linux.git/arch/powerpc/kernel/prom.c, branch v5.14

powerpc: Remove klimit

2021-06-24T14:07:10+00:00

klimit is a global variable initialised at build time with the
value of _end.

This variable is never modified, so _end symbol can be used directly.

Remove klimit.

Signed-off-by: Christophe Leroy 
Reviewed-by: Kefeng Wang 
Signed-off-by: Michael Ellerman 
Link: https://lore.kernel.org/r/9fa9ba6807c17f93f35a582c199c646c4a8bfd9c.1622800638.git.christophe.leroy@csgroup.eu

powerpc/smp: Cache CPU to chip lookup

2021-04-17T00:40:51+00:00

On systems with large CPUs per node, even with the filtered matching of
related CPUs, there can be large number of calls to cpu_to_chip_id for
the same CPU. For example with 4096 vCPU, 1 node QEMU configuration,
with 4 threads per core, system could be see upto 1024 calls to
cpu_to_chip_id() for the same CPU. On a given system, cpu_to_chip_id()
for a given CPU would always return the same. Hence cache the result in
a lookup table for use in subsequent calls.

Since all CPUs sharing the same core will belong to the same chip, the
lookup_table has an entry for one CPU per core.  chip_id_lookup_table is
not being freed and would be used on subsequent CPU online post CPU
offline.

Reported-by: Daniel Henrique Barboza 
Suggested-by: Michael Ellerman 
Signed-off-by: Srikar Dronamraju 
Tested-by: Daniel Henrique Barboza 
Signed-off-by: Michael Ellerman 
Link: https://lore.kernel.org/r/20210415120934.232271-4-srikar@linux.vnet.ibm.com

powerpc/prom: Mark identical_pvr_fixup as __init

2021-03-24T03:09:30+00:00

If identical_pvr_fixup() is not inlined, there are two modpost warnings:

WARNING: modpost: vmlinux.o(.text+0x54e8): Section mismatch in reference
from the function identical_pvr_fixup() to the function
.init.text:of_get_flat_dt_prop()
The function identical_pvr_fixup() references
the function __init of_get_flat_dt_prop().
This is often because identical_pvr_fixup lacks a __init
annotation or the annotation of of_get_flat_dt_prop is wrong.

WARNING: modpost: vmlinux.o(.text+0x551c): Section mismatch in reference
from the function identical_pvr_fixup() to the function
.init.text:identify_cpu()
The function identical_pvr_fixup() references
the function __init identify_cpu().
This is often because identical_pvr_fixup lacks a __init
annotation or the annotation of identify_cpu is wrong.

identical_pvr_fixup() calls two functions marked as __init and is only
called by a function marked as __init so it should be marked as __init
as well. At the same time, remove the inline keywork as it is not
necessary to inline this function. The compiler is still free to do so
if it feels it is worthwhile since commit 889b3c1245de ("compiler:
remove CONFIG_OPTIMIZE_INLINING entirely").

Fixes: 14b3d926a22b ("[POWERPC] 4xx: update 440EP(x)/440GR(x) identical PVR issue workaround")
Signed-off-by: Nathan Chancellor 
Signed-off-by: Michael Ellerman 
Link: https://github.com/ClangBuiltLinux/linux/issues/1316
Link: https://lore.kernel.org/r/20210302200829.2680663-1-nathan@kernel.org

powerpc: remove unneeded semicolons

2021-02-08T13:10:50+00:00

Remove superfluous semicolons after function definitions.

Signed-off-by: Chengyang Fan 
Signed-off-by: Michael Ellerman 
Link: https://lore.kernel.org/r/20210125095338.1719405-1-cy.fan@huawei.com

powerpc/feature: Remove CPU_FTR_NODSISRALIGN

2020-12-03T14:01:34+00:00

CPU_FTR_NODSISRALIGN has not been used since
commit 31bfdb036f12 ("powerpc: Use instruction emulation
infrastructure to handle alignment faults")

Remove it.

Signed-off-by: Christophe Leroy 
Signed-off-by: Michael Ellerman 
Link: https://lore.kernel.org/r/05d98136b24bbf11525445414bb18cffe2724f48.1602587470.git.christophe.leroy@csgroup.eu

powerpc/mm/book3s: Split radix and hash MAX_PHYSMEM limit

2020-09-15T12:13:22+00:00

MAX_PHYSMEM #define is used along with sparsemem to determine the SECTION_SHIFT
value. Powerpc also uses the same value to limit the max memory enabled on the
system. With 4K PAGE_SIZE and hash translation mode, we want to limit the max
memory enabled to 64TB due to page table size restrictions. However, with
radix translation, we don't have these restrictions. Hence split the radix
and hash MA_PHYSMEM limit and use different limit for each of them.

Signed-off-by: Aneesh Kumar K.V 
Signed-off-by: Michael Ellerman 
Link: https://lore.kernel.org/r/20200608070904.387440-4-aneesh.kumar@linux.ibm.com

powerpc/drmem: Make LMB walk a bit more flexible

2020-07-29T13:47:54+00:00

Currently, numa & prom are the only users of drmem LMB walk code.
Loading kdump with kexec_file also needs to walk the drmem LMBs to
setup the usable memory ranges for kdump kernel. But there are couple
of issues in using the code as is. One, walk_drmem_lmb() code is built
into the .init section currently, while kexec_file needs it later.
Two, there is no scope to pass data to the callback function for
processing and/or erroring out on certain conditions.

Fix that by, moving drmem LMB walk code out of .init section, adding
scope to pass data to the callback function and bailing out when an
error is encountered in the callback function.

Signed-off-by: Hari Bathini 
Tested-by: Pingfan Liu 
Reviewed-by: Thiago Jung Bauermann 
Signed-off-by: Michael Ellerman 
Link: https://lore.kernel.org/r/159602282727.575379.3979857013827701828.stgit@hbathini

powerpc/watchpoint: Set CPU_FTR_DAWR1 based on pa-features bit

2020-07-26T13:34:19+00:00

As per the PAPR, bit 0 of byte 64 in pa-features property indicates
availability of 2nd DAWR registers. i.e. If this bit is set, 2nd
DAWR is present, otherwise not. Host generally uses "cpu-features",
which masks "pa-features". But "cpu-features" are still not used for
guests and thus this change is mostly applicable for guests only.

Signed-off-by: Ravi Bangoria 
Tested-by: Jordan Niethe 
Signed-off-by: Michael Ellerman 
Link: https://lore.kernel.org/r/20200723090813.303838-7-ravi.bangoria@linux.ibm.com

powerpc/book3s64/pkeys: Add MMU_FTR_PKEY

2020-07-20T12:57:58+00:00

Parse storage keys related device tree entry in early_init_devtree
and enable MMU feature MMU_FTR_PKEY if pkeys are supported.

MMU feature is used instead of CPU feature because this enables us
to group MMU_FTR_KUAP and MMU_FTR_PKEY in asm feature fixup code.

Signed-off-by: Aneesh Kumar K.V 
Signed-off-by: Michael Ellerman 
Link: https://lore.kernel.org/r/20200709032946.881753-14-aneesh.kumar@linux.ibm.com

powerpc/prom: Enable Radix GTSE in cpu pa-features

2020-07-20T12:56:40+00:00

When '029ab30b4c0a ("powerpc/mm: Enable radix GTSE only if supported.")'
made GTSE an MMU feature, it was enabled by default in
powerpc-cpu-features but was missed in pa-features. This causes random
memory corruption during boot of PowerNV kernels where
CONFIG_PPC_DT_CPU_FTRS isn't enabled.

Fixes: 029ab30b4c0a ("powerpc/mm: Enable radix GTSE only if supported.")
Reported-by: Qian Cai 
Signed-off-by: Nicholas Piggin 
Signed-off-by: Bharata B Rao 
[mpe: Unwrap long line]
Signed-off-by: Michael Ellerman 
Link: https://lore.kernel.org/r/20200720044258.863574-1-bharata@linux.ibm.com