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kernel-ark/drivers/bus/brcmstb_gisb.c
Florian Fainelli c400d5ebec BUS: brcmstb_gisb: Hook to MIPS board_be_handler 
MIPS kernels allow platforms to invoke a custom Bus Error handler, add the
necessary code to do this for Broadcom SoCs where the GISB bus error handler can be used.

We may get a bus error from an address decoded outside of the GISB bus space,
so we need to check the validity of such a capture before printing anything.

Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Cc: cernekee@gmail.com
Cc: arnd@arndb.de
Cc: jaedon.shin@gmail.com
Cc: pgynther@google.com
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/12284/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2016-05-13 14:01:55 +02:00

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/*
* Copyright (C) 2014 Broadcom Corporation
*
* 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.
*/
#include <linux/init.h>
#include <linux/types.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/interrupt.h>
#include <linux/sysfs.h>
#include <linux/io.h>
#include <linux/string.h>
#include <linux/device.h>
#include <linux/list.h>
#include <linux/of.h>
#include <linux/bitops.h>
#include <linux/pm.h>
#ifdef CONFIG_ARM
#include <asm/bug.h>
#include <asm/signal.h>
#endif
#ifdef CONFIG_MIPS
#include <asm/traps.h>
#endif
#define ARB_ERR_CAP_CLEAR (1 << 0)
#define ARB_ERR_CAP_STATUS_TIMEOUT (1 << 12)
#define ARB_ERR_CAP_STATUS_TEA (1 << 11)
#define ARB_ERR_CAP_STATUS_BS_SHIFT (1 << 2)
#define ARB_ERR_CAP_STATUS_BS_MASK 0x3c
#define ARB_ERR_CAP_STATUS_WRITE (1 << 1)
#define ARB_ERR_CAP_STATUS_VALID (1 << 0)
enum {
ARB_TIMER,
ARB_ERR_CAP_CLR,
ARB_ERR_CAP_HI_ADDR,
ARB_ERR_CAP_ADDR,
ARB_ERR_CAP_DATA,
ARB_ERR_CAP_STATUS,
ARB_ERR_CAP_MASTER,
};
static const int gisb_offsets_bcm7038[] = {
[ARB_TIMER] = 0x00c,
[ARB_ERR_CAP_CLR] = 0x0c4,
[ARB_ERR_CAP_HI_ADDR] = -1,
[ARB_ERR_CAP_ADDR] = 0x0c8,
[ARB_ERR_CAP_DATA] = 0x0cc,
[ARB_ERR_CAP_STATUS] = 0x0d0,
[ARB_ERR_CAP_MASTER] = -1,
};
static const int gisb_offsets_bcm7400[] = {
[ARB_TIMER] = 0x00c,
[ARB_ERR_CAP_CLR] = 0x0c8,
[ARB_ERR_CAP_HI_ADDR] = -1,
[ARB_ERR_CAP_ADDR] = 0x0cc,
[ARB_ERR_CAP_DATA] = 0x0d0,
[ARB_ERR_CAP_STATUS] = 0x0d4,
[ARB_ERR_CAP_MASTER] = 0x0d8,
};
static const int gisb_offsets_bcm7435[] = {
[ARB_TIMER] = 0x00c,
[ARB_ERR_CAP_CLR] = 0x168,
[ARB_ERR_CAP_HI_ADDR] = -1,
[ARB_ERR_CAP_ADDR] = 0x16c,
[ARB_ERR_CAP_DATA] = 0x170,
[ARB_ERR_CAP_STATUS] = 0x174,
[ARB_ERR_CAP_MASTER] = 0x178,
};
static const int gisb_offsets_bcm7445[] = {
[ARB_TIMER] = 0x008,
[ARB_ERR_CAP_CLR] = 0x7e4,
[ARB_ERR_CAP_HI_ADDR] = 0x7e8,
[ARB_ERR_CAP_ADDR] = 0x7ec,
[ARB_ERR_CAP_DATA] = 0x7f0,
[ARB_ERR_CAP_STATUS] = 0x7f4,
[ARB_ERR_CAP_MASTER] = 0x7f8,
};
struct brcmstb_gisb_arb_device {
void __iomem *base;
const int *gisb_offsets;
bool big_endian;
struct mutex lock;
struct list_head next;
u32 valid_mask;
const char *master_names[sizeof(u32) * BITS_PER_BYTE];
u32 saved_timeout;
};
static LIST_HEAD(brcmstb_gisb_arb_device_list);
static u32 gisb_read(struct brcmstb_gisb_arb_device *gdev, int reg)
{
int offset = gdev->gisb_offsets[reg];
/* return 1 if the hardware doesn't have ARB_ERR_CAP_MASTER */
if (offset == -1)
return 1;
if (gdev->big_endian)
return ioread32be(gdev->base + offset);
else
return ioread32(gdev->base + offset);
}
static void gisb_write(struct brcmstb_gisb_arb_device *gdev, u32 val, int reg)
{
int offset = gdev->gisb_offsets[reg];
if (offset == -1)
return;
if (gdev->big_endian)
iowrite32be(val, gdev->base + reg);
else
iowrite32(val, gdev->base + reg);
}
static ssize_t gisb_arb_get_timeout(struct device *dev,
struct device_attribute *attr,
char *buf)
{
struct platform_device *pdev = to_platform_device(dev);
struct brcmstb_gisb_arb_device *gdev = platform_get_drvdata(pdev);
u32 timeout;
mutex_lock(&gdev->lock);
timeout = gisb_read(gdev, ARB_TIMER);
mutex_unlock(&gdev->lock);
return sprintf(buf, "%d", timeout);
}
static ssize_t gisb_arb_set_timeout(struct device *dev,
struct device_attribute *attr,
const char *buf, size_t count)
{
struct platform_device *pdev = to_platform_device(dev);
struct brcmstb_gisb_arb_device *gdev = platform_get_drvdata(pdev);
int val, ret;
ret = kstrtoint(buf, 10, &val);
if (ret < 0)
return ret;
if (val == 0 || val >= 0xffffffff)
return -EINVAL;
mutex_lock(&gdev->lock);
gisb_write(gdev, val, ARB_TIMER);
mutex_unlock(&gdev->lock);
return count;
}
static const char *
brcmstb_gisb_master_to_str(struct brcmstb_gisb_arb_device *gdev,
u32 masters)
{
u32 mask = gdev->valid_mask & masters;
if (hweight_long(mask) != 1)
return NULL;
return gdev->master_names[ffs(mask) - 1];
}
static int brcmstb_gisb_arb_decode_addr(struct brcmstb_gisb_arb_device *gdev,
const char *reason)
{
u32 cap_status;
unsigned long arb_addr;
u32 master;
const char *m_name;
char m_fmt[11];
cap_status = gisb_read(gdev, ARB_ERR_CAP_STATUS);
/* Invalid captured address, bail out */
if (!(cap_status & ARB_ERR_CAP_STATUS_VALID))
return 1;
/* Read the address and master */
arb_addr = gisb_read(gdev, ARB_ERR_CAP_ADDR) & 0xffffffff;
#if (IS_ENABLED(CONFIG_PHYS_ADDR_T_64BIT))
arb_addr |= (u64)gisb_read(gdev, ARB_ERR_CAP_HI_ADDR) << 32;
#endif
master = gisb_read(gdev, ARB_ERR_CAP_MASTER);
m_name = brcmstb_gisb_master_to_str(gdev, master);
if (!m_name) {
snprintf(m_fmt, sizeof(m_fmt), "0x%08x", master);
m_name = m_fmt;
}
pr_crit("%s: %s at 0x%lx [%c %s], core: %s\n",
__func__, reason, arb_addr,
cap_status & ARB_ERR_CAP_STATUS_WRITE ? 'W' : 'R',
cap_status & ARB_ERR_CAP_STATUS_TIMEOUT ? "timeout" : "",
m_name);
/* clear the GISB error */
gisb_write(gdev, ARB_ERR_CAP_CLEAR, ARB_ERR_CAP_CLR);
return 0;
}
#ifdef CONFIG_ARM
static int brcmstb_bus_error_handler(unsigned long addr, unsigned int fsr,
struct pt_regs *regs)
{
int ret = 0;
struct brcmstb_gisb_arb_device *gdev;
/* iterate over each GISB arb registered handlers */
list_for_each_entry(gdev, &brcmstb_gisb_arb_device_list, next)
ret |= brcmstb_gisb_arb_decode_addr(gdev, "bus error");
/*
* If it was an imprecise abort, then we need to correct the
* return address to be _after_ the instruction.
*/
if (fsr & (1 << 10))
regs->ARM_pc += 4;
return ret;
}
#endif
#ifdef CONFIG_MIPS
static int brcmstb_bus_error_handler(struct pt_regs *regs, int is_fixup)
{
int ret = 0;
struct brcmstb_gisb_arb_device *gdev;
u32 cap_status;
list_for_each_entry(gdev, &brcmstb_gisb_arb_device_list, next) {
cap_status = gisb_read(gdev, ARB_ERR_CAP_STATUS);
/* Invalid captured address, bail out */
if (!(cap_status & ARB_ERR_CAP_STATUS_VALID)) {
is_fixup = 1;
goto out;
}
ret |= brcmstb_gisb_arb_decode_addr(gdev, "bus error");
}
out:
return is_fixup ? MIPS_BE_FIXUP : MIPS_BE_FATAL;
}
#endif
static irqreturn_t brcmstb_gisb_timeout_handler(int irq, void *dev_id)
{
brcmstb_gisb_arb_decode_addr(dev_id, "timeout");
return IRQ_HANDLED;
}
static irqreturn_t brcmstb_gisb_tea_handler(int irq, void *dev_id)
{
brcmstb_gisb_arb_decode_addr(dev_id, "target abort");
return IRQ_HANDLED;
}
static DEVICE_ATTR(gisb_arb_timeout, S_IWUSR | S_IRUGO,
gisb_arb_get_timeout, gisb_arb_set_timeout);
static struct attribute *gisb_arb_sysfs_attrs[] = {
&dev_attr_gisb_arb_timeout.attr,
NULL,
};
static struct attribute_group gisb_arb_sysfs_attr_group = {
.attrs = gisb_arb_sysfs_attrs,
};
static const struct of_device_id brcmstb_gisb_arb_of_match[] = {
{ .compatible = "brcm,gisb-arb", .data = gisb_offsets_bcm7445 },
{ .compatible = "brcm,bcm7445-gisb-arb", .data = gisb_offsets_bcm7445 },
{ .compatible = "brcm,bcm7435-gisb-arb", .data = gisb_offsets_bcm7435 },
{ .compatible = "brcm,bcm7400-gisb-arb", .data = gisb_offsets_bcm7400 },
{ .compatible = "brcm,bcm7038-gisb-arb", .data = gisb_offsets_bcm7038 },
{ },
};
static int __init brcmstb_gisb_arb_probe(struct platform_device *pdev)
{
struct device_node *dn = pdev->dev.of_node;
struct brcmstb_gisb_arb_device *gdev;
const struct of_device_id *of_id;
struct resource *r;
int err, timeout_irq, tea_irq;
unsigned int num_masters, j = 0;
int i, first, last;
r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
timeout_irq = platform_get_irq(pdev, 0);
tea_irq = platform_get_irq(pdev, 1);
gdev = devm_kzalloc(&pdev->dev, sizeof(*gdev), GFP_KERNEL);
if (!gdev)
return -ENOMEM;
mutex_init(&gdev->lock);
INIT_LIST_HEAD(&gdev->next);
gdev->base = devm_ioremap_resource(&pdev->dev, r);
if (IS_ERR(gdev->base))
return PTR_ERR(gdev->base);
of_id = of_match_node(brcmstb_gisb_arb_of_match, dn);
if (!of_id) {
pr_err("failed to look up compatible string\n");
return -EINVAL;
}
gdev->gisb_offsets = of_id->data;
gdev->big_endian = of_device_is_big_endian(dn);
err = devm_request_irq(&pdev->dev, timeout_irq,
brcmstb_gisb_timeout_handler, 0, pdev->name,
gdev);
if (err < 0)
return err;
err = devm_request_irq(&pdev->dev, tea_irq,
brcmstb_gisb_tea_handler, 0, pdev->name,
gdev);
if (err < 0)
return err;
/* If we do not have a valid mask, assume all masters are enabled */
if (of_property_read_u32(dn, "brcm,gisb-arb-master-mask",
&gdev->valid_mask))
gdev->valid_mask = 0xffffffff;
/* Proceed with reading the litteral names if we agree on the
* number of masters
*/
num_masters = of_property_count_strings(dn,
"brcm,gisb-arb-master-names");
if (hweight_long(gdev->valid_mask) == num_masters) {
first = ffs(gdev->valid_mask) - 1;
last = fls(gdev->valid_mask) - 1;
for (i = first; i < last; i++) {
if (!(gdev->valid_mask & BIT(i)))
continue;
of_property_read_string_index(dn,
"brcm,gisb-arb-master-names", j,
&gdev->master_names[i]);
j++;
}
}
err = sysfs_create_group(&pdev->dev.kobj, &gisb_arb_sysfs_attr_group);
if (err)
return err;
platform_set_drvdata(pdev, gdev);
list_add_tail(&gdev->next, &brcmstb_gisb_arb_device_list);
#ifdef CONFIG_ARM
hook_fault_code(22, brcmstb_bus_error_handler, SIGBUS, 0,
"imprecise external abort");
#endif
#ifdef CONFIG_MIPS
board_be_handler = brcmstb_bus_error_handler;
#endif
dev_info(&pdev->dev, "registered mem: %p, irqs: %d, %d\n",
gdev->base, timeout_irq, tea_irq);
return 0;
}
#ifdef CONFIG_PM_SLEEP
static int brcmstb_gisb_arb_suspend(struct device *dev)
{
struct platform_device *pdev = to_platform_device(dev);
struct brcmstb_gisb_arb_device *gdev = platform_get_drvdata(pdev);
gdev->saved_timeout = gisb_read(gdev, ARB_TIMER);
return 0;
}
/* Make sure we provide the same timeout value that was configured before, and
* do this before the GISB timeout interrupt handler has any chance to run.
*/
static int brcmstb_gisb_arb_resume_noirq(struct device *dev)
{
struct platform_device *pdev = to_platform_device(dev);
struct brcmstb_gisb_arb_device *gdev = platform_get_drvdata(pdev);
gisb_write(gdev, gdev->saved_timeout, ARB_TIMER);
return 0;
}
#else
#define brcmstb_gisb_arb_suspend NULL
#define brcmstb_gisb_arb_resume_noirq NULL
#endif
static const struct dev_pm_ops brcmstb_gisb_arb_pm_ops = {
.suspend = brcmstb_gisb_arb_suspend,
.resume_noirq = brcmstb_gisb_arb_resume_noirq,
};
static struct platform_driver brcmstb_gisb_arb_driver = {
.driver = {
.name = "brcm-gisb-arb",
.of_match_table = brcmstb_gisb_arb_of_match,
.pm = &brcmstb_gisb_arb_pm_ops,
},
};
static int __init brcm_gisb_driver_init(void)
{
return platform_driver_probe(&brcmstb_gisb_arb_driver,
brcmstb_gisb_arb_probe);
}
module_init(brcm_gisb_driver_init);
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