<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-toradex.git/drivers/xen, branch v4.3</title>
<subtitle>Linux kernel for Apalis and Colibri modules</subtitle>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/'/>
<entry>
<title>Merge branch 'akpm' (patches from Andrew)</title>
<updated>2015-09-11T01:19:42+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2015-09-11T01:19:42+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=33e247c7e58d335d70ecb84fd869091e2e4b8dcb'/>
<id>33e247c7e58d335d70ecb84fd869091e2e4b8dcb</id>
<content type='text'>
Merge third patch-bomb from Andrew Morton:

 - even more of the rest of MM

 - lib/ updates

 - checkpatch updates

 - small changes to a few scruffy filesystems

 - kmod fixes/cleanups

 - kexec updates

 - a dma-mapping cleanup series from hch

* emailed patches from Andrew Morton &lt;akpm@linux-foundation.org&gt;: (81 commits)
  dma-mapping: consolidate dma_set_mask
  dma-mapping: consolidate dma_supported
  dma-mapping: cosolidate dma_mapping_error
  dma-mapping: consolidate dma_{alloc,free}_noncoherent
  dma-mapping: consolidate dma_{alloc,free}_{attrs,coherent}
  mm: use vma_is_anonymous() in create_huge_pmd() and wp_huge_pmd()
  mm: make sure all file VMAs have -&gt;vm_ops set
  mm, mpx: add "vm_flags_t vm_flags" arg to do_mmap_pgoff()
  mm: mark most vm_operations_struct const
  namei: fix warning while make xmldocs caused by namei.c
  ipc: convert invalid scenarios to use WARN_ON
  zlib_deflate/deftree: remove bi_reverse()
  lib/decompress_unlzma: Do a NULL check for pointer
  lib/decompressors: use real out buf size for gunzip with kernel
  fs/affs: make root lookup from blkdev logical size
  sysctl: fix int -&gt; unsigned long assignments in INT_MIN case
  kexec: export KERNEL_IMAGE_SIZE to vmcoreinfo
  kexec: align crash_notes allocation to make it be inside one physical page
  kexec: remove unnecessary test in kimage_alloc_crash_control_pages()
  kexec: split kexec_load syscall from kexec core code
  ...
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Merge third patch-bomb from Andrew Morton:

 - even more of the rest of MM

 - lib/ updates

 - checkpatch updates

 - small changes to a few scruffy filesystems

 - kmod fixes/cleanups

 - kexec updates

 - a dma-mapping cleanup series from hch

* emailed patches from Andrew Morton &lt;akpm@linux-foundation.org&gt;: (81 commits)
  dma-mapping: consolidate dma_set_mask
  dma-mapping: consolidate dma_supported
  dma-mapping: cosolidate dma_mapping_error
  dma-mapping: consolidate dma_{alloc,free}_noncoherent
  dma-mapping: consolidate dma_{alloc,free}_{attrs,coherent}
  mm: use vma_is_anonymous() in create_huge_pmd() and wp_huge_pmd()
  mm: make sure all file VMAs have -&gt;vm_ops set
  mm, mpx: add "vm_flags_t vm_flags" arg to do_mmap_pgoff()
  mm: mark most vm_operations_struct const
  namei: fix warning while make xmldocs caused by namei.c
  ipc: convert invalid scenarios to use WARN_ON
  zlib_deflate/deftree: remove bi_reverse()
  lib/decompress_unlzma: Do a NULL check for pointer
  lib/decompressors: use real out buf size for gunzip with kernel
  fs/affs: make root lookup from blkdev logical size
  sysctl: fix int -&gt; unsigned long assignments in INT_MIN case
  kexec: export KERNEL_IMAGE_SIZE to vmcoreinfo
  kexec: align crash_notes allocation to make it be inside one physical page
  kexec: remove unnecessary test in kimage_alloc_crash_control_pages()
  kexec: split kexec_load syscall from kexec core code
  ...
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge tag 'for-linus-4.3-rc0b-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip</title>
<updated>2015-09-10T23:21:11+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2015-09-10T23:21:11+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=06ab838c2024db468855118087db16d8fa905ddc'/>
<id>06ab838c2024db468855118087db16d8fa905ddc</id>
<content type='text'>
Pull xen terminology fixes from David Vrabel:
 "Use the correct GFN/BFN terms more consistently"

* tag 'for-linus-4.3-rc0b-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip:
  xen/xenbus: Rename the variable xen_store_mfn to xen_store_gfn
  xen/privcmd: Further s/MFN/GFN/ clean-up
  hvc/xen: Further s/MFN/GFN clean-up
  video/xen-fbfront: Further s/MFN/GFN clean-up
  xen/tmem: Use xen_page_to_gfn rather than pfn_to_gfn
  xen: Use correctly the Xen memory terminologies
  arm/xen: implement correctly pfn_to_mfn
  xen: Make clear that swiotlb and biomerge are dealing with DMA address
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull xen terminology fixes from David Vrabel:
 "Use the correct GFN/BFN terms more consistently"

* tag 'for-linus-4.3-rc0b-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip:
  xen/xenbus: Rename the variable xen_store_mfn to xen_store_gfn
  xen/privcmd: Further s/MFN/GFN/ clean-up
  hvc/xen: Further s/MFN/GFN clean-up
  video/xen-fbfront: Further s/MFN/GFN clean-up
  xen/tmem: Use xen_page_to_gfn rather than pfn_to_gfn
  xen: Use correctly the Xen memory terminologies
  arm/xen: implement correctly pfn_to_mfn
  xen: Make clear that swiotlb and biomerge are dealing with DMA address
</pre>
</div>
</content>
</entry>
<entry>
<title>dma-mapping: consolidate dma_{alloc,free}_{attrs,coherent}</title>
<updated>2015-09-10T20:29:01+00:00</updated>
<author>
<name>Christoph Hellwig</name>
<email>hch@lst.de</email>
</author>
<published>2015-09-09T22:39:39+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=6894258eda2f9badc28c878086c0e54bd5b7fb30'/>
<id>6894258eda2f9badc28c878086c0e54bd5b7fb30</id>
<content type='text'>
Since 2009 we have a nice asm-generic header implementing lots of DMA API
functions for architectures using struct dma_map_ops, but unfortunately
it's still missing a lot of APIs that all architectures still have to
duplicate.

This series consolidates the remaining functions, although we still need
arch opt outs for two of them as a few architectures have very
non-standard implementations.

This patch (of 5):

The coherent DMA allocator works the same over all architectures supporting
dma_map operations.

This patch consolidates them and converges the minor differences:

 - the debug_dma helpers are now called from all architectures, including
   those that were previously missing them
 - dma_alloc_from_coherent and dma_release_from_coherent are now always
   called from the generic alloc/free routines instead of the ops
   dma-mapping-common.h always includes dma-coherent.h to get the defintions
   for them, or the stubs if the architecture doesn't support this feature
 - checks for -&gt;alloc / -&gt;free presence are removed.  There is only one
   magic instead of dma_map_ops without them (mic_dma_ops) and that one
   is x86 only anyway.

Besides that only x86 needs special treatment to replace a default devices
if none is passed and tweak the gfp_flags.  An optional arch hook is provided
for that.

[linux@roeck-us.net: fix build]
[jcmvbkbc@gmail.com: fix xtensa]
Signed-off-by: Christoph Hellwig &lt;hch@lst.de&gt;
Cc: Arnd Bergmann &lt;arnd@arndb.de&gt;
Cc: Russell King &lt;linux@arm.linux.org.uk&gt;
Cc: Catalin Marinas &lt;catalin.marinas@arm.com&gt;
Cc: Will Deacon &lt;will.deacon@arm.com&gt;
Cc: Yoshinori Sato &lt;ysato@users.sourceforge.jp&gt;
Cc: Michal Simek &lt;monstr@monstr.eu&gt;
Cc: Jonas Bonn &lt;jonas@southpole.se&gt;
Cc: Chris Metcalf &lt;cmetcalf@ezchip.com&gt;
Cc: Guan Xuetao &lt;gxt@mprc.pku.edu.cn&gt;
Cc: Ralf Baechle &lt;ralf@linux-mips.org&gt;
Cc: Benjamin Herrenschmidt &lt;benh@kernel.crashing.org&gt;
Cc: Ingo Molnar &lt;mingo@elte.hu&gt;
Cc: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Cc: "H. Peter Anvin" &lt;hpa@zytor.com&gt;
Cc: Andy Shevchenko &lt;andy.shevchenko@gmail.com&gt;
Signed-off-by: Guenter Roeck &lt;linux@roeck-us.net&gt;
Signed-off-by: Max Filippov &lt;jcmvbkbc@gmail.com&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Since 2009 we have a nice asm-generic header implementing lots of DMA API
functions for architectures using struct dma_map_ops, but unfortunately
it's still missing a lot of APIs that all architectures still have to
duplicate.

This series consolidates the remaining functions, although we still need
arch opt outs for two of them as a few architectures have very
non-standard implementations.

This patch (of 5):

The coherent DMA allocator works the same over all architectures supporting
dma_map operations.

This patch consolidates them and converges the minor differences:

 - the debug_dma helpers are now called from all architectures, including
   those that were previously missing them
 - dma_alloc_from_coherent and dma_release_from_coherent are now always
   called from the generic alloc/free routines instead of the ops
   dma-mapping-common.h always includes dma-coherent.h to get the defintions
   for them, or the stubs if the architecture doesn't support this feature
 - checks for -&gt;alloc / -&gt;free presence are removed.  There is only one
   magic instead of dma_map_ops without them (mic_dma_ops) and that one
   is x86 only anyway.

Besides that only x86 needs special treatment to replace a default devices
if none is passed and tweak the gfp_flags.  An optional arch hook is provided
for that.

[linux@roeck-us.net: fix build]
[jcmvbkbc@gmail.com: fix xtensa]
Signed-off-by: Christoph Hellwig &lt;hch@lst.de&gt;
Cc: Arnd Bergmann &lt;arnd@arndb.de&gt;
Cc: Russell King &lt;linux@arm.linux.org.uk&gt;
Cc: Catalin Marinas &lt;catalin.marinas@arm.com&gt;
Cc: Will Deacon &lt;will.deacon@arm.com&gt;
Cc: Yoshinori Sato &lt;ysato@users.sourceforge.jp&gt;
Cc: Michal Simek &lt;monstr@monstr.eu&gt;
Cc: Jonas Bonn &lt;jonas@southpole.se&gt;
Cc: Chris Metcalf &lt;cmetcalf@ezchip.com&gt;
Cc: Guan Xuetao &lt;gxt@mprc.pku.edu.cn&gt;
Cc: Ralf Baechle &lt;ralf@linux-mips.org&gt;
Cc: Benjamin Herrenschmidt &lt;benh@kernel.crashing.org&gt;
Cc: Ingo Molnar &lt;mingo@elte.hu&gt;
Cc: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Cc: "H. Peter Anvin" &lt;hpa@zytor.com&gt;
Cc: Andy Shevchenko &lt;andy.shevchenko@gmail.com&gt;
Signed-off-by: Guenter Roeck &lt;linux@roeck-us.net&gt;
Signed-off-by: Max Filippov &lt;jcmvbkbc@gmail.com&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>mm: mark most vm_operations_struct const</title>
<updated>2015-09-10T20:29:01+00:00</updated>
<author>
<name>Kirill A. Shutemov</name>
<email>kirill.shutemov@linux.intel.com</email>
</author>
<published>2015-09-09T22:39:26+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=7cbea8dc0127a95226c7722a738ac6534950ef67'/>
<id>7cbea8dc0127a95226c7722a738ac6534950ef67</id>
<content type='text'>
With two exceptions (drm/qxl and drm/radeon) all vm_operations_struct
structs should be constant.

Signed-off-by: Kirill A. Shutemov &lt;kirill.shutemov@linux.intel.com&gt;
Reviewed-by: Oleg Nesterov &lt;oleg@redhat.com&gt;
Cc: "H. Peter Anvin" &lt;hpa@zytor.com&gt;
Cc: Andy Lutomirski &lt;luto@amacapital.net&gt;
Cc: Dave Hansen &lt;dave.hansen@linux.intel.com&gt;
Cc: Ingo Molnar &lt;mingo@elte.hu&gt;
Cc: Minchan Kim &lt;minchan@kernel.org&gt;
Cc: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
With two exceptions (drm/qxl and drm/radeon) all vm_operations_struct
structs should be constant.

Signed-off-by: Kirill A. Shutemov &lt;kirill.shutemov@linux.intel.com&gt;
Reviewed-by: Oleg Nesterov &lt;oleg@redhat.com&gt;
Cc: "H. Peter Anvin" &lt;hpa@zytor.com&gt;
Cc: Andy Lutomirski &lt;luto@amacapital.net&gt;
Cc: Dave Hansen &lt;dave.hansen@linux.intel.com&gt;
Cc: Ingo Molnar &lt;mingo@elte.hu&gt;
Cc: Minchan Kim &lt;minchan@kernel.org&gt;
Cc: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge tag 'for-linus-4.3-rc0-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip</title>
<updated>2015-09-08T18:46:48+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2015-09-08T18:46:48+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=752240e74d650faa24425adc523f1308973ea51c'/>
<id>752240e74d650faa24425adc523f1308973ea51c</id>
<content type='text'>
Pull xen updates from David Vrabel:
 "Xen features and fixes for 4.3:

   - Convert xen-blkfront to the multiqueue API
   - [arm] Support binding event channels to different VCPUs.
   - [x86] Support &gt; 512 GiB in a PV guests (off by default as such a
     guest cannot be migrated with the current toolstack).
   - [x86] PMU support for PV dom0 (limited support for using perf with
     Xen and other guests)"

* tag 'for-linus-4.3-rc0-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip: (33 commits)
  xen: switch extra memory accounting to use pfns
  xen: limit memory to architectural maximum
  xen: avoid another early crash of memory limited dom0
  xen: avoid early crash of memory limited dom0
  arm/xen: Remove helpers which are PV specific
  xen/x86: Don't try to set PCE bit in CR4
  xen/PMU: PMU emulation code
  xen/PMU: Intercept PMU-related MSR and APIC accesses
  xen/PMU: Describe vendor-specific PMU registers
  xen/PMU: Initialization code for Xen PMU
  xen/PMU: Sysfs interface for setting Xen PMU mode
  xen: xensyms support
  xen: remove no longer needed p2m.h
  xen: allow more than 512 GB of RAM for 64 bit pv-domains
  xen: move p2m list if conflicting with e820 map
  xen: add explicit memblock_reserve() calls for special pages
  mm: provide early_memremap_ro to establish read-only mapping
  xen: check for initrd conflicting with e820 map
  xen: check pre-allocated page tables for conflict with memory map
  xen: check for kernel memory conflicting with memory layout
  ...
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull xen updates from David Vrabel:
 "Xen features and fixes for 4.3:

   - Convert xen-blkfront to the multiqueue API
   - [arm] Support binding event channels to different VCPUs.
   - [x86] Support &gt; 512 GiB in a PV guests (off by default as such a
     guest cannot be migrated with the current toolstack).
   - [x86] PMU support for PV dom0 (limited support for using perf with
     Xen and other guests)"

* tag 'for-linus-4.3-rc0-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip: (33 commits)
  xen: switch extra memory accounting to use pfns
  xen: limit memory to architectural maximum
  xen: avoid another early crash of memory limited dom0
  xen: avoid early crash of memory limited dom0
  arm/xen: Remove helpers which are PV specific
  xen/x86: Don't try to set PCE bit in CR4
  xen/PMU: PMU emulation code
  xen/PMU: Intercept PMU-related MSR and APIC accesses
  xen/PMU: Describe vendor-specific PMU registers
  xen/PMU: Initialization code for Xen PMU
  xen/PMU: Sysfs interface for setting Xen PMU mode
  xen: xensyms support
  xen: remove no longer needed p2m.h
  xen: allow more than 512 GB of RAM for 64 bit pv-domains
  xen: move p2m list if conflicting with e820 map
  xen: add explicit memblock_reserve() calls for special pages
  mm: provide early_memremap_ro to establish read-only mapping
  xen: check for initrd conflicting with e820 map
  xen: check pre-allocated page tables for conflict with memory map
  xen: check for kernel memory conflicting with memory layout
  ...
</pre>
</div>
</content>
</entry>
<entry>
<title>xen/xenbus: Rename the variable xen_store_mfn to xen_store_gfn</title>
<updated>2015-09-08T17:03:54+00:00</updated>
<author>
<name>Julien Grall</name>
<email>julien.grall@citrix.com</email>
</author>
<published>2015-08-07T16:34:42+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=5f51042f876b88a3b81a135cc4ca0adb3d246112'/>
<id>5f51042f876b88a3b81a135cc4ca0adb3d246112</id>
<content type='text'>
The variable xen_store_mfn is effectively storing a GFN and not an MFN.

Signed-off-by: Julien Grall &lt;julien.grall@citrix.com&gt;
Signed-off-by: David Vrabel &lt;david.vrabel@citrix.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
The variable xen_store_mfn is effectively storing a GFN and not an MFN.

Signed-off-by: Julien Grall &lt;julien.grall@citrix.com&gt;
Signed-off-by: David Vrabel &lt;david.vrabel@citrix.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>xen/privcmd: Further s/MFN/GFN/ clean-up</title>
<updated>2015-09-08T17:03:54+00:00</updated>
<author>
<name>Julien Grall</name>
<email>julien.grall@citrix.com</email>
</author>
<published>2015-08-07T16:34:41+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=a13d7201d7deedcbb6ac6efa94a1a7d34d3d79ec'/>
<id>a13d7201d7deedcbb6ac6efa94a1a7d34d3d79ec</id>
<content type='text'>
The privcmd code is mixing the usage of GFN and MFN within the same
functions which make the code difficult to understand when you only work
with auto-translated guests.

The privcmd driver is only dealing with GFN so replace all the mention
of MFN into GFN.

The ioctl structure used to map foreign change has been left unchanged
given that the userspace is using it. Nonetheless, add a comment to
explain the expected value within the "mfn" field.

Signed-off-by: Julien Grall &lt;julien.grall@citrix.com&gt;
Reviewed-by: David Vrabel &lt;david.vrabel@citrix.com&gt;
Signed-off-by: David Vrabel &lt;david.vrabel@citrix.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
The privcmd code is mixing the usage of GFN and MFN within the same
functions which make the code difficult to understand when you only work
with auto-translated guests.

The privcmd driver is only dealing with GFN so replace all the mention
of MFN into GFN.

The ioctl structure used to map foreign change has been left unchanged
given that the userspace is using it. Nonetheless, add a comment to
explain the expected value within the "mfn" field.

Signed-off-by: Julien Grall &lt;julien.grall@citrix.com&gt;
Reviewed-by: David Vrabel &lt;david.vrabel@citrix.com&gt;
Signed-off-by: David Vrabel &lt;david.vrabel@citrix.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>xen/tmem: Use xen_page_to_gfn rather than pfn_to_gfn</title>
<updated>2015-09-08T17:03:52+00:00</updated>
<author>
<name>Julien Grall</name>
<email>julien.grall@citrix.com</email>
</author>
<published>2015-08-07T16:34:38+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=a76e3cc32d872acd5104278d21d2084da07c16a8'/>
<id>a76e3cc32d872acd5104278d21d2084da07c16a8</id>
<content type='text'>
All the caller of xen_tmem_{get,put}_page have a struct page * in hand
and call pfn_to_gfn for the only benefits of these 2 functions.

Rather than passing the pfn in parameter, pass directly the page and use
directly xen_page_to_gfn.

Signed-off-by: Julien Grall &lt;julien.grall@citrix.com&gt;
Reviewed-by: Stefano Stabellini &lt;stefano.stabellini@eu.citrix.com&gt;
Signed-off-by: David Vrabel &lt;david.vrabel@citrix.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
All the caller of xen_tmem_{get,put}_page have a struct page * in hand
and call pfn_to_gfn for the only benefits of these 2 functions.

Rather than passing the pfn in parameter, pass directly the page and use
directly xen_page_to_gfn.

Signed-off-by: Julien Grall &lt;julien.grall@citrix.com&gt;
Reviewed-by: Stefano Stabellini &lt;stefano.stabellini@eu.citrix.com&gt;
Signed-off-by: David Vrabel &lt;david.vrabel@citrix.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>xen: Use correctly the Xen memory terminologies</title>
<updated>2015-09-08T17:03:49+00:00</updated>
<author>
<name>Julien Grall</name>
<email>julien.grall@citrix.com</email>
</author>
<published>2015-08-07T16:34:37+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=0df4f266b3af90442bbeb5e685a84a80745beba0'/>
<id>0df4f266b3af90442bbeb5e685a84a80745beba0</id>
<content type='text'>
Based on include/xen/mm.h [1], Linux is mistakenly using MFN when GFN
is meant, I suspect this is because the first support for Xen was for
PV. This resulted in some misimplementation of helpers on ARM and
confused developers about the expected behavior.

For instance, with pfn_to_mfn, we expect to get an MFN based on the name.
Although, if we look at the implementation on x86, it's returning a GFN.

For clarity and avoid new confusion, replace any reference to mfn with
gfn in any helpers used by PV drivers. The x86 code will still keep some
reference of pfn_to_mfn which may be used by all kind of guests
No changes as been made in the hypercall field, even
though they may be invalid, in order to keep the same as the defintion
in xen repo.

Note that page_to_mfn has been renamed to xen_page_to_gfn to avoid a
name to close to the KVM function gfn_to_page.

Take also the opportunity to simplify simple construction such
as pfn_to_mfn(page_to_pfn(page)) into xen_page_to_gfn. More complex clean up
will come in follow-up patches.

[1] http://xenbits.xen.org/gitweb/?p=xen.git;a=commitdiff;h=e758ed14f390342513405dd766e874934573e6cb

Signed-off-by: Julien Grall &lt;julien.grall@citrix.com&gt;
Reviewed-by: Stefano Stabellini &lt;stefano.stabellini@eu.citrix.com&gt;
Acked-by: Dmitry Torokhov &lt;dmitry.torokhov@gmail.com&gt;
Acked-by: Wei Liu &lt;wei.liu2@citrix.com&gt;
Signed-off-by: David Vrabel &lt;david.vrabel@citrix.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Based on include/xen/mm.h [1], Linux is mistakenly using MFN when GFN
is meant, I suspect this is because the first support for Xen was for
PV. This resulted in some misimplementation of helpers on ARM and
confused developers about the expected behavior.

For instance, with pfn_to_mfn, we expect to get an MFN based on the name.
Although, if we look at the implementation on x86, it's returning a GFN.

For clarity and avoid new confusion, replace any reference to mfn with
gfn in any helpers used by PV drivers. The x86 code will still keep some
reference of pfn_to_mfn which may be used by all kind of guests
No changes as been made in the hypercall field, even
though they may be invalid, in order to keep the same as the defintion
in xen repo.

Note that page_to_mfn has been renamed to xen_page_to_gfn to avoid a
name to close to the KVM function gfn_to_page.

Take also the opportunity to simplify simple construction such
as pfn_to_mfn(page_to_pfn(page)) into xen_page_to_gfn. More complex clean up
will come in follow-up patches.

[1] http://xenbits.xen.org/gitweb/?p=xen.git;a=commitdiff;h=e758ed14f390342513405dd766e874934573e6cb

Signed-off-by: Julien Grall &lt;julien.grall@citrix.com&gt;
Reviewed-by: Stefano Stabellini &lt;stefano.stabellini@eu.citrix.com&gt;
Acked-by: Dmitry Torokhov &lt;dmitry.torokhov@gmail.com&gt;
Acked-by: Wei Liu &lt;wei.liu2@citrix.com&gt;
Signed-off-by: David Vrabel &lt;david.vrabel@citrix.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>xen: Make clear that swiotlb and biomerge are dealing with DMA address</title>
<updated>2015-09-08T16:10:52+00:00</updated>
<author>
<name>Julien Grall</name>
<email>julien.grall@citrix.com</email>
</author>
<published>2015-08-07T16:34:35+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=32e09870eedfb501a6cb5729d8c23f44f8a7cbdd'/>
<id>32e09870eedfb501a6cb5729d8c23f44f8a7cbdd</id>
<content type='text'>
The swiotlb is required when programming a DMA address on ARM when a
device is not protected by an IOMMU.

In this case, the DMA address should always be equal to the machine address.
For DOM0 memory, Xen ensure it by have an identity mapping between the
guest address and host address. However, when mapping a foreign grant
reference, the 1:1 model doesn't work.

For ARM guest, most of the callers of pfn_to_mfn expects to get a GFN
(Guest Frame Number), i.e a PFN (Page Frame Number) from the Linux point
of view given that all ARM guest are auto-translated.

Even though the name pfn_to_mfn is misleading, we need to ensure that
those caller get a GFN and not by mistake a MFN. In pratical, I haven't
seen error related to this but we should fix it for the sake of
correctness.

In order to fix the implementation of pfn_to_mfn on ARM in a follow-up
patch, we have to introduce new helpers to return the DMA from a PFN and
the invert.

On x86, the new helpers will be an alias of pfn_to_mfn and mfn_to_pfn.

The helpers will be used in swiotlb and xen_biovec_phys_mergeable.

This is necessary in the latter because we have to ensure that the
biovec code will not try to merge a biovec using foreign page and
another using Linux memory.

Lastly, the helper mfn_to_local_pfn has been renamed to bfn_to_local_pfn
given that the only usage was in swiotlb.

Signed-off-by: Julien Grall &lt;julien.grall@citrix.com&gt;
Reviewed-by: Stefano Stabellini &lt;stefano.stabellini@eu.citrix.com&gt;
Signed-off-by: David Vrabel &lt;david.vrabel@citrix.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
The swiotlb is required when programming a DMA address on ARM when a
device is not protected by an IOMMU.

In this case, the DMA address should always be equal to the machine address.
For DOM0 memory, Xen ensure it by have an identity mapping between the
guest address and host address. However, when mapping a foreign grant
reference, the 1:1 model doesn't work.

For ARM guest, most of the callers of pfn_to_mfn expects to get a GFN
(Guest Frame Number), i.e a PFN (Page Frame Number) from the Linux point
of view given that all ARM guest are auto-translated.

Even though the name pfn_to_mfn is misleading, we need to ensure that
those caller get a GFN and not by mistake a MFN. In pratical, I haven't
seen error related to this but we should fix it for the sake of
correctness.

In order to fix the implementation of pfn_to_mfn on ARM in a follow-up
patch, we have to introduce new helpers to return the DMA from a PFN and
the invert.

On x86, the new helpers will be an alias of pfn_to_mfn and mfn_to_pfn.

The helpers will be used in swiotlb and xen_biovec_phys_mergeable.

This is necessary in the latter because we have to ensure that the
biovec code will not try to merge a biovec using foreign page and
another using Linux memory.

Lastly, the helper mfn_to_local_pfn has been renamed to bfn_to_local_pfn
given that the only usage was in swiotlb.

Signed-off-by: Julien Grall &lt;julien.grall@citrix.com&gt;
Reviewed-by: Stefano Stabellini &lt;stefano.stabellini@eu.citrix.com&gt;
Signed-off-by: David Vrabel &lt;david.vrabel@citrix.com&gt;
</pre>
</div>
</content>
</entry>
</feed>
