Re: [PATCH v6 02/21] irqchip: arm64: Initial support for GICv3

[Mark Rutland <mark.rutland@arm.com>]

On Mon, Jun 30, 2014 at 04:01:31PM +0100, Marc Zyngier wrote:
> 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>

One more can't hurt, no?

Reviewed-by: Mark Rutland <mark.rutland@arm.com>

Thanks for making the magic numbers less magic. :)

Mark.

> ---
>  arch/arm64/Kconfig                 |   1 +
>  arch/arm64/kernel/head.S           |  18 +
>  arch/arm64/kernel/hyp-stub.S       |   1 +
>  drivers/irqchip/Kconfig            |   5 +
>  drivers/irqchip/Makefile           |   1 +
>  drivers/irqchip/irq-gic-v3.c       | 692 +++++++++++++++++++++++++++++++++++++
>  include/linux/irqchip/arm-gic-v3.h | 198 +++++++++++
>  7 files changed, 916 insertions(+)
>  create mode 100644 drivers/irqchip/irq-gic-v3.c
>  create mode 100644 include/linux/irqchip/arm-gic-v3.h
> 
> diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
> index 7295419..be52492 100644
> --- a/arch/arm64/Kconfig
> +++ b/arch/arm64/Kconfig
> @@ -9,6 +9,7 @@ config ARM64
>         select ARM_AMBA
>         select ARM_ARCH_TIMER
>         select ARM_GIC
> +       select ARM_GIC_V3
>         select BUILDTIME_EXTABLE_SORT
>         select CLONE_BACKWARDS
>         select COMMON_CLK
> diff --git a/arch/arm64/kernel/head.S b/arch/arm64/kernel/head.S
> index a96d3a6..9662350 100644
> --- a/arch/arm64/kernel/head.S
> +++ b/arch/arm64/kernel/head.S
> @@ -22,6 +22,7 @@
> 
>  #include <linux/linkage.h>
>  #include <linux/init.h>
> +#include <linux/irqchip/arm-gic-v3.h>
> 
>  #include <asm/assembler.h>
>  #include <asm/ptrace.h>
> @@ -296,6 +297,23 @@ CPU_LE(    bic     x0, x0, #(3 << 24)      )       // Clear the EE and E0E bits for EL1
>         msr     cnthctl_el2, x0
>         msr     cntvoff_el2, xzr                // Clear virtual offset
> 
> +#ifdef CONFIG_ARM_GIC_V3
> +       /* GICv3 system register access */
> +       mrs     x0, id_aa64pfr0_el1
> +       ubfx    x0, x0, #24, #4
> +       cmp     x0, #1
> +       b.ne    3f
> +
> +       mrs     x0, ICC_SRE_EL2
> +       orr     x0, x0, #ICC_SRE_EL2_SRE        // Set ICC_SRE_EL2.SRE==1
> +       orr     x0, x0, #ICC_SRE_EL2_ENABLE     // Set ICC_SRE_EL2.Enable==1
> +       msr     ICC_SRE_EL2, x0
> +       isb                                     // Make sure SRE is now set
> +       msr     ICH_HCR_EL2, xzr                // Reset ICC_HCR_EL2 to defaults
> +
> +3:
> +#endif
> +
>         /* Populate ID registers. */
>         mrs     x0, midr_el1
>         mrs     x1, mpidr_el1
> diff --git a/arch/arm64/kernel/hyp-stub.S b/arch/arm64/kernel/hyp-stub.S
> index 0959611..a272f33 100644
> --- a/arch/arm64/kernel/hyp-stub.S
> +++ b/arch/arm64/kernel/hyp-stub.S
> @@ -19,6 +19,7 @@
> 
>  #include <linux/init.h>
>  #include <linux/linkage.h>
> +#include <linux/irqchip/arm-gic-v3.h>
> 
>  #include <asm/assembler.h>
>  #include <asm/ptrace.h>
> diff --git a/drivers/irqchip/Kconfig b/drivers/irqchip/Kconfig
> index bbb746e..7f0c2a3 100644
> --- a/drivers/irqchip/Kconfig
> +++ b/drivers/irqchip/Kconfig
> @@ -10,6 +10,11 @@ config ARM_GIC
>  config GIC_NON_BANKED
>         bool
> 
> +config ARM_GIC_V3
> +       bool
> +       select IRQ_DOMAIN
> +       select MULTI_IRQ_HANDLER
> +
>  config ARM_NVIC
>         bool
>         select IRQ_DOMAIN
> diff --git a/drivers/irqchip/Makefile b/drivers/irqchip/Makefile
> index 9b9505c..c57e642 100644
> --- a/drivers/irqchip/Makefile
> +++ b/drivers/irqchip/Makefile
> @@ -16,6 +16,7 @@ obj-$(CONFIG_ARCH_SUNXI)              += irq-sun4i.o
>  obj-$(CONFIG_ARCH_SUNXI)               += irq-sunxi-nmi.o
>  obj-$(CONFIG_ARCH_SPEAR3XX)            += spear-shirq.o
>  obj-$(CONFIG_ARM_GIC)                  += irq-gic.o irq-gic-common.o
> +obj-$(CONFIG_ARM_GIC_V3)               += irq-gic-v3.o irq-gic-common.o
>  obj-$(CONFIG_ARM_NVIC)                 += irq-nvic.o
>  obj-$(CONFIG_ARM_VIC)                  += irq-vic.o
>  obj-$(CONFIG_IMGPDC_IRQ)               += irq-imgpdc.o
> diff --git a/drivers/irqchip/irq-gic-v3.c b/drivers/irqchip/irq-gic-v3.c
> new file mode 100644
> index 0000000..81519ba
> --- /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);
> diff --git a/include/linux/irqchip/arm-gic-v3.h b/include/linux/irqchip/arm-gic-v3.h
> new file mode 100644
> index 0000000..30cb755
> --- /dev/null
> +++ b/include/linux/irqchip/arm-gic-v3.h
> @@ -0,0 +1,198 @@
> +/*
> + * 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/>.
> + */
> +#ifndef __LINUX_IRQCHIP_ARM_GIC_V3_H
> +#define __LINUX_IRQCHIP_ARM_GIC_V3_H
> +
> +/*
> + * Distributor registers. We assume we're running non-secure, with ARE
> + * being set. Secure-only and non-ARE registers are not described.
> + */
> +#define GICD_CTLR                      0x0000
> +#define GICD_TYPER                     0x0004
> +#define GICD_IIDR                      0x0008
> +#define GICD_STATUSR                   0x0010
> +#define GICD_SETSPI_NSR                        0x0040
> +#define GICD_CLRSPI_NSR                        0x0048
> +#define GICD_SETSPI_SR                 0x0050
> +#define GICD_CLRSPI_SR                 0x0058
> +#define GICD_SEIR                      0x0068
> +#define GICD_ISENABLER                 0x0100
> +#define GICD_ICENABLER                 0x0180
> +#define GICD_ISPENDR                   0x0200
> +#define GICD_ICPENDR                   0x0280
> +#define GICD_ISACTIVER                 0x0300
> +#define GICD_ICACTIVER                 0x0380
> +#define GICD_IPRIORITYR                        0x0400
> +#define GICD_ICFGR                     0x0C00
> +#define GICD_IROUTER                   0x6000
> +#define GICD_PIDR2                     0xFFE8
> +
> +#define GICD_CTLR_RWP                  (1U << 31)
> +#define GICD_CTLR_ARE_NS               (1U << 4)
> +#define GICD_CTLR_ENABLE_G1A           (1U << 1)
> +#define GICD_CTLR_ENABLE_G1            (1U << 0)
> +
> +#define GICD_IROUTER_SPI_MODE_ONE      (0U << 31)
> +#define GICD_IROUTER_SPI_MODE_ANY      (1U << 31)
> +
> +#define GIC_PIDR2_ARCH_MASK            0xf0
> +#define GIC_PIDR2_ARCH_GICv3           0x30
> +#define GIC_PIDR2_ARCH_GICv4           0x40
> +
> +/*
> + * Re-Distributor registers, offsets from RD_base
> + */
> +#define GICR_CTLR                      GICD_CTLR
> +#define GICR_IIDR                      0x0004
> +#define GICR_TYPER                     0x0008
> +#define GICR_STATUSR                   GICD_STATUSR
> +#define GICR_WAKER                     0x0014
> +#define GICR_SETLPIR                   0x0040
> +#define GICR_CLRLPIR                   0x0048
> +#define GICR_SEIR                      GICD_SEIR
> +#define GICR_PROPBASER                 0x0070
> +#define GICR_PENDBASER                 0x0078
> +#define GICR_INVLPIR                   0x00A0
> +#define GICR_INVALLR                   0x00B0
> +#define GICR_SYNCR                     0x00C0
> +#define GICR_MOVLPIR                   0x0100
> +#define GICR_MOVALLR                   0x0110
> +#define GICR_PIDR2                     GICD_PIDR2
> +
> +#define GICR_WAKER_ProcessorSleep      (1U << 1)
> +#define GICR_WAKER_ChildrenAsleep      (1U << 2)
> +
> +/*
> + * Re-Distributor registers, offsets from SGI_base
> + */
> +#define GICR_ISENABLER0                        GICD_ISENABLER
> +#define GICR_ICENABLER0                        GICD_ICENABLER
> +#define GICR_ISPENDR0                  GICD_ISPENDR
> +#define GICR_ICPENDR0                  GICD_ICPENDR
> +#define GICR_ISACTIVER0                        GICD_ISACTIVER
> +#define GICR_ICACTIVER0                        GICD_ICACTIVER
> +#define GICR_IPRIORITYR0               GICD_IPRIORITYR
> +#define GICR_ICFGR0                    GICD_ICFGR
> +
> +#define GICR_TYPER_VLPIS               (1U << 1)
> +#define GICR_TYPER_LAST                        (1U << 4)
> +
> +/*
> + * CPU interface registers
> + */
> +#define ICC_CTLR_EL1_EOImode_drop_dir  (0U << 1)
> +#define ICC_CTLR_EL1_EOImode_drop      (1U << 1)
> +#define ICC_SRE_EL1_SRE                        (1U << 0)
> +
> +/*
> + * Hypervisor interface registers (SRE only)
> + */
> +#define ICH_LR_VIRTUAL_ID_MASK         ((1UL << 32) - 1)
> +
> +#define ICH_LR_EOI                     (1UL << 41)
> +#define ICH_LR_GROUP                   (1UL << 60)
> +#define ICH_LR_STATE                   (3UL << 62)
> +#define ICH_LR_PENDING_BIT             (1UL << 62)
> +#define ICH_LR_ACTIVE_BIT              (1UL << 63)
> +
> +#define ICH_MISR_EOI                   (1 << 0)
> +#define ICH_MISR_U                     (1 << 1)
> +
> +#define ICH_HCR_EN                     (1 << 0)
> +#define ICH_HCR_UIE                    (1 << 1)
> +
> +#define ICH_VMCR_CTLR_SHIFT            0
> +#define ICH_VMCR_CTLR_MASK             (0x21f << ICH_VMCR_CTLR_SHIFT)
> +#define ICH_VMCR_BPR1_SHIFT            18
> +#define ICH_VMCR_BPR1_MASK             (7 << ICH_VMCR_BPR1_SHIFT)
> +#define ICH_VMCR_BPR0_SHIFT            21
> +#define ICH_VMCR_BPR0_MASK             (7 << ICH_VMCR_BPR0_SHIFT)
> +#define ICH_VMCR_PMR_SHIFT             24
> +#define ICH_VMCR_PMR_MASK              (0xffUL << ICH_VMCR_PMR_SHIFT)
> +
> +#define ICC_EOIR1_EL1                  S3_0_C12_C12_1
> +#define ICC_IAR1_EL1                   S3_0_C12_C12_0
> +#define ICC_SGI1R_EL1                  S3_0_C12_C11_5
> +#define ICC_PMR_EL1                    S3_0_C4_C6_0
> +#define ICC_CTLR_EL1                   S3_0_C12_C12_4
> +#define ICC_SRE_EL1                    S3_0_C12_C12_5
> +#define ICC_GRPEN1_EL1                 S3_0_C12_C12_7
> +
> +#define ICC_IAR1_EL1_SPURIOUS          0x3ff
> +
> +#define ICC_SRE_EL2                    S3_4_C12_C9_5
> +
> +#define ICC_SRE_EL2_SRE                        (1 << 0)
> +#define ICC_SRE_EL2_ENABLE             (1 << 3)
> +
> +/*
> + * System register definitions
> + */
> +#define ICH_VSEIR_EL2                  S3_4_C12_C9_4
> +#define ICH_HCR_EL2                    S3_4_C12_C11_0
> +#define ICH_VTR_EL2                    S3_4_C12_C11_1
> +#define ICH_MISR_EL2                   S3_4_C12_C11_2
> +#define ICH_EISR_EL2                   S3_4_C12_C11_3
> +#define ICH_ELSR_EL2                   S3_4_C12_C11_5
> +#define ICH_VMCR_EL2                   S3_4_C12_C11_7
> +
> +#define __LR0_EL2(x)                   S3_4_C12_C12_ ## x
> +#define __LR8_EL2(x)                   S3_4_C12_C13_ ## x
> +
> +#define ICH_LR0_EL2                    __LR0_EL2(0)
> +#define ICH_LR1_EL2                    __LR0_EL2(1)
> +#define ICH_LR2_EL2                    __LR0_EL2(2)
> +#define ICH_LR3_EL2                    __LR0_EL2(3)
> +#define ICH_LR4_EL2                    __LR0_EL2(4)
> +#define ICH_LR5_EL2                    __LR0_EL2(5)
> +#define ICH_LR6_EL2                    __LR0_EL2(6)
> +#define ICH_LR7_EL2                    __LR0_EL2(7)
> +#define ICH_LR8_EL2                    __LR8_EL2(0)
> +#define ICH_LR9_EL2                    __LR8_EL2(1)
> +#define ICH_LR10_EL2                   __LR8_EL2(2)
> +#define ICH_LR11_EL2                   __LR8_EL2(3)
> +#define ICH_LR12_EL2                   __LR8_EL2(4)
> +#define ICH_LR13_EL2                   __LR8_EL2(5)
> +#define ICH_LR14_EL2                   __LR8_EL2(6)
> +#define ICH_LR15_EL2                   __LR8_EL2(7)
> +
> +#define __AP0Rx_EL2(x)                 S3_4_C12_C8_ ## x
> +#define ICH_AP0R0_EL2                  __AP0Rx_EL2(0)
> +#define ICH_AP0R1_EL2                  __AP0Rx_EL2(1)
> +#define ICH_AP0R2_EL2                  __AP0Rx_EL2(2)
> +#define ICH_AP0R3_EL2                  __AP0Rx_EL2(3)
> +
> +#define __AP1Rx_EL2(x)                 S3_4_C12_C9_ ## x
> +#define ICH_AP1R0_EL2                  __AP1Rx_EL2(0)
> +#define ICH_AP1R1_EL2                  __AP1Rx_EL2(1)
> +#define ICH_AP1R2_EL2                  __AP1Rx_EL2(2)
> +#define ICH_AP1R3_EL2                  __AP1Rx_EL2(3)
> +
> +#ifndef __ASSEMBLY__
> +
> +#include <linux/stringify.h>
> +
> +static inline void gic_write_eoir(u64 irq)
> +{
> +       asm volatile("msr " __stringify(ICC_EOIR1_EL1) ", %0" : : "r" (irq));
> +       isb();
> +}
> +
> +#endif
> +
> +#endif
> --
> 2.0.0
>