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Revision af8f3f514d193eb353f9b6cea503c55d074e6153 authored by Hanjun Guo on 04 January 2015, 10:55:02 UTC, committed by Rafael J. Wysocki on 05 January 2015, 22:32:42 UTC 
ACPI / processor: Convert apic_id to phys_id to make it arch agnostic
 
apic_id in MADT table is the CPU hardware id which identify
it self in the system for x86 and ia64, OSPM will use it for
SMP init to map APIC ID to logical cpu number in the early
boot, when the DSDT/SSDT (ACPI namespace) is scanned later, the
ACPI processor driver is probed and the driver will use acpi_id
in DSDT to get the apic_id, then map to the logical cpu number
which is needed by the processor driver.

Before ACPI 5.0, only x86 and ia64 were supported in ACPI spec,
so apic_id is used both in arch code and ACPI core which is
pretty fine. Since ACPI 5.0, ARM is supported by ACPI and
APIC is not available on ARM, this will confuse people when
apic_id is both used by x86 and ARM in one function.

So convert apic_id to phys_id (which is the original meaning)
in ACPI processor dirver to make it arch agnostic, but leave the
arch dependent code unchanged, no functional change.

Signed-off-by: Hanjun Guo <hanjun.guo@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
1 parent b7392d2
Raw File
stmp_device.c 
/*
 * Copyright (C) 1999 ARM Limited
 * Copyright (C) 2000 Deep Blue Solutions Ltd
 * Copyright 2006-2007,2010 Freescale Semiconductor, Inc. All Rights Reserved.
 * Copyright 2008 Juergen Beisert, kernel@pengutronix.de
 * Copyright 2009 Ilya Yanok, Emcraft Systems Ltd, yanok@emcraft.com
 * Copyright (C) 2011 Wolfram Sang, Pengutronix e.K.
 *
 * 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/errno.h>
#include <linux/delay.h>
#include <linux/module.h>
#include <linux/stmp_device.h>

#define STMP_MODULE_CLKGATE	(1 << 30)
#define STMP_MODULE_SFTRST	(1 << 31)

/*
 * Clear the bit and poll it cleared.  This is usually called with
 * a reset address and mask being either SFTRST(bit 31) or CLKGATE
 * (bit 30).
 */
static int stmp_clear_poll_bit(void __iomem *addr, u32 mask)
{
	int timeout = 0x400;

	writel(mask, addr + STMP_OFFSET_REG_CLR);
	udelay(1);
	while ((readl(addr) & mask) && --timeout)
		/* nothing */;

	return !timeout;
}

int stmp_reset_block(void __iomem *reset_addr)
{
	int ret;
	int timeout = 0x400;

	/* clear and poll SFTRST */
	ret = stmp_clear_poll_bit(reset_addr, STMP_MODULE_SFTRST);
	if (unlikely(ret))
		goto error;

	/* clear CLKGATE */
	writel(STMP_MODULE_CLKGATE, reset_addr + STMP_OFFSET_REG_CLR);

	/* set SFTRST to reset the block */
	writel(STMP_MODULE_SFTRST, reset_addr + STMP_OFFSET_REG_SET);
	udelay(1);

	/* poll CLKGATE becoming set */
	while ((!(readl(reset_addr) & STMP_MODULE_CLKGATE)) && --timeout)
		/* nothing */;
	if (unlikely(!timeout))
		goto error;

	/* clear and poll SFTRST */
	ret = stmp_clear_poll_bit(reset_addr, STMP_MODULE_SFTRST);
	if (unlikely(ret))
		goto error;

	/* clear and poll CLKGATE */
	ret = stmp_clear_poll_bit(reset_addr, STMP_MODULE_CLKGATE);
	if (unlikely(ret))
		goto error;

	return 0;

error:
	pr_err("%s(%p): module reset timeout\n", __func__, reset_addr);
	return -ETIMEDOUT;
}
EXPORT_SYMBOL(stmp_reset_block);
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