/*
* Copyright (C) 2013, 2014 ARM Limited, All Rights Reserved.
* Author: Marc Zyngier <[email protected]>
*
* 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/cpu_pm.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 redist_region {
void __iomem *redist_base;
phys_addr_t phys_base;
};
struct gic_chip_data {
void __iomem *dist_base;
struct redist_region *redist_regions;
struct rdists rdists;
struct irq_domain *domain;
u64 redist_stride;
u32 nr_redist_regions;
unsigned int irq_nr;
};
static struct gic_chip_data gic_data __read_mostly;
#define gic_data_rdist() (this_cpu_ptr(gic_data.rdists.rdist))
#define gic_data_rdist_rd_base() (gic_data_rdist()->rd_base)
#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;
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 __maybe_unused gic_read_iar(void)
{
u64 irqstat;
asm volatile("mrs_s %0, " __stringify(ICC_IAR1_EL1) : "=r" (irqstat));
return irqstat;
}
static void __maybe_unused gic_write_pmr(u64 val)
{
asm volatile("msr_s " __stringify(ICC_PMR_EL1) ", %0" : : "r" (val));
}
static void __maybe_unused gic_write_ctlr(u64 val)
{
asm volatile("msr_s " __stringify(ICC_CTLR_EL1) ", %0" : : "r" (val));
isb();
}
static void __maybe_unused gic_write_grpen1(u64 val)
{
asm volatile("msr_s " __stringify(ICC_GRPEN1_EL1) ", %0" : : "r" (val));
isb();
}
static void __maybe_unused gic_write_sgi1r(u64 val)
{
asm volatile("msr_s " __stringify(ICC_SGI1R_EL1) ", %0" : : "r" (val));
}
static void gic_enable_sre(void)
{
u64 val;
asm volatile("mrs_s %0, " __stringify(ICC_SRE_EL1) : "=r" (val));
val |= ICC_SRE_EL1_SRE;
asm volatile("msr_s " __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_s %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(bool enable)
{
void __iomem *rbase;
u32 count = 1000000; /* 1s! */
u32 val;
rbase = gic_data_rdist_rd_base();
val = readl_relaxed(rbase + GICR_WAKER);
if (enable)
/* Wake up this CPU redistributor */
val &= ~GICR_WAKER_ProcessorSleep;
else
val |= GICR_WAKER_ProcessorSleep;
writel_relaxed(val, rbase + GICR_WAKER);
if (!enable) { /* Check that GICR_WAKER is writeable */
val = readl_relaxed(rbase + GICR_WAKER);
if (!(val & GICR_WAKER_ProcessorSleep))
return; /* No PM support in this redistributor */
}
while (count--) {
val = readl_relaxed(rbase + GICR_WAKER);
if (enable ^ (val & GICR_WAKER_ChildrenAsleep))
break;
cpu_relax();
udelay(1);
};
if (!count)
pr_err_ratelimited("redistributor failed to %s...\n",
enable ? "wakeup" : "sleep");
}
/*
* 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 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) || irqnr >= 8192) {
int err;
err = handle_domain_irq(gic_data.domain, irqnr, regs);
if (err) {
WARN_ONCE(true, "Unexpected interrupt received!\n");
gic_write_eoir(irqnr);
}
continue;
}
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(mpid