Commit Graph

5 Commits

Author SHA1 Message Date
John Baldwin
179fa75e6e Reassign copyright statements on several files from Advanced
Computing Technologies LLC to Hudson River Trading LLC.

Approved by:	Hudson River Trading LLC (who owns ACT LLC)
MFC after:	1 week
2015-04-23 14:22:20 +00:00
John Baldwin
1f22be4547 - Rename VM_MEMATTR_UNCACHED to VM_MEMATTR_WEAK_UNCACHEABLE on x86 to
be less ambiguous and more clearly identify what it means.  This
  attribute is what Intel refers to as UC-, and it's only difference
  relative to normal UC memory is that a WC MTRR will override a UC-
  PAT entry causing the memory to be treated as WC, whereas a UC PAT
  entry will always override the MTRR.
- Remove the VM_MEMATTR_UNCACHED alias from powerpc.
2012-03-29 16:51:22 +00:00
Alan Cox
3153e878dd Add support to the virtual memory system for configuring machine-
dependent memory attributes:

Rename vm_cache_mode_t to vm_memattr_t.  The new name reflects the
fact that there are machine-dependent memory attributes that have
nothing to do with controlling the cache's behavior.

Introduce vm_object_set_memattr() for setting the default memory
attributes that will be given to an object's pages.

Introduce and use pmap_page_{get,set}_memattr() for getting and
setting a page's machine-dependent memory attributes.  Add full
support for these functions on amd64 and i386 and stubs for them on
the other architectures.  The function pmap_page_set_memattr() is also
responsible for any other machine-dependent aspects of changing a
page's memory attributes, such as flushing the cache or updating the
direct map.  The uses include kmem_alloc_contig(), vm_page_alloc(),
and the device pager:

  kmem_alloc_contig() can now be used to allocate kernel memory with
  non-default memory attributes on amd64 and i386.

  vm_page_alloc() and the device pager will set the memory attributes
  for the real or fictitious page according to the object's default
  memory attributes.

Update the various pmap functions on amd64 and i386 that map pages to
incorporate each page's memory attributes in the mapping.

Notes: (1) Inherent to this design are safety features that prevent
the specification of inconsistent memory attributes by different
mappings on amd64 and i386.  In addition, the device pager provides a
warning when a device driver creates a fictitious page with memory
attributes that are inconsistent with the real page that the
fictitious page is an alias for. (2) Storing the machine-dependent
memory attributes for amd64 and i386 as a dedicated "int" in "struct
md_page" represents a compromise between space efficiency and the ease
of MFCing these changes to RELENG_7.

In collaboration with: jhb

Approved by:	re (kib)
2009-07-12 23:31:20 +00:00
Alan Cox
5797795f5a Correct the #endif comment.
Noticed by:	jmallett
Approved by:	re (kib)
2009-06-26 16:22:24 +00:00
Alan Cox
e999111ae7 This change is the next step in implementing the cache control functionality
required by video card drivers.  Specifically, this change introduces
vm_cache_mode_t with an appropriate VM_CACHE_DEFAULT definition on all
architectures.  In addition, this changes adds a vm_cache_mode_t parameter
to kmem_alloc_contig() and vm_phys_alloc_contig().  These will be the
interfaces for allocating mapped kernel memory and physical memory,
respectively, with non-default cache modes.

In collaboration with:	jhb
2009-06-26 04:47:43 +00:00