linux.git/arch/powerpc/kernel/misc_32.S, branch v5.6

powerpc/32: Split kexec low level code out of misc_32.S

2019-11-21T04:41:34+00:00

Almost half of misc_32.S is dedicated to kexec.
That's the relocation function for kexec.

Drop it into a dedicated kexec_relocate_32.S

Signed-off-by: Christophe Leroy 
Signed-off-by: Michael Ellerman 
Link: https://lore.kernel.org/r/e235973a1198195763afd3b6baffa548a83f4611.1572351221.git.christophe.leroy@c-s.fr

powerpc: Convert flush_icache_range & friends to C

2019-11-07T12:35:37+00:00

Similar to commit 22e9c88d486a
("powerpc/64: reuse PPC32 static inline flush_dcache_range()")
this patch converts the following ASM symbols to C:
    flush_icache_range()
    __flush_dcache_icache()
    __flush_dcache_icache_phys()

This was done as we discovered a long-standing bug where the length of the
range was truncated due to using a 32 bit shift instead of a 64 bit one.

By converting these functions to C, it becomes easier to maintain.

flush_dcache_icache_phys() retains a critical assembler section as we must
ensure there are no memory accesses while the data MMU is disabled
(authored by Christophe Leroy). Since this has no external callers, it has
also been made static, allowing the compiler to inline it within
flush_dcache_icache_page().

Signed-off-by: Alastair D'Silva 
Signed-off-by: Christophe Leroy 
Signed-off-by: Michael Ellerman 
[mpe: Minor fixups, don't export __flush_dcache_icache()]
Link: https://lore.kernel.org/r/20191104023305.9581-5-alastair@au1.ibm.com

powerpc/32: don't use CPU_FTR_COHERENT_ICACHE

2019-08-28T13:19:34+00:00

Only 601 and E200 have CPU_FTR_COHERENT_ICACHE.

Just use #ifdefs instead of feature fixup.

Signed-off-by: Christophe Leroy 
Signed-off-by: Michael Ellerman 
Link: https://lore.kernel.org/r/5f3e92ccd64d06477b27626f6007a9da3b8da157.1566834712.git.christophe.leroy@c-s.fr

powerpc/32: drop CPU_FTR_UNIFIED_ID_CACHE

2019-08-28T13:19:33+00:00

Only 601 and e200 have unified I/D cache.

Drop the feature and use CONFIG_PPC_BOOK3S_601 and CONFIG_E200.

Signed-off-by: Christophe Leroy 
Signed-off-by: Michael Ellerman 
Link: https://lore.kernel.org/r/b5902144266d2f4eed1ffea53915bd0245841e02.1566834712.git.christophe.leroy@c-s.fr

powerpc/32s: use CONFIG_PPC_BOOK3S_601 instead of reading PVR

2019-08-28T13:19:33+00:00

Use CONFIG_PPC_BOOK3S_601 instead of reading PVR to know if
it is a 601 or not.

Signed-off-by: Christophe Leroy 
Signed-off-by: Michael Ellerman 
Link: https://lore.kernel.org/r/909c26db9facd7fe454695b303f952e019dd9eda.1566834712.git.christophe.leroy@c-s.fr

powerpc/32: Add warning on misaligned copy_page() or clear_page()

2019-08-20T11:22:15+00:00

copy_page() and clear_page() expect page aligned destination, and
use dcbz instruction to clear entire cache lines based on the
assumption that the destination is cache aligned.

As shown during analysis of a bug in BTRFS filesystem, a misaligned
copy_page() can create bugs that are difficult to locate (see Link).

Add an explicit WARNING when copy_page() or clear_page() are called
with misaligned destination.

Signed-off-by: Christophe Leroy 
Signed-off-by: Michael Ellerman 
Link: https://bugzilla.kernel.org/show_bug.cgi?id=204371
Link: https://lore.kernel.org/r/c6cea38f90480268d439ca44a645647e260fff09.1565941808.git.christophe.leroy@c-s.fr

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152

2019-05-30T18:26:32+00:00

Based on 1 normalized pattern(s):

  this program is free software you can redistribute it and or modify
  it under the terms of the gnu general public license as published by
  the free software foundation either version 2 of the license or at
  your option any later version

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-or-later

has been chosen to replace the boilerplate/reference in 3029 file(s).

Signed-off-by: Thomas Gleixner 
Reviewed-by: Allison Randal 
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190527070032.746973796@linutronix.de
Signed-off-by: Greg Kroah-Hartman

powerpc/32: Remove CURRENT_THREAD_INFO and rename TI_CPU

2019-02-23T11:31:40+00:00

Now that thread_info is similar to task_struct, its address is in r2
so CURRENT_THREAD_INFO() macro is useless. This patch removes it.

This patch also moves the 'tovirt(r2, r2)' down just before the
reactivation of MMU translation, so that we keep the physical address
of 'current' in r2 until then. It avoids a few calls to tophys().

At the same time, as the 'cpu' field is not anymore in thread_info,
TI_CPU is renamed TASK_CPU by this patch.

It also allows to get rid of a couple of
'#ifdef CONFIG_VIRT_CPU_ACCOUNTING_NATIVE' as ACCOUNT_CPU_USER_ENTRY()
and ACCOUNT_CPU_USER_EXIT() are empty when
CONFIG_VIRT_CPU_ACCOUNTING_NATIVE is not defined.

Signed-off-by: Christophe Leroy 
[mpe: Fix a missed conversion of TI_CPU idle_6xx.S]
Signed-off-by: Michael Ellerman

powerpc: regain entire stack space

2019-02-23T11:31:40+00:00

thread_info is not anymore in the stack, so the entire stack
can now be used.

There is also no risk anymore of corrupting task_cpu(p) with a
stack overflow so the patch removes the test.

When doing this, an explicit test for NULL stack pointer is
needed in validate_sp() as it is not anymore implicitely covered
by the sizeof(thread_info) gap.

In the meantime, with the previous patch all pointers to the stacks
are not anymore pointers to thread_info so this patch changes them
to void*

Signed-off-by: Christophe Leroy 
Signed-off-by: Michael Ellerman

powerpc: Don't use CURRENT_THREAD_INFO to find the stack

2019-02-23T11:31:40+00:00

A few places use CURRENT_THREAD_INFO, or the C version, to find the
stack. This will no longer work with THREAD_INFO_IN_TASK so change
them to find the stack in other ways.

Signed-off-by: Christophe Leroy 
Reviewed-by: Nicholas Piggin 
[mpe: Split out of larger patch]
Signed-off-by: Michael Ellerman