Pull powerpc fixes from Michael Ellerman:
"The main change is we're reverting the initial stack protector support
we merged this cycle. It turns out to not work on toolchains built
with libc support, and fixing it will be need to wait for another
release.
And the rest are all fairly minor:
- Some pasemi machines were not booting due to a missing error check
in prom_find_boot_cpu()
- In EEH we were checking a pointer rather than the bool it pointed
to
- The clang build was broken by a BUILD_BUG_ON() we added.
- The radix (Power9 only) version of map_kernel_page() was broken if
our memory size was a multiple of 2MB, which it generally isn't
Thanks to: Darren Stevens, Gavin Shan, Reza Arbab"
* tag 'powerpc-4.10-3' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux:
powerpc/mm: Use the correct pointer when setting a 2MB pte
powerpc: Fix build failure with clang due to BUILD_BUG_ON()
powerpc: Revert the initial stack protector support
powerpc/eeh: Fix wrong flag passed to eeh_unfreeze_pe()
powerpc: Add missing error check to prom_find_boot_cpu()
The modversion symbol CRCs are emitted as ELF symbols, which allows us
to easily populate the kcrctab sections by relying on the linker to
associate each kcrctab slot with the correct value.
This has a couple of downsides:
- Given that the CRCs are treated as memory addresses, we waste 4 bytes
for each CRC on 64 bit architectures,
- On architectures that support runtime relocation, a R_<arch>_RELATIVE
relocation entry is emitted for each CRC value, which identifies it
as a quantity that requires fixing up based on the actual runtime
load offset of the kernel. This results in corrupted CRCs unless we
explicitly undo the fixup (and this is currently being handled in the
core module code)
- Such runtime relocation entries take up 24 bytes of __init space
each, resulting in a x8 overhead in [uncompressed] kernel size for
CRCs.
Switching to explicit 32 bit values on 64 bit architectures fixes most
of these issues, given that 32 bit values are not treated as quantities
that require fixing up based on the actual runtime load offset. Note
that on some ELF64 architectures [such as PPC64], these 32-bit values
are still emitted as [absolute] runtime relocatable quantities, even if
the value resolves to a build time constant. Since relative relocations
are always resolved at build time, this patch enables MODULE_REL_CRCS on
powerpc when CONFIG_RELOCATABLE=y, which turns the absolute CRC
references into relative references into .rodata where the actual CRC
value is stored.
So redefine all CRC fields and variables as u32, and redefine the
__CRC_SYMBOL() macro for 64 bit builds to emit the CRC reference using
inline assembler (which is necessary since 64-bit C code cannot use
32-bit types to hold memory addresses, even if they are ultimately
resolved using values that do not exceed 0xffffffff). To avoid
potential problems with legacy 32-bit architectures using legacy
toolchains, the equivalent C definition of the kcrctab entry is retained
for 32-bit architectures.
Note that this mostly reverts commit d4703aefdb ("module: handle ppc64
relocating kcrctabs when CONFIG_RELOCATABLE=y")
Acked-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Currently, memory must be hot removed and subsequently re-added in order
to dynamically update the affinity of LMBs specified by a PRRN event.
Earlier implementations of the PRRN event handler ran into issues in which
the hot remove would occur successfully, but a hotplug event would be
initiated from another source and grab the hotplug lock preventing the hot
add from occurring. To prevent this situation, this patch introduces the
notion of a hot "readd" action for memory which atomizes a hot remove and
a hot add into a single, serialized operation on the hotplug queue.
Signed-off-by: John Allen <jallen@linux.vnet.ibm.com>
Reviewed-by: Nathan Fontenot <nfont@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
In __get_user_nosleep, we create an intermediate pointer for the
user address we're about to fetch. We currently don't tag this
pointer as const. Make it const, as we are simply dereferencing
it, and it's scope is limited to the __get_user_nosleep macro.
Signed-off-by: Daniel Axtens <dja@axtens.net>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
In __get_user_nocheck, we create an intermediate pointer for the
user address we're about to fetch. We currently don't tag this
pointer as const. Make it const, as we are simply dereferencing
it, and it's scope is limited to the __get_user_nocheck macro.
Signed-off-by: Daniel Axtens <dja@axtens.net>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
In __get_user_check, we create an intermediate pointer for the
user address we're about to fetch. We currently don't tag this
pointer as const. Make it const, as we are simply dereferencing
it, and it's scope is limited to the __get_user_check macro.
Signed-off-by: Daniel Axtens <dja@axtens.net>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
This adds a not yet working outline of the HPT resizing PAPR
extension. Specifically it adds the necessary ioctl() functions,
their basic steps, the work function which will handle preparation for
the resize, and synchronization between these, the guest page fault
path and guest HPT update path.
The actual guts of the implementation isn't here yet, so for now the
calls will always fail.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
The KVM_PPC_ALLOCATE_HTAB ioctl() is used to set the size of hashed page
table (HPT) that userspace expects a guest VM to have, and is also used to
clear that HPT when necessary (e.g. guest reboot).
At present, once the ioctl() is called for the first time, the HPT size can
never be changed thereafter - it will be cleared but always sized as from
the first call.
With upcoming HPT resize implementation, we're going to need to allow
userspace to resize the HPT at reset (to change it back to the default size
if the guest changed it).
So, we need to allow this ioctl() to change the HPT size.
This patch also updates Documentation/virtual/kvm/api.txt to reflect
the new behaviour. In fact the documentation was already slightly
incorrect since 572abd5 "KVM: PPC: Book3S HV: Don't fall back to
smaller HPT size in allocation ioctl"
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
Currently, kvmppc_alloc_hpt() both allocates a new hashed page table (HPT)
and sets it up as the active page table for a VM. For the upcoming HPT
resize implementation we're going to want to allocate HPTs separately from
activating them.
So, split the allocation itself out into kvmppc_allocate_hpt() and perform
the activation with a new kvmppc_set_hpt() function. Likewise we split
kvmppc_free_hpt(), which just frees the HPT, from kvmppc_release_hpt()
which unsets it as an active HPT, then frees it.
We also move the logic to fall back to smaller HPT sizes if the first try
fails into the single caller which used that behaviour,
kvmppc_hv_setup_htab_rma(). This introduces a slight semantic change, in
that previously if the initial attempt at CMA allocation failed, we would
fall back to attempting smaller sizes with the page allocator. Now, we
try first CMA, then the page allocator at each size. As far as I can tell
this change should be harmless.
To match, we make kvmppc_free_hpt() just free the actual HPT itself. The
call to kvmppc_free_lpid() that was there, we move to the single caller.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
Currently the kvm_hpt_info structure stores the hashed page table's order,
and also the number of HPTEs it contains and a mask for its size. The
last two can be easily derived from the order, so remove them and just
calculate them as necessary with a couple of helper inlines.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Reviewed-by: Thomas Huth <thuth@redhat.com>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
Currently, the powerpc kvm_arch structure contains a number of variables
tracking the state of the guest's hashed page table (HPT) in KVM HV. This
patch gathers them all together into a single kvm_hpt_info substructure.
This makes life more convenient for the upcoming HPT resizing
implementation.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
The difference between kvm_alloc_hpt() and kvmppc_alloc_hpt() is not at
all obvious from the name. In practice kvmppc_alloc_hpt() allocates an HPT
by whatever means, and calls kvm_alloc_hpt() which will attempt to allocate
it with CMA only.
To make this less confusing, rename kvm_alloc_hpt() to kvm_alloc_hpt_cma().
Similarly, kvm_release_hpt() is renamed kvm_free_hpt_cma().
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Reviewed-by: Thomas Huth <thuth@redhat.com>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
This merges in the POWER9 radix MMU host and guest support, which
was put into a topic branch because it touches both powerpc and
KVM code.
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
This adds a few last pieces of the support for radix guests:
* Implement the backends for the KVM_PPC_CONFIGURE_V3_MMU and
KVM_PPC_GET_RMMU_INFO ioctls for radix guests
* On POWER9, allow secondary threads to be on/off-lined while guests
are running.
* Set up LPCR and the partition table entry for radix guests.
* Don't allocate the rmap array in the kvm_memory_slot structure
on radix.
* Don't try to initialize the HPT for radix guests, since they don't
have an HPT.
* Take out the code that prevents the HV KVM module from
initializing on radix hosts.
At this stage, we only support radix guests if the host is running
in radix mode, and only support HPT guests if the host is running in
HPT mode. Thus a guest cannot switch from one mode to the other,
which enables some simplifications.
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
With radix, the guest can do TLB invalidations itself using the tlbie
(global) and tlbiel (local) TLB invalidation instructions. Linux guests
use local TLB invalidations for translations that have only ever been
accessed on one vcpu. However, that doesn't mean that the translations
have only been accessed on one physical cpu (pcpu) since vcpus can move
around from one pcpu to another. Thus a tlbiel might leave behind stale
TLB entries on a pcpu where the vcpu previously ran, and if that task
then moves back to that previous pcpu, it could see those stale TLB
entries and thus access memory incorrectly. The usual symptom of this
is random segfaults in userspace programs in the guest.
To cope with this, we detect when a vcpu is about to start executing on
a thread in a core that is a different core from the last time it
executed. If that is the case, then we mark the core as needing a
TLB flush and then send an interrupt to any thread in the core that is
currently running a vcpu from the same guest. This will get those vcpus
out of the guest, and the first one to re-enter the guest will do the
TLB flush. The reason for interrupting the vcpus executing on the old
core is to cope with the following scenario:
CPU 0 CPU 1 CPU 4
(core 0) (core 0) (core 1)
VCPU 0 runs task X VCPU 1 runs
core 0 TLB gets
entries from task X
VCPU 0 moves to CPU 4
VCPU 0 runs task X
Unmap pages of task X
tlbiel
(still VCPU 1) task X moves to VCPU 1
task X runs
task X sees stale TLB
entries
That is, as soon as the VCPU starts executing on the new core, it
could unmap and tlbiel some page table entries, and then the task
could migrate to one of the VCPUs running on the old core and
potentially see stale TLB entries.
Since the TLB is shared between all the threads in a core, we only
use the bit of kvm->arch.need_tlb_flush corresponding to the first
thread in the core. To ensure that we don't have a window where we
can miss a flush, this moves the clearing of the bit from before the
actual flush to after it. This way, two threads might both do the
flush, but we prevent the situation where one thread can enter the
guest before the flush is finished.
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
This adds code to keep track of dirty pages when requested (that is,
when memslot->dirty_bitmap is non-NULL) for radix guests. We use the
dirty bits in the PTEs in the second-level (partition-scoped) page
tables, together with a bitmap of pages that were dirty when their
PTE was invalidated (e.g., when the page was paged out). This bitmap
is stored in the first half of the memslot->dirty_bitmap area, and
kvm_vm_ioctl_get_dirty_log_hv() now uses the second half for the
bitmap that gets returned to userspace.
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
This adapts our implementations of the MMU notifier callbacks
(unmap_hva, unmap_hva_range, age_hva, test_age_hva, set_spte_hva)
to call radix functions when the guest is using radix. These
implementations are much simpler than for HPT guests because we
have only one PTE to deal with, so we don't need to traverse
rmap chains.
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
This adds the code to construct the second-level ("partition-scoped" in
architecturese) page tables for guests using the radix MMU. Apart from
the PGD level, which is allocated when the guest is created, the rest
of the tree is all constructed in response to hypervisor page faults.
As well as hypervisor page faults for missing pages, we also get faults
for reference/change (RC) bits needing to be set, as well as various
other error conditions. For now, we only set the R or C bit in the
guest page table if the same bit is set in the host PTE for the
backing page.
This code can take advantage of the guest being backed with either
transparent or ordinary 2MB huge pages, and insert 2MB page entries
into the guest page tables. There is no support for 1GB huge pages
yet.
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
This adds code to branch around the parts that radix guests don't
need - clearing and loading the SLB with the guest SLB contents,
saving the guest SLB contents on exit, and restoring the host SLB
contents.
Since the host is now using radix, we need to save and restore the
host value for the PID register.
On hypervisor data/instruction storage interrupts, we don't do the
guest HPT lookup on radix, but just save the guest physical address
for the fault (from the ASDR register) in the vcpu struct.
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
This adds a field in struct kvm_arch and an inline helper to
indicate whether a guest is a radix guest or not, plus a new file
to contain the radix MMU code, which currently contains just a
translate function which knows how to traverse the guest page
tables to translate an address.
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
This adds the implementation of the KVM_PPC_CONFIGURE_V3_MMU ioctl
for HPT guests on POWER9. With this, we can return 1 for the
KVM_CAP_PPC_MMU_HASH_V3 capability.
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
This adds two capabilities and two ioctls to allow userspace to
find out about and configure the POWER9 MMU in a guest. The two
capabilities tell userspace whether KVM can support a guest using
the radix MMU, or using the hashed page table (HPT) MMU with a
process table and segment tables. (Note that the MMUs in the
POWER9 processor cores do not use the process and segment tables
when in HPT mode, but the nest MMU does).
The KVM_PPC_CONFIGURE_V3_MMU ioctl allows userspace to specify
whether a guest will use the radix MMU or the HPT MMU, and to
specify the size and location (in guest space) of the process
table.
The KVM_PPC_GET_RMMU_INFO ioctl gives userspace information about
the radix MMU. It returns a list of supported radix tree geometries
(base page size and number of bits indexed at each level of the
radix tree) and the encoding used to specify the various page
sizes for the TLB invalidate entry instruction.
Initially, both capabilities return 0 and the ioctls return -EINVAL,
until the necessary infrastructure for them to operate correctly
is added.
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
With host and guest both using radix translation, it is feasible
for the host to take interrupts that come from the guest with
relocation on, and that is in fact what the POWER9 hardware will
do when LPCR[AIL] = 3. All such interrupts use HSRR0/1 not SRR0/1
except for system call with LEV=1 (hcall).
Therefore this adds the KVM tests to the _HV variants of the
relocation-on interrupt handlers, and adds the KVM test to the
relocation-on system call entry point.
We also instantiate the relocation-on versions of the hypervisor
data storage and instruction interrupt handlers, since these can
occur with relocation on in radix guests.
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
This adds definitions for bits in the DSISR register which are used
by POWER9 for various translation-related exception conditions, and
for some more bits in the partition table entry that will be needed
by KVM.
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
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>
This fixes the byte index values for some of the option bits in
the "ibm,architectur-vec-5" property. The "platform facilities options"
bits are in byte 17 not byte 14, so the upper 8 bits of their
definitions need to be 0x11 not 0x0E. The "sub processor support" option
is in byte 21 not byte 15.
Note none of these options are actually looked up in
"ibm,architecture-vec-5" at this time, so there is no bug.
When checking whether option bits are set, we should check that
the offset of the byte being checked is less than the vector
length that we got from the hypervisor.
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
64-bit Book3S exception handlers must find the dynamic kernel base
to add to the target address when branching beyond __end_interrupts,
in order to support kernel running at non-0 physical address.
Support this in KVM by branching with CTR, similarly to regular
interrupt handlers. The guest CTR saved in HSTATE_SCRATCH1 and
restored after the branch.
Without this, the host kernel hangs and crashes randomly when it is
running at a non-0 address and a KVM guest is started.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Acked-by: Paul Mackerras <paulus@ozlabs.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Tear down and free the four-level page tables of physical mappings
during memory hotremove.
Borrow the basic structure of remove_pagetable() and friends from the
identically-named x86 functions. Reduce the frequency of tlb flushes and
page_table_lock spinlocks by only doing them in the outermost function.
There was some question as to whether the locking is needed at all.
Leave it for now, but we could consider dropping it.
Memory must be offline to be removed, thus not in use. So there
shouldn't be the sort of concurrent page walking activity here that
might prompt us to use RCU.
Signed-off-by: Reza Arbab <arbab@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Wire up memory hotplug page mapping for radix. Share the mapping
function already used by radix_init_pgtable().
Signed-off-by: Reza Arbab <arbab@linux.vnet.ibm.com>
Acked-by: Balbir Singh <bsingharora@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
The POWER9 chip supports an LPC bus that isn't hanging
off a PCI bus, so let's add support for that, mapping it
to the reserved space at ISA_IO_BASE
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
We'll be adding non-PCI isa bridge support so let's not
have all the definition in pci-bridge.h
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
The power9_idle_stop method currently takes only the requested stop
level as a parameter and picks up the rest of the PSSCR bits from a
hand-coded macro. This is not a very flexible design, especially when
the firmware has the capability to communicate the psscr value and the
mask associated with a particular stop state via device tree.
This patch modifies the power9_idle_stop API to take as parameters the
PSSCR value and the PSSCR mask corresponding to the stop state that
needs to be set. These PSSCR value and mask are respectively obtained
by parsing the "ibm,cpu-idle-state-psscr" and
"ibm,cpu-idle-state-psscr-mask" fields from the device tree.
In addition to this, the patch adds support for handling stop states
for which ESL and EC bits in the PSSCR are zero. As per the
architecture, a wakeup from these stop states resumes execution from
the subsequent instruction as opposed to waking up at the System
Vector.
The older firmware sets only the Requested Level (RL) field in the
psscr and psscr-mask exposed in the device tree. For older firmware
where psscr-mask=0xf, this patch will set the default sane values that
the set for for remaining PSSCR fields (i.e PSLL, MTL, ESL, EC, and
TR). For the new firmware, the patch will validate that the invariants
required by the ISA for the psscr values are maintained by the
firmware.
This skiboot patch that exports fully populated PSSCR values and the
mask for all the stop states can be found here:
https://lists.ozlabs.org/pipermail/skiboot/2016-September/004869.html
[Optimize the number of instructions before entering STOP with
ESL=EC=0, validate the PSSCR values provided by the firimware
maintains the invariants required as per the ISA suggested by Balbir
Singh]
Acked-by: Balbir Singh <bsingharora@gmail.com>
Signed-off-by: Gautham R. Shenoy <ego@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Currently all the low-power idle states are expected to wake up
at reset vector 0x100. Which is why the macro IDLE_STATE_ENTER_SEQ
that puts the CPU to an idle state and never returns.
On ISA v3.0, when the ESL and EC bits in the PSSCR are zero, the CPU
is expected to wake up at the next instruction of the idle
instruction.
This patch adds a new macro named IDLE_STATE_ENTER_SEQ_NORET for the
no-return variant and reuses the name IDLE_STATE_ENTER_SEQ
for a variant that allows resuming operation at the instruction next
to the idle-instruction.
Acked-by: Balbir Singh <bsingharora@gmail.com>
Signed-off-by: Gautham R. Shenoy <ego@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
POWER9 contains an off core mmu called the nest mmu (NMMU). This is
used by other hardware units on the chip to translate virtual
addresses into real addresses. The unit attempting an address
translation provides the majority of the context required for the
translation request except for the base address of the partition table
(ie. the PTCR) which needs to be programmed into the NMMU.
This patch adds a call to OPAL to set the PTCR for the nest mmu in
opal_init().
Signed-off-by: Alistair Popple <alistair@popple.id.au>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
The proto VSID is built using both the MMU context id and effective
segment ID (ESID). We should not have overlapping bits between those.
That could result in us having a VSID collision. With the current code
we missed masking the top bits of the ESID. This implies for kernel
address we ended up using the top 4 bits of the ESID as part of the
proto VSID, which is wrong.
The current code use the top 4 context values (0x7fffc - 0x7ffff) for
the kernel. With those context IDs used for the kernel, we don't run
into VSID collisions because we get the same proto VSID irrespective of
whether we mask the ESID bits or not. eg:
ea = 0xf000000000000000
context = 0x7ffff
w/out masking:
proto_vsid = (0x7ffff << 6 | 0xf000000000000000 >> 40)
= (0x1ffffc0 | 0xf00000)
= 0x1ffffc0
with masking:
proto_vsid = (0x7ffff << 6 | ((0xf000000000000000 >> 40) & 0x3f))
= (0x1ffffc0 | (0xf00000 & 0x3f))
= 0x1ffffc0 | 0)
= 0x1ffffc0
So although there is no bug, the code is still overly subtle, so fix it
to save ourselves pain in future.
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
A subsequent patch to make KVM handlers relocation-safe makes them
unusable from within alt section "else" cases (due to the way fixed
addresses are taken from within fixed section head code).
Stop open-coding the KVM handlers, and add them both as normal. A more
optimal fix may be to allow some level of alternate feature patching in
the exception macros themselves, but for now this will do.
The TRAMP_KVM handlers must be moved to the "virt" fixed section area
(name is arbitrary) in order to be closer to .text and avoid the dreaded
"relocation truncated to fit" error.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Acked-by: Paul Mackerras <paulus@ozlabs.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Change the calling convention to put the trap number together with
CR in two halves of r12, which frees up HSTATE_SCRATCH2 in the HV
handler.
The 64-bit PR handler entry translates the calling convention back
to match the previous call convention (i.e., shared with 32-bit), for
simplicity.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Acked-by: Paul Mackerras <paulus@ozlabs.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
This patch has been reworked since RFC version. In the RFC, this patch
was preceded by a patch clearing MSR RI for all PPC32 at all time at
exception prologs. Now MSR RI clearing is done only when this 8xx perf
events functionality is compiled in, it is therefore limited to 8xx
and merged inside this patch.
Other main changes have been to take into account detailed review from
Peter Zijlstra. The instructions counter has been reworked to behave
as a free running counter like the three other counters.
The 8xx has no PMU, however some events can be emulated by other means.
This patch implements the following events (as reported by 'perf list'):
cpu-cycles OR cycles [Hardware event]
instructions [Hardware event]
dTLB-load-misses [Hardware cache event]
iTLB-load-misses [Hardware cache event]
'cycles' event is implemented using the timebase clock. Timebase clock
corresponds to CPU clock divided by 16, so number of cycles is
approximatly 16 times the number of TB ticks
On the 8xx, TLB misses are handled by software. It is therefore
easy to count all TLB misses each time the TLB miss exception is
called.
'instructions' is calculated by using instruction watchpoint counter.
This patch sets counter A to count instructions at address greater
than 0, hence we count all instructions executed while MSR RI bit is
set. The counter is set to the maximum which is 0xffff. Every 65535
instructions, debug instruction breakpoint exception fires. The
exception handler increments a counter in memory which then
represent the upper part of the instruction counter. We therefore
end up with a 48 bits counter. In order to avoid unnecessary overhead
while no perf event is active, this counter is started when the first
event referring to this counter is added, and the counter is stopped
when the last event referring to it is deleted. In order to properly
support breakpoint exceptions, MSR RI bit has to be unset in exception
epilogs in order to avoid breakpoint exceptions during critical
sections during changes to SRR0 and SRR1 would be problematic.
All counters are handled as free running counters.
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Scott Wood <oss@buserror.net>
FIX_SRR1() is defined as blank. Last useful instance of FIX_SRR1()
was removed by commit 40ef8cbc6d ("powerpc: Get 64-bit configs to
compile with ARCH=powerpc") in 2005.
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Scott Wood <oss@buserror.net>
This patch implements P(Presented)/Q(Queued) states for ICS irqs.
When the interrupt is presented, set P. Present if P was not set.
If P is already set, don't present again, set Q.
When the interrupt is EOI'ed, move Q into P (and clear Q). If it is
set, re-present.
The asserted flag used by LSI is also incorporated into the P bit.
When the irq state is saved, P/Q bits are also saved, they need some
qemu modifications to be recognized and passed around to be restored.
KVM_XICS_PENDING bit set and saved should also indicate
KVM_XICS_PRESENTED bit set and saved. But it is possible some old
code doesn't have/recognize the P bit, so when we restore, we set P
for PENDING bit, too.
The idea and much of the code come from Ben.
Signed-off-by: Li Zhong <zhong@linux.vnet.ibm.com>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
This patch implements HW breakpoint on the 8xx. The 8xx has
capability to manage HW breakpoints, which is slightly different
than BOOK3S:
1/ The breakpoint match doesn't trigger a DSI exception but a
dedicated data breakpoint exception.
2/ The breakpoint happens after the instruction has completed,
no need to single step or emulate the instruction,
3/ Matched address is not set in DAR but in BAR,
4/ DABR register doesn't exist, instead we have registers
LCTRL1, LCTRL2 and CMPx registers,
5/ The match on one comparator is not on a double word but
on a single word.
The patch does:
1/ Prepare the dedicated registers in call to __set_dabr(). In order
to emulate the double word handling of BOOK3S, comparator E is set to
DABR address value and comparator F to address + 4. Then breakpoint 1
is set to match comparator E or F,
2/ Skip the singlestepping stage when compiled for CONFIG_PPC_8xx,
3/ Implement the exception. In that exception, the matched address
is taken from SPRN_BAR and manage as if it was from SPRN_DAR.
4/ I/D TLB error exception routines perform a tlbie on bad TLBs. That
tlbie triggers the breakpoint exception when performed on the
breakpoint address. For this reason, the routine returns if the match
is from one of those two tlbie.
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Scott Wood <oss@buserror.net>
BOOK3S also has DABR register and capability to handle data
breakpoints, so this patch enable it on all BOOK3S, not only 64 bits.
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Scott Wood <oss@buserror.net>
Anton says: In commit 4db7327194 ("powerpc: Add option to use jump
label for cpu_has_feature()") and commit c12e6f24d4 ("powerpc: Add
option to use jump label for mmu_has_feature()") we added:
BUILD_BUG_ON(!__builtin_constant_p(feature))
to cpu_has_feature() and mmu_has_feature() in order to catch usage
issues (such as cpu_has_feature(cpu_has_feature(X), which has happened
once in the past). Unfortunately LLVM isn't smart enough to resolve
this, and it errors out.
I work around it in my clang/LLVM builds of the kernel, but I have just
discovered that it causes a lot of issues for the bcc (eBPF) trace tool
(which uses LLVM).
For now just #ifdef it away for clang builds.
Fixes: 4db7327194 ("powerpc: Add option to use jump label for cpu_has_feature()")
Fixes: c12e6f24d4 ("powerpc: Add option to use jump label for mmu_has_feature()")
Cc: stable@vger.kernel.org # v4.8+
Reported-by: Anton Blanchard <anton@samba.org>
Tested-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
In commit a4b349540a ("powerpc/mm: Cleanup LPCR defines") we updated
LPCR_VRMASD wrongly as below.
-#define LPCR_VRMASD (0x1ful << (63-16))
+#define LPCR_VRMASD_SH 47
+#define LPCR_VRMASD (ASM_CONST(1) << LPCR_VRMASD_SH)
We initialize the VRMA bits in LPCR to 0x00 in kvm. Hence using a
different mask value as above while updating lpcr should not have any
impact.
This patch updates it to the correct value.
Fixes: a4b349540a ("powerpc/mm: Cleanup LPCR defines")
Reported-by: Ram Pai <linuxram@us.ibm.com>
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Jia He <hejianet@gmail.com>
Acked-by: Paul Mackerras <paulus@ozlabs.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Currently we have optimized hand-coded assembly checksum routines for
big-endian 64-bit systems, but for little-endian we use the generic C
routines. This modifies the optimized routines to work for
little-endian. With this, we no longer need to enable
CONFIG_GENERIC_CSUM. This also fixes a couple of comments in
checksum_64.S so they accurately reflect what the associated instruction
does.
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
[mpe: Use the more common __BIG_ENDIAN__]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
These functions compute an IP checksum by computing a 64-bit sum and
folding it to 32 bits (the "nofold" in their names refers to folding
down to 16 bits). However, doing (u32) (s + (s >> 32)) is not
sufficient to fold a 64-bit sum to 32 bits correctly. The addition
can produce a carry out from bit 31, which needs to be added in to
the sum to produce the correct result.
To fix this, we copy the from64to32() function from lib/checksum.c
and use that.
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
