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
Raw File
tc6387xb.c
/*
 * Toshiba TC6387XB support
 * Copyright (c) 2005 Ian Molton
 *
 * 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 file contains TC6387XB base support.
 *
 */

#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/clk.h>
#include <linux/err.h>
#include <linux/mfd/core.h>
#include <linux/mfd/tmio.h>
#include <linux/mfd/tc6387xb.h>
#include <linux/slab.h>

enum {
	TC6387XB_CELL_MMC,
};

struct tc6387xb {
	void __iomem *scr;
	struct clk *clk32k;
	struct resource rscr;
};

static struct resource tc6387xb_mmc_resources[] = {
	{
		.start = 0x800,
		.end   = 0x9ff,
		.flags = IORESOURCE_MEM,
	},
	{
		.start = 0,
		.end   = 0,
		.flags = IORESOURCE_IRQ,
	},
};

/*--------------------------------------------------------------------------*/

#ifdef CONFIG_PM
static int tc6387xb_suspend(struct platform_device *dev, pm_message_t state)
{
	struct tc6387xb *tc6387xb = platform_get_drvdata(dev);
	struct tc6387xb_platform_data *pdata = dev_get_platdata(&dev->dev);

	if (pdata && pdata->suspend)
		pdata->suspend(dev);
	clk_disable_unprepare(tc6387xb->clk32k);

	return 0;
}

static int tc6387xb_resume(struct platform_device *dev)
{
	struct tc6387xb *tc6387xb = platform_get_drvdata(dev);
	struct tc6387xb_platform_data *pdata = dev_get_platdata(&dev->dev);

	clk_prepare_enable(tc6387xb->clk32k);
	if (pdata && pdata->resume)
		pdata->resume(dev);

	tmio_core_mmc_resume(tc6387xb->scr + 0x200, 0,
		tc6387xb_mmc_resources[0].start & 0xfffe);

	return 0;
}
#else
#define tc6387xb_suspend  NULL
#define tc6387xb_resume   NULL
#endif

/*--------------------------------------------------------------------------*/

static void tc6387xb_mmc_pwr(struct platform_device *mmc, int state)
{
	struct platform_device *dev = to_platform_device(mmc->dev.parent);
	struct tc6387xb *tc6387xb = platform_get_drvdata(dev);

	tmio_core_mmc_pwr(tc6387xb->scr + 0x200, 0, state);
}

static void tc6387xb_mmc_clk_div(struct platform_device *mmc, int state)
{
	struct platform_device *dev = to_platform_device(mmc->dev.parent);
	struct tc6387xb *tc6387xb = platform_get_drvdata(dev);

	tmio_core_mmc_clk_div(tc6387xb->scr + 0x200, 0, state);
}


static int tc6387xb_mmc_enable(struct platform_device *mmc)
{
	struct platform_device *dev      = to_platform_device(mmc->dev.parent);
	struct tc6387xb *tc6387xb = platform_get_drvdata(dev);

	clk_prepare_enable(tc6387xb->clk32k);

	tmio_core_mmc_enable(tc6387xb->scr + 0x200, 0,
		tc6387xb_mmc_resources[0].start & 0xfffe);

	return 0;
}

static int tc6387xb_mmc_disable(struct platform_device *mmc)
{
	struct platform_device *dev      = to_platform_device(mmc->dev.parent);
	struct tc6387xb *tc6387xb = platform_get_drvdata(dev);

	clk_disable_unprepare(tc6387xb->clk32k);

	return 0;
}

static struct tmio_mmc_data tc6387xb_mmc_data = {
	.hclk = 24000000,
	.set_pwr = tc6387xb_mmc_pwr,
	.set_clk_div = tc6387xb_mmc_clk_div,
};

/*--------------------------------------------------------------------------*/

static const struct mfd_cell tc6387xb_cells[] = {
	[TC6387XB_CELL_MMC] = {
		.name = "tmio-mmc",
		.enable = tc6387xb_mmc_enable,
		.disable = tc6387xb_mmc_disable,
		.platform_data = &tc6387xb_mmc_data,
		.pdata_size    = sizeof(tc6387xb_mmc_data),
		.num_resources = ARRAY_SIZE(tc6387xb_mmc_resources),
		.resources = tc6387xb_mmc_resources,
	},
};

static int tc6387xb_probe(struct platform_device *dev)
{
	struct tc6387xb_platform_data *pdata = dev_get_platdata(&dev->dev);
	struct resource *iomem, *rscr;
	struct clk *clk32k;
	struct tc6387xb *tc6387xb;
	int irq, ret;

	iomem = platform_get_resource(dev, IORESOURCE_MEM, 0);
	if (!iomem)
		return -EINVAL;

	tc6387xb = kzalloc(sizeof(*tc6387xb), GFP_KERNEL);
	if (!tc6387xb)
		return -ENOMEM;

	ret  = platform_get_irq(dev, 0);
	if (ret >= 0)
		irq = ret;
	else
		goto err_no_irq;

	clk32k = clk_get(&dev->dev, "CLK_CK32K");
	if (IS_ERR(clk32k)) {
		ret = PTR_ERR(clk32k);
		goto err_no_clk;
	}

	rscr = &tc6387xb->rscr;
	rscr->name = "tc6387xb-core";
	rscr->start = iomem->start;
	rscr->end = iomem->start + 0xff;
	rscr->flags = IORESOURCE_MEM;

	ret = request_resource(iomem, rscr);
	if (ret)
		goto err_resource;

	tc6387xb->scr = ioremap(rscr->start, resource_size(rscr));
	if (!tc6387xb->scr) {
		ret = -ENOMEM;
		goto err_ioremap;
	}

	tc6387xb->clk32k = clk32k;
	platform_set_drvdata(dev, tc6387xb);

	if (pdata && pdata->enable)
		pdata->enable(dev);

	dev_info(&dev->dev, "Toshiba tc6387xb initialised\n");

	ret = mfd_add_devices(&dev->dev, dev->id, tc6387xb_cells,
			      ARRAY_SIZE(tc6387xb_cells), iomem, irq, NULL);

	if (!ret)
		return 0;

	iounmap(tc6387xb->scr);
err_ioremap:
	release_resource(&tc6387xb->rscr);
err_resource:
	clk_put(clk32k);
err_no_clk:
err_no_irq:
	kfree(tc6387xb);
	return ret;
}

static int tc6387xb_remove(struct platform_device *dev)
{
	struct tc6387xb *tc6387xb = platform_get_drvdata(dev);

	mfd_remove_devices(&dev->dev);
	iounmap(tc6387xb->scr);
	release_resource(&tc6387xb->rscr);
	clk_disable_unprepare(tc6387xb->clk32k);
	clk_put(tc6387xb->clk32k);
	kfree(tc6387xb);

	return 0;
}


static struct platform_driver tc6387xb_platform_driver = {
	.driver = {
		.name		= "tc6387xb",
	},
	.probe		= tc6387xb_probe,
	.remove		= tc6387xb_remove,
	.suspend        = tc6387xb_suspend,
	.resume         = tc6387xb_resume,
};

module_platform_driver(tc6387xb_platform_driver);

MODULE_DESCRIPTION("Toshiba TC6387XB core driver");
MODULE_LICENSE("GPL v2");
MODULE_AUTHOR("Ian Molton");
MODULE_ALIAS("platform:tc6387xb");

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