linux/arch/blackfin/mach-bf561/smp.c
Yi Li 0d152c27e3 Blackfin: SMP: make core timers per-cpu clock events for HRT
SMP systems require per-cpu local clock event devices in order to enable
HRT support.  One a BF561, we can use local core timer for this purpose.
Originally, there was one global core-timer clock event device set up for
core A.

To accomplish this feat, we need to split the gptimer0/core timer logic
so that each is a standalone clock event.  There is no requirement that
we only have one clock event source anyways.  Once we have this, we just
define per-cpu clock event devices for each local core timer.

Signed-off-by: Yi Li <yi.li@analog.com>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
2010-03-09 00:30:48 -05:00

165 lines
3.9 KiB
C

/*
* Copyright 2007-2009 Analog Devices Inc.
* Philippe Gerum <rpm@xenomai.org>
*
* Licensed under the GPL-2 or later.
*/
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/sched.h>
#include <linux/delay.h>
#include <asm/smp.h>
#include <asm/dma.h>
#include <asm/time.h>
static DEFINE_SPINLOCK(boot_lock);
/*
* platform_init_cpus() - Tell the world about how many cores we
* have. This is called while setting up the architecture support
* (setup_arch()), so don't be too demanding here with respect to
* available kernel services.
*/
void __init platform_init_cpus(void)
{
cpu_set(0, cpu_possible_map); /* CoreA */
cpu_set(1, cpu_possible_map); /* CoreB */
}
void __init platform_prepare_cpus(unsigned int max_cpus)
{
int len;
len = &coreb_trampoline_end - &coreb_trampoline_start + 1;
BUG_ON(len > L1_CODE_LENGTH);
dma_memcpy((void *)COREB_L1_CODE_START, &coreb_trampoline_start, len);
/* Both cores ought to be present on a bf561! */
cpu_set(0, cpu_present_map); /* CoreA */
cpu_set(1, cpu_present_map); /* CoreB */
printk(KERN_INFO "CoreB bootstrap code to SRAM %p via DMA.\n", (void *)COREB_L1_CODE_START);
}
int __init setup_profiling_timer(unsigned int multiplier) /* not supported */
{
return -EINVAL;
}
void __cpuinit platform_secondary_init(unsigned int cpu)
{
/* Clone setup for peripheral interrupt sources from CoreA. */
bfin_write_SICB_IMASK0(bfin_read_SICA_IMASK0());
bfin_write_SICB_IMASK1(bfin_read_SICA_IMASK1());
SSYNC();
/* Clone setup for IARs from CoreA. */
bfin_write_SICB_IAR0(bfin_read_SICA_IAR0());
bfin_write_SICB_IAR1(bfin_read_SICA_IAR1());
bfin_write_SICB_IAR2(bfin_read_SICA_IAR2());
bfin_write_SICB_IAR3(bfin_read_SICA_IAR3());
bfin_write_SICB_IAR4(bfin_read_SICA_IAR4());
bfin_write_SICB_IAR5(bfin_read_SICA_IAR5());
bfin_write_SICB_IAR6(bfin_read_SICA_IAR6());
bfin_write_SICB_IAR7(bfin_read_SICA_IAR7());
SSYNC();
/* Store CPU-private information to the cpu_data array. */
bfin_setup_cpudata(cpu);
/* We are done with local CPU inits, unblock the boot CPU. */
set_cpu_online(cpu, true);
spin_lock(&boot_lock);
spin_unlock(&boot_lock);
}
int __cpuinit platform_boot_secondary(unsigned int cpu, struct task_struct *idle)
{
unsigned long timeout;
/* CoreB already running?! */
BUG_ON((bfin_read_SICA_SYSCR() & COREB_SRAM_INIT) == 0);
printk(KERN_INFO "Booting Core B.\n");
spin_lock(&boot_lock);
/* Kick CoreB, which should start execution from CORE_SRAM_BASE. */
SSYNC();
bfin_write_SICA_SYSCR(bfin_read_SICA_SYSCR() & ~COREB_SRAM_INIT);
SSYNC();
timeout = jiffies + 1 * HZ;
while (time_before(jiffies, timeout)) {
if (cpu_online(cpu))
break;
udelay(100);
barrier();
}
if (cpu_online(cpu)) {
/* release the lock and let coreb run */
spin_unlock(&boot_lock);
return 0;
} else
panic("CPU%u: processor failed to boot\n", cpu);
}
void __init platform_request_ipi(irq_handler_t handler)
{
int ret;
ret = request_irq(IRQ_SUPPLE_0, handler, IRQF_DISABLED,
"Supplemental Interrupt0", handler);
if (ret)
panic("Cannot request supplemental interrupt 0 for IPI service");
}
void platform_send_ipi(cpumask_t callmap)
{
unsigned int cpu;
for_each_cpu_mask(cpu, callmap) {
BUG_ON(cpu >= 2);
SSYNC();
bfin_write_SICB_SYSCR(bfin_read_SICB_SYSCR() | (1 << (6 + cpu)));
SSYNC();
}
}
void platform_send_ipi_cpu(unsigned int cpu)
{
BUG_ON(cpu >= 2);
SSYNC();
bfin_write_SICB_SYSCR(bfin_read_SICB_SYSCR() | (1 << (6 + cpu)));
SSYNC();
}
void platform_clear_ipi(unsigned int cpu)
{
BUG_ON(cpu >= 2);
SSYNC();
bfin_write_SICB_SYSCR(bfin_read_SICB_SYSCR() | (1 << (10 + cpu)));
SSYNC();
}
/*
* Setup core B's local core timer.
* In SMP, core timer is used for clock event device.
*/
void __cpuinit bfin_local_timer_setup(void)
{
#if defined(CONFIG_TICKSOURCE_CORETMR)
bfin_coretmr_init();
bfin_coretmr_clockevent_init();
get_irq_chip(IRQ_CORETMR)->unmask(IRQ_CORETMR);
#else
/* Power down the core timer, just to play safe. */
bfin_write_TCNTL(0);
#endif
}