H_GetPerformanceCounterInfo (0xF080) hcall returns the counter data in
the result buffer. Result buffer has specific format defined in the PAPR
specification. One of the fields is counter offset and width of the
counter data returned.
Counter data are returned in a unsigned char array in big endian byte
order. To get the final counter data, the values must be left shifted
byte at a time. But commit 220a0c609a ("powerpc/perf: Add support for
the hv gpci (get performance counter info) interface") made the shifting
bitwise and also assumed little endian order. Because of that, hcall
counters values are reported incorrectly.
In particular this can lead to counters go backwards which messes up the
counter prev vs now calculation and leads to huge counter value
reporting:
#: perf stat -e hv_gpci/system_tlbie_count_and_time_tlbie_instructions_issued/
-C 0 -I 1000
time counts unit events
1.000078854 18,446,744,073,709,535,232 hv_gpci/system_tlbie_count_and_time_tlbie_instructions_issued/
2.000213293 0 hv_gpci/system_tlbie_count_and_time_tlbie_instructions_issued/
3.000320107 0 hv_gpci/system_tlbie_count_and_time_tlbie_instructions_issued/
4.000428392 0 hv_gpci/system_tlbie_count_and_time_tlbie_instructions_issued/
5.000537864 0 hv_gpci/system_tlbie_count_and_time_tlbie_instructions_issued/
6.000649087 0 hv_gpci/system_tlbie_count_and_time_tlbie_instructions_issued/
7.000760312 0 hv_gpci/system_tlbie_count_and_time_tlbie_instructions_issued/
8.000865218 16,448 hv_gpci/system_tlbie_count_and_time_tlbie_instructions_issued/
9.000978985 18,446,744,073,709,535,232 hv_gpci/system_tlbie_count_and_time_tlbie_instructions_issued/
10.001088891 16,384 hv_gpci/system_tlbie_count_and_time_tlbie_instructions_issued/
11.001201435 0 hv_gpci/system_tlbie_count_and_time_tlbie_instructions_issued/
12.001307937 18,446,744,073,709,535,232 hv_gpci/system_tlbie_count_and_time_tlbie_instructions_issued/
Fix the shifting logic to correct match the format, ie. read bytes in
big endian order.
Fixes: e4f226b158 ("powerpc/perf/hv-gpci: Increase request buffer size")
Cc: stable@vger.kernel.org # v4.6+
Reported-by: Nageswara R Sastry<rnsastry@linux.ibm.com>
Signed-off-by: Kajol Jain <kjain@linux.ibm.com>
Tested-by: Nageswara R Sastry<rnsastry@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210813082158.429023-1-kjain@linux.ibm.com
Commit a278e7ea60 ("powerpc: Fix compile issue with force DAWR")
selects the non-existing config PPC_DAWR_FORCE_ENABLE for config
KVM_BOOK3S_64_HANDLER. As this commit also introduces a config PPC_DAWR
and this config PPC_DAWR is selected with PPC if PPC64, there is no
need for any further select in the KVM_BOOK3S_64_HANDLER.
Remove an obsolete and unneeded select in config KVM_BOOK3S_64_HANDLER.
The issue was identified with ./scripts/checkkconfigsymbols.py.
Fixes: a278e7ea60 ("powerpc: Fix compile issue with force DAWR")
Signed-off-by: Lukas Bulwahn <lukas.bulwahn@gmail.com>
Reviewed-by: Daniel Axtens <dja@axtens.net>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210819113954.17515-2-lukas.bulwahn@gmail.com
CONFIG_MTD_PHYSMAP_OF is not longer enabled as it depends on
MTD_PHYSMAP which is not enabled.
This is a regression from commit 642b1e8dbe ("mtd: maps: Merge
physmap_of.c into physmap-core.c"), which added the extra dependency.
Add CONFIG_MTD_PHYSMAP=y so this stays in the config, as Christophe said
it is useful for build coverage.
Fixes: 642b1e8dbe ("mtd: maps: Merge physmap_of.c into physmap-core.c")
Signed-off-by: Joel Stanley <joel@jms.id.au>
Acked-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210817045407.2445664-3-joel@jms.id.au
When building this config there's a warning:
79⚠️ override: reassigning to symbol IPV6
Commit 9a1762a4a4 ("powerpc/8xx: Update mpc885_ads_defconfig to
improve CI") added CONFIG_IPV6=y, but left '# CONFIG_IPV6 is not set'
in.
IPV6 is default y, so remove both to clean up the build.
Fixes: 9a1762a4a4 ("powerpc/8xx: Update mpc885_ads_defconfig to improve CI")
Signed-off-by: Joel Stanley <joel@jms.id.au>
Acked-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210817045407.2445664-2-joel@jms.id.au
As reported by lkp, if NUMA=n we see a build error:
arch/powerpc/platforms/pseries/hotplug-cpu.c: In function 'pseries_cpu_hotplug_init':
arch/powerpc/platforms/pseries/hotplug-cpu.c:1022:8: error: 'node_to_cpumask_map' undeclared
1022 | node_to_cpumask_map[node]);
Use cpumask_of_node() which has an empty stub for NUMA=n, and when
NUMA=y does a lookup from node_to_cpumask_map[].
Fixes: bd1dd4c5f5 ("powerpc/pseries: Prevent free CPU ids being reused on another node")
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210816041032.2839343-1-mpe@ellerman.id.au
Object files used to link .tmp_vmlinux.kallsyms1 have many
R_PPC64_ADDR64 relocations in non-SHF_WRITE sections. There are many
text relocations (e.g. in .rela___ksymtab_gpl+* and .rela__mcount_loc
sections) in a -pie link and are disallowed by LLD:
ld.lld: error: can't create dynamic relocation R_PPC64_ADDR64 against local symbol in readonly segment; recompile object files with -fPIC or pass '-Wl,-z,notext' to allow text relocations in the output
>>> defined in arch/powerpc/kernel/head_64.o
>>> referenced by arch/powerpc/kernel/head_64.o:(__restart_table+0x10)
Newer GNU ld configured with "--enable-textrel-check=error" will report
an error as well:
$ ld-new -EL -m elf64lppc -pie ... -o .tmp_vmlinux.kallsyms1 ...
ld-new: read-only segment has dynamic relocations
Add "-z notext" to suppress the errors. Non-CONFIG_RELOCATABLE builds
use the default -no-pie mode and thus R_PPC64_ADDR64 relocations can be
resolved at link-time.
Reported-by: Itaru Kitayama <itaru.kitayama@riken.jp>
Co-developed-by: Bill Wendling <morbo@google.com>
Signed-off-by: Fangrui Song <maskray@google.com>
Signed-off-by: Bill Wendling <morbo@google.com>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210813200511.1905703-1-morbo@google.com
Using asm goto in __WARN_FLAGS() and WARN_ON() allows more
flexibility to GCC.
For that add an entry to the exception table so that
program_check_exception() knowns where to resume execution
after a WARNING.
Here are two exemples. The first one is done on PPC32 (which
benefits from the previous patch), the second is on PPC64.
unsigned long test(struct pt_regs *regs)
{
int ret;
WARN_ON(regs->msr & MSR_PR);
return regs->gpr[3];
}
unsigned long test9w(unsigned long a, unsigned long b)
{
if (WARN_ON(!b))
return 0;
return a / b;
}
Before the patch:
000003a8 <test>:
3a8: 81 23 00 84 lwz r9,132(r3)
3ac: 71 29 40 00 andi. r9,r9,16384
3b0: 40 82 00 0c bne 3bc <test+0x14>
3b4: 80 63 00 0c lwz r3,12(r3)
3b8: 4e 80 00 20 blr
3bc: 0f e0 00 00 twui r0,0
3c0: 80 63 00 0c lwz r3,12(r3)
3c4: 4e 80 00 20 blr
0000000000000bf0 <.test9w>:
bf0: 7c 89 00 74 cntlzd r9,r4
bf4: 79 29 d1 82 rldicl r9,r9,58,6
bf8: 0b 09 00 00 tdnei r9,0
bfc: 2c 24 00 00 cmpdi r4,0
c00: 41 82 00 0c beq c0c <.test9w+0x1c>
c04: 7c 63 23 92 divdu r3,r3,r4
c08: 4e 80 00 20 blr
c0c: 38 60 00 00 li r3,0
c10: 4e 80 00 20 blr
After the patch:
000003a8 <test>:
3a8: 81 23 00 84 lwz r9,132(r3)
3ac: 71 29 40 00 andi. r9,r9,16384
3b0: 40 82 00 0c bne 3bc <test+0x14>
3b4: 80 63 00 0c lwz r3,12(r3)
3b8: 4e 80 00 20 blr
3bc: 0f e0 00 00 twui r0,0
0000000000000c50 <.test9w>:
c50: 7c 89 00 74 cntlzd r9,r4
c54: 79 29 d1 82 rldicl r9,r9,58,6
c58: 0b 09 00 00 tdnei r9,0
c5c: 7c 63 23 92 divdu r3,r3,r4
c60: 4e 80 00 20 blr
c70: 38 60 00 00 li r3,0
c74: 4e 80 00 20 blr
In the first exemple, we see GCC doesn't need to duplicate what
happens after the trap.
In the second exemple, we see that GCC doesn't need to emit a test
and a branch in the likely path in addition to the trap.
We've got some WARN_ON() in .softirqentry.text section so it needs
to be added in the OTHER_TEXT_SECTIONS in modpost.c
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/389962b1b702e3c78d169e59bcfac56282889173.1618331882.git.christophe.leroy@csgroup.eu
powerpc BUG_ON() and WARN_ON() are based on using twnei instruction.
For catching simple conditions like a variable having value 0, this
is efficient because it does the test and the trap at the same time.
But most conditions used with BUG_ON or WARN_ON are more complex and
forces GCC to format the condition into a 0 or 1 value in a register.
This will usually require 2 to 3 instructions.
The most efficient solution would be to use __builtin_trap() because
GCC is able to optimise the use of the different trap instructions
based on the requested condition, but this is complex if not
impossible for the following reasons:
- __builtin_trap() is a non-recoverable instruction, so it can't be
used for WARN_ON
- Knowing which line of code generated the trap would require the
analysis of DWARF information. This is not a feature we have today.
As mentioned in commit 8d4fbcfbe0 ("Fix WARN_ON() on bitfield ops")
the way WARN_ON() is implemented is suboptimal. That commit also
mentions an issue with 'long long' condition. It fixed it for
WARN_ON() but the same problem still exists today with BUG_ON() on
PPC32. It will be fixed by using the generic implementation.
By using the generic implementation, gcc will naturally generate a
branch to the unconditional trap generated by BUG().
As modern powerpc implement zero-cycle branch,
that's even more efficient.
And for the functions using WARN_ON() and its return, the test
on return from WARN_ON() is now also used for the WARN_ON() itself.
On PPC64 we don't want it because we want to be able to use CFAR
register to track how we entered the code that trapped. The CFAR
register would be clobbered by the branch.
A simple test function:
unsigned long test9w(unsigned long a, unsigned long b)
{
if (WARN_ON(!b))
return 0;
return a / b;
}
Before the patch:
0000046c <test9w>:
46c: 7c 89 00 34 cntlzw r9,r4
470: 55 29 d9 7e rlwinm r9,r9,27,5,31
474: 0f 09 00 00 twnei r9,0
478: 2c 04 00 00 cmpwi r4,0
47c: 41 82 00 0c beq 488 <test9w+0x1c>
480: 7c 63 23 96 divwu r3,r3,r4
484: 4e 80 00 20 blr
488: 38 60 00 00 li r3,0
48c: 4e 80 00 20 blr
After the patch:
00000468 <test9w>:
468: 2c 04 00 00 cmpwi r4,0
46c: 41 82 00 0c beq 478 <test9w+0x10>
470: 7c 63 23 96 divwu r3,r3,r4
474: 4e 80 00 20 blr
478: 0f e0 00 00 twui r0,0
47c: 38 60 00 00 li r3,0
480: 4e 80 00 20 blr
So we see before the patch we need 3 instructions on the likely path
to handle the WARN_ON(). With the patch the trap goes on the unlikely
path.
See below the difference at the entry of system_call_exception where
we have several BUG_ON(), allthough less impressing.
With the patch:
00000000 <system_call_exception>:
0: 81 6a 00 84 lwz r11,132(r10)
4: 90 6a 00 88 stw r3,136(r10)
8: 71 60 00 02 andi. r0,r11,2
c: 41 82 00 70 beq 7c <system_call_exception+0x7c>
10: 71 60 40 00 andi. r0,r11,16384
14: 41 82 00 6c beq 80 <system_call_exception+0x80>
18: 71 6b 80 00 andi. r11,r11,32768
1c: 41 82 00 68 beq 84 <system_call_exception+0x84>
20: 94 21 ff e0 stwu r1,-32(r1)
24: 93 e1 00 1c stw r31,28(r1)
28: 7d 8c 42 e6 mftb r12
...
7c: 0f e0 00 00 twui r0,0
80: 0f e0 00 00 twui r0,0
84: 0f e0 00 00 twui r0,0
Without the patch:
00000000 <system_call_exception>:
0: 94 21 ff e0 stwu r1,-32(r1)
4: 93 e1 00 1c stw r31,28(r1)
8: 90 6a 00 88 stw r3,136(r10)
c: 81 6a 00 84 lwz r11,132(r10)
10: 69 60 00 02 xori r0,r11,2
14: 54 00 ff fe rlwinm r0,r0,31,31,31
18: 0f 00 00 00 twnei r0,0
1c: 69 60 40 00 xori r0,r11,16384
20: 54 00 97 fe rlwinm r0,r0,18,31,31
24: 0f 00 00 00 twnei r0,0
28: 69 6b 80 00 xori r11,r11,32768
2c: 55 6b 8f fe rlwinm r11,r11,17,31,31
30: 0f 0b 00 00 twnei r11,0
34: 7d 8c 42 e6 mftb r12
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/b286e07fb771a664b631cd07a40b09c06f26e64b.1618331881.git.christophe.leroy@csgroup.eu
The associativity details of the newly added resourced are collected from
the hypervisor via "ibm,configure-connector" rtas call. Update the numa
distance details of the newly added numa node after the above call.
Instead of updating NUMA distance every time we lookup a node id
from the associativity property, add helpers that can be used
during boot which does this only once. Also remove the distance
update from node id lookup helpers.
Currently, we duplicate parsing code for ibm,associativity and
ibm,associativity-lookup-arrays in the kernel. The associativity array provided
by these device tree properties are very similar and hence can use
a helper to parse the node id and numa distance details.
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210812132223.225214-4-aneesh.kumar@linux.ibm.com
In the numa=off kernel command-line configuration init_chip_info() loops
around the number of chips and attempts to copy the cpumask of that node
which is NULL for all iterations after the first chip.
Hence, store the cpu mask for each chip instead of derving cpumask from
node while populating the "chips" struct array and copy that to the
chips[i].mask
Fixes: 053819e0bf ("cpufreq: powernv: Handle throttling due to Pmax capping at chip level")
Cc: stable@vger.kernel.org # v4.3+
Reported-by: Shirisha Ganta <shirisha.ganta1@ibm.com>
Signed-off-by: Pratik R. Sampat <psampat@linux.ibm.com>
Reviewed-by: Gautham R. Shenoy <ego@linux.vnet.ibm.com>
[mpe: Rename goto label to out_free_chip_cpu_mask]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210728120500.87549-2-psampat@linux.ibm.com
