From 76cb841cb886eef6b3bee341a2266c76578724ad Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Mon, 6 May 2024 03:02:30 +0200 Subject: Adding upstream version 4.19.249. Signed-off-by: Daniel Baumann --- arch/arc/kernel/mcip.c | 376 +++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 376 insertions(+) create mode 100644 arch/arc/kernel/mcip.c (limited to 'arch/arc/kernel/mcip.c') diff --git a/arch/arc/kernel/mcip.c b/arch/arc/kernel/mcip.c new file mode 100644 index 000000000..5fe84e481 --- /dev/null +++ b/arch/arc/kernel/mcip.c @@ -0,0 +1,376 @@ +/* + * ARC ARConnect (MultiCore IP) support (formerly known as MCIP) + * + * Copyright (C) 2013 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. + */ + +#include +#include +#include +#include +#include +#include +#include + +static DEFINE_RAW_SPINLOCK(mcip_lock); + +#ifdef CONFIG_SMP + +static char smp_cpuinfo_buf[128]; + +/* + * Set mask to halt GFRC if any online core in SMP cluster is halted. + * Only works for ARC HS v3.0+, on earlier versions has no effect. + */ +static void mcip_update_gfrc_halt_mask(int cpu) +{ + struct bcr_generic gfrc; + unsigned long flags; + u32 gfrc_halt_mask; + + READ_BCR(ARC_REG_GFRC_BUILD, gfrc); + + /* + * CMD_GFRC_SET_CORE and CMD_GFRC_READ_CORE commands were added in + * GFRC 0x3 version. + */ + if (gfrc.ver < 0x3) + return; + + raw_spin_lock_irqsave(&mcip_lock, flags); + + __mcip_cmd(CMD_GFRC_READ_CORE, 0); + gfrc_halt_mask = read_aux_reg(ARC_REG_MCIP_READBACK); + gfrc_halt_mask |= BIT(cpu); + __mcip_cmd_data(CMD_GFRC_SET_CORE, 0, gfrc_halt_mask); + + raw_spin_unlock_irqrestore(&mcip_lock, flags); +} + +static void mcip_update_debug_halt_mask(int cpu) +{ + u32 mcip_mask = 0; + unsigned long flags; + + raw_spin_lock_irqsave(&mcip_lock, flags); + + /* + * mcip_mask is same for CMD_DEBUG_SET_SELECT and CMD_DEBUG_SET_MASK + * commands. So read it once instead of reading both CMD_DEBUG_READ_MASK + * and CMD_DEBUG_READ_SELECT. + */ + __mcip_cmd(CMD_DEBUG_READ_SELECT, 0); + mcip_mask = read_aux_reg(ARC_REG_MCIP_READBACK); + + mcip_mask |= BIT(cpu); + + __mcip_cmd_data(CMD_DEBUG_SET_SELECT, 0, mcip_mask); + /* + * Parameter specified halt cause: + * STATUS32[H]/actionpoint/breakpoint/self-halt + * We choose all of them (0xF). + */ + __mcip_cmd_data(CMD_DEBUG_SET_MASK, 0xF, mcip_mask); + + raw_spin_unlock_irqrestore(&mcip_lock, flags); +} + +static void mcip_setup_per_cpu(int cpu) +{ + struct mcip_bcr mp; + + READ_BCR(ARC_REG_MCIP_BCR, mp); + + smp_ipi_irq_setup(cpu, IPI_IRQ); + smp_ipi_irq_setup(cpu, SOFTIRQ_IRQ); + + /* Update GFRC halt mask as new CPU came online */ + if (mp.gfrc) + mcip_update_gfrc_halt_mask(cpu); + + /* Update MCIP debug mask as new CPU came online */ + if (mp.dbg) + mcip_update_debug_halt_mask(cpu); +} + +static void mcip_ipi_send(int cpu) +{ + unsigned long flags; + int ipi_was_pending; + + /* ARConnect can only send IPI to others */ + if (unlikely(cpu == raw_smp_processor_id())) { + arc_softirq_trigger(SOFTIRQ_IRQ); + return; + } + + raw_spin_lock_irqsave(&mcip_lock, flags); + + /* + * If receiver already has a pending interrupt, elide sending this one. + * Linux cross core calling works well with concurrent IPIs + * coalesced into one + * see arch/arc/kernel/smp.c: ipi_send_msg_one() + */ + __mcip_cmd(CMD_INTRPT_READ_STATUS, cpu); + ipi_was_pending = read_aux_reg(ARC_REG_MCIP_READBACK); + if (!ipi_was_pending) + __mcip_cmd(CMD_INTRPT_GENERATE_IRQ, cpu); + + raw_spin_unlock_irqrestore(&mcip_lock, flags); +} + +static void mcip_ipi_clear(int irq) +{ + unsigned int cpu, c; + unsigned long flags; + + if (unlikely(irq == SOFTIRQ_IRQ)) { + arc_softirq_clear(irq); + return; + } + + raw_spin_lock_irqsave(&mcip_lock, flags); + + /* Who sent the IPI */ + __mcip_cmd(CMD_INTRPT_CHECK_SOURCE, 0); + + cpu = read_aux_reg(ARC_REG_MCIP_READBACK); /* 1,2,4,8... */ + + /* + * In rare case, multiple concurrent IPIs sent to same target can + * possibly be coalesced by MCIP into 1 asserted IRQ, so @cpus can be + * "vectored" (multiple bits sets) as opposed to typical single bit + */ + do { + c = __ffs(cpu); /* 0,1,2,3 */ + __mcip_cmd(CMD_INTRPT_GENERATE_ACK, c); + cpu &= ~(1U << c); + } while (cpu); + + raw_spin_unlock_irqrestore(&mcip_lock, flags); +} + +static void mcip_probe_n_setup(void) +{ + struct mcip_bcr mp; + + READ_BCR(ARC_REG_MCIP_BCR, mp); + + sprintf(smp_cpuinfo_buf, + "Extn [SMP]\t: ARConnect (v%d): %d cores with %s%s%s%s\n", + mp.ver, mp.num_cores, + IS_AVAIL1(mp.ipi, "IPI "), + IS_AVAIL1(mp.idu, "IDU "), + IS_AVAIL1(mp.dbg, "DEBUG "), + IS_AVAIL1(mp.gfrc, "GFRC")); + + cpuinfo_arc700[0].extn.gfrc = mp.gfrc; +} + +struct plat_smp_ops plat_smp_ops = { + .info = smp_cpuinfo_buf, + .init_early_smp = mcip_probe_n_setup, + .init_per_cpu = mcip_setup_per_cpu, + .ipi_send = mcip_ipi_send, + .ipi_clear = mcip_ipi_clear, +}; + +#endif + +/*************************************************************************** + * ARCv2 Interrupt Distribution Unit (IDU) + * + * Connects external "COMMON" IRQs to core intc, providing: + * -dynamic routing (IRQ affinity) + * -load balancing (Round Robin interrupt distribution) + * -1:N distribution + * + * It physically resides in the MCIP hw block + */ + +#include +#include +#include + +/* + * Set the DEST for @cmn_irq to @cpu_mask (1 bit per core) + */ +static void idu_set_dest(unsigned int cmn_irq, unsigned int cpu_mask) +{ + __mcip_cmd_data(CMD_IDU_SET_DEST, cmn_irq, cpu_mask); +} + +static void idu_set_mode(unsigned int cmn_irq, unsigned int lvl, + unsigned int distr) +{ + union { + unsigned int word; + struct { + unsigned int distr:2, pad:2, lvl:1, pad2:27; + }; + } data; + + data.distr = distr; + data.lvl = lvl; + __mcip_cmd_data(CMD_IDU_SET_MODE, cmn_irq, data.word); +} + +static void idu_irq_mask_raw(irq_hw_number_t hwirq) +{ + unsigned long flags; + + raw_spin_lock_irqsave(&mcip_lock, flags); + __mcip_cmd_data(CMD_IDU_SET_MASK, hwirq, 1); + raw_spin_unlock_irqrestore(&mcip_lock, flags); +} + +static void idu_irq_mask(struct irq_data *data) +{ + idu_irq_mask_raw(data->hwirq); +} + +static void idu_irq_unmask(struct irq_data *data) +{ + unsigned long flags; + + raw_spin_lock_irqsave(&mcip_lock, flags); + __mcip_cmd_data(CMD_IDU_SET_MASK, data->hwirq, 0); + raw_spin_unlock_irqrestore(&mcip_lock, flags); +} + +static int +idu_irq_set_affinity(struct irq_data *data, const struct cpumask *cpumask, + bool force) +{ + unsigned long flags; + cpumask_t online; + unsigned int destination_bits; + unsigned int distribution_mode; + + /* errout if no online cpu per @cpumask */ + if (!cpumask_and(&online, cpumask, cpu_online_mask)) + return -EINVAL; + + raw_spin_lock_irqsave(&mcip_lock, flags); + + destination_bits = cpumask_bits(&online)[0]; + idu_set_dest(data->hwirq, destination_bits); + + if (ffs(destination_bits) == fls(destination_bits)) + distribution_mode = IDU_M_DISTRI_DEST; + else + distribution_mode = IDU_M_DISTRI_RR; + + idu_set_mode(data->hwirq, IDU_M_TRIG_LEVEL, distribution_mode); + + raw_spin_unlock_irqrestore(&mcip_lock, flags); + + return IRQ_SET_MASK_OK; +} + +static void idu_irq_enable(struct irq_data *data) +{ + /* + * By default send all common interrupts to all available online CPUs. + * The affinity of common interrupts in IDU must be set manually since + * in some cases the kernel will not call irq_set_affinity() by itself: + * 1. When the kernel is not configured with support of SMP. + * 2. When the kernel is configured with support of SMP but upper + * interrupt controllers does not support setting of the affinity + * and cannot propagate it to IDU. + */ + idu_irq_set_affinity(data, cpu_online_mask, false); + idu_irq_unmask(data); +} + +static struct irq_chip idu_irq_chip = { + .name = "MCIP IDU Intc", + .irq_mask = idu_irq_mask, + .irq_unmask = idu_irq_unmask, + .irq_enable = idu_irq_enable, +#ifdef CONFIG_SMP + .irq_set_affinity = idu_irq_set_affinity, +#endif + +}; + +static void idu_cascade_isr(struct irq_desc *desc) +{ + struct irq_domain *idu_domain = irq_desc_get_handler_data(desc); + struct irq_chip *core_chip = irq_desc_get_chip(desc); + irq_hw_number_t core_hwirq = irqd_to_hwirq(irq_desc_get_irq_data(desc)); + irq_hw_number_t idu_hwirq = core_hwirq - FIRST_EXT_IRQ; + + chained_irq_enter(core_chip, desc); + generic_handle_irq(irq_find_mapping(idu_domain, idu_hwirq)); + chained_irq_exit(core_chip, desc); +} + +static int idu_irq_map(struct irq_domain *d, unsigned int virq, irq_hw_number_t hwirq) +{ + irq_set_chip_and_handler(virq, &idu_irq_chip, handle_level_irq); + irq_set_status_flags(virq, IRQ_MOVE_PCNTXT); + + return 0; +} + +static const struct irq_domain_ops idu_irq_ops = { + .xlate = irq_domain_xlate_onecell, + .map = idu_irq_map, +}; + +/* + * [16, 23]: Statically assigned always private-per-core (Timers, WDT, IPI) + * [24, 23+C]: If C > 0 then "C" common IRQs + * [24+C, N]: Not statically assigned, private-per-core + */ + + +static int __init +idu_of_init(struct device_node *intc, struct device_node *parent) +{ + struct irq_domain *domain; + int nr_irqs; + int i, virq; + struct mcip_bcr mp; + struct mcip_idu_bcr idu_bcr; + + READ_BCR(ARC_REG_MCIP_BCR, mp); + + if (!mp.idu) + panic("IDU not detected, but DeviceTree using it"); + + READ_BCR(ARC_REG_MCIP_IDU_BCR, idu_bcr); + nr_irqs = mcip_idu_bcr_to_nr_irqs(idu_bcr); + + pr_info("MCIP: IDU supports %u common irqs\n", nr_irqs); + + domain = irq_domain_add_linear(intc, nr_irqs, &idu_irq_ops, NULL); + + /* Parent interrupts (core-intc) are already mapped */ + + for (i = 0; i < nr_irqs; i++) { + /* Mask all common interrupts by default */ + idu_irq_mask_raw(i); + + /* + * Return parent uplink IRQs (towards core intc) 24,25,..... + * this step has been done before already + * however we need it to get the parent virq and set IDU handler + * as first level isr + */ + virq = irq_create_mapping(NULL, i + FIRST_EXT_IRQ); + BUG_ON(!virq); + irq_set_chained_handler_and_data(virq, idu_cascade_isr, domain); + } + + __mcip_cmd(CMD_IDU_ENABLE, 0); + + return 0; +} +IRQCHIP_DECLARE(arcv2_idu_intc, "snps,archs-idu-intc", idu_of_init); -- cgit v1.2.3