linux-kernel - Re: [PATCH 6 of 7] x86: use early_ioremap in __acpi_map

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Message-ID: <20080912094955.GB14201@elte.hu>
Date:	Fri, 12 Sep 2008 11:49:55 +0200
From:	Ingo Molnar <mingo@...e.hu>
To:	Jeremy Fitzhardinge <jeremy@...p.org>
Cc:	Yinghai Lu <yhlu.kernel@...il.com>, linux-kernel@...r.kernel.org,
	Thomas Gleixner <tglx@...utronix.de>,
	"H. Peter Anvin" <hpa@...or.com>
Subject: Re: [PATCH 6 of 7] x86: use early_ioremap in __acpi_map_table


* Jeremy Fitzhardinge <jeremy@...p.org> wrote:

> Yinghai Lu wrote:
> > void __iomem *__init_refok
> > acpi_os_map_memory(acpi_physical_address phys, acpi_size size)
> > {
> >         if (phys > ULONG_MAX) {
> >                 printk(KERN_ERR PREFIX "Cannot map memory that high\n");
> >                 return NULL;
> >         }
> >         if (acpi_gbl_permanent_mmap)
> >                 /*
> >                 * ioremap checks to ensure this is in reserved space
> >                 */
> >                 return ioremap((unsigned long)phys, size);
> >         else
> >                 return __acpi_map_table((unsigned long)phys, size);
> > }
> > EXPORT_SYMBOL_GPL(acpi_os_map_memory);
> >
> > void acpi_os_unmap_memory(void __iomem * virt, acpi_size size)
> > {
> >         if (acpi_gbl_permanent_mmap) {
> >                 iounmap(virt);
> >         }
> > }
> > EXPORT_SYMBOL_GPL(acpi_os_unmap_memory);
> >
> > just let acpi_os_unmap_memory to call __acpi_unmap_table...
> >   
> 
> That was my first attempt.  Unfortunately a lot of the acpi code seems 
> pretty sloppy about unmapping its tables, and basically relies on 
> __acpi_map_table's current behaviour of removing the previous mapping 
> when creating the new mapping.

could we just emit a WARN_ON_ONCE() warning when we have to remove a 
previous mapping, so that the ACPI code can be fixed eventually?

	Ingo
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