/*
* 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 struct task_struct *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;
struct task_struct *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;
struct task_struct *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 */
}
