root/arch/arm/mach-omap2/omap-smp.c

DEFINITIONS

1. omap4_get_scu_base
2. omap5_erratum_workaround_801819
3. omap5_erratum_workaround_801819
4. omap5_secondary_harden_predictor
5. omap5_secondary_harden_predictor
6. omap4_secondary_init
7. omap4_boot_secondary
8. omap4_smp_init_cpus
9. omap4_smp_cpu1_startup_valid
10. omap4_smp_maybe_reset_cpu1
11. omap4_smp_prepare_cpus

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * OMAP4 SMP source file. It contains platform specific functions
   4  * needed for the linux smp kernel.
   5  *
   6  * Copyright (C) 2009 Texas Instruments, Inc.
   7  *
   8  * Author:
   9  *      Santosh Shilimkar <santosh.shilimkar@ti.com>
  10  *
  11  * Platform file needed for the OMAP4 SMP. This file is based on arm
  12  * realview smp platform.
  13  * * Copyright (c) 2002 ARM Limited.
  14  */
  15 #include <linux/init.h>
  16 #include <linux/device.h>
  17 #include <linux/smp.h>
  18 #include <linux/io.h>
  19 #include <linux/irqchip/arm-gic.h>
  20 
  21 #include <asm/sections.h>
  22 #include <asm/smp_scu.h>
  23 #include <asm/virt.h>
  24 
  25 #include "omap-secure.h"
  26 #include "omap-wakeupgen.h"
  27 #include <asm/cputype.h>
  28 
  29 #include "soc.h"
  30 #include "iomap.h"
  31 #include "common.h"
  32 #include "clockdomain.h"
  33 #include "pm.h"
  34 
  35 #define CPU_MASK                0xff0ffff0
  36 #define CPU_CORTEX_A9           0x410FC090
  37 #define CPU_CORTEX_A15          0x410FC0F0
  38 
  39 #define OMAP5_CORE_COUNT        0x2
  40 
  41 #define AUX_CORE_BOOT0_GP_RELEASE       0x020
  42 #define AUX_CORE_BOOT0_HS_RELEASE       0x200
  43 
  44 struct omap_smp_config {
  45         unsigned long cpu1_rstctrl_pa;
  46         void __iomem *cpu1_rstctrl_va;
  47         void __iomem *scu_base;
  48         void __iomem *wakeupgen_base;
  49         void *startup_addr;
  50 };
  51 
  52 static struct omap_smp_config cfg;
  53 
  54 static const struct omap_smp_config omap443x_cfg __initconst = {
  55         .cpu1_rstctrl_pa = 0x4824380c,
  56         .startup_addr = omap4_secondary_startup,
  57 };
  58 
  59 static const struct omap_smp_config omap446x_cfg __initconst = {
  60         .cpu1_rstctrl_pa = 0x4824380c,
  61         .startup_addr = omap4460_secondary_startup,
  62 };
  63 
  64 static const struct omap_smp_config omap5_cfg __initconst = {
  65         .cpu1_rstctrl_pa = 0x48243810,
  66         .startup_addr = omap5_secondary_startup,
  67 };
  68 
  69 void __iomem *omap4_get_scu_base(void)
  70 {
  71         return cfg.scu_base;
  72 }
  73 
  74 #ifdef CONFIG_OMAP5_ERRATA_801819
  75 void omap5_erratum_workaround_801819(void)
  76 {
  77         u32 acr, revidr;
  78         u32 acr_mask;
  79 
  80         /* REVIDR[3] indicates erratum fix available on silicon */
  81         asm volatile ("mrc p15, 0, %0, c0, c0, 6" : "=r" (revidr));
  82         if (revidr & (0x1 << 3))
  83                 return;
  84 
  85         asm volatile ("mrc p15, 0, %0, c1, c0, 1" : "=r" (acr));
  86         /*
  87          * BIT(27) - Disables streaming. All write-allocate lines allocate in
  88          * the L1 or L2 cache.
  89          * BIT(25) - Disables streaming. All write-allocate lines allocate in
  90          * the L1 cache.
  91          */
  92         acr_mask = (0x3 << 25) | (0x3 << 27);
  93         /* do we already have it done.. if yes, skip expensive smc */
  94         if ((acr & acr_mask) == acr_mask)
  95                 return;
  96 
  97         acr |= acr_mask;
  98         omap_smc1(OMAP5_DRA7_MON_SET_ACR_INDEX, acr);
  99 
 100         pr_debug("%s: ARM erratum workaround 801819 applied on CPU%d\n",
 101                  __func__, smp_processor_id());
 102 }
 103 #else
 104 static inline void omap5_erratum_workaround_801819(void) { }
 105 #endif
 106 
 107 #ifdef CONFIG_HARDEN_BRANCH_PREDICTOR
 108 /*
 109  * Configure ACR and enable ACTLR[0] (Enable invalidates of BTB with
 110  * ICIALLU) to activate the workaround for secondary Core.
 111  * NOTE: it is assumed that the primary core's configuration is done
 112  * by the boot loader (kernel will detect a misconfiguration and complain
 113  * if this is not done).
 114  *
 115  * In General Purpose(GP) devices, ACR bit settings can only be done
 116  * by ROM code in "secure world" using the smc call and there is no
 117  * option to update the "firmware" on such devices. This also works for
 118  * High security(HS) devices, as a backup option in case the
 119  * "update" is not done in the "security firmware".
 120  */
 121 static void omap5_secondary_harden_predictor(void)
 122 {
 123         u32 acr, acr_mask;
 124 
 125         asm volatile ("mrc p15, 0, %0, c1, c0, 1" : "=r" (acr));
 126 
 127         /*
 128          * ACTLR[0] (Enable invalidates of BTB with ICIALLU)
 129          */
 130         acr_mask = BIT(0);
 131 
 132         /* Do we already have it done.. if yes, skip expensive smc */
 133         if ((acr & acr_mask) == acr_mask)
 134                 return;
 135 
 136         acr |= acr_mask;
 137         omap_smc1(OMAP5_DRA7_MON_SET_ACR_INDEX, acr);
 138 
 139         pr_debug("%s: ARM ACR setup for CVE_2017_5715 applied on CPU%d\n",
 140                  __func__, smp_processor_id());
 141 }
 142 #else
 143 static inline void omap5_secondary_harden_predictor(void) { }
 144 #endif
 145 
 146 static void omap4_secondary_init(unsigned int cpu)
 147 {
 148         /*
 149          * Configure ACTRL and enable NS SMP bit access on CPU1 on HS device.
 150          * OMAP44XX EMU/HS devices - CPU0 SMP bit access is enabled in PPA
 151          * init and for CPU1, a secure PPA API provided. CPU0 must be ON
 152          * while executing NS_SMP API on CPU1 and PPA version must be 1.4.0+.
 153          * OMAP443X GP devices- SMP bit isn't accessible.
 154          * OMAP446X GP devices - SMP bit access is enabled on both CPUs.
 155          */
 156         if (soc_is_omap443x() && (omap_type() != OMAP2_DEVICE_TYPE_GP))
 157                 omap_secure_dispatcher(OMAP4_PPA_CPU_ACTRL_SMP_INDEX,
 158                                                         4, 0, 0, 0, 0, 0);
 159 
 160         if (soc_is_omap54xx() || soc_is_dra7xx()) {
 161                 /*
 162                  * Configure the CNTFRQ register for the secondary cpu's which
 163                  * indicates the frequency of the cpu local timers.
 164                  */
 165                 set_cntfreq();
 166                 /* Configure ACR to disable streaming WA for 801819 */
 167                 omap5_erratum_workaround_801819();
 168                 /* Enable ACR to allow for ICUALLU workaround */
 169                 omap5_secondary_harden_predictor();
 170         }
 171 }
 172 
 173 static int omap4_boot_secondary(unsigned int cpu, struct task_struct *idle)
 174 {
 175         static struct clockdomain *cpu1_clkdm;
 176         static bool booted;
 177         static struct powerdomain *cpu1_pwrdm;
 178 
 179         /*
 180          * Update the AuxCoreBoot0 with boot state for secondary core.
 181          * omap4_secondary_startup() routine will hold the secondary core till
 182          * the AuxCoreBoot1 register is updated with cpu state
 183          * A barrier is added to ensure that write buffer is drained
 184          */
 185         if (omap_secure_apis_support())
 186                 omap_modify_auxcoreboot0(AUX_CORE_BOOT0_HS_RELEASE,
 187                                          0xfffffdff);
 188         else
 189                 writel_relaxed(AUX_CORE_BOOT0_GP_RELEASE,
 190                                cfg.wakeupgen_base + OMAP_AUX_CORE_BOOT_0);
 191 
 192         if (!cpu1_clkdm && !cpu1_pwrdm) {
 193                 cpu1_clkdm = clkdm_lookup("mpu1_clkdm");
 194                 cpu1_pwrdm = pwrdm_lookup("cpu1_pwrdm");
 195         }
 196 
 197         /*
 198          * The SGI(Software Generated Interrupts) are not wakeup capable
 199          * from low power states. This is known limitation on OMAP4 and
 200          * needs to be worked around by using software forced clockdomain
 201          * wake-up. To wakeup CPU1, CPU0 forces the CPU1 clockdomain to
 202          * software force wakeup. The clockdomain is then put back to
 203          * hardware supervised mode.
 204          * More details can be found in OMAP4430 TRM - Version J
 205          * Section :
 206          *      4.3.4.2 Power States of CPU0 and CPU1
 207          */
 208         if (booted && cpu1_pwrdm && cpu1_clkdm) {
 209                 /*
 210                  * GIC distributor control register has changed between
 211                  * CortexA9 r1pX and r2pX. The Control Register secure
 212                  * banked version is now composed of 2 bits:
 213                  * bit 0 == Secure Enable
 214                  * bit 1 == Non-Secure Enable
 215                  * The Non-Secure banked register has not changed
 216                  * Because the ROM Code is based on the r1pX GIC, the CPU1
 217                  * GIC restoration will cause a problem to CPU0 Non-Secure SW.
 218                  * The workaround must be:
 219                  * 1) Before doing the CPU1 wakeup, CPU0 must disable
 220                  * the GIC distributor
 221                  * 2) CPU1 must re-enable the GIC distributor on
 222                  * it's wakeup path.
 223                  */
 224                 if (IS_PM44XX_ERRATUM(PM_OMAP4_ROM_SMP_BOOT_ERRATUM_GICD)) {
 225                         local_irq_disable();
 226                         gic_dist_disable();
 227                 }
 228 
 229                 /*
 230                  * Ensure that CPU power state is set to ON to avoid CPU
 231                  * powerdomain transition on wfi
 232                  */
 233                 clkdm_deny_idle_nolock(cpu1_clkdm);
 234                 pwrdm_set_next_pwrst(cpu1_pwrdm, PWRDM_POWER_ON);
 235                 clkdm_allow_idle_nolock(cpu1_clkdm);
 236 
 237                 if (IS_PM44XX_ERRATUM(PM_OMAP4_ROM_SMP_BOOT_ERRATUM_GICD)) {
 238                         while (gic_dist_disabled()) {
 239                                 udelay(1);
 240                                 cpu_relax();
 241                         }
 242                         gic_timer_retrigger();
 243                         local_irq_enable();
 244                 }
 245         } else {
 246                 dsb_sev();
 247                 booted = true;
 248         }
 249 
 250         arch_send_wakeup_ipi_mask(cpumask_of(cpu));
 251 
 252         return 0;
 253 }
 254 
 255 /*
 256  * Initialise the CPU possible map early - this describes the CPUs
 257  * which may be present or become present in the system.
 258  */
 259 static void __init omap4_smp_init_cpus(void)
 260 {
 261         unsigned int i = 0, ncores = 1, cpu_id;
 262 
 263         /* Use ARM cpuid check here, as SoC detection will not work so early */
 264         cpu_id = read_cpuid_id() & CPU_MASK;
 265         if (cpu_id == CPU_CORTEX_A9) {
 266                 /*
 267                  * Currently we can't call ioremap here because
 268                  * SoC detection won't work until after init_early.
 269                  */
 270                 cfg.scu_base =  OMAP2_L4_IO_ADDRESS(scu_a9_get_base());
 271                 BUG_ON(!cfg.scu_base);
 272                 ncores = scu_get_core_count(cfg.scu_base);
 273         } else if (cpu_id == CPU_CORTEX_A15) {
 274                 ncores = OMAP5_CORE_COUNT;
 275         }
 276 
 277         /* sanity check */
 278         if (ncores > nr_cpu_ids) {
 279                 pr_warn("SMP: %u cores greater than maximum (%u), clipping\n",
 280                         ncores, nr_cpu_ids);
 281                 ncores = nr_cpu_ids;
 282         }
 283 
 284         for (i = 0; i < ncores; i++)
 285                 set_cpu_possible(i, true);
 286 }
 287 
 288 /*
 289  * For now, just make sure the start-up address is not within the booting
 290  * kernel space as that means we just overwrote whatever secondary_startup()
 291  * code there was.
 292  */
 293 static bool __init omap4_smp_cpu1_startup_valid(unsigned long addr)
 294 {
 295         if ((addr >= __pa(PAGE_OFFSET)) && (addr <= __pa(__bss_start)))
 296                 return false;
 297 
 298         return true;
 299 }
 300 
 301 /*
 302  * We may need to reset CPU1 before configuring, otherwise kexec boot can end
 303  * up trying to use old kernel startup address or suspend-resume will
 304  * occasionally fail to bring up CPU1 on 4430 if CPU1 fails to enter deeper
 305  * idle states.
 306  */
 307 static void __init omap4_smp_maybe_reset_cpu1(struct omap_smp_config *c)
 308 {
 309         unsigned long cpu1_startup_pa, cpu1_ns_pa_addr;
 310         bool needs_reset = false;
 311         u32 released;
 312 
 313         if (omap_secure_apis_support())
 314                 released = omap_read_auxcoreboot0() & AUX_CORE_BOOT0_HS_RELEASE;
 315         else
 316                 released = readl_relaxed(cfg.wakeupgen_base +
 317                                          OMAP_AUX_CORE_BOOT_0) &
 318                                                 AUX_CORE_BOOT0_GP_RELEASE;
 319         if (released) {
 320                 pr_warn("smp: CPU1 not parked?\n");
 321 
 322                 return;
 323         }
 324 
 325         cpu1_startup_pa = readl_relaxed(cfg.wakeupgen_base +
 326                                         OMAP_AUX_CORE_BOOT_1);
 327 
 328         /* Did the configured secondary_startup() get overwritten? */
 329         if (!omap4_smp_cpu1_startup_valid(cpu1_startup_pa))
 330                 needs_reset = true;
 331 
 332         /*
 333          * If omap4 or 5 has NS_PA_ADDR configured, CPU1 may be in a
 334          * deeper idle state in WFI and will wake to an invalid address.
 335          */
 336         if ((soc_is_omap44xx() || soc_is_omap54xx())) {
 337                 cpu1_ns_pa_addr = omap4_get_cpu1_ns_pa_addr();
 338                 if (!omap4_smp_cpu1_startup_valid(cpu1_ns_pa_addr))
 339                         needs_reset = true;
 340         } else {
 341                 cpu1_ns_pa_addr = 0;
 342         }
 343 
 344         if (!needs_reset || !c->cpu1_rstctrl_va)
 345                 return;
 346 
 347         pr_info("smp: CPU1 parked within kernel, needs reset (0x%lx 0x%lx)\n",
 348                 cpu1_startup_pa, cpu1_ns_pa_addr);
 349 
 350         writel_relaxed(1, c->cpu1_rstctrl_va);
 351         readl_relaxed(c->cpu1_rstctrl_va);
 352         writel_relaxed(0, c->cpu1_rstctrl_va);
 353 }
 354 
 355 static void __init omap4_smp_prepare_cpus(unsigned int max_cpus)
 356 {
 357         const struct omap_smp_config *c = NULL;
 358 
 359         if (soc_is_omap443x())
 360                 c = &omap443x_cfg;
 361         else if (soc_is_omap446x())
 362                 c = &omap446x_cfg;
 363         else if (soc_is_dra74x() || soc_is_omap54xx() || soc_is_dra76x())
 364                 c = &omap5_cfg;
 365 
 366         if (!c) {
 367                 pr_err("%s Unknown SMP SoC?\n", __func__);
 368                 return;
 369         }
 370 
 371         /* Must preserve cfg.scu_base set earlier */
 372         cfg.cpu1_rstctrl_pa = c->cpu1_rstctrl_pa;
 373         cfg.startup_addr = c->startup_addr;
 374         cfg.wakeupgen_base = omap_get_wakeupgen_base();
 375 
 376         if (soc_is_dra74x() || soc_is_omap54xx() || soc_is_dra76x()) {
 377                 if ((__boot_cpu_mode & MODE_MASK) == HYP_MODE)
 378                         cfg.startup_addr = omap5_secondary_hyp_startup;
 379                 omap5_erratum_workaround_801819();
 380         }
 381 
 382         cfg.cpu1_rstctrl_va = ioremap(cfg.cpu1_rstctrl_pa, 4);
 383         if (!cfg.cpu1_rstctrl_va)
 384                 return;
 385 
 386         /*
 387          * Initialise the SCU and wake up the secondary core using
 388          * wakeup_secondary().
 389          */
 390         if (cfg.scu_base)
 391                 scu_enable(cfg.scu_base);
 392 
 393         omap4_smp_maybe_reset_cpu1(&cfg);
 394 
 395         /*
 396          * Write the address of secondary startup routine into the
 397          * AuxCoreBoot1 where ROM code will jump and start executing
 398          * on secondary core once out of WFE
 399          * A barrier is added to ensure that write buffer is drained
 400          */
 401         if (omap_secure_apis_support())
 402                 omap_auxcoreboot_addr(__pa_symbol(cfg.startup_addr));
 403         else
 404                 writel_relaxed(__pa_symbol(cfg.startup_addr),
 405                                cfg.wakeupgen_base + OMAP_AUX_CORE_BOOT_1);
 406 }
 407 
 408 const struct smp_operations omap4_smp_ops __initconst = {
 409         .smp_init_cpus          = omap4_smp_init_cpus,
 410         .smp_prepare_cpus       = omap4_smp_prepare_cpus,
 411         .smp_secondary_init     = omap4_secondary_init,
 412         .smp_boot_secondary     = omap4_boot_secondary,
 413 #ifdef CONFIG_HOTPLUG_CPU
 414         .cpu_die                = omap4_cpu_die,
 415         .cpu_kill               = omap4_cpu_kill,
 416 #endif
 417 };