public inbox for linux-acpi@vger.kernel.org
 help / color / mirror / Atom feed
From: "Rafael J. Wysocki" <rjw@sisk.pl>
To: Bjorn Helgaas <bjorn.helgaas@hp.com>
Cc: Len Brown <lenb@kernel.org>,
	Matthew Garrett <mjg59@srcf.ucam.org>,
	Bob Moore <robert.moore@intel.com>, Adam Belay <abelay@mit.edu>,
	linux-acpi@vger.kernel.org
Subject: Re: [PATCH] PNPACPI: truncate _CRS windows with _LEN > _MAX - _MIN + 1
Date: Thu, 25 Mar 2010 21:19:33 +0100	[thread overview]
Message-ID: <201003252119.33497.rjw@sisk.pl> (raw)
In-Reply-To: <20100325163249.11395.76426.stgit@bob.kio>

On Thursday 25 March 2010, Bjorn Helgaas wrote:
> 
> The ACPI spec (sec 6.4.3.5 in v4.0) requires that for Address Space Resource
> Descriptors, _LEN <= _MAX - _MIN + 1 in all cases, but there are BIOSes that
> violate this.  We experimentally determined that Windows truncates the
> resource so it doesn't extend past _MAX, so let's do the same thing in
> Linux.
> 
> http://bugzilla.kernel.org/show_bug.cgi?id=15480
> 
> Signed-off-by: Bjorn Helgaas <bjorn.helgaas@hp.com>

Acked-by: Rafael J. Wysocki <rjw@sisk.pl>

> ---
> 
>  drivers/pnp/pnpacpi/rsparser.c |   42 +++++++++++++++++++++++++++++-----------
>  1 files changed, 30 insertions(+), 12 deletions(-)
> 
> 
> diff --git a/drivers/pnp/pnpacpi/rsparser.c b/drivers/pnp/pnpacpi/rsparser.c
> index 54514aa..fe5bfa9 100644
> --- a/drivers/pnp/pnpacpi/rsparser.c
> +++ b/drivers/pnp/pnpacpi/rsparser.c
> @@ -273,12 +273,33 @@ static void pnpacpi_parse_allocated_busresource(struct pnp_dev *dev,
>  	pnp_add_bus_resource(dev, start, end);
>  }
>  
> +static u64 addr_space_length(struct pnp_dev *dev, u64 min, u64 max, u64 len)
> +{
> +	u64 max_len;
> +
> +	max_len = max - min + 1;
> +	if (len <= max_len)
> +		return len;
> +
> +	/*
> +	 * Per 6.4.3.5, _LEN cannot exceed _MAX - _MIN + 1, but some BIOSes
> +	 * don't do this correctly, e.g.,
> +	 * https://bugzilla.kernel.org/show_bug.cgi?id=15480
> +	 */
> +	dev_info(&dev->dev,
> +	         "resource length %#llx doesn't fit in %#llx-%#llx, trimming\n",
> +		 (unsigned long long) len, (unsigned long long) min,
> +		 (unsigned long long) max);
> +	return max_len;
> +}
> +
>  static void pnpacpi_parse_allocated_address_space(struct pnp_dev *dev,
>  						  struct acpi_resource *res)
>  {
>  	struct acpi_resource_address64 addr, *p = &addr;
>  	acpi_status status;
>  	int window;
> +	u64 len;
>  
>  	status = acpi_resource_to_address64(res, p);
>  	if (!ACPI_SUCCESS(status)) {
> @@ -287,20 +308,18 @@ static void pnpacpi_parse_allocated_address_space(struct pnp_dev *dev,
>  		return;
>  	}
>  
> +	len = addr_space_length(dev, p->minimum, p->maximum, p->address_length);
>  	window = (p->producer_consumer == ACPI_PRODUCER) ? 1 : 0;
>  
>  	if (p->resource_type == ACPI_MEMORY_RANGE)
> -		pnpacpi_parse_allocated_memresource(dev,
> -			p->minimum, p->address_length,
> +		pnpacpi_parse_allocated_memresource(dev, p->minimum, len,
>  			p->info.mem.write_protect, window);
>  	else if (p->resource_type == ACPI_IO_RANGE)
> -		pnpacpi_parse_allocated_ioresource(dev,
> -			p->minimum, p->address_length,
> +		pnpacpi_parse_allocated_ioresource(dev, p->minimum, len,
>  			p->granularity == 0xfff ? ACPI_DECODE_10 :
>  				ACPI_DECODE_16, window);
>  	else if (p->resource_type == ACPI_BUS_NUMBER_RANGE)
> -		pnpacpi_parse_allocated_busresource(dev, p->minimum,
> -						    p->address_length);
> +		pnpacpi_parse_allocated_busresource(dev, p->minimum, len);
>  }
>  
>  static void pnpacpi_parse_allocated_ext_address_space(struct pnp_dev *dev,
> @@ -308,21 +327,20 @@ static void pnpacpi_parse_allocated_ext_address_space(struct pnp_dev *dev,
>  {
>  	struct acpi_resource_extended_address64 *p = &res->data.ext_address64;
>  	int window;
> +	u64 len;
>  
> +	len = addr_space_length(dev, p->minimum, p->maximum, p->address_length);
>  	window = (p->producer_consumer == ACPI_PRODUCER) ? 1 : 0;
>  
>  	if (p->resource_type == ACPI_MEMORY_RANGE)
> -		pnpacpi_parse_allocated_memresource(dev,
> -			p->minimum, p->address_length,
> +		pnpacpi_parse_allocated_memresource(dev, p->minimum, len,
>  			p->info.mem.write_protect, window);
>  	else if (p->resource_type == ACPI_IO_RANGE)
> -		pnpacpi_parse_allocated_ioresource(dev,
> -			p->minimum, p->address_length,
> +		pnpacpi_parse_allocated_ioresource(dev, p->minimum, len,
>  			p->granularity == 0xfff ? ACPI_DECODE_10 :
>  				ACPI_DECODE_16, window);
>  	else if (p->resource_type == ACPI_BUS_NUMBER_RANGE)
> -		pnpacpi_parse_allocated_busresource(dev, p->minimum,
> -						    p->address_length);
> +		pnpacpi_parse_allocated_busresource(dev, p->minimum, len);
>  }
>  
>  static acpi_status pnpacpi_allocated_resource(struct acpi_resource *res,
> 
> 
> 


  reply	other threads:[~2010-03-25 20:16 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2010-03-25 16:32 [PATCH] PNPACPI: truncate _CRS windows with _LEN > _MAX - _MIN + 1 Bjorn Helgaas
2010-03-25 20:19 ` Rafael J. Wysocki [this message]
2010-04-04  4:39 ` Len Brown

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=201003252119.33497.rjw@sisk.pl \
    --to=rjw@sisk.pl \
    --cc=abelay@mit.edu \
    --cc=bjorn.helgaas@hp.com \
    --cc=lenb@kernel.org \
    --cc=linux-acpi@vger.kernel.org \
    --cc=mjg59@srcf.ucam.org \
    --cc=robert.moore@intel.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox