This hypervisor's call allows to remove up to 8 ptes with only call to
tlbie.
The virtual pages must be all within the same naturally aligned 8 pages
virtual address block and have the same page and segment size encodings.
Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.ibm.com>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Laurent Dufour <ldufour@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
This part of code will be called also when dealing with H_BLOCK_REMOVE.
Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.ibm.com>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Signed-off-by: Laurent Dufour <ldufour@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
asm/tlbflush.h is only needed for:
- using functions xxx_flush_tlb_xxx()
- using MMU_NO_CONTEXT
- including asm-generic/pgtable.h
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
This patch adds error reporting to H_ENTER and H_READ hcalls. A
failure for both these hcalls are mostly fatal and it would be good to
log the failure reason.
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
[mpe: Split out of larger patch]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Switch from printk to pr_fmt() / pr_xxx().
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
[mpe: Split out of larger patch]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
The hcall_exit() tracepoint has retval defined as unsigned long. That
leads to humours results like:
bash-3686 [009] d..2 854.134094: hcall_entry: opcode=24
bash-3686 [009] d..2 854.134095: hcall_exit: opcode=24 retval=18446744073709551609
It's normal for some hcalls to return negative values, displaying them
as unsigned isn't very helpful. So change it to signed.
bash-3711 [001] d..2 471.691008: hcall_entry: opcode=24
bash-3711 [001] d..2 471.691008: hcall_exit: opcode=24 retval=-7
Which can be more easily compared to H_NOT_FOUND in hvcall.h
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Acked-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Tested-by: Ravi Bangoria <ravi.bangoria@linux.ibm.com>
Bring in yet another series that touches KVM code, and might need to
be merged into the kvm-ppc branch to resolve conflicts.
This required some changes in pnv_power9_force_smt4_catch/release()
due to the paca array becomming an array of pointers.
Change the paca array into an array of pointers to pacas. Allocate
pacas individually.
This allows flexibility in where the PACAs are allocated. Future work
will allocate them node-local. Platforms that don't have address limits
on PACAs would be able to defer PACA allocations until later in boot
rather than allocate all possible ones up-front then freeing unused.
This is slightly more overhead (one additional indirection) for cross
CPU paca references, but those aren't too common.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
With enabled DEBUG, there is a compile error:
"error: ‘flags’ is used uninitialized in this function".
This moves pr_devel() little further where @flags are initialized.
Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
On POWER9, since commit cc3d294013 ("powerpc/64: Enable use of radix
MMU under hypervisor on POWER9", 2017-01-30), we set both the radix and
HPT bits in the client-architecture-support (CAS) vector, which tells
the hypervisor that we can do either radix or HPT. According to PAPR,
if we use this combination we are promising to do a H_REGISTER_PROC_TBL
hcall later on to let the hypervisor know whether we are doing radix
or HPT. We currently do this call if we are doing radix but not if
we are doing HPT. If the hypervisor is able to support both radix
and HPT guests, it would be entitled to defer allocation of the HPT
until the H_REGISTER_PROC_TBL call, and to fail any attempts to create
HPTEs until the H_REGISTER_PROC_TBL call. Thus we need to do a
H_REGISTER_PROC_TBL call when we are doing HPT; otherwise we may
crash at boot time.
This adds the code to call H_REGISTER_PROC_TBL in this case, before
we attempt to create any HPT entries using H_ENTER.
Fixes: cc3d294013 ("powerpc/64: Enable use of radix MMU under hypervisor on POWER9")
Cc: stable@vger.kernel.org # v4.11+
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
Reviewed-by: Suraj Jitindar Singh <sjitindarsingh@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
CONFIG_PPC_STD_MMU_64 indicates support for the "standard" powerpc MMU
on 64-bit CPUs. The "standard" MMU refers to the hash page table MMU
found in "server" processors, from IBM mainly.
Currently CONFIG_PPC_STD_MMU_64 is == CONFIG_PPC_BOOK3S_64. While it's
annoying to have two symbols that always have the same value, it's not
quite annoying enough to bother removing one.
However with the arrival of Power9, we now have the situation where
CONFIG_PPC_STD_MMU_64 is enabled, but the kernel is running using the
Radix MMU - *not* the "standard" MMU. So it is now actively confusing
to use it, because it implies that code is disabled or inactive when
the Radix MMU is in use, however that is not necessarily true.
So s/CONFIG_PPC_STD_MMU_64/CONFIG_PPC_BOOK3S_64/, and do some minor
formatting updates of some of the affected lines.
This will be a pain for backports, but c'est la vie.
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Once upon a time there were only two PP (page protection) bits. In ISA
2.03 an additional PP bit was added, but because of the layout of the
HPTE it could not be made contiguous with the existing PP bits.
The result is that we now have three PP bits, named pp0, pp1, pp2,
where pp0 occupies bit 63 of dword 1 of the HPTE and pp1 and pp2
occupy bits 1 and 0 respectively. Until recently Linux hasn't used
pp0, however with the addition of _PAGE_KERNEL_RO we started using it.
The problem arises in the LPAR code, where we need to translate the PP
bits into the argument for the H_PROTECT hypercall. Currently the code
only passes bits 0-2 of newpp, which covers pp1, pp2 and N (no
execute), meaning pp0 is not passed to the hypervisor at all.
We can't simply pass it through in bit 63, as that would collide with a
different field in the flags argument, as defined in PAPR. Instead we
have to shift it down to bit 8 (IBM bit 55).
Fixes: e58e87adc8 ("powerpc/mm: Update _PAGE_KERNEL_RO")
Cc: stable@vger.kernel.org # v4.7+
Signed-off-by: Balbir Singh <bsingharora@gmail.com>
[mpe: Simplify the test, rework change log]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Now that we use all the available virtual address range, we need to make
sure we don't generate VSID such that it overlaps with the reserved vsid
range. Reserved vsid range include the virtual address range used by the
adjunct partition and also the VRMA virtual segment. We find the context
value that can result in generating such a VSID and reserve it early in
boot.
We don't look at the adjunct range, because for now we disable the
adjunct usage in a Linux LPAR via CAS interface.
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
[mpe: Rewrite hash__reserve_context_id(), move the rest into pseries]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
As of commit 438cc81a41 ("powerpc/pseries: Automatically resize HPT
for memory hot add/remove"), when running on the pseries platform, we
always attempt to use the PAPR extension to resize the hashed page
table (HPT) when we add or remove memory.
This is fine, but when the extension is not available we'll give a
harmless, but scary warning. Instead check if the firmware supports HPT
resizing before populating the mmu_hash_ops.resize_hpt pointer.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
This adds support for using two hypercalls to change the size of the
main hash page table while running as a PAPR guest. For now these
hypercalls are only in experimental qemu versions.
The interface is two part: first H_RESIZE_HPT_PREPARE is used to
allocate and prepare the new hash table. This may be slow, but can be
done asynchronously. Then, H_RESIZE_HPT_COMMIT is used to switch to the
new hash table. This requires that no CPUs be concurrently updating the
HPT, and so must be run under stop_machine().
This also adds a debugfs file which can be used to manually control
HPT resizing or testing purposes.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Reviewed-by: Paul Mackerras <paulus@samba.org>
[mpe: Rename the debugfs file to "hpt_order"]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
To use radix as a guest, we first need to tell the hypervisor via
the ibm,client-architecture call first that we support POWER9 and
architecture v3.00, and that we can do either radix or hash and
that we would like to choose later using an hcall (the
H_REGISTER_PROC_TBL hcall).
Then we need to check whether the hypervisor agreed to us using
radix. We need to do this very early on in the kernel boot process
before any of the MMU initialization is done. If the hypervisor
doesn't agree, we can't use radix and therefore clear the radix
MMU feature bit.
Later, when we have set up our process table, which points to the
radix tree for each process, we need to install that using the
H_REGISTER_PROC_TBL hcall.
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Highlights include:
- Support for the kexec_file_load() syscall, which is a prereq for secure and
trusted boot.
- Prevent kernel execution of userspace on P9 Radix (similar to SMEP/PXN).
- Sort the exception tables at build time, to save time at boot, and store
them as relative offsets to save space in the kernel image & memory.
- Allow building the kernel with thin archives, which should allow us to build
an allyesconfig once some other fixes land.
- Build fixes to allow us to correctly rebuild when changing the kernel endian
from big to little or vice versa.
- Plumbing so that we can avoid doing a full mm TLB flush on P9 Radix.
- Initial stack protector support (-fstack-protector).
- Support for dumping the radix (aka. Linux) and hash page tables via debugfs.
- Fix an oops in cxl coredump generation when cxl_get_fd() is used.
- Freescale updates from Scott: "Highlights include 8xx hugepage support,
qbman fixes/cleanup, device tree updates, and some misc cleanup."
- Many and varied fixes and minor enhancements as always.
Thanks to:
Alexey Kardashevskiy, Andrew Donnellan, Aneesh Kumar K.V, Anshuman Khandual,
Anton Blanchard, Balbir Singh, Bartlomiej Zolnierkiewicz, Christophe Jaillet,
Christophe Leroy, Denis Kirjanov, Elimar Riesebieter, Frederic Barrat,
Gautham R. Shenoy, Geliang Tang, Geoff Levand, Jack Miller, Johan Hovold,
Lars-Peter Clausen, Libin, Madhavan Srinivasan, Michael Neuling, Nathan
Fontenot, Naveen N. Rao, Nicholas Piggin, Pan Xinhui, Peter Senna Tschudin,
Rashmica Gupta, Rui Teng, Russell Currey, Scott Wood, Simon Guo, Suraj
Jitindar Singh, Thiago Jung Bauermann, Tobias Klauser, Vaibhav Jain.
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Merge tag 'powerpc-4.10-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux
Pull powerpc updates from Michael Ellerman:
"Highlights include:
- Support for the kexec_file_load() syscall, which is a prereq for
secure and trusted boot.
- Prevent kernel execution of userspace on P9 Radix (similar to
SMEP/PXN).
- Sort the exception tables at build time, to save time at boot, and
store them as relative offsets to save space in the kernel image &
memory.
- Allow building the kernel with thin archives, which should allow us
to build an allyesconfig once some other fixes land.
- Build fixes to allow us to correctly rebuild when changing the
kernel endian from big to little or vice versa.
- Plumbing so that we can avoid doing a full mm TLB flush on P9
Radix.
- Initial stack protector support (-fstack-protector).
- Support for dumping the radix (aka. Linux) and hash page tables via
debugfs.
- Fix an oops in cxl coredump generation when cxl_get_fd() is used.
- Freescale updates from Scott: "Highlights include 8xx hugepage
support, qbman fixes/cleanup, device tree updates, and some misc
cleanup."
- Many and varied fixes and minor enhancements as always.
Thanks to:
Alexey Kardashevskiy, Andrew Donnellan, Aneesh Kumar K.V, Anshuman
Khandual, Anton Blanchard, Balbir Singh, Bartlomiej Zolnierkiewicz,
Christophe Jaillet, Christophe Leroy, Denis Kirjanov, Elimar
Riesebieter, Frederic Barrat, Gautham R. Shenoy, Geliang Tang, Geoff
Levand, Jack Miller, Johan Hovold, Lars-Peter Clausen, Libin,
Madhavan Srinivasan, Michael Neuling, Nathan Fontenot, Naveen N.
Rao, Nicholas Piggin, Pan Xinhui, Peter Senna Tschudin, Rashmica
Gupta, Rui Teng, Russell Currey, Scott Wood, Simon Guo, Suraj
Jitindar Singh, Thiago Jung Bauermann, Tobias Klauser, Vaibhav Jain"
[ And thanks to Michael, who took time off from a new baby to get this
pull request done. - Linus ]
* tag 'powerpc-4.10-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: (174 commits)
powerpc/fsl/dts: add FMan node for t1042d4rdb
powerpc/fsl/dts: add sg_2500_aqr105_phy4 alias on t1024rdb
powerpc/fsl/dts: add QMan and BMan nodes on t1024
powerpc/fsl/dts: add QMan and BMan nodes on t1023
soc/fsl/qman: test: use DEFINE_SPINLOCK()
powerpc/fsl-lbc: use DEFINE_SPINLOCK()
powerpc/8xx: Implement support of hugepages
powerpc: get hugetlbpage handling more generic
powerpc: port 64 bits pgtable_cache to 32 bits
powerpc/boot: Request no dynamic linker for boot wrapper
soc/fsl/bman: Use resource_size instead of computation
soc/fsl/qe: use builtin_platform_driver
powerpc/fsl_pmc: use builtin_platform_driver
powerpc/83xx/suspend: use builtin_platform_driver
powerpc/ftrace: Fix the comments for ftrace_modify_code
powerpc/perf: macros for power9 format encoding
powerpc/perf: power9 raw event format encoding
powerpc/perf: update attribute_group data structure
powerpc/perf: factor out the event format field
powerpc/mm/iommu, vfio/spapr: Put pages on VFIO container shutdown
...
o STM can hook into the function tracer
o Function filtering now supports more advance glob matching
o Ftrace selftests updates and added tests
o Softirq tag in traces now show only softirqs
o ARM nop added to non traced locations at compile time
o New trace_marker_raw file that allows for binary input
o Optimizations to the ring buffer
o Removal of kmap in trace_marker
o Wakeup and irqsoff tracers now adhere to the set_graph_notrace file
o Other various fixes and clean ups
Note, there are two patches marked for stable. These were discovered
near the end of the 4.9 rc release cycle. By the time I had them tested
it was just a matter of days before 4.9 would be released, and I
figured I would just submit them in the merge window. They are old
bugs and not critical. Nothing non-root could abuse.
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Merge tag 'trace-v4.10' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace
Pull tracing updates from Steven Rostedt:
"This release has a few updates:
- STM can hook into the function tracer
- Function filtering now supports more advance glob matching
- Ftrace selftests updates and added tests
- Softirq tag in traces now show only softirqs
- ARM nop added to non traced locations at compile time
- New trace_marker_raw file that allows for binary input
- Optimizations to the ring buffer
- Removal of kmap in trace_marker
- Wakeup and irqsoff tracers now adhere to the set_graph_notrace file
- Other various fixes and clean ups"
* tag 'trace-v4.10' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: (42 commits)
selftests: ftrace: Shift down default message verbosity
kprobes/trace: Fix kprobe selftest for newer gcc
tracing/kprobes: Add a helper method to return number of probe hits
tracing/rb: Init the CPU mask on allocation
tracing: Use SOFTIRQ_OFFSET for softirq dectection for more accurate results
tracing/fgraph: Have wakeup and irqsoff tracers ignore graph functions too
fgraph: Handle a case where a tracer ignores set_graph_notrace
tracing: Replace kmap with copy_from_user() in trace_marker writing
ftrace/x86_32: Set ftrace_stub to weak to prevent gcc from using short jumps to it
tracing: Allow benchmark to be enabled at early_initcall()
tracing: Have system enable return error if one of the events fail
tracing: Do not start benchmark on boot up
tracing: Have the reg function allow to fail
ring-buffer: Force rb_end_commit() and rb_set_commit_to_write() inline
ring-buffer: Froce rb_update_write_stamp() to be inlined
ring-buffer: Force inline of hotpath helper functions
tracing: Make __buffer_unlock_commit() always_inline
tracing: Make tracepoint_printk a static_key
ring-buffer: Always inline rb_event_data()
ring-buffer: Make rb_reserve_next_event() always inlined
...
Some tracepoints have a registration function that gets enabled when the
tracepoint is enabled. There may be cases that the registraction function
must fail (for example, can't allocate enough memory). In this case, the
tracepoint should also fail to register, otherwise the user would not know
why the tracepoint is not working.
Cc: David Howells <dhowells@redhat.com>
Cc: Seiji Aguchi <seiji.aguchi@hds.com>
Cc: Anton Blanchard <anton@samba.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
This changes the way that we support the new ISA v3.00 HPTE format.
Instead of adapting everything that uses HPTE values to handle either
the old format or the new format, depending on which CPU we are on,
we now convert explicitly between old and new formats if necessary
in the low-level routines that actually access HPTEs in memory.
This limits the amount of code that needs to know about the new
format and makes the conversions explicit. This is OK because the
old format contains all the information that is in the new format.
This also fixes operation under a hypervisor, because the H_ENTER
hypercall (and other hypercalls that deal with HPTEs) will continue
to require the HPTE value to be supplied in the old format. At
present the kernel will not boot in HPT mode on POWER9 under a
hypervisor.
This fixes and partially reverts commit 50de596de8
("powerpc/mm/hash: Add support for Power9 Hash", 2016-04-29).
Fixes: 50de596de8 ("powerpc/mm/hash: Add support for Power9 Hash")
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
An hcall was recently added that does exactly what we need during kexec
- it clears the entire MMU hash table, ignoring any VRMA mappings.
Try it and fall back to the old method if we get a failure.
On a POWER8 box with 5TB of memory, this reduces the time it takes to
kexec a new kernel from from 4 minutes to 1 minute.
Signed-off-by: Anton Blanchard <anton@samba.org>
Tested-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com>
[mpe: Split into separate functions and tweak function naming]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
This commit fixes a stack corruption in the pseries specific code dealing
with the huge pages.
In __pSeries_lpar_hugepage_invalidate() the buffer used to pass arguments
to the hypervisor is not large enough. This leads to a stack corruption
where a previously saved register could be corrupted leading to unexpected
result in the caller, like the following panic:
Oops: Kernel access of bad area, sig: 11 [#1]
SMP NR_CPUS=2048 NUMA pSeries
Modules linked in: virtio_balloon ip_tables x_tables autofs4
virtio_blk 8139too virtio_pci virtio_ring 8139cp virtio
CPU: 11 PID: 1916 Comm: mmstress Not tainted 4.8.0 #76
task: c000000005394880 task.stack: c000000005570000
NIP: c00000000027bf6c LR: c00000000027bf64 CTR: 0000000000000000
REGS: c000000005573820 TRAP: 0300 Not tainted (4.8.0)
MSR: 8000000000009033 <SF,EE,ME,IR,DR,RI,LE> CR: 84822884 XER: 20000000
CFAR: c00000000010a924 DAR: 420000000014e5e0 DSISR: 40000000 SOFTE: 1
GPR00: c00000000027bf64 c000000005573aa0 c000000000e02800 c000000004447964
GPR04: c00000000404de18 c000000004d38810 00000000042100f5 00000000f5002104
GPR08: e0000000f5002104 0000000000000001 042100f5000000e0 00000000042100f5
GPR12: 0000000000002200 c00000000fe02c00 c00000000404de18 0000000000000000
GPR16: c1ffffffffffe7ff 00003fff62000000 420000000014e5e0 00003fff63000000
GPR20: 0008000000000000 c0000000f7014800 0405e600000000e0 0000000000010000
GPR24: c000000004d38810 c000000004447c10 c00000000404de18 c000000004447964
GPR28: c000000005573b10 c000000004d38810 00003fff62000000 420000000014e5e0
NIP [c00000000027bf6c] zap_huge_pmd+0x4c/0x470
LR [c00000000027bf64] zap_huge_pmd+0x44/0x470
Call Trace:
[c000000005573aa0] [c00000000027bf64] zap_huge_pmd+0x44/0x470 (unreliable)
[c000000005573af0] [c00000000022bbd8] unmap_page_range+0xcf8/0xed0
[c000000005573c30] [c00000000022c2d4] unmap_vmas+0x84/0x120
[c000000005573c80] [c000000000235448] unmap_region+0xd8/0x1b0
[c000000005573d80] [c0000000002378f0] do_munmap+0x2d0/0x4c0
[c000000005573df0] [c000000000237be4] SyS_munmap+0x64/0xb0
[c000000005573e30] [c000000000009560] system_call+0x38/0x108
Instruction dump:
fbe1fff8 fb81ffe0 7c7f1b78 7ca32b78 7cbd2b78 f8010010 7c9a2378 f821ffb1
7cde3378 4bfffea9 7c7b1b79 41820298 <e87f0000> 48000130 7fa5eb78 7fc4f378
Most of the time, the bug is surfacing in a caller up in the stack from
__pSeries_lpar_hugepage_invalidate() which is quite confusing.
This bug is pending since v3.11 but was hidden if a caller of the
caller of __pSeries_lpar_hugepage_invalidate() has pushed the corruped
register (r18 in this case) in the stack and is not using it until
restoring it. GCC 6.2.0 seems to raise it more frequently.
This commit also change the definition of the parameter buffer in
pSeries_lpar_flush_hash_range() to rely on the global define
PLPAR_HCALL9_BUFSIZE (no functional change here).
Fixes: 1a5272866f ("powerpc: Optimize hugepage invalidate")
Cc: stable@vger.kernel.org # v3.11+
Signed-off-by: Laurent Dufour <ldufour@linux.vnet.ibm.com>
Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Acked-by: Balbir Singh <bsingharora@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
hpte_init_lpar() is part of the pseries platform, so name it as such.
Move the fallback implementation for when PSERIES=n into the header,
dropping the weak implementation. The panic() is now handled by the
calling code.
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Moving probe_machine() to after mmu init will cause the ppc_md
fields relative to the hash table management to be overwritten.
Since we have essentially disconnected the machine type from
the hash backend ops, finish the job by moving them to a different
structure.
The only callback that didn't quite fix is update_partition_table
since this is not specific to hash, so I moved it to a standalone
variable for now. We can revisit later if needed.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
[mpe: Fix ppc64e build failure in kexec]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
The various calls to establish exception endianness and AIL are
now done from a single point using already established CPU and FW
feature bits to decide what to do.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Sparse picked up a number of functions that are implemented in C and
then only referred to in asm code.
This introduces asm-prototypes.h, which provides a place for
prototypes of these functions.
This silences some sparse warnings.
Signed-off-by: Daniel Axtens <dja@axtens.net>
[mpe: Add include guards, clean up copyright & GPL text]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
PowerISA 3.0 adds a parition table indexed by LPID. Parition table
allows us to specify the MMU model that will be used for guest and host
translation.
This patch adds support with SLB based hash model (UPRT = 0). What is
required with this model is to support the new hash page table entry
format and also setup partition table such that we use hash table for
address translation.
We don't have segment table support yet.
In order to make sure we don't load KVM module on Power9 (since we don't
have kvm support yet) this patch also disables KVM on Power9.
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
PowerISA 3.0 introduces two pte bits with the below meaning for radix:
00 -> Normal Memory
01 -> Strong Access Order (SAO)
10 -> Non idempotent I/O (Cache inhibited and guarded)
11 -> Tolerant I/O (Cache inhibited)
We drop the existing WIMG bits in the Linux page table in favour of the
above constants. We loose _PAGE_WRITETHRU with this conversion. We only
use writethru via pgprot_cached_wthru() which is used by
fbdev/controlfb.c which is Apple control display and also PPC32.
With respect to _PAGE_COHERENCE, we have been marking hpte always
coherent for some time now. htab_convert_pte_flags() always added
HPTE_R_M.
NOTE: KVM changes need closer review.
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
At the moment the hpte_removebolted callback in ppc_md returns void and
will BUG_ON() if the hpte it's asked to remove doesn't exist in the first
place. This is awkward for the case of cleaning up a mapping which was
partially made before failing.
So, we add a return value to hpte_removebolted, and have it return ENOENT
in the case that the HPTE to remove didn't exist in the first place.
In the (sole) caller, we propagate errors in hpte_removebolted to its
caller to handle. However, we handle ENOENT specially, continuing to
complete the unmapping over the specified range before returning the error
to the caller.
This means that htab_remove_mapping() will work sanely on a partially
present mapping, removing any HPTEs which are present, while also returning
ENOENT to its caller in case it's important there.
There are two callers of htab_remove_mapping():
- In remove_section_mapping() we already WARN_ON() any error return,
which is reasonable - in this case the mapping should be fully
present
- In vmemmap_remove_mapping() we BUG_ON() any error. We change that to
just a WARN_ON() in the case of ENOENT, since failing to remove a
mapping that wasn't there in the first place probably shouldn't be
fatal.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
This will bulk read 4 hash pte slot entries and should reduce the loop
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
We support THP only with book3s_64 and 64K page size. Move
THP details to hash64-64k.h to clarify the same.
Acked-by: Scott Wood <scottwood@freescale.com>
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
In LE kernel, we currently have a hack for kexec that resets the exception
endian before starting a new kernel as the kernel that is loaded could be a
big endian or a little endian kernel. In kdump case, resetting exception
endian fails when one or more cpus is disabled. But we can ignore the failure
and still go ahead, as in most cases crashkernel will be of same endianess
as primary kernel and reseting endianess is not even needed in those cases.
This patch adds a new inline function to say if this is kdump path. This
function is used at places where such a check is needed.
Signed-off-by: Hari Bathini <hbathini@linux.vnet.ibm.com>
[mpe: Rename to kdump_in_progress(), use bool, and edit comment]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
upatepp can get called for a nohpte fault when we find from the linux
page table that the translation was hashed before. In that case
we are sure that there is no existing translation, hence we could
avoid doing tlbie.
We could possibly race with a parallel fault filling the TLB. But
that should be ok because updatepp is only ever relaxing permissions.
We also look at linux pte permission bits when filling hash pte
permission bits. We also hold the linux pte busy bits while
inserting/updating a hashpte entry, hence a paralle update of
linux pte is not possible. On the other hand mprotect involves
ptep_modify_prot_start which cause a hpte invalidate and not updatepp.
Performance number:
We use randbox_access_bench written by Anton.
Kernel with THP disabled and smaller hash page table size.
86.60% random_access_b [kernel.kallsyms] [k] .native_hpte_updatepp
2.10% random_access_b random_access_bench [.] doit
1.99% random_access_b [kernel.kallsyms] [k] .do_raw_spin_lock
1.85% random_access_b [kernel.kallsyms] [k] .native_hpte_insert
1.26% random_access_b [kernel.kallsyms] [k] .native_flush_hash_range
1.18% random_access_b [kernel.kallsyms] [k] .__delay
0.69% random_access_b [kernel.kallsyms] [k] .native_hpte_remove
0.37% random_access_b [kernel.kallsyms] [k] .clear_user_page
0.34% random_access_b [kernel.kallsyms] [k] .__hash_page_64K
0.32% random_access_b [kernel.kallsyms] [k] fast_exception_return
0.30% random_access_b [kernel.kallsyms] [k] .hash_page_mm
With Fix:
27.54% random_access_b random_access_bench [.] doit
22.90% random_access_b [kernel.kallsyms] [k] .native_hpte_insert
5.76% random_access_b [kernel.kallsyms] [k] .native_hpte_remove
5.20% random_access_b [kernel.kallsyms] [k] fast_exception_return
5.12% random_access_b [kernel.kallsyms] [k] .__hash_page_64K
4.80% random_access_b [kernel.kallsyms] [k] .hash_page_mm
3.31% random_access_b [kernel.kallsyms] [k] data_access_common
1.84% random_access_b [kernel.kallsyms] [k] .trace_hardirqs_on_caller
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
If we know that user address space has never executed on other cpus
we could use tlbiel.
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
This still has not been merged and now powerpc is the only arch that does
not have this change. Sorry about missing linuxppc-dev before.
V2->V2
- Fix up to work against 3.18-rc1
__get_cpu_var() is used for multiple purposes in the kernel source. One of
them is address calculation via the form &__get_cpu_var(x). This calculates
the address for the instance of the percpu variable of the current processor
based on an offset.
Other use cases are for storing and retrieving data from the current
processors percpu area. __get_cpu_var() can be used as an lvalue when
writing data or on the right side of an assignment.
__get_cpu_var() is defined as :
__get_cpu_var() always only does an address determination. However, store
and retrieve operations could use a segment prefix (or global register on
other platforms) to avoid the address calculation.
this_cpu_write() and this_cpu_read() can directly take an offset into a
percpu area and use optimized assembly code to read and write per cpu
variables.
This patch converts __get_cpu_var into either an explicit address
calculation using this_cpu_ptr() or into a use of this_cpu operations that
use the offset. Thereby address calculations are avoided and less registers
are used when code is generated.
At the end of the patch set all uses of __get_cpu_var have been removed so
the macro is removed too.
The patch set includes passes over all arches as well. Once these operations
are used throughout then specialized macros can be defined in non -x86
arches as well in order to optimize per cpu access by f.e. using a global
register that may be set to the per cpu base.
Transformations done to __get_cpu_var()
1. Determine the address of the percpu instance of the current processor.
DEFINE_PER_CPU(int, y);
int *x = &__get_cpu_var(y);
Converts to
int *x = this_cpu_ptr(&y);
2. Same as #1 but this time an array structure is involved.
DEFINE_PER_CPU(int, y[20]);
int *x = __get_cpu_var(y);
Converts to
int *x = this_cpu_ptr(y);
3. Retrieve the content of the current processors instance of a per cpu
variable.
DEFINE_PER_CPU(int, y);
int x = __get_cpu_var(y)
Converts to
int x = __this_cpu_read(y);
4. Retrieve the content of a percpu struct
DEFINE_PER_CPU(struct mystruct, y);
struct mystruct x = __get_cpu_var(y);
Converts to
memcpy(&x, this_cpu_ptr(&y), sizeof(x));
5. Assignment to a per cpu variable
DEFINE_PER_CPU(int, y)
__get_cpu_var(y) = x;
Converts to
__this_cpu_write(y, x);
6. Increment/Decrement etc of a per cpu variable
DEFINE_PER_CPU(int, y);
__get_cpu_var(y)++
Converts to
__this_cpu_inc(y)
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
CC: Paul Mackerras <paulus@samba.org>
Signed-off-by: Christoph Lameter <cl@linux.com>
[mpe: Fix build errors caused by set/or_softirq_pending(), and rework
assignment in __set_breakpoint() to use memcpy().]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
CONFIG_JUMP_LABEL doesn't ensure HAVE_JUMP_LABEL, if it
is not the case use maintainers's own mutex to guard
the modification of global values.
Signed-off-by: Zhouyi Zhou <yizhouzhou@ict.ac.cn>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
There were a number of prototypes for functions that no longer
exist. Remove them.
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
The segment identifier and segment size will remain the same in
the loop, So we can compute it outside. We also change the
hugepage_invalidate interface so that we can use it the later patch
CC: <stable@vger.kernel.org>
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
hcall tracepoints add quite a few instructions to our hcall path:
plpar_hcall:
mr r2,r2
mfcr r0
stw r0,8(r1)
b 164 <---- start
ld r12,0(r2)
std r12,32(r1)
cmpdi r12,0
beq 164 <---- end
...
We have an unconditional branch that gets noped out during boot and
a load/compare/branch. We also store the tracepoint value to the
stack for the hcall_exit path to use.
By using jump labels we can simplify this to just a single nop that
gets replaced with a branch when the tracepoint is enabled:
plpar_hcall:
mr r2,r2
mfcr r0
stw r0,8(r1)
nop <----
...
If jump labels are not enabled, we fall back to the old method.
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Even though we have same value for linux PTE bits and hash PTE pits
use the hash pte bits wen updating hash pte
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Acked-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
The only external user of slb_shadow is the pseries lpar code, and it
can access through the paca array instead.
Signed-off-by: Jeremy Kerr <jk@ozlabs.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
On little endian builds call H_SET_MODE so exceptions have the
correct endianness. We need to reset the endian during kexec
so do that in the MMU hashtable clear callback.
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
The spec says it "may be problematic" if CPU x registers the VPA of
CPU y. Add a warning in case we ever do that.
Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
As a part of pseries_idle backend driver cleanup to make
the code common to both pseries and powernv platforms, it
is necessary to move the backend-driver code to drivers/cpuidle.
As a pre-requisite for that, it is essential to move plpar_wrapper.h
to include/asm.
Signed-off-by: Deepthi Dharwar <deepthi@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
