linux/drivers/irqchip/irq-hip04.c
Arnd Bergmann 287980e49f remove lots of IS_ERR_VALUE abuses
Most users of IS_ERR_VALUE() in the kernel are wrong, as they
pass an 'int' into a function that takes an 'unsigned long'
argument. This happens to work because the type is sign-extended
on 64-bit architectures before it gets converted into an
unsigned type.

However, anything that passes an 'unsigned short' or 'unsigned int'
argument into IS_ERR_VALUE() is guaranteed to be broken, as are
8-bit integers and types that are wider than 'unsigned long'.

Andrzej Hajda has already fixed a lot of the worst abusers that
were causing actual bugs, but it would be nice to prevent any
users that are not passing 'unsigned long' arguments.

This patch changes all users of IS_ERR_VALUE() that I could find
on 32-bit ARM randconfig builds and x86 allmodconfig. For the
moment, this doesn't change the definition of IS_ERR_VALUE()
because there are probably still architecture specific users
elsewhere.

Almost all the warnings I got are for files that are better off
using 'if (err)' or 'if (err < 0)'.
The only legitimate user I could find that we get a warning for
is the (32-bit only) freescale fman driver, so I did not remove
the IS_ERR_VALUE() there but changed the type to 'unsigned long'.
For 9pfs, I just worked around one user whose calling conventions
are so obscure that I did not dare change the behavior.

I was using this definition for testing:

 #define IS_ERR_VALUE(x) ((unsigned long*)NULL == (typeof (x)*)NULL && \
       unlikely((unsigned long long)(x) >= (unsigned long long)(typeof(x))-MAX_ERRNO))

which ends up making all 16-bit or wider types work correctly with
the most plausible interpretation of what IS_ERR_VALUE() was supposed
to return according to its users, but also causes a compile-time
warning for any users that do not pass an 'unsigned long' argument.

I suggested this approach earlier this year, but back then we ended
up deciding to just fix the users that are obviously broken. After
the initial warning that caused me to get involved in the discussion
(fs/gfs2/dir.c) showed up again in the mainline kernel, Linus
asked me to send the whole thing again.

[ Updated the 9p parts as per Al Viro  - Linus ]

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Cc: Andrzej Hajda <a.hajda@samsung.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Link: https://lkml.org/lkml/2016/1/7/363
Link: https://lkml.org/lkml/2016/5/27/486
Acked-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org> # For nvmem part
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-05-27 15:26:11 -07:00

430 lines
11 KiB
C

/*
* Hisilicon HiP04 INTC
*
* Copyright (C) 2002-2014 ARM Limited.
* Copyright (c) 2013-2014 Hisilicon Ltd.
* Copyright (c) 2013-2014 Linaro Ltd.
*
* 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.
*
* Interrupt architecture for the HIP04 INTC:
*
* o There is one Interrupt Distributor, which receives interrupts
* from system devices and sends them to the Interrupt Controllers.
*
* o There is one CPU Interface per CPU, which sends interrupts sent
* by the Distributor, and interrupts generated locally, to the
* associated CPU. The base address of the CPU interface is usually
* aliased so that the same address points to different chips depending
* on the CPU it is accessed from.
*
* Note that IRQs 0-31 are special - they are local to each CPU.
* As such, the enable set/clear, pending set/clear and active bit
* registers are banked per-cpu for these sources.
*/
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/err.h>
#include <linux/module.h>
#include <linux/list.h>
#include <linux/smp.h>
#include <linux/cpu.h>
#include <linux/cpu_pm.h>
#include <linux/cpumask.h>
#include <linux/io.h>
#include <linux/of.h>
#include <linux/of_address.h>
#include <linux/of_irq.h>
#include <linux/irqdomain.h>
#include <linux/interrupt.h>
#include <linux/slab.h>
#include <linux/irqchip.h>
#include <linux/irqchip/arm-gic.h>
#include <asm/irq.h>
#include <asm/exception.h>
#include <asm/smp_plat.h>
#include "irq-gic-common.h"
#define HIP04_MAX_IRQS 510
struct hip04_irq_data {
void __iomem *dist_base;
void __iomem *cpu_base;
struct irq_domain *domain;
unsigned int nr_irqs;
};
static DEFINE_RAW_SPINLOCK(irq_controller_lock);
/*
* The GIC mapping of CPU interfaces does not necessarily match
* the logical CPU numbering. Let's use a mapping as returned
* by the GIC itself.
*/
#define NR_HIP04_CPU_IF 16
static u16 hip04_cpu_map[NR_HIP04_CPU_IF] __read_mostly;
static struct hip04_irq_data hip04_data __read_mostly;
static inline void __iomem *hip04_dist_base(struct irq_data *d)
{
struct hip04_irq_data *hip04_data = irq_data_get_irq_chip_data(d);
return hip04_data->dist_base;
}
static inline void __iomem *hip04_cpu_base(struct irq_data *d)
{
struct hip04_irq_data *hip04_data = irq_data_get_irq_chip_data(d);
return hip04_data->cpu_base;
}
static inline unsigned int hip04_irq(struct irq_data *d)
{
return d->hwirq;
}
/*
* Routines to acknowledge, disable and enable interrupts
*/
static void hip04_mask_irq(struct irq_data *d)
{
u32 mask = 1 << (hip04_irq(d) % 32);
raw_spin_lock(&irq_controller_lock);
writel_relaxed(mask, hip04_dist_base(d) + GIC_DIST_ENABLE_CLEAR +
(hip04_irq(d) / 32) * 4);
raw_spin_unlock(&irq_controller_lock);
}
static void hip04_unmask_irq(struct irq_data *d)
{
u32 mask = 1 << (hip04_irq(d) % 32);
raw_spin_lock(&irq_controller_lock);
writel_relaxed(mask, hip04_dist_base(d) + GIC_DIST_ENABLE_SET +
(hip04_irq(d) / 32) * 4);
raw_spin_unlock(&irq_controller_lock);
}
static void hip04_eoi_irq(struct irq_data *d)
{
writel_relaxed(hip04_irq(d), hip04_cpu_base(d) + GIC_CPU_EOI);
}
static int hip04_irq_set_type(struct irq_data *d, unsigned int type)
{
void __iomem *base = hip04_dist_base(d);
unsigned int irq = hip04_irq(d);
int ret;
/* Interrupt configuration for SGIs can't be changed */
if (irq < 16)
return -EINVAL;
/* SPIs have restrictions on the supported types */
if (irq >= 32 && type != IRQ_TYPE_LEVEL_HIGH &&
type != IRQ_TYPE_EDGE_RISING)
return -EINVAL;
raw_spin_lock(&irq_controller_lock);
ret = gic_configure_irq(irq, type, base, NULL);
raw_spin_unlock(&irq_controller_lock);
return ret;
}
#ifdef CONFIG_SMP
static int hip04_irq_set_affinity(struct irq_data *d,
const struct cpumask *mask_val,
bool force)
{
void __iomem *reg;
unsigned int cpu, shift = (hip04_irq(d) % 2) * 16;
u32 val, mask, bit;
if (!force)
cpu = cpumask_any_and(mask_val, cpu_online_mask);
else
cpu = cpumask_first(mask_val);
if (cpu >= NR_HIP04_CPU_IF || cpu >= nr_cpu_ids)
return -EINVAL;
raw_spin_lock(&irq_controller_lock);
reg = hip04_dist_base(d) + GIC_DIST_TARGET + ((hip04_irq(d) * 2) & ~3);
mask = 0xffff << shift;
bit = hip04_cpu_map[cpu] << shift;
val = readl_relaxed(reg) & ~mask;
writel_relaxed(val | bit, reg);
raw_spin_unlock(&irq_controller_lock);
return IRQ_SET_MASK_OK;
}
#endif
static void __exception_irq_entry hip04_handle_irq(struct pt_regs *regs)
{
u32 irqstat, irqnr;
void __iomem *cpu_base = hip04_data.cpu_base;
do {
irqstat = readl_relaxed(cpu_base + GIC_CPU_INTACK);
irqnr = irqstat & GICC_IAR_INT_ID_MASK;
if (likely(irqnr > 15 && irqnr <= HIP04_MAX_IRQS)) {
handle_domain_irq(hip04_data.domain, irqnr, regs);
continue;
}
if (irqnr < 16) {
writel_relaxed(irqstat, cpu_base + GIC_CPU_EOI);
#ifdef CONFIG_SMP
handle_IPI(irqnr, regs);
#endif
continue;
}
break;
} while (1);
}
static struct irq_chip hip04_irq_chip = {
.name = "HIP04 INTC",
.irq_mask = hip04_mask_irq,
.irq_unmask = hip04_unmask_irq,
.irq_eoi = hip04_eoi_irq,
.irq_set_type = hip04_irq_set_type,
#ifdef CONFIG_SMP
.irq_set_affinity = hip04_irq_set_affinity,
#endif
.flags = IRQCHIP_SET_TYPE_MASKED |
IRQCHIP_SKIP_SET_WAKE |
IRQCHIP_MASK_ON_SUSPEND,
};
static u16 hip04_get_cpumask(struct hip04_irq_data *intc)
{
void __iomem *base = intc->dist_base;
u32 mask, i;
for (i = mask = 0; i < 32; i += 2) {
mask = readl_relaxed(base + GIC_DIST_TARGET + i * 2);
mask |= mask >> 16;
if (mask)
break;
}
if (!mask)
pr_crit("GIC CPU mask not found - kernel will fail to boot.\n");
return mask;
}
static void __init hip04_irq_dist_init(struct hip04_irq_data *intc)
{
unsigned int i;
u32 cpumask;
unsigned int nr_irqs = intc->nr_irqs;
void __iomem *base = intc->dist_base;
writel_relaxed(0, base + GIC_DIST_CTRL);
/*
* Set all global interrupts to this CPU only.
*/
cpumask = hip04_get_cpumask(intc);
cpumask |= cpumask << 16;
for (i = 32; i < nr_irqs; i += 2)
writel_relaxed(cpumask, base + GIC_DIST_TARGET + ((i * 2) & ~3));
gic_dist_config(base, nr_irqs, NULL);
writel_relaxed(1, base + GIC_DIST_CTRL);
}
static void hip04_irq_cpu_init(struct hip04_irq_data *intc)
{
void __iomem *dist_base = intc->dist_base;
void __iomem *base = intc->cpu_base;
unsigned int cpu_mask, cpu = smp_processor_id();
int i;
/*
* Get what the GIC says our CPU mask is.
*/
BUG_ON(cpu >= NR_HIP04_CPU_IF);
cpu_mask = hip04_get_cpumask(intc);
hip04_cpu_map[cpu] = cpu_mask;
/*
* Clear our mask from the other map entries in case they're
* still undefined.
*/
for (i = 0; i < NR_HIP04_CPU_IF; i++)
if (i != cpu)
hip04_cpu_map[i] &= ~cpu_mask;
gic_cpu_config(dist_base, NULL);
writel_relaxed(0xf0, base + GIC_CPU_PRIMASK);
writel_relaxed(1, base + GIC_CPU_CTRL);
}
#ifdef CONFIG_SMP
static void hip04_raise_softirq(const struct cpumask *mask, unsigned int irq)
{
int cpu;
unsigned long flags, map = 0;
raw_spin_lock_irqsave(&irq_controller_lock, flags);
/* Convert our logical CPU mask into a physical one. */
for_each_cpu(cpu, mask)
map |= hip04_cpu_map[cpu];
/*
* Ensure that stores to Normal memory are visible to the
* other CPUs before they observe us issuing the IPI.
*/
dmb(ishst);
/* this always happens on GIC0 */
writel_relaxed(map << 8 | irq, hip04_data.dist_base + GIC_DIST_SOFTINT);
raw_spin_unlock_irqrestore(&irq_controller_lock, flags);
}
#endif
static int hip04_irq_domain_map(struct irq_domain *d, unsigned int irq,
irq_hw_number_t hw)
{
if (hw < 32) {
irq_set_percpu_devid(irq);
irq_set_chip_and_handler(irq, &hip04_irq_chip,
handle_percpu_devid_irq);
irq_set_status_flags(irq, IRQ_NOAUTOEN);
} else {
irq_set_chip_and_handler(irq, &hip04_irq_chip,
handle_fasteoi_irq);
irq_set_probe(irq);
}
irq_set_chip_data(irq, d->host_data);
return 0;
}
static int hip04_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)
{
unsigned long ret = 0;
if (irq_domain_get_of_node(d) != controller)
return -EINVAL;
if (intsize < 3)
return -EINVAL;
/* Get the interrupt number and add 16 to skip over SGIs */
*out_hwirq = intspec[1] + 16;
/* For SPIs, we need to add 16 more to get the irq ID number */
if (!intspec[0])
*out_hwirq += 16;
*out_type = intspec[2] & IRQ_TYPE_SENSE_MASK;
return ret;
}
#ifdef CONFIG_SMP
static int hip04_irq_secondary_init(struct notifier_block *nfb,
unsigned long action,
void *hcpu)
{
if (action == CPU_STARTING || action == CPU_STARTING_FROZEN)
hip04_irq_cpu_init(&hip04_data);
return NOTIFY_OK;
}
/*
* Notifier for enabling the INTC CPU interface. Set an arbitrarily high
* priority because the GIC needs to be up before the ARM generic timers.
*/
static struct notifier_block hip04_irq_cpu_notifier = {
.notifier_call = hip04_irq_secondary_init,
.priority = 100,
};
#endif
static const struct irq_domain_ops hip04_irq_domain_ops = {
.map = hip04_irq_domain_map,
.xlate = hip04_irq_domain_xlate,
};
static int __init
hip04_of_init(struct device_node *node, struct device_node *parent)
{
irq_hw_number_t hwirq_base = 16;
int nr_irqs, irq_base, i;
if (WARN_ON(!node))
return -ENODEV;
hip04_data.dist_base = of_iomap(node, 0);
WARN(!hip04_data.dist_base, "fail to map hip04 intc dist registers\n");
hip04_data.cpu_base = of_iomap(node, 1);
WARN(!hip04_data.cpu_base, "unable to map hip04 intc cpu registers\n");
/*
* Initialize the CPU interface map to all CPUs.
* It will be refined as each CPU probes its ID.
*/
for (i = 0; i < NR_HIP04_CPU_IF; i++)
hip04_cpu_map[i] = 0xffff;
/*
* Find out how many interrupts are supported.
* The HIP04 INTC only supports up to 510 interrupt sources.
*/
nr_irqs = readl_relaxed(hip04_data.dist_base + GIC_DIST_CTR) & 0x1f;
nr_irqs = (nr_irqs + 1) * 32;
if (nr_irqs > HIP04_MAX_IRQS)
nr_irqs = HIP04_MAX_IRQS;
hip04_data.nr_irqs = nr_irqs;
nr_irqs -= hwirq_base; /* calculate # of irqs to allocate */
irq_base = irq_alloc_descs(-1, hwirq_base, nr_irqs, numa_node_id());
if (irq_base < 0) {
pr_err("failed to allocate IRQ numbers\n");
return -EINVAL;
}
hip04_data.domain = irq_domain_add_legacy(node, nr_irqs, irq_base,
hwirq_base,
&hip04_irq_domain_ops,
&hip04_data);
if (WARN_ON(!hip04_data.domain))
return -EINVAL;
#ifdef CONFIG_SMP
set_smp_cross_call(hip04_raise_softirq);
register_cpu_notifier(&hip04_irq_cpu_notifier);
#endif
set_handle_irq(hip04_handle_irq);
hip04_irq_dist_init(&hip04_data);
hip04_irq_cpu_init(&hip04_data);
return 0;
}
IRQCHIP_DECLARE(hip04_intc, "hisilicon,hip04-intc", hip04_of_init);