On the PCI plugging event, PCI slot's subordinate devices are
scanned and their (IO and MMIO) resources are assigned. Platform
dependent resources (PE#, IO/MMIO/DMA windows) are allocated or
created on updating windows of the slot's upstream bridge.
This updates the windows of the hot plugged slot's upstream bridge
in pcibios_finish_adding_to_bus() so that the platform resources
(PE#, IO/MMIO/DMA segments) are allocated or created accordingly.
Signed-off-by: Gavin Shan <gwshan@linux.vnet.ibm.com>
Reviewed-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
This supports releasing PEs dynamically. A reference count is
introduced to PE representing number of PCI devices associated
with the PE. The reference count is increased when PCI device
joins the PE and decreased when PCI device leaves the PE in
pnv_pci_release_device(). When the count becomes zero, the PE
and its consumed resources are released. Note that the count
is accessed concurrently. So a counter with "int" type is enough
here.
In order to release the sources consumed by the PE, couple of
helper functions are introduced as below:
* pnv_pci_ioda1_unset_window() - Unset IODA1 DMA32 window
* pnv_pci_ioda1_release_dma_pe() - Release IODA1 DMA32 segments
* pnv_pci_ioda2_release_dma_pe() - Release IODA2 DMA resource
* pnv_ioda_release_pe_seg() - Unmap IO/M32/M64 segments
Signed-off-by: Gavin Shan <gwshan@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
pnv_ioda_deconfigure_pe() is visible only when CONFIG_PCI_IOV is
enabled. The function will be used to tear down PE's associated
mapping in PCI hotplug path that doesn't depend on CONFIG_PCI_IOV.
This makes pnv_ioda_deconfigure_pe() visible and not depend on
CONFIG_PCI_IOV.
Signed-off-by: Gavin Shan <gwshan@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
The PCI slots are associated with root port or downstream ports
of the PCIe switch connected to root port. When adapter is hot
added to the PCI slot, it usually requests more IO or memory
resource from the directly connected parent bridge (port) and
update the bridge's windows accordingly. The resource windows
of upstream bridges can't be updated automatically. It possibly
leads to unbalanced resource across the bridges: The window of
downstream bridge is overruning that of upstream bridge. The
IO or MMIO path won't work.
This resolves the above issue by extending bridge windows of
root port and upstream port of the PCIe switch connected to
the root port to PHB's windows.
The windows of root port and bridge behind that are extended to
the PHB's windows to accomodate the PCI hotplug happening in
future. The PHB's 64KB 32-bits MSI region is included in bridge's
M32 windows (in hardware) though it's excluded in the corresponding
resource, as the bridge's M32 windows have 1MB as their minimal
alignment. We observed EEH error during system boot when the MSI
region is included in bridge's M32 window.
This excludes top 1MB (including 64KB 32-bits MSI region) region
from bridge's M32 windows when extending them.
Signed-off-by: Gavin Shan <gwshan@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
There is no parent bridge for root bus, meaning pcibios_setup_bridge()
isn't invoked for root bus. The PE for root bus is the ancestor of
other PEs in PELTV. It means we need PE for root bus populated before
all others.
This populates the PE for root bus in pcibios_setup_bridge() path
if it's not populated yet. The PE number next to the reserved one
is used as the PE# to avoid holes in continuous M64 space.
Signed-off-by: Gavin Shan <gwshan@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Currently, the PEs and their associated resources are assigned in
ppc_md.pcibios_fixup() except those used by SRIOV VFs. The function
is called for once after PCI probing and resources assignment is
completed. So it's obviously not hotplug friendly.
This creates PEs dynamically in pcibios_setup_bridge() that is
called for the event during system bootup and PCI hotplug: updating
PCI bridge's windows after resource assignment/reassignment are done.
In partial hotplug case, not all PCI devices included to one particular
PE are unplugged and plugged again, we just need unbinding/binding the
hot added PCI devices with the corresponding PE without creating new
one. The change is applied to IODA1 and IODA2 PHBs only. The behaviour
on NPU PHBs aren't changed. There are no PCI bridges on NPU PHBs,
meaning pcibios_setup_bridge() won't be invoked there. We have to use
old path (pnv_pci_ioda_fixup()) to setup PEs on NPU PHBs.
Signed-off-by: Gavin Shan <gwshan@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
PE number for one particular PE can be allocated dynamically or
reserved according to the consumed M64 (64-bits prefetchable)
segments of the PE. The M64 segment can't be remapped to arbitrary
PE, meaning the PE number is determined according to the index
of the consumed M64 segment. As below figure shows, M64 resource
grows from low to high end, meaning the PE (number) reserved
according to M64 segment grows from low to high end as well,
so does the dynamically allocated PE number. It will lead to
conflict: PE number (M64 segment) reserved by dynamic allocation
is required by hot added PCI adapter at later point. It fails
the PCI hotplug because of the PE number can't be reserved
based on the index of the consumed M64 segment.
+---+---+---+---+---+--------------------------------+-----+
| 0 | 1 | 2 | 3 | 4 | ....... | 255 |
+---+---+---+---+---+--------------------------------+-----+
PE number for dynamic allocation ----------------->
PE number reserved for M64 segment ----------------->
To resolve above conflicts, this forces the PE number to be
allocated dynamically in reverse order. With this patch applied,
the PE numbers are reserved in ascending order, but allocated
dynamically in reverse order.
Signed-off-by: Gavin Shan <gwshan@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Each PHB maintains an array helping to translate 2-bytes Request
ID (RID) to PE# with the assumption that PE# takes one byte, meaning
that we can't have more than 256 PEs. However, pci_dn->pe_number
already had 4-bytes for the PE#.
This extends the PE# capacity for every PHB. After that, the PE number
is represented by 4-bytes value. Then we can reuse IODA_INVALID_PE to
check the PE# in phb->pe_rmap[] is valid or not.
Signed-off-by: Gavin Shan <gwshan@linux.vnet.ibm.com>
Reviewed-by: Daniel Axtens <dja@axtens.net>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
pnv_pci_ioda_setup_opal_tce_kill() called by pnv_ioda_setup_dma()
to remap the TCE kill regiter. What's done in pnv_ioda_setup_dma()
will be covered in pcibios_setup_bridge() which is invoked on each
PCI bridge. It means we will possibly remap the TCE kill register
for multiple times and it's unnecessary.
This moves pnv_pci_ioda_setup_opal_tce_kill() to where the PHB is
initialized (pnv_pci_init_ioda_phb()) to avoid above issue.
Signed-off-by: Gavin Shan <gwshan@linux.vnet.ibm.com>
Reviewed-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
The macro defined in arch/powerpc/platforms/powernv/pci.c isn't
used by anyone. Just remove it.
Signed-off-by: Gavin Shan <gwshan@linux.vnet.ibm.com>
Reviewed-by: Andrew Donnellan <andrew.donnellan@au1.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
This overrides pcibios_setup_bridge() that is called to update PCI
bridge windows when PCI resource assignment is completed, to assign
PE and setup various (resource) mapping for the PE in subsequent
patches.
Signed-off-by: Gavin Shan <gwshan@linux.vnet.ibm.com>
Reviewed-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Export cpu_to_core_id(). This will be used by the lpfc driver.
This enables topology_core_id() from <linux/topology.h> (defined
to cpu_to_core_id() in arch/powerpc/include/asm/topology.h) to be
used by (non-builtin) modules.
That is arch-neutral, already used by eg, drivers/base/topology.c,
but it is builtin (obj-y in Makefile) thus didn't need the export.
Since the module uses topology_core_id() and this is defined to
cpu_to_core_id(), it needs the export, otherwise:
ERROR: "cpu_to_core_id" [drivers/scsi/lpfc/lpfc.ko] undefined!
Tested on next-20160601.
Signed-off-by: Mauricio Faria de Oliveira <mauricfo@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
This enables new registers, LMRR and LMSER, that can trigger an EBB in
userspace code when a monitored load (via the new ldmx instruction)
loads memory from a monitored space. This facility is controlled by a
new FSCR bit, LM.
This patch disables the FSCR LM control bit on task init and enables
that bit when a load monitor facility unavailable exception is taken
for using it. On context switch, this bit is then used to determine
whether the two relevant registers are saved and restored. This is
done lazily for performance reasons.
Signed-off-by: Jack Miller <jack@codezen.org>
Signed-off-by: Michael Neuling <mikey@neuling.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
This fixes a few issues with FSCR init and switching.
In commit 152d523e63 ("powerpc: Create context switch helpers
save_sprs() and restore_sprs()") we moved the setting of the FSCR
register from inside an CPU_FTR_ARCH_207S section to inside just a
CPU_FTR_ARCH_DSCR section. Hence we are setting FSCR on POWER6/7 where
the FSCR doesn't exist. This is harmless but we shouldn't do it.
Also, we can simplify the FSCR context switch. We don't need to go
through the calculation involving dscr_inherit. We can just restore
what we saved last time.
We also set an initial value in INIT_THREAD, so that pid 1 which is
cloned from that gets a sane value.
Based on patch by Jack Miller.
Signed-off-by: Michael Neuling <mikey@neuling.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Current comment in the early_setup_secondary() for paca->soft_enabled
update is misleading. Comment should say to Mark interrupts "disabled"
instead of "enabled". Fix the typo.
Signed-off-by: Madhavan Srinivasan <maddy@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Fixes the following testsuite failure:
$ sudo ./perf test -v kallsyms
1: vmlinux symtab matches kallsyms :
--- start ---
test child forked, pid 12489
Using /proc/kcore for kernel object code
Looking at the vmlinux_path (8 entries long)
Using /boot/vmlinux for symbols
0xc00000000003d300: diff name v: .kretprobe_trampoline_holder k: kretprobe_trampoline
Maps only in vmlinux:
c00000000086ca38-c000000000879b6c 87ca38 [kernel].text.unlikely
c000000000879b6c-c000000000bf0000 889b6c [kernel].meminit.text
c000000000bf0000-c000000000c53264 c00000 [kernel].init.text
c000000000c53264-d000000004250000 c63264 [kernel].exit.text
d000000004250000-d000000004450000 0 [libcrc32c]
d000000004450000-d000000004620000 0 [xfs]
d000000004620000-d000000004680000 0 [autofs4]
d000000004680000-d0000000046e0000 0 [x_tables]
d0000000046e0000-d000000004780000 0 [ip_tables]
d000000004780000-d0000000047e0000 0 [rng_core]
d0000000047e0000-ffffffffffffffff 0 [pseries_rng]
Maps in vmlinux with a different name in kallsyms:
Maps only in kallsyms:
d000000000000000-f000000000000000 1000000000010000 [kernel.kallsyms]
f000000000000000-ffffffffffffffff 3000000000010000 [kernel.kallsyms]
test child finished with -1
---- end ----
vmlinux symtab matches kallsyms: FAILED!
The problem is that the kretprobe_trampoline symbol looks like this:
$ eu-readelf -s /boot/vmlinux G kretprobe_trampoline
2431: c000000001302368 24 NOTYPE LOCAL DEFAULT 37 kretprobe_trampoline_holder
2432: c00000000003d300 8 FUNC LOCAL DEFAULT 1 .kretprobe_trampoline_holder
97543: c00000000003d300 0 NOTYPE GLOBAL DEFAULT 1 kretprobe_trampoline
Its type is NOTYPE, and its size is 0, and this is a problem because
symbol-elf.c:dso__load_sym skips function symbols that are not STT_FUNC
or STT_GNU_IFUNC (this is determined by elf_sym__is_function). Even
if the type is changed to STT_FUNC, when dso__load_sym calls
symbols__fixup_duplicate, the kretprobe_trampoline symbol is dropped in
favour of .kretprobe_trampoline_holder because the latter has non-zero
size (as determined by choose_best_symbol).
With this patch, all vmlinux symbols match /proc/kallsyms and the
testcase passes.
Commit c1c355ce14 ("x86/kprobes: Get rid of
kretprobe_trampoline_holder()") gets rid of kretprobe_trampoline_holder
altogether on x86. This commit does the same on powerpc. This change
introduces no regressions on the perf and ftracetest testsuite results.
Reviewed-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Signed-off-by: Thiago Jung Bauermann <bauerman@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
On Book3E CPUs (and possibly other configs), it is possible to have SRIOV
(CONFIG_PCI_IOV) set without CONFIG_EEH. The SRIOV code does not check
for this, and if EEH is disabled, pci_dn.c fails to build.
Fix this by gating the EEH-specific code in the SRIOV implementation
behind CONFIG_EEH.
Fixes: 39218cd0 ("powerpc/eeh: EEH device for VF")
Reported-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Russell Currey <ruscur@russell.cc>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
This adds support for using CAPP DMA mode, which is required for XSL
based cards such as the Mellanox CX4 to function.
This is currently an RFC as it depends on the corresponding support to
be merged into skiboot first, which was submitted here:
http://patchwork.ozlabs.org/patch/625582/
In the event that the skiboot on the system does not have the above
support, it will indicate as such in the kernel log and abort the init
process.
Signed-off-by: Ian Munsie <imunsie@au1.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Sparse complains that it doesn't know what REG_BYTE is:
arch/powerpc/kernel/align.c:313:29: error: undefined identifier 'REG_BYTE'
REG_BYTE is defined differently based on whether we're compiling for
LE, BE32 or BE64. Sparse apparently doesn't provide __BIG_ENDIAN__ or
__LITTLE_ENDIAN__, which means we get no definition.
Rather than check for __BIG_ENDIAN__ and then separately for
__LITTLE_ENDIAN__, just switch the #ifdef to check for __BIG_ENDIAN__
and then #else we define the little endian version. Technically that's
dicey because PDP_ENDIAN is also a possibility, but we already do it in
a lot of places so one more hardly matters.
Signed-off-by: Daniel Axtens <dja@axtens.net>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Sometimes headers that provide prototypes for functions are
accidentally omitted from the files that define the functions.
Fix a couple of times that occurs.
Signed-off-by: Daniel Axtens <dja@axtens.net>
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>
This is just a smattering of things picked up by sparse that should
be made static.
Signed-off-by: Daniel Axtens <dja@axtens.net>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
The array crash_shutdown_handles is an array of size CRASH_HANDLER_MAX+1
containing up to CRASH_HANDLER_MAX shutdown_handlers. It is assumed to
be NULL terminated, which it is under normal circumstances. Array
accesses in the functions crash_shutdown_unregister() and
default_machine_crash_shutdown() rely on this NULL termination property
when traversing this list and don't protect again out of bounds accesses.
If the NULL terminator were somehow overwritten these functions could
potentially access out of the bounds of the array.
Shrink the array to size CRASH_HANDLER_MAX and implement explicit array
bounds checking when accessing the elements of the
crash_shutdown_handles[] array in crash_shutdown_unregister() and
default_machine_crash_shutdown().
Signed-off-by: Suraj Jitindar Singh <sjitindarsingh@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
The mm zone mechanism was traditionally used by arch specific code to
partition memory into allocation zones. However there are several zones
that are managed by the mm subsystem rather than the architecture. Most
architectures set the max PFN of these special zones to zero, however on
powerpc we set them to ~0ul. This, in conjunction with a bug in
free_area_init_nodes() results in all of system memory being placed in
ZONE_DEVICE when enabled. Device memory cannot be used for regular kernel
memory allocations so this will cause a kernel panic at boot. Given the
planned addition of more mm managed zones (ZONE_CMA) we should aim to be
consistent with every other architecture and set the max PFN for these
zones to zero.
Signed-off-by: Oliver O'Halloran <oohall@gmail.com>
Reviewed-by: Balbir Singh <bsingharora@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
THREAD_DSCR:
Added in efcac6589a "powerpc: Per process DSCR + some fixes (try#4)"
Last usage removed in 152d523e63 "powerpc: Create context switch helpers save_sprs() and restore_sprs()"
THREAD_DSCR_INHERIT:
Added in 714332858b "powerpc: Restore correct DSCR in context switch"
Last usage removed in 152d523e63 "powerpc: Create context switch helpers save_sprs() and restore_sprs()"
THREAD_TAR:
Added in 2468dcf641 "powerpc: Add support for context switching the TAR register"
Last usage removed in 152d523e63 "powerpc: Create context switch helpers save_sprs() and restore_sprs()"
THREAD_BESCR, THREAD_EBBHR and THREAD_EBBRR:
Added in 9353374b8e "powerpc: Context switch the new EBB SPRs"
Last usage removed in 152d523e63 "powerpc: Create context switch helpers save_sprs() and restore_sprs()"
THREAD_SIAR, THREAD_SDAR, THREAD_SIER, THREAD_MMCR0, and THREAD_MMCR2:
Added in 59affcd3e4 "powerpc: Context switch more PMU related SPRs"
Last usage removed in b11ae95100 "powerpc: Partial revert of "Context switch more PMU related SPRs""
PACA_LOCK_TOKEN:
Added in 9e368f2915 "KVM: PPC: book3s_hv: Add support for PPC970-family processors"
Last usage removed in c17b98cf60 "KVM: PPC: Book3S HV: Remove code for PPC970 processors"
HCALL_STAT_SIZE, HCALL_STAT_CALLS, HCALL_STAT_TB and HCALL_STAT_PURR:
Added in 57852a853b "[POWERPC] powerpc: Instrument Hypervisor Calls"
Last usage removed in c8cd093a6e "powerpc: tracing: Add hypervisor call tracepoints"
VCPU_EPLC:
Added in d30f6e4800 "KVM: PPC: booke: category E.HV (GS-mode) support"
Never used.
CPU_DOWN_FLUSH:
Added in e7affb1dba "powerpc/cache: add cache flush operation for various e500"
Never used.
CFG_STAMP_XSEC:
Added in 14cf11af6c "powerpc: Merge enough to start building in arch/powerpc."
Last usage removed in 0e469db8f7 "powerpc: Rework VDSO gettimeofday to prevent time going backwards"
KVM_LPCR:
Added in aa04b4cc5b "KVM: PPC: Allocate RMAs (Real Mode Areas) at boot for use by guests"
Last usage removed in a0144e2a6b "KVM: PPC: Book3S HV: Store LPCR value for each virtual core"
GPR15, GPR16, GPR17, GPR18, GPR19, GPR20, GPR21, GPR22, GPR23, GPR24,
GPR25, GPR26, GPR27, GPR28, GPR29, GPR30 and GPR31:
Added in 14cf11af6c "powerpc: Merge enough to start building in arch/powerpc."
Never used.
VCPU_SHADOW_FSCR:
Added in 616dff8602 "KVM: PPC: Book3S PR: Handle Facility interrupt and FSCR"
Never used.
VCPU_SHADOW_SRR1:
Added in a2d56020d1 "KVM: PPC: Book3S PR: Keep volatile reg values in vcpu rather than shadow_vcpu"
Never used.
KVM_SPLIT_SIZE:
Added in b4deba5c41 "KVM: PPC: Book3S HV: Implement dynamicmicro-threading on POWER8"
Never used.
VCPU_VCPUID:
Added in de56a948b9 "KVM: PPC: Add support for Book3S processors in hypervisor mode"
Last usage removed 1b400ba0cd "KVM: PPC: Book3S HV: Improve handling of local vs. global TLB invalidations"
_MQ:
Added in 14cf11af6c "powerpc: Merge enough to start building in arch/powerpc."
Never used.
AUDITCONTEXT:
Added in 14cf11af6c "powerpc: Merge enough to start building in arch/powerpc."
Last usage removed in 401d1f029b "[PATCH] syscall entry/exit revamp"
CLONE_VM:
Added in 14cf11af6c "powerpc: Merge enough to start building in arch/powerpc."
Currently unused.
CLONE_UNTRACED:
Added in 14cf11af6c "powerpc: Merge enough to start building in arch/powerpc."
Currently unused.
Signed-off-by: Rashmica Gupta <rashmicy@gmail.com>
[mpe: Munge change log]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
memory_hotplug_max() uses hot_add_drconf_memory_max() to get maxmimum
addressable memory by referring to ibm,dyanamic-memory property. There
are three problems with the current approach:
1 hot_add_drconf_memory_max() assumes that ibm,dynamic-memory includes
all the LMBs of the guest, but that is not true for PowerKVM which
populates only DR LMBs (LMBs that can be hotplugged/removed) in that
property.
2 hot_add_drconf_memory_max() multiplies lmb-size with lmb-count to arrive
at the max possible address. Since ibm,dynamic-memory doesn't include
RMA LMBs, the address thus obtained will be less than the actual max
address. For example, if max possible memory size is 32G, with lmb-size
of 256MB there can be 127 LMBs in ibm,dynamic-memory (1 LMB for RMA
which won't be present here). hot_add_drconf_memory_max() would then
return the max addressable memory as 127 * 256MB = 31.75GB, the max
address should have been 32G which is what ibm,lrdr-capacity shows.
3 In PowerKVM, there can be a gap between the end of boot time RAM and
beginning of hotplug RAM area. So just multiplying lmb-count with
lmb-size will not provide the correct max possible address for PowerKVM.
This patch fixes 1 by using ibm,lrdr-capacity property to return the max
addressable memory whenever the property is present. Then it fixes 2 & 3
by fetching the address of the last LMB in ibm,dynamic-memory property.
Fixes: cd34206e94 ("powerpc: Add memory_hotplug_max()")
Signed-off-by: Bharata B Rao <bharata@linux.vnet.ibm.com>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Bharata B Rao <bharata@linux.vnet.ibm.com>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
There is an ordering issue with spin_unlock_wait() on powerpc, because
the spin_lock primitive is an ACQUIRE and an ACQUIRE is only ordering
the load part of the operation with memory operations following it.
Therefore the following event sequence can happen:
CPU 1 CPU 2 CPU 3
================== ==================== ==============
spin_unlock(&lock);
spin_lock(&lock):
r1 = *lock; // r1 == 0;
o = object; o = READ_ONCE(object); // reordered here
object = NULL;
smp_mb();
spin_unlock_wait(&lock);
*lock = 1;
smp_mb();
o->dead = true; < o = READ_ONCE(object); > // reordered upwards
if (o) // true
BUG_ON(o->dead); // true!!
To fix this, we add a "nop" ll/sc loop in arch_spin_unlock_wait() on
ppc, the "nop" ll/sc loop reads the lock
value and writes it back atomically, in this way it will synchronize the
view of the lock on CPU1 with that on CPU2. Therefore in the scenario
above, either CPU2 will fail to get the lock at first or CPU1 will see
the lock acquired by CPU2, both cases will eliminate this bug. This is a
similar idea as what Will Deacon did for ARM64 in:
d86b8da04d ("arm64: spinlock: serialise spin_unlock_wait against concurrent lockers")
Furthermore, if the "nop" ll/sc figures out the lock is locked, we
actually don't need to do the "nop" ll/sc trick again, we can just do a
normal load+check loop for the lock to be released, because in that
case, spin_unlock_wait() is called when someone is holding the lock, and
the store part of the "nop" ll/sc happens before the lock release of the
current lock holder:
"nop" ll/sc -> spin_unlock()
and the lock release happens before the next lock acquisition:
spin_unlock() -> spin_lock() <next holder>
which means the "nop" ll/sc happens before the next lock acquisition:
"nop" ll/sc -> spin_unlock() -> spin_lock() <next holder>
With a smp_mb() preceding spin_unlock_wait(), the store of object is
guaranteed to be observed by the next lock holder:
STORE -> smp_mb() -> "nop" ll/sc
-> spin_unlock() -> spin_lock() <next holder>
This patch therefore fixes the issue and also cleans the
arch_spin_unlock_wait() a little bit by removing superfluous memory
barriers in loops and consolidating the implementations for PPC32 and
PPC64 into one.
Suggested-by: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Signed-off-by: Boqun Feng <boqun.feng@gmail.com>
Reviewed-by: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
[mpe: Inline the "nop" ll/sc loop and set EH=0, munge change log]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Since the pstore code has moved away from nvram.c, remove unused
pstore headers pstore.h and kmsg_dump.h.
Signed-off-by: Geliang Tang <geliangtang@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
We're approaching 20 locations where we need to check for ELF ABI v2.
That's fine, except the logic is a bit awkward, because we have to check
that _CALL_ELF is defined and then what its value is.
So check it once in asm/types.h and define PPC64_ELF_ABI_v2 when ELF ABI
v2 is detected.
We also have a few places where what we're really trying to check is
that we are using the 64-bit v1 ABI, ie. function descriptors. So also
add a #define for that, which simplifies several checks.
Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
MPIC was only used by Power3 which is now unsupported, so remove MPIC
code. XICS is now the only supported interrupt controller for
pSeries so do some cleanups too.
Signed-off-by: Rashmica Gupta <rashmicy@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
MPIC was only used by Power3 which is now unsupported, so remove MPIC
code.
Signed-off-by: Rashmica Gupta <rashmicy@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
MPIC was only used by Power3 which is now unsupported, so remove MPIC
code. XICS is now the only supported interrupt controller for
pSeries so do some cleanups too.
Signed-off-by: Rashmica Gupta <rashmicy@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
MPIC was only used by Power3 which is now unsupported, so remove MPIC
code. XICS is now the only supported interrupt controller for
pSeries so do some cleanups too.
Signed-off-by: Rashmica Gupta <rashmicy@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
MPIC was only used by Power3 which is now unsupported, so drop support
for MPIC. XICS is now the only supported interrupt controller for
pSeries so make the XICS functions generic.
Signed-off-by: Rashmica Gupta <rashmicy@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
sub_reloc_offset() has not been used since commit
917f0af9e5 ("powerpc: Remove arch/ppc and include/asm-ppc") which
removed include/asm-ppc/prom.h.
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Align the hot loops in our assembly implementation of strncpy(),
strncmp() and memchr().
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
A number of our assembly implementations of string functions do not
align their hot loops. I was going to align them manually, but I
realised that they are are almost instruction for instruction
identical to what gcc produces, with the advantage that gcc does
align them.
In light of that, let's just remove the assembly versions.
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
In setup_sigcontext(), we set current->thread.vrsave then use it
straight after. Since current is hidden from the compiler via inline
assembly, it cannot optimise this and we end up with a load hit store.
Fix this by using a temporary.
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
In both __giveup_fpu() and __giveup_altivec() we make two modifications
to tsk->thread.regs->msr. gcc decides to do a read/modify/write of
each change, so we end up with a load hit store:
ld r9,264(r10)
rldicl r9,r9,50,1
rotldi r9,r9,14
std r9,264(r10)
...
ld r9,264(r10)
rldicl r9,r9,40,1
rotldi r9,r9,24
std r9,264(r10)
Fix this by using a temporary.
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
- ptrace: Fix out of bounds array access warning from Khem Raj
- pseries: Fix PCI config address for DDW from Gavin Shan
- pseries: Fix IBM_ARCH_VEC_NRCORES_OFFSET since POWER8NVL was added from Michael Ellerman
- of: fix autoloading due to broken modalias with no 'compatible' from Wolfram Sang
- radix: Fix always false comparison against MMU_NO_CONTEXT from Aneesh Kumar K.V
- hash: Compute the segment size correctly for ISA 3.0 from Aneesh Kumar K.V
- nohash: Fix build break with 64K pages from Michael Ellerman
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Merge tag 'powerpc-4.7-3Michael Ellerman:' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux
Pull powerpc fixes from
- ptrace: Fix out of bounds array access warning from Khem Raj
- pseries: Fix PCI config address for DDW from Gavin Shan
- pseries: Fix IBM_ARCH_VEC_NRCORES_OFFSET since POWER8NVL was added
from Michael Ellerman
- of: fix autoloading due to broken modalias with no 'compatible' from
Wolfram Sang
- radix: Fix always false comparison against MMU_NO_CONTEXT from Aneesh
Kumar K.V
- hash: Compute the segment size correctly for ISA 3.0 from Aneesh
Kumar K.V
- nohash: Fix build break with 64K pages from Michael Ellerman
* tag 'powerpc-4.7-3' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux:
powerpc/nohash: Fix build break with 64K pages
powerpc/mm/hash: Compute the segment size correctly for ISA 3.0
powerpc/mm/radix: Fix always false comparison against MMU_NO_CONTEXT
of: fix autoloading due to broken modalias with no 'compatible'
powerpc/pseries: Fix IBM_ARCH_VEC_NRCORES_OFFSET since POWER8NVL was added
powerpc/pseries: Fix PCI config address for DDW
powerpc/ptrace: Fix out of bounds array access warning
Commit 74701d5947 "powerpc/mm: Rename function to indicate we are
allocating fragments" renamed page_table_free() to pte_fragment_free().
One occurrence was mistyped as pte_fragment_fre().
This only breaks the nohash 64K page build, which is not the default or
enabled in any defconfig.
Fixes: 74701d5947 ("powerpc/mm: Rename function to indicate we are allocating fragments")
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
PowerISA 3.0 encodes the segment size in the second half of hash page
table entry. Update hpte_decode() accordingly.
Fixes: 50de596de8 ("powerpc/mm/hash: Add support for Power9 Hash")
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
In some of the radix TLB flush routines, we use a local to store the
mm->context.id, AKA the PID.
Currently we use an int, but the PID is unsigned long, so large values
of PID will be truncated. In particular MMU_NO_CONTEXT is -1, which
means all our comparisons against that value can never be true.
This means we'll issue TLB flushes when we shouldn't on radix enabled
machines.
Fix it by using an unsigned long for the local. Discovered by Coverity.
Fixes: 1a472c9dba ("powerpc/mm/radix: Add tlbflush routines")
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Reviewed-by: Balbir Singh <bsingharora@gmail.com>
[mpe: Write change log]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Pull vfs fixes from Al Viro:
"Fixes for crap of assorted ages: EOPENSTALE one is 4.2+, autofs one is
4.6, d_walk - 3.2+.
The atomic_open() and coredump ones are regressions from this window"
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
coredump: fix dumping through pipes
fix a regression in atomic_open()
fix d_walk()/non-delayed __d_free() race
autofs braino fix for do_last()
fix EOPENSTALE bug in do_last()
The offset in the core file used to be tracked with ->written field of
the coredump_params structure. The field was retired in favour of
file->f_pos.
However, ->f_pos is not maintained for pipes which leads to breakage.
Restore explicit tracking of the offset in coredump_params. Introduce
->pos field for this purpose since ->written was already reused.
Fixes: a008393951 ("get rid of coredump_params->written").
Reported-by: Zbigniew Jędrzejewski-Szmek <zbyszek@in.waw.pl>
Signed-off-by: Mateusz Guzik <mguzik@redhat.com>
Reviewed-by: Omar Sandoval <osandov@fb.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
The recent commit 7cc851039d ("powerpc/pseries: Add POWER8NVL support
to ibm,client-architecture-support call") added a new PVR mask & value
to the start of the ibm_architecture_vec[] array.
However it missed the fact that further down in the array, we hard code
the offset of one of the fields, and then at boot use that value to
patch the value in the array. This means every update to the array must
also update the #define, ugh.
This means that on pseries machines we will misreport to firmware the
number of cores we support, by a factor of threads_per_core.
Fix it for now by updating the #define.
Fixes: 7cc851039d ("powerpc/pseries: Add POWER8NVL support to ibm,client-architecture-support call")
Cc: stable@vger.kernel.org # v4.0+
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
stragglers that didn't get merged by anyone this time around. Better to
do it now than wait for another one to pop up. There's also a minor
maintainers update and a Kconfig fix.
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Merge tag 'clk-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/clk/linux
Pull clk fixes from Stephen Boyd:
"This finally removes the CLK_IS_ROOT flag by picking up the last few
stragglers that didn't get merged by anyone this time around.
Better to do it now than wait for another one to pop up. There's also
a minor maintainers update and a Kconfig fix"
* tag 'clk-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/clk/linux:
clk: nxp: Select MFD_SYSCON for creg driver
MAINTAINERS: Add file patterns for clock device tree bindings
clk: Remove CLK_IS_ROOT flag
clk: microchip: Remove CLK_IS_ROOT
powerpc/512x: clk: Remove CLK_IS_ROOT
vexpress/spc: Remove CLK_IS_ROOT
