[PATCH v9 05/21] ARM64 / ACPI: Get RSDP and ACPI boot-time tables

[hanjun.guo@linaro.org (Hanjun Guo)]

On 2015?03?10? 19:19, Leif Lindholm wrote:
> On Tue, Mar 10, 2015 at 04:01:16PM +0800, Hanjun Guo wrote:
>>>> index 0000000..f052e7a
>>>> --- /dev/null
>>>> +++ b/arch/arm64/kernel/acpi.c
>>>> @@ -0,0 +1,101 @@
>>>> +/*
>>>> + *  ARM64 Specific Low-Level ACPI Boot Support
>>>> + *
>>>> + *  Copyright (C) 2013-2014, Linaro Ltd.
>>>> + *	Author: Al Stone <al.stone@linaro.org>
>>>> + *	Author: Graeme Gregory <graeme.gregory@linaro.org>
>>>> + *	Author: Hanjun Guo <hanjun.guo@linaro.org>
>>>> + *	Author: Tomasz Nowicki <tomasz.nowicki@linaro.org>
>>>> + *	Author: Naresh Bhat <naresh.bhat@linaro.org>
>>>> + *
>>>> + *  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.
>>>> + */
>>>> +
>>>> +#define pr_fmt(fmt) "ACPI: " fmt
>>>> +
>>>> +#include <linux/acpi.h>
>>>> +#include <linux/bootmem.h>
>>>> +#include <linux/cpumask.h>
>>>> +#include <linux/init.h>
>>>> +#include <linux/irq.h>
>>>> +#include <linux/irqdomain.h>
>>>> +#include <linux/memblock.h>
>>>> +#include <linux/smp.h>
>>>> +
>>>> +int acpi_noirq;			/* skip ACPI IRQ initialization */
>>>> +int acpi_disabled;
>>>> +EXPORT_SYMBOL(acpi_disabled);
>>>> +
>>>> +int acpi_pci_disabled;		/* skip ACPI PCI scan and IRQ initialization */
>>>> +EXPORT_SYMBOL(acpi_pci_disabled);
>>>> +
>>>> +/*
>>>> + * __acpi_map_table() will be called before page_init(), so early_ioremap()
>>>> + * or early_memremap() should be called here to for ACPI table mapping.
>>>> + */
>>>> +char *__init __acpi_map_table(unsigned long phys, unsigned long size)
>>>> +{
>>>> +	if (!phys || !size)
>>>
>>> Is there a reason to rule out physical address 0x0 ?
>>
>> No particular reasons, unless some arch/firmware limits, I'm
>> not sure if we need this check (x86 needs it), I'm CC Leif
>> to confirm.
>
> Nothing in UEFI explicitly bans using physical address 0 for anything,
> and nothing in the architecture reserves it. So I don't think this
> check is necessary.

Thanks for the confirmation, will remove the !phys check.

Hanjun