diff options
Diffstat (limited to 'kernel/arch/arc/plat-arcfpga/smp.c')
| -rw-r--r-- | kernel/arch/arc/plat-arcfpga/smp.c | 186 |
1 files changed, 186 insertions, 0 deletions
diff --git a/kernel/arch/arc/plat-arcfpga/smp.c b/kernel/arch/arc/plat-arcfpga/smp.c new file mode 100644 index 000000000..64797ba3b --- /dev/null +++ b/kernel/arch/arc/plat-arcfpga/smp.c @@ -0,0 +1,186 @@ +/* + * 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); +} |