<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-dev/arch/powerpc/kernel/fpu.S, branch linus/master</title>
<subtitle>Linux kernel development work - see feature branches</subtitle>
<id>https://git.zx2c4.com/linux-dev/atom/arch/powerpc/kernel/fpu.S?h=linus%2Fmaster</id>
<link rel='self' href='https://git.zx2c4.com/linux-dev/atom/arch/powerpc/kernel/fpu.S?h=linus%2Fmaster'/>
<link rel='alternate' type='text/html' href='https://git.zx2c4.com/linux-dev/'/>
<updated>2021-12-16T10:31:45Z</updated>
<entry>
<title>powerpc/64s/interrupt: handle MSR EE and RI in interrupt entry wrapper</title>
<updated>2021-12-16T10:31:45Z</updated>
<author>
<name>Nicholas Piggin</name>
<email>npiggin@gmail.com</email>
</author>
<published>2021-09-22T14:54:48Z</published>
<link rel='alternate' type='text/html' href='https://git.zx2c4.com/linux-dev/commit/?id=ff0b0d6e1a7bc202241a9b1e28d1da4b744e0312'/>
<id>urn:sha1:ff0b0d6e1a7bc202241a9b1e28d1da4b744e0312</id>
<content type='text'>
The mtmsrd to enable MSR[RI] can be combined with the mtmsrd to enable
MSR[EE] in interrupt entry code, for those interrupts which enable EE.
This helps performance of important synchronous interrupts (e.g., page
faults).

This is similar to what commit dd152f70bdc1 ("powerpc/64s: system call
avoid setting MSR[RI] until we set MSR[EE]") does for system calls.

Do this by enabling EE and RI together at the beginning of the entry
wrapper if PACA_IRQ_HARD_DIS is clear, and only enabling RI if it is
set.

Asynchronous interrupts set PACA_IRQ_HARD_DIS, but synchronous ones
leave it unchanged, so by default they always get EE=1 unless they have
interrupted a caller that is hard disabled. When the sync interrupt
later calls interrupt_cond_local_irq_enable(), it will not require
another mtmsrd because MSR[EE] was already enabled here.

This avoids one mtmsrd L=1 for synchronous interrupts on 64s, which
saves about 20 cycles on POWER9. And for kernel-mode interrupts, both
synchronous and asynchronous, this saves an additional 40 cycles due to
the mtmsrd being moved ahead of mfspr SPRN_AMR, which prevents a SPR
scoreboard stall.

Signed-off-by: Nicholas Piggin &lt;npiggin@gmail.com&gt;
Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Link: https://lore.kernel.org/r/20210922145452.352571-3-npiggin@gmail.com

</content>
</entry>
<entry>
<title>powerpc/32: Remove unneccessary calculations in load_up_{fpu/altivec}</title>
<updated>2021-08-18T13:49:55Z</updated>
<author>
<name>Christophe Leroy</name>
<email>christophe.leroy@csgroup.eu</email>
</author>
<published>2021-08-18T08:47:28Z</published>
<link rel='alternate' type='text/html' href='https://git.zx2c4.com/linux-dev/commit/?id=51ed00e71f0130e0f3534b8e7d78facd16829426'/>
<id>urn:sha1:51ed00e71f0130e0f3534b8e7d78facd16829426</id>
<content type='text'>
No need to re-read SPRN_THREAD, we can calculate thread address
from current (r2).

And remove a reload of value 1 into r4 as r4 is already 1.

Signed-off-by: Christophe Leroy &lt;christophe.leroy@csgroup.eu&gt;
Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Link: https://lore.kernel.org/r/c04cce578b97a76a9e69a096698b1d89f721768a.1629276437.git.christophe.leroy@csgroup.eu

</content>
</entry>
<entry>
<title>powerpc/64s: avoid reloading (H)SRR registers if they are still valid</title>
<updated>2021-06-24T14:06:55Z</updated>
<author>
<name>Nicholas Piggin</name>
<email>npiggin@gmail.com</email>
</author>
<published>2021-06-17T15:51:03Z</published>
<link rel='alternate' type='text/html' href='https://git.zx2c4.com/linux-dev/commit/?id=59dc5bfca0cb6a29db1a50847684eb5c19f8f400'/>
<id>urn:sha1:59dc5bfca0cb6a29db1a50847684eb5c19f8f400</id>
<content type='text'>
When an interrupt is taken, the SRR registers are set to return to where
it left off. Unless they are modified in the meantime, or the return
address or MSR are modified, there is no need to reload these registers
when returning from interrupt.

Introduce per-CPU flags that track the validity of SRR and HSRR
registers. These are cleared when returning from interrupt, when
using the registers for something else (e.g., OPAL calls), when
adjusting the return address or MSR of a context, and when context
switching (which changes the return address and MSR).

This improves the performance of interrupt returns.

Signed-off-by: Nicholas Piggin &lt;npiggin@gmail.com&gt;
[mpe: Fold in fixup patch from Nick]
Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Link: https://lore.kernel.org/r/20210617155116.2167984-5-npiggin@gmail.com

</content>
</entry>
<entry>
<title>powerpc/32: Always enable data translation in exception prolog</title>
<updated>2021-03-29T02:22:05Z</updated>
<author>
<name>Christophe Leroy</name>
<email>christophe.leroy@csgroup.eu</email>
</author>
<published>2021-03-12T12:50:22Z</published>
<link rel='alternate' type='text/html' href='https://git.zx2c4.com/linux-dev/commit/?id=7aa8dd67f15731f659390018b5c9fd95f5975b3d'/>
<id>urn:sha1:7aa8dd67f15731f659390018b5c9fd95f5975b3d</id>
<content type='text'>
If the code can use a stack in vm area, it can also use a
stack in linear space.

Simplify code by removing old non VMAP stack code on PPC32.

That means the data translation is now re-enabled early in
exception prolog in all cases, not only when using VMAP stacks.

While we are touching EXCEPTION_PROLOG macros, remove the
unused for_rtas parameter in EXCEPTION_PROLOG_1.

Signed-off-by: Christophe Leroy &lt;christophe.leroy@csgroup.eu&gt;
Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Link: https://lore.kernel.org/r/7cd6440c60a7e8f4f035b245c57720f51e225aae.1615552866.git.christophe.leroy@csgroup.eu
</content>
</entry>
<entry>
<title>powerpc: Drop SYNC_601() ISYNC_601() and SYNC()</title>
<updated>2020-10-08T10:17:13Z</updated>
<author>
<name>Christophe Leroy</name>
<email>christophe.leroy@csgroup.eu</email>
</author>
<published>2020-09-29T06:48:34Z</published>
<link rel='alternate' type='text/html' href='https://git.zx2c4.com/linux-dev/commit/?id=d2a5cd83ee984c0e9fc172d2df9591c264261a52'/>
<id>urn:sha1:d2a5cd83ee984c0e9fc172d2df9591c264261a52</id>
<content type='text'>
Those macros are now empty at all time. Drop them.

Signed-off-by: Christophe Leroy &lt;christophe.leroy@csgroup.eu&gt;
Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Link: https://lore.kernel.org/r/7990bb63fc53e460bfa94f8040184881d9e6fbc3.1601362098.git.christophe.leroy@csgroup.eu
</content>
</entry>
<entry>
<title>powerpc/fpu: Drop cvt_fd() and cvt_df()</title>
<updated>2020-09-02T01:00:19Z</updated>
<author>
<name>Christophe Leroy</name>
<email>christophe.leroy@csgroup.eu</email>
</author>
<published>2020-08-06T12:20:34Z</published>
<link rel='alternate' type='text/html' href='https://git.zx2c4.com/linux-dev/commit/?id=63442de4301188129e1fcff144fbfb966ad5eb19'/>
<id>urn:sha1:63442de4301188129e1fcff144fbfb966ad5eb19</id>
<content type='text'>
Those two functions have been unused since commit identified below.
Drop them.

Fixes: 31bfdb036f12 ("powerpc: Use instruction emulation infrastructure to handle alignment faults")
Signed-off-by: Christophe Leroy &lt;christophe.leroy@csgroup.eu&gt;
Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Link: https://lore.kernel.org/r/d5641ada199b8dd2af16ad00a66084cf974f2704.1596716418.git.christophe.leroy@csgroup.eu
</content>
</entry>
<entry>
<title>powerpc: re-initialise lazy FPU/VEC counters on every fault</title>
<updated>2020-07-16T03:00:24Z</updated>
<author>
<name>Nicholas Piggin</name>
<email>npiggin@gmail.com</email>
</author>
<published>2020-06-23T23:41:39Z</published>
<link rel='alternate' type='text/html' href='https://git.zx2c4.com/linux-dev/commit/?id=b2b46304e9360f3dda49c9d8ba4a1478b9eecf1d'/>
<id>urn:sha1:b2b46304e9360f3dda49c9d8ba4a1478b9eecf1d</id>
<content type='text'>
When a FP/VEC/VSX unavailable fault loads registers and enables the
facility in the MSR, re-set the lazy restore counters to 1 rather
than incrementing them so every fault gets the same number of
restores before the next fault.

This probably shouldn't be a practical change because if a lazy counter
was non-zero then it should have been restored and would not cause a
fault when userspace tries to access it. However the code and comment
implies otherwise so that's misleading and unnecessary.

Signed-off-by: Nicholas Piggin &lt;npiggin@gmail.com&gt;
Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Link: https://lore.kernel.org/r/20200623234139.2262227-3-npiggin@gmail.com
</content>
</entry>
<entry>
<title>mm: reorder includes after introduction of linux/pgtable.h</title>
<updated>2020-06-09T16:39:13Z</updated>
<author>
<name>Mike Rapoport</name>
<email>rppt@linux.ibm.com</email>
</author>
<published>2020-06-09T04:32:42Z</published>
<link rel='alternate' type='text/html' href='https://git.zx2c4.com/linux-dev/commit/?id=65fddcfca8ad14778f71a57672fd01e8112d30fa'/>
<id>urn:sha1:65fddcfca8ad14778f71a57672fd01e8112d30fa</id>
<content type='text'>
The replacement of &lt;asm/pgrable.h&gt; with &lt;linux/pgtable.h&gt; made the include
of the latter in the middle of asm includes.  Fix this up with the aid of
the below script and manual adjustments here and there.

	import sys
	import re

	if len(sys.argv) is not 3:
	    print "USAGE: %s &lt;file&gt; &lt;header&gt;" % (sys.argv[0])
	    sys.exit(1)

	hdr_to_move="#include &lt;linux/%s&gt;" % sys.argv[2]
	moved = False
	in_hdrs = False

	with open(sys.argv[1], "r") as f:
	    lines = f.readlines()
	    for _line in lines:
		line = _line.rstrip('
')
		if line == hdr_to_move:
		    continue
		if line.startswith("#include &lt;linux/"):
		    in_hdrs = True
		elif not moved and in_hdrs:
		    moved = True
		    print hdr_to_move
		print line

Signed-off-by: Mike Rapoport &lt;rppt@linux.ibm.com&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Cc: Arnd Bergmann &lt;arnd@arndb.de&gt;
Cc: Borislav Petkov &lt;bp@alien8.de&gt;
Cc: Brian Cain &lt;bcain@codeaurora.org&gt;
Cc: Catalin Marinas &lt;catalin.marinas@arm.com&gt;
Cc: Chris Zankel &lt;chris@zankel.net&gt;
Cc: "David S. Miller" &lt;davem@davemloft.net&gt;
Cc: Geert Uytterhoeven &lt;geert@linux-m68k.org&gt;
Cc: Greentime Hu &lt;green.hu@gmail.com&gt;
Cc: Greg Ungerer &lt;gerg@linux-m68k.org&gt;
Cc: Guan Xuetao &lt;gxt@pku.edu.cn&gt;
Cc: Guo Ren &lt;guoren@kernel.org&gt;
Cc: Heiko Carstens &lt;heiko.carstens@de.ibm.com&gt;
Cc: Helge Deller &lt;deller@gmx.de&gt;
Cc: Ingo Molnar &lt;mingo@redhat.com&gt;
Cc: Ley Foon Tan &lt;ley.foon.tan@intel.com&gt;
Cc: Mark Salter &lt;msalter@redhat.com&gt;
Cc: Matthew Wilcox &lt;willy@infradead.org&gt;
Cc: Matt Turner &lt;mattst88@gmail.com&gt;
Cc: Max Filippov &lt;jcmvbkbc@gmail.com&gt;
Cc: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Cc: Michal Simek &lt;monstr@monstr.eu&gt;
Cc: Nick Hu &lt;nickhu@andestech.com&gt;
Cc: Paul Walmsley &lt;paul.walmsley@sifive.com&gt;
Cc: Richard Weinberger &lt;richard@nod.at&gt;
Cc: Rich Felker &lt;dalias@libc.org&gt;
Cc: Russell King &lt;linux@armlinux.org.uk&gt;
Cc: Stafford Horne &lt;shorne@gmail.com&gt;
Cc: Thomas Bogendoerfer &lt;tsbogend@alpha.franken.de&gt;
Cc: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Cc: Tony Luck &lt;tony.luck@intel.com&gt;
Cc: Vincent Chen &lt;deanbo422@gmail.com&gt;
Cc: Vineet Gupta &lt;vgupta@synopsys.com&gt;
Cc: Will Deacon &lt;will@kernel.org&gt;
Cc: Yoshinori Sato &lt;ysato@users.sourceforge.jp&gt;
Link: http://lkml.kernel.org/r/20200514170327.31389-4-rppt@kernel.org
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</content>
</entry>
<entry>
<title>mm: introduce include/linux/pgtable.h</title>
<updated>2020-06-09T16:39:13Z</updated>
<author>
<name>Mike Rapoport</name>
<email>rppt@linux.ibm.com</email>
</author>
<published>2020-06-09T04:32:38Z</published>
<link rel='alternate' type='text/html' href='https://git.zx2c4.com/linux-dev/commit/?id=ca5999fde0a1761665a38e4c9a72dbcd7d190a81'/>
<id>urn:sha1:ca5999fde0a1761665a38e4c9a72dbcd7d190a81</id>
<content type='text'>
The include/linux/pgtable.h is going to be the home of generic page table
manipulation functions.

Start with moving asm-generic/pgtable.h to include/linux/pgtable.h and
make the latter include asm/pgtable.h.

Signed-off-by: Mike Rapoport &lt;rppt@linux.ibm.com&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Cc: Arnd Bergmann &lt;arnd@arndb.de&gt;
Cc: Borislav Petkov &lt;bp@alien8.de&gt;
Cc: Brian Cain &lt;bcain@codeaurora.org&gt;
Cc: Catalin Marinas &lt;catalin.marinas@arm.com&gt;
Cc: Chris Zankel &lt;chris@zankel.net&gt;
Cc: "David S. Miller" &lt;davem@davemloft.net&gt;
Cc: Geert Uytterhoeven &lt;geert@linux-m68k.org&gt;
Cc: Greentime Hu &lt;green.hu@gmail.com&gt;
Cc: Greg Ungerer &lt;gerg@linux-m68k.org&gt;
Cc: Guan Xuetao &lt;gxt@pku.edu.cn&gt;
Cc: Guo Ren &lt;guoren@kernel.org&gt;
Cc: Heiko Carstens &lt;heiko.carstens@de.ibm.com&gt;
Cc: Helge Deller &lt;deller@gmx.de&gt;
Cc: Ingo Molnar &lt;mingo@redhat.com&gt;
Cc: Ley Foon Tan &lt;ley.foon.tan@intel.com&gt;
Cc: Mark Salter &lt;msalter@redhat.com&gt;
Cc: Matthew Wilcox &lt;willy@infradead.org&gt;
Cc: Matt Turner &lt;mattst88@gmail.com&gt;
Cc: Max Filippov &lt;jcmvbkbc@gmail.com&gt;
Cc: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Cc: Michal Simek &lt;monstr@monstr.eu&gt;
Cc: Nick Hu &lt;nickhu@andestech.com&gt;
Cc: Paul Walmsley &lt;paul.walmsley@sifive.com&gt;
Cc: Richard Weinberger &lt;richard@nod.at&gt;
Cc: Rich Felker &lt;dalias@libc.org&gt;
Cc: Russell King &lt;linux@armlinux.org.uk&gt;
Cc: Stafford Horne &lt;shorne@gmail.com&gt;
Cc: Thomas Bogendoerfer &lt;tsbogend@alpha.franken.de&gt;
Cc: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Cc: Tony Luck &lt;tony.luck@intel.com&gt;
Cc: Vincent Chen &lt;deanbo422@gmail.com&gt;
Cc: Vineet Gupta &lt;vgupta@synopsys.com&gt;
Cc: Will Deacon &lt;will@kernel.org&gt;
Cc: Yoshinori Sato &lt;ysato@users.sourceforge.jp&gt;
Link: http://lkml.kernel.org/r/20200514170327.31389-3-rppt@kernel.org
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</content>
</entry>
<entry>
<title>powerpc/32: Blacklist functions running with MMU disabled for kprobe</title>
<updated>2020-06-02T10:59:11Z</updated>
<author>
<name>Christophe Leroy</name>
<email>christophe.leroy@c-s.fr</email>
</author>
<published>2020-03-31T16:03:44Z</published>
<link rel='alternate' type='text/html' href='https://git.zx2c4.com/linux-dev/commit/?id=5f32e8361cba8c58c4f272a389296f489ecc2823'/>
<id>urn:sha1:5f32e8361cba8c58c4f272a389296f489ecc2823</id>
<content type='text'>
kprobe does not handle events happening in real mode, all
functions running with MMU disabled have to be blacklisted.

Signed-off-by: Christophe Leroy &lt;christophe.leroy@c-s.fr&gt;
Acked-by: Naveen N. Rao &lt;naveen.n.rao@linux.vnet.ibm.com&gt;
Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Link: https://lore.kernel.org/r/3bf57066d05518644dee0840af69d36ab5086729.1585670437.git.christophe.leroy@c-s.fr
</content>
</entry>
</feed>
