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author | Ralf Baechle <ralf@linux-mips.org> | 2006-04-05 09:45:45 +0100 |
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committer | Ralf Baechle <ralf@linux-mips.org> | 2006-04-19 04:14:28 +0200 |
commit | 41c594ab65fc89573af296d192aa5235d09717ab (patch) | |
tree | 562462512a320f386bdf49eabfbb26bb3ee761fa /arch/mips/kernel/mips-mt.c | |
parent | 2600990e640e3bef29ed89d565864cf16ee83833 (diff) | |
download | blackbird-op-linux-41c594ab65fc89573af296d192aa5235d09717ab.tar.gz blackbird-op-linux-41c594ab65fc89573af296d192aa5235d09717ab.zip |
[MIPS] MT: Improved multithreading support.
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Diffstat (limited to 'arch/mips/kernel/mips-mt.c')
-rw-r--r-- | arch/mips/kernel/mips-mt.c | 449 |
1 files changed, 449 insertions, 0 deletions
diff --git a/arch/mips/kernel/mips-mt.c b/arch/mips/kernel/mips-mt.c new file mode 100644 index 000000000000..02237a685ec7 --- /dev/null +++ b/arch/mips/kernel/mips-mt.c @@ -0,0 +1,449 @@ +/* + * General MIPS MT support routines, usable in AP/SP, SMVP, or SMTC kernels + * Copyright (C) 2005 Mips Technologies, Inc + */ + +#include <linux/kernel.h> +#include <linux/sched.h> +#include <linux/cpumask.h> +#include <linux/interrupt.h> + +#include <asm/cpu.h> +#include <asm/processor.h> +#include <asm/atomic.h> +#include <asm/system.h> +#include <asm/hardirq.h> +#include <asm/mmu_context.h> +#include <asm/smp.h> +#include <asm/mipsmtregs.h> +#include <asm/r4kcache.h> +#include <asm/cacheflush.h> + +/* + * CPU mask used to set process affinity for MT VPEs/TCs with FPUs + */ + +cpumask_t mt_fpu_cpumask; + +#ifdef CONFIG_MIPS_MT_FPAFF + +#include <linux/cpu.h> +#include <linux/delay.h> +#include <asm/uaccess.h> + +unsigned long mt_fpemul_threshold = 0; + +/* + * Replacement functions for the sys_sched_setaffinity() and + * sys_sched_getaffinity() system calls, so that we can integrate + * FPU affinity with the user's requested processor affinity. + * This code is 98% identical with the sys_sched_setaffinity() + * and sys_sched_getaffinity() system calls, and should be + * updated when kernel/sched.c changes. + */ + +/* + * find_process_by_pid - find a process with a matching PID value. + * used in sys_sched_set/getaffinity() in kernel/sched.c, so + * cloned here. + */ +static inline task_t *find_process_by_pid(pid_t pid) +{ + return pid ? find_task_by_pid(pid) : current; +} + + +/* + * mipsmt_sys_sched_setaffinity - set the cpu affinity of a process + */ +asmlinkage long mipsmt_sys_sched_setaffinity(pid_t pid, unsigned int len, + unsigned long __user *user_mask_ptr) +{ + cpumask_t new_mask; + cpumask_t effective_mask; + int retval; + task_t *p; + + if (len < sizeof(new_mask)) + return -EINVAL; + + if (copy_from_user(&new_mask, user_mask_ptr, sizeof(new_mask))) + return -EFAULT; + + lock_cpu_hotplug(); + read_lock(&tasklist_lock); + + p = find_process_by_pid(pid); + if (!p) { + read_unlock(&tasklist_lock); + unlock_cpu_hotplug(); + return -ESRCH; + } + + /* + * It is not safe to call set_cpus_allowed with the + * tasklist_lock held. We will bump the task_struct's + * usage count and drop tasklist_lock before invoking + * set_cpus_allowed. + */ + get_task_struct(p); + + retval = -EPERM; + if ((current->euid != p->euid) && (current->euid != p->uid) && + !capable(CAP_SYS_NICE)) { + read_unlock(&tasklist_lock); + goto out_unlock; + } + + /* Record new user-specified CPU set for future reference */ + p->thread.user_cpus_allowed = new_mask; + + /* Unlock the task list */ + read_unlock(&tasklist_lock); + + /* Compute new global allowed CPU set if necessary */ + if( (p->thread.mflags & MF_FPUBOUND) + && cpus_intersects(new_mask, mt_fpu_cpumask)) { + cpus_and(effective_mask, new_mask, mt_fpu_cpumask); + retval = set_cpus_allowed(p, effective_mask); + } else { + p->thread.mflags &= ~MF_FPUBOUND; + retval = set_cpus_allowed(p, new_mask); + } + + +out_unlock: + put_task_struct(p); + unlock_cpu_hotplug(); + return retval; +} + +/* + * mipsmt_sys_sched_getaffinity - get the cpu affinity of a process + */ +asmlinkage long mipsmt_sys_sched_getaffinity(pid_t pid, unsigned int len, + unsigned long __user *user_mask_ptr) +{ + unsigned int real_len; + cpumask_t mask; + int retval; + task_t *p; + + real_len = sizeof(mask); + if (len < real_len) + return -EINVAL; + + lock_cpu_hotplug(); + read_lock(&tasklist_lock); + + retval = -ESRCH; + p = find_process_by_pid(pid); + if (!p) + goto out_unlock; + + retval = 0; + + cpus_and(mask, p->thread.user_cpus_allowed, cpu_possible_map); + +out_unlock: + read_unlock(&tasklist_lock); + unlock_cpu_hotplug(); + if (retval) + return retval; + if (copy_to_user(user_mask_ptr, &mask, real_len)) + return -EFAULT; + return real_len; +} + +#endif /* CONFIG_MIPS_MT_FPAFF */ + +/* + * Dump new MIPS MT state for the core. Does not leave TCs halted. + * Takes an argument which taken to be a pre-call MVPControl value. + */ + +void mips_mt_regdump(unsigned long mvpctl) +{ + unsigned long flags; + unsigned long vpflags; + unsigned long mvpconf0; + int nvpe; + int ntc; + int i; + int tc; + unsigned long haltval; + unsigned long tcstatval; +#ifdef CONFIG_MIPS_MT_SMTC + void smtc_soft_dump(void); +#endif /* CONFIG_MIPT_MT_SMTC */ + + local_irq_save(flags); + vpflags = dvpe(); + printk("=== MIPS MT State Dump ===\n"); + printk("-- Global State --\n"); + printk(" MVPControl Passed: %08lx\n", mvpctl); + printk(" MVPControl Read: %08lx\n", vpflags); + printk(" MVPConf0 : %08lx\n", (mvpconf0 = read_c0_mvpconf0())); + nvpe = ((mvpconf0 & MVPCONF0_PVPE) >> MVPCONF0_PVPE_SHIFT) + 1; + ntc = ((mvpconf0 & MVPCONF0_PTC) >> MVPCONF0_PTC_SHIFT) + 1; + printk("-- per-VPE State --\n"); + for(i = 0; i < nvpe; i++) { + for(tc = 0; tc < ntc; tc++) { + settc(tc); + if((read_tc_c0_tcbind() & TCBIND_CURVPE) == i) { + printk(" VPE %d\n", i); + printk(" VPEControl : %08lx\n", read_vpe_c0_vpecontrol()); + printk(" VPEConf0 : %08lx\n", read_vpe_c0_vpeconf0()); + printk(" VPE%d.Status : %08lx\n", + i, read_vpe_c0_status()); + printk(" VPE%d.EPC : %08lx\n", i, read_vpe_c0_epc()); + printk(" VPE%d.Cause : %08lx\n", i, read_vpe_c0_cause()); + printk(" VPE%d.Config7 : %08lx\n", + i, read_vpe_c0_config7()); + break; /* Next VPE */ + } + } + } + printk("-- per-TC State --\n"); + for(tc = 0; tc < ntc; tc++) { + settc(tc); + if(read_tc_c0_tcbind() == read_c0_tcbind()) { + /* Are we dumping ourself? */ + haltval = 0; /* Then we're not halted, and mustn't be */ + tcstatval = flags; /* And pre-dump TCStatus is flags */ + printk(" TC %d (current TC with VPE EPC above)\n", tc); + } else { + haltval = read_tc_c0_tchalt(); + write_tc_c0_tchalt(1); + tcstatval = read_tc_c0_tcstatus(); + printk(" TC %d\n", tc); + } + printk(" TCStatus : %08lx\n", tcstatval); + printk(" TCBind : %08lx\n", read_tc_c0_tcbind()); + printk(" TCRestart : %08lx\n", read_tc_c0_tcrestart()); + printk(" TCHalt : %08lx\n", haltval); + printk(" TCContext : %08lx\n", read_tc_c0_tccontext()); + if (!haltval) + write_tc_c0_tchalt(0); + } +#ifdef CONFIG_MIPS_MT_SMTC + smtc_soft_dump(); +#endif /* CONFIG_MIPT_MT_SMTC */ + printk("===========================\n"); + evpe(vpflags); + local_irq_restore(flags); +} + +static int mt_opt_norps = 0; +static int mt_opt_rpsctl = -1; +static int mt_opt_nblsu = -1; +static int mt_opt_forceconfig7 = 0; +static int mt_opt_config7 = -1; + +static int __init rps_disable(char *s) +{ + mt_opt_norps = 1; + return 1; +} +__setup("norps", rps_disable); + +static int __init rpsctl_set(char *str) +{ + get_option(&str, &mt_opt_rpsctl); + return 1; +} +__setup("rpsctl=", rpsctl_set); + +static int __init nblsu_set(char *str) +{ + get_option(&str, &mt_opt_nblsu); + return 1; +} +__setup("nblsu=", nblsu_set); + +static int __init config7_set(char *str) +{ + get_option(&str, &mt_opt_config7); + mt_opt_forceconfig7 = 1; + return 1; +} +__setup("config7=", config7_set); + +/* Experimental cache flush control parameters that should go away some day */ +int mt_protiflush = 0; +int mt_protdflush = 0; +int mt_n_iflushes = 1; +int mt_n_dflushes = 1; + +static int __init set_protiflush(char *s) +{ + mt_protiflush = 1; + return 1; +} +__setup("protiflush", set_protiflush); + +static int __init set_protdflush(char *s) +{ + mt_protdflush = 1; + return 1; +} +__setup("protdflush", set_protdflush); + +static int __init niflush(char *s) +{ + get_option(&s, &mt_n_iflushes); + return 1; +} +__setup("niflush=", niflush); + +static int __init ndflush(char *s) +{ + get_option(&s, &mt_n_dflushes); + return 1; +} +__setup("ndflush=", ndflush); +#ifdef CONFIG_MIPS_MT_FPAFF +static int fpaff_threshold = -1; + +static int __init fpaff_thresh(char *str) +{ + get_option(&str, &fpaff_threshold); + return 1; +} + +__setup("fpaff=", fpaff_thresh); +#endif /* CONFIG_MIPS_MT_FPAFF */ + +static unsigned int itc_base = 0; + +static int __init set_itc_base(char *str) +{ + get_option(&str, &itc_base); + return 1; +} + +__setup("itcbase=", set_itc_base); + +void mips_mt_set_cpuoptions(void) +{ + unsigned int oconfig7 = read_c0_config7(); + unsigned int nconfig7 = oconfig7; + + if (mt_opt_norps) { + printk("\"norps\" option deprectated: use \"rpsctl=\"\n"); + } + if (mt_opt_rpsctl >= 0) { + printk("34K return prediction stack override set to %d.\n", + mt_opt_rpsctl); + if (mt_opt_rpsctl) + nconfig7 |= (1 << 2); + else + nconfig7 &= ~(1 << 2); + } + if (mt_opt_nblsu >= 0) { + printk("34K ALU/LSU sync override set to %d.\n", mt_opt_nblsu); + if (mt_opt_nblsu) + nconfig7 |= (1 << 5); + else + nconfig7 &= ~(1 << 5); + } + if (mt_opt_forceconfig7) { + printk("CP0.Config7 forced to 0x%08x.\n", mt_opt_config7); + nconfig7 = mt_opt_config7; + } + if (oconfig7 != nconfig7) { + __asm__ __volatile("sync"); + write_c0_config7(nconfig7); + ehb (); + printk("Config7: 0x%08x\n", read_c0_config7()); + } + + /* Report Cache management debug options */ + if (mt_protiflush) + printk("I-cache flushes single-threaded\n"); + if (mt_protdflush) + printk("D-cache flushes single-threaded\n"); + if (mt_n_iflushes != 1) + printk("I-Cache Flushes Repeated %d times\n", mt_n_iflushes); + if (mt_n_dflushes != 1) + printk("D-Cache Flushes Repeated %d times\n", mt_n_dflushes); + +#ifdef CONFIG_MIPS_MT_FPAFF + /* FPU Use Factor empirically derived from experiments on 34K */ +#define FPUSEFACTOR 333 + + if (fpaff_threshold >= 0) { + mt_fpemul_threshold = fpaff_threshold; + } else { + mt_fpemul_threshold = + (FPUSEFACTOR * (loops_per_jiffy/(500000/HZ))) / HZ; + } + printk("FPU Affinity set after %ld emulations\n", + mt_fpemul_threshold); +#endif /* CONFIG_MIPS_MT_FPAFF */ + + if (itc_base != 0) { + /* + * Configure ITC mapping. This code is very + * specific to the 34K core family, which uses + * a special mode bit ("ITC") in the ErrCtl + * register to enable access to ITC control + * registers via cache "tag" operations. + */ + unsigned long ectlval; + unsigned long itcblkgrn; + + /* ErrCtl register is known as "ecc" to Linux */ + ectlval = read_c0_ecc(); + write_c0_ecc(ectlval | (0x1 << 26)); + ehb(); +#define INDEX_0 (0x80000000) +#define INDEX_8 (0x80000008) + /* Read "cache tag" for Dcache pseudo-index 8 */ + cache_op(Index_Load_Tag_D, INDEX_8); + ehb(); + itcblkgrn = read_c0_dtaglo(); + itcblkgrn &= 0xfffe0000; + /* Set for 128 byte pitch of ITC cells */ + itcblkgrn |= 0x00000c00; + /* Stage in Tag register */ + write_c0_dtaglo(itcblkgrn); + ehb(); + /* Write out to ITU with CACHE op */ + cache_op(Index_Store_Tag_D, INDEX_8); + /* Now set base address, and turn ITC on with 0x1 bit */ + write_c0_dtaglo((itc_base & 0xfffffc00) | 0x1 ); + ehb(); + /* Write out to ITU with CACHE op */ + cache_op(Index_Store_Tag_D, INDEX_0); + write_c0_ecc(ectlval); + ehb(); + printk("Mapped %ld ITC cells starting at 0x%08x\n", + ((itcblkgrn & 0x7fe00000) >> 20), itc_base); + } +} + +/* + * Function to protect cache flushes from concurrent execution + * depends on MP software model chosen. + */ + +void mt_cflush_lockdown(void) +{ +#ifdef CONFIG_MIPS_MT_SMTC + void smtc_cflush_lockdown(void); + + smtc_cflush_lockdown(); +#endif /* CONFIG_MIPS_MT_SMTC */ + /* FILL IN VSMP and AP/SP VERSIONS HERE */ +} + +void mt_cflush_release(void) +{ +#ifdef CONFIG_MIPS_MT_SMTC + void smtc_cflush_release(void); + + smtc_cflush_release(); +#endif /* CONFIG_MIPS_MT_SMTC */ + /* FILL IN VSMP and AP/SP VERSIONS HERE */ +} |