Commit Graph

935158 Commits

Author SHA1 Message Date
Jason A. Donenfeld
521fd61c84 security/keys: rewrite big_key crypto to use library interface
A while back, I noticed that the crypto and crypto API usage in big_keys
were entirely broken in multiple ways, so I rewrote it. Now, I'm
rewriting it again, but this time using the simpler ChaCha20Poly1305
library function. This makes the file considerably more simple; the
diffstat alone should justify this commit. It also should be faster,
since it no longer requires a mutex around the "aead api object" (nor
allocations), allowing us to encrypt multiple items in parallel. We also
benefit from being able to pass any type of pointer, so we can get rid
of the ridiculously complex custom page allocator that big_key really
doesn't need.

[DH: Change the select CRYPTO_LIB_CHACHA20POLY1305 to a depends on as
 select doesn't propagate and the build can end up with an =y dependending
 on some =m pieces.

 The depends on CRYPTO also had to be removed otherwise the configurator
 complains about a recursive dependency.]

Cc: Andy Lutomirski <luto@kernel.org>
Cc: Greg KH <gregkh@linuxfoundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: kernel-hardening@lists.openwall.com
Reviewed-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Signed-off-by: David Howells <dhowells@redhat.com>
2020-06-02 17:22:31 +01:00
Gustavo A. R. Silva
2ce113fa52 KEYS: Replace zero-length array with flexible-array
The current codebase makes use of the zero-length array language
extension to the C90 standard, but the preferred mechanism to declare
variable-length types such as these ones is a flexible array member[1][2],
introduced in C99:

struct foo {
        int stuff;
        struct boo array[];
};

By making use of the mechanism above, we will get a compiler warning
in case the flexible array does not occur last in the structure, which
will help us prevent some kind of undefined behavior bugs from being
inadvertently introduced[3] to the codebase from now on.

Also, notice that, dynamic memory allocations won't be affected by
this change:

"Flexible array members have incomplete type, and so the sizeof operator
may not be applied. As a quirk of the original implementation of
zero-length arrays, sizeof evaluates to zero."[1]

sizeof(flexible-array-member) triggers a warning because flexible array
members have incomplete type[1]. There are some instances of code in
which the sizeof operator is being incorrectly/erroneously applied to
zero-length arrays and the result is zero. Such instances may be hiding
some bugs. So, this work (flexible-array member conversions) will also
help to get completely rid of those sorts of issues.

This issue was found with the help of Coccinelle.

[1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html
[2] https://github.com/KSPP/linux/issues/21
[3] commit 7649773293 ("cxgb3/l2t: Fix undefined behaviour")

Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
2020-06-02 17:22:31 +01:00
Ben Boeckel
352780b61e Documentation: security: core.rst: add missing argument
This argument was just never documented in the first place.

Signed-off-by: Ben Boeckel <mathstuf@gmail.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
2020-06-02 17:22:31 +01:00
Kefeng Wang
b3e2d20973 rcuperf: Fix printk format warning
Using "%zu" to fix following warning,
kernel/rcu/rcuperf.c: In function ‘kfree_perf_init’:
include/linux/kern_levels.h:5:18: warning: format ‘%lu’ expects argument of type ‘long unsigned int’, but argument 2 has type ‘unsigned int’ [-Wformat=]

Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2020-06-02 08:41:37 -07:00
Sebastian Reichel
972eabb97a Revert "power: supply: sbs-battery: simplify read_read_string_data"
The commit is a nice cleanup, but breaks booting on exynos5 based
chromebooks. It's seems to come down to exynos5's i2c driver not
implementing I2C_FUNC_SMBUS_READ_BLOCK_DATA. It's not yet clear
why that breaks boot / massively slows it down when userspace
starts, so revert the problematic patch.

This reverts commit c4b12a2f3f.

Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>
2020-06-02 17:08:33 +02:00
Sebastian Reichel
cf1eb321d1 Revert "power: supply: sbs-battery: add PEC support"
This depends on the simplification of sbs_read_string_data, which
breaks booting exynos5 based chromebooks. More investigation is
required, so this patch and the simplification patch are reverted
for this merge window.

Note, that this is only a partial revert, since sbs_update_presence()
has not been removed. It is also required for the charger broadcast
disabling.

This reverts commit 79bcd5a4a6.

Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>
2020-06-02 16:59:08 +02:00
Aurelien Aptel
5f68ea4aa9 cifs: multichannel: move channel selection in function
This commit moves channel picking code in separate function.

Signed-off-by: Aurelien Aptel <aaptel@suse.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2020-06-02 09:58:41 -05:00
Steve French
bbbf9eafbf cifs: fix minor typos in comments and log messages
Fix four minor typos in comments and log messages

Signed-off-by: Steve French <stfrench@microsoft.com>
Reviewed-by: Aurelien Aptel <aaptel@suse.com>
2020-06-02 09:58:30 -05:00
Steve French
3563a6f468 smb3: minor update to compression header definitions
MS-SMB2 specification was updated in March.  Make minor additions
and corrections to compression related definitions in smb2pdu.h

Signed-off-by: Steve French <stfrench@microsoft.com>
Reviewed-by: Aurelien Aptel <aaptel@suse.com>
2020-06-02 09:58:17 -05:00
Wei Li
c893de12e1 kdb: Remove the misfeature 'KDBFLAGS'
Currently, 'KDBFLAGS' is an internal variable of kdb, it is combined
by 'KDBDEBUG' and state flags. It will be shown only when 'KDBDEBUG'
is set, and the user can define an environment variable named 'KDBFLAGS'
too. These are puzzling indeed.

After communication with Daniel, it seems that 'KDBFLAGS' is a misfeature.
So let's replace 'KDBFLAGS' with 'KDBDEBUG' to just show the value we
wrote into. After this modification, we can use `md4c1 kdb_flags` instead,
to observe the state flags.

Suggested-by: Daniel Thompson <daniel.thompson@linaro.org>
Signed-off-by: Wei Li <liwei391@huawei.com>
Link: https://lore.kernel.org/r/20200521072125.21103-1-liwei391@huawei.com
[daniel.thompson@linaro.org: Make kdb_flags unsigned to avoid arithmetic
right shift]
Signed-off-by: Daniel Thompson <daniel.thompson@linaro.org>
2020-06-02 15:15:46 +01:00
Douglas Anderson
1b310030bb kdb: Cleanup math with KDB_CMD_HISTORY_COUNT
From code inspection the math in handle_ctrl_cmd() looks super sketchy
because it subjects -1 from cmdptr and then does a "%
KDB_CMD_HISTORY_COUNT".  It turns out that this code works because
"cmdptr" is unsigned and KDB_CMD_HISTORY_COUNT is a nice power of 2.
Let's make this a little less sketchy.

This patch should be a no-op.

Signed-off-by: Douglas Anderson <dianders@chromium.org>
Link: https://lore.kernel.org/r/20200507161125.1.I2cce9ac66e141230c3644b8174b6c15d4e769232@changeid
Reviewed-by: Sumit Garg <sumit.garg@linaro.org>
Signed-off-by: Daniel Thompson <daniel.thompson@linaro.org>
2020-06-02 15:15:46 +01:00
Sumit Garg
195867ffea serial: amba-pl011: Support kgdboc_earlycon
Implement the read() function in the early console driver. With
recently added kgdboc_earlycon feature, this allows you to use kgdb
to debug fairly early into the system boot.

We only bother implementing this if polling is enabled since kgdb can't
be enabled without that.

Signed-off-by: Sumit Garg <sumit.garg@linaro.org>
Reviewed-by: Douglas Anderson <dianders@chromium.org>
Reviewed-by: Daniel Thompson <daniel.thompson@linaro.org>
Signed-off-by: Douglas Anderson <dianders@chromium.org>
Link: https://lore.kernel.org/r/20200507130644.v4.12.I8ee0811f0e0816dd8bfe7f2f5540b3dba074fae8@changeid
Signed-off-by: Daniel Thompson <daniel.thompson@linaro.org>
2020-06-02 15:15:46 +01:00
Douglas Anderson
c5e7467d92 serial: 8250_early: Support kgdboc_earlycon
Implement the read() function in the early console driver.  With
recent kgdb patches this allows you to use kgdb to debug fairly early
into the system boot.

We only bother implementing this if polling is enabled since kgdb
can't be enabled without that.

Signed-off-by: Douglas Anderson <dianders@chromium.org>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Daniel Thompson <daniel.thompson@linaro.org>
Link: https://lore.kernel.org/r/20200507130644.v4.11.I8f668556c244776523320a95b09373a86eda11b7@changeid
Signed-off-by: Daniel Thompson <daniel.thompson@linaro.org>
2020-06-02 15:15:46 +01:00
Douglas Anderson
205b5bdda2 serial: qcom_geni_serial: Support kgdboc_earlycon
Implement the read() function in the early console driver.  With
recent kgdb patches this allows you to use kgdb to debug fairly early
into the system boot.

We only bother implementing this if polling is enabled since kgdb
can't be enabled without that.

Signed-off-by: Douglas Anderson <dianders@chromium.org>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Link: https://lore.kernel.org/r/20200507130644.v4.10.If2deff9679a62c1ce1b8f2558a8635dc837adf8c@changeid
Signed-off-by: Daniel Thompson <daniel.thompson@linaro.org>
2020-06-02 15:15:46 +01:00
Daniel Thompson
a4912303ac serial: kgdboc: Allow earlycon initialization to be deferred
Currently there is no guarantee that an earlycon will be initialized
before kgdboc tries to adopt it. Almost the opposite: on systems
with ACPI then if earlycon has no arguments then it is guaranteed that
earlycon will not be initialized.

This patch mitigates the problem by giving kgdboc_earlycon a second
chance during console_init(). This isn't quite as good as stopping during
early parameter parsing but it is still early in the kernel boot.

Signed-off-by: Daniel Thompson <daniel.thompson@linaro.org>
Link: https://lore.kernel.org/r/20200430161741.1832050-1-daniel.thompson@linaro.org
Reviewed-by: Douglas Anderson <dianders@chromium.org>
2020-06-02 15:15:45 +01:00
Douglas Anderson
f71fc3bc7b Documentation: kgdboc: Document new kgdboc_earlycon parameter
The recent patch ("kgdboc: Add kgdboc_earlycon to support early kgdb
using boot consoles") adds a new kernel command line parameter.
Document it.

Note that the patch adding the feature does some comparing/contrasting
of "kgdboc_earlycon" vs. the existing "ekgdboc".  See that patch for
more details, but briefly "ekgdboc" can be used _instead_ of "kgdboc"
and just makes "kgdboc" do its normal initialization early (only works
if your tty driver is already ready).  The new "kgdboc_earlycon" works
in combination with "kgdboc" and is backed by boot consoles.

Signed-off-by: Douglas Anderson <dianders@chromium.org>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Daniel Thompson <daniel.thompson@linaro.org>
Link: https://lore.kernel.org/r/20200507130644.v4.9.I7d5eb42c6180c831d47aef1af44d0b8be3fac559@changeid
Signed-off-by: Daniel Thompson <daniel.thompson@linaro.org>
2020-06-02 15:15:45 +01:00
Douglas Anderson
b1350132fe kgdb: Don't call the deinit under spinlock
When I combined kgdboc_earlycon with an inflight patch titled ("soc:
qcom-geni-se: Add interconnect support to fix earlycon crash") [1]
things went boom.  Specifically I got a crash during the transition
between kgdboc_earlycon and the main kgdboc that looked like this:

Call trace:
 __schedule_bug+0x68/0x6c
 __schedule+0x75c/0x924
 schedule+0x8c/0xbc
 schedule_timeout+0x9c/0xfc
 do_wait_for_common+0xd0/0x160
 wait_for_completion_timeout+0x54/0x74
 rpmh_write_batch+0x1fc/0x23c
 qcom_icc_bcm_voter_commit+0x1b4/0x388
 qcom_icc_set+0x2c/0x3c
 apply_constraints+0x5c/0x98
 icc_set_bw+0x204/0x3bc
 icc_put+0x30/0xf8
 geni_remove_earlycon_icc_vote+0x6c/0x9c
 qcom_geni_serial_earlycon_exit+0x10/0x1c
 kgdboc_earlycon_deinit+0x38/0x58
 kgdb_register_io_module+0x11c/0x194
 configure_kgdboc+0x108/0x174
 kgdboc_probe+0x38/0x60
 platform_drv_probe+0x90/0xb0
 really_probe+0x130/0x2fc
 ...

The problem was that we were holding the "kgdb_registration_lock"
while calling into code that didn't expect to be called in spinlock
context.

Let's slightly defer when we call the deinit code so that it's not
done under spinlock.

NOTE: this does mean that the "deinit" call of the old kgdb IO module
is now made _after_ the init of the new IO module, but presumably
that's OK.

[1] https://lkml.kernel.org/r/1588919619-21355-3-git-send-email-akashast@codeaurora.org

Fixes: 220995622d ("kgdboc: Add kgdboc_earlycon to support early kgdb using boot consoles")
Signed-off-by: Douglas Anderson <dianders@chromium.org>
Link: https://lore.kernel.org/r/20200526142001.1.I523dc33f96589cb9956f5679976d402c8cda36fa@changeid
[daniel.thompson@linaro.org: Resolved merge issues by hand]
Signed-off-by: Daniel Thompson <daniel.thompson@linaro.org>
2020-06-02 15:15:45 +01:00
Douglas Anderson
1feb48baf2 kgdboc: Disable all the early code when kgdboc is a module
When kgdboc is compiled as a module all of the "ekgdboc" and
"kgdb_earlycon" code isn't useful and, in fact, breaks compilation.
This is because early_param() isn't defined for modules and that's how
this code gets configured.

It turns out that this was broken by commit eae3e19ca9 ("kgdboc:
Remove useless #ifdef CONFIG_KGDB_SERIAL_CONSOLE in kgdboc") and then
made worse by commit 220995622d ("kgdboc: Add kgdboc_earlycon to
support early kgdb using boot consoles").  I guess the #ifdef wasn't
so useless, even if it wasn't obvious why it was useful.  When kgdboc
was compiled as a module only "CONFIG_KGDB_SERIAL_CONSOLE_MODULE" was
defined, not "CONFIG_KGDB_SERIAL_CONSOLE".  That meant that the old
module.

Let's basically do the same thing that the old code (pre-removal of
the #ifdef) did but use "IS_BUILTIN(CONFIG_KGDB_SERIAL_CONSOLE)" to
make it more obvious what the point of the check is.  We'll fix
kgdboc_earlycon in a similar way.

Fixes: 220995622d ("kgdboc: Add kgdboc_earlycon to support early kgdb using boot consoles")
Fixes: eae3e19ca9 ("kgdboc: Remove useless #ifdef CONFIG_KGDB_SERIAL_CONSOLE in kgdboc")
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Douglas Anderson <dianders@chromium.org>
Link: https://lore.kernel.org/r/20200519084345.1.I91670accc8a5ddabab227eb63bb4ad3e2e9d2b58@changeid
Signed-off-by: Daniel Thompson <daniel.thompson@linaro.org>
2020-06-02 15:15:45 +01:00
Tiezhu Yang
3e9b26dc22 perf tools: Remove some duplicated includes
There exists some duplicated includes in tools/perf, remove them.

Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: xuefeng li <lixuefeng@loongson.cn>
Link: http://lore.kernel.org/lkml/1591071304-19338-2-git-send-email-yangtiezhu@loongson.cn
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2020-06-02 11:09:41 -03:00
Adrian Hunter
0affd0e526 perf symbols: Fix kernel maps for kcore and eBPF
Adjust 'map->pgoff' also when moving a map's start address.

Example with v5.4.34 based kernel:

  Before:

    $ sudo tools/perf/perf record -a --kcore -e intel_pt//k sleep 1
    [ perf record: Woken up 1 times to write data ]
    [ perf record: Captured and wrote 1.958 MB perf.data ]
    $ sudo tools/perf/perf script --itrace=e >/dev/null
    Warning:
    961 instruction trace errors

  After:

    $ sudo tools/perf/perf script --itrace=e >/dev/null
    $

Committer testing:

  # uname -a
  Linux seventh 5.6.10-100.fc30.x86_64 #1 SMP Mon May 4 15:36:44 UTC 2020 x86_64 x86_64 x86_64 GNU/Linux
  #

Before:

  # perf record -a --kcore -e intel_pt//k sleep 1
  [ perf record: Woken up 1 times to write data ]
  [ perf record: Captured and wrote 0.923 MB perf.data ]
  # perf script --itrace=e >/dev/null
  Warning:
  295 instruction trace errors
  #

After:

  # perf record -a --kcore -e intel_pt//k sleep 1
  [ perf record: Woken up 1 times to write data ]
  [ perf record: Captured and wrote 0.919 MB perf.data ]
  # perf script --itrace=e >/dev/null
  #

Fixes: fb5a88d413 ("perf tools: Preserve eBPF maps when loading kcore")
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: stable@vger.kernel.org
Link: http://lore.kernel.org/lkml/20200602112505.1406-1-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2020-06-02 11:05:37 -03:00
Arnaldo Carvalho de Melo
3b1f47d6e7 tools arch x86: Sync the msr-index.h copy with the kernel sources
To pick up the changes in:

  5cde265384 ("perf/x86/rapl: Add AMD Fam17h RAPL support")

Addressing this tools/perf build warning:

  Warning: Kernel ABI header at 'tools/arch/x86/include/asm/msr-index.h' differs from latest version at 'arch/x86/include/asm/msr-index.h'
  diff -u tools/arch/x86/include/asm/msr-index.h arch/x86/include/asm/msr-index.h

With this one will be able to use these new AMD MSRs in filters, by
name, e.g.:

   # perf trace -e msr:* --filter="msr==AMD_PKG_ENERGY_STATUS || msr==AMD_RAPL_POWER_UNIT"

Just like it is now possible with other MSRs:

  [root@five ~]# uname -a
  Linux five 5.5.17-200.fc31.x86_64 #1 SMP Mon Apr 13 15:29:42 UTC 2020 x86_64 x86_64 x86_64 GNU/Linux
  [root@five ~]# grep 'model name' -m1 /proc/cpuinfo
  model name	: AMD Ryzen 5 3600X 6-Core Processor
  [root@five ~]#
  [root@five ~]# perf trace -e msr:*/max-stack=16/ --filter="msr==AMD_PERF_CTL" --max-events=2
       0.000 kworker/1:1-ev/2327824 msr:write_msr(msr: AMD_PERF_CTL, val: 2)
                                         do_trace_write_msr ([kernel.kallsyms])
                                         do_trace_write_msr ([kernel.kallsyms])
                                         [0xffffffffc01d71c3] ([acpi_cpufreq])
                                         [0] ([unknown])
                                         __cpufreq_driver_target ([kernel.kallsyms])
                                         od_dbs_update ([kernel.kallsyms])
                                         dbs_work_handler ([kernel.kallsyms])
                                         process_one_work ([kernel.kallsyms])
                                         worker_thread ([kernel.kallsyms])
                                         kthread ([kernel.kallsyms])
                                         ret_from_fork ([kernel.kallsyms])
       8.597 kworker/2:2-ev/2338099 msr:write_msr(msr: AMD_PERF_CTL, val: 2)
                                         do_trace_write_msr ([kernel.kallsyms])
                                         do_trace_write_msr ([kernel.kallsyms])
                                         [0] ([unknown])
                                         [0] ([unknown])
                                         __cpufreq_driver_target ([kernel.kallsyms])
                                         od_dbs_update ([kernel.kallsyms])
                                         dbs_work_handler ([kernel.kallsyms])
                                         process_one_work ([kernel.kallsyms])
                                         worker_thread ([kernel.kallsyms])
                                         kthread ([kernel.kallsyms])
                                         ret_from_fork ([kernel.kallsyms])
  [root@five ~]#

Longer explanation with what happens in the perf build process,
automatically after this is made in synch with the kernel sources:

  $ make -C tools/perf O=/tmp/build/perf install-bin
  <SNIP>
  Warning: Kernel ABI header at 'tools/arch/x86/include/asm/msr-index.h' differs from latest version at 'arch/x86/include/asm/msr-index.h'
  diff -u tools/arch/x86/include/asm/msr-index.h arch/x86/include/asm/msr-index.h
  <SNIP>
  make: Leaving directory '/home/acme/git/perf/tools/perf'
  $
  $ tools/perf/trace/beauty/tracepoints/x86_msr.sh > before
  $
  $ diff -u tools/arch/x86/include/asm/msr-index.h arch/x86/include/asm/msr-index.h
  --- tools/arch/x86/include/asm/msr-index.h	2020-06-02 10:46:36.217782288 -0300
  +++ arch/x86/include/asm/msr-index.h	2020-05-28 10:41:23.313794627 -0300
  @@ -301,6 +301,9 @@
   #define MSR_PP1_ENERGY_STATUS		0x00000641
   #define MSR_PP1_POLICY			0x00000642

  +#define MSR_AMD_PKG_ENERGY_STATUS	0xc001029b
  +#define MSR_AMD_RAPL_POWER_UNIT		0xc0010299
  +
   /* Config TDP MSRs */
   #define MSR_CONFIG_TDP_NOMINAL		0x00000648
   #define MSR_CONFIG_TDP_LEVEL_1		0x00000649
  $ cp arch/x86/include/asm/msr-index.h tools/arch/x86/include/asm/msr-index.h
  $
  $ make -C tools/perf O=/tmp/build/perf install-bin
  <SNIP>
    CC       /tmp/build/perf/trace/beauty/tracepoints/x86_msr.o
    LD       /tmp/build/perf/trace/beauty/tracepoints/perf-in.o
    LD       /tmp/build/perf/trace/beauty/perf-in.o
    LD       /tmp/build/perf/perf-in.o
    LINK     /tmp/build/perf/perf
  <SNIP>
  make: Leaving directory '/home/acme/git/perf/tools/perf'
  $
  $ tools/perf/trace/beauty/tracepoints/x86_msr.sh > after
  $ diff -u before after
  --- before	2020-06-02 10:47:08.486334348 -0300
  +++ after	2020-06-02 10:47:33.075008948 -0300
  @@ -286,6 +286,8 @@
   	[0xc0010240 - x86_AMD_V_KVM_MSRs_offset] = "F15H_NB_PERF_CTL",
   	[0xc0010241 - x86_AMD_V_KVM_MSRs_offset] = "F15H_NB_PERF_CTR",
   	[0xc0010280 - x86_AMD_V_KVM_MSRs_offset] = "F15H_PTSC",
  +	[0xc0010299 - x86_AMD_V_KVM_MSRs_offset] = "AMD_RAPL_POWER_UNIT",
  +	[0xc001029b - x86_AMD_V_KVM_MSRs_offset] = "AMD_PKG_ENERGY_STATUS",
   	[0xc00102f0 - x86_AMD_V_KVM_MSRs_offset] = "AMD_PPIN_CTL",
   	[0xc00102f1 - x86_AMD_V_KVM_MSRs_offset] = "AMD_PPIN",
   };
  $

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Wang Nan <wangnan0@huawei.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2020-06-02 10:57:59 -03:00
Thierry Reding
d741cb045c MAINTAINERS: Add Lee Jones as reviewer for the PWM subsystem
Lee has kindly offered his help in sharing the patch review workload for
the PWM subsystem. If this works out well between Lee, Uwe and myself it
may be a good idea to maintain the subsystem as a group.

Acked-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2020-06-02 15:50:53 +02:00
Uwe Kleine-König
aef1a3799b pwm: imx27: Fix rounding behavior
To not trigger the warnings provided by CONFIG_PWM_DEBUG

 - use up-rounding in .get_state()
 - don't divide by the result of a division
 - don't use the rounded counter value for the period length to calculate
   the counter value for the duty cycle

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2020-06-02 15:50:52 +02:00
Rasmus Villemoes
cad0f29606 pwm: rockchip: Simplify rockchip_pwm_get_state()
The way state->enabled is computed is rather convoluted and hard to
read - both branches of the if() actually do the exact same thing. So
remove the if(), and further simplify "<boolean condition> ? true :
false" to "<boolean condition>".

Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2020-06-02 15:50:52 +02:00
Navid Emamdoost
ca162ce981 pwm: img: Call pm_runtime_put() in pm_runtime_get_sync() failed case
Even in failed case of pm_runtime_get_sync(), the usage_count is
incremented. In order to keep the usage_count with correct value call
appropriate pm_runtime_put().

Signed-off-by: Navid Emamdoost <navid.emamdoost@gmail.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2020-06-02 15:50:51 +02:00
Joonas Lahtinen
f8665d797b Merge tag 'gvt-next-fixes-2020-05-28' of https://github.com/intel/gvt-linux into drm-intel-next-fixes
gvt-next-fixes-2020-05-28

- Fix one clang warning on debug only function (Nathan)
- Use ARRAY_SIZE for coccicheck warn (Aishwarya)

Signed-off-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
From: Zhenyu Wang <zhenyuw@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200528033559.GG23961@zhen-hp.sh.intel.com
2020-06-02 16:45:06 +03:00
Jiri Olsa
a9a1790247 perf stat: Ensure group is defined on top of the same cpu mask
Jin Yao reported the issue (and posted first versions of this change)
with groups being defined over events with different cpu mask.

This causes assert aborts in get_group_fd, like:

  # perf stat -M "C2_Pkg_Residency" -a -- sleep 1
  perf: util/evsel.c:1464: get_group_fd: Assertion `!(fd == -1)' failed.
  Aborted

All the events in the group have to be defined over the same cpus so the
group_fd can be found for every leader/member pair.

Adding check to ensure this condition is met and removing the group
(with warning) if we detect mixed cpus, like:

  $ sudo perf stat -e '{power/energy-cores/,cycles},{instructions,power/energy-cores/}'
  WARNING: event cpu maps do not match, disabling group:
    anon group { power/energy-cores/, cycles }
    anon group { instructions, power/energy-cores/ }

Ian asked also for cpu maps details, it's displayed in verbose mode:

  $ sudo perf stat -e '{cycles,power/energy-cores/}' -v
  WARNING: group events cpu maps do not match, disabling group:
    anon group { power/energy-cores/, cycles }
       power/energy-cores/: 0
       cycles: 0-7
    anon group { instructions, power/energy-cores/ }
       instructions: 0-7
       power/energy-cores/: 0

Committer testing:

  [root@seventh ~]# perf stat -e '{power/energy-cores/,cycles},{instructions,power/energy-cores/}'
  WARNING: grouped events cpus do not match, disabling group:
    anon group { power/energy-cores/, cycles }
    anon group { instructions, power/energy-cores/ }
  ^C
   Performance counter stats for 'system wide':

               12.62 Joules power/energy-cores/
         106,920,637        cycles
          80,228,899        instructions              #    0.75  insn per cycle
               12.62 Joules power/energy-cores/

        14.514476987 seconds time elapsed

  [root@seventh ~]#

But if we put compatible events in each group it works:

  [root@seventh ~]# perf stat -e '{power/energy-cores/,power/energy-ram/},{instructions,cycles}' -a sleep 2

   Performance counter stats for 'system wide':

                1.95 Joules power/energy-cores/
                0.92 Joules power/energy-ram/
          29,305,715        instructions              #    1.03  insn per cycle
          28,423,338        cycles

         2.001438142 seconds time elapsed

  [root@seventh ~]#

This needs improvement tho:

  [root@seventh ~]# perf stat -e '{power/energy-cores/,power/energy-ram/},{instructions,cycles}' sleep 2
  Error:
  The sys_perf_event_open() syscall returned with 22 (Invalid argument) for event (power/energy-cores/).
  /bin/dmesg | grep -i perf may provide additional information.

  [root@seventh ~]#

We need to emit a better message, one stating that the power/ events
can't be used for a specific workload, instead it is per-cpu or system
wide.

Fixes: 6a4bb04caa ("perf tools: Enable grouping logic for parsed events")
Co-developed-by: Jin Yao <yao.jin@linux.intel.com>
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Acked-by: Ian Rogers <irogers@google.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Michael Petlan <mpetlan@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lore.kernel.org/lkml/20200602101736.GE1112120@krava
Signed-off-by: Jin Yao <yao.jin@linux.intel.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2020-06-02 10:43:06 -03:00
Jani Nikula
62b6e899a0 drm/i915/params: fix i915.fake_lmem_start module param sysfs permissions
fake_lmem_start does not need to be mutable via module param sysfs. It's
only used during driver probe.

Fixes: 1629224324 ("drm/i915/lmem: add the fake lmem region")
Cc: Matthew Auld <matthew.auld@intel.com>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200601215510.18379-2-jani.nikula@intel.com
(cherry picked from commit f322e851f2)
Signed-off-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
2020-06-02 16:35:37 +03:00
Jani Nikula
ea2b383ded drm/i915/params: don't expose inject_probe_failure in debugfs
The parameter only makes sense as a module parameter only.

Fixes: c43c5a8818 ("drm/i915/params: add i915 parameters to debugfs")
Cc: Juha-Pekka Heikkilä <juha-pekka.heikkila@intel.com>
Cc: Venkata Sandeep Dhanalakota <venkata.s.dhanalakota@intel.com>
Reviewed-by: Juha-Pekka Heikkila <juhapekka.heikkila@gmail.com>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200601215510.18379-1-jani.nikula@intel.com
(cherry picked from commit dbf4081ffb)
Signed-off-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
2020-06-02 16:35:33 +03:00
Chris Wilson
273500ae71 drm/i915: Whitelist context-local timestamp in the gen9 cmdparser
Allow batch buffers to read their own _local_ cumulative HW runtime of
their logical context.

Fixes: 0f2f397583 ("drm/i915: Add gen9 BCS cmdparsing")
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Cc: <stable@vger.kernel.org> # v5.4+
Reviewed-by: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200601161942.30854-1-chris@chris-wilson.co.uk
(cherry picked from commit f9496520df)
Signed-off-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
2020-06-02 16:35:29 +03:00
Ville Syrjälä
882f38b7f6 drm/i915: Fix global state use-after-frees with a refcount
While the current locking/serialization of the global state
suffices for protecting the obj->state access and the actual
hardware reprogramming, we do have a problem with accessing
the old/new states during nonblocking commits.

The state computation and swap will be protected by the crtc
locks, but the commit_tails can finish out of order, thus also
causing the atomic states to be cleaned up out of order. This
would mean the commit that started first but finished last has
had its new state freed as the no-longer-needed old state by the
other commit.

To fix this let's just refcount the states. obj->state amounts
to one reference, and the intel_atomic_state holds extra references
to both its new and old global obj states.

Fixes: 0ef1905ecf ("drm/i915: Introduce better global state handling")
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200527200245.13184-1-ville.syrjala@linux.intel.com
Reviewed-by: Stanislav Lisovskiy <stanislav.lisovskiy@intel.com>
(cherry picked from commit f8c86ffa28)
Signed-off-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
2020-06-02 16:35:24 +03:00
Sandipan Patra
1d7796bdb6 pwm: tegra: Support dynamic clock frequency configuration
Added support for dynamic clock freq configuration in PWM kernel driver.
Earlier the PWM driver used to cache boot time clock rate by PWM clock
parent during probe. Hence dynamically changing PWM frequency was not
possible for all the possible ranges. With this change, dynamic
calculation is enabled and it is able to set the requested period from
sysfs knob provided the value is supported by clock source.

Changes mainly have 2 parts:
  - Tegra186 and later chips [1]
  - Tegra210 and prior chips [2]

For [1] - Changes implemented to set pwm period dynamically and also
          checks added to allow only if requested period(ns) is below or
          equals to higher range.

For [2] - Only checks if the requested period(ns) is below or equals to
          higher range defined by max clock limit. The limitation in
          Tegra210 or prior chips are due to the reason of having only
          one PWM controller supporting multiple channels. But later
          chips have multiple PWM controller instances each having
          single channel support.

Signed-off-by: Sandipan Patra <spatra@nvidia.com>
Reviewed-by: Jon Hunter <jonathanh@nvidia.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2020-06-02 14:25:37 +02:00
Paul Cercueil
74db728c0b pwm: jz4740: Add support for the JZ4725B
The PWM hardware in the JZ4725B works the same as in the JZ4740, but has
only six channels available.

Signed-off-by: Paul Cercueil <paul@crapouillou.net>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2020-06-02 14:24:57 +02:00
Paul Cercueil
a020f22a4f pwm: jz4740: Make PWM start with the active part
The PWM in Ingenic SoCs starts in inactive state until the internal
timer reaches the duty value, then becomes active until the timer
reaches the period value. In theory, we should then use (period - duty)
as the real duty value, as a high duty value would otherwise result in
the PWM pin being inactive most of the time.

This is the reason why the duty value was inverted in the driver until
now, but it still had the problem that it would not start with the
active part.

To address this remaining issue, the common trick is to invert the
duty, and invert the polarity when the PWM is enabled.

Since the duty was already inverted, and we invert it again, we now
program the hardware for the requested duty, and simply invert the
polarity when the PWM is enabled.

Signed-off-by: Paul Cercueil <paul@crapouillou.net>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2020-06-02 14:24:26 +02:00
Paul Cercueil
9017dc4fbd pwm: jz4740: Enhance precision in calculation of duty cycle
Calculating the hardware value for the duty from the hardware value of
the period resulted in a precision loss versus calculating it from the
clock rate directly.

(Also remove a cast that doesn't really need to be here)

Fixes: f6b8a57000 ("pwm: Add Ingenic JZ4740 support")
Cc: <stable@vger.kernel.org>
Suggested-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Reviewed-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Paul Cercueil <paul@crapouillou.net>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2020-06-02 14:24:00 +02:00
Paul Cercueil
b48d49e0d5 pwm: jz4740: Drop dependency on MACH_INGENIC
Depending on MACH_INGENIC prevent us from creating a generic kernel that
works on more than one MIPS board. Instead, we just depend on MIPS being
set.

Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Paul Cercueil <paul@crapouillou.net>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2020-06-02 14:23:42 +02:00
Hans de Goede
01aa905d47 pwm: lpss: Fix get_state runtime-pm reference handling
Before commit cfc4c189bc ("pwm: Read initial hardware state at request
time"), a driver's get_state callback would get called once per PWM from
pwmchip_add().

pwm-lpss' runtime-pm code was relying on this, getting a runtime-pm ref for
PWMs which are enabled at probe time from within its get_state callback,
before enabling runtime-pm.

The change to calling get_state at request time causes a number of
problems:

1. PWMs enabled at probe time may get runtime suspended before they are
requested, causing e.g. a LCD backlight controlled by the PWM to turn off.

2. When the request happens when the PWM has been runtime suspended, the
ctrl register will read all 1 / 0xffffffff, causing get_state to store
bogus values in the pwm_state.

3. get_state was using an async pm_runtime_get() call, because it assumed
that runtime-pm has not been enabled yet. If shortly after the request an
apply call is made, then the pwm_lpss_is_updating() check may trigger
because the resume triggered by the pm_runtime_get() call is not complete
yet, so the ctrl register still reads all 1 / 0xffffffff.

This commit fixes these issues by moving the initial pm_runtime_get() call
for PWMs which are enabled at probe time to the pwm_lpss_probe() function;
and by making get_state take a runtime-pm ref before reading the ctrl reg.

BugLink: https://bugzilla.redhat.com/show_bug.cgi?id=1828927
Fixes: cfc4c189bc ("pwm: Read initial hardware state at request time")
Cc: stable@vger.kernel.org
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2020-06-02 14:21:42 +02:00
Oliver O'Halloran
4336b93378 powerpc/pseries: Make vio and ibmebus initcalls pseries specific
The vio and ibmebus buses are used for pseries specific
paravirtualised devices and currently they're initialised by the
generic initcall types. This is mostly fine, but it can result in some
nuisance errors in dmesg when booting on PowerNV on some OSes, e.g.

  [    2.984439] synth uevent: /devices/vio: failed to send uevent
  [    2.984442] vio vio: uevent: failed to send synthetic uevent
  [   17.968551] synth uevent: /devices/vio: failed to send uevent
  [   17.968554] vio vio: uevent: failed to send synthetic uevent

We don't see anything similar for the ibmebus because that depends on
!CONFIG_LITTLE_ENDIAN.

This patch squashes those by switching to using machine_*_initcall()
so the bus type is only registered when the kernel is running on a
pseries machine.

Signed-off-by: Oliver O'Halloran <oohall@gmail.com>
Reviewed-by: Tyrel Datwyler <tyreld@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200421081539.7485-1-oohall@gmail.com
2020-06-02 22:21:31 +10:00
Peter Vasil
856c45d8c1 pwm: sun4i: Support direct clock output on Allwinner A64
Allwinner A64 is capable of a direct clock output on PWM (see A64 User
Manual chapter 3.10). Add support for this in the sun4i PWM driver.

Signed-off-by: Peter Vasil <peter.vasil@gmail.com>
Acked-by: Maxime Ripard <mripard@kernel.org>
Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2020-06-02 14:20:11 +02:00
Eric Farman
4296151d23 vfio-ccw: Refactor IRQ handlers
To simplify future expansion.

Signed-off-by: Eric Farman <farman@linux.ibm.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Message-Id: <20200505122745.53208-6-farman@linux.ibm.com>
Signed-off-by: Cornelia Huck <cohuck@redhat.com>
2020-06-02 13:14:08 +02:00
Farhan Ali
24c986748b vfio-ccw: Introduce a new schib region
The schib region can be used by userspace to get the subchannel-
information block (SCHIB) for the passthrough subchannel.
This can be useful to get information such as channel path
information via the SCHIB.PMCW fields.

Signed-off-by: Farhan Ali <alifm@linux.ibm.com>
Signed-off-by: Eric Farman <farman@linux.ibm.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Message-Id: <20200505122745.53208-5-farman@linux.ibm.com>
Signed-off-by: Cornelia Huck <cohuck@redhat.com>
2020-06-02 13:14:08 +02:00
Eric Farman
600279b526 vfio-ccw: Refactor the unregister of the async regions
This is mostly for the purposes of a later patch, since
we'll need to do the same thing later.

While we are at it, move the resulting function call to ahead
of the unregistering of the IOMMU notifier, so that it's done
in the reverse order of how it was created.

Signed-off-by: Eric Farman <farman@linux.ibm.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Message-Id: <20200505122745.53208-4-farman@linux.ibm.com>
Signed-off-by: Cornelia Huck <cohuck@redhat.com>
2020-06-02 13:14:08 +02:00
Farhan Ali
b7701dfbf9 vfio-ccw: Register a chp_event callback for vfio-ccw
Register the chp_event callback to receive channel path related
events for the subchannels managed by vfio-ccw.

Signed-off-by: Farhan Ali <alifm@linux.ibm.com>
Signed-off-by: Eric Farman <farman@linux.ibm.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Message-Id: <20200505122745.53208-3-farman@linux.ibm.com>
Signed-off-by: Cornelia Huck <cohuck@redhat.com>
2020-06-02 13:14:08 +02:00
Farhan Ali
9a44ce6c9b vfio-ccw: Introduce new helper functions to free/destroy regions
Consolidate some of the cleanup code for the regions, so that
as more are added we reduce code duplication.

Signed-off-by: Farhan Ali <alifm@linux.ibm.com>
Signed-off-by: Eric Farman <farman@linux.ibm.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Message-Id: <20200505122745.53208-2-farman@linux.ibm.com>
Signed-off-by: Cornelia Huck <cohuck@redhat.com>
2020-06-02 13:14:08 +02:00
Cornelia Huck
430220b0bb vfio-ccw: document possible errors
Interacting with the I/O and the async regions can yield a number
of errors, which had been undocumented so far. These are part of
the api, so remedy that.

Signed-off-by: Cornelia Huck <cohuck@redhat.com>
Reviewed-by: Eric Farman <farman@linux.ibm.com>
Message-Id: <20200407111605.1795-1-cohuck@redhat.com>
2020-06-02 13:14:08 +02:00
Jared Rossi
725b94d741 vfio-ccw: Enable transparent CCW IPL from DASD
Remove the explicit prefetch check when using vfio-ccw devices.
This check does not trigger in practice as all Linux channel programs
are intended to use prefetch.

It is expected that all ORBs issued by Linux will request prefetch.
Although non-prefetching ORBs are not rejected, they will prefetch
nonetheless. A warning is issued up to once per 5 seconds when a
forced prefetch occurs.

A non-prefetch ORB does not necessarily result in an error, however
frequent encounters with non-prefetch ORBs indicate that channel
programs are being executed in a way that is inconsistent with what
the guest is requesting. While there is currently no known case of an
error caused by forced prefetch, it is possible in theory that forced
prefetch could result in an error if applied to a channel program that
is dependent on non-prefetch.

Signed-off-by: Jared Rossi <jrossi@linux.ibm.com>
Reviewed-by: Eric Farman <farman@linux.ibm.com>
Message-Id: <20200506212440.31323-2-jrossi@linux.ibm.com>
Signed-off-by: Cornelia Huck <cohuck@redhat.com>
2020-06-02 13:14:08 +02:00
Andrew Donnellan
f44b85da5e cxl: Remove dead Kconfig options
The CXL_AFU_DRIVER_OPS and CXL_LIB Kconfig options were added to coordinate
merging of new features. They no longer serve any purpose, so remove them.

Signed-off-by: Andrew Donnellan <ajd@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200602040341.10152-1-ajd@linux.ibm.com
2020-06-02 20:59:21 +10:00
Alistair Popple
a3ea40d5c7 powerpc: Add POWER10 architected mode
PVR value of 0x0F000006 means we are arch v3.1 compliant (i.e.
POWER10). This is used by phyp and kvm when booting as a pseries guest
to detect the presence of new P10 features and to enable the
appropriate hwcap and facility bits.

Signed-off-by: Alistair Popple <alistair@popple.id.au>
Signed-off-by: Cédric Le Goater <clg@kaod.org>
[mpe: Fall through to __init_FSCR rather than duplicating it, drop
      hack to set current->thread.fscr now that is handled elsewhere.]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200521014341.29095-8-alistair@popple.id.au
2020-06-02 20:59:20 +10:00
Alistair Popple
87939d50e5 powerpc/dt_cpu_ftrs: Add MMA feature
Matrix multiple assist (MMA) is a new feature added to ISAv3.1 and
POWER10. Support on powernv can be selected via a firmware CPU device
tree feature which enables it via a PCR bit.

Signed-off-by: Alistair Popple <alistair@popple.id.au>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200521014341.29095-7-alistair@popple.id.au
2020-06-02 20:59:20 +10:00
Alistair Popple
c63d688c3d powerpc/dt_cpu_ftrs: Enable Prefixed Instructions
Prefix instructions have their own FSCR bit which needs to be enabled
via a CPU feature. The kernel will save the FSCR for problem state but
it needs to be enabled initially.

Signed-off-by: Alistair Popple <alistair@popple.id.au>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200521014341.29095-6-alistair@popple.id.au
2020-06-02 20:59:20 +10:00