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/*
* ARC700 Simulation-only Extensions for SMP
*
* Copyright (C) 2004, 2007-2010, 2011-2012 Synopsys, Inc. (www.synopsys.com)
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*
* Vineet Gupta - 2012 : split off arch common and plat specific SMP
* Rajeshwar Ranga - 2007 : Interrupt Distribution Unit API's
*/
#include <linux/smp.h>
#include <linux/irq.h>
#include <plat/smp.h>
#define IDU_INTERRUPT_0 16
static char smp_cpuinfo_buf[128];
/*
*-------------------------------------------------------------------
* Platform specific callbacks expected by arch SMP code
*-------------------------------------------------------------------
*/
/*
* Master kick starting another CPU
*/
static void iss_model_smp_wakeup_cpu(int cpu, unsigned long pc)
{
/* setup the start PC */
write_aux_reg(ARC_AUX_XTL_REG_PARAM, pc);
/* Trigger WRITE_PC cmd for this cpu */
write_aux_reg(ARC_AUX_XTL_REG_CMD,
(ARC_XTL_CMD_WRITE_PC | (cpu << 8)));
/* Take the cpu out of Halt */
write_aux_reg(ARC_AUX_XTL_REG_CMD,
(ARC_XTL_CMD_CLEAR_HALT | (cpu << 8)));
}
static inline int get_hw_config_num_irq(void)
{
uint32_t val = read_aux_reg(ARC_REG_VECBASE_BCR);
switch (val & 0x03) {
case 0:
return 16;
case 1:
return 32;
case 2:
return 8;
default:
return 0;
}
return 0;
}
/*
* Any SMP specific init any CPU does when it comes up.
* Here we setup the CPU to enable Inter-Processor-Interrupts
* Called for each CPU
* -Master : init_IRQ()
* -Other(s) : start_kernel_secondary()
*/
void iss_model_init_smp(unsigned int cpu)
{
/* Check if CPU is configured for more than 16 interrupts */
if (NR_IRQS <= 16 || get_hw_config_num_irq() <= 16)
panic("[arcfpga] IRQ system can't support IDU IPI\n");
idu_disable();
/****************************************************************
* IDU provides a set of Common IRQs, each of which can be dynamically
* attached to (1|many|all) CPUs.
* The Common IRQs [0-15] are mapped as CPU pvt [16-31]
*
* Here we use a simple 1:1 mapping:
* A CPU 'x' is wired to Common IRQ 'x'.
* So an IDU ASSERT on IRQ 'x' will trigger Interupt on CPU 'x', which
* makes up for our simple IPI plumbing.
*
* TBD: Have a dedicated multicast IRQ for sending IPIs to all CPUs
* w/o having to do one-at-a-time
******************************************************************/
/*
* Claim an IRQ which would trigger IPI on this CPU.
* In IDU parlance it involves setting up a cpu bitmask for the IRQ
* The bitmap here contains only 1 CPU (self).
*/
idu_irq_set_tgtcpu(cpu, 0x1 << cpu);
/* Set the IRQ destination to use the bitmask above */
idu_irq_set_mode(cpu, 7, /* XXX: IDU_IRQ_MOD_TCPU_ALLRECP: ISS bug */
IDU_IRQ_MODE_PULSE_TRIG);
idu_enable();
/* Attach the arch-common IPI ISR to our IDU IRQ */
smp_ipi_irq_setup(cpu, IDU_INTERRUPT_0 + cpu);
}
static void iss_model_ipi_send(int cpu)
{
idu_irq_assert(cpu);
}
static void iss_model_ipi_clear(int irq)
{
idu_irq_clear(IDU_INTERRUPT_0 + smp_processor_id());
}
void iss_model_init_early_smp(void)
{
#define IS_AVAIL1(var, str) ((var) ? str : "")
struct bcr_mp mp;
READ_BCR(ARC_REG_MP_BCR, mp);
sprintf(smp_cpuinfo_buf, "Extn [ISS-SMP]: v%d, arch(%d) %s %s %s\n",
mp.ver, mp.mp_arch, IS_AVAIL1(mp.scu, "SCU"),
IS_AVAIL1(mp.idu, "IDU"), IS_AVAIL1(mp.sdu, "SDU"));
plat_smp_ops.info = smp_cpuinfo_buf;
plat_smp_ops.cpu_kick = iss_model_smp_wakeup_cpu;
plat_smp_ops.ipi_send = iss_model_ipi_send;
plat_smp_ops.ipi_clear = iss_model_ipi_clear;
}
/*
*-------------------------------------------------------------------
* Low level Platform IPI Providers
*-------------------------------------------------------------------
*/
/* Set the Mode for the Common IRQ */
void idu_irq_set_mode(uint8_t irq, uint8_t dest_mode, uint8_t trig_mode)
{
uint32_t par = IDU_IRQ_MODE_PARAM(dest_mode, trig_mode);
IDU_SET_PARAM(par);
IDU_SET_COMMAND(irq, IDU_IRQ_WMODE);
}
/* Set the target cpu Bitmask for Common IRQ */
void idu_irq_set_tgtcpu(uint8_t irq, uint32_t mask)
{
IDU_SET_PARAM(mask);
IDU_SET_COMMAND(irq, IDU_IRQ_WBITMASK);
}
/* Get the Interrupt Acknowledged status for IRQ (as CPU Bitmask) */
bool idu_irq_get_ack(uint8_t irq)
{
uint32_t val;
IDU_SET_COMMAND(irq, IDU_IRQ_ACK);
val = IDU_GET_PARAM();
return val & (1 << irq);
}
/*
* Get the Interrupt Pending status for IRQ (as CPU Bitmask)
* -Pending means CPU has not yet noticed the IRQ (e.g. disabled)
* -After Interrupt has been taken, the IPI expcitily needs to be
* cleared, to be acknowledged.
*/
bool idu_irq_get_pend(uint8_t irq)
{
uint32_t val;
IDU_SET_COMMAND(irq, IDU_IRQ_PEND);
val = IDU_GET_PARAM();
return val & (1 << irq);
}
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