/*
* 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) 2007 MIPS Technologies, Inc.
* Chris Dearman (chris@mips.com)
*/
#undef DEBUG
#include <linux/kernel.h>
#include <linux/sched.h>
#include <linux/smp.h>
#include <linux/cpumask.h>
#include <linux/interrupt.h>
#include <linux/compiler.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/smp.h>
#include <asm/time.h>
#include <asm/mipsregs.h>
#include <asm/mipsmtregs.h>
#include <asm/mips_mt.h>
/*
* Crude manipulation of the CPU masks to control which
* which CPU's are brought online during initialisation
*
* Beware... this needs to be called after CPU discovery
* but before CPU bringup
*/
static int __init allowcpus(char *str)
{
cpumask_t cpu_allow_map;
char buf[256];
int len;
cpus_clear(cpu_allow_map);
if (cpulist_parse(str, &cpu_allow_map) == 0) {
cpu_set(0, cpu_allow_map);
cpus_and(cpu_possible_map, cpu_possible_map, cpu_allow_map);
len = cpulist_scnprintf(buf, sizeof(buf)-1, &cpu_possible_map);
buf[len] = '\0';
pr_debug("Allowable CPUs: %s\n", buf);
return 1;
} else
return 0;
}
__setup("allowcpus=", allowcpus);
static void ipi_call_function(unsigned int cpu)
{
unsigned int action = 0;
pr_debug("CPU%d: %s cpu %d status %08x\n",
smp_processor_id(), __func__, cpu, read_c0_status());
switch (cpu) {
case 0:
action = GIC_IPI_EXT_INTR_CALLFNC_VPE0;
break;
case 1:
action = GIC_IPI_EXT_INTR_CALLFNC_VPE1;
break;
case 2:
action = GIC_IPI_EXT_INTR_CALLFNC_VPE2;
break;
case 3:
action = GIC_IPI_EXT_INTR_CALLFNC_VPE3;
break;
}
gic_send_ipi(action);
}
static void ipi_resched(unsigned int cpu)
{
unsigned int action = 0;
pr_debug("CPU%d: %s cpu %d status %08x\n",
smp_processor_id(), __func__, cpu, read_c0_status());
switch (cpu) {
case 0:
action = GIC_IPI_EXT_INTR_RESCHED_VPE0;
break;
case 1:
action = GIC_IPI_EXT_INTR_RESCHED_VPE1;
break;
case 2:
action = GIC_IPI_EXT_INTR_RESCHED_VPE2;
break;
case 3:
action = GIC_IPI_EXT_INTR_RESCHED_VPE3;
break;
}
gic_send_ipi(action);
}
/*
* FIXME: This isn't restricted to CMP
* The SMVP kernel could use GIC interrupts if available
*/
void cmp_send_ipi_single(int cpu, unsigned int action)
{
unsigned long flags;
local_irq_save(flags);
switch (action) {
case SMP_CALL_FUNCTION:
ipi_call_function(cpu);
break;
case SMP_RESCHEDULE_YOURSELF:
ipi_resched(cpu);
break;
}
local_irq_restore(flags);
}
static void cmp_send_ipi_mask(cpumask_t mask, unsigned int action)
{
unsigned int i;
for_each_cpu_mask(i, mask)
cmp_send_ipi_single(i, action);
}
static void cmp_init_secondary(void)
{
struct cpuinfo_mips *c = ¤t_cpu_data;
/* Assume GIC is present */
change_c0_status(ST0_IM, STATUSF_IP3 | STATUSF_IP4 | STATUSF_IP6 |
STATUSF_IP7);
/* Enable per-cpu interrupts: platform specific */
c->core = (read_c0_ebase() >> 1) & 0xff;
#if defined(CONFIG_MIPS_MT_SMP) || defined(CONFIG_MIPS_MT_SMTC)
c->vpe_id = (read_c0_tcbind() >> TCBIND_CURVPE_SHIFT) & TCBIND_CURVPE;
#endif
#ifdef CONFIG_MIPS_MT_SMTC
c->tc_id = (read_c0_tcbind() >> TCBIND_CURTC_SHIFT) & TCBIND_CURTC;
#endif
}
static void cmp_smp_finish(void)
{
pr_debug("SMPCMP: CPU%d: %s\n", smp_processor_id(), __func__);
/* 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 cmp_cpus_done(void)
{
pr_debug("SMPCMP: CPU%d: %s\n", smp_processor_id(), __func__);
}
/*
* 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
*/
static void cmp_boot_secondary(int cpu, struct task_struct *idle)
{
struct thread_info *gp = task_thread_info(idle);
unsigned long sp = __KSTK_TOS(idle);
unsigned long pc = (unsigned long)&smp_bootstrap;
unsigned long a0 = 0;
pr_debug("SMPCMP: CPU%d: %s cpu %d\n", smp_processor_id(),
__func__, cpu);
#if 0
/* Needed? */
flush_icache_range((unsigned long)gp,
(unsigned long)(gp + sizeof(struct thread_info)));
#endif
amon_cpu_start(cpu, pc, sp, gp, a0);
}
/*
* Common setup before any secondaries are started
*/
void __init cmp_smp_setup(void)
{
int i;
int ncpu = 0;
pr_debug("SMPCMP: CPU%d: %s\n", smp_processor_id(), __func__);
#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 */
for (i = 1; i < NR_CPUS; i++) {
if (amon_cpu_avail(i)) {
cpu_set(i, cpu_possible_map);
__cpu_number_map[i] = ++ncpu;
__cpu_logical_map[ncpu] = i;
}
}
if (cpu_has_mipsmt) {
unsigned int nvpe, mvpconf0 = read_c0_mvpconf0();
nvpe = ((mvpconf0 & MVPCONF0_PTC) >> MVPCONF0_PTC_SHIFT) + 1;
smp_num_siblings = nvpe;
}
pr_info("Detected %i available secondary CPU(s)\n", ncpu);
}
void __init cmp_prepare_cpus(unsigned int max_cpus)
{
pr_debug("SMPCMP: CPU%d: %s max_cpus=%d\n",
smp_processor_id(), __func__, max_cpus);
/*
* FIXME: some of these options are per-system, some per-core and
* some per-cpu
*/
mips_mt_set_cpuoptions();
}
struct plat_smp_ops cmp_smp_ops = {
.send_ipi_single = cmp_send_ipi_single,
.send_ipi_mask = cmp_send_ipi_mask,
.init_secondary = cmp_init_secondary,
.smp_finish = cmp_smp_finish,
.cpus_done = cmp_cpus_done,
.boot_secondary = cmp_boot_secondary,
.smp_setup = cmp_smp_setup,
.prepare_cpus = cmp_prepare_cpus,
};
