diff options
author | Marc Zyngier <marc.zyngier@arm.com> | 2014-06-30 19:01:31 +0400 |
---|---|---|
committer | Jason Cooper <jason@lakedaemon.net> | 2014-07-09 02:11:47 +0400 |
commit | 021f653791ad17e03f98aaa7fb933816ae16f161 (patch) | |
tree | 76565bc06247be7e4bc6a3479fe6dcd686799c46 /drivers/irqchip/irq-gic-v3.c | |
parent | d51d0af43b30dcae1ca13ea67fd717e03b37f153 (diff) | |
download | linux-021f653791ad17e03f98aaa7fb933816ae16f161.tar.xz |
irqchip: gic-v3: Initial support for GICv3
The Generic Interrupt Controller (version 3) offers services that are
similar to GICv2, with a number of additional features:
- Affinity routing based on the CPU MPIDR (ARE)
- System register for the CPU interfaces (SRE)
- Support for more that 8 CPUs
- Locality-specific Peripheral Interrupts (LPIs)
- Interrupt Translation Services (ITS)
This patch adds preliminary support for GICv3 with ARE and SRE,
non-secure mode only. It relies on higher exception levels to grant ARE
and SRE access.
Support for LPI and ITS will be added at a later time.
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Jason Cooper <jason@lakedaemon.net>
Reviewed-by: Zi Shen Lim <zlim@broadcom.com>
Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
Reviewed-by: Tirumalesh Chalamarla <tchalamarla@cavium.com>
Reviewed-by: Yun Wu <wuyun.wu@huawei.com>
Reviewed-by: Zhen Lei <thunder.leizhen@huawei.com>
Tested-by: Tirumalesh Chalamarla<tchalamarla@cavium.com>
Tested-by: Radha Mohan Chintakuntla <rchintakuntla@cavium.com>
Acked-by: Radha Mohan Chintakuntla <rchintakuntla@cavium.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Reviewed-by: Mark Rutland <mark.rutland@arm.com>
Link: https://lkml.kernel.org/r/1404140510-5382-3-git-send-email-marc.zyngier@arm.com
Signed-off-by: Jason Cooper <jason@lakedaemon.net>
Diffstat (limited to 'drivers/irqchip/irq-gic-v3.c')
-rw-r--r-- | drivers/irqchip/irq-gic-v3.c | 692 |
1 files changed, 692 insertions, 0 deletions
diff --git a/drivers/irqchip/irq-gic-v3.c b/drivers/irqchip/irq-gic-v3.c new file mode 100644 index 000000000000..81519bae0453 --- /dev/null +++ b/drivers/irqchip/irq-gic-v3.c @@ -0,0 +1,692 @@ +/* + * Copyright (C) 2013, 2014 ARM Limited, All Rights Reserved. + * Author: Marc Zyngier <marc.zyngier@arm.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. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program. If not, see <http://www.gnu.org/licenses/>. + */ + +#include <linux/cpu.h> +#include <linux/delay.h> +#include <linux/interrupt.h> +#include <linux/of.h> +#include <linux/of_address.h> +#include <linux/of_irq.h> +#include <linux/percpu.h> +#include <linux/slab.h> + +#include <linux/irqchip/arm-gic-v3.h> + +#include <asm/cputype.h> +#include <asm/exception.h> +#include <asm/smp_plat.h> + +#include "irq-gic-common.h" +#include "irqchip.h" + +struct gic_chip_data { + void __iomem *dist_base; + void __iomem **redist_base; + void __percpu __iomem **rdist; + struct irq_domain *domain; + u64 redist_stride; + u32 redist_regions; + unsigned int irq_nr; +}; + +static struct gic_chip_data gic_data __read_mostly; + +#define gic_data_rdist() (this_cpu_ptr(gic_data.rdist)) +#define gic_data_rdist_rd_base() (*gic_data_rdist()) +#define gic_data_rdist_sgi_base() (gic_data_rdist_rd_base() + SZ_64K) + +/* Our default, arbitrary priority value. Linux only uses one anyway. */ +#define DEFAULT_PMR_VALUE 0xf0 + +static inline unsigned int gic_irq(struct irq_data *d) +{ + return d->hwirq; +} + +static inline int gic_irq_in_rdist(struct irq_data *d) +{ + return gic_irq(d) < 32; +} + +static inline void __iomem *gic_dist_base(struct irq_data *d) +{ + if (gic_irq_in_rdist(d)) /* SGI+PPI -> SGI_base for this CPU */ + return gic_data_rdist_sgi_base(); + + if (d->hwirq <= 1023) /* SPI -> dist_base */ + return gic_data.dist_base; + + if (d->hwirq >= 8192) + BUG(); /* LPI Detected!!! */ + + return NULL; +} + +static void gic_do_wait_for_rwp(void __iomem *base) +{ + u32 count = 1000000; /* 1s! */ + + while (readl_relaxed(base + GICD_CTLR) & GICD_CTLR_RWP) { + count--; + if (!count) { + pr_err_ratelimited("RWP timeout, gone fishing\n"); + return; + } + cpu_relax(); + udelay(1); + }; +} + +/* Wait for completion of a distributor change */ +static void gic_dist_wait_for_rwp(void) +{ + gic_do_wait_for_rwp(gic_data.dist_base); +} + +/* Wait for completion of a redistributor change */ +static void gic_redist_wait_for_rwp(void) +{ + gic_do_wait_for_rwp(gic_data_rdist_rd_base()); +} + +/* Low level accessors */ +static u64 gic_read_iar(void) +{ + u64 irqstat; + + asm volatile("mrs %0, " __stringify(ICC_IAR1_EL1) : "=r" (irqstat)); + return irqstat; +} + +static void gic_write_pmr(u64 val) +{ + asm volatile("msr " __stringify(ICC_PMR_EL1) ", %0" : : "r" (val)); +} + +static void gic_write_ctlr(u64 val) +{ + asm volatile("msr " __stringify(ICC_CTLR_EL1) ", %0" : : "r" (val)); + isb(); +} + +static void gic_write_grpen1(u64 val) +{ + asm volatile("msr " __stringify(ICC_GRPEN1_EL1) ", %0" : : "r" (val)); + isb(); +} + +static void gic_write_sgi1r(u64 val) +{ + asm volatile("msr " __stringify(ICC_SGI1R_EL1) ", %0" : : "r" (val)); +} + +static void gic_enable_sre(void) +{ + u64 val; + + asm volatile("mrs %0, " __stringify(ICC_SRE_EL1) : "=r" (val)); + val |= ICC_SRE_EL1_SRE; + asm volatile("msr " __stringify(ICC_SRE_EL1) ", %0" : : "r" (val)); + isb(); + + /* + * Need to check that the SRE bit has actually been set. If + * not, it means that SRE is disabled at EL2. We're going to + * die painfully, and there is nothing we can do about it. + * + * Kindly inform the luser. + */ + asm volatile("mrs %0, " __stringify(ICC_SRE_EL1) : "=r" (val)); + if (!(val & ICC_SRE_EL1_SRE)) + pr_err("GIC: unable to set SRE (disabled at EL2), panic ahead\n"); +} + +static void gic_enable_redist(void) +{ + void __iomem *rbase; + u32 count = 1000000; /* 1s! */ + u32 val; + + rbase = gic_data_rdist_rd_base(); + + /* Wake up this CPU redistributor */ + val = readl_relaxed(rbase + GICR_WAKER); + val &= ~GICR_WAKER_ProcessorSleep; + writel_relaxed(val, rbase + GICR_WAKER); + + while (readl_relaxed(rbase + GICR_WAKER) & GICR_WAKER_ChildrenAsleep) { + count--; + if (!count) { + pr_err_ratelimited("redist didn't wake up...\n"); + return; + } + cpu_relax(); + udelay(1); + }; +} + +/* + * Routines to disable, enable, EOI and route interrupts + */ +static void gic_poke_irq(struct irq_data *d, u32 offset) +{ + u32 mask = 1 << (gic_irq(d) % 32); + void (*rwp_wait)(void); + void __iomem *base; + + if (gic_irq_in_rdist(d)) { + base = gic_data_rdist_sgi_base(); + rwp_wait = gic_redist_wait_for_rwp; + } else { + base = gic_data.dist_base; + rwp_wait = gic_dist_wait_for_rwp; + } + + writel_relaxed(mask, base + offset + (gic_irq(d) / 32) * 4); + rwp_wait(); +} + +static int gic_peek_irq(struct irq_data *d, u32 offset) +{ + u32 mask = 1 << (gic_irq(d) % 32); + void __iomem *base; + + if (gic_irq_in_rdist(d)) + base = gic_data_rdist_sgi_base(); + else + base = gic_data.dist_base; + + return !!(readl_relaxed(base + offset + (gic_irq(d) / 32) * 4) & mask); +} + +static void gic_mask_irq(struct irq_data *d) +{ + gic_poke_irq(d, GICD_ICENABLER); +} + +static void gic_unmask_irq(struct irq_data *d) +{ + gic_poke_irq(d, GICD_ISENABLER); +} + +static void gic_eoi_irq(struct irq_data *d) +{ + gic_write_eoir(gic_irq(d)); +} + +static int gic_set_type(struct irq_data *d, unsigned int type) +{ + unsigned int irq = gic_irq(d); + void (*rwp_wait)(void); + void __iomem *base; + + /* Interrupt configuration for SGIs can't be changed */ + if (irq < 16) + return -EINVAL; + + if (type != IRQ_TYPE_LEVEL_HIGH && type != IRQ_TYPE_EDGE_RISING) + return -EINVAL; + + if (gic_irq_in_rdist(d)) { + base = gic_data_rdist_sgi_base(); + rwp_wait = gic_redist_wait_for_rwp; + } else { + base = gic_data.dist_base; + rwp_wait = gic_dist_wait_for_rwp; + } + + gic_configure_irq(irq, type, base, rwp_wait); + + return 0; +} + +static u64 gic_mpidr_to_affinity(u64 mpidr) +{ + u64 aff; + + aff = (MPIDR_AFFINITY_LEVEL(mpidr, 3) << 32 | + MPIDR_AFFINITY_LEVEL(mpidr, 2) << 16 | + MPIDR_AFFINITY_LEVEL(mpidr, 1) << 8 | + MPIDR_AFFINITY_LEVEL(mpidr, 0)); + + return aff; +} + +static asmlinkage void __exception_irq_entry gic_handle_irq(struct pt_regs *regs) +{ + u64 irqnr; + + do { + irqnr = gic_read_iar(); + + if (likely(irqnr > 15 && irqnr < 1020)) { + u64 irq = irq_find_mapping(gic_data.domain, irqnr); + if (likely(irq)) { + handle_IRQ(irq, regs); + continue; + } + + WARN_ONCE(true, "Unexpected SPI received!\n"); + gic_write_eoir(irqnr); + } + if (irqnr < 16) { + gic_write_eoir(irqnr); +#ifdef CONFIG_SMP + handle_IPI(irqnr, regs); +#else + WARN_ONCE(true, "Unexpected SGI received!\n"); +#endif + continue; + } + } while (irqnr != ICC_IAR1_EL1_SPURIOUS); +} + +static void __init gic_dist_init(void) +{ + unsigned int i; + u64 affinity; + void __iomem *base = gic_data.dist_base; + + /* Disable the distributor */ + writel_relaxed(0, base + GICD_CTLR); + gic_dist_wait_for_rwp(); + + gic_dist_config(base, gic_data.irq_nr, gic_dist_wait_for_rwp); + + /* Enable distributor with ARE, Group1 */ + writel_relaxed(GICD_CTLR_ARE_NS | GICD_CTLR_ENABLE_G1A | GICD_CTLR_ENABLE_G1, + base + GICD_CTLR); + + /* + * Set all global interrupts to the boot CPU only. ARE must be + * enabled. + */ + affinity = gic_mpidr_to_affinity(cpu_logical_map(smp_processor_id())); + for (i = 32; i < gic_data.irq_nr; i++) + writeq_relaxed(affinity, base + GICD_IROUTER + i * 8); +} + +static int gic_populate_rdist(void) +{ + u64 mpidr = cpu_logical_map(smp_processor_id()); + u64 typer; + u32 aff; + int i; + + /* + * Convert affinity to a 32bit value that can be matched to + * GICR_TYPER bits [63:32]. + */ + aff = (MPIDR_AFFINITY_LEVEL(mpidr, 3) << 24 | + MPIDR_AFFINITY_LEVEL(mpidr, 2) << 16 | + MPIDR_AFFINITY_LEVEL(mpidr, 1) << 8 | + MPIDR_AFFINITY_LEVEL(mpidr, 0)); + + for (i = 0; i < gic_data.redist_regions; i++) { + void __iomem *ptr = gic_data.redist_base[i]; + u32 reg; + + reg = readl_relaxed(ptr + GICR_PIDR2) & GIC_PIDR2_ARCH_MASK; + if (reg != GIC_PIDR2_ARCH_GICv3 && + reg != GIC_PIDR2_ARCH_GICv4) { /* We're in trouble... */ + pr_warn("No redistributor present @%p\n", ptr); + break; + } + + do { + typer = readq_relaxed(ptr + GICR_TYPER); + if ((typer >> 32) == aff) { + gic_data_rdist_rd_base() = ptr; + pr_info("CPU%d: found redistributor %llx @%p\n", + smp_processor_id(), + (unsigned long long)mpidr, ptr); + return 0; + } + + if (gic_data.redist_stride) { + ptr += gic_data.redist_stride; + } else { + ptr += SZ_64K * 2; /* Skip RD_base + SGI_base */ + if (typer & GICR_TYPER_VLPIS) + ptr += SZ_64K * 2; /* Skip VLPI_base + reserved page */ + } + } while (!(typer & GICR_TYPER_LAST)); + } + + /* We couldn't even deal with ourselves... */ + WARN(true, "CPU%d: mpidr %llx has no re-distributor!\n", + smp_processor_id(), (unsigned long long)mpidr); + return -ENODEV; +} + +static void gic_cpu_init(void) +{ + void __iomem *rbase; + + /* Register ourselves with the rest of the world */ + if (gic_populate_rdist()) + return; + + gic_enable_redist(); + + rbase = gic_data_rdist_sgi_base(); + + gic_cpu_config(rbase, gic_redist_wait_for_rwp); + + /* Enable system registers */ + gic_enable_sre(); + + /* Set priority mask register */ + gic_write_pmr(DEFAULT_PMR_VALUE); + + /* EOI deactivates interrupt too (mode 0) */ + gic_write_ctlr(ICC_CTLR_EL1_EOImode_drop_dir); + + /* ... and let's hit the road... */ + gic_write_grpen1(1); +} + +#ifdef CONFIG_SMP +static int gic_secondary_init(struct notifier_block *nfb, + unsigned long action, void *hcpu) +{ + if (action == CPU_STARTING || action == CPU_STARTING_FROZEN) + gic_cpu_init(); + return NOTIFY_OK; +} + +/* + * Notifier for enabling the GIC CPU interface. Set an arbitrarily high + * priority because the GIC needs to be up before the ARM generic timers. + */ +static struct notifier_block gic_cpu_notifier = { + .notifier_call = gic_secondary_init, + .priority = 100, +}; + +static u16 gic_compute_target_list(int *base_cpu, const struct cpumask *mask, + u64 cluster_id) +{ + int cpu = *base_cpu; + u64 mpidr = cpu_logical_map(cpu); + u16 tlist = 0; + + while (cpu < nr_cpu_ids) { + /* + * If we ever get a cluster of more than 16 CPUs, just + * scream and skip that CPU. + */ + if (WARN_ON((mpidr & 0xff) >= 16)) + goto out; + + tlist |= 1 << (mpidr & 0xf); + + cpu = cpumask_next(cpu, mask); + if (cpu == nr_cpu_ids) + goto out; + + mpidr = cpu_logical_map(cpu); + + if (cluster_id != (mpidr & ~0xffUL)) { + cpu--; + goto out; + } + } +out: + *base_cpu = cpu; + return tlist; +} + +static void gic_send_sgi(u64 cluster_id, u16 tlist, unsigned int irq) +{ + u64 val; + + val = (MPIDR_AFFINITY_LEVEL(cluster_id, 3) << 48 | + MPIDR_AFFINITY_LEVEL(cluster_id, 2) << 32 | + irq << 24 | + MPIDR_AFFINITY_LEVEL(cluster_id, 1) << 16 | + tlist); + + pr_debug("CPU%d: ICC_SGI1R_EL1 %llx\n", smp_processor_id(), val); + gic_write_sgi1r(val); +} + +static void gic_raise_softirq(const struct cpumask *mask, unsigned int irq) +{ + int cpu; + + if (WARN_ON(irq >= 16)) + return; + + /* + * Ensure that stores to Normal memory are visible to the + * other CPUs before issuing the IPI. + */ + smp_wmb(); + + for_each_cpu_mask(cpu, *mask) { + u64 cluster_id = cpu_logical_map(cpu) & ~0xffUL; + u16 tlist; + + tlist = gic_compute_target_list(&cpu, mask, cluster_id); + gic_send_sgi(cluster_id, tlist, irq); + } + + /* Force the above writes to ICC_SGI1R_EL1 to be executed */ + isb(); +} + +static void gic_smp_init(void) +{ + set_smp_cross_call(gic_raise_softirq); + register_cpu_notifier(&gic_cpu_notifier); +} + +static int gic_set_affinity(struct irq_data *d, const struct cpumask *mask_val, + bool force) +{ + unsigned int cpu = cpumask_any_and(mask_val, cpu_online_mask); + void __iomem *reg; + int enabled; + u64 val; + + if (gic_irq_in_rdist(d)) + return -EINVAL; + + /* If interrupt was enabled, disable it first */ + enabled = gic_peek_irq(d, GICD_ISENABLER); + if (enabled) + gic_mask_irq(d); + + reg = gic_dist_base(d) + GICD_IROUTER + (gic_irq(d) * 8); + val = gic_mpidr_to_affinity(cpu_logical_map(cpu)); + + writeq_relaxed(val, reg); + + /* + * If the interrupt was enabled, enabled it again. Otherwise, + * just wait for the distributor to have digested our changes. + */ + if (enabled) + gic_unmask_irq(d); + else + gic_dist_wait_for_rwp(); + + return IRQ_SET_MASK_OK; +} +#else +#define gic_set_affinity NULL +#define gic_smp_init() do { } while(0) +#endif + +static struct irq_chip gic_chip = { + .name = "GICv3", + .irq_mask = gic_mask_irq, + .irq_unmask = gic_unmask_irq, + .irq_eoi = gic_eoi_irq, + .irq_set_type = gic_set_type, + .irq_set_affinity = gic_set_affinity, +}; + +static int gic_irq_domain_map(struct irq_domain *d, unsigned int irq, + irq_hw_number_t hw) +{ + /* SGIs are private to the core kernel */ + if (hw < 16) + return -EPERM; + /* PPIs */ + if (hw < 32) { + irq_set_percpu_devid(irq); + irq_set_chip_and_handler(irq, &gic_chip, + handle_percpu_devid_irq); + set_irq_flags(irq, IRQF_VALID | IRQF_NOAUTOEN); + } + /* SPIs */ + if (hw >= 32 && hw < gic_data.irq_nr) { + irq_set_chip_and_handler(irq, &gic_chip, + handle_fasteoi_irq); + set_irq_flags(irq, IRQF_VALID | IRQF_PROBE); + } + irq_set_chip_data(irq, d->host_data); + return 0; +} + +static int gic_irq_domain_xlate(struct irq_domain *d, + struct device_node *controller, + const u32 *intspec, unsigned int intsize, + unsigned long *out_hwirq, unsigned int *out_type) +{ + if (d->of_node != controller) + return -EINVAL; + if (intsize < 3) + return -EINVAL; + + switch(intspec[0]) { + case 0: /* SPI */ + *out_hwirq = intspec[1] + 32; + break; + case 1: /* PPI */ + *out_hwirq = intspec[1] + 16; + break; + default: + return -EINVAL; + } + + *out_type = intspec[2] & IRQ_TYPE_SENSE_MASK; + return 0; +} + +static const struct irq_domain_ops gic_irq_domain_ops = { + .map = gic_irq_domain_map, + .xlate = gic_irq_domain_xlate, +}; + +static int __init gic_of_init(struct device_node *node, struct device_node *parent) +{ + void __iomem *dist_base; + void __iomem **redist_base; + u64 redist_stride; + u32 redist_regions; + u32 reg; + int gic_irqs; + int err; + int i; + + dist_base = of_iomap(node, 0); + if (!dist_base) { + pr_err("%s: unable to map gic dist registers\n", + node->full_name); + return -ENXIO; + } + + reg = readl_relaxed(dist_base + GICD_PIDR2) & GIC_PIDR2_ARCH_MASK; + if (reg != GIC_PIDR2_ARCH_GICv3 && reg != GIC_PIDR2_ARCH_GICv4) { + pr_err("%s: no distributor detected, giving up\n", + node->full_name); + err = -ENODEV; + goto out_unmap_dist; + } + + if (of_property_read_u32(node, "#redistributor-regions", &redist_regions)) + redist_regions = 1; + + redist_base = kzalloc(sizeof(*redist_base) * redist_regions, GFP_KERNEL); + if (!redist_base) { + err = -ENOMEM; + goto out_unmap_dist; + } + + for (i = 0; i < redist_regions; i++) { + redist_base[i] = of_iomap(node, 1 + i); + if (!redist_base[i]) { + pr_err("%s: couldn't map region %d\n", + node->full_name, i); + err = -ENODEV; + goto out_unmap_rdist; + } + } + + if (of_property_read_u64(node, "redistributor-stride", &redist_stride)) + redist_stride = 0; + + gic_data.dist_base = dist_base; + gic_data.redist_base = redist_base; + gic_data.redist_regions = redist_regions; + gic_data.redist_stride = redist_stride; + + /* + * Find out how many interrupts are supported. + * The GIC only supports up to 1020 interrupt sources (SGI+PPI+SPI) + */ + gic_irqs = readl_relaxed(gic_data.dist_base + GICD_TYPER) & 0x1f; + gic_irqs = (gic_irqs + 1) * 32; + if (gic_irqs > 1020) + gic_irqs = 1020; + gic_data.irq_nr = gic_irqs; + + gic_data.domain = irq_domain_add_tree(node, &gic_irq_domain_ops, + &gic_data); + gic_data.rdist = alloc_percpu(typeof(*gic_data.rdist)); + + if (WARN_ON(!gic_data.domain) || WARN_ON(!gic_data.rdist)) { + err = -ENOMEM; + goto out_free; + } + + set_handle_irq(gic_handle_irq); + + gic_smp_init(); + gic_dist_init(); + gic_cpu_init(); + + return 0; + +out_free: + if (gic_data.domain) + irq_domain_remove(gic_data.domain); + free_percpu(gic_data.rdist); +out_unmap_rdist: + for (i = 0; i < redist_regions; i++) + if (redist_base[i]) + iounmap(redist_base[i]); + kfree(redist_base); +out_unmap_dist: + iounmap(dist_base); + return err; +} + +IRQCHIP_DECLARE(gic_v3, "arm,gic-v3", gic_of_init); |