From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from multi.imgtec.com ([194.200.65.239]:51591 "EHLO multi.imgtec.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753292Ab2LEQJl (ORCPT ); Wed, 5 Dec 2012 11:09:41 -0500 From: James Hogan Subject: [PATCH v2 30/44] metag: SMP support Date: Wed, 5 Dec 2012 16:08:48 +0000 Message-ID: <1354723742-6195-31-git-send-email-james.hogan@imgtec.com> In-Reply-To: <1354723742-6195-1-git-send-email-james.hogan@imgtec.com> References: <1354723742-6195-1-git-send-email-james.hogan@imgtec.com> MIME-Version: 1.0 Content-Type: text/plain Sender: linux-arch-owner@vger.kernel.org List-ID: To: linux-arch@vger.kernel.org, linux-kernel@vger.kernel.org Cc: Arnd Bergmann , James Hogan Message-ID: <20121205160848.skK20aL2aHd7IvTp9cN_8HFDPuq5KTo7wYMov5RQIsQ@z> Add SMP support for metag. This allows Linux to take control of multiple hardware threads on a single Meta core, treating them as separate Linux CPUs. Signed-off-by: James Hogan --- arch/metag/include/asm/cachepart.h | 42 +++ arch/metag/include/asm/core_reg.h | 7 + arch/metag/include/asm/smp.h | 31 ++ arch/metag/include/asm/topology.h | 53 ++++ arch/metag/kernel/cachepart.c | 124 ++++++++ arch/metag/kernel/core_reg.c | 117 +++++++ arch/metag/kernel/head.S | 12 + arch/metag/kernel/smp.c | 582 ++++++++++++++++++++++++++++++++++++ arch/metag/kernel/topology.c | 77 +++++ 9 files changed, 1045 insertions(+), 0 deletions(-) create mode 100644 arch/metag/include/asm/cachepart.h create mode 100644 arch/metag/include/asm/core_reg.h create mode 100644 arch/metag/include/asm/smp.h create mode 100644 arch/metag/include/asm/topology.h create mode 100644 arch/metag/kernel/cachepart.c create mode 100644 arch/metag/kernel/core_reg.c create mode 100644 arch/metag/kernel/smp.c create mode 100644 arch/metag/kernel/topology.c diff --git a/arch/metag/include/asm/cachepart.h b/arch/metag/include/asm/cachepart.h new file mode 100644 index 0000000..cf6b44e --- /dev/null +++ b/arch/metag/include/asm/cachepart.h @@ -0,0 +1,42 @@ +/* + * Meta cache partition manipulation. + * + * Copyright 2010 Imagination Technologies Ltd. + */ + +#ifndef _METAG_CACHEPART_H_ +#define _METAG_CACHEPART_H_ + +/** + * get_dcache_size() - Get size of data cache. + */ +unsigned int get_dcache_size(void); + +/** + * get_icache_size() - Get size of code cache. + */ +unsigned int get_icache_size(void); + +/** + * get_global_dcache_size() - Get the thread's global dcache. + * + * Returns the size of the current thread's global dcache partition. + */ +unsigned int get_global_dcache_size(void); + +/** + * get_global_icache_size() - Get the thread's global icache. + * + * Returns the size of the current thread's global icache partition. + */ +unsigned int get_global_icache_size(void); + +/** + * check_for_dache_aliasing() - Ensure that the bootloader has configured the + * dache and icache properly to avoid aliasing + * @thread_id: Hardware thread ID + * + */ +void check_for_cache_aliasing(int thread_id); + +#endif diff --git a/arch/metag/include/asm/core_reg.h b/arch/metag/include/asm/core_reg.h new file mode 100644 index 0000000..62a4a3a --- /dev/null +++ b/arch/metag/include/asm/core_reg.h @@ -0,0 +1,7 @@ +#ifndef __ASM_METAG_CORE_REG_H_ +#define __ASM_METAG_CORE_REG_H_ + +extern void core_reg_write(int unit, int reg, int thread, unsigned int val); +extern unsigned int core_reg_read(int unit, int reg, int thread); + +#endif diff --git a/arch/metag/include/asm/smp.h b/arch/metag/include/asm/smp.h new file mode 100644 index 0000000..b35fa84 --- /dev/null +++ b/arch/metag/include/asm/smp.h @@ -0,0 +1,31 @@ +#ifndef __ASM_SMP_H +#define __ASM_SMP_H + +#include + +#define raw_smp_processor_id() (current_thread_info()->cpu) + +extern void local_timer_setup(unsigned int cpu); + +enum ipi_msg_type { + IPI_CALL_FUNC, + IPI_CALL_FUNC_SINGLE, + IPI_RESCHEDULE, +}; + +extern void arch_send_call_function_single_ipi(int cpu); +extern void arch_send_call_function_ipi_mask(const struct cpumask *mask); +#define arch_send_call_function_ipi_mask arch_send_call_function_ipi_mask + +asmlinkage void secondary_start_kernel(void); + +extern void secondary_startup(void); + +#ifdef CONFIG_HOTPLUG_CPU +extern void __cpu_die(unsigned int cpu); +extern int __cpu_disable(void); +extern void cpu_die(void); +#endif + +extern void smp_init_cpus(void); +#endif /* __ASM_SMP_H */ diff --git a/arch/metag/include/asm/topology.h b/arch/metag/include/asm/topology.h new file mode 100644 index 0000000..23f5118 --- /dev/null +++ b/arch/metag/include/asm/topology.h @@ -0,0 +1,53 @@ +#ifndef _ASM_METAG_TOPOLOGY_H +#define _ASM_METAG_TOPOLOGY_H + +#ifdef CONFIG_NUMA + +/* sched_domains SD_NODE_INIT for Meta machines */ +#define SD_NODE_INIT (struct sched_domain) { \ + .parent = NULL, \ + .child = NULL, \ + .groups = NULL, \ + .min_interval = 8, \ + .max_interval = 32, \ + .busy_factor = 32, \ + .imbalance_pct = 125, \ + .cache_nice_tries = 2, \ + .busy_idx = 3, \ + .idle_idx = 2, \ + .newidle_idx = 0, \ + .wake_idx = 0, \ + .forkexec_idx = 0, \ + .flags = SD_LOAD_BALANCE \ + | SD_BALANCE_FORK \ + | SD_BALANCE_EXEC \ + | SD_BALANCE_NEWIDLE \ + | SD_SERIALIZE, \ + .last_balance = jiffies, \ + .balance_interval = 1, \ + .nr_balance_failed = 0, \ +} + +#define cpu_to_node(cpu) ((void)(cpu), 0) +#define parent_node(node) ((void)(node), 0) + +#define cpumask_of_node(node) ((void)node, cpu_online_mask) + +#define pcibus_to_node(bus) ((void)(bus), -1) +#define cpumask_of_pcibus(bus) (pcibus_to_node(bus) == -1 ? \ + cpu_all_mask : \ + cpumask_of_node(pcibus_to_node(bus))) + +#endif + +#define mc_capable() (1) + +const struct cpumask *cpu_coregroup_mask(unsigned int cpu); + +extern cpumask_t cpu_core_map[NR_CPUS]; + +#define topology_core_cpumask(cpu) (&cpu_core_map[cpu]) + +#include + +#endif /* _ASM_METAG_TOPOLOGY_H */ diff --git a/arch/metag/kernel/cachepart.c b/arch/metag/kernel/cachepart.c new file mode 100644 index 0000000..3a589dfb --- /dev/null +++ b/arch/metag/kernel/cachepart.c @@ -0,0 +1,124 @@ +/* + * Meta cache partition manipulation. + * + * Copyright 2010 Imagination Technologies Ltd. + */ + +#include +#include +#include +#include +#include +#include +#include + +#define SYSC_DCPART(n) (SYSC_DCPART0 + SYSC_xCPARTn_STRIDE * (n)) +#define SYSC_ICPART(n) (SYSC_ICPART0 + SYSC_xCPARTn_STRIDE * (n)) + +#define CACHE_ASSOCIATIVITY 4 /* 4 way set-assosiative */ +#define ICACHE 0 +#define DCACHE 1 + +/* The CORE_CONFIG2 register is not available on Meta 1 */ +#ifdef CONFIG_METAG_META21 +unsigned int get_dcache_size(void) +{ + unsigned int config2 = metag_in32(METAC_CORE_CONFIG2); + return 0x1000 << ((config2 & METAC_CORECFG2_DCSZ_BITS) + >> METAC_CORECFG2_DCSZ_S); +} + +unsigned int get_icache_size(void) +{ + unsigned int config2 = metag_in32(METAC_CORE_CONFIG2); + return 0x1000 << ((config2 & METAC_CORE_C2ICSZ_BITS) + >> METAC_CORE_C2ICSZ_S); +} + +unsigned int get_global_dcache_size(void) +{ + unsigned int cpart = metag_in32(SYSC_DCPART(hard_processor_id())); + unsigned int temp = cpart & SYSC_xCPARTG_AND_BITS; + return (get_dcache_size() * ((temp >> SYSC_xCPARTG_AND_S) + 1)) >> 4; +} + +unsigned int get_global_icache_size(void) +{ + unsigned int cpart = metag_in32(SYSC_ICPART(hard_processor_id())); + unsigned int temp = cpart & SYSC_xCPARTG_AND_BITS; + return (get_icache_size() * ((temp >> SYSC_xCPARTG_AND_S) + 1)) >> 4; +} + +static unsigned int get_thread_cache_size(unsigned int cache, int thread_id) +{ + unsigned int cache_size; + unsigned int t_cache_part; + unsigned int isEnabled; + unsigned int offset = 0; + isEnabled = (cache == DCACHE ? metag_in32(MMCU_DCACHE_CTRL_ADDR) & 0x1 : + metag_in32(MMCU_ICACHE_CTRL_ADDR) & 0x1); + if (!isEnabled) + return 0; +#if PAGE_OFFSET >= LINGLOBAL_BASE + /* Checking for global cache */ + cache_size = (cache == DCACHE ? get_global_dache_size() : + get_global_icache_size()); + offset = 8; +#else + cache_size = (cache == DCACHE ? get_dcache_size() : + get_icache_size()); +#endif + t_cache_part = (cache == DCACHE ? + (metag_in32(SYSC_DCPART(thread_id)) >> offset) & 0xF : + (metag_in32(SYSC_ICPART(thread_id)) >> offset) & 0xF); + switch (t_cache_part) { + case 0xF: + return cache_size; + case 0x7: + return cache_size / 2; + case 0x3: + return cache_size / 4; + case 0x1: + return cache_size / 8; + case 0: + return cache_size / 16; + } + return -1; +} + +void check_for_cache_aliasing(int thread_id) +{ + unsigned int thread_cache_size; + unsigned int cache_type; + for (cache_type = ICACHE; cache_type <= DCACHE; cache_type++) { + thread_cache_size = + get_thread_cache_size(cache_type, thread_id); + if (thread_cache_size < 0) + pr_emerg("Can't read %s cache size", \ + cache_type ? "DCACHE" : "ICACHE"); + else if (thread_cache_size == 0) + /* Cache is off. No need to check for aliasing */ + continue; + if (thread_cache_size / CACHE_ASSOCIATIVITY > PAGE_SIZE) { + pr_emerg("Cache aliasing detected in %s on Thread %d", + cache_type ? "DCACHE" : "ICACHE", thread_id); + pr_warn("Total %s size: %u bytes", + cache_type ? "DCACHE" : "ICACHE ", + cache_type ? get_dcache_size() + : get_icache_size()); + pr_warn("Thread %s size: %d bytes", + cache_type ? "CACHE" : "ICACHE", + thread_cache_size); + pr_warn("Page Size: %lu bytes", PAGE_SIZE); + } + } +} + +#else + +void check_for_cache_aliasing(int thread_id) +{ + return; +} + +#endif diff --git a/arch/metag/kernel/core_reg.c b/arch/metag/kernel/core_reg.c new file mode 100644 index 0000000..2b40538 --- /dev/null +++ b/arch/metag/kernel/core_reg.c @@ -0,0 +1,117 @@ +/* + * Support for reading and writing Meta core internal registers. + * + * Copyright (C) 2011 Imagination Technologies Ltd. + * + */ + +#include +#include + +#include +#include +#include +#include +#include +#include + +#define UNIT_BIT_MASK TXUXXRXRQ_UXX_BITS +#define REG_BIT_MASK TXUXXRXRQ_RX_BITS +#define THREAD_BIT_MASK TXUXXRXRQ_TX_BITS + +#define UNIT_SHIFTS TXUXXRXRQ_UXX_S +#define REG_SHIFTS TXUXXRXRQ_RX_S +#define THREAD_SHIFTS TXUXXRXRQ_TX_S + +#define UNIT_VAL(x) (((x) << UNIT_SHIFTS) & UNIT_BIT_MASK) +#define REG_VAL(x) (((x) << REG_SHIFTS) & REG_BIT_MASK) +#define THREAD_VAL(x) (((x) << THREAD_SHIFTS) & THREAD_BIT_MASK) + +/* + * core_reg_write() - modify the content of a register in a core unit. + * @unit: The unit to be modified. + * @reg: Register number within the unit. + * @thread: The thread we want to access. + * @val: The new value to write. + * + * Check asm/metag_regs.h for a list/defines of supported units (ie: TXUPC_ID, + * TXUTR_ID, etc), and regnums within the units (ie: TXMASKI_REGNUM, + * TXPOLLI_REGNUM, etc). + */ +void core_reg_write(int unit, int reg, int thread, unsigned int val) +{ + unsigned long flags; + + /* TXUCT_ID has its own memory mapped registers */ + if (unit == TXUCT_ID) { + void __iomem *cu_reg = __CU_addr(thread, reg); + metag_out32(val, cu_reg); + return; + } + + TBI_LOCK(flags); + + /* wait for ready */ + while (!(metag_in32(TXUXXRXRQ) & TXUXXRXRQ_DREADY_BIT)) + udelay(10); + + /* set the value to write */ + metag_out32(val, TXUXXRXDT); + + /* set the register to write */ + val = UNIT_VAL(unit) | REG_VAL(reg) | THREAD_VAL(thread); + metag_out32(val, TXUXXRXRQ); + + /* wait for finish */ + while (!(metag_in32(TXUXXRXRQ) & TXUXXRXRQ_DREADY_BIT)) + udelay(10); + + TBI_UNLOCK(flags); +} +EXPORT_SYMBOL(core_reg_write); + +/* + * core_reg_read() - read the content of a register in a core unit. + * @unit: The unit to be modified. + * @reg: Register number within the unit. + * @thread: The thread we want to access. + * + * Check asm/metag_regs.h for a list/defines of supported units (ie: TXUPC_ID, + * TXUTR_ID, etc), and regnums within the units (ie: TXMASKI_REGNUM, + * TXPOLLI_REGNUM, etc). + */ +unsigned int core_reg_read(int unit, int reg, int thread) +{ + unsigned long flags; + unsigned int val; + + /* TXUCT_ID has its own memory mapped registers */ + if (unit == TXUCT_ID) { + void __iomem *cu_reg = __CU_addr(thread, reg); + val = metag_in32(cu_reg); + return val; + } + + TBI_LOCK(flags); + + /* wait for ready */ + while (!(metag_in32(TXUXXRXRQ) & TXUXXRXRQ_DREADY_BIT)) + udelay(10); + + /* set the register to read */ + val = (UNIT_VAL(unit) | REG_VAL(reg) | THREAD_VAL(thread) | + TXUXXRXRQ_RDnWR_BIT); + metag_out32(val, TXUXXRXRQ); + + /* wait for finish */ + while (!(metag_in32(TXUXXRXRQ) & TXUXXRXRQ_DREADY_BIT)) + udelay(10); + + /* read the register value */ + val = metag_in32(TXUXXRXDT); + + TBI_UNLOCK(flags); + + return val; +} +EXPORT_SYMBOL(core_reg_read); diff --git a/arch/metag/kernel/head.S b/arch/metag/kernel/head.S index 8b13886..969dffa 100644 --- a/arch/metag/kernel/head.S +++ b/arch/metag/kernel/head.S @@ -43,3 +43,15 @@ __start: __exit: XOR TXENABLE,D0Re0,D0Re0 .size __exit,.-__exit + +#ifdef CONFIG_SMP + .global _secondary_startup + .type _secondary_startup,function +_secondary_startup: + MOVT A0StP,#HI(_secondary_data_stack) + ADD A0StP,A0StP,#LO(_secondary_data_stack) + GETD A0StP,[A0StP] + ADD A0StP,A0StP,#THREAD_INFO_SIZE + B _secondary_start_kernel + .size _secondary_startup,.-_secondary_startup +#endif diff --git a/arch/metag/kernel/smp.c b/arch/metag/kernel/smp.c new file mode 100644 index 0000000..92335fe --- /dev/null +++ b/arch/metag/kernel/smp.c @@ -0,0 +1,582 @@ +/* + * Copyright (C) 2009,2010,2011 Imagination Technologies Ltd. + * + * Copyright (C) 2002 ARM Limited, All Rights Reserved. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + */ +#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 + +DECLARE_PER_CPU(PTBI, pTBI); + +void *secondary_data_stack; + +/* + * structures for inter-processor calls + * - A collection of single bit ipi messages. + */ +struct ipi_data { + spinlock_t lock; + unsigned long ipi_count; + unsigned long bits; +}; + +static DEFINE_PER_CPU(struct ipi_data, ipi_data) = { + .lock = __SPIN_LOCK_UNLOCKED(ipi_data.lock), +}; + +static DEFINE_SPINLOCK(boot_lock); + +/* + * "thread" is assumed to be a valid Meta hardware thread ID. + */ +int __cpuinit boot_secondary(unsigned int thread, struct task_struct *idle) +{ + u32 val; + + /* + * set synchronisation state between this boot processor + * and the secondary one + */ + spin_lock(&boot_lock); + + core_reg_write(TXUPC_ID, 0, thread, (unsigned int)secondary_startup); + core_reg_write(TXUPC_ID, 1, thread, 0); + + /* + * Give the thread privilege (PSTAT) and clear potentially problematic + * bits in the process (namely ISTAT, CBMarker, CBMarkerI, LSM_STEP). + */ + core_reg_write(TXUCT_ID, TXSTATUS_REGNUM, thread, TXSTATUS_PSTAT_BIT); + + /* Clear the minim enable bit. */ + val = core_reg_read(TXUCT_ID, TXPRIVEXT_REGNUM, thread); + core_reg_write(TXUCT_ID, TXPRIVEXT_REGNUM, thread, val & ~0x80); + + /* + * set the ThreadEnable bit (0x1) in the TXENABLE register + * for the specified thread - off it goes! + */ + val = core_reg_read(TXUCT_ID, TXENABLE_REGNUM, thread); + core_reg_write(TXUCT_ID, TXENABLE_REGNUM, thread, val | 0x1); + + /* + * now the secondary core is starting up let it run its + * calibrations, then wait for it to finish + */ + spin_unlock(&boot_lock); + + return 0; +} + +int __cpuinit __cpu_up(unsigned int cpu, struct task_struct *idle) +{ + unsigned int thread = cpu_2_hwthread_id[cpu]; + int ret; + + load_pgd(swapper_pg_dir, thread); + + flush_tlb_all(); + + /* + * Tell the secondary CPU where to find its idle threads's stack. + */ + secondary_data_stack = task_stack_page(idle); + + wmb(); + + /* + * Now bring the CPU into our world. + */ + ret = boot_secondary(thread, idle); + if (ret == 0) { + unsigned long timeout; + + /* + * CPU was successfully started, wait for it + * to come online or time out. + */ + timeout = jiffies + HZ; + while (time_before(jiffies, timeout)) { + if (cpu_online(cpu)) + break; + + udelay(10); + barrier(); + } + + if (!cpu_online(cpu)) + ret = -EIO; + } + + secondary_data_stack = NULL; + + if (ret) { + pr_crit("CPU%u: processor failed to boot\n", cpu); + + /* + * FIXME: We need to clean up the new idle thread. --rmk + */ + } + + return ret; +} + +#ifdef CONFIG_HOTPLUG_CPU +static DECLARE_COMPLETION(cpu_killed); + +/* + * __cpu_disable runs on the processor to be shutdown. + */ +int __cpuexit __cpu_disable(void) +{ + unsigned int cpu = smp_processor_id(); + struct task_struct *p; + + /* + * Take this CPU offline. Once we clear this, we can't return, + * and we must not schedule until we're ready to give up the cpu. + */ + set_cpu_online(cpu, false); + + /* + * OK - migrate IRQs away from this CPU + */ + migrate_irqs(); + + /* + * Flush user cache and TLB mappings, and then remove this CPU + * from the vm mask set of all processes. + */ + flush_cache_all(); + local_flush_tlb_all(); + + read_lock(&tasklist_lock); + for_each_process(p) { + if (p->mm) + cpumask_clear_cpu(cpu, mm_cpumask(p->mm)); + } + read_unlock(&tasklist_lock); + + return 0; +} + +/* + * called on the thread which is asking for a CPU to be shutdown - + * waits until shutdown has completed, or it is timed out. + */ +void __cpuexit __cpu_die(unsigned int cpu) +{ + if (!wait_for_completion_timeout(&cpu_killed, msecs_to_jiffies(1))) + pr_err("CPU%u: unable to kill\n", cpu); +} + +/* + * Called from the idle thread for the CPU which has been shutdown. + * + * Note that we do not return from this function. If this cpu is + * brought online again it will need to run secondary_startup(). + */ +void __cpuexit cpu_die(void) +{ + local_irq_disable(); + idle_task_exit(); + + complete(&cpu_killed); + + __asm__("XOR TXENABLE, D0Re0,D0Re0\n"); +} +#endif /* CONFIG_HOTPLUG_CPU */ + +/* + * Called by both boot and secondaries to move global data into + * per-processor storage. + */ +void __cpuinit smp_store_cpu_info(unsigned int cpuid) +{ + struct cpuinfo_metag *cpu_info = &per_cpu(cpu_data, cpuid); + + cpu_info->loops_per_jiffy = loops_per_jiffy; +} + +/* + * This is the secondary CPU boot entry. We're using this CPUs + * idle thread stack and the global page tables. + */ +asmlinkage void secondary_start_kernel(void) +{ + struct mm_struct *mm = &init_mm; + unsigned int cpu = smp_processor_id(); + + /* + * All kernel threads share the same mm context; grab a + * reference and switch to it. + */ + atomic_inc(&mm->mm_users); + atomic_inc(&mm->mm_count); + current->active_mm = mm; + cpumask_set_cpu(cpu, mm_cpumask(mm)); + enter_lazy_tlb(mm, current); + local_flush_tlb_all(); + + /* + * TODO: Some day it might be useful for each Linux CPU to + * have its own TBI structure. That would allow each Linux CPU + * to run different interrupt handlers for the same IRQ + * number. + * + * For now, simply copying the pointer to the boot CPU's TBI + * structure is sufficient because we always want to run the + * same interrupt handler whatever CPU takes the interrupt. + */ + per_cpu(pTBI, cpu) = __TBI(TBID_ISTAT_BIT); + + if (!per_cpu(pTBI, cpu)) + panic("No TBI found!"); + + per_cpu_trap_init(cpu); + + preempt_disable(); + + setup_txprivext(); + + /* + * Enable local interrupts. + */ + tbi_startup_interrupt(TBID_SIGNUM_TRT); + notify_cpu_starting(cpu); + local_irq_enable(); + + /* + * Start local timers for this CPU. + */ + local_timer_setup(cpu); + + pr_info("CPU%u (thread %u): Booted secondary processor\n", + cpu, cpu_2_hwthread_id[cpu]); + + calibrate_delay(); + smp_store_cpu_info(cpu); + + /* + * OK, now it's safe to let the boot CPU continue + */ + notify_cpu_starting(cpu); + + set_cpu_online(cpu, true); + + /* + * Check for cache aliasing. + * Preemption is disabled + */ + check_for_cache_aliasing(cpu); + + /* + * OK, it's off to the idle thread for us + */ + cpu_idle(); +} + +void __init smp_cpus_done(unsigned int max_cpus) +{ + int cpu; + unsigned long bogosum = 0; + + for_each_online_cpu(cpu) + bogosum += per_cpu(cpu_data, cpu).loops_per_jiffy; + + pr_info("SMP: Total of %d processors activated (%lu.%02lu BogoMIPS).\n", + num_online_cpus(), + bogosum / (500000/HZ), + (bogosum / (5000/HZ)) % 100); +} + +void __init smp_prepare_cpus(unsigned int max_cpus) +{ + unsigned int cpu = smp_processor_id(); + + init_new_context(current, &init_mm); + current_thread_info()->cpu = cpu; + + smp_store_cpu_info(cpu); + init_cpu_present(cpu_possible_mask); +} + +void __init smp_prepare_boot_cpu(void) +{ + unsigned int cpu = smp_processor_id(); + + per_cpu(pTBI, cpu) = __TBI(TBID_ISTAT_BIT); + + if (!per_cpu(pTBI, cpu)) + panic("No TBI found!"); +} + +static void smp_cross_call(cpumask_t callmap, enum ipi_msg_type msg); + +static void send_ipi_message(const struct cpumask *mask, enum ipi_msg_type msg) +{ + unsigned long flags; + unsigned int cpu; + cpumask_t map; + + cpumask_clear(&map); + local_irq_save(flags); + + for_each_cpu(cpu, mask) { + struct ipi_data *ipi = &per_cpu(ipi_data, cpu); + + spin_lock(&ipi->lock); + + /* + * KICK interrupts are queued in hardware so we'll get + * multiple interrupts if we call smp_cross_call() + * multiple times for one msg. The problem is that we + * only have one bit for each message - we can't queue + * them in software. + * + * The first time through ipi_handler() we'll clear + * the msg bit, having done all the work. But when we + * return we'll get _another_ interrupt (and another, + * and another until we've handled all the queued + * KICKs). Running ipi_handler() when there's no work + * to do is bad because that's how kick handler + * chaining detects who the KICK was intended for. + * See arch/metag/kernel/kick.c for more details. + * + * So only add 'cpu' to 'map' if we haven't already + * queued a KICK interrupt for 'msg'. + */ + if (!(ipi->bits & (1 << msg))) { + ipi->bits |= 1 << msg; + cpumask_set_cpu(cpu, &map); + } + + spin_unlock(&ipi->lock); + } + + /* + * Call the platform specific cross-CPU call function. + */ + smp_cross_call(map, msg); + + local_irq_restore(flags); +} + +void arch_send_call_function_ipi_mask(const struct cpumask *mask) +{ + send_ipi_message(mask, IPI_CALL_FUNC); +} + +void arch_send_call_function_single_ipi(int cpu) +{ + send_ipi_message(cpumask_of(cpu), IPI_CALL_FUNC_SINGLE); +} + +void show_ipi_list(struct seq_file *p) +{ + unsigned int cpu; + + seq_puts(p, "IPI:"); + + for_each_present_cpu(cpu) + seq_printf(p, " %10lu", per_cpu(ipi_data, cpu).ipi_count); + + seq_putc(p, '\n'); +} + +static DEFINE_SPINLOCK(stop_lock); + +/* + * Main handler for inter-processor interrupts + * + * For Meta, the ipimask now only identifies a single + * category of IPI (Bit 1 IPIs have been replaced by a + * different mechanism): + * + * Bit 0 - Inter-processor function call + */ +static int do_IPI(struct pt_regs *regs) +{ + unsigned int cpu = smp_processor_id(); + struct ipi_data *ipi = &per_cpu(ipi_data, cpu); + struct pt_regs *old_regs = set_irq_regs(regs); + unsigned long msgs, nextmsg; + int handled = 0; + + ipi->ipi_count++; + + spin_lock(&ipi->lock); + msgs = ipi->bits; + nextmsg = msgs & -msgs; + ipi->bits &= ~nextmsg; + spin_unlock(&ipi->lock); + + if (nextmsg) { + handled = 1; + + nextmsg = ffz(~nextmsg); + switch (nextmsg) { + case IPI_RESCHEDULE: + scheduler_ipi(); + break; + + case IPI_CALL_FUNC: + generic_smp_call_function_interrupt(); + break; + + case IPI_CALL_FUNC_SINGLE: + generic_smp_call_function_single_interrupt(); + break; + + default: + pr_crit("CPU%u: Unknown IPI message 0x%lx\n", + cpu, nextmsg); + break; + } + } + + set_irq_regs(old_regs); + + return handled; +} + +void smp_send_reschedule(int cpu) +{ + send_ipi_message(cpumask_of(cpu), IPI_RESCHEDULE); +} + +static void stop_this_cpu(void *data) +{ + unsigned int cpu = smp_processor_id(); + + if (system_state == SYSTEM_BOOTING || + system_state == SYSTEM_RUNNING) { + spin_lock(&stop_lock); + pr_crit("CPU%u: stopping\n", cpu); + dump_stack(); + spin_unlock(&stop_lock); + } + + set_cpu_online(cpu, false); + + local_irq_disable(); + + hard_processor_halt(HALT_OK); +} + +void smp_send_stop(void) +{ + smp_call_function(stop_this_cpu, NULL, 0); +} + +/* + * not supported here + */ +int setup_profiling_timer(unsigned int multiplier) +{ + return -EINVAL; +} + +/* + * We use KICKs for inter-processor interrupts. + * + * For every CPU in "callmap" the IPI data must already have been + * stored in that CPU's "ipi_data" member prior to calling this + * function. + */ +static void kick_raise_softirq(cpumask_t callmap, unsigned int irq) +{ + int cpu; + + for_each_cpu(cpu, &callmap) { + unsigned int thread; + + thread = cpu_2_hwthread_id[cpu]; + + BUG_ON(thread == BAD_HWTHREAD_ID); + + metag_out32(1, T0KICKI + (thread * TnXKICK_STRIDE)); + } +} + +static TBIRES ipi_handler(TBIRES State, int SigNum, int Triggers, + int Inst, PTBI pTBI, int *handled) +{ + *handled = do_IPI((struct pt_regs *)State.Sig.pCtx); + + return State; +} + +static struct kick_irq_handler ipi_irq = { + .func = ipi_handler, +}; + +static void smp_cross_call(cpumask_t callmap, enum ipi_msg_type msg) +{ + kick_raise_softirq(callmap, 1); +} + +static inline unsigned int get_core_count(void) +{ + int i; + unsigned int ret = 0; + + for (i = 0; i < CONFIG_NR_CPUS; i++) { + if (core_reg_read(TXUCT_ID, TXENABLE_REGNUM, i)) + ret++; + } + + return ret; +} + +/* + * Initialise the CPU possible map early - this describes the CPUs + * which may be present or become present in the system. + */ +void __init smp_init_cpus(void) +{ + unsigned int i, ncores = get_core_count(); + + /* If no hwthread_map early param was set use default mapping */ + for (i = 0; i < NR_CPUS; i++) + if (cpu_2_hwthread_id[i] == BAD_HWTHREAD_ID) { + cpu_2_hwthread_id[i] = i; + hwthread_id_2_cpu[i] = i; + } + + for (i = 0; i < ncores; i++) + set_cpu_possible(i, true); + + kick_register_func(&ipi_irq); +} diff --git a/arch/metag/kernel/topology.c b/arch/metag/kernel/topology.c new file mode 100644 index 0000000..bec3dec --- /dev/null +++ b/arch/metag/kernel/topology.c @@ -0,0 +1,77 @@ +/* + * Copyright (C) 2007 Paul Mundt + * Copyright (C) 2010 Imagination Technolohies Ltd. + * + * 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. + */ +#include +#include +#include +#include +#include +#include +#include + +#include + +DEFINE_PER_CPU(struct cpuinfo_metag, cpu_data); + +cpumask_t cpu_core_map[NR_CPUS]; + +static cpumask_t cpu_coregroup_map(unsigned int cpu) +{ + return *cpu_possible_mask; +} + +const struct cpumask *cpu_coregroup_mask(unsigned int cpu) +{ + return &cpu_core_map[cpu]; +} + +int arch_update_cpu_topology(void) +{ + unsigned int cpu; + + for_each_possible_cpu(cpu) + cpu_core_map[cpu] = cpu_coregroup_map(cpu); + + return 0; +} + +static int __init topology_init(void) +{ + int i, ret; + +#ifdef CONFIG_NEED_MULTIPLE_NODES + for_each_online_node(i) + register_one_node(i); +#endif + + for_each_present_cpu(i) { + struct cpuinfo_metag *cpuinfo = &per_cpu(cpu_data, i); +#ifdef CONFIG_HOTPLUG_CPU + cpuinfo->cpu.hotpluggable = 1; +#endif + ret = register_cpu(&cpuinfo->cpu, i); + if (unlikely(ret)) + pr_warn("%s: register_cpu %d failed (%d)\n", + __func__, i, ret); + } + +#if defined(CONFIG_NUMA) && !defined(CONFIG_SMP) + /* + * In the UP case, make sure the CPU association is still + * registered under each node. Without this, sysfs fails + * to make the connection between nodes other than node0 + * and cpu0. + */ + for_each_online_node(i) + if (i != numa_node_id()) + register_cpu_under_node(raw_smp_processor_id(), i); +#endif + + return 0; +} +subsys_initcall(topology_init); -- 1.7.7.6