Revision dc280d93623927570da279e99393879dbbab39e7 authored by Thomas Gleixner on 21 December 2016, 19:19:49 UTC, committed by Thomas Gleixner on 25 December 2016, 09:47:42 UTC
Developers manage to overwrite states blindly without thought. That's fatal and hard to debug. Add sanity checks to make it fail. This requries to restructure the code so that the dynamic state allocation happens in the same lock protected section as the actual store. Otherwise the previous assignment of 'Reserved' to the name field would trigger the overwrite check. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Sebastian Siewior <bigeasy@linutronix.de> Link: http://lkml.kernel.org/r/20161221192111.675234535@linutronix.de Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
1 parent 59fefd0
mcp-sa11x0.c
/*
* linux/drivers/mfd/mcp-sa11x0.c
*
* Copyright (C) 2001-2005 Russell King
*
* 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.
*
* SA11x0 MCP (Multimedia Communications Port) driver.
*
* MCP read/write timeouts from Jordi Colomer, rehacked by rmk.
*/
#include <linux/module.h>
#include <linux/io.h>
#include <linux/errno.h>
#include <linux/kernel.h>
#include <linux/delay.h>
#include <linux/spinlock.h>
#include <linux/platform_device.h>
#include <linux/pm.h>
#include <linux/mfd/mcp.h>
#include <mach/hardware.h>
#include <asm/mach-types.h>
#include <linux/platform_data/mfd-mcp-sa11x0.h>
#define DRIVER_NAME "sa11x0-mcp"
struct mcp_sa11x0 {
void __iomem *base0;
void __iomem *base1;
u32 mccr0;
u32 mccr1;
};
/* Register offsets */
#define MCCR0(m) ((m)->base0 + 0x00)
#define MCDR0(m) ((m)->base0 + 0x08)
#define MCDR1(m) ((m)->base0 + 0x0c)
#define MCDR2(m) ((m)->base0 + 0x10)
#define MCSR(m) ((m)->base0 + 0x18)
#define MCCR1(m) ((m)->base1 + 0x00)
#define priv(mcp) ((struct mcp_sa11x0 *)mcp_priv(mcp))
static void
mcp_sa11x0_set_telecom_divisor(struct mcp *mcp, unsigned int divisor)
{
struct mcp_sa11x0 *m = priv(mcp);
divisor /= 32;
m->mccr0 &= ~0x00007f00;
m->mccr0 |= divisor << 8;
writel_relaxed(m->mccr0, MCCR0(m));
}
static void
mcp_sa11x0_set_audio_divisor(struct mcp *mcp, unsigned int divisor)
{
struct mcp_sa11x0 *m = priv(mcp);
divisor /= 32;
m->mccr0 &= ~0x0000007f;
m->mccr0 |= divisor;
writel_relaxed(m->mccr0, MCCR0(m));
}
/*
* Write data to the device. The bit should be set after 3 subframe
* times (each frame is 64 clocks). We wait a maximum of 6 subframes.
* We really should try doing something more productive while we
* wait.
*/
static void
mcp_sa11x0_write(struct mcp *mcp, unsigned int reg, unsigned int val)
{
struct mcp_sa11x0 *m = priv(mcp);
int ret = -ETIME;
int i;
writel_relaxed(reg << 17 | MCDR2_Wr | (val & 0xffff), MCDR2(m));
for (i = 0; i < 2; i++) {
udelay(mcp->rw_timeout);
if (readl_relaxed(MCSR(m)) & MCSR_CWC) {
ret = 0;
break;
}
}
if (ret < 0)
printk(KERN_WARNING "mcp: write timed out\n");
}
/*
* Read data from the device. The bit should be set after 3 subframe
* times (each frame is 64 clocks). We wait a maximum of 6 subframes.
* We really should try doing something more productive while we
* wait.
*/
static unsigned int
mcp_sa11x0_read(struct mcp *mcp, unsigned int reg)
{
struct mcp_sa11x0 *m = priv(mcp);
int ret = -ETIME;
int i;
writel_relaxed(reg << 17 | MCDR2_Rd, MCDR2(m));
for (i = 0; i < 2; i++) {
udelay(mcp->rw_timeout);
if (readl_relaxed(MCSR(m)) & MCSR_CRC) {
ret = readl_relaxed(MCDR2(m)) & 0xffff;
break;
}
}
if (ret < 0)
printk(KERN_WARNING "mcp: read timed out\n");
return ret;
}
static void mcp_sa11x0_enable(struct mcp *mcp)
{
struct mcp_sa11x0 *m = priv(mcp);
writel(-1, MCSR(m));
m->mccr0 |= MCCR0_MCE;
writel_relaxed(m->mccr0, MCCR0(m));
}
static void mcp_sa11x0_disable(struct mcp *mcp)
{
struct mcp_sa11x0 *m = priv(mcp);
m->mccr0 &= ~MCCR0_MCE;
writel_relaxed(m->mccr0, MCCR0(m));
}
/*
* Our methods.
*/
static struct mcp_ops mcp_sa11x0 = {
.set_telecom_divisor = mcp_sa11x0_set_telecom_divisor,
.set_audio_divisor = mcp_sa11x0_set_audio_divisor,
.reg_write = mcp_sa11x0_write,
.reg_read = mcp_sa11x0_read,
.enable = mcp_sa11x0_enable,
.disable = mcp_sa11x0_disable,
};
static int mcp_sa11x0_probe(struct platform_device *dev)
{
struct mcp_plat_data *data = dev_get_platdata(&dev->dev);
struct resource *mem0, *mem1;
struct mcp_sa11x0 *m;
struct mcp *mcp;
int ret;
if (!data)
return -ENODEV;
mem0 = platform_get_resource(dev, IORESOURCE_MEM, 0);
mem1 = platform_get_resource(dev, IORESOURCE_MEM, 1);
if (!mem0 || !mem1)
return -ENXIO;
if (!request_mem_region(mem0->start, resource_size(mem0),
DRIVER_NAME)) {
ret = -EBUSY;
goto err_mem0;
}
if (!request_mem_region(mem1->start, resource_size(mem1),
DRIVER_NAME)) {
ret = -EBUSY;
goto err_mem1;
}
mcp = mcp_host_alloc(&dev->dev, sizeof(struct mcp_sa11x0));
if (!mcp) {
ret = -ENOMEM;
goto err_alloc;
}
mcp->owner = THIS_MODULE;
mcp->ops = &mcp_sa11x0;
mcp->sclk_rate = data->sclk_rate;
m = priv(mcp);
m->mccr0 = data->mccr0 | 0x7f7f;
m->mccr1 = data->mccr1;
m->base0 = ioremap(mem0->start, resource_size(mem0));
m->base1 = ioremap(mem1->start, resource_size(mem1));
if (!m->base0 || !m->base1) {
ret = -ENOMEM;
goto err_ioremap;
}
platform_set_drvdata(dev, mcp);
/*
* Initialise device. Note that we initially
* set the sampling rate to minimum.
*/
writel_relaxed(-1, MCSR(m));
writel_relaxed(m->mccr1, MCCR1(m));
writel_relaxed(m->mccr0, MCCR0(m));
/*
* Calculate the read/write timeout (us) from the bit clock
* rate. This is the period for 3 64-bit frames. Always
* round this time up.
*/
mcp->rw_timeout = (64 * 3 * 1000000 + mcp->sclk_rate - 1) /
mcp->sclk_rate;
ret = mcp_host_add(mcp, data->codec_pdata);
if (ret == 0)
return 0;
err_ioremap:
iounmap(m->base1);
iounmap(m->base0);
mcp_host_free(mcp);
err_alloc:
release_mem_region(mem1->start, resource_size(mem1));
err_mem1:
release_mem_region(mem0->start, resource_size(mem0));
err_mem0:
return ret;
}
static int mcp_sa11x0_remove(struct platform_device *dev)
{
struct mcp *mcp = platform_get_drvdata(dev);
struct mcp_sa11x0 *m = priv(mcp);
struct resource *mem0, *mem1;
if (m->mccr0 & MCCR0_MCE)
dev_warn(&dev->dev,
"device left active (missing disable call?)\n");
mem0 = platform_get_resource(dev, IORESOURCE_MEM, 0);
mem1 = platform_get_resource(dev, IORESOURCE_MEM, 1);
mcp_host_del(mcp);
iounmap(m->base1);
iounmap(m->base0);
mcp_host_free(mcp);
release_mem_region(mem1->start, resource_size(mem1));
release_mem_region(mem0->start, resource_size(mem0));
return 0;
}
#ifdef CONFIG_PM_SLEEP
static int mcp_sa11x0_suspend(struct device *dev)
{
struct mcp_sa11x0 *m = priv(dev_get_drvdata(dev));
if (m->mccr0 & MCCR0_MCE)
dev_warn(dev, "device left active (missing disable call?)\n");
writel(m->mccr0 & ~MCCR0_MCE, MCCR0(m));
return 0;
}
static int mcp_sa11x0_resume(struct device *dev)
{
struct mcp_sa11x0 *m = priv(dev_get_drvdata(dev));
writel_relaxed(m->mccr1, MCCR1(m));
writel_relaxed(m->mccr0, MCCR0(m));
return 0;
}
#endif
static const struct dev_pm_ops mcp_sa11x0_pm_ops = {
#ifdef CONFIG_PM_SLEEP
.suspend = mcp_sa11x0_suspend,
.freeze = mcp_sa11x0_suspend,
.poweroff = mcp_sa11x0_suspend,
.resume_noirq = mcp_sa11x0_resume,
.thaw_noirq = mcp_sa11x0_resume,
.restore_noirq = mcp_sa11x0_resume,
#endif
};
static struct platform_driver mcp_sa11x0_driver = {
.probe = mcp_sa11x0_probe,
.remove = mcp_sa11x0_remove,
.driver = {
.name = DRIVER_NAME,
.pm = &mcp_sa11x0_pm_ops,
},
};
/*
* This needs re-working
*/
module_platform_driver(mcp_sa11x0_driver);
MODULE_ALIAS("platform:" DRIVER_NAME);
MODULE_AUTHOR("Russell King <rmk@arm.linux.org.uk>");
MODULE_DESCRIPTION("SA11x0 multimedia communications port driver");
MODULE_LICENSE("GPL");
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