mirror of
https://github.com/adulau/aha.git
synced 2024-12-28 19:56:18 +00:00
578d36f5e1
When testing PREEMPT_RT kernel on BF561-EZKit, the kernel blocks while booting. When the kernel initializes the ethernet driver, it sleeps and never wakes up. The issue happens when the kernel waits for a timer for Core B to timeout (the timers are per-cpu based: static DEFINE_PER_CPU(struct tvec_base *, tvec_bases) = &boot_tvec_bases). However, the ksoftirqd thread for Core B (note, the ksoftirqd thread is also per-cpu based) cannot work properly, and the timers for Core B never times out. When ksoftirqd() for the first time runs on core B, it is possible core A is still initializing core B (see smp_init() -> cpu_up() -> __cpu_up()). So the "cpu_is_offline()" check may return true and ksoftirqd moves to "wait_to_die". So delay the core b start up until the per-cpu timers have been set up fully. Signed-off-by: Yi Li <yi.li@analog.com> Signed-off-by: Mike Frysinger <vapier@gentoo.org>
149 lines
3.6 KiB
C
149 lines
3.6 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>
|
|
|
|
static DEFINE_SPINLOCK(boot_lock);
|
|
|
|
static cpumask_t cpu_callin_map;
|
|
|
|
/*
|
|
* 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. */
|
|
cpu_set(cpu, cpu_callin_map);
|
|
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_isset(cpu, cpu_callin_map))
|
|
break;
|
|
udelay(100);
|
|
barrier();
|
|
}
|
|
|
|
if (cpu_isset(cpu, cpu_callin_map)) {
|
|
cpu_set(cpu, cpu_online_map);
|
|
/* 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();
|
|
}
|