linux-stable.git/arch/powerpc/kernel/Makefile, branch v5.16.2

powerpc: clean vdso32 and vdso64 directories

2021-11-15T04:46:45+00:00

Since commit bce74491c300 ("powerpc/vdso: fix unnecessary rebuilds of
vgettimeofday.o"), "make ARCH=powerpc clean" does not clean up the
arch/powerpc/kernel/{vdso32,vdso64} directories.

Use the subdir- trick to let "make clean" descend into them.

Fixes: bce74491c300 ("powerpc/vdso: fix unnecessary rebuilds of vgettimeofday.o")
Signed-off-by: Masahiro Yamada 
Signed-off-by: Michael Ellerman 
Link: https://lore.kernel.org/r/20211109185015.615517-1-masahiroy@kernel.org

Revert "powerpc/audit: Convert powerpc to AUDIT_ARCH_COMPAT_GENERIC"

2021-10-27T11:30:32+00:00

This reverts commit 566af8cda399c088763d07464463dc871c943b54.

This caused some conflicts vs the audit tree, and the audit maintainers
would prefer we postpone this to the next merge window so we have more
time for testing.

Signed-off-by: Michael Ellerman

powerpc/32: Add support for out-of-line static calls

2021-10-22T04:22:05+00:00

Add support for out-of-line static calls on PPC32. This change
improve performance of calls to global function pointers by
using direct calls instead of indirect calls.

The trampoline is initialy populated with a 'blr' or branch to target,
followed by an unreachable long jump sequence.

In order to cater with parallele execution, the trampoline needs to
be updated in a way that ensures it remains consistent at all time.
This means we can't use the traditional lis/addi to load r12 with
the target address, otherwise there would be a window during which
the first instruction contains the upper part of the new target
address while the second instruction still contains the lower part of
the old target address. To avoid that the target address is stored
just after the 'bctr' and loaded from there with a single instruction.

Then, depending on the target distance, arch_static_call_transform()
will either replace the first instruction by a direct 'bl ' or
'nop' in order to have the trampoline fall through the long jump
sequence.

For the special case of __static_call_return0(), to avoid the risk of
a far branch, a version of it is inlined at the end of the trampoline.

Performancewise the long jump sequence is probably not better than
the indirect calls set by GCC when we don't use static calls, but
such calls are unlikely to be required on powerpc32: With most
configurations the kernel size is far below 32 Mbytes so only
modules may happen to be too far. And even modules are likely to
be close enough as they are allocated below the kernel core and
as close as possible of the kernel text.

static_call selftest is running successfully with this change.

With this patch, __do_irq() has the following sequence to trace
irq entries:

	c0004a00 <__SCT__tp_func_irq_entry>:
	c0004a00:	48 00 00 e0 	b       c0004ae0 <__traceiter_irq_entry>
	c0004a04:	3d 80 c0 00 	lis     r12,-16384
	c0004a08:	81 8c 4a 1c 	lwz     r12,18972(r12)
	c0004a0c:	7d 89 03 a6 	mtctr   r12
	c0004a10:	4e 80 04 20 	bctr
	c0004a14:	38 60 00 00 	li      r3,0
	c0004a18:	4e 80 00 20 	blr
	c0004a1c:	00 00 00 00 	.long 0x0
...
	c0005654 <__do_irq>:
...
	c0005664:	7c 7f 1b 78 	mr      r31,r3
...
	c00056a0:	81 22 00 00 	lwz     r9,0(r2)
	c00056a4:	39 29 00 01 	addi    r9,r9,1
	c00056a8:	91 22 00 00 	stw     r9,0(r2)
	c00056ac:	3d 20 c0 af 	lis     r9,-16209
	c00056b0:	81 29 74 cc 	lwz     r9,29900(r9)
	c00056b4:	2c 09 00 00 	cmpwi   r9,0
	c00056b8:	41 82 00 10 	beq     c00056c8 <__do_irq+0x74>
	c00056bc:	80 69 00 04 	lwz     r3,4(r9)
	c00056c0:	7f e4 fb 78 	mr      r4,r31
	c00056c4:	4b ff f3 3d 	bl      c0004a00 <__SCT__tp_func_irq_entry>

Before this patch, __do_irq() was doing the following to trace irq
entries:

	c0005700 <__do_irq>:
...
	c0005710:	7c 7e 1b 78 	mr      r30,r3
...
	c000574c:	93 e1 00 0c 	stw     r31,12(r1)
	c0005750:	81 22 00 00 	lwz     r9,0(r2)
	c0005754:	39 29 00 01 	addi    r9,r9,1
	c0005758:	91 22 00 00 	stw     r9,0(r2)
	c000575c:	3d 20 c0 af 	lis     r9,-16209
	c0005760:	83 e9 f4 cc 	lwz     r31,-2868(r9)
	c0005764:	2c 1f 00 00 	cmpwi   r31,0
	c0005768:	41 82 00 24 	beq     c000578c <__do_irq+0x8c>
	c000576c:	81 3f 00 00 	lwz     r9,0(r31)
	c0005770:	80 7f 00 04 	lwz     r3,4(r31)
	c0005774:	7d 29 03 a6 	mtctr   r9
	c0005778:	7f c4 f3 78 	mr      r4,r30
	c000577c:	4e 80 04 21 	bctrl
	c0005780:	85 3f 00 0c 	lwzu    r9,12(r31)
	c0005784:	2c 09 00 00 	cmpwi   r9,0
	c0005788:	40 82 ff e4 	bne     c000576c <__do_irq+0x6c>

Behind the fact of now using a direct 'bl' instead of a
'load/mtctr/bctr' sequence, we can also see that we get one less
register on the stack.

Signed-off-by: Christophe Leroy 
Acked-by: Peter Zijlstra (Intel) 
Signed-off-by: Michael Ellerman 
Link: https://lore.kernel.org/r/6ec2a7865ed6a5ec54ab46d026785bafe1d837ea.1630484892.git.christophe.leroy@csgroup.eu

powerpc/audit: Convert powerpc to AUDIT_ARCH_COMPAT_GENERIC

2021-10-22T04:22:04+00:00

Commit e65e1fc2d24b ("[PATCH] syscall class hookup for all normal
targets") added generic support for AUDIT but that didn't include
support for bi-arch like powerpc.

Commit 4b58841149dc ("audit: Add generic compat syscall support")
added generic support for bi-arch.

Convert powerpc to that bi-arch generic audit support.

Signed-off-by: Christophe Leroy 
Signed-off-by: Michael Ellerman 
Link: https://lore.kernel.org/r/a4b3951d1191d4183d92a07a6097566bde60d00a.1629812058.git.christophe.leroy@csgroup.eu

powerpc: rename powerpc_debugfs_root to arch_debugfs_dir

2021-08-13T12:04:26+00:00

No functional change in this patch. arch_debugfs_dir is the generic kernel
name declared in linux/debugfs.h for arch-specific debugfs directory.
Architectures like x86/s390 already use the name. Rename powerpc
specific powerpc_debugfs_root to arch_debugfs_dir.

Signed-off-by: Aneesh Kumar K.V 
Signed-off-by: Michael Ellerman 
Link: https://lore.kernel.org/r/20210812132831.233794-2-aneesh.kumar@linux.ibm.com

powerpc/vdso: Make sure vdso_wrapper.o is rebuilt everytime vdso.so is rebuilt

2021-04-01T13:18:09+00:00

Commit bce74491c300 ("powerpc/vdso: fix unnecessary rebuilds of
vgettimeofday.o") moved vdso32_wrapper.o and vdso64_wrapper.o out
of arch/powerpc/kernel/vdso[32/64]/ and removed the dependencies in
the Makefile. This leads to the wrappers not being re-build hence the
kernel embedding the old vdso library.

Add back missing dependencies to ensure vdso32_wrapper.o and vdso64_wrapper.o
are rebuilt when vdso32.so.dbg and vdso64.so.dbg are changed.

Fixes: bce74491c300 ("powerpc/vdso: fix unnecessary rebuilds of vgettimeofday.o")
Cc: stable@vger.kernel.org
Signed-off-by: Christophe Leroy 
Signed-off-by: Michael Ellerman 
Link: https://lore.kernel.org/r/8bb015bc98c51d8ced581415b7e3d157e18da7c9.1617181918.git.christophe.leroy@csgroup.eu

Merge tag 'powerpc-5.12-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux

2021-02-22T22:34:00+00:00

Pull powerpc updates from Michael Ellerman:

 - A large series adding wrappers for our interrupt handlers, so that
   irq/nmi/user tracking can be isolated in the wrappers rather than
   spread in each handler.

 - Conversion of the 32-bit syscall handling into C.

 - A series from Nick to streamline our TLB flushing when using the
   Radix MMU.

 - Switch to using queued spinlocks by default for 64-bit server CPUs.

 - A rework of our PCI probing so that it happens later in boot, when
   more generic infrastructure is available.

 - Two small fixes to allow 32-bit little-endian processes to run on
   64-bit kernels.

 - Other smaller features, fixes & cleanups.

Thanks to: Alexey Kardashevskiy, Ananth N Mavinakayanahalli, Aneesh
Kumar K.V, Athira Rajeev, Bhaskar Chowdhury, Cédric Le Goater, Chengyang
Fan, Christophe Leroy, Christopher M. Riedl, Fabiano Rosas, Florian
Fainelli, Frederic Barrat, Ganesh Goudar, Hari Bathini, Jiapeng Chong,
Joseph J Allen, Kajol Jain, Markus Elfring, Michal Suchanek, Nathan
Lynch, Naveen N. Rao, Nicholas Piggin, Oliver O'Halloran, Pingfan Liu,
Po-Hsu Lin, Qian Cai, Ram Pai, Randy Dunlap, Sandipan Das, Stephen
Rothwell, Tyrel Datwyler, Will Springer, Yury Norov, and Zheng Yongjun.

* tag 'powerpc-5.12-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: (188 commits)
  powerpc/perf: Adds support for programming of Thresholding in P10
  powerpc/pci: Remove unimplemented prototypes
  powerpc/uaccess: Merge raw_copy_to_user_allowed() into raw_copy_to_user()
  powerpc/uaccess: Merge __put_user_size_allowed() into __put_user_size()
  powerpc/uaccess: get rid of small constant size cases in raw_copy_{to,from}_user()
  powerpc/64: Fix stack trace not displaying final frame
  powerpc/time: Remove get_tbl()
  powerpc/time: Avoid using get_tbl()
  spi: mpc52xx: Avoid using get_tbl()
  powerpc/syscall: Avoid storing 'current' in another pointer
  powerpc/32: Handle bookE debugging in C in syscall entry/exit
  powerpc/syscall: Do not check unsupported scv vector on PPC32
  powerpc/32: Remove the counter in global_dbcr0
  powerpc/32: Remove verification of MSR_PR on syscall in the ASM entry
  powerpc/syscall: implement system call entry/exit logic in C for PPC32
  powerpc/32: Always save non volatile GPRs at syscall entry
  powerpc/syscall: Change condition to check MSR_RI
  powerpc/syscall: Save r3 in regs->orig_r3
  powerpc/syscall: Use is_compat_task()
  powerpc/syscall: Make interrupt.c buildable on PPC32
  ...

powerpc/syscall: Make interrupt.c buildable on PPC32

2021-02-11T12:35:10+00:00

To allow building interrupt.c on PPC32, ifdef out specific PPC64
code or use helpers which are available on both PP32 and PPC64

Modify Makefile to always build interrupt.o

Signed-off-by: Christophe Leroy 
Reviewed-by: Nicholas Piggin 
Signed-off-by: Michael Ellerman 
Link: https://lore.kernel.org/r/ba073ad67bd971a88ce331b65d6655523b54c794.1612796617.git.christophe.leroy@csgroup.eu

powerpc/syscall: Rename syscall_64.c into interrupt.c

2021-02-11T12:35:10+00:00

syscall_64.c will be reused almost as is for PPC32.

As this file also contains functions to handle other types
of interrupts rename it interrupt.c

Signed-off-by: Christophe Leroy 
Reviewed-by: Nicholas Piggin 
Signed-off-by: Michael Ellerman 
Link: https://lore.kernel.org/r/cddc2deaa8f049d3ec419738e69804934919b935.1612796617.git.christophe.leroy@csgroup.eu

powerpc/vdso: fix unnecessary rebuilds of vgettimeofday.o

2021-01-30T11:23:42+00:00

vgettimeofday.o is unnecessarily rebuilt. Adding it to 'targets' is not
enough to fix the issue. Kbuild is correctly rebuilding it because the
command line is changed.

PowerPC builds each vdso directory twice; first in vdso_prepare to
generate vdso{32,64}-offsets.h, second as part of the ordinary build
process to embed vdso{32,64}.so.dbg into the kernel.

The problem shows up when CONFIG_PPC_WERROR=y due to the following line
in arch/powerpc/Kbuild:

  subdir-ccflags-$(CONFIG_PPC_WERROR) := -Werror

In the preparation stage, Kbuild directly visits the vdso directories,
hence it does not inherit subdir-ccflags-y. In the second descend,
Kbuild adds -Werror, which results in the command line flipping
with/without -Werror.

It implies a potential danger; if a more critical flag that would impact
the resulted vdso, the offsets recorded in the headers might be different
from real offsets in the embedded vdso images.

Removing the unneeded second descend solves the problem.

Reported-by: Michael Ellerman 
Signed-off-by: Masahiro Yamada 
Signed-off-by: Michael Ellerman 
Link: https://lore.kernel.org/linuxppc-dev/87tuslxhry.fsf@mpe.ellerman.id.au/
Link: https://lore.kernel.org/r/20201223171142.707053-1-masahiroy@kernel.org