__, cluster);
 506         if (cluster >= SUNXI_NR_CLUSTERS)
 507                 return -EINVAL;
 508
 509         /* assert cluster resets or system will hang */
 510         pr_debug("%s: assert cluster reset\n", __func__);
 511         reg = readl(cpucfg_base + CPUCFG_CX_RST_CTRL(cluster));
 512         reg &= ~CPUCFG_CX_RST_CTRL_DBG_SOC_RST;
 513         reg &= ~CPUCFG_CX_RST_CTRL_H_RST;
 514         reg &= ~CPUCFG_CX_RST_CTRL_L2_RST;
 515         writel(reg, cpucfg_base + CPUCFG_CX_RST_CTRL(cluster));
 516
 517         /* gate cluster power */
 518         pr_debug("%s: gate cluster power\n", __func__);
 519         reg = readl(prcm_base + PRCM_PWROFF_GATING_REG(cluster));
 520         if (is_a83t)
 521                 reg |= PRCM_PWROFF_GATING_REG_CLUSTER_SUN8I;
 522         else
 523                 reg |= PRCM_PWROFF_GATING_REG_CLUSTER_SUN9I;
 524         writel(reg, prcm_base + PRCM_PWROFF_GATING_REG(cluster));
 525         udelay(20);
 526
 527         return 0;
 528 }
 529
 530 static int sunxi_mc_smp_cpu_kill(unsigned int l_cpu)
 531 {
 532         unsigned int mpidr, cpu, cluster;
 533         unsigned int tries, count;
 534         int ret = 0;
 535         u32 reg;
 536
 537         mpidr = cpu_logical_map(l_cpu);
 538         cpu = MPIDR_AFFINITY_LEVEL(mpidr, 0);
 539         cluster = MPIDR_AFFINITY_LEVEL(mpidr, 1);
 540
 541         /* This should never happen */
 542         if (WARN_ON(cluster >= SUNXI_NR_CLUSTERS ||
 543                     cpu >= SUNXI_CPUS_PER_CLUSTER))
 544                 return 0;
 545
 546         /* wait for CPU core to die and enter WFI */
 547         count = TIMEOUT_USEC / POLL_USEC;
 548         spin_lock_irq(&boot_lock);
 549         for (tries = 0; tries < count; tries++) {
 550                 spin_unlock_irq(&boot_lock);
 551                 usleep_range(POLL_USEC / 2, POLL_USEC);
 552                 spin_lock_irq(&boot_lock);
 553
 554                 /*
 555                  * If the user turns off a bunch of cores at the same
 556                  * time, the kernel might call cpu_kill before some of
 557                  * them are ready. This is because boot_lock serializes
 558                  * both cpu_die and cpu_kill callbacks. Either one could
 559                  * run first. We should wait for cpu_die to complete.
 560                  */
 561                 if (sunxi_mc_smp_cpu_table[cluster][cpu])
 562                         continue;
 563
 564                 reg = readl(cpucfg_base + CPUCFG_CX_STATUS(cluster));
 565                 if (reg & CPUCFG_CX_STATUS_STANDBYWFI(cpu))
 566                         break;
 567         }
 568
 569         if (tries >= count) {
 570                 ret = ETIMEDOUT;
 571                 goto out;
 572         }
 573
 574         /* power down CPU core */
 575         sunxi_cpu_powerdown(cpu, cluster);
 576
 577         if (!sunxi_mc_smp_cluster_is_down(cluster))
 578                 goto out;
 579
 580         /* wait for cluster L2 WFI */
 581         ret = readl_poll_timeout(cpucfg_base + CPUCFG_CX_STATUS(cluster), reg,
 582                                  reg & CPUCFG_CX_STATUS_STANDBYWFIL2,
 583                                  POLL_USEC, TIMEOUT_USEC);
 584         if (ret) {
 585                 /*
 586                  * Ignore timeout on the cluster. Leaving the cluster on
 587                  * will not affect system execution, just use a bit more
 588                  * power. But returning an error here will only confuse
 589                  * the user as the CPU has already been shutdown.
 590                  */
 591                 ret = 0;
 592                 goto out;
 593         }
 594
 595         /* Power down cluster */
 596         sunxi_cluster_powerdown(cluster);
 597
 598 out:
 599         spin_unlock_irq(&boot_lock);
 600         pr_debug("%s: cluster %u cpu %u powerdown: %d\n",
 601                  __func__, cluster, cpu, ret);
 602         return !ret;
 603 }
 604
 605 static bool sunxi_mc_smp_cpu_can_disable(unsigned int cpu)
 606 {
 607         /* CPU0 hotplug not handled for sun8i-a83t */
 608         if (is_a83t)
 609                 if (cpu == 0)
 610                         return false;
 611         return true;
 612 }
 613 #endif
 614
 615 static const struct smp_operations sunxi_mc_smp_smp_ops __initconst = {
 616         .smp_secondary_init     = sunxi_mc_smp_secondary_init,
 617         .smp_boot_secondary     = sunxi_mc_smp_boot_secondary,
 618 #ifdef CONFIG_HOTPLUG_CPU
 619         .cpu_die                = sunxi_mc_smp_cpu_die,
 620         .cpu_kill               = sunxi_mc_smp_cpu_kill,
 621         .cpu_can_disable        = sunxi_mc_smp_cpu_can_disable,
 622 #endif
 623 };
 624
 625 static bool __init sunxi_mc_smp_cpu_table_init(void)
 626 {
 627         unsigned int mpidr, cpu, cluster;
 628
 629         mpidr = read_cpuid_mpidr();
 630         cpu = MPIDR_AFFINITY_LEVEL(mpidr, 0);
 631         cluster = MPIDR_AFFINITY_LEVEL(mpidr, 1);
 632
 633         if (cluster >= SUNXI_NR_CLUSTERS || cpu >= SUNXI_CPUS_PER_CLUSTER) {
 634                 pr_err("%s: boot CPU is out of bounds!\n", __func__);
 635                 return false;
 636         }
 637         sunxi_mc_smp_cpu_table[cluster][cpu] = 1;
 638         return true;
 639 }
 640
 641 /*
 642  * Adapted from arch/arm/common/mc_smp_entry.c
 643  *
 644  * We need the trampoline code to enable CCI-400 on the first cluster
 645  */
 646 typedef typeof(cpu_reset) phys_reset_t;
 647
 648 static int __init nocache_trampoline(unsigned long __unused)
 649 {
 650         phys_reset_t phys_reset;
 651
 652         setup_mm_for_reboot();
 653         sunxi_cluster_cache_disable_without_axi();
 654
 655         phys_reset = (phys_reset_t)(unsigned long)__pa_symbol(cpu_reset);
 656         phys_reset(__pa_symbol(sunxi_mc_smp_resume), false);
 657         BUG();
 658 }
 659
 660 static int __init sunxi_mc_smp_loopback(void)
 661 {
 662         int ret;
 663
 664         /*
 665          * We're going to soft-restart the current CPU through the
 666          * low-level MCPM code by leveraging the suspend/resume
 667          * infrastructure. Let's play it safe by using cpu_pm_enter()
 668          * in case the CPU init code path resets the VFP or similar.
 669          */
 670         sunxi_mc_smp_first_comer = true;
 671         local_irq_disable();
 672         local_fiq_disable();
 673         ret = cpu_pm_enter();
 674         if (!ret) {
 675                 ret = cpu_suspend(0, nocache_trampoline);
 676                 cpu_pm_exit();
 677         }
 678         local_fiq_enable();
 679         local_irq_enable();
 680         sunxi_mc_smp_first_comer = false;
 681
 682         return ret;
 683 }
 684
 685 /*
 686  * This holds any device nodes that we requested resources for,
 687  * so that we may easily release resources in the error path.
 688  */
 689 struct sunxi_mc_smp_nodes {
 690         struct device_node *prcm_node;
 691         struct device_node *cpucfg_node;
 692         struct device_node *sram_node;
 693         struct device_node *r_cpucfg_node;
 694 };
 695
 696 /* This structure holds SoC-specific bits tied to an enable-method string. */
 697 struct sunxi_mc_smp_data {
 698         const char *enable_method;
 699         int (*get_smp_nodes)(struct sunxi_mc_smp_nodes *nodes);
 700         bool is_a83t;
 701 };
 702
 703 static void __init sunxi_mc_smp_put_nodes(struct sunxi_mc_smp_nodes *nodes)
 704 {
 705         of_node_put(nodes->prcm_node);
 706         of_node_put(nodes->cpucfg_node);
 707         of_node_put(nodes->sram_node);
 708         of_node_put(nodes->r_cpucfg_node);
 709         memset(nodes, 0, sizeof(*nodes));
 710 }
 711
 712 static int __init sun9i_a80_get_smp_nodes(struct sunxi_mc_smp_nodes *nodes)
 713 {
 714         nodes->prcm_node = of_find_compatible_node(NULL, NULL,
 715                                                    "allwinner,sun9i-a80-prcm");
 716         if (!nodes->prcm_node) {
 717                 pr_err("%s: PRCM not available\n", __func__);
 718                 return -ENODEV;
 719         }
 720
 721         nodes->cpucfg_node = of_find_compatible_node(NULL, NULL,
 722                                                      "allwinner,sun9i-a80-cpucfg");
 723         if (!nodes->cpucfg_node) {
 724                 pr_err("%s: CPUCFG not available\n", __func__);
 725                 return -ENODEV;
 726         }
 727
 728         nodes->sram_node = of_find_compatible_node(NULL, NULL,
 729                                                    "allwinner,sun9i-a80-smp-sram");
 730         if (!nodes->sram_node) {
 731                 pr_err("%s: Secure SRAM not available\n", __func__);
 732                 return -ENODEV;
 733         }
 734
 735         return 0;
 736 }
 737
 738 static int __init sun8i_a83t_get_smp_nodes(struct sunxi_mc_smp_nodes *nodes)
 739 {
 740         nodes->prcm_node = of_find_compatible_node(NULL, NULL,
 741                                                    "allwinner,sun8i-a83t-r-ccu");
 742         if (!nodes->prcm_node) {
 743                 pr_err("%s: PRCM not available\n", __func__);
 744                 return -ENODEV;
 745         }
 746
 747         nodes->cpucfg_node = of_find_compatible_node(NULL, NULL,
 748                                                      "allwinner,sun8i-a83t-cpucfg");
 749         if (!nodes->cpucfg_node) {
 750                 pr_err("%s: CPUCFG not available\n", __func__);
 751                 return -ENODEV;
 752         }
 753
 754         nodes->r_cpucfg_node = of_find_compatible_node(NULL, NULL,
 755                                                        "allwinner,sun8i-a83t-r-cpucfg");
 756         if (!nodes->r_cpucfg_node) {
 757                 pr_err("%s: RCPUCFG not available\n", __func__);
 758                 return -ENODEV;
 759         }
 760
 761         return 0;
 762 }
 763
 764 static const struct sunxi_mc_smp_data sunxi_mc_smp_data[] __initconst = {
 765         {
 766                 .enable_method  = "allwinner,sun9i-a80-smp",
 767                 .get_smp_nodes  = sun9i_a80_get_smp_nodes,
 768         },
 769         {
 770                 .enable_method  = "allwinner,sun8i-a83t-smp",
 771                 .get_smp_nodes  = sun8i_a83t_get_smp_nodes,
 772                 .is_a83t        = true,
 773         },
 774 };
 775
 776 static int __init sunxi_mc_smp_init(void)
 777 {
 778         struct sunxi_mc_smp_nodes nodes = { 0 };
 779         struct device_node *node;
 780         struct resource res;
 781         void __iomem *addr;
 782         int i, ret;
 783
 784         /*
 785          * Don't bother checking the "cpus" node, as an enable-method
 786          * property in that node is undocumented.
 787          */
 788         node = of_cpu_device_node_get(0);
 789         if (!node)
 790                 return -ENODEV;
 791
 792         /*
 793          * We can't actually use the enable-method magic in the kernel.
 794          * Our loopback / trampoline code uses the CPU suspend framework,
 795          * which requires the identity mapping be available. It would not
 796          * yet be available if we used the .init_cpus or .prepare_cpus
 797          * callbacks in smp_operations, which we would use if we were to
 798          * use CPU_METHOD_OF_DECLARE
 799          */
 800         for (i = 0; i < ARRAY_SIZE(sunxi_mc_smp_data); i++) {
 801                 ret = of_property_match_string(node, "enable-method",
 802                                                sunxi_mc_smp_data[i].enable_method);
 803                 if (!ret)
 804                         break;
 805         }
 806
 807         is_a83t = sunxi_mc_smp_data[i].is_a83t;
 808
 809         of_node_put(node);
 810         if (ret)
 811                 return -ENODEV;
 812
 813         if (!sunxi_mc_smp_cpu_table_init())
 814                 return -EINVAL;
 815
 816         if (!cci_probed()) {
 817                 pr_err("%s: CCI-400 not available\n", __func__);
 818                 return -ENODEV;
 819         }
 820
 821         /* Get needed device tree nodes */
 822         ret = sunxi_mc_smp_data[i].get_smp_nodes(&nodes);
 823         if (ret)
 824                 goto err_put_nodes;
 825
 826         /*
 827          * Unfortunately we can not request the I/O region for the PRCM.
 828          * It is shared with the PRCM clock.
 829          */
 830         prcm_base = of_iomap(nodes.prcm_node, 0);
 831         if (!prcm_base) {
 832                 pr_err("%s: failed to map PRCM registers\n", __func__);
 833                 ret = -ENOMEM;
 834                 goto err_put_nodes;
 835         }
 836
 837         cpucfg_base = of_io_request_and_map(nodes.cpucfg_node, 0,
 838                                             "sunxi-mc-smp");
 839         if (IS_ERR(cpucfg_base)) {
 840                 ret = PTR_ERR(cpucfg_base);
 841                 pr_err("%s: failed to map CPUCFG registers: %d\n",
 842                        __func__, ret);
 843                 goto err_unmap_prcm;
 844         }
 845
 846         if (is_a83t) {
 847                 r_cpucfg_base = of_io_request_and_map(nodes.r_cpucfg_node,
 848                                                       0, "sunxi-mc-smp");
 849                 if (IS_ERR(r_cpucfg_base)) {
 850                         ret = PTR_ERR(r_cpucfg_base);
 851                         pr_err("%s: failed to map R-CPUCFG registers\n",
 852                                __func__);
 853                         goto err_unmap_release_cpucfg;
 854                 }
 855         } else {
 856                 sram_b_smp_base = of_io_request_and_map(nodes.sram_node, 0,
 857                                                         "sunxi-mc-smp");
 858                 if (IS_ERR(sram_b_smp_base)) {
 859                         ret = PTR_ERR(sram_b_smp_base);
 860                         pr_err("%s: failed to map secure SRAM\n", __func__);
 861                         goto err_unmap_release_cpucfg;
 862                 }
 863         }
 864
 865         /* Configure CCI-400 for boot cluster */
 866         ret = sunxi_mc_smp_loopback();
 867         if (ret) {
 868                 pr_err("%s: failed to configure boot cluster: %d\n",
 869                        __func__, ret);
 870                 goto err_unmap_release_sram_rcpucfg;
 871         }
 872
 873         /* We don't need the device nodes anymore */
 874         sunxi_mc_smp_put_nodes(&nodes);
 875
 876         /* Set the hardware entry point address */
 877         if (is_a83t)
 878                 addr = r_cpucfg_base + R_CPUCFG_CPU_SOFT_ENTRY_REG;
 879         else
 880                 addr = prcm_base + PRCM_CPU_SOFT_ENTRY_REG;
 881         writel(__pa_symbol(sunxi_mc_smp_secondary_startup), addr);
 882
 883         /* Actually enable multi cluster SMP */
 884         smp_set_ops(&sunxi_mc_smp_smp_ops);
 885
 886         pr_info("sunxi multi cluster SMP support installed\n");
 887
 888         return 0;
 889
 890 err_unmap_release_sram_rcpucfg:
 891         if (is_a83t) {
 892                 iounmap(r_cpucfg_base);
 893                 of_address_to_resource(nodes.r_cpucfg_node, 0, &res);
 894         } else {
 895                 iounmap(sram_b_smp_base);
 896                 of_address_to_resource(nodes.sram_node, 0, &res);
 897         }
 898         release_mem_region(res.start, resource_size(&res));
 899 err_unmap_release_cpucfg:
 900         iounmap(cpucfg_base);
 901         of_address_to_resource(nodes.cpucfg_node, 0, &res);
 902         release_mem_region(res.start, resource_size(&res));
 903 err_unmap_prcm:
 904         iounmap(prcm_base);
 905 err_put_nodes:
 906         sunxi_mc_smp_put_nodes(&nodes);
 907         return ret;
 908 }
 909
 910 early_initcall(sunxi_mc_smp_init);