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Re: [PATCH v2 04/25] mm: enhance region_is_ram() to distinguish 'unknown' vs 'mixed'

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On Fri, 2015-07-24 at 22:38 -0400, Dan Williams wrote:
> region_is_ram() is used to prevent the establishment of aliased mappings
> to physical "System RAM" with incompatible cache settings.  However, it
> uses "-1" to indicate both "unknown" memory ranges (ranges not described
> by platform firmware) and "mixed" ranges (where the parameters describe
> a range that partially overlaps "System RAM").
> 
> Fix this up by explicitly tracking the "unknown" vs "mixed" resource
> cases. In addition to clarifying that "-1" means the requested spanned
> RAM and non-RAM resource, this re-write also adds support for detecting
> when the requested range completely covers all of a resource.

Agreed - this is a good enhancement.

> Finally, the implementation treats overlaps between "unknown" and RAM as
> RAM.

This sounds right for this interface.  iomem_map_sanity_check() checks the
boundary condition with the resource table.

> Cc: Toshi Kani <toshi.kani@hp.com>
> Signed-off-by: Dan Williams <dan.j.williams@intel.com>

The changes look good as well.

Reviewed-by: Toshi Kani <toshi.kani@hp.com>

Thanks,
-Toshi
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[PATCH v2 00/25] replace ioremap_{cache|wt} with memremap Dan Williams <dan.j.williams@intel.com> - 2015-07-25 04:50 +0200
  [PATCH v2 04/25] mm: enhance region_is_ram() to distinguish  'unknown' vs 'mixed' Dan Williams <dan.j.williams@intel.com> - 2015-07-25 04:50 +0200
    Re: [PATCH v2 04/25] mm: enhance region_is_ram() to distinguish  'unknown' vs 'mixed' "Luis R. Rodriguez" <mcgrof@suse.com> - 2015-07-28 01:00 +0200
    Re: [PATCH v2 04/25] mm: enhance region_is_ram() to distinguish  'unknown' vs 'mixed' Toshi Kani <toshi.kani@hp.com> - 2015-07-28 23:40 +0200
  [PATCH v2 21/25] fbdev: switch from ioremap_wt to memremap Dan Williams <dan.j.williams@intel.com> - 2015-07-25 04:50 +0200
  [PATCH v2 10/25] x86: switch from ioremap_cache to memremap Dan Williams <dan.j.williams@intel.com> - 2015-07-25 04:50 +0200
  [PATCH v2 23/25] arch: remove ioremap_cache,  replace with arch_memremap Dan Williams <dan.j.williams@intel.com> - 2015-07-25 04:50 +0200
  [PATCH v2 01/25] mm, x86: Fix warning in ioremap RAM check Dan Williams <dan.j.williams@intel.com> - 2015-07-25 04:50 +0200
  [PATCH v2 17/25] intel-iommu: switch from ioremap_cache to memremap Dan Williams <dan.j.williams@intel.com> - 2015-07-25 04:50 +0200
    Re: [PATCH v2 17/25] intel-iommu: switch from ioremap_cache to  memremap Joerg Roedel <joro@8bytes.org> - 2015-08-03 16:30 +0200
  [PATCH v2 06/25] cleanup IORESOURCE_CACHEABLE vs ioremap() Dan Williams <dan.j.williams@intel.com> - 2015-07-25 04:50 +0200
  [PATCH v2 12/25] i915: switch from acpi_os_ioremap to ioremap Dan Williams <dan.j.williams@intel.com> - 2015-07-25 04:50 +0200
  [PATCH v2 20/25] sfi: switch from ioremap_cache to memremap Dan Williams <dan.j.williams@intel.com> - 2015-07-25 04:50 +0200
  [PATCH v2 13/25] acpi: switch from ioremap_cache to memremap Dan Williams <dan.j.williams@intel.com> - 2015-07-25 04:50 +0200
  [PATCH v2 22/25] pmem: switch from ioremap_wt to memremap Dan Williams <dan.j.williams@intel.com> - 2015-07-25 04:50 +0200
    Re: [PATCH v2 22/25] pmem: switch from ioremap_wt to memremap Ross Zwisler <ross.zwisler@linux.intel.com> - 2015-07-29 21:20 +0200
  [PATCH v2 19/25] pxa2xx-flash: switch from ioremap_cache to memremap Dan Williams <dan.j.williams@intel.com> - 2015-07-25 04:50 +0200
  [PATCH v2 24/25] arch: remove ioremap_wt, replace with arch_memremap Dan Williams <dan.j.williams@intel.com> - 2015-07-25 04:50 +0200
  [PATCH v2 02/25] mm, x86: Remove region_is_ram() call from ioremap Dan Williams <dan.j.williams@intel.com> - 2015-07-25 04:50 +0200
  [PATCH v2 14/25] toshiba laptop: replace ioremap_cache with ioremap Dan Williams <dan.j.williams@intel.com> - 2015-07-25 04:50 +0200
  [PATCH v2 25/25] pmem: convert to generic memremap Dan Williams <dan.j.williams@intel.com> - 2015-07-25 04:50 +0200
  [PATCH v2 05/25] arch, drivers: don't include <asm/io.h> directly,  use <linux/io.h> instead Dan Williams <dan.j.williams@intel.com> - 2015-07-25 05:00 +0200

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