<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-toradex.git/arch/frv/include/asm/highmem.h, branch v3.1.7</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>mm: stack based kmap_atomic()</title>
<updated>2010-10-26T23:52:08+00:00</updated>
<author>
<name>Peter Zijlstra</name>
<email>a.p.zijlstra@chello.nl</email>
</author>
<published>2010-10-26T21:21:51+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=3e4d3af501cccdc8a8cca41bdbe57d54ad7e7e73'/>
<id>3e4d3af501cccdc8a8cca41bdbe57d54ad7e7e73</id>
<content type='text'>
Keep the current interface but ignore the KM_type and use a stack based
approach.

The advantage is that we get rid of crappy code like:

	#define __KM_PTE			\
		(in_nmi() ? KM_NMI_PTE : 	\
		 in_irq() ? KM_IRQ_PTE :	\
		 KM_PTE0)

and in general can stop worrying about what context we're in and what kmap
slots might be appropriate for that.

The downside is that FRV kmap_atomic() gets more expensive.

For now we use a CPP trick suggested by Andrew:

  #define kmap_atomic(page, args...) __kmap_atomic(page)

to avoid having to touch all kmap_atomic() users in a single patch.

[ not compiled on:
  - mn10300: the arch doesn't actually build with highmem to begin with ]

[akpm@linux-foundation.org: coding-style fixes]
[akpm@linux-foundation.org: fix up drivers/gpu/drm/i915/intel_overlay.c]
Acked-by: Rik van Riel &lt;riel@redhat.com&gt;
Signed-off-by: Peter Zijlstra &lt;a.p.zijlstra@chello.nl&gt;
Acked-by: Chris Metcalf &lt;cmetcalf@tilera.com&gt;
Cc: David Howells &lt;dhowells@redhat.com&gt;
Cc: Hugh Dickins &lt;hughd@google.com&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: Steven Rostedt &lt;rostedt@goodmis.org&gt;
Cc: Russell King &lt;rmk@arm.linux.org.uk&gt;
Cc: Ralf Baechle &lt;ralf@linux-mips.org&gt;
Cc: David Miller &lt;davem@davemloft.net&gt;
Cc: Paul Mackerras &lt;paulus@samba.org&gt;
Cc: Benjamin Herrenschmidt &lt;benh@kernel.crashing.org&gt;
Cc: Dave Airlie &lt;airlied@linux.ie&gt;
Cc: Li Zefan &lt;lizf@cn.fujitsu.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>
Keep the current interface but ignore the KM_type and use a stack based
approach.

The advantage is that we get rid of crappy code like:

	#define __KM_PTE			\
		(in_nmi() ? KM_NMI_PTE : 	\
		 in_irq() ? KM_IRQ_PTE :	\
		 KM_PTE0)

and in general can stop worrying about what context we're in and what kmap
slots might be appropriate for that.

The downside is that FRV kmap_atomic() gets more expensive.

For now we use a CPP trick suggested by Andrew:

  #define kmap_atomic(page, args...) __kmap_atomic(page)

to avoid having to touch all kmap_atomic() users in a single patch.

[ not compiled on:
  - mn10300: the arch doesn't actually build with highmem to begin with ]

[akpm@linux-foundation.org: coding-style fixes]
[akpm@linux-foundation.org: fix up drivers/gpu/drm/i915/intel_overlay.c]
Acked-by: Rik van Riel &lt;riel@redhat.com&gt;
Signed-off-by: Peter Zijlstra &lt;a.p.zijlstra@chello.nl&gt;
Acked-by: Chris Metcalf &lt;cmetcalf@tilera.com&gt;
Cc: David Howells &lt;dhowells@redhat.com&gt;
Cc: Hugh Dickins &lt;hughd@google.com&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: Steven Rostedt &lt;rostedt@goodmis.org&gt;
Cc: Russell King &lt;rmk@arm.linux.org.uk&gt;
Cc: Ralf Baechle &lt;ralf@linux-mips.org&gt;
Cc: David Miller &lt;davem@davemloft.net&gt;
Cc: Paul Mackerras &lt;paulus@samba.org&gt;
Cc: Benjamin Herrenschmidt &lt;benh@kernel.crashing.org&gt;
Cc: Dave Airlie &lt;airlied@linux.ie&gt;
Cc: Li Zefan &lt;lizf@cn.fujitsu.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>kmap_atomic: make kunmap_atomic() harder to misuse</title>
<updated>2010-08-10T03:44:54+00:00</updated>
<author>
<name>Cesar Eduardo Barros</name>
<email>cesarb@cesarb.net</email>
</author>
<published>2010-08-10T00:18:32+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=597781f3e51f48ef8e67be772196d9e9673752c4'/>
<id>597781f3e51f48ef8e67be772196d9e9673752c4</id>
<content type='text'>
kunmap_atomic() is currently at level -4 on Rusty's "Hard To Misuse"
list[1] ("Follow common convention and you'll get it wrong"), except in
some architectures when CONFIG_DEBUG_HIGHMEM is set[2][3].

kunmap() takes a pointer to a struct page; kunmap_atomic(), however, takes
takes a pointer to within the page itself.  This seems to once in a while
trip people up (the convention they are following is the one from
kunmap()).

Make it much harder to misuse, by moving it to level 9 on Rusty's list[4]
("The compiler/linker won't let you get it wrong").  This is done by
refusing to build if the type of its first argument is a pointer to a
struct page.

The real kunmap_atomic() is renamed to kunmap_atomic_notypecheck()
(which is what you would call in case for some strange reason calling it
with a pointer to a struct page is not incorrect in your code).

The previous version of this patch was compile tested on x86-64.

[1] http://ozlabs.org/~rusty/index.cgi/tech/2008-04-01.html
[2] In these cases, it is at level 5, "Do it right or it will always
    break at runtime."
[3] At least mips and powerpc look very similar, and sparc also seems to
    share a common ancestor with both; there seems to be quite some
    degree of copy-and-paste coding here. The include/asm/highmem.h file
    for these three archs mention x86 CPUs at its top.
[4] http://ozlabs.org/~rusty/index.cgi/tech/2008-03-30.html
[5] As an aside, could someone tell me why mn10300 uses unsigned long as
    the first parameter of kunmap_atomic() instead of void *?

Signed-off-by: Cesar Eduardo Barros &lt;cesarb@cesarb.net&gt;
Cc: Russell King &lt;linux@arm.linux.org.uk&gt; (arch/arm)
Cc: Ralf Baechle &lt;ralf@linux-mips.org&gt; (arch/mips)
Cc: David Howells &lt;dhowells@redhat.com&gt; (arch/frv, arch/mn10300)
Cc: Koichi Yasutake &lt;yasutake.koichi@jp.panasonic.com&gt; (arch/mn10300)
Cc: Kyle McMartin &lt;kyle@mcmartin.ca&gt; (arch/parisc)
Cc: Helge Deller &lt;deller@gmx.de&gt; (arch/parisc)
Cc: "James E.J. Bottomley" &lt;jejb@parisc-linux.org&gt; (arch/parisc)
Cc: Benjamin Herrenschmidt &lt;benh@kernel.crashing.org&gt; (arch/powerpc)
Cc: Paul Mackerras &lt;paulus@samba.org&gt; (arch/powerpc)
Cc: "David S. Miller" &lt;davem@davemloft.net&gt; (arch/sparc)
Cc: Thomas Gleixner &lt;tglx@linutronix.de&gt; (arch/x86)
Cc: Ingo Molnar &lt;mingo@redhat.com&gt; (arch/x86)
Cc: "H. Peter Anvin" &lt;hpa@zytor.com&gt; (arch/x86)
Cc: Arnd Bergmann &lt;arnd@arndb.de&gt; (include/asm-generic)
Cc: Rusty Russell &lt;rusty@rustcorp.com.au&gt; ("Hard To Misuse" list)
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>
kunmap_atomic() is currently at level -4 on Rusty's "Hard To Misuse"
list[1] ("Follow common convention and you'll get it wrong"), except in
some architectures when CONFIG_DEBUG_HIGHMEM is set[2][3].

kunmap() takes a pointer to a struct page; kunmap_atomic(), however, takes
takes a pointer to within the page itself.  This seems to once in a while
trip people up (the convention they are following is the one from
kunmap()).

Make it much harder to misuse, by moving it to level 9 on Rusty's list[4]
("The compiler/linker won't let you get it wrong").  This is done by
refusing to build if the type of its first argument is a pointer to a
struct page.

The real kunmap_atomic() is renamed to kunmap_atomic_notypecheck()
(which is what you would call in case for some strange reason calling it
with a pointer to a struct page is not incorrect in your code).

The previous version of this patch was compile tested on x86-64.

[1] http://ozlabs.org/~rusty/index.cgi/tech/2008-04-01.html
[2] In these cases, it is at level 5, "Do it right or it will always
    break at runtime."
[3] At least mips and powerpc look very similar, and sparc also seems to
    share a common ancestor with both; there seems to be quite some
    degree of copy-and-paste coding here. The include/asm/highmem.h file
    for these three archs mention x86 CPUs at its top.
[4] http://ozlabs.org/~rusty/index.cgi/tech/2008-03-30.html
[5] As an aside, could someone tell me why mn10300 uses unsigned long as
    the first parameter of kunmap_atomic() instead of void *?

Signed-off-by: Cesar Eduardo Barros &lt;cesarb@cesarb.net&gt;
Cc: Russell King &lt;linux@arm.linux.org.uk&gt; (arch/arm)
Cc: Ralf Baechle &lt;ralf@linux-mips.org&gt; (arch/mips)
Cc: David Howells &lt;dhowells@redhat.com&gt; (arch/frv, arch/mn10300)
Cc: Koichi Yasutake &lt;yasutake.koichi@jp.panasonic.com&gt; (arch/mn10300)
Cc: Kyle McMartin &lt;kyle@mcmartin.ca&gt; (arch/parisc)
Cc: Helge Deller &lt;deller@gmx.de&gt; (arch/parisc)
Cc: "James E.J. Bottomley" &lt;jejb@parisc-linux.org&gt; (arch/parisc)
Cc: Benjamin Herrenschmidt &lt;benh@kernel.crashing.org&gt; (arch/powerpc)
Cc: Paul Mackerras &lt;paulus@samba.org&gt; (arch/powerpc)
Cc: "David S. Miller" &lt;davem@davemloft.net&gt; (arch/sparc)
Cc: Thomas Gleixner &lt;tglx@linutronix.de&gt; (arch/x86)
Cc: Ingo Molnar &lt;mingo@redhat.com&gt; (arch/x86)
Cc: "H. Peter Anvin" &lt;hpa@zytor.com&gt; (arch/x86)
Cc: Arnd Bergmann &lt;arnd@arndb.de&gt; (include/asm-generic)
Cc: Rusty Russell &lt;rusty@rustcorp.com.au&gt; ("Hard To Misuse" list)
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>FRV: Move to arch/frv/include/asm/</title>
<updated>2009-04-10T00:48:06+00:00</updated>
<author>
<name>David Howells</name>
<email>dhowells@redhat.com</email>
</author>
<published>2009-04-10T00:48:06+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=e69cc9278831139660cb99bde52908f145338d77'/>
<id>e69cc9278831139660cb99bde52908f145338d77</id>
<content type='text'>
Move arch headers from include/asm-frv/ to arch/frv/include/asm/.

Signed-off-by: David Howells &lt;dhowells@redhat.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Move arch headers from include/asm-frv/ to arch/frv/include/asm/.

Signed-off-by: David Howells &lt;dhowells@redhat.com&gt;
</pre>
</div>
</content>
</entry>
</feed>
