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linux-next/drivers/irqchip/irq-clps711x.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

239 lines
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/*
* CLPS711X IRQ driver
*
* Copyright (C) 2013 Alexander Shiyan <shc_work@mail.ru>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*/
#include <linux/io.h>
#include <linux/irq.h>
#include <linux/irqchip.h>
#include <linux/irqdomain.h>
#include <linux/of_address.h>
#include <linux/of_irq.h>
#include <linux/slab.h>
#include <asm/exception.h>
#include <asm/mach/irq.h>
#define CLPS711X_INTSR1 (0x0240)
#define CLPS711X_INTMR1 (0x0280)
#define CLPS711X_BLEOI (0x0600)
#define CLPS711X_MCEOI (0x0640)
#define CLPS711X_TEOI (0x0680)
#define CLPS711X_TC1EOI (0x06c0)
#define CLPS711X_TC2EOI (0x0700)
#define CLPS711X_RTCEOI (0x0740)
#define CLPS711X_UMSEOI (0x0780)
#define CLPS711X_COEOI (0x07c0)
#define CLPS711X_INTSR2 (0x1240)
#define CLPS711X_INTMR2 (0x1280)
#define CLPS711X_SRXEOF (0x1600)
#define CLPS711X_KBDEOI (0x1700)
#define CLPS711X_INTSR3 (0x2240)
#define CLPS711X_INTMR3 (0x2280)
static const struct {
#define CLPS711X_FLAG_EN (1 << 0)
#define CLPS711X_FLAG_FIQ (1 << 1)
unsigned int flags;
phys_addr_t eoi;
} clps711x_irqs[] = {
[1] = { CLPS711X_FLAG_FIQ, CLPS711X_BLEOI, },
[3] = { CLPS711X_FLAG_FIQ, CLPS711X_MCEOI, },
[4] = { CLPS711X_FLAG_EN, CLPS711X_COEOI, },
[5] = { CLPS711X_FLAG_EN, },
[6] = { CLPS711X_FLAG_EN, },
[7] = { CLPS711X_FLAG_EN, },
[8] = { CLPS711X_FLAG_EN, CLPS711X_TC1EOI, },
[9] = { CLPS711X_FLAG_EN, CLPS711X_TC2EOI, },
[10] = { CLPS711X_FLAG_EN, CLPS711X_RTCEOI, },
[11] = { CLPS711X_FLAG_EN, CLPS711X_TEOI, },
[12] = { CLPS711X_FLAG_EN, },
[13] = { CLPS711X_FLAG_EN, },
[14] = { CLPS711X_FLAG_EN, CLPS711X_UMSEOI, },
[15] = { CLPS711X_FLAG_EN, CLPS711X_SRXEOF, },
[16] = { CLPS711X_FLAG_EN, CLPS711X_KBDEOI, },
[17] = { CLPS711X_FLAG_EN, },
[18] = { CLPS711X_FLAG_EN, },
[28] = { CLPS711X_FLAG_EN, },
[29] = { CLPS711X_FLAG_EN, },
[32] = { CLPS711X_FLAG_FIQ, },
};
static struct {
void __iomem *base;
void __iomem *intmr[3];
void __iomem *intsr[3];
struct irq_domain *domain;
struct irq_domain_ops ops;
} *clps711x_intc;
static asmlinkage void __exception_irq_entry clps711x_irqh(struct pt_regs *regs)
{
u32 irqstat;
do {
irqstat = readw_relaxed(clps711x_intc->intmr[0]) &
readw_relaxed(clps711x_intc->intsr[0]);
if (irqstat)
handle_domain_irq(clps711x_intc->domain,
fls(irqstat) - 1, regs);
irqstat = readw_relaxed(clps711x_intc->intmr[1]) &
readw_relaxed(clps711x_intc->intsr[1]);
if (irqstat)
handle_domain_irq(clps711x_intc->domain,
fls(irqstat) - 1 + 16, regs);
} while (irqstat);
}
static void clps711x_intc_eoi(struct irq_data *d)
{
irq_hw_number_t hwirq = irqd_to_hwirq(d);
writel_relaxed(0, clps711x_intc->base + clps711x_irqs[hwirq].eoi);
}
static void clps711x_intc_mask(struct irq_data *d)
{
irq_hw_number_t hwirq = irqd_to_hwirq(d);
void __iomem *intmr = clps711x_intc->intmr[hwirq / 16];
u32 tmp;
tmp = readl_relaxed(intmr);
tmp &= ~(1 << (hwirq % 16));
writel_relaxed(tmp, intmr);
}
static void clps711x_intc_unmask(struct irq_data *d)
{
irq_hw_number_t hwirq = irqd_to_hwirq(d);
void __iomem *intmr = clps711x_intc->intmr[hwirq / 16];
u32 tmp;
tmp = readl_relaxed(intmr);
tmp |= 1 << (hwirq % 16);
writel_relaxed(tmp, intmr);
}
static struct irq_chip clps711x_intc_chip = {
.name = "clps711x-intc",
.irq_eoi = clps711x_intc_eoi,
.irq_mask = clps711x_intc_mask,
.irq_unmask = clps711x_intc_unmask,
};
static int __init clps711x_intc_irq_map(struct irq_domain *h, unsigned int virq,
irq_hw_number_t hw)
{
irq_flow_handler_t handler = handle_level_irq;
unsigned int flags = 0;
if (!clps711x_irqs[hw].flags)
return 0;
if (clps711x_irqs[hw].flags & CLPS711X_FLAG_FIQ) {
handler = handle_bad_irq;
flags |= IRQ_NOAUTOEN;
} else if (clps711x_irqs[hw].eoi) {
handler = handle_fasteoi_irq;
}
/* Clear down pending interrupt */
if (clps711x_irqs[hw].eoi)
writel_relaxed(0, clps711x_intc->base + clps711x_irqs[hw].eoi);
irq_set_chip_and_handler(virq, &clps711x_intc_chip, handler);
irq_modify_status(virq, IRQ_NOPROBE, flags);
return 0;
}
static int __init _clps711x_intc_init(struct device_node *np,
phys_addr_t base, resource_size_t size)
{
int err;
clps711x_intc = kzalloc(sizeof(*clps711x_intc), GFP_KERNEL);
if (!clps711x_intc)
return -ENOMEM;
clps711x_intc->base = ioremap(base, size);
if (!clps711x_intc->base) {
err = -ENOMEM;
goto out_kfree;
}
clps711x_intc->intsr[0] = clps711x_intc->base + CLPS711X_INTSR1;
clps711x_intc->intmr[0] = clps711x_intc->base + CLPS711X_INTMR1;
clps711x_intc->intsr[1] = clps711x_intc->base + CLPS711X_INTSR2;
clps711x_intc->intmr[1] = clps711x_intc->base + CLPS711X_INTMR2;
clps711x_intc->intsr[2] = clps711x_intc->base + CLPS711X_INTSR3;
clps711x_intc->intmr[2] = clps711x_intc->base + CLPS711X_INTMR3;
/* Mask all interrupts */
writel_relaxed(0, clps711x_intc->intmr[0]);
writel_relaxed(0, clps711x_intc->intmr[1]);
writel_relaxed(0, clps711x_intc->intmr[2]);
err = irq_alloc_descs(-1, 0, ARRAY_SIZE(clps711x_irqs), numa_node_id());
if (err < 0)
goto out_iounmap;
clps711x_intc->ops.map = clps711x_intc_irq_map;
clps711x_intc->ops.xlate = irq_domain_xlate_onecell;
clps711x_intc->domain =
irq_domain_add_legacy(np, ARRAY_SIZE(clps711x_irqs),
0, 0, &clps711x_intc->ops, NULL);
if (!clps711x_intc->domain) {
err = -ENOMEM;
goto out_irqfree;
}
irq_set_default_host(clps711x_intc->domain);
set_handle_irq(clps711x_irqh);
#ifdef CONFIG_FIQ
init_FIQ(0);
#endif
return 0;
out_irqfree:
irq_free_descs(0, ARRAY_SIZE(clps711x_irqs));
out_iounmap:
iounmap(clps711x_intc->base);
out_kfree:
kfree(clps711x_intc);
return err;
}
void __init clps711x_intc_init(phys_addr_t base, resource_size_t size)
{
BUG_ON(_clps711x_intc_init(NULL, base, size));
}
#ifdef CONFIG_IRQCHIP
static int __init clps711x_intc_init_dt(struct device_node *np,
struct device_node *parent)
{
struct resource res;
int err;
err = of_address_to_resource(np, 0, &res);
if (err)
return err;
return _clps711x_intc_init(np, res.start, resource_size(&res));
}
IRQCHIP_DECLARE(clps711x, "cirrus,clps711x-intc", clps711x_intc_init_dt);
#endif
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