/* * This file is subject to the terms and conditions of the GNU General Public * License. See the file "COPYING" in the main directory of this archive * for more details. * * Copyright (C) 2011 by Kevin Cernekee (cernekee@gmail.com) * * SMP support for BMIPS */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include static int __maybe_unused max_cpus = 1; /* these may be configured by the platform code */ int bmips_smp_enabled = 1; int bmips_cpu_offset; cpumask_t bmips_booted_mask; unsigned long bmips_tp1_irqs = IE_IRQ1; #define RESET_FROM_KSEG0 0x80080800 #define RESET_FROM_KSEG1 0xa0080800 static void bmips_set_reset_vec(int cpu, u32 val); #ifdef CONFIG_SMP /* initial $sp, $gp - used by arch/mips/kernel/bmips_vec.S */ unsigned long bmips_smp_boot_sp; unsigned long bmips_smp_boot_gp; static void bmips43xx_send_ipi_single(int cpu, unsigned int action); static void bmips5000_send_ipi_single(int cpu, unsigned int action); static irqreturn_t bmips43xx_ipi_interrupt(int irq, void *dev_id); static irqreturn_t bmips5000_ipi_interrupt(int irq, void *dev_id); /* SW interrupts 0,1 are used for interprocessor signaling */ #define IPI0_IRQ (MIPS_CPU_IRQ_BASE + 0) #define IPI1_IRQ (MIPS_CPU_IRQ_BASE + 1) #define CPUNUM(cpu, shift) (((cpu) + bmips_cpu_offset) << (shift)) #define ACTION_CLR_IPI(cpu, ipi) (0x2000 | CPUNUM(cpu, 9) | ((ipi) << 8)) #define ACTION_SET_IPI(cpu, ipi) (0x3000 | CPUNUM(cpu, 9) | ((ipi) << 8)) #define ACTION_BOOT_THREAD(cpu) (0x08 | CPUNUM(cpu, 0)) static void __init bmips_smp_setup(void) { int i, cpu = 1, boot_cpu = 0; int cpu_hw_intr; switch (current_cpu_type()) { case CPU_BMIPS4350: case CPU_BMIPS4380: /* arbitration priority */ clear_c0_brcm_cmt_ctrl(0x30); /* NBK and weak order flags */ set_c0_brcm_config_0(0x30000); /* Find out if we are running on TP0 or TP1 */ boot_cpu = !!(read_c0_brcm_cmt_local() & (1 << 31)); /* * MIPS interrupts 0,1 (SW INT 0,1) cross over to the other * thread * MIPS interrupt 2 (HW INT 0) is the CPU0 L1 controller output * MIPS interrupt 3 (HW INT 1) is the CPU1 L1 controller output */ if (boot_cpu == 0) cpu_hw_intr = 0x02; else cpu_hw_intr = 0x1d; change_c0_brcm_cmt_intr(0xf8018000, (cpu_hw_intr << 27) | (0x03 << 15)); /* single core, 2 threads (2 pipelines) */ max_cpus = 2; break; case CPU_BMIPS5000: /* enable raceless SW interrupts */ set_c0_brcm_config(0x03 << 22); /* route HW interrupt 0 to CPU0, HW interrupt 1 to CPU1 */ change_c0_brcm_mode(0x1f << 27, 0x02 << 27); /* N cores, 2 threads per core */ max_cpus = (((read_c0_brcm_config() >> 6) & 0x03) + 1) << 1; /* clear any pending SW interrupts */ for (i = 0; i < max_cpus; i++) { write_c0_brcm_action(ACTION_CLR_IPI(i, 0)); write_c0_brcm_action(ACTION_CLR_IPI(i, 1)); } break; default: max_cpus = 1; } if (!bmips_smp_enabled) max_cpus = 1; /* this can be overridden by the BSP */ if (!board_ebase_setup) board_ebase_setup = &bmips_ebase_setup; __cpu_number_map[boot_cpu] = 0; __cpu_logical_map[0] = boot_cpu; for (i = 0; i < max_cpus; i++) { if (i != boot_cpu) { __cpu_number_map[i] = cpu; __cpu_logical_map[cpu] = i; cpu++; } set_cpu_possible(i, 1); set_cpu_present(i, 1); } } /* * IPI IRQ setup - runs on CPU0 */ static void bmips_prepare_cpus(unsigned int max_cpus) { irqreturn_t (*bmips_ipi_interrupt)(int irq, void *dev_id); switch (current_cpu_type()) { case CPU_BMIPS4350: case CPU_BMIPS4380: bmips_ipi_interrupt = bmips43xx_ipi_interrupt; break; case CPU_BMIPS5000: bmips_ipi_interrupt = bmips5000_ipi_interrupt; break; default: return; } if (request_irq(IPI0_IRQ, bmips_ipi_interrupt, IRQF_PERCPU | IRQF_NO_SUSPEND, "smp_ipi0", NULL)) panic("Can't request IPI0 interrupt"); if (request_irq(IPI1_IRQ, bmips_ipi_interrupt, IRQF_PERCPU | IRQF_NO_SUSPEND, "smp_ipi1", NULL)) panic("Can't request IPI1 interrupt"); } /* * Tell the hardware to boot CPUx - runs on CPU0 */ static int bmips_boot_secondary(int cpu, struct task_struct *idle) { bmips_smp_boot_sp = __KSTK_TOS(idle); bmips_smp_boot_gp = (unsigned long)task_thread_info(idle); mb(); /* * Initial boot sequence for secondary CPU: * bmips_reset_nmi_vec @ a000_0000 -> * bmips_smp_entry -> * plat_wired_tlb_setup (cached function call; optional) -> * start_secondary (cached jump) * * Warm restart sequence: * play_dead WAIT loop -> * bmips_smp_int_vec @ BMIPS_WARM_RESTART_VEC -> * eret to play_dead -> * bmips_secondary_reentry -> * start_secondary */ pr_info("SMP: Booting CPU%d...\n", cpu); if (cpumask_test_cpu(cpu, &bmips_booted_mask)) { /* kseg1 might not exist if this CPU enabled XKS01 */ bmips_set_reset_vec(cpu, RESET_FROM_KSEG0); switch (current_cpu_type()) { case CPU_BMIPS4350: case CPU_BMIPS4380: bmips43xx_send_ipi_single(cpu, 0); break; case CPU_BMIPS5000: bmips5000_send_ipi_single(cpu, 0); break; } } else { bmips_set_reset_vec(cpu, RESET_FROM_KSEG1); switch (current_cpu_type()) { case CPU_BMIPS4350: case CPU_BMIPS4380: /* Reset slave TP1 if booting from TP0 */ if (cpu_logical_map(cpu) == 1) set_c0_brcm_cmt_ctrl(0x01); break; case CPU_BMIPS5000: write_c0_brcm_action(ACTION_BOOT_THREAD(cpu)); break; } cpumask_set_cpu(cpu, &bmips_booted_mask); } return 0; } /* * Early setup - runs on secondary CPU after cache probe */ static void bmips_init_secondary(void) { switch (current_cpu_type()) { case CPU_BMIPS4350: case CPU_BMIPS4380: clear_c0_cause(smp_processor_id() ? C_SW1 : C_SW0); break; case CPU_BMIPS5000: write_c0_brcm_action(ACTION_CLR_IPI(smp_processor_id(), 0)); cpu_set_core(¤t_cpu_data, (read_c0_brcm_config() >> 25) & 3); break; } } /* * Late setup - runs on secondary CPU before entering the idle loop */ static void bmips_smp_finish(void) { pr_info("SMP: CPU%d is running\n", smp_processor_id()); /* make sure there won't be a timer interrupt for a little while */ write_c0_compare(read_c0_count() + mips_hpt_frequency / HZ); irq_enable_hazard(); set_c0_status(IE_SW0 | IE_SW1 | bmips_tp1_irqs | IE_IRQ5 | ST0_IE); irq_enable_hazard(); } /* * BMIPS5000 raceless IPIs * * Each CPU has two inbound SW IRQs which are independent of all other CPUs. * IPI0 is used for SMP_RESCHEDULE_YOURSELF * IPI1 is used for SMP_CALL_FUNCTION */ static void bmips5000_send_ipi_single(int cpu, unsigned int action) { write_c0_brcm_action(ACTION_SET_IPI(cpu, action == SMP_CALL_FUNCTION)); } static irqreturn_t bmips5000_ipi_interrupt(int irq, void *dev_id) { int action = irq - IPI0_IRQ; write_c0_brcm_action(ACTION_CLR_IPI(smp_processor_id(), action)); if (action == 0) scheduler_ipi(); else generic_smp_call_function_interrupt(); return IRQ_HANDLED; } static void bmips5000_send_ipi_mask(const struct cpumask *mask, unsigned int action) { unsigned int i; for_each_cpu(i, mask) bmips5000_send_ipi_single(i, action); } /* * BMIPS43xx racey IPIs * * We use one inbound SW IRQ for each CPU. * * A spinlock must be held in order to keep CPUx from accidentally clearing * an incoming IPI when it writes CP0 CAUSE to raise an IPI on CPUy. The * same spinlock is used to protect the action masks. */ static DEFINE_SPINLOCK(ipi_lock); static DEFINE_PER_CPU(int, ipi_action_mask); static void bmips43xx_send_ipi_single(int cpu, unsigned int action) { unsigned long flags; spin_lock_irqsave(&ipi_lock, flags); set_c0_cause(cpu ? C_SW1 : C_SW0); per_cpu(ipi_action_mask, cpu) |= action; irq_enable_hazard(); spin_unlock_irqrestore(&ipi_lock, flags); } static irqreturn_t bmips43xx_ipi_interrupt(int irq, void *dev_id) { unsigned long flags; int action, cpu = irq - IPI0_IRQ; spin_lock_irqsave(&ipi_lock, flags); action = __this_cpu_read(ipi_action_mask); per_cpu(ipi_action_mask, cpu) = 0; clear_c0_cause(cpu ? C_SW1 : C_SW0); spin_unlock_irqrestore(&ipi_lock, flags); if (action & SMP_RESCHEDULE_YOURSELF) scheduler_ipi(); if (action & SMP_CALL_FUNCTION) generic_smp_call_function_interrupt(); return IRQ_HANDLED; } static void bmips43xx_send_ipi_mask(const struct cpumask *mask, unsigned int action) { unsigned int i; for_each_cpu(i, mask) bmips43xx_send_ipi_single(i, action); } #ifdef CONFIG_HOTPLUG_CPU static int bmips_cpu_disable(void) { unsigned int cpu = smp_processor_id(); if (cpu == 0) return -EBUSY; pr_info("SMP: CPU%d is offline\n", cpu); set_cpu_online(cpu, false); calculate_cpu_foreign_map(); irq_cpu_offline(); clear_c0_status(IE_IRQ5); local_flush_tlb_all(); local_flush_icache_range(0, ~0); return 0; } static void bmips_cpu_die(unsigned int cpu) { } void __ref play_dead(void) { idle_task_exit(); /* flush data cache */ _dma_cache_wback_inv(0, ~0); /* * Wakeup is on SW0 or SW1; disable everything else * Use BEV !IV (BMIPS_WARM_RESTART_VEC) to avoid the regular Linux * IRQ handlers; this clears ST0_IE and returns immediately. */ clear_c0_cause(CAUSEF_IV | C_SW0 | C_SW1); change_c0_status( IE_IRQ5 | bmips_tp1_irqs | IE_SW0 | IE_SW1 | ST0_IE | ST0_BEV, IE_SW0 | IE_SW1 | ST0_IE | ST0_BEV); irq_disable_hazard(); /* * wait for SW interrupt from bmips_boot_secondary(), then jump * back to start_secondary() */ __asm__ __volatile__( " wait\n" " j bmips_secondary_reentry\n" : : : "memory"); } #endif /* CONFIG_HOTPLUG_CPU */ const struct plat_smp_ops bmips43xx_smp_ops = { .smp_setup = bmips_smp_setup, .prepare_cpus = bmips_prepare_cpus, .boot_secondary = bmips_boot_secondary, .smp_finish = bmips_smp_finish, .init_secondary = bmips_init_secondary, .send_ipi_single = bmips43xx_send_ipi_single, .send_ipi_mask = bmips43xx_send_ipi_mask, #ifdef CONFIG_HOTPLUG_CPU .cpu_disable = bmips_cpu_disable, .cpu_die = bmips_cpu_die, #endif }; const struct plat_smp_ops bmips5000_smp_ops = { .smp_setup = bmips_smp_setup, .prepare_cpus = bmips_prepare_cpus, .boot_secondary = bmips_boot_secondary, .smp_finish = bmips_smp_finish, .init_secondary = bmips_init_secondary, .send_ipi_single = bmips5000_send_ipi_single, .send_ipi_mask = bmips5000_send_ipi_mask, #ifdef CONFIG_HOTPLUG_CPU .cpu_disable = bmips_cpu_disable, .cpu_die = bmips_cpu_die, #endif }; #endif /* CONFIG_SMP */ /*********************************************************************** * BMIPS vector relocation * This is primarily used for SMP boot, but it is applicable to some * UP BMIPS systems as well. ***********************************************************************/ static void bmips_wr_vec(unsigned long dst, char *start, char *end) { memcpy((void *)dst, start, end - start); dma_cache_wback(dst, end - start); local_flush_icache_range(dst, dst + (end - start)); instruction_hazard(); } static inline void bmips_nmi_handler_setup(void) { bmips_wr_vec(BMIPS_NMI_RESET_VEC, &bmips_reset_nmi_vec, &bmips_reset_nmi_vec_end); bmips_wr_vec(BMIPS_WARM_RESTART_VEC, &bmips_smp_int_vec, &bmips_smp_int_vec_end); } struct reset_vec_info { int cpu; u32 val; }; static void bmips_set_reset_vec_remote(void *vinfo) { struct reset_vec_info *info = vinfo; int shift = info->cpu & 0x01 ? 16 : 0; u32 mask = ~(0xffff << shift), val = info->val >> 16; preempt_disable(); if (smp_processor_id() > 0) { smp_call_function_single(0, &bmips_set_reset_vec_remote, info, 1); } else { if (info->cpu & 0x02) { /* BMIPS5200 "should" use mask/shift, but it's buggy */ bmips_write_zscm_reg(0xa0, (val << 16) | val); bmips_read_zscm_reg(0xa0); } else { write_c0_brcm_bootvec((read_c0_brcm_bootvec() & mask) | (val << shift)); } } preempt_enable(); } static void bmips_set_reset_vec(int cpu, u32 val) { struct reset_vec_info info; if (current_cpu_type() == CPU_BMIPS5000) { /* this needs to run from CPU0 (which is always online) */ info.cpu = cpu; info.val = val; bmips_set_reset_vec_remote(&info); } else { void __iomem *cbr = BMIPS_GET_CBR(); if (cpu == 0) __raw_writel(val, cbr + BMIPS_RELO_VECTOR_CONTROL_0); else { if (current_cpu_type() != CPU_BMIPS4380) return; __raw_writel(val, cbr + BMIPS_RELO_VECTOR_CONTROL_1); } } __sync(); back_to_back_c0_hazard(); } void bmips_ebase_setup(void) { unsigned long new_ebase = ebase; BUG_ON(ebase != CKSEG0); switch (current_cpu_type()) { case CPU_BMIPS4350: /* * BMIPS4350 cannot relocate the normal vectors, but it * can relocate the BEV=1 vectors. So CPU1 starts up at * the relocated BEV=1, IV=0 general exception vector @ * 0xa000_0380. * * set_uncached_handler() is used here because: * - CPU1 will run this from uncached space * - None of the cacheflush functions are set up yet */ set_uncached_handler(BMIPS_WARM_RESTART_VEC - CKSEG0, &bmips_smp_int_vec, 0x80); __sync(); return; case CPU_BMIPS3300: case CPU_BMIPS4380: /* * 0x8000_0000: reset/NMI (initially in kseg1) * 0x8000_0400: normal vectors */ new_ebase = 0x80000400; bmips_set_reset_vec(0, RESET_FROM_KSEG0); break; case CPU_BMIPS5000: /* * 0x8000_0000: reset/NMI (initially in kseg1) * 0x8000_1000: normal vectors */ new_ebase = 0x80001000; bmips_set_reset_vec(0, RESET_FROM_KSEG0); write_c0_ebase(new_ebase); break; default: return; } board_nmi_handler_setup = &bmips_nmi_handler_setup; ebase = new_ebase; } asmlinkage void __weak plat_wired_tlb_setup(void) { /* * Called when starting/restarting a secondary CPU. * Kernel stacks and other important data might only be accessible * once the wired entries are present. */ } void __init bmips_cpu_setup(void) { void __iomem __maybe_unused *cbr = BMIPS_GET_CBR(); u32 __maybe_unused cfg; switch (current_cpu_type()) { case CPU_BMIPS3300: /* Set BIU to async mode */ set_c0_brcm_bus_pll(BIT(22)); __sync(); /* put the BIU back in sync mode */ clear_c0_brcm_bus_pll(BIT(22)); /* clear BHTD to enable branch history table */ clear_c0_brcm_reset(BIT(16)); /* Flush and enable RAC */ cfg = __raw_readl(cbr + BMIPS_RAC_CONFIG); __raw_writel(cfg | 0x100, cbr + BMIPS_RAC_CONFIG); __raw_readl(cbr + BMIPS_RAC_CONFIG); cfg = __raw_readl(cbr + BMIPS_RAC_CONFIG); __raw_writel(cfg | 0xf, cbr + BMIPS_RAC_CONFIG); __raw_readl(cbr + BMIPS_RAC_CONFIG); cfg = __raw_readl(cbr + BMIPS_RAC_ADDRESS_RANGE); __raw_writel(cfg | 0x0fff0000, cbr + BMIPS_RAC_ADDRESS_RANGE); __raw_readl(cbr + BMIPS_RAC_ADDRESS_RANGE); break; case CPU_BMIPS4380: /* CBG workaround for early BMIPS4380 CPUs */ switch (read_c0_prid()) { case 0x2a040: case 0x2a042: case 0x2a044: case 0x2a060: cfg = __raw_readl(cbr + BMIPS_L2_CONFIG); __raw_writel(cfg & ~0x07000000, cbr + BMIPS_L2_CONFIG); __raw_readl(cbr + BMIPS_L2_CONFIG); } /* clear BHTD to enable branch history table */ clear_c0_brcm_config_0(BIT(21)); /* XI/ROTR enable */ set_c0_brcm_config_0(BIT(23)); set_c0_brcm_cmt_ctrl(BIT(15)); break; case CPU_BMIPS5000: /* enable RDHWR, BRDHWR */ set_c0_brcm_config(BIT(17) | BIT(21)); /* Disable JTB */ __asm__ __volatile__( " .set noreorder\n" " li $8, 0x5a455048\n" " .word 0x4088b00f\n" /* mtc0 t0, $22, 15 */ " .word 0x4008b008\n" /* mfc0 t0, $22, 8 */ " li $9, 0x00008000\n" " or $8, $8, $9\n" " .word 0x4088b008\n" /* mtc0 t0, $22, 8 */ " sync\n" " li $8, 0x0\n" " .word 0x4088b00f\n" /* mtc0 t0, $22, 15 */ " .set reorder\n" : : : "$8", "$9"); /* XI enable */ set_c0_brcm_config(BIT(27)); /* enable MIPS32R2 ROR instruction for XI TLB handlers */ __asm__ __volatile__( " li $8, 0x5a455048\n" " .word 0x4088b00f\n" /* mtc0 $8, $22, 15 */ " nop; nop; nop\n" " .word 0x4008b008\n" /* mfc0 $8, $22, 8 */ " lui $9, 0x0100\n" " or $8, $9\n" " .word 0x4088b008\n" /* mtc0 $8, $22, 8 */ : : : "$8", "$9"); break; } }