linux/arch/mips/kernel/smp-mt.c
Steven J. Hill 5cf8b2409c MIPS: GIC: Send IPIs using the GIC
If GIC is present, then use it to send IPIs between the cores.
Using GIC for IPIs is simpler and is usable for multicore
systems compared to the existing way of doing IPIs where all VPEs
had to be disabled for another VPE to access the Cause register
in one of the TCs and enable all the VPEs back.

Signed-off-by: Steven J. Hill <Steven.Hill@imgtec.com>
Signed-off-by: Markos Chandras <markos.chandras@imgtec.com>
Signed-off-by: John Crispin <blogic@openwrt.org>
Patchwork: http://patchwork.linux-mips.org/patch/6040/
2014-01-22 20:18:57 +01:00

316 lines
7.6 KiB
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 <linux/atomic.h>
#include <asm/cacheflush.h>
#include <asm/cpu.h>
#include <asm/processor.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>
#include <asm/gic.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);
set_cpu_present(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);
}
#ifdef CONFIG_IRQ_GIC
static void mp_send_ipi_single(int cpu, unsigned int action)
{
unsigned long flags;
local_irq_save(flags);
switch (action) {
case SMP_CALL_FUNCTION:
gic_send_ipi(plat_ipi_call_int_xlate(cpu));
break;
case SMP_RESCHEDULE_YOURSELF:
gic_send_ipi(plat_ipi_resched_int_xlate(cpu));
break;
}
local_irq_restore(flags);
}
#endif
static void vsmp_send_ipi_single(int cpu, unsigned int action)
{
int i;
unsigned long flags;
int vpflags;
#ifdef CONFIG_IRQ_GIC
if (gic_present) {
mp_send_ipi_single(cpu, action);
return;
}
#endif
local_irq_save(flags);
vpflags = dvpe(); /* can't 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 vsmp_init_secondary(void)
{
#ifdef CONFIG_IRQ_GIC
/* This is Malta specific: IPI,performance and timer interrupts */
if (gic_present)
change_c0_status(ST0_IM, STATUSF_IP3 | STATUSF_IP4 |
STATUSF_IP6 | STATUSF_IP7);
else
#endif
change_c0_status(ST0_IM, STATUSF_IP0 | STATUSF_IP1 |
STATUSF_IP6 | STATUSF_IP7);
}
static void 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 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,
};