Christophe Leroy [Mon, 31 Aug 2020 08:30:44 +0000 (08:30 +0000)]
powerpc/8xx: Support 16k hugepages with 4k pages
The 8xx has 4 page sizes: 4k, 16k, 512k and 8M
4k and 16k can be selected at build time as standard page sizes,
and 512k and 8M are hugepages.
When 4k standard pages are selected, 16k pages are not available.
Allow 16k pages as hugepages when 4k pages are used.
To allow that, implement arch_make_huge_pte() which receives
the necessary arguments to allow setting the PTE in accordance
with the page size:
- 512 k pages must have _PAGE_HUGE and _PAGE_SPS. They are set
by pte_mkhuge(). arch_make_huge_pte() does nothing.
- 16 k pages must have only _PAGE_SPS. arch_make_huge_pte() clears
_PAGE_HUGE.
Christophe Leroy [Mon, 31 Aug 2020 08:30:43 +0000 (08:30 +0000)]
powerpc/8xx: Refactor calculation of number of entries per PTE in page tables
On 8xx, the number of entries occupied by a PTE in the page tables
depends on the size of the page. At the time being, this calculation
is done in two places: in pte_update() and in set_huge_pte_at()
Refactor this calculation into a helper called
number_of_cells_per_pte(). For the time being, the val param is
unused. It will be used by following patch.
Instead of opencoding is_hugepd(), use hugepd_ok() with a forward
declaration.
This fault is due to hugetlb_free_pgd_range() freeing page tables
that are also used by regular pages.
As explain in the comment at the beginning of
hugetlb_free_pgd_range(), the verification done in free_pgd_range()
on floor and ceiling is not done here, which means
hugetlb_free_pte_range() can free outside the expected range.
As the verification cannot be done in hugetlb_free_pgd_range(), it
must be done in hugetlb_free_pte_range().
Resolve this problem by disabling each THRMn comparator when handling
the associated THRMn interrupt and by disabling the TAU entirely when
updating THRMn thresholds.
Finn Thain [Fri, 4 Sep 2020 23:02:20 +0000 (09:02 +1000)]
powerpc/tau: Check processor type before enabling TAU interrupt
According to Freescale's documentation, MPC74XX processors have an
erratum that prevents the TAU interrupt from working, so don't try to
use it when running on those processors.
The commentary at the call site seems to disagree with the code. The
conditional prevents calling set_thresholds() via the exception handler,
which appears to crash. Perhaps that's because it immediately triggers
another TAU exception. Anyway, calling set_thresholds() from TAUupdate()
is redundant because tau_timeout() does so.
Finn Thain [Fri, 4 Sep 2020 23:02:20 +0000 (09:02 +1000)]
powerpc/tau: Convert from timer to workqueue
Since commit 19dbdcb8039cf ("smp: Warn on function calls from softirq
context") the Thermal Assist Unit driver causes a warning like the
following when CONFIG_SMP is enabled.
Finn Thain [Fri, 4 Sep 2020 23:02:20 +0000 (09:02 +1000)]
powerpc/tau: Use appropriate temperature sample interval
According to the MPC750 Users Manual, the SITV value in Thermal
Management Register 3 is 13 bits long. The present code calculates the
SITV value as 60 * 500 cycles. This would overflow to give 10 us on
a 500 MHz CPU rather than the intended 60 us. (But according to the
Microprocessor Datasheet, there is also a factor of 266 that has to be
applied to this value on certain parts i.e. speed sort above 266 MHz.)
Always use the maximum cycle count, as recommended by the Datasheet.
powerpc/mm/book3s: Split radix and hash MAX_PHYSMEM limit
MAX_PHYSMEM #define is used along with sparsemem to determine the SECTION_SHIFT
value. Powerpc also uses the same value to limit the max memory enabled on the
system. With 4K PAGE_SIZE and hash translation mode, we want to limit the max
memory enabled to 64TB due to page table size restrictions. However, with
radix translation, we don't have these restrictions. Hence split the radix
and hash MA_PHYSMEM limit and use different limit for each of them.
powerpc/book3s64/hash/4k: Support large linear mapping range with 4K
With commit: 0034d395f89d ("powerpc/mm/hash64: Map all the kernel
regions in the same 0xc range"), we now split the 64TB address range
into 4 contexts each of 16TB. That implies we can do only 16TB linear
mapping.
On some systems, eg. Power9, memory attached to nodes > 0 will appear
above 16TB in the linear mapping. This resulted in kernel crash when
we boot such systems in hash translation mode with 4K PAGE_SIZE.
This patch updates the kernel mapping such that we now start supporting upto
61TB of memory with 4K. The kernel mapping now looks like below 4K PAGE_SIZE
and hash translation.
Our MAX_PHYSMEM_BITS for 4K is still 64TB even though we can only map 61TB.
We prevent bolt mapping anything outside 61TB range by checking against
H_VMALLOC_START.
powerpc/64/mm: implement page mapping percpu first chunk allocator
Implement page mapping percpu first chunk allocator as a fallback to
the embedding allocator. With 4K hash translation we limit our page
table range to 64TB and commit: 0034d395f89d ("powerpc/mm/hash64: Map all the
kernel regions in the same 0xc range") moved all kernel mapping to
that 64TB range. In-order to support sparse memory layout we need
to increase our linear mapping space and reduce other mappings.
With such a layout percpu embedded first chunk allocator will fail
because of small vmalloc range. Add a fallback to page mapping
percpu first chunk allocator for such failures.
The below dmesg output can be observed in such case.
percpu: max_distance=0x1ffffef00000 too large for vmalloc space 0x10000000000
PERCPU: auto allocator failed (-22), falling back to page size
percpu: 40 4K pages/cpu s148816 r0 d15024
Ravi Bangoria [Wed, 2 Sep 2020 04:29:45 +0000 (09:59 +0530)]
selftests/powerpc: Tests for kernel accessing user memory
Introduce tests to cover simple scenarios where user is watching
memory which can be accessed by kernel as well. We also support
_MODE_EXACT with _SETHWDEBUG interface. Move those testcases outside
of _BP_RANGE condition. This will help to test _MODE_EXACT scenarios
when CONFIG_HAVE_HW_BREAKPOINT is not set, eg:
$ ./ptrace-hwbreak
...
PTRACE_SET_DEBUGREG, Kernel Access Userspace, len: 8: Ok
PPC_PTRACE_SETHWDEBUG, MODE_EXACT, WO, len: 1: Ok
PPC_PTRACE_SETHWDEBUG, MODE_EXACT, RO, len: 1: Ok
PPC_PTRACE_SETHWDEBUG, MODE_EXACT, RW, len: 1: Ok
PPC_PTRACE_SETHWDEBUG, MODE_EXACT, Kernel Access Userspace, len: 1: Ok
success: ptrace-hwbreak
PPC_DEBUG_FEATURE_DATA_BP_ARCH_31 can be used to determine whether
we are running on an ISA 3.1 compliant machine. Which is needed to
determine DAR behaviour, 512 byte boundary limit etc. This was
requested by Pedro Miraglia Franco de Carvalho for extending
watchpoint features in gdb. Note that availability of 2nd DAWR is
independent of this flag and should be checked using
ppc_debug_info->num_data_bps.
Ravi Bangoria [Wed, 2 Sep 2020 04:29:43 +0000 (09:59 +0530)]
powerpc/watchpoint: Add hw_len wherever missing
There are couple of places where we set len but not hw_len. For
ptrace/perf watchpoints, when CONFIG_HAVE_HW_BREAKPOINT=Y, hw_len
will be calculated and set internally while parsing watchpoint.
But when CONFIG_HAVE_HW_BREAKPOINT=N, we need to manually set
'hw_len'. Similarly for xmon as well, hw_len needs to be set
directly.
Ravi Bangoria [Wed, 2 Sep 2020 04:29:42 +0000 (09:59 +0530)]
powerpc/watchpoint: Fix exception handling for CONFIG_HAVE_HW_BREAKPOINT=N
On powerpc, ptrace watchpoint works in one-shot mode. i.e. kernel
disables event every time it fires and user has to re-enable it.
Also, in case of ptrace watchpoint, kernel notifies ptrace user
before executing instruction.
With CONFIG_HAVE_HW_BREAKPOINT=N, kernel is missing to disable
ptrace event and thus it's causing infinite loop of exceptions.
This is especially harmful when user watches on a data which is
also read/written by kernel, eg syscall parameters. In such case,
infinite exceptions happens in kernel mode which causes soft-lockup.
Ravi Bangoria [Wed, 2 Sep 2020 04:29:41 +0000 (09:59 +0530)]
powerpc/watchpoint: Move DAWR detection logic outside of hw_breakpoint.c
Power10 hw has multiple DAWRs but hw doesn't tell which DAWR caused
the exception. So we have a sw logic to detect that in hw_breakpoint.c.
But hw_breakpoint.c gets compiled only with CONFIG_HAVE_HW_BREAKPOINT=Y.
Move DAWR detection logic outside of hw_breakpoint.c so that it can be
reused when CONFIG_HAVE_HW_BREAKPOINT is not set.
Ravi Bangoria [Wed, 2 Sep 2020 04:29:40 +0000 (09:59 +0530)]
powerpc/watchpoint/ptrace: Fix SETHWDEBUG when CONFIG_HAVE_HW_BREAKPOINT=N
When kernel is compiled with CONFIG_HAVE_HW_BREAKPOINT=N, user can
still create watchpoint using PPC_PTRACE_SETHWDEBUG, with limited
functionalities. But, such watchpoints are never firing because of
the missing privilege settings. Fix that.
It's safe to set HW_BRK_TYPE_PRIV_ALL because we don't really leak
any kernel address in signal info. Setting HW_BRK_TYPE_PRIV_ALL will
also help to find scenarios when kernel accesses user memory.
Ravi Bangoria [Wed, 2 Sep 2020 04:29:39 +0000 (09:59 +0530)]
powerpc/watchpoint: Fix handling of vector instructions
Vector load/store instructions are special because they are always
aligned. Thus unaligned EA needs to be aligned down before comparing
it with watch ranges. Otherwise we might consider valid event as
invalid.
Ravi Bangoria [Wed, 2 Sep 2020 04:29:38 +0000 (09:59 +0530)]
powerpc/watchpoint: Fix quadword instruction handling on p10 predecessors
On p10 predecessors, watchpoint with quadword access is compared at
quadword length. If the watch range is doubleword or less than that
in a first half of quadword aligned 16 bytes, and if there is any
unaligned quadword access which will access only the 2nd half, the
handler should consider it as extraneous and emulate/single-step it
before continuing.
powerpc/pseries/svm: Allocate SWIOTLB buffer anywhere in memory
POWER secure guests (i.e., guests which use the Protected Execution
Facility) need to use SWIOTLB to be able to do I/O with the
hypervisor, but they don't need the SWIOTLB memory to be in low
addresses since the hypervisor doesn't have any addressing limitation.
This solves a SWIOTLB initialization problem we are seeing in secure
guests with 128 GB of RAM: they are configured with 4 GB of
crashkernel reserved memory, which leaves no space for SWIOTLB in low
addresses.
To do this, we use mostly the same code as swiotlb_init(), but
allocate the buffer using memblock_alloc() instead of
memblock_alloc_low().
Michael Ellerman [Thu, 27 Aug 2020 13:17:13 +0000 (23:17 +1000)]
powerpc/64: Make VDSO32 track COMPAT on 64-bit
When we added the VDSO32 kconfig symbol, which controls building of
the 32-bit VDSO, we made it depend on CPU_BIG_ENDIAN (for 64-bit).
That was because back then COMPAT was always enabled for 64-bit, so
depending on it would have left the 32-bit VDSO always enabled, which
we didn't want.
But since then we have made COMPAT selectable, and off by default for
ppc64le, so VDSO32 should really depend on that.
For most people this makes no difference, none of the defconfigs
change, it's only if someone is building ppc64le with COMPAT=y, they
will now also get VDSO32. If they've enabled COMPAT in order to run
32-bit binaries they presumably also want the 32-bit VDSO.
powerpc/papr_scm: Limit the readability of 'perf_stats' sysfs attribute
The newly introduced 'perf_stats' attribute uses the default access
mode of 0444, allowing non-root users to access performance stats of
an nvdimm and potentially force the kernel into issuing a large number
of expensive hypercalls. Since the information exposed by this
attribute cannot be cached it is better to ward off access to this
attribute from users who don't need to access to these performance
statistics.
Hence update the access mode of 'perf_stats' attribute to be only
readable by root users.
Nicholas Piggin [Tue, 25 Aug 2020 07:55:35 +0000 (17:55 +1000)]
powerpc/64s: handle ISA v3.1 local copy-paste context switches
The ISA v3.1 the copy-paste facility has a new memory move functionality
which allows the copy buffer to be pasted to domestic memory (RAM) as
opposed to foreign memory (accelerator).
This means the POWER9 trick of avoiding the cp_abort on context switch if
the process had not mapped foreign memory does not work on POWER10. Do the
cp_abort unconditionally there.
KVM must also cp_abort on guest exit to prevent copy buffer state leaking
between contexts.
Joel Stanley [Wed, 2 Sep 2020 00:00:11 +0000 (09:30 +0930)]
powerpc: Warn about use of smt_snooze_delay
It's not done anything for a long time. Save the percpu variable, and
emit a warning to remind users to not expect it to do anything.
This uses pr_warn_once instead of pr_warn_ratelimit as testing
'ppc64_cpu --smt=off' on a 24 core / 4 SMT system showed the warning
to be noisy, as the online/offline loop is slow.
Leonardo Bras [Wed, 5 Aug 2020 03:04:55 +0000 (00:04 -0300)]
powerpc/pseries/iommu: Allow bigger 64bit window by removing default DMA window
On LoPAR "DMA Window Manipulation Calls", it's recommended to remove the
default DMA window for the device, before attempting to configure a DDW,
in order to make the maximum resources available for the next DDW to be
created.
This is a requirement for using DDW on devices in which hypervisor
allows only one DMA window.
If setting up a new DDW fails anywhere after the removal of this
default DMA window, it's needed to restore the default DMA window.
For this, an implementation of ibm,reset-pe-dma-windows rtas call is
needed:
Platforms supporting the DDW option starting with LoPAR level 2.7 implement
ibm,ddw-extensions. The first extension available (index 2) carries the
token for ibm,reset-pe-dma-windows rtas call, which is used to restore
the default DMA window for a device, if it has been deleted.
It does so by resetting the TCE table allocation for the PE to it's
boot time value, available in "ibm,dma-window" device tree node.
Leonardo Bras [Wed, 5 Aug 2020 03:04:54 +0000 (00:04 -0300)]
powerpc/pseries/iommu: Move window-removing part of remove_ddw into remove_dma_window
Move the window-removing part of remove_ddw into a new function
(remove_dma_window), so it can be used to remove other DMA windows.
It's useful for removing DMA windows that don't create DIRECT64_PROPNAME
property, like the default DMA window from the device, which uses
"ibm,dma-window".
Leonardo Bras [Wed, 5 Aug 2020 03:04:53 +0000 (00:04 -0300)]
powerpc/pseries/iommu: Update call to ibm, query-pe-dma-windows
>From LoPAR level 2.8, "ibm,ddw-extensions" index 3 can make the number of
outputs from "ibm,query-pe-dma-windows" go from 5 to 6.
This change of output size is meant to expand the address size of
largest_available_block PE TCE from 32-bit to 64-bit, which ends up
shifting page_size and migration_capable.
This ends up requiring the update of
ddw_query_response->largest_available_block from u32 to u64, and manually
assigning the values from the buffer into this struct, according to
output size.
Also, a routine was created for helping reading the ddw extensions as
suggested by LoPAR: First reading the size of the extension array from
index 0, checking if the property exists, and then returning it's value.
Russell Currey [Fri, 28 Aug 2020 02:05:42 +0000 (12:05 +1000)]
powerpc/tools: Remove 90 line limit in checkpatch script
As of commit bdc48fa11e46, scripts/checkpatch.pl now has a default line
length warning of 100 characters. The powerpc wrapper script was using
a length of 90 instead of 80 in order to make checkpatch less
restrictive, but now it's making it more restrictive instead.
I think it makes sense to just use the default value now.
Jordan Niethe [Mon, 24 Aug 2020 13:12:31 +0000 (23:12 +1000)]
selftests/powerpc: Fix prefixes in alignment_handler signal handler
The signal handler in the alignment handler self test has the ability
to jump over the instruction that triggered the signal. It does this
by incrementing the PT_NIP in the user context by 4. If it were a
prefixed instruction this will mean that the suffix is then executed
which is incorrect. Instead check if the major opcode indicates a
prefixed instruction (e.g. it is 1) and if so increment PT_NIP by 8.
If ISA v3.1 is not available treat it as a word instruction even if
the major opcode is 1.
Fixes: 620a6473df36 ("selftests/powerpc: Add prefixed loads/stores to alignment_handler test") Signed-off-by: Jordan Niethe <[email protected]>
[mpe: Fix 32-bit build, rename haveprefixes to prefixes_enabled] Signed-off-by: Michael Ellerman <[email protected]> Link: https://lore.kernel.org/r/[email protected]
Jordan Niethe [Tue, 25 Aug 2020 03:51:47 +0000 (13:51 +1000)]
powerpc/boot: Update Makefile comment for 64bit wrapper
As of commit 147c05168fc8 ("powerpc/boot: Add support for 64bit little
endian wrapper") the comment in the Makefile is misleading. The wrapper
packaging 64bit kernel may built as a 32 or 64 bit elf. Update the
comment to reflect this.
The last caller was removed in 2014 in commit fb5a515704d7 ("powerpc:
Remove platforms/wsp and associated pieces").
As Jordan noticed even though there are no callers, the code above in
fsl_secondary_thread_init() falls through into
generic_secondary_thread_init(). So we can remove the _GLOBAL but not
the body of the function.
However because fsl_secondary_thread_init() is inside #ifdef
CONFIG_PPC_BOOK3E, we can never reach the body of
generic_secondary_thread_init() unless CONFIG_PPC_BOOK3E is enabled,
so we can wrap the whole thing in a single #ifdef.
Michael Ellerman [Wed, 19 Aug 2020 01:57:27 +0000 (11:57 +1000)]
selftests/powerpc: Properly handle failure in switch_endian_test
On older CPUs the switch_endian() syscall doesn't work. Currently that
causes the switch_endian_test to just crash. Instead detect the
failure and properly exit with a failure message.
Michael Ellerman [Wed, 19 Aug 2020 01:57:26 +0000 (11:57 +1000)]
selftests/powerpc: Don't touch VMX/VSX on older CPUs
If we're running on a CPU without VMX/VSX then don't touch them. This
is fragile, the compiler could spill a VMX/VSX register and break the
test anyway. But in practice it seems to work, ie. the test runs to
completion on a system without VSX with this change.
Michael Ellerman [Wed, 19 Aug 2020 01:57:22 +0000 (11:57 +1000)]
selftests/powerpc: Include asm/cputable.h from utils.h
utils.h provides have_hwcap() and have_hwcap2() which check for a
feature bit. Those bits are defined in asm/cputable.h, so include it
in utils.h so users of utils.h don't have to do it manually.
Michael Ellerman [Wed, 19 Aug 2020 01:57:21 +0000 (11:57 +1000)]
selftests/powerpc: Move set_dscr() into rfi_flush.c
This version of set_dscr() was added for the RFI flush test, and is
fairly specific to it. It also clashes with the version of set_dscr()
in dscr/dscr.h. So move it into the RFI flush test where it's used.
Michael Ellerman [Thu, 13 Aug 2020 01:34:45 +0000 (11:34 +1000)]
selftests/powerpc: Run tm-tmspr test for longer
This test creates some threads, which write to TM SPRs, and then makes
sure the registers maintain the correct values across context switches
and contention with other threads.
But currently the test finishes almost instantaneously, which reduces
the chance of it hitting an interesting condition.
So increase the number of loops, so it runs a bit longer, though still
less than 2s on a Power8.
Michael Ellerman [Thu, 13 Aug 2020 01:34:44 +0000 (11:34 +1000)]
selftests/powerpc: Don't use setaffinity in tm-tmspr
This test tries to set affinity to CPUs that don't exist, especially
if the set of online CPUs doesn't start at 0.
But there's no real reason for it to use setaffinity in the first
place, it's just trying to create lots of threads to cause contention.
So drop the setaffinity entirely.
cpuidle: pseries: Fix CEDE latency conversion from tb to us
Commit d947fb4c965c ("cpuidle: pseries: Fixup exit latency for
CEDE(0)") sets the exit latency of CEDE(0) based on the latency values
of the Extended CEDE states advertised by the platform. The values
advertised by the platform are in timebase ticks. However the cpuidle
framework requires the latency values in microseconds.
If the tb-ticks value advertised by the platform correspond to a value
smaller than 1us, during the conversion from tb-ticks to microseconds,
in the current code, the result becomes zero. This is incorrect as it
puts a CEDE state on par with the snooze state.
This patch fixes this by rounding up the result obtained while
converting the latency value from tb-ticks to microseconds. It also
prints a warning in case we discover an extended-cede state with
wakeup latency to be 0. In such a case, ensure that CEDE(0) has a
non-zero wakeup latency.
There are 2 problems with it:
1. "<" vs expected "<<"
2. the shift number is an IOMMU page number mask, not an address
mask as the IOMMU page shift is missing.
This did not hit us before f1565c24b596 ("powerpc: use the generic
dma_ops_bypass mode") because we had additional code to handle bypass
mask so this chunk (almost?) never executed.However there were
reports that aacraid does not work with "iommu=nobypass".
After f1565c24b596, aacraid (and probably others which call
dma_get_required_mask() before setting the mask) was unable to enable
64bit DMA and fall back to using IOMMU which was known not to work,
one of the problems is double free of an IOMMU page.
This fixes DMA for aacraid, both with and without "iommu=nobypass" in
the kernel command line. Verified with "stress-ng -d 4".
Stephen Rothwell [Wed, 12 Aug 2020 08:10:36 +0000 (18:10 +1000)]
powerpc: unrel_branch_check.sh: enable the use of llvm-objdump v9, 10 or 11
Currently, using llvm-objtool, this script just silently succeeds without
actually do the intended checking. So this updates it to work properly.
Firstly, llvm-objdump does not add target symbol names to the end
of branches in its asm output, so we have to drop the branch to
__start_initialization_multiplatform using its address.
Secondly, v9 and 10 specify branch targets as .+<offset>, so we convert
those to actual addresses.
Thirdly, v10 and 11 error out on a vmlinux if given the -R option
complaining that it is "not a dynamic object". The -R does not make
any difference to the asm output, so remove it.
Lastly, v11 produces asm that is very similar to Gnu objtool (at least
as far as branches are concerned), so no further changes are necessary
to make it work.
Stephen Rothwell [Tue, 11 Aug 2020 14:04:31 +0000 (00:04 +1000)]
powerpc: unrel_branch_check.sh: convert grep | sed | awk to just sed
Also start using sed -E and make all the separate expressions into a
single one with comments. Pull the stripping of condition registers
back into the sed command.
Scott Cheloha [Tue, 11 Aug 2020 01:51:15 +0000 (20:51 -0500)]
pseries/drmem: don't cache node id in drmem_lmb struct
At memory hot-remove time we can retrieve an LMB's nid from its
corresponding memory_block. There is no need to store the nid
in multiple locations.
Note that lmb_to_memblock() uses find_memory_block() to get the
corresponding memory_block. As find_memory_block() runs in sub-linear
time this approach is negligibly slower than what we do at present.
In exchange for this lookup at hot-remove time we no longer need to
call memory_add_physaddr_to_nid() during drmem_init() for each LMB.
On powerpc, memory_add_physaddr_to_nid() is a linear search, so this
spares us an O(n^2) initialization during boot.
On systems with many LMBs that initialization overhead is palpable and
disruptive. For example, on a box with 249854 LMBs we're seeing
drmem_init() take upwards of 30 seconds to complete:
With a patched kernel on the same machine we're no longer seeing the
soft lockup. drmem_init() now completes in negligible time, even when
the LMB count is large.
Nathan Lynch [Thu, 13 Aug 2020 15:11:31 +0000 (10:11 -0500)]
powerpc/pseries: explicitly reschedule during drmem_lmb list traversal
The drmem lmb list can have hundreds of thousands of entries, and
unfortunately lookups take the form of linear searches. As long as
this is the case, traversals have the potential to monopolize the CPU
and provoke lockup reports, workqueue stalls, and the like unless
they explicitly yield.
Rather than placing cond_resched() calls within various
for_each_drmem_lmb() loop blocks in the code, put it in the iteration
expression of the loop macro itself so users can't omit it.
Introduce a drmem_lmb_next() iteration helper function which calls
cond_resched() at a regular interval during array traversal. Each
iteration of the loop in DLPAR code paths can involve around ten RTAS
calls which can each take up to 250us, so this ensures the check is
performed at worst every few milliseconds.
Stephen Kitt [Fri, 7 Aug 2020 15:27:13 +0000 (17:27 +0200)]
powerpc: Use simple i2c probe function
The i2c probe functions here don't use the id information provided in
their second argument, so the single-parameter i2c probe
function ("probe_new") can be used instead.
This avoids scanning the identifier tables during probes.
Scott Cheloha [Mon, 27 Jul 2020 18:46:05 +0000 (13:46 -0500)]
powerpc/pseries: new lparcfg key/value pair: partition_affinity_score
The H_GetPerformanceCounterInfo (GPCI) PHYP hypercall has a subcall,
Affinity_Domain_Info_By_Partition, which returns, among other things,
a "partition affinity score" for a given LPAR. This score, a value on
[0-100], represents the processor-memory affinity for the LPAR in
question. A score of 0 indicates the worst possible affinity while a
score of 100 indicates perfect affinity. The score can be used to
reason about performance.
This patch adds the score for the local LPAR to the lparcfg procfile
under a new 'partition_affinity_score' key.
Scott Cheloha [Mon, 27 Jul 2020 18:46:04 +0000 (13:46 -0500)]
powerpc/perf: consolidate GPCI hcall structs into asm/hvcall.h
The H_GetPerformanceCounterInfo (GPCI) hypercall input/output structs are
useful to modules outside of perf/, so move them into asm/hvcall.h to live
alongside the other powerpc hypercall structs.
Leave the perf-specific GPCI stuff in perf/hv-gpci.h.
There are spelling mistakes in two debug messages. As recommended
by Wolfram Sang, these can be removed as there is plenty of debug
in the driver core.
The assembler says:
arch/powerpc/kernel/head_32.S:1095: Warning: invalid register expression
It's objecting to the use of r0 as the RA argument. That's because
when RA = 0 the literal value 0 is used, rather than the content of
r0, making the use of r0 in the source potentially confusing.
Fix it to use a literal 0, the generated code is identical.
selftests/powerpc: Skip PROT_SAO test in guests/LPARS
In commit 9b725a90a8f1 ("powerpc/64s: Disallow PROT_SAO in LPARs by
default") PROT_SAO was disabled in guests/LPARs by default. So skip
the test if we are running in a guest to avoid a spurious failure.
powerpc/book3s64/radix: Fix boot failure with large amount of guest memory
If the hypervisor doesn't support hugepages, the kernel ends up allocating a large
number of page table pages. The early page table allocation was wrongly
setting the max memblock limit to ppc64_rma_size with radix translation
which resulted in boot failure as shown below.
This was because the kernel was checking for the radix feature before we enable the
feature via mmu_features. This resulted in the kernel using hash restrictions on
radix.
Rework the early init code such that the kernel boot with memblock restrictions
as imposed by hash. At that point, the kernel still hasn't finalized the
translation the kernel will end up using.
We have three different ways of detecting radix.
1. dt_cpu_ftrs_scan -> used only in case of PowerNV
2. ibm,pa-features -> Used when we don't use cpu_dt_ftr_scan
3. CAS -> Where we negotiate with hypervisor about the supported translation.
We look at 1 or 2 early in the boot and after that, we look at the CAS vector to
finalize the translation the kernel will use. We also support a kernel command
line option (disable_radix) to switch to hash.
Update the memblock limit after mmu_early_init_devtree() if the kernel is going
to use radix translation. This forces some of the memblock allocations we do before
mmu_early_init_devtree() to be within the RMA limit.
Revert "powerpc/powernv/idle: Replace CPU feature check with PVR check"
cpuidle stop state implementation has minor optimizations for P10
where hardware preserves more SPR registers compared to P9. The
current P9 driver works for P10, although does few extra
save-restores. P9 driver can provide the required power management
features like SMT thread folding and core level power savings on a P10
platform.
Until the P10 stop driver is available, revert the commit which allows
for only P9 systems to utilize cpuidle and blocks all idle stop states
for P10. CPU idle states are enabled and tested on the P10 platform
with this fix.
Athira Rajeev [Wed, 26 Aug 2020 06:40:29 +0000 (02:40 -0400)]
powerpc/perf: Fix reading of MSR[HV/PR] bits in trace-imc
IMC trace-mode uses MSR[HV/PR] bits to set the cpumode for the
instruction pointer captured in each sample. The bits are fetched from
the third double word of the trace record. Reading third double word
from IMC trace record should use be64_to_cpu() along with READ_ONCE
inorder to fetch correct MSR[HV/PR] bits. Patch addresses this change.
Currently we are using PERF_RECORD_MISC_HYPERVISOR as cpumode if MSR
HV is 1 and PR is 0 which means the address is from host counter. But
using PERF_RECORD_MISC_HYPERVISOR for host counter data will fail to
resolve the address -> symbol during "perf report" because perf tools
side uses PERF_RECORD_MISC_KERNEL to represent the host counter data.
Therefore, fix the trace imc sample data to use
PERF_RECORD_MISC_KERNEL as cpumode for host kernel information.
powerpc/perf: Fix crashes with generic_compat_pmu & BHRB
The bhrb_filter_map ("The Branch History Rolling Buffer") callback is
only defined in raw CPUs' power_pmu structs. The "architected" CPUs
use generic_compat_pmu, which does not have this callback, and crashes
occur if a user tries to enable branch stack for an event.
This add a NULL pointer check for bhrb_filter_map() which behaves as
if the callback returned an error.
This does not add the same check for config_bhrb() as the only caller
checks for cpuhw->bhrb_users which remains zero if bhrb_filter_map==0.
Michael Ellerman [Tue, 25 Aug 2020 09:34:24 +0000 (19:34 +1000)]
powerpc/64s: Fix crash in load_fp_state() due to fpexc_mode
The recent commit 01eb01877f33 ("powerpc/64s: Fix restore_math
unnecessarily changing MSR") changed some of the handling of floating
point/vector restore.
In particular it caused current->thread.fpexc_mode to be copied into
the current MSR (via msr_check_and_set()), rather than just into
regs->msr (which is moved into MSR on return to userspace).
This can lead to a crash in the kernel if we take a floating point
exception when restoring FPSCR:
Fix it by only loading the fpexc_mode value into regs->msr.
Also add a comment to explain that although VSX is subject to the
value of fpexc_mode, we don't have to handle that separately because
we only allow VSX to be enabled if FP is also enabled.
Randy Dunlap [Mon, 24 Aug 2020 00:31:16 +0000 (17:31 -0700)]
Documentation/powerpc: fix malformed table in syscall64-abi
Fix malformed table warning in powerpc/syscall64-abi.rst by making
two tables and moving the headings.
Documentation/powerpc/syscall64-abi.rst:53: WARNING: Malformed table.
Text in column margin in table line 2.
=========== ============= ========================================
--- For the sc instruction, differences with the ELF ABI ---
r0 Volatile (System call number.)
r3 Volatile (Parameter 1, and return value.)
r4-r8 Volatile (Parameters 2-6.)
cr0 Volatile (cr0.SO is the return error condition.)
cr1, cr5-7 Nonvolatile
lr Nonvolatile
--- For the scv 0 instruction, differences with the ELF ABI ---
r0 Volatile (System call number.)
r3 Volatile (Parameter 1, and return value.)
r4-r8 Volatile (Parameters 2-6.)
=========== ============= ========================================
Michael Ellerman [Fri, 21 Aug 2020 10:49:10 +0000 (20:49 +1000)]
video: fbdev: controlfb: Fix build for COMPILE_TEST=y && PPC_PMAC=n
The build is currently broken, if COMPILE_TEST=y and PPC_PMAC=n:
linux/drivers/video/fbdev/controlfb.c: In function ‘control_set_hardware’:
linux/drivers/video/fbdev/controlfb.c:276:2: error: implicit declaration of function ‘btext_update_display’
276 | btext_update_display(p->frame_buffer_phys + CTRLFB_OFF,
| ^~~~~~~~~~~~~~~~~~~~
Fix it by including btext.h whenever CONFIG_BOOTX_TEXT is enabled.
Building with W=1 results in the following warning:
In file included from arch/powerpc/platforms/powernv/vas-fault.c:16:
./arch/powerpc/include/asm/icswx.h:159:1: error: alignment 1 of ‘struct
coprocessor_request_block’ is less than 16 [-Werror=packed-not-aligned]
159 | } __packed;
| ^
./arch/powerpc/include/asm/icswx.h:159:1: error: alignment 1 of ‘struct
coprocessor_request_block’ is less than 16 [-Werror=packed-not-aligned]
./arch/powerpc/include/asm/icswx.h:159:1: error: alignment 1 of ‘struct
coprocessor_request_block’ is less than 16 [-Werror=packed-not-aligned]
./arch/powerpc/include/asm/icswx.h:159:1: error: alignment 1 of ‘struct
coprocessor_request_block’ is less than 16 [-Werror=packed-not-aligned]
cc1: all warnings being treated as errors
This happens because coprocessor_request_block includes several
sub-structures with an alignment specified using the __aligned(XX)
attribute. The problem comes from coprocessor_request_block having the
__packed attribute. Packing the structure causes the preferred alignment of
the nested structures to be ignored and we get the warnings as a result.
This isn't a problem in practice since the struct is defined with explicit
padding in the form of reserved fields, but we'd like to get rid of the
spurious warnings. The simplest solution is to remove the packed attribute
and use a BUILD_BUG_ON() to ensure the struct is the correct (expected by
HW) size compile time.
Also add a __aligned(128) to the request block structure since Book4 for P8
suggests the HW requires it to be aligned to a 128 byte boundary. There's a
similar requirement for P9 since the COPY and PASTE instructions used to
invoke VAS/NX accelerators operates on a cache line boundary.
powerpc/powernv: Fix spurious kerneldoc warnings in opal-prd.c
Comments opening with /** are parsed by kerneldoc and this causes the
following warning to be printed:
arch/powerpc/platforms/powernv/opal-prd.c:31: warning: cannot understand
function prototype: 'struct opal_prd_msg_queue_item '
opal_prd_mesg_queue_item is an internal data structure so there's no real
need for it to be documented at all. Fix up the comment to squash the
warning.
powerpc/powernv: Include asm/powernv.h from the local powernv.h
The asm/powernv.h header provides prototypes for functions which need to be
called by non-powernv platform code. Also include it in the powernv.h
that's local to the platform directory to squash some warnings about
non-static functions missing prototypes.
Also include powernv.h since from opal-memcons.c since it has the
prototypes for the memcons wrangling functions which are used for the opal
and ultravisor msglog.
When building with W=1 we get the following warning:
arch/powerpc/platforms/powernv/smp.c: In function ‘pnv_smp_cpu_kill_self’:
arch/powerpc/platforms/powernv/smp.c:276:16: error: suggest braces around
empty body in an ‘if’ statement [-Werror=empty-body]
276 | cpu, srr1);
| ^
cc1: all warnings being treated as errors
The full context is this block:
if (srr1 && !generic_check_cpu_restart(cpu))
DBG("CPU%d Unexpected exit while offline srr1=%lx!\n",
cpu, srr1);
When building with DEBUG undefined DBG() expands to nothing and GCC emits
the warning due to the lack of braces around an empty statement.
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