967030 Commits

Author SHA1 Message Date
Harald Freudenberger
ff98cc986a s390/crypto: add arch_get_random_long() support
The random longs to be pulled by arch_get_random_long() are
prepared in an 4K buffer which is filled from the NIST 800-90
compliant s390 drbg. By default the random long buffer is refilled
256 times before the drbg itself needs a reseed. The reseed of the
drbg is done with 32 bytes fetched from the high quality (but slow)
trng which is assumed to deliver 100% entropy. So the 32 * 8 = 256
bits of entropy are spread over 256 * 4KB = 1MB serving 131072
arch_get_random_long() invocations before reseeded.

How often the 4K random long buffer is refilled with the drbg
before the drbg is reseeded can be adjusted. There is a module
parameter 's390_arch_rnd_long_drbg_reseed' accessible via
  /sys/module/arch_random/parameters/rndlong_drbg_reseed
or as kernel command line parameter
  arch_random.rndlong_drbg_reseed=<value>
This parameter tells how often the drbg fills the 4K buffer before
it is re-seeded by fresh entropy from the trng.
A value of 16 results in reseeding the drbg at every 16 * 4 KB = 64
KB with 32 bytes of fresh entropy pulled from the trng. So a value
of 16 would result in 256 bits entropy per 64 KB.
A value of 256 results in 1MB of drbg output before a reseed of the
drbg is done. So this would spread the 256 bits of entropy among 1MB.
Setting this parameter to 0 forces the reseed to take place every
time the 4K buffer is depleted, so the entropy rises to 256 bits
entropy per 4K or 0.5 bit entropy per arch_get_random_long().  With
setting this parameter to negative values all this effort is
disabled, arch_get_random long() returns false and thus indicating
that the arch_get_random_long() feature is disabled at all.

arch_get_random_long() is used by random.c among others to provide
an initial hash value to be mixed with the entropy pool on every
random data pull. For about 64 bytes read from /dev/urandom there
is one call to arch_get_random_long(). So these additional random
long values count for performance of /dev/urandom with measurable
but low penalty.

Signed-off-by: Harald Freudenberger <freude@linux.ibm.com>
Reviewed-by: Ingo Franzki <ifranzki@linux.ibm.com>
Reviewed-by: Juergen Christ <jchrist@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2020-12-10 21:02:08 +01:00
Sven Schnelle
b5e438ebd7 s390/smp: perform initial CPU reset also for SMT siblings
Not resetting the SMT siblings might leave them in unpredictable
state. One of the observed problems was that the CPU timer wasn't
reset and therefore large system time values where accounted during
CPU bringup.

Cc: <stable@kernel.org> # 4.0
Fixes: 10ad34bc76dfb ("s390: add SMT support")
Reviewed-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Sven Schnelle <svens@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2020-12-09 21:02:08 +01:00
Heiko Carstens
b4d70a6134 s390/mm: use invalid asce for user space when switching to init_mm
Currently only idle_task_exit() explicitly switches (switch_mm) to
init_mm. This causes the kernel asce to be loaded into cr7 and
therefore it would be used for potential user space accesses.

This is currently no problem since idle_task_exit() is nearly the last
thing a CPU executes before it is taken down. However things might
change - and therefore make sure that always the invalid asce is used
for cr7 when active_mm is init_mm.

This makes sure that all potential user space accesses will fail,
instead of accessing kernel address space.

Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2020-12-09 21:02:08 +01:00
Sven Schnelle
454efcf82e s390/idle: fix accounting with machine checks
When a machine check interrupt is triggered during idle, the code
is using the async timer/clock for idle time calculation. It should use
the machine check enter timer/clock which is passed to the macro.

Fixes: 0b0ed657fe00 ("s390: remove critical section cleanup from entry.S")
Cc: <stable@vger.kernel.org> # 5.8
Reviewed-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Sven Schnelle <svens@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2020-12-09 21:02:07 +01:00
Sven Schnelle
e259b3fafa s390/idle: add missing mt_cycles calculation
During removal of the critical section cleanup the calculation
of mt_cycles during idle was removed. This causes invalid
accounting on systems with SMT enabled.

Fixes: 0b0ed657fe00 ("s390: remove critical section cleanup from entry.S")
Cc: <stable@vger.kernel.org> # 5.8
Reviewed-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Sven Schnelle <svens@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2020-12-09 21:02:07 +01:00
Philipp Rudo
7a84ffc047 s390/boot: add build-id to decompressor
More and more functionality from the early boot phase gets carried over
to the decompressor. With this the complexity of the code and thus the
chance to introduce bugs increases. In order to be able to debug these
early boot bugs the distributions have to package the decompressors
vmlinux together with the other debuginfos. However for that the
distributions require the vmlinux to contain a build-id.

Per default the section containing the build-id is placed first in the
section table. So make sure to move it behind the .text section
otherwise the image would be unbootable.

Signed-off-by: Philipp Rudo <prudo@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2020-12-09 21:02:07 +01:00
Philipp Rudo
613775d62e s390/kexec_file: fix diag308 subcode when loading crash kernel
diag308 subcode 0 performes a clear reset which inlcudes the reset of
all registers in the system. While this is the preferred behavior when
loading a normal kernel via kexec it prevents the crash kernel to store
the register values in the dump. To prevent this use subcode 1 when
loading a crash kernel instead.

Fixes: ee337f5469fd ("s390/kexec_file: Add crash support to image loader")
Cc: <stable@vger.kernel.org> # 4.17
Signed-off-by: Philipp Rudo <prudo@linux.ibm.com>
Reported-by: Xiaoying Yan <yiyan@redhat.com>
Tested-by: Lianbo Jiang <lijiang@redhat.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2020-12-09 21:02:07 +01:00
Qinglang Miao
14d4c4fa46 s390/cio: fix use-after-free in ccw_device_destroy_console
Use of sch->dev reference after the put_device() call could trigger
the use-after-free bugs.

Fix this by simply adjusting the position of put_device.

Fixes: 37db8985b211 ("s390/cio: add basic protected virtualization support")
Reported-by: Hulk Robot <hulkci@huawei.com>
Suggested-by: Cornelia Huck <cohuck@redhat.com>
Signed-off-by: Qinglang Miao <miaoqinglang@huawei.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Reviewed-by: Vineeth Vijayan <vneethv@linux.ibm.com>
[vneethv@linux.ibm.com: Slight modification in the commit-message]
Signed-off-by: Vineeth Vijayan <vneethv@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2020-12-09 21:02:07 +01:00
Vineeth Vijayan
8cc0dcfdc1 s390/cio: remove pm support from ccw bus driver
As part of removing broken pm-support from s390 arch, remove
the pm callbacks from ccw-bus driver.The power-management functions
are unused since the 'commit 394216275c7d ("s390: remove broken
hibernate / power management support")'.

Signed-off-by: Vineeth Vijayan <vneethv@linux.ibm.com>
Reviewed-by: Peter Oberparleiter <oberpar@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2020-12-02 18:19:25 +01:00
Vineeth Vijayan
ef2eea78a6 s390/cio: remove pm support from css-bus driver
The power-management functions are unused since the
'commit 394216275c7d ("s390: remove broken hibernate / power
management support")'. Remove the unused pm callbacks from
css-bus driver.

Signed-off-by: Vineeth Vijayan <vneethv@linux.ibm.com>
Reviewed-by: Peter Oberparleiter <oberpar@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2020-12-02 18:19:25 +01:00
Vineeth Vijayan
796cfabde5 s390/cio: remove pm support from IO subchannel drivers
The power-management functions are unused since the
'commit 394216275c7d ("s390: remove broken hibernate / power
management support")'. Remove these unused pm callbacks from
io-subchannel drivers.

Signed-off-by: Vineeth Vijayan <vneethv@linux.ibm.com>
Reviewed-by: Peter Oberparleiter <oberpar@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2020-12-02 18:19:25 +01:00
Vineeth Vijayan
bfa11151d2 s390/cio: remove pm support from chsc subchannel driver
As part of removing the broken pm-support from s390 arch, remove
the pm-calls from chsc subchannel driver. The power-management
functions are unused since the 'commit 394216275c7d ("s390: remove
broken hibernate / power management support")'.

Signed-off-by: Vineeth Vijayan <vneethv@linux.ibm.com>
Reviewed-by: Peter Oberparleiter <oberpar@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2020-12-02 18:19:25 +01:00
Vineeth Vijayan
74cee7f3b0 s390/vmur: remove unused pm related functions
The Power-management related functions are unused since
'commit 394216275c7d ("s390: remove broken hibernate / power management
support")'. Remove them from the unit-record device driver.

Signed-off-by: Vineeth Vijayan <vneethv@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2020-12-02 18:19:24 +01:00
Vineeth Vijayan
2f6ea6fb88 s390/tape: remove unsupported PM functions
The power-management related functions are unused since
'commit 394216275c7d ("s390: remove broken hibernate / power
management support")'. Remove them from tape drivers.

Signed-off-by: Vineeth Vijayan <vneethv@linux.ibm.com>
Reviewed-by: Jan Höppner <hoeppner@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2020-12-02 18:19:24 +01:00
Vineeth Vijayan
6b532eec75 s390/cio: remove pm support from eadm-sch drivers
The 'commit 394216275c7d ("s390: remove broken hibernate /
power management support")' removes the pm-support. Remove the
unused functions in eadm-sch drivers.

Signed-off-by: Vineeth Vijayan <vneethv@linux.ibm.com>
Reviewed-by: Peter Oberparleiter <oberpar@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2020-12-02 18:19:24 +01:00
Vineeth Vijayan
1cf69b7b51 s390: remove pm support from console drivers
The power-management functions are unused since the
'commit 394216275c7d ("s390: remove broken hibernate / power management
support")'. Remove the unsued pm functions from the console drivers.

Signed-off-by: Vineeth Vijayan <vneethv@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2020-12-02 18:19:24 +01:00
Vineeth Vijayan
127fca6093 s390/dasd: remove unused pm related functions
The power-management related functions are unused since the
'commit 394216275c7d ("s390: remove broken hibernate / power management
support")'. Remove them from dasd drivers.

Signed-off-by: Vineeth Vijayan <vneethv@linux.ibm.com>
Reviewed-by: Stefan Haberland <sth@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2020-12-02 18:19:23 +01:00
Vineeth Vijayan
5db44cfe2e s390/zfcp: remove pm support from zfcp driver
As part of removing the power management support from
s390 arch, remove PM callbacks from the scsi/zfcp driver.

Signed-off-by: Vineeth Vijayan <vneethv@linux.ibm.com>
Reviewed-by: Steffen Maier <maier@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2020-12-02 18:19:23 +01:00
Julian Wiedmann
8cb4c20f32 s390/ap: let bus_register() add the AP bus sysfs attributes
Instead of creating the sysfs attributes for the AP bus by hand,
describe them in .bus_groups and let the driver core handle it.

Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com>
Signed-off-my: Harald Freudenberger <freude@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2020-11-30 14:10:50 +01:00
Heiko Carstens
1ab3001b6e s390/vdso: add missing prototypes for vdso functions
clang W=1 warns about missing prototypes:

>> arch/s390/kernel/vdso64/getcpu.c:8:5: warning: no previous prototype for function '__s390_vdso_getcpu' [-Wmissing-prototypes]
   int __s390_vdso_getcpu(unsigned *cpu, unsigned *node, struct getcpu_cache *unused)
       ^

Add a local header file in order to get rid of this warnings.

Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2020-11-30 14:10:50 +01:00
Niklas Schnelle
10e5921747 s390/Kconfig: default PCI_NR_FUNCTIONS to 512
With the addition of more complete SR-IOV support, we are recommending
to raise this limit for distributions to 512, as the previous default of
128 can easily be hit with just the VFs of a single PCI physical
function.
With at least one distribution now shipping with this, supporting
only one fourth as many PCI functions on a default upstream build may
lead to confusion and reduced testing of the higher limit so increase
the default to 512.

Acked-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Niklas Schnelle <schnelle@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2020-11-30 14:10:49 +01:00
Heiko Carstens
80f0630624 s390/vdso: reimplement getcpu vdso syscall
Implement the previously removed getcpu vdso syscall by using the
TOD programmable field to pass the cpu number to user space.

Reviewed-by: Sven Schnelle <svens@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2020-11-23 12:01:13 +01:00
Heiko Carstens
062e527956 s390/mm: add debug user asce support
Verify on exit to user space that always
- the primary ASCE (cr1) is set to kernel ASCE
- the secondary ASCE (cr7) is set to user ASCE

If this is not the case: panic since something went terribly wrong.

Reviewed-by: Sven Schnelle <svens@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2020-11-23 12:01:12 +01:00
Heiko Carstens
0290c9e328 s390/mm: use invalid asce instead of kernel asce
Create a region 3 page table which contains only invalid entries, and
use that via "s390_invalid_asce" instead of the kernel ASCE whenever
there is either
- no user address space available, e.g. during early startup
- as an intermediate ASCE when address spaces are switched

This makes sure that user space accesses in such situations are
guaranteed to fail.

Reviewed-by: Sven Schnelle <svens@linux.ibm.com>
Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2020-11-23 12:01:12 +01:00
Heiko Carstens
87d5986345 s390/mm: remove set_fs / rework address space handling
Remove set_fs support from s390. With doing this rework address space
handling and simplify it. As a result address spaces are now setup
like this:

CPU running in              | %cr1 ASCE | %cr7 ASCE | %cr13 ASCE
----------------------------|-----------|-----------|-----------
user space                  |  user     |  user     |  kernel
kernel, normal execution    |  kernel   |  user     |  kernel
kernel, kvm guest execution |  gmap     |  user     |  kernel

To achieve this the getcpu vdso syscall is removed in order to avoid
secondary address mode and a separate vdso address space in for user
space. The getcpu vdso syscall will be implemented differently with a
subsequent patch.

The kernel accesses user space always via secondary address space.
This happens in different ways:
- with mvcos in home space mode and directly read/write to secondary
  address space
- with mvcs/mvcp in primary space mode and copy from primary space to
  secondary space or vice versa
- with e.g. cs in secondary space mode and access secondary space

Switching translation modes happens with sacf before and after
instructions which access user space, like before.

Lazy handling of control register reloading is removed in the hope to
make everything simpler, but at the cost of making kernel entry and
exit a bit slower. That is: on kernel entry the primary asce is always
changed to contain the kernel asce, and on kernel exit the primary
asce is changed again so it contains the user asce.

In kernel mode there is only one exception to the primary asce: when
kvm guests are executed the primary asce contains the gmap asce (which
describes the guest address space). The primary asce is reset to
kernel asce whenever kvm guest execution is interrupted, so that this
doesn't has to be taken into account for any user space accesses.

Reviewed-by: Sven Schnelle <svens@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2020-11-23 12:01:12 +01:00
Heiko Carstens
77663819d4 Merge branch 'fixes' into features
* fixes:
  s390: fix fpu restore in entry.S

Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2020-11-23 12:00:42 +01:00
Sven Schnelle
1179f170b6 s390: fix fpu restore in entry.S
We need to disable interrupts in load_fpu_regs(). Otherwise an
interrupt might come in after the registers are loaded, but before
CIF_FPU is cleared in load_fpu_regs(). When the interrupt returns,
CIF_FPU will be cleared and the registers will never be restored.

The entry.S code usually saves the interrupt state in __SF_EMPTY on the
stack when disabling/restoring interrupts. sie64a however saves the pointer
to the sie control block in __SF_SIE_CONTROL, which references the same
location.  This is non-obvious to the reader. To avoid thrashing the sie
control block pointer in load_fpu_regs(), move the __SIE_* offsets eight
bytes after __SF_EMPTY on the stack.

Cc: <stable@vger.kernel.org> # 5.8
Fixes: 0b0ed657fe00 ("s390: remove critical section cleanup from entry.S")
Reported-by: Pierre Morel <pmorel@linux.ibm.com>
Signed-off-by: Sven Schnelle <svens@linux.ibm.com>
Acked-by: Christian Borntraeger <borntraeger@de.ibm.com>
Reviewed-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2020-11-23 11:52:13 +01:00
Heiko Carstens
334ef6ed06 init/Kconfig: make COMPILE_TEST depend on !S390
While allmodconfig and allyesconfig build for s390 there are also
various bots running compile tests with randconfig, where PCI is
disabled. This reveals that a lot of drivers should actually depend on
HAS_IOMEM.
Adding this to each device driver would be a never ending story,
therefore just disable COMPILE_TEST for s390.

The reasoning is more or less the same as described in
commit bc083a64b6c0 ("init/Kconfig: make COMPILE_TEST depend on !UML").

Reported-by: kernel test robot <lkp@intel.com>
Suggested-by: Arnd Bergmann <arnd@kernel.org>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2020-11-20 19:19:12 +01:00
Alexander Gordeev
12bb4c6823 s390/vmem: make variable and function names consistent
Rename some variable and functions to better clarify
what they are and what they do.

Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2020-11-20 19:19:12 +01:00
Alexander Gordeev
af71657c15 s390/vmem: remove redundant check
Reviewed-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2020-11-20 19:19:12 +01:00
Julian Wiedmann
074ff04e27 s390/stp: let subsys_system_register() sysfs attributes
Instead of creating the sysfs attributes for the stp root_dev by hand,
pass them to subsys_system_register() as parameter.

This also ensures that the attributes are available when the KOBJ_ADD
event is raised.

Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2020-11-20 19:19:11 +01:00
Vasily Gorbik
ba1a6be994 s390/decompressor: print cmdline and BEAR on pgm_check
Add kernel command line and last breaking event.
The kernel command line is taken from early_command_line and printed
only if kernel is not running as protected virtualization guest and
if it has been already initialized from the "COMMAND_LINE".

Linux version 5.10.0-rc3-22794-gecaa72788df0-dirty (gor@tuxmaker) #28 SMP PREEMPT Mon Nov 9 17:41:20 CET 2020
Kernel command line: audit_enable=0 audit=0 selinux=0 crashkernel=296M root=/dev/dasda1 dasd=ec5b
memblock=debug die
Kernel fault: interruption code 0005 ilc:2
PSW : 0000000180000000 0000000000012f92 (parse_boot_command_line+0x27a/0x46c)
      R:0 T:0 IO:0 EX:0 Key:0 M:0 W:0 P:0 AS:0 CC:0 PM:0 RI:0 EA:3
GPRS: 0000000000000000 00ffffffffffffff 0000000000000000 000000000001a65c
      000000000000bf60 0000000000000000 00000000000003c0 0000000000000000
      0000000000000080 000000000002322d 000000007f29ef20 0000000000efd018
      000000000311c000 0000000000010070 0000000000012f82 000000000000bea8
Call Trace:
(sp:000000000000bea8 [<000000000002016e>] 000000000002016e)
 sp:000000000000bf18 [<0000000000012408>] startup_kernel+0x88/0x2fc
 sp:000000000000bf60 [<00000000000100c4>] startup_normal+0xb0/0xb0
Last Breaking-Event-Address:
 [<00000000000135ba>] strcmp+0x22/0x24

Reviewed-by: Alexander Egorenkov <egorenar@linux.ibm.com>
Acked-by: Viktor Mihajlovski <mihajlov@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2020-11-20 19:19:11 +01:00
Vasily Gorbik
8977ab65b8 s390/decompressor: add stacktrace support
Decompressor works on a single statically allocated stack. Stacktrace
implementation with -mbackchain just takes few lines of code.

Linux version 5.10.0-rc3-22793-g0f84a355b776-dirty (gor@tuxmaker) #27 SMP PREEMPT Mon Nov 9 17:30:18 CET 2020
Kernel fault: interruption code 0005 ilc:2
PSW : 0000000180000000 0000000000012f92 (parse_boot_command_line+0x27a/0x46c)
      R:0 T:0 IO:0 EX:0 Key:0 M:0 W:0 P:0 AS:0 CC:0 PM:0 RI:0 EA:3
GPRS: 0000000000000000 00ffffffffffffff 0000000000000000 000000000001a62c
      000000000000bf60 0000000000000000 00000000000003c0 0000000000000000
      0000000000000080 000000000002322d 000000007f29ef20 0000000000efd018
      000000000311c000 0000000000010070 0000000000012f82 000000000000bea8
Call Trace:
(sp:000000000000bea8 [<000000000002016e>] 000000000002016e)
 sp:000000000000bf18 [<0000000000012408>] startup_kernel+0x88/0x2fc
 sp:000000000000bf60 [<00000000000100c4>] startup_normal+0xb0/0xb0

Reviewed-by: Alexander Egorenkov <egorenar@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2020-11-20 19:19:11 +01:00
Vasily Gorbik
246218962e s390/decompressor: add symbols support
Information printed by print_pgm_check_info() is crucial for
debugging decompressor problems. Printing instruction addresses is
better than nothing, but turns further debugging into tedious job of
figuring out which function those addresses correspond to.

This change adds simplistic symbols resolution support. And adds %pS
format specifier support to decompressor_printk().

Decompressor symbols list is extracted and sorted with
nm -n -S:
...
0000000000010000 0000000000000014 T startup
0000000000010014 00000000000000b0 t startup_normal
0000000000010180 00000000000000b2 t startup_kdump
...

Then functions are filtered and contracted to a form:
"10000 14 startup\0""10014 b0 startup_normal\0""10180 b2 startup_kdump\0"
...
Which makes it trivial to find beginning of an entry and names are 0
terminated, so could be used as is. Symbols are binary-searched.

To get symbols list with final addresses and then get it into the
decompressor's image the same trick as for kallsyms is used.
Decompressor's vmlinux is linked twice.

Symbols are stored in .decompressor.syms section, current size is about
2kb.

Reviewed-by: Alexander Egorenkov <egorenar@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2020-11-20 19:19:11 +01:00
Vasily Gorbik
ec55d1e1db s390/decompressor: correct some asm symbols annotations
Use SYM_CODE_* annotations for asm functions, so that function lengths
are recognized correctly.

Also currently the most part of startup is marked as startup_kdump. Move
misplaced startup_kdump where it belongs.

$ nm -n -S arch/s390/boot/compressed/vmlinux
Before:
0000000000010000 T startup
0000000000010010 T startup_kdump
After:
0000000000010000 0000000000000014 T startup
0000000000010014 00000000000000b0 t startup_normal
0000000000010180 00000000000000b2 t startup_kdump

Reviewed-by: Alexander Egorenkov <egorenar@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2020-11-20 19:19:11 +01:00
Vasily Gorbik
9a78c70a1b s390/decompressor: add decompressor_printk
The decompressor does not have any special debug means. Running the
kernel under qemu with gdb is helpful but tedious exercise if done
repeatedly. It is also not applicable to debugging under LPAR and z/VM.

One special thing which stands out is a working sclp_early_printk,
which could be used once the kernel switches to 64-bit addressing mode.

But sclp_early_printk does not provide any string formating capabilities.
Formatting and printing string without printk-alike function is a
not fun. The lack of printk-alike function means people would save up on
testing and introduce more bugs.

So, finally, provide decompressor_printk function, which fits on one
screen and trades features for simplicity.

It only supports "%s", "%x" and "%lx" specifiers and zero padding for
hex values.

Reviewed-by: Alexander Egorenkov <egorenar@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2020-11-20 19:19:11 +01:00
Vasily Gorbik
c9343637d6 s390/ftrace: assume -mhotpatch or -mrecord-mcount always available
Currently the kernel minimal compiler requirement is gcc 4.9 or
clang 10.0.1.
* gcc -mhotpatch option is supported since 4.8.
* A combination of -pg -mrecord-mcount -mnop-mcount -mfentry flags is
supported since gcc 9 and since clang 10.

Drop support for old -pg function prologues. Which leaves binary
compatible -mhotpatch / -mnop-mcount -mfentry prologues in a form:
	brcl	0,0
Which are also do not require initial nop optimization / conversion and
presence of _mcount symbol.

Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Reviewed-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2020-11-20 19:19:11 +01:00
Vasily Gorbik
73045a08cf s390: unify identity mapping limits handling
Currently we have to consider too many different values which
in the end only affect identity mapping size. These are:
1. max_physmem_end - end of physical memory online or standby.
   Always <= end of the last online memory block (get_mem_detect_end()).
2. CONFIG_MAX_PHYSMEM_BITS - the maximum size of physical memory the
   kernel is able to support.
3. "mem=" kernel command line option which limits physical memory usage.
4. OLDMEM_BASE which is a kdump memory limit when the kernel is executed as
   crash kernel.
5. "hsa" size which is a memory limit when the kernel is executed during
   zfcp/nvme dump.

Through out kernel startup and run we juggle all those values at once
but that does not bring any amusement, only confusion and complexity.

Unify all those values to a single one we should really care, that is
our identity mapping size.

Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com>
Acked-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2020-11-20 19:19:10 +01:00
Julian Wiedmann
1e632eaa0f s390/prng: let misc_register() add the prng sysfs attributes
Instead of creating the sysfs attributes for the prng devices by hand,
describe them in .groups and let the misdevice core handle it.

This also ensures that the attributes are available when the KOBJ_ADD
event is raised.

Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com>
Reviewed-by: Harald Freudenberger <freude@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2020-11-20 19:19:10 +01:00
Mauro Carvalho Chehab
5ec11d0966 s390/cio: fix kernel-doc markups in cio driver.
Fix typo in the kernel-doc markups
	1. ccw driver -> ccw_driver
	2. ccw_device_id_is_equal() -> ccw_dev_id_is_equal

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
[vneethv@linux.ibm.com: slight modification in the changelog]
Reviewed-by: Vineeth Vijayan <vneethv@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2020-11-20 19:19:10 +01:00
Heiko Carstens
0cd9b7230c s390: add separate program check exit path
System call and program check handler both use the system call exit
path when returning to previous context. However the program check
handler jumps right to the end of the system call exit path if the
previous context is kernel context.

This lead to the quite odd double disabling of interrupts in the
system call exit path introduced with commit ce9dfafe29be ("s390:
fix system call exit path").

To avoid that have a separate program check handler exit path if the
previous context is kernel context.

Reviewed-by: Sven Schnelle <svens@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2020-11-20 19:17:24 +01:00
Heiko Carstens
6c81603801 Merge branch 'fixes' into features
* fixes:
  s390/cpum_sf.c: fix file permission for cpum_sfb_size
  s390: update defconfigs
  s390: fix system call exit path

Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2020-11-20 19:15:58 +01:00
Sumanth Korikkar
b971cbd03e s390/sclp: provide extended sccb support
As the number of cpus increases, the sccb response can exceed 4k for
read cpu and read scp info sclp commands. Hence, all cpu info entries
cant be embedded within a sccb response

Solution:
To overcome this limitation, extended sccb facility is provided by sclp.

1. Check if the extended sccb facility is installed.
2. If extended sccb is installed, perform the read scp and read cpu
   command considering a max sccb length of three page size. This max
   length is based on factors like max cpus, sccb header.
3. If extended sccb is not installed, perform the read scp and read cpu
   sclp command considering a max sccb length of one page size.

Signed-off-by: Sumanth Korikkar <sumanthk@linux.ibm.com>
Reviewed-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2020-11-18 12:16:02 +01:00
Sumanth Korikkar
d25d23e134 s390/sclp: avoid copy of sclp_info_sccb
For extended sccb support, sccb size could be up to 3 pages. Hence avoid
copy of sclp_info_sccb.

Signed-off-by: Sumanth Korikkar <sumanthk@linux.ibm.com>
Reviewed-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2020-11-18 12:16:02 +01:00
Sumanth Korikkar
08ab919d0d s390/sclp: use memblock for early read cpu info
sclp early read cpu info is used to detect the number of configured
cpus, which is utilized by smp_detect_cpus() in early startup.

* For read cpu info, the sccb block should be below 2gb.
* smp_detect_cpus() utilizes read cpu info early, but after memblock
  initialization. Thus use memblock_allow_low() instead.
* Avoid copy of sclp_core_info structure.
* sclp_early_init_core_info(), sclp_early_core_info and
  sclp_early_core_info_valid initdata are no longer required.
* smp_get_core_info() is called only once during early stage.  Hence for
  early sclp_get_core_info(), directly call read cpu command. No need to
  maintain sclp_early_core_info_valid.

Signed-off-by: Sumanth Korikkar <sumanthk@linux.ibm.com>
Reviewed-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2020-11-18 12:16:02 +01:00
Niklas Schnelle
da78693e6e s390/pci: inform when missing required facilities
when we're missing the necessary machine facilities zPCI can
not function. Until now it would silently fail to be initialized,
add an informational print.

Signed-off-by: Niklas Schnelle <schnelle@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2020-11-18 12:16:02 +01:00
Heiko Carstens
ab177c5d00 s390/mm: remove unused clear_user_asce()
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2020-11-12 12:11:25 +01:00
Thomas Richter
78d732e1f3 s390/cpum_sf.c: fix file permission for cpum_sfb_size
This file is installed by the s390 CPU Measurement sampling
facility device driver to export supported minimum and
maximum sample buffer sizes.
This file is read by lscpumf tool to display the details
of the device driver capabilities. The lscpumf tool might
be invoked by a non-root user. In this case it does not
print anything because the file contents can not be read.

Fix this by allowing read access for all users. Reading
the file contents is ok, changing the file contents is
left to the root user only.

For further reference and details see:
 [1] https://github.com/ibm-s390-tools/s390-tools/issues/97

Fixes: 69f239ed335a ("s390/cpum_sf: Dynamically extend the sampling buffer if overflows occur")
Cc: <stable@vger.kernel.org> # 3.14
Signed-off-by: Thomas Richter <tmricht@linux.ibm.com>
Acked-by: Sumanth Korikkar <sumanthk@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2020-11-12 12:10:36 +01:00
Heiko Carstens
966e7ea434 s390: update defconfigs
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2020-11-12 12:10:36 +01:00
Harald Freudenberger
43cb5a7c61 s390/zcrypt/pkey: introduce zcrypt_wait_api_operational() function
The zcrypt api provides a new function to wait until the zcrypt
api is operational:

  int zcrypt_wait_api_operational(void);

The AP bus scan and the binding of ap devices to device drivers is
an asynchronous job. This function waits until these initial jobs
are done and so the zcrypt api should be ready to serve crypto
requests - if there are resources available. The function uses an
internal timeout of 60s. The very first caller will either wait for
ap bus bindings complete or the timeout happens. This state will be
remembered for further callers which will only be blocked until a
decision is made (timeout or bindings complete).

Reviewed-by: Ingo Franzki <ifranzki@linux.ibm.com>
Signed-off-by: Harald Freudenberger <freude@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2020-11-09 11:21:00 +01:00