smp-mt.c
/*
* This program is free software; you can distribute it and/or modify it
* under the terms of the GNU General Public License (Version 2) as
* published by the Free Software Foundation.
*
* This program is distributed in the hope 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, 05, 06 MIPS Technologies, Inc.
* Elizabeth Clarke (beth@mips.com)
* Ralf Baechle (ralf@linux-mips.org)
* Copyright (C) 2006 Ralf Baechle (ralf@linux-mips.org)
*/
#include <linux/kernel.h>
#include <linux/sched.h>
#include <linux/cpumask.h>
#include <linux/interrupt.h>
#include <linux/compiler.h>
#include <linux/smp.h>
#include <asm/atomic.h>
#include <asm/cacheflush.h>
#include <asm/cpu.h>
#include <asm/processor.h>
#include <asm/system.h>
#include <asm/hardirq.h>
#include <asm/mmu_context.h>
#include <asm/time.h>
#include <asm/mipsregs.h>
#include <asm/mipsmtregs.h>
#include <asm/mips_mt.h>
static void __init smvp_copy_vpe_config(void)
{
write_vpe_c0_status(
(read_c0_status() & ~(ST0_IM | ST0_IE | ST0_KSU)) | ST0_CU0);
/* set config to be the same as vpe0, particularly kseg0 coherency alg */
write_vpe_c0_config( read_c0_config());
/* make sure there are no software interrupts pending */
write_vpe_c0_cause(0);
/* Propagate Config7 */
write_vpe_c0_config7(read_c0_config7());
write_vpe_c0_count(read_c0_count());
}
static unsigned int __init smvp_vpe_init(unsigned int tc, unsigned int mvpconf0,
unsigned int ncpu)
{
if (tc > ((mvpconf0 & MVPCONF0_PVPE) >> MVPCONF0_PVPE_SHIFT))
return ncpu;
/* Deactivate all but VPE 0 */
if (tc != 0) {
unsigned long tmp = read_vpe_c0_vpeconf0();
tmp &= ~VPECONF0_VPA;
/* master VPE */
tmp |= VPECONF0_MVP;
write_vpe_c0_vpeconf0(tmp);
/* Record this as available CPU */
set_cpu_possible(tc, true);
__cpu_number_map[tc] = ++ncpu;
__cpu_logical_map[ncpu] = tc;
}
/* Disable multi-threading with TC's */
write_vpe_c0_vpecontrol(read_vpe_c0_vpecontrol() & ~VPECONTROL_TE);
if (tc != 0)
smvp_copy_vpe_config();
return ncpu;
}
static void __init smvp_tc_init(unsigned int tc, unsigned int mvpconf0)
{
unsigned long tmp;
if (!tc)
return;
/* bind a TC to each VPE, May as well put all excess TC's
on the last VPE */
if (tc >= (((mvpconf0 & MVPCONF0_PVPE) >> MVPCONF0_PVPE_SHIFT)+1))
write_tc_c0_tcbind(read_tc_c0_tcbind() | ((mvpconf0 & MVPCONF0_PVPE) >> MVPCONF0_PVPE_SHIFT));
else {
write_tc_c0_tcbind(read_tc_c0_tcbind() | tc);
/* and set XTC */
write_vpe_c0_vpeconf0(read_vpe_c0_vpeconf0() | (tc << VPECONF0_XTC_SHIFT));
}
tmp = read_tc_c0_tcstatus();
/* mark not allocated and not dynamically allocatable */
tmp &= ~(TCSTATUS_A | TCSTATUS_DA);
tmp |= TCSTATUS_IXMT; /* interrupt exempt */
write_tc_c0_tcstatus(tmp);
write_tc_c0_tchalt(TCHALT_H);
}
static void vsmp_send_ipi_single(int cpu, unsigned int action)
{
int i;
unsigned long flags;
int vpflags;
local_irq_save(flags);
vpflags = dvpe(); /* cant access the other CPU's registers whilst MVPE enabled */
switch (action) {
case SMP_CALL_FUNCTION:
i = C_SW1;
break;
case SMP_RESCHEDULE_YOURSELF:
default:
i = C_SW0;
break;
}
/* 1:1 mapping of vpe and tc... */
settc(cpu);
write_vpe_c0_cause(read_vpe_c0_cause() | i);
evpe(vpflags);
local_irq_restore(flags);
}
static void vsmp_send_ipi_mask(const struct cpumask *mask, unsigned int action)
{
unsigned int i;
for_each_cpu(i, mask)
vsmp_send_ipi_single(i, action);
}
static void __cpuinit vsmp_init_secondary(void)
{
extern int gic_present;
/* This is Malta specific: IPI,performance and timer inetrrupts */
if (gic_present)
change_c0_status(ST0_IM, STATUSF_IP3 | STATUSF_IP4 |
STATUSF_IP6 | STATUSF_IP7);
else
change_c0_status(ST0_IM, STATUSF_IP0 | STATUSF_IP1 |
STATUSF_IP6 | STATUSF_IP7);
}
static void __cpuinit vsmp_smp_finish(void)
{
/* CDFIXME: remove this? */
write_c0_compare(read_c0_count() + (8* mips_hpt_frequency/HZ));
#ifdef CONFIG_MIPS_MT_FPAFF
/* If we have an FPU, enroll ourselves in the FPU-full mask */
if (cpu_has_fpu)
cpu_set(smp_processor_id(), mt_fpu_cpumask);
#endif /* CONFIG_MIPS_MT_FPAFF */
local_irq_enable();
}
static void vsmp_cpus_done(void)
{
}
/*
* 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
* assumes a 1:1 mapping of TC => VPE
*/
static void __cpuinit vsmp_boot_secondary(int cpu, struct task_struct *idle)
{
struct thread_info *gp = task_thread_info(idle);
dvpe();
set_c0_mvpcontrol(MVPCONTROL_VPC);
settc(cpu);
/* restart */
write_tc_c0_tcrestart((unsigned long)&smp_bootstrap);
/* enable the tc this vpe/cpu will be running */
write_tc_c0_tcstatus((read_tc_c0_tcstatus() & ~TCSTATUS_IXMT) | TCSTATUS_A);
write_tc_c0_tchalt(0);
/* enable the VPE */
write_vpe_c0_vpeconf0(read_vpe_c0_vpeconf0() | VPECONF0_VPA);
/* stack pointer */
write_tc_gpr_sp( __KSTK_TOS(idle));
/* global pointer */
write_tc_gpr_gp((unsigned long)gp);
flush_icache_range((unsigned long)gp,
(unsigned long)(gp + sizeof(struct thread_info)));
/* finally out of configuration and into chaos */
clear_c0_mvpcontrol(MVPCONTROL_VPC);
evpe(EVPE_ENABLE);
}
/*
* Common setup before any secondaries are started
* Make sure all CPU's are in a sensible state before we boot any of the
* secondaries
*/
static void __init vsmp_smp_setup(void)
{
unsigned int mvpconf0, ntc, tc, ncpu = 0;
unsigned int nvpe;
#ifdef CONFIG_MIPS_MT_FPAFF
/* If we have an FPU, enroll ourselves in the FPU-full mask */
if (cpu_has_fpu)
cpu_set(0, mt_fpu_cpumask);
#endif /* CONFIG_MIPS_MT_FPAFF */
if (!cpu_has_mipsmt)
return;
/* disable MT so we can configure */
dvpe();
dmt();
/* Put MVPE's into 'configuration state' */
set_c0_mvpcontrol(MVPCONTROL_VPC);
mvpconf0 = read_c0_mvpconf0();
ntc = (mvpconf0 & MVPCONF0_PTC) >> MVPCONF0_PTC_SHIFT;
nvpe = ((mvpconf0 & MVPCONF0_PVPE) >> MVPCONF0_PVPE_SHIFT) + 1;
smp_num_siblings = nvpe;
/* we'll always have more TC's than VPE's, so loop setting everything
to a sensible state */
for (tc = 0; tc <= ntc; tc++) {
settc(tc);
smvp_tc_init(tc, mvpconf0);
ncpu = smvp_vpe_init(tc, mvpconf0, ncpu);
}
/* Release config state */
clear_c0_mvpcontrol(MVPCONTROL_VPC);
/* We'll wait until starting the secondaries before starting MVPE */
printk(KERN_INFO "Detected %i available secondary CPU(s)\n", ncpu);
}
static void __init vsmp_prepare_cpus(unsigned int max_cpus)
{
mips_mt_set_cpuoptions();
}
struct plat_smp_ops vsmp_smp_ops = {
.send_ipi_single = vsmp_send_ipi_single,
.send_ipi_mask = vsmp_send_ipi_mask,
.init_secondary = vsmp_init_secondary,
.smp_finish = vsmp_smp_finish,
.cpus_done = vsmp_cpus_done,
.boot_secondary = vsmp_boot_secondary,
.smp_setup = vsmp_smp_setup,
.prepare_cpus = vsmp_prepare_cpus,
};