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Diffstat (limited to 'arch/mips/kernel/smtc.c')
| -rw-r--r-- | arch/mips/kernel/smtc.c | 1528 |
1 files changed, 0 insertions, 1528 deletions
diff --git a/arch/mips/kernel/smtc.c b/arch/mips/kernel/smtc.c deleted file mode 100644 index c1681d65dd5c..000000000000 --- a/arch/mips/kernel/smtc.c +++ /dev/null @@ -1,1528 +0,0 @@ -/* - * This program is free software; you can redistribute it and/or - * modify it under the terms of the GNU General Public License - * as published by the Free Software Foundation; either version 2 - * of the License, or (at your option) any later version. - * - * This program is distributed in the hope that it will be useful, - * but WITHOUT ANY WARRANTY; without even the implied warranty of - * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the - * GNU General Public License for more details. - * - * You should have received a copy of the GNU General Public License - * along with this program; if not, write to the Free Software - * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. - * - * Copyright (C) 2004 Mips Technologies, Inc - * Copyright (C) 2008 Kevin D. Kissell - */ - -#include <linux/clockchips.h> -#include <linux/kernel.h> -#include <linux/sched.h> -#include <linux/smp.h> -#include <linux/cpumask.h> -#include <linux/interrupt.h> -#include <linux/kernel_stat.h> -#include <linux/module.h> -#include <linux/ftrace.h> -#include <linux/slab.h> - -#include <asm/cpu.h> -#include <asm/processor.h> -#include <linux/atomic.h> -#include <asm/hardirq.h> -#include <asm/hazards.h> -#include <asm/irq.h> -#include <asm/idle.h> -#include <asm/mmu_context.h> -#include <asm/mipsregs.h> -#include <asm/cacheflush.h> -#include <asm/time.h> -#include <asm/addrspace.h> -#include <asm/smtc.h> -#include <asm/smtc_proc.h> -#include <asm/setup.h> - -/* - * SMTC Kernel needs to manipulate low-level CPU interrupt mask - * in do_IRQ. These are passed in setup_irq_smtc() and stored - * in this table. - */ -unsigned long irq_hwmask[NR_IRQS]; - -#define LOCK_MT_PRA() \ - local_irq_save(flags); \ - mtflags = dmt() - -#define UNLOCK_MT_PRA() \ - emt(mtflags); \ - local_irq_restore(flags) - -#define LOCK_CORE_PRA() \ - local_irq_save(flags); \ - mtflags = dvpe() - -#define UNLOCK_CORE_PRA() \ - evpe(mtflags); \ - local_irq_restore(flags) - -/* - * Data structures purely associated with SMTC parallelism - */ - - -/* - * Table for tracking ASIDs whose lifetime is prolonged. - */ - -asiduse smtc_live_asid[MAX_SMTC_TLBS][MAX_SMTC_ASIDS]; - -/* - * Number of InterProcessor Interrupt (IPI) message buffers to allocate - */ - -#define IPIBUF_PER_CPU 4 - -struct smtc_ipi_q IPIQ[NR_CPUS]; -static struct smtc_ipi_q freeIPIq; - - -/* - * Number of FPU contexts for each VPE - */ - -static int smtc_nconf1[MAX_SMTC_VPES]; - - -/* Forward declarations */ - -void ipi_decode(struct smtc_ipi *); -static void post_direct_ipi(int cpu, struct smtc_ipi *pipi); -static void setup_cross_vpe_interrupts(unsigned int nvpe); -void init_smtc_stats(void); - -/* Global SMTC Status */ - -unsigned int smtc_status; - -/* Boot command line configuration overrides */ - -static int vpe0limit; -static int ipibuffers; -static int nostlb; -static int asidmask; -unsigned long smtc_asid_mask = 0xff; - -static int __init vpe0tcs(char *str) -{ - get_option(&str, &vpe0limit); - - return 1; -} - -static int __init ipibufs(char *str) -{ - get_option(&str, &ipibuffers); - return 1; -} - -static int __init stlb_disable(char *s) -{ - nostlb = 1; - return 1; -} - -static int __init asidmask_set(char *str) -{ - get_option(&str, &asidmask); - switch (asidmask) { - case 0x1: - case 0x3: - case 0x7: - case 0xf: - case 0x1f: - case 0x3f: - case 0x7f: - case 0xff: - smtc_asid_mask = (unsigned long)asidmask; - break; - default: - printk("ILLEGAL ASID mask 0x%x from command line\n", asidmask); - } - return 1; -} - -__setup("vpe0tcs=", vpe0tcs); -__setup("ipibufs=", ipibufs); -__setup("nostlb", stlb_disable); -__setup("asidmask=", asidmask_set); - -#ifdef CONFIG_SMTC_IDLE_HOOK_DEBUG - -static int hang_trig; - -static int __init hangtrig_enable(char *s) -{ - hang_trig = 1; - return 1; -} - - -__setup("hangtrig", hangtrig_enable); - -#define DEFAULT_BLOCKED_IPI_LIMIT 32 - -static int timerq_limit = DEFAULT_BLOCKED_IPI_LIMIT; - -static int __init tintq(char *str) -{ - get_option(&str, &timerq_limit); - return 1; -} - -__setup("tintq=", tintq); - -static int imstuckcount[MAX_SMTC_VPES][8]; -/* vpemask represents IM/IE bits of per-VPE Status registers, low-to-high */ -static int vpemask[MAX_SMTC_VPES][8] = { - {0, 0, 1, 0, 0, 0, 0, 1}, - {0, 0, 0, 0, 0, 0, 0, 1} -}; -int tcnoprog[NR_CPUS]; -static atomic_t idle_hook_initialized = ATOMIC_INIT(0); -static int clock_hang_reported[NR_CPUS]; - -#endif /* CONFIG_SMTC_IDLE_HOOK_DEBUG */ - -/* - * Configure shared TLB - VPC configuration bit must be set by caller - */ - -static void smtc_configure_tlb(void) -{ - int i, tlbsiz, vpes; - unsigned long mvpconf0; - unsigned long config1val; - - /* Set up ASID preservation table */ - for (vpes=0; vpes<MAX_SMTC_TLBS; vpes++) { - for(i = 0; i < MAX_SMTC_ASIDS; i++) { - smtc_live_asid[vpes][i] = 0; - } - } - mvpconf0 = read_c0_mvpconf0(); - - if ((vpes = ((mvpconf0 & MVPCONF0_PVPE) - >> MVPCONF0_PVPE_SHIFT) + 1) > 1) { - /* If we have multiple VPEs, try to share the TLB */ - if ((mvpconf0 & MVPCONF0_TLBS) && !nostlb) { - /* - * If TLB sizing is programmable, shared TLB - * size is the total available complement. - * Otherwise, we have to take the sum of all - * static VPE TLB entries. - */ - if ((tlbsiz = ((mvpconf0 & MVPCONF0_PTLBE) - >> MVPCONF0_PTLBE_SHIFT)) == 0) { - /* - * If there's more than one VPE, there had better - * be more than one TC, because we need one to bind - * to each VPE in turn to be able to read - * its configuration state! - */ - settc(1); - /* Stop the TC from doing anything foolish */ - write_tc_c0_tchalt(TCHALT_H); - mips_ihb(); - /* No need to un-Halt - that happens later anyway */ - for (i=0; i < vpes; i++) { - write_tc_c0_tcbind(i); - /* - * To be 100% sure we're really getting the right - * information, we exit the configuration state - * and do an IHB after each rebinding. - */ - write_c0_mvpcontrol( - read_c0_mvpcontrol() & ~ MVPCONTROL_VPC ); - mips_ihb(); - /* - * Only count if the MMU Type indicated is TLB - */ - if (((read_vpe_c0_config() & MIPS_CONF_MT) >> 7) == 1) { - config1val = read_vpe_c0_config1(); - tlbsiz += ((config1val >> 25) & 0x3f) + 1; - } - - /* Put core back in configuration state */ - write_c0_mvpcontrol( - read_c0_mvpcontrol() | MVPCONTROL_VPC ); - mips_ihb(); - } - } - write_c0_mvpcontrol(read_c0_mvpcontrol() | MVPCONTROL_STLB); - ehb(); - - /* - * Setup kernel data structures to use software total, - * rather than read the per-VPE Config1 value. The values - * for "CPU 0" gets copied to all the other CPUs as part - * of their initialization in smtc_cpu_setup(). - */ - - /* MIPS32 limits TLB indices to 64 */ - if (tlbsiz > 64) - tlbsiz = 64; - cpu_data[0].tlbsize = current_cpu_data.tlbsize = tlbsiz; - smtc_status |= SMTC_TLB_SHARED; - local_flush_tlb_all(); - - printk("TLB of %d entry pairs shared by %d VPEs\n", - tlbsiz, vpes); - } else { - printk("WARNING: TLB Not Sharable on SMTC Boot!\n"); - } - } -} - - -/* - * Incrementally build the CPU map out of constituent MIPS MT cores, - * using the specified available VPEs and TCs. Plaform code needs - * to ensure that each MIPS MT core invokes this routine on reset, - * one at a time(!). - * - * This version of the build_cpu_map and prepare_cpus routines assumes - * that *all* TCs of a MIPS MT core will be used for Linux, and that - * they will be spread across *all* available VPEs (to minimise the - * loss of efficiency due to exception service serialization). - * An improved version would pick up configuration information and - * possibly leave some TCs/VPEs as "slave" processors. - * - * Use c0_MVPConf0 to find out how many TCs are available, setting up - * cpu_possible_mask and the logical/physical mappings. - */ - -int __init smtc_build_cpu_map(int start_cpu_slot) -{ - int i, ntcs; - - /* - * The CPU map isn't actually used for anything at this point, - * so it's not clear what else we should do apart from set - * everything up so that "logical" = "physical". - */ - ntcs = ((read_c0_mvpconf0() & MVPCONF0_PTC) >> MVPCONF0_PTC_SHIFT) + 1; - for (i=start_cpu_slot; i<NR_CPUS && i<ntcs; i++) { - set_cpu_possible(i, true); - __cpu_number_map[i] = i; - __cpu_logical_map[i] = i; - } -#ifdef CONFIG_MIPS_MT_FPAFF - /* Initialize map of CPUs with FPUs */ - cpus_clear(mt_fpu_cpumask); -#endif - - /* One of those TC's is the one booting, and not a secondary... */ - printk("%i available secondary CPU TC(s)\n", i - 1); - - return i; -} - -/* - * Common setup before any secondaries are started - * Make sure all CPUs are in a sensible state before we boot any of the - * secondaries. - * - * For MIPS MT "SMTC" operation, we set up all TCs, spread as evenly - * as possible across the available VPEs. - */ - -static void smtc_tc_setup(int vpe, int tc, int cpu) -{ - static int cp1contexts[MAX_SMTC_VPES]; - - /* - * Make a local copy of the available FPU contexts in order - * to keep track of TCs that can have one. - */ - if (tc == 1) - { - /* - * FIXME: Multi-core SMTC hasn't been tested and the - * maximum number of VPEs may change. - */ - cp1contexts[0] = smtc_nconf1[0] - 1; - cp1contexts[1] = smtc_nconf1[1]; - } - - settc(tc); - write_tc_c0_tchalt(TCHALT_H); - mips_ihb(); - write_tc_c0_tcstatus((read_tc_c0_tcstatus() - & ~(TCSTATUS_TKSU | TCSTATUS_DA | TCSTATUS_IXMT)) - | TCSTATUS_A); - /* - * TCContext gets an offset from the base of the IPIQ array - * to be used in low-level code to detect the presence of - * an active IPI queue. - */ - write_tc_c0_tccontext((sizeof(struct smtc_ipi_q) * cpu) << 16); - - /* Bind TC to VPE. */ - write_tc_c0_tcbind(vpe); - - /* In general, all TCs should have the same cpu_data indications. */ - memcpy(&cpu_data[cpu], &cpu_data[0], sizeof(struct cpuinfo_mips)); - - /* Check to see if there is a FPU context available for this TC. */ - if (!cp1contexts[vpe]) - cpu_data[cpu].options &= ~MIPS_CPU_FPU; - else - cp1contexts[vpe]--; - - /* Store the TC and VPE into the cpu_data structure. */ - cpu_data[cpu].vpe_id = vpe; - cpu_data[cpu].tc_id = tc; - - /* FIXME: Multi-core SMTC hasn't been tested, but be prepared. */ - cpu_data[cpu].core = (read_vpe_c0_ebase() >> 1) & 0xff; -} - -/* - * Tweak to get Count registers synced as closely as possible. The - * value seems good for 34K-class cores. - */ - -#define CP0_SKEW 8 - -void smtc_prepare_cpus(int cpus) -{ - int i, vpe, tc, ntc, nvpe, tcpervpe[NR_CPUS], slop, cpu; - unsigned long flags; - unsigned long val; - int nipi; - struct smtc_ipi *pipi; - - /* disable interrupts so we can disable MT */ - local_irq_save(flags); - /* disable MT so we can configure */ - dvpe(); - dmt(); - - spin_lock_init(&freeIPIq.lock); - - /* - * We probably don't have as many VPEs as we do SMP "CPUs", - * but it's possible - and in any case we'll never use more! - */ - for (i=0; i<NR_CPUS; i++) { - IPIQ[i].head = IPIQ[i].tail = NULL; - spin_lock_init(&IPIQ[i].lock); - IPIQ[i].depth = 0; - IPIQ[i].resched_flag = 0; /* No reschedules queued initially */ - } - - /* cpu_data index starts at zero */ - cpu = 0; - cpu_data[cpu].vpe_id = 0; - cpu_data[cpu].tc_id = 0; - cpu_data[cpu].core = (read_c0_ebase() >> 1) & 0xff; - cpu++; - - /* Report on boot-time options */ - mips_mt_set_cpuoptions(); - if (vpelimit > 0) - printk("Limit of %d VPEs set\n", vpelimit); - if (tclimit > 0) - printk("Limit of %d TCs set\n", tclimit); - if (nostlb) { - printk("Shared TLB Use Inhibited - UNSAFE for Multi-VPE Operation\n"); - } - if (asidmask) - printk("ASID mask value override to 0x%x\n", asidmask); - - /* Temporary */ -#ifdef CONFIG_SMTC_IDLE_HOOK_DEBUG - if (hang_trig) - printk("Logic Analyser Trigger on suspected TC hang\n"); -#endif /* CONFIG_SMTC_IDLE_HOOK_DEBUG */ - - /* Put MVPE's into 'configuration state' */ - write_c0_mvpcontrol( read_c0_mvpcontrol() | MVPCONTROL_VPC ); - - val = read_c0_mvpconf0(); - nvpe = ((val & MVPCONF0_PVPE) >> MVPCONF0_PVPE_SHIFT) + 1; - if (vpelimit > 0 && nvpe > vpelimit) - nvpe = vpelimit; - ntc = ((val & MVPCONF0_PTC) >> MVPCONF0_PTC_SHIFT) + 1; - if (ntc > NR_CPUS) - ntc = NR_CPUS; - if (tclimit > 0 && ntc > tclimit) - ntc = tclimit; - slop = ntc % nvpe; - for (i = 0; i < nvpe; i++) { - tcpervpe[i] = ntc / nvpe; - if (slop) { - if((slop - i) > 0) tcpervpe[i]++; - } - } - /* Handle command line override for VPE0 */ - if (vpe0limit > ntc) vpe0limit = ntc; - if (vpe0limit > 0) { - int slopslop; - if (vpe0limit < tcpervpe[0]) { - /* Reducing TC count - distribute to others */ - slop = tcpervpe[0] - vpe0limit; - slopslop = slop % (nvpe - 1); - tcpervpe[0] = vpe0limit; - for (i = 1; i < nvpe; i++) { - tcpervpe[i] += slop / (nvpe - 1); - if(slopslop && ((slopslop - (i - 1) > 0))) - tcpervpe[i]++; - } - } else if (vpe0limit > tcpervpe[0]) { - /* Increasing TC count - steal from others */ - slop = vpe0limit - tcpervpe[0]; - slopslop = slop % (nvpe - 1); - tcpervpe[0] = vpe0limit; - for (i = 1; i < nvpe; i++) { - tcpervpe[i] -= slop / (nvpe - 1); - if(slopslop && ((slopslop - (i - 1) > 0))) - tcpervpe[i]--; - } - } - } - - /* Set up shared TLB */ - smtc_configure_tlb(); - - for (tc = 0, vpe = 0 ; (vpe < nvpe) && (tc < ntc) ; vpe++) { - /* Get number of CP1 contexts for each VPE. */ - if (tc == 0) - { - /* - * Do not call settc() for TC0 or the FPU context - * value will be incorrect. Besides, we know that - * we are TC0 anyway. - */ - smtc_nconf1[0] = ((read_vpe_c0_vpeconf1() & - VPECONF1_NCP1) >> VPECONF1_NCP1_SHIFT); - if (nvpe == 2) - { - settc(1); - smtc_nconf1[1] = ((read_vpe_c0_vpeconf1() & - VPECONF1_NCP1) >> VPECONF1_NCP1_SHIFT); - settc(0); - } - } - if (tcpervpe[vpe] == 0) - continue; - if (vpe != 0) - printk(", "); - printk("VPE %d: TC", vpe); - for (i = 0; i < tcpervpe[vpe]; i++) { - /* - * TC 0 is bound to VPE 0 at reset, - * and is presumably executing this - * code. Leave it alone! - */ - if (tc != 0) { - smtc_tc_setup(vpe, tc, cpu); - if (vpe != 0) { - /* - * Set MVP bit (possibly again). Do it - * here to catch CPUs that have no TCs - * bound to the VPE at reset. In that - * case, a TC must be bound to the VPE - * before we can set VPEControl[MVP] - */ - write_vpe_c0_vpeconf0( - read_vpe_c0_vpeconf0() | - VPECONF0_MVP); - } - cpu++; - } - printk(" %d", tc); - tc++; - } - if (vpe != 0) { - /* - * Allow this VPE to control others. - */ - write_vpe_c0_vpeconf0(read_vpe_c0_vpeconf0() | - VPECONF0_MVP); - - /* - * Clear any stale software interrupts from VPE's Cause - */ - write_vpe_c0_cause(0); - - /* - * Clear ERL/EXL of VPEs other than 0 - * and set restricted interrupt enable/mask. - */ - write_vpe_c0_status((read_vpe_c0_status() - & ~(ST0_BEV | ST0_ERL | ST0_EXL | ST0_IM)) - | (STATUSF_IP0 | STATUSF_IP1 | STATUSF_IP7 - | ST0_IE)); - /* - * set config to be the same as vpe0, - * particularly kseg0 coherency alg - */ - write_vpe_c0_config(read_c0_config()); - /* Clear any pending timer interrupt */ - write_vpe_c0_compare(0); - /* Propagate Config7 */ - write_vpe_c0_config7(read_c0_config7()); - write_vpe_c0_count(read_c0_count() + CP0_SKEW); - ehb(); - } - /* enable multi-threading within VPE */ - write_vpe_c0_vpecontrol(read_vpe_c0_vpecontrol() | VPECONTROL_TE); - /* enable the VPE */ - write_vpe_c0_vpeconf0(read_vpe_c0_vpeconf0() | VPECONF0_VPA); - } - - /* - * Pull any physically present but unused TCs out of circulation. - */ - while (tc < (((val & MVPCONF0_PTC) >> MVPCONF0_PTC_SHIFT) + 1)) { - set_cpu_possible(tc, false); - set_cpu_present(tc, false); - tc++; - } - - /* release config state */ - write_c0_mvpcontrol( read_c0_mvpcontrol() & ~ MVPCONTROL_VPC ); - - printk("\n"); - - /* Set up coprocessor affinity CPU mask(s) */ - -#ifdef CONFIG_MIPS_MT_FPAFF - for (tc = 0; tc < ntc; tc++) { - if (cpu_data[tc].options & MIPS_CPU_FPU) - cpu_set(tc, mt_fpu_cpumask); - } -#endif - - /* set up ipi interrupts... */ - - /* If we have multiple VPEs running, set up the cross-VPE interrupt */ - - setup_cross_vpe_interrupts(nvpe); - - /* Set up queue of free IPI "messages". */ - nipi = NR_CPUS * IPIBUF_PER_CPU; - if (ipibuffers > 0) - nipi = ipibuffers; - - pipi = kmalloc(nipi *sizeof(struct smtc_ipi), GFP_KERNEL); - if (pipi == NULL) - panic("kmalloc of IPI message buffers failed"); - else - printk("IPI buffer pool of %d buffers\n", nipi); - for (i = 0; i < nipi; i++) { - smtc_ipi_nq(&freeIPIq, pipi); - pipi++; - } - - /* Arm multithreading and enable other VPEs - but all TCs are Halted */ - emt(EMT_ENABLE); - evpe(EVPE_ENABLE); - local_irq_restore(flags); - /* Initialize SMTC /proc statistics/diagnostics */ - init_smtc_stats(); -} - - -/* - * Setup the PC, SP, and GP of a secondary processor and start it - * running! - * smp_bootstrap is the place to resume from - * __KSTK_TOS(idle) is apparently the stack pointer - * (unsigned long)idle->thread_info the gp - * - */ -void smtc_boot_secondary(int cpu, struct task_struct *idle) -{ - extern u32 kernelsp[NR_CPUS]; - unsigned long flags; - int mtflags; - - LOCK_MT_PRA(); - if (cpu_data[cpu].vpe_id != cpu_data[smp_processor_id()].vpe_id) { - dvpe(); - } - settc(cpu_data[cpu].tc_id); - - /* pc */ - write_tc_c0_tcrestart((unsigned long)&smp_bootstrap); - - /* stack pointer */ - kernelsp[cpu] = __KSTK_TOS(idle); - write_tc_gpr_sp(__KSTK_TOS(idle)); - - /* global pointer */ - write_tc_gpr_gp((unsigned long)task_thread_info(idle)); - - smtc_status |= SMTC_MTC_ACTIVE; - write_tc_c0_tchalt(0); - if (cpu_data[cpu].vpe_id != cpu_data[smp_processor_id()].vpe_id) { - evpe(EVPE_ENABLE); - } - UNLOCK_MT_PRA(); -} - -void smtc_init_secondary(void) -{ -} - -void smtc_smp_finish(void) -{ - int cpu = smp_processor_id(); - - /* - * Lowest-numbered CPU per VPE starts a clock tick. - * Like per_cpu_trap_init() hack, this assumes that - * SMTC init code assigns TCs consdecutively and - * in ascending order across available VPEs. - */ - if (cpu > 0 && (cpu_data[cpu].vpe_id != cpu_data[cpu - 1].vpe_id)) - write_c0_compare(read_c0_count() + mips_hpt_frequency/HZ); - - local_irq_enable(); - - printk("TC %d going on-line as CPU %d\n", - cpu_data[smp_processor_id()].tc_id, smp_processor_id()); -} - -void smtc_cpus_done(void) -{ -} - -/* - * Support for SMTC-optimized driver IRQ registration - */ - -/* - * SMTC Kernel needs to manipulate low-level CPU interrupt mask - * in do_IRQ. These are passed in setup_irq_smtc() and stored - * in this table. - */ - -int setup_irq_smtc(unsigned int irq, struct irqaction * new, - unsigned long hwmask) -{ -#ifdef CONFIG_SMTC_IDLE_HOOK_DEBUG - unsigned int vpe = current_cpu_data.vpe_id; - - vpemask[vpe][irq - MIPS_CPU_IRQ_BASE] = 1; -#endif - irq_hwmask[irq] = hwmask; - - return setup_irq(irq, new); -} - -#ifdef CONFIG_MIPS_MT_SMTC_IRQAFF -/* - * Support for IRQ affinity to TCs - */ - -void smtc_set_irq_affinity(unsigned int irq, cpumask_t affinity) -{ - /* - * If a "fast path" cache of quickly decodable affinity state - * is maintained, this is where it gets done, on a call up - * from the platform affinity code. - */ -} - -void smtc_forward_irq(struct irq_data *d) -{ - unsigned int irq = d->irq; - int target; - - /* - * OK wise guy, now figure out how to get the IRQ - * to be serviced on an authorized "CPU". - * - * Ideally, to handle the situation where an IRQ has multiple - * eligible CPUS, we would maintain state per IRQ that would - * allow a fair distribution of service requests. Since the - * expected use model is any-or-only-one, for simplicity - * and efficiency, we just pick the easiest one to find. - */ - - target = cpumask_first(d->affinity); - - /* - * We depend on the platform code to have correctly processed - * IRQ affinity change requests to ensure that the IRQ affinity - * mask has been purged of bits corresponding to nonexistent and - * offline "CPUs", and to TCs bound to VPEs other than the VPE - * connected to the physical interrupt input for the interrupt - * in question. Otherwise we have a nasty problem with interrupt - * mask management. This is best handled in non-performance-critical - * platform IRQ affinity setting code, to minimize interrupt-time - * checks. - */ - - /* If no one is eligible, service locally */ - if (target >= NR_CPUS) - do_IRQ_no_affinity(irq); - else - smtc_send_ipi(target, IRQ_AFFINITY_IPI, irq); -} - -#endif /* CONFIG_MIPS_MT_SMTC_IRQAFF */ - -/* - * IPI model for SMTC is tricky, because interrupts aren't TC-specific. - * Within a VPE one TC can interrupt another by different approaches. - * The easiest to get right would probably be to make all TCs except - * the target IXMT and set a software interrupt, but an IXMT-based - * scheme requires that a handler must run before a new IPI could - * be sent, which would break the "broadcast" loops in MIPS MT. - * A more gonzo approach within a VPE is to halt the TC, extract - * its Restart, Status, and a couple of GPRs, and program the Restart - * address to emulate an interrupt. - * - * Within a VPE, one can be confident that the target TC isn't in - * a critical EXL state when halted, since the write to the Halt - * register could not have issued on the writing thread if the - * halting thread had EXL set. So k0 and k1 of the target TC - * can be used by the injection code. Across VPEs, one can't - * be certain that the target TC isn't in a critical exception - * state. So we try a two-step process of sending a software - * interrupt to the target VPE, which either handles the event - * itself (if it was the target) or injects the event within - * the VPE. - */ - -static void smtc_ipi_qdump(void) -{ - int i; - struct smtc_ipi *temp; - - for (i = 0; i < NR_CPUS ;i++) { - pr_info("IPIQ[%d]: head = 0x%x, tail = 0x%x, depth = %d\n", - i, (unsigned)IPIQ[i].head, (unsigned)IPIQ[i].tail, - IPIQ[i].depth); - temp = IPIQ[i].head; - - while (temp != IPIQ[i].tail) { - pr_debug("%d %d %d: ", temp->type, temp->dest, - (int)temp->arg); -#ifdef SMTC_IPI_DEBUG - pr_debug("%u %lu\n", temp->sender, temp->stamp); -#else - pr_debug("\n"); -#endif - temp = temp->flink; - } - } -} - -/* - * The standard atomic.h primitives don't quite do what we want - * here: We need an atomic add-and-return-previous-value (which - * could be done with atomic_add_return and a decrement) and an - * atomic set/zero-and-return-previous-value (which can't really - * be done with the atomic.h primitives). And since this is - * MIPS MT, we can assume that we have LL/SC. - */ -static inline int atomic_postincrement(atomic_t *v) -{ - unsigned long result; - - unsigned long temp; - - __asm__ __volatile__( - "1: ll %0, %2 \n" - " addu %1, %0, 1 \n" - " sc %1, %2 \n" - " beqz %1, 1b \n" - __WEAK_LLSC_MB - : "=&r" (result), "=&r" (temp), "=m" (v->counter) - : "m" (v->counter) - : "memory"); - - return result; -} - -void smtc_send_ipi(int cpu, int type, unsigned int action) -{ - int tcstatus; - struct smtc_ipi *pipi; - unsigned long flags; - int mtflags; - unsigned long tcrestart; - int set_resched_flag = (type == LINUX_SMP_IPI && - action == SMP_RESCHEDULE_YOURSELF); - - if (cpu == smp_processor_id()) { - printk("Cannot Send IPI to self!\n"); - return; - } - if (set_resched_flag && IPIQ[cpu].resched_flag != 0) - return; /* There is a reschedule queued already */ - - /* Set up a descriptor, to be delivered either promptly or queued */ - pipi = smtc_ipi_dq(&freeIPIq); - if (pipi == NULL) { - bust_spinlocks(1); - mips_mt_regdump(dvpe()); - panic("IPI Msg. Buffers Depleted"); - } - pipi->type = type; - pipi->arg = (void *)action; - pipi->dest = cpu; - if (cpu_data[cpu].vpe_id != cpu_data[smp_processor_id()].vpe_id) { - /* If not on same VPE, enqueue and send cross-VPE interrupt */ - IPIQ[cpu].resched_flag |= set_resched_flag; - smtc_ipi_nq(&IPIQ[cpu], pipi); - LOCK_CORE_PRA(); - settc(cpu_data[cpu].tc_id); - write_vpe_c0_cause(read_vpe_c0_cause() | C_SW1); - UNLOCK_CORE_PRA(); - } else { - /* - * Not sufficient to do a LOCK_MT_PRA (dmt) here, - * since ASID shootdown on the other VPE may - * collide with this operation. - */ - LOCK_CORE_PRA(); - settc(cpu_data[cpu].tc_id); - /* Halt the targeted TC */ - write_tc_c0_tchalt(TCHALT_H); - mips_ihb(); - - /* - * Inspect TCStatus - if IXMT is set, we have to queue - * a message. Otherwise, we set up the "interrupt" - * of the other TC - */ - tcstatus = read_tc_c0_tcstatus(); - - if ((tcstatus & TCSTATUS_IXMT) != 0) { - /* - * If we're in the the irq-off version of the wait - * loop, we need to force exit from the wait and - * do a direct post of the IPI. - */ - if (cpu_wait == r4k_wait_irqoff) { - tcrestart = read_tc_c0_tcrestart(); - if (address_is_in_r4k_wait_irqoff(tcrestart)) { - write_tc_c0_tcrestart(__pastwait); - tcstatus &= ~TCSTATUS_IXMT; - write_tc_c0_tcstatus(tcstatus); - goto postdirect; - } - } - /* - * Otherwise we queue the message for the target TC - * to pick up when he does a local_irq_restore() - */ - write_tc_c0_tchalt(0); - UNLOCK_CORE_PRA(); - IPIQ[cpu].resched_flag |= set_resched_flag; - smtc_ipi_nq(&IPIQ[cpu], pipi); - } else { -postdirect: - post_direct_ipi(cpu, pipi); - write_tc_c0_tchalt(0); - UNLOCK_CORE_PRA(); - } - } -} - -/* - * Send IPI message to Halted TC, TargTC/TargVPE already having been set - */ -static void post_direct_ipi(int cpu, struct smtc_ipi *pipi) -{ - struct pt_regs *kstack; - unsigned long tcstatus; - unsigned long tcrestart; - extern u32 kernelsp[NR_CPUS]; - extern void __smtc_ipi_vector(void); -//printk("%s: on %d for %d\n", __func__, smp_processor_id(), cpu); - - /* Extract Status, EPC from halted TC */ - tcstatus = read_tc_c0_tcstatus(); - tcrestart = read_tc_c0_tcrestart(); - /* If TCRestart indicates a WAIT instruction, advance the PC */ - if ((tcrestart & 0x80000000) - && ((*(unsigned int *)tcrestart & 0xfe00003f) == 0x42000020)) { - tcrestart += 4; - } - /* - * Save on TC's future kernel stack - * - * CU bit of Status is indicator that TC was - * already running on a kernel stack... - */ - if (tcstatus & ST0_CU0) { - /* Note that this "- 1" is pointer arithmetic */ - kstack = ((struct pt_regs *)read_tc_gpr_sp()) - 1; - } else { - kstack = ((struct pt_regs *)kernelsp[cpu]) - 1; - } - - kstack->cp0_epc = (long)tcrestart; - /* Save TCStatus */ - kstack->cp0_tcstatus = tcstatus; - /* Pass token of operation to be performed kernel stack pad area */ - kstack->pad0[4] = (unsigned long)pipi; - /* Pass address of function to be called likewise */ - kstack->pad0[5] = (unsigned long)&ipi_decode; - /* Set interrupt exempt and kernel mode */ - tcstatus |= TCSTATUS_IXMT; - tcstatus &= ~TCSTATUS_TKSU; - write_tc_c0_tcstatus(tcstatus); - ehb(); - /* Set TC Restart address to be SMTC IPI vector */ - write_tc_c0_tcrestart(__smtc_ipi_vector); -} - -static void ipi_resched_interrupt(void) -{ - scheduler_ipi(); -} - -static void ipi_call_interrupt(void) -{ - /* Invoke generic function invocation code in smp.c */ - smp_call_function_interrupt(); -} - -DECLARE_PER_CPU(struct clock_event_device, mips_clockevent_device); - -static void __irq_entry smtc_clock_tick_interrupt(void) -{ - unsigned int cpu = smp_processor_id(); - struct clock_event_device *cd; - int irq = MIPS_CPU_IRQ_BASE + 1; - - irq_enter(); - kstat_incr_irq_this_cpu(irq); - cd = &per_cpu(mips_clockevent_device, cpu); - cd->event_handler(cd); - irq_exit(); -} - -void ipi_decode(struct smtc_ipi *pipi) -{ - void *arg_copy = pipi->arg; - int type_copy = pipi->type; - - smtc_ipi_nq(&freeIPIq, pipi); - - switch (type_copy) { - case SMTC_CLOCK_TICK: - smtc_clock_tick_interrupt(); - break; - - case LINUX_SMP_IPI: - switch ((int)arg_copy) { - case SMP_RESCHEDULE_YOURSELF: - ipi_resched_interrupt(); - break; - case SMP_CALL_FUNCTION: - ipi_call_interrupt(); - break; - default: - printk("Impossible SMTC IPI Argument %p\n", arg_copy); - break; - } - break; -#ifdef CONFIG_MIPS_MT_SMTC_IRQAFF - case IRQ_AFFINITY_IPI: - /* - * Accept a "forwarded" interrupt that was initially - * taken by a TC who doesn't have affinity for the IRQ. - */ - do_IRQ_no_affinity((int)arg_copy); - break; -#endif /* CONFIG_MIPS_MT_SMTC_IRQAFF */ - default: - printk("Impossible SMTC IPI Type 0x%x\n", type_copy); - break; - } -} - -/* - * Similar to smtc_ipi_replay(), but invoked from context restore, - * so it reuses the current exception frame rather than set up a - * new one with self_ipi. - */ - -void deferred_smtc_ipi(void) -{ - int cpu = smp_processor_id(); - - /* - * Test is not atomic, but much faster than a dequeue, - * and the vast majority of invocations will have a null queue. - * If irq_disabled when this was called, then any IPIs queued - * after we test last will be taken on the next irq_enable/restore. - * If interrupts were enabled, then any IPIs added after the - * last test will be taken directly. - */ - - while (IPIQ[cpu].head != NULL) { - struct smtc_ipi_q *q = &IPIQ[cpu]; - struct smtc_ipi *pipi; - unsigned long flags; - - /* - * It may be possible we'll come in with interrupts - * already enabled. - */ - local_irq_save(flags); - spin_lock(&q->lock); - pipi = __smtc_ipi_dq(q); - spin_unlock(&q->lock); - if (pipi != NULL) { - if (pipi->type == LINUX_SMP_IPI && - (int)pipi->arg == SMP_RESCHEDULE_YOURSELF) - IPIQ[cpu].resched_flag = 0; - ipi_decode(pipi); - } - /* - * The use of the __raw_local restore isn't - * as obviously necessary here as in smtc_ipi_replay(), - * but it's more efficient, given that we're already - * running down the IPI queue. - */ - __arch_local_irq_restore(flags); - } -} - -/* - * Cross-VPE interrupts in the SMTC prototype use "software interrupts" - * set via cross-VPE MTTR manipulation of the Cause register. It would be - * in some regards preferable to have external logic for "doorbell" hardware - * interrupts. - */ - -static int cpu_ipi_irq = MIPS_CPU_IRQ_BASE + MIPS_CPU_IPI_IRQ; - -static irqreturn_t ipi_interrupt(int irq, void *dev_idm) -{ - int my_vpe = cpu_data[smp_processor_id()].vpe_id; - int my_tc = cpu_data[smp_processor_id()].tc_id; - int cpu; - struct smtc_ipi *pipi; - unsigned long tcstatus; - int sent; - unsigned long flags; - unsigned int mtflags; - unsigned int vpflags; - - /* - * So long as cross-VPE interrupts are done via - * MFTR/MTTR read-modify-writes of Cause, we need - * to stop other VPEs whenever the local VPE does - * anything similar. - */ - local_irq_save(flags); - vpflags = dvpe(); - clear_c0_cause(0x100 << MIPS_CPU_IPI_IRQ); - set_c0_status(0x100 << MIPS_CPU_IPI_IRQ); - irq_enable_hazard(); - evpe(vpflags); - local_irq_restore(flags); - - /* - * Cross-VPE Interrupt handler: Try to directly deliver IPIs - * queued for TCs on this VPE other than the current one. - * Return-from-interrupt should cause us to drain the queue - * for the current TC, so we ought not to have to do it explicitly here. - */ - - for_each_online_cpu(cpu) { - if (cpu_data[cpu].vpe_id != my_vpe) - continue; - - pipi = smtc_ipi_dq(&IPIQ[cpu]); - if (pipi != NULL) { - if (cpu_data[cpu].tc_id != my_tc) { - sent = 0; - LOCK_MT_PRA(); - settc(cpu_data[cpu].tc_id); - write_tc_c0_tchalt(TCHALT_H); - mips_ihb(); - tcstatus = read_tc_c0_tcstatus(); - if ((tcstatus & TCSTATUS_IXMT) == 0) { - post_direct_ipi(cpu, pipi); - sent = 1; - } - write_tc_c0_tchalt(0); - UNLOCK_MT_PRA(); - if (!sent) { - smtc_ipi_req(&IPIQ[cpu], pipi); - } - } else { - /* - * ipi_decode() should be called - * with interrupts off - */ - local_irq_save(flags); - if (pipi->type == LINUX_SMP_IPI && - (int)pipi->arg == SMP_RESCHEDULE_YOURSELF) - IPIQ[cpu].resched_flag = 0; - ipi_decode(pipi); - local_irq_restore(flags); - } - } - } - - return IRQ_HANDLED; -} - -static void ipi_irq_dispatch(void) -{ - do_IRQ(cpu_ipi_irq); -} - -static struct irqaction irq_ipi = { - .handler = ipi_interrupt, - .flags = IRQF_PERCPU, - .name = "SMTC_IPI" -}; - -static void setup_cross_vpe_interrupts(unsigned int nvpe) -{ - if (nvpe < 1) - return; - - if (!cpu_has_vint) - panic("SMTC Kernel requires Vectored Interrupt support"); - - set_vi_handler(MIPS_CPU_IPI_IRQ, ipi_irq_dispatch); - - setup_irq_smtc(cpu_ipi_irq, &irq_ipi, (0x100 << MIPS_CPU_IPI_IRQ)); - - irq_set_handler(cpu_ipi_irq, handle_percpu_irq); -} - -/* - * SMTC-specific hacks invoked from elsewhere in the kernel. - */ - - /* - * smtc_ipi_replay is called from raw_local_irq_restore - */ - -void smtc_ipi_replay(void) -{ - unsigned int cpu = smp_processor_id(); - - /* - * To the extent that we've ever turned interrupts off, - * we may have accumulated deferred IPIs. This is subtle. - * we should be OK: If we pick up something and dispatch - * it here, that's great. If we see nothing, but concurrent - * with this operation, another TC sends us an IPI, IXMT - * is clear, and we'll handle it as a real pseudo-interrupt - * and not a pseudo-pseudo interrupt. The important thing - * is to do the last check for queued message *after* the - * re-enabling of interrupts. - */ - while (IPIQ[cpu].head != NULL) { - struct smtc_ipi_q *q = &IPIQ[cpu]; - struct smtc_ipi *pipi; - unsigned long flags; - - /* - * It's just possible we'll come in with interrupts - * already enabled. - */ - local_irq_save(flags); - - spin_lock(&q->lock); - pipi = __smtc_ipi_dq(q); - spin_unlock(&q->lock); - /* - ** But use a raw restore here to avoid recursion. - */ - __arch_local_irq_restore(flags); - - if (pipi) { - self_ipi(pipi); - smtc_cpu_stats[cpu].selfipis++; - } - } -} - -EXPORT_SYMBOL(smtc_ipi_replay); - -void smtc_idle_loop_hook(void) -{ -#ifdef CONFIG_SMTC_IDLE_HOOK_DEBUG - int im; - int flags; - int mtflags; - int bit; - int vpe; - int tc; - int hook_ntcs; - /* - * printk within DMT-protected regions can deadlock, - * so buffer diagnostic messages for later output. - */ - char *pdb_msg; - char id_ho_db_msg[768]; /* worst-case use should be less than 700 */ - - if (atomic_read(&idle_hook_initialized) == 0) { /* fast test */ - if (atomic_add_return(1, &idle_hook_initialized) == 1) { - int mvpconf0; - /* Tedious stuff to just do once */ - mvpconf0 = read_c0_mvpconf0(); - hook_ntcs = ((mvpconf0 & MVPCONF0_PTC) >> MVPCONF0_PTC_SHIFT) + 1; - if (hook_ntcs > NR_CPUS) - hook_ntcs = NR_CPUS; - for (tc = 0; tc < hook_ntcs; tc++) { - tcnoprog[tc] = 0; - clock_hang_reported[tc] = 0; - } - for (vpe = 0; vpe < 2; vpe++) - for (im = 0; im < 8; im++) - imstuckcount[vpe][im] = 0; - printk("Idle loop test hook initialized for %d TCs\n", hook_ntcs); - atomic_set(&idle_hook_initialized, 1000); - } else { - /* Someone else is initializing in parallel - let 'em finish */ - while (atomic_read(&idle_hook_initialized) < 1000) - ; - } - } - - /* Have we stupidly left IXMT set somewhere? */ - if (read_c0_tcstatus() & 0x400) { - write_c0_tcstatus(read_c0_tcstatus() & ~0x400); - ehb(); - printk("Dangling IXMT in cpu_idle()\n"); - } - - /* Have we stupidly left an IM bit turned off? */ -#define IM_LIMIT 2000 - local_irq_save(flags); - mtflags = dmt(); - pdb_msg = &id_ho_db_msg[0]; - im = read_c0_status(); - vpe = current_cpu_data.vpe_id; - for (bit = 0; bit < 8; bit++) { - /* - * In current prototype, I/O interrupts - * are masked for VPE > 0 - */ - if (vpemask[vpe][bit]) { - if (!(im & (0x100 << bit))) - imstuckcount[vpe][bit]++; - else - imstuckcount[vpe][bit] = 0; - if (imstuckcount[vpe][bit] > IM_LIMIT) { - set_c0_status(0x100 << bit); - ehb(); - imstuckcount[vpe][bit] = 0; - pdb_msg += sprintf(pdb_msg, - "Dangling IM %d fixed for VPE %d\n", bit, - vpe); - } - } - } - - emt(mtflags); - local_irq_restore(flags); - if (pdb_msg != &id_ho_db_msg[0]) - printk("CPU%d: %s", smp_processor_id(), id_ho_db_msg); -#endif /* CONFIG_SMTC_IDLE_HOOK_DEBUG */ - - smtc_ipi_replay(); -} - -void smtc_soft_dump(void) -{ - int i; - - printk("Counter Interrupts taken per CPU (TC)\n"); - for (i=0; i < NR_CPUS; i++) { - printk("%d: %ld\n", i, smtc_cpu_stats[i].timerints); - } - printk("Self-IPI invocations:\n"); - for (i=0; i < NR_CPUS; i++) { - printk("%d: %ld\n", i, smtc_cpu_stats[i].selfipis); - } - smtc_ipi_qdump(); - printk("%d Recoveries of \"stolen\" FPU\n", - atomic_read(&smtc_fpu_recoveries)); -} - - -/* - * TLB management routines special to SMTC - */ - -void smtc_get_new_mmu_context(struct mm_struct *mm, unsigned long cpu) -{ - unsigned long flags, mtflags, tcstat, prevhalt, asid; - int tlb, i; - - /* - * It would be nice to be able to use a spinlock here, - * but this is invoked from within TLB flush routines - * that protect themselves with DVPE, so if a lock is - * held by another TC, it'll never be freed. - * - * DVPE/DMT must not be done with interrupts enabled, - * so even so most callers will already have disabled - * them, let's be really careful... - */ - - local_irq_save(flags); - if (smtc_status & SMTC_TLB_SHARED) { - mtflags = dvpe(); - tlb = 0; - } else { - mtflags = dmt(); - tlb = cpu_data[cpu].vpe_id; - } - asid = asid_cache(cpu); - - do { - if (!((asid += ASID_INC) & ASID_MASK) ) { - if (cpu_has_vtag_icache) - flush_icache_all(); - /* Traverse all online CPUs (hack requires contiguous range) */ - for_each_online_cpu(i) { - /* - * We don't need to worry about our own CPU, nor those of - * CPUs who don't share our TLB. - */ - if ((i != smp_processor_id()) && - ((smtc_status & SMTC_TLB_SHARED) || - (cpu_data[i].vpe_id == cpu_data[cpu].vpe_id))) { - settc(cpu_data[i].tc_id); - prevhalt = read_tc_c0_tchalt() & TCHALT_H; - if (!prevhalt) { - write_tc_c0_tchalt(TCHALT_H); - mips_ihb(); - } - tcstat = read_tc_c0_tcstatus(); - smtc_live_asid[tlb][(tcstat & ASID_MASK)] |= (asiduse)(0x1 << i); - if (!prevhalt) - write_tc_c0_tchalt(0); - } - } - if (!asid) /* fix version if needed */ - asid = ASID_FIRST_VERSION; - local_flush_tlb_all(); /* start new asid cycle */ - } - } while (smtc_live_asid[tlb][(asid & ASID_MASK)]); - - /* - * SMTC shares the TLB within VPEs and possibly across all VPEs. - */ - for_each_online_cpu(i) { - if ((smtc_status & SMTC_TLB_SHARED) || - (cpu_data[i].vpe_id == cpu_data[cpu].vpe_id)) - cpu_context(i, mm) = asid_cache(i) = asid; - } - - if (smtc_status & SMTC_TLB_SHARED) - evpe(mtflags); - else - emt(mtflags); - local_irq_restore(flags); -} - -/* - * Invoked from macros defined in mmu_context.h - * which must already have disabled interrupts - * and done a DVPE or DMT as appropriate. - */ - -void smtc_flush_tlb_asid(unsigned long asid) -{ - int entry; - unsigned long ehi; - - entry = read_c0_wired(); - - /* Traverse all non-wired entries */ - while (entry < current_cpu_data.tlbsize) { - write_c0_index(entry); - ehb(); - tlb_read(); - ehb(); - ehi = read_c0_entryhi(); - if ((ehi & ASID_MASK) == asid) { - /* - * Invalidate only entries with specified ASID, - * makiing sure all entries differ. - */ - write_c0_entryhi(CKSEG0 + (entry << (PAGE_SHIFT + 1))); - write_c0_entrylo0(0); - write_c0_entrylo1(0); - mtc0_tlbw_hazard(); - tlb_write_indexed(); - } - entry++; - } - write_c0_index(PARKED_INDEX); - tlbw_use_hazard(); -} - -/* - * Support for single-threading cache flush operations. - */ - -static int halt_state_save[NR_CPUS]; - -/* - * To really, really be sure that nothing is being done - * by other TCs, halt them all. This code assumes that - * a DVPE has already been done, so while their Halted - * state is theoretically architecturally unstable, in - * practice, it's not going to change while we're looking - * at it. - */ - -void smtc_cflush_lockdown(void) -{ - int cpu; - - for_each_online_cpu(cpu) { - if (cpu != smp_processor_id()) { - settc(cpu_data[cpu].tc_id); - halt_state_save[cpu] = read_tc_c0_tchalt(); - write_tc_c0_tchalt(TCHALT_H); - } - } - mips_ihb(); -} - -/* It would be cheating to change the cpu_online states during a flush! */ - -void smtc_cflush_release(void) -{ - int cpu; - - /* - * Start with a hazard barrier to ensure - * that all CACHE ops have played through. - */ - mips_ihb(); - - for_each_online_cpu(cpu) { - if (cpu != smp_processor_id()) { - settc(cpu_data[cpu].tc_id); - write_tc_c0_tchalt(halt_state_save[cpu]); - } - } - mips_ihb(); -} |