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When support for EEH on PowerNV was added a lot of pseries specific code
was made "generic" and some of the quirks of pseries EEH came along for the
ride. One of the stranger quirks is eeh_pe containing two types of PE
address: pe->addr and pe->config_addr. There reason for this appears to be
historical baggage rather than any real requirements.
On pseries EEH PEs are manipulated using RTAS calls. Each EEH RTAS call
takes a "PE configuration address" as an input which is used to identify
which EEH PE is being manipulated by the call. When initialising the EEH
state for a device the first thing we need to do is determine the
configuration address for the PE which contains the device so we can enable
EEH on that PE. This process is outlined in PAPR which is the modern
(i.e post-2003) FW specification for pseries. However, EEH support was
first described in the pSeries RISC Platform Architecture (RPA) and
although they are mostly compatible EEH is one of the areas where they are
not.
The major difference is that RPA doesn't actually have the concept of a PE.
On RPA systems the EEH RTAS calls are done on a per-device basis using the
same config_addr that would be passed to the RTAS functions to access PCI
config space (e.g. ibm,read-pci-config). The config_addr is not identical
since the function and config register offsets of the config_addr must be
set to zero. EEH operations being done on a per-device basis doesn't make a
whole lot of sense when you consider how EEH was implemented on legacy PCI
systems.
For legacy PCI(-X) systems EEH was implemented using special PCI-PCI
bridges which contained logic to detect errors and freeze the secondary
bus when one occurred. This means that the EEH enabled state is shared
among all devices behind that EEH bridge. As a result there's no way to
implement the per-device control required for the semantics specified by
RPA. It can be made to work if we assume that a separate EEH bridge exists
for each EEH capable PCI slot and there are no bridges behind those slots.
However, RPA also specifies the ibm,configure-bridge RTAS call for
re-initalising bridges behind EEH capable slots after they are reset due
to an EEH event so that is probably not a valid assumption. This
incoherence was fixed in later PAPR, which succeeded RPA. Unfortunately,
since Linux EEH support seems to have been implemented based on the RPA
spec some of the legacy assumptions were carried over (probably for POWER4
compatibility).
The fix made in PAPR was the introduction of the "PE" concept and
redefining the EEH RTAS calls (set-eeh-option, reset-slot, etc) to operate
on a per-PE basis so all devices behind an EEH bride would share the same
EEH state. The "config_addr" argument to the EEH RTAS calls became the
"PE_config_addr" and the OS was required to use the
ibm,get-config-addr-info RTAS call to find the correct PE address for the
device. When support for the new interfaces was added to Linux it was
implemented using something like:
At probe time:
pdn->eeh_config_addr = rtas_config_addr(pdn);
pdn->eeh_pe_config_addr = rtas_get_config_addr_info(pdn);
When performing an RTAS call:
config_addr = pdn->eeh_config_addr;
if (pdn->eeh_pe_config_addr)
config_addr = pdn->eeh_pe_config_addr;
rtas_call(..., config_addr, ...);
In other words, if the ibm,get-config-addr-info RTAS call is implemented
and returned a valid result we'd use that as the argument to the EEH
RTAS calls. If not, Linux would fall back to using the device's
config_addr. Over time these addresses have moved around going from pci_dn
to eeh_dev and finally into eeh_pe. Today the users look like this:
config_addr = pe->config_addr;
if (pe->addr)
config_addr = pe->addr;
rtas_call(..., config_addr, ...);
However, considering the EEH core always operates on a per-PE basis and
even on pseries the only per-device operation is the initial call to
ibm,set-eeh-option I'm not sure if any of this actually works on an RPA
system today. It doesn't make much sense to have the fallback address in
a generic structure either since the bulk of the code which reference it
is in pseries anyway.
The EEH core makes a token effort to support looking up a PE using the
config_addr by having two arguments to eeh_pe_get(). However, a survey of
all the callers to eeh_pe_get() shows that all bar one have the config_addr
argument hard-coded to zero.The only caller that doesn't is in
eeh_pe_tree_insert() which has:
if (!eeh_has_flag(EEH_VALID_PE_ZERO) && !edev->pe_config_addr)
return -EINVAL;
pe = eeh_pe_get(hose, edev->pe_config_addr, edev->bdfn);
The third argument (config_addr) is only used if the second (pe->addr)
argument is invalid. The preceding check ensures that the call to
eeh_pe_get() will never happen if edev->pe_config_addr is invalid so there
is no situation where eeh_pe_get() will search for a PE based on the 3rd
argument. The check also means that we'll never insert a PE into the tree
where pe_config_addr is zero since EEH_VALID_PE_ZERO is never set on
pseries. All the users of the fallback address on pseries never actually
use the fallback and all the only caller that supplies something for the
config_addr argument to eeh_pe_get() never use it either. It's all dead
code.
This patch removes the fallback address from eeh_pe since nothing uses it.
Specificly, we do this by:
1) Removing pe->config_addr
2) Removing the EEH_VALID_PE_ZERO flag
3) Removing the fallback address argument to eeh_pe_get().
4) Removing all the checks for pe->addr being zero in the pseries EEH code.
This leaves us with PE's only being identified by what's in their pe->addr
field and the EEH core relying on the platform to ensure that eeh_dev's are
only inserted into the EEH tree if they're actually inside a PE.
No functional changes, I hope.
Signed-off-by: Oliver O'Halloran <oohall@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200918093050.37344-9-oohall@gmail.com
There's no real reason why zero can't be a valid PE configuration address.
Under qemu each sPAPR PHB (i.e. EEH supporting) has the passed-though
devices on bus zero, so the PE address of bus <dddd>:00 should be zero.
However, all previous versions of Linux will reject that, so Qemu at least
goes out of it's way to avoid it. The Qemu implementation of
ibm,get-config-addr-info2 RTAS has the following comment:
> /*
> * We always have PE address of form "00BB0001". "BB"
> * represents the bus number of PE's primary bus.
> */
So qemu puts a one into the register portion of the PE's config_addr to
avoid it being zero. The whole is pretty silly considering that RTAS will
return a negative error code if it can't map the device's config_addr to a
PE.
This patch fixes Linux to treat zero as a valid PE address. This shouldn't
have any real effects due to the Qemu hack mentioned above. And the fact
that Linux EEH has worked historically on PowerVM means they never pass
through devices on bus zero so we would never see the problem there either.
Signed-off-by: Oliver O'Halloran <oohall@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200918093050.37344-8-oohall@gmail.com
The process Linux uses for determining if a device supports EEH or not
appears to be at odds with what PAPR says the OS should be doing. The
current flow is something like:
1. Assume pe_config_addr is equal the the device's config_addr.
2. Attempt to enable EEH on that PE
3. Verify EEH was enabled (POWER4 bug workaround)
4. Try find the pe_config_addr using the ibm,get-config-addr-info2 RTAS
call.
5. If that fails walk the pci_dn tree upwards trying to find a parent
device with EEH support. If we find one then add the device to that PE.
The first major problem with this process is that we need the PE config
address in step 2) since its needs to be passed to the ibm,set-eeh-option
RTAS call when enabling EEH for th PE. We hack around this requirement in
by making the assumption in 1) and delay finding the actual PE address
until 4). This is fine if:
a) The PCI device is the 0th function, and
b) The device is on the PE's root bus.
Granted, the current sequence does appear to work on most systems even when
these conditions are false. At a guess PowerVM's RTAS has workarounds to
accommodate Linux's quirks or the RTAS call to enable EEH is treated as
no-op on most platforms since EEH is usually enabled by default. However,
what is currently implemented is a bit sketch and is downright confusing
since it doesn't match up with what what PAPR suggests we should be doing.
This patch re-works how we handle EEH init so that we find the PE config
address using the ibm,get-config-addr-info2 RTAS call first, then use the
found address to finish the EEH init process. It also drops the Power4
workaround since as of commit 471d7ff8b5 ("powerpc/64s: Remove POWER4
support") the kernel does not support running on a Power4 CPU so there's
no need to support the Power4 platform's quirks either. With the patch
applied the sequence is now:
1. Find the pe_config_addr from the device using the RTAS call.
2. Enable the PE.
3. Insert the edev into the tree and create an eeh_pe if needed.
The other change made here is ignoring unsupported devices entirely.
Currently the device's BARs are saved to the eeh_dev even if the device is
not part of an EEH PE. Not being part of a PE means that an EEH recovery
pass will never see that device so the saving the BARs is pointless.
Signed-off-by: Oliver O'Halloran <oohall@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200918093050.37344-7-oohall@gmail.com
De-duplicate, and fix up the comments, and make the prototype just take a
pci_dn since the job of the function is to return the pe_config_addr of the
PE which contains a given device.
Signed-off-by: Oliver O'Halloran <oohall@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200918093050.37344-6-oohall@gmail.com
The initialisation of EEH mostly happens in a core_initcall_sync initcall,
followed by registering a bus notifier later on in an arch_initcall.
Anything involving initcall dependecies is mostly incomprehensible unless
you've spent a while staring at code so here's the full sequence:
ppc_md.setup_arch <-- pci_controllers are created here
...time passes...
core_initcall <-- pci_dns are created from DT nodes
core_initcall_sync <-- platforms call eeh_init()
postcore_initcall <-- PCI bus type is registered
postcore_initcall_sync
arch_initcall <-- EEH pci_bus notifier registered
subsys_initcall <-- PHBs are scanned here
There's no real requirement to do the EEH setup at the core_initcall_sync
level. It just needs to be done after pci_dn's are created and before we
start scanning PHBs. Simplify the flow a bit by moving the platform EEH
inititalisation to an arch_initcall so we can fold the bus notifier
registration into eeh_init().
Signed-off-by: Oliver O'Halloran <oohall@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200918093050.37344-5-oohall@gmail.com
No longer used since the platforms perform their EEH initialisation before
calling eeh_init().
Signed-off-by: Oliver O'Halloran <oohall@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200918093050.37344-4-oohall@gmail.com
Fold pseries_eeh_init() into eeh_pseries_init() rather than having
eeh_init() call it via eeh_ops->init(). It's simpler and it'll let us
delete eeh_ops.init.
Signed-off-by: Oliver O'Halloran <oohall@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200918093050.37344-3-oohall@gmail.com
Fold pnv_eeh_init() into eeh_powernv_init() rather than having eeh_init()
call it via eeh_ops->init(). It's simpler and it'll let us delete
eeh_ops.init.
Signed-off-by: Oliver O'Halloran <oohall@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200918093050.37344-2-oohall@gmail.com
Drop the EEH register / unregister ops thing and have the platform pass the
ops structure into eeh_init() directly. This takes one initcall out of the
EEH setup path and it means we're only doing EEH setup on the platforms
which actually support it. It's also less code and generally easier to
follow.
No functional changes.
Signed-off-by: Oliver O'Halloran <oohall@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200918093050.37344-1-oohall@gmail.com
Switch the 85xx defconfigs from the soon to be removed legacy ide
driver to libata.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200924041310.520970-1-hch@lst.de
In commit 61f879d97c ("powerpc/pseries: Detect secure and trusted
boot state of the system.") we taught the kernel how to understand the
secure-boot parameters used by a pseries guest.
However, CONFIG_PPC_SECURE_BOOT still requires PowerNV. I didn't
catch this because pseries_le_defconfig includes support for
PowerNV and so everything still worked. Indeed, most configs will.
Nonetheless, technically PPC_SECURE_BOOT doesn't require PowerNV
any more.
The secure variables support (PPC_SECVAR_SYSFS) doesn't do anything
on pSeries yet, but I don't think it's worth adding a new condition -
at some stage we'll want to add a backend for pSeries anyway.
Fixes: 61f879d97c ("powerpc/pseries: Detect secure and trusted boot state of the system.")
Signed-off-by: Daniel Axtens <dja@axtens.net>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200924014922.172914-1-dja@axtens.net
Build the kernel with 'make C=2':
arch/powerpc/platforms/pseries/papr_scm.c:825:1: warning: symbol
'dev_attr_perf_stats' was not declared. Should it be static?
Signed-off-by: Wang Wensheng <wangwensheng4@huawei.com>
Reviewed-by: Vaibhav Jain <vaibhav@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200918085951.44983-1-wangwensheng4@huawei.com
Since the assembly soft-masking code was moved to 64e specific, there
are some 64s specific interrupt types still there. Remove them.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200915114650.3980244-4-npiggin@gmail.com
Replayed interrupts get an "artificial" struct pt_regs constructed to
pass to interrupt handler functions. This did not get the softe field
set correctly, it's as though the interrupt has hit while irqs are
disabled. It should be IRQS_ENABLED.
This is possibly harmless, asynchronous handlers should not be testing
if irqs were disabled, but it might be possible for example some code
is shared with synchronous or NMI handlers, and it makes more sense if
debug output looks at this.
Fixes: 3282a3da25 ("powerpc/64: Implement soft interrupt replay in C")
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200915114650.3980244-2-npiggin@gmail.com
Prior to commit 3282a3da25 ("powerpc/64: Implement soft interrupt
replay in C"), replayed interrupts returned by the regular interrupt
exit code, which performs preemption in case an interrupt had set
need_resched.
This logic was missed by the conversion. Adding preempt_disable/enable
around the interrupt replay and final irq enable will reschedule if
needed.
Fixes: 3282a3da25 ("powerpc/64: Implement soft interrupt replay in C")
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200915114650.3980244-1-npiggin@gmail.com
The hypervisor interface has defined branch prediction security bits for
handling the link stack. Wire them up.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200825075612.224656-1-npiggin@gmail.com
The copy buffer is implemented as a real address in the nest which is
translated from EA by copy, and used for memory access by paste. This
requires that it be invalidated by TLB invalidation.
TLBIE does invalidate the copy buffer, but TLBIEL does not. Add
cp_abort to the tlbiel sequence.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
[mpe: Fixup whitespace and comment formatting]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200916030234.4110379-2-npiggin@gmail.com
Having cputable.h include mce.h means it pulls in a bunch of low level
headers (e.g., synch.h) which then can't use CPU_FTR_ definitions.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200916030234.4110379-1-npiggin@gmail.com
Every error log reported by OPAL is exported to userspace through a
sysfs interface and notified using kobject_uevent(). The userspace
daemon (opal_errd) then reads the error log and acknowledges the error
log is saved safely to disk. Once acknowledged the kernel removes the
respective sysfs file entry causing respective resources to be
released including kobject.
However it's possible the userspace daemon may already be scanning
elog entries when a new sysfs elog entry is created by the kernel.
User daemon may read this new entry and ack it even before kernel can
notify userspace about it through kobject_uevent() call. If that
happens then we have a potential race between
elog_ack_store->kobject_put() and kobject_uevent which can lead to
use-after-free of a kernfs object resulting in a kernel crash. eg:
BUG: Unable to handle kernel data access on read at 0x6b6b6b6b6b6b6bfb
Faulting instruction address: 0xc0000000008ff2a0
Oops: Kernel access of bad area, sig: 11 [#1]
LE PAGE_SIZE=64K MMU=Hash SMP NR_CPUS=2048 NUMA PowerNV
CPU: 27 PID: 805 Comm: irq/29-opal-elo Not tainted 5.9.0-rc2-gcc-8.2.0-00214-g6f56a67bcbb5-dirty #363
...
NIP kobject_uevent_env+0xa0/0x910
LR elog_event+0x1f4/0x2d0
Call Trace:
0x5deadbeef0000122 (unreliable)
elog_event+0x1f4/0x2d0
irq_thread_fn+0x4c/0xc0
irq_thread+0x1c0/0x2b0
kthread+0x1c4/0x1d0
ret_from_kernel_thread+0x5c/0x6c
This patch fixes this race by protecting the sysfs file
creation/notification by holding a reference count on kobject until we
safely send kobject_uevent().
The function create_elog_obj() returns the elog object which if used
by caller function will end up in use-after-free problem again.
However, the return value of create_elog_obj() function isn't being
used today and there is no need as well. Hence change it to return
void to make this fix complete.
Fixes: 774fea1a38 ("powerpc/powernv: Read OPAL error log and export it through sysfs")
Cc: stable@vger.kernel.org # v3.15+
Reported-by: Oliver O'Halloran <oohall@gmail.com>
Signed-off-by: Mahesh Salgaonkar <mahesh@linux.ibm.com>
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Reviewed-by: Oliver O'Halloran <oohall@gmail.com>
Reviewed-by: Vasant Hegde <hegdevasant@linux.vnet.ibm.com>
[mpe: Rework the logic to use a single return, reword comments, add oops]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20201006122051.190176-1-mpe@ellerman.id.au
This fixes a compile error with W=1.
CC arch/powerpc/kernel/traps.o
../arch/powerpc/kernel/traps.c:1663:6: error: no previous prototype for ‘stack_overflow_exception’ [-Werror=missing-prototypes]
void stack_overflow_exception(struct pt_regs *regs)
^~~~~~~~~~~~~~~~~~~~~~~~
Fixes: 3978eb7851 ("powerpc/32: Add early stack overflow detection with VMAP stack.")
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Reviewed-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200914211007.2285999-8-clg@kaod.org
The check should be performed by the caller. This fixes a compile
error with W=1.
../arch/powerpc/lib/sstep.c: In function ‘mlsd_8lsd_ea’:
../arch/powerpc/lib/sstep.c:225:3: error: suggest braces around empty body in an ‘if’ statement [-Werror=empty-body]
; /* Invalid form. Should already be checked for by caller! */
^
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200914211007.2285999-4-clg@kaod.org
This fixes a compile error with W=1.
arch/powerpc/kernel/sysfs.c: In function ‘sysfs_create_dscr_default’:
arch/powerpc/kernel/sysfs.c:228:7: error: variable ‘err’ set but not used [-Werror=unused-but-set-variable]
int err = 0;
^~~
cc1: all warnings being treated as errors
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Reviewed-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200914211007.2285999-2-clg@kaod.org
It's possible to enable CONFIG_PPC_EARLY_DEBUG_BOOTX for a pseries
kernel (maybe it shouldn't be), which is then booted with qemu/slof.
But if you do that the kernel crashes in draw_byte(), with a DAR
pointing somewhere near INT_MAX.
Adding some debug to prom_init we see that we're not able to read the
"address" property from OF, so we're just using whatever junk value
was on the stack.
So check the properties can be read properly from OF, if not we bail
out before initialising btext, which avoids the crash.
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Reviewed-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Link: https://lore.kernel.org/r/20200821103407.3362149-1-mpe@ellerman.id.au
We have smp_ops->cpu_die() and ppc_md.cpu_die(). One of them offlines
the current CPU and one offlines another CPU, can you guess which is
which? Also one is in smp_ops and one is in ppc_md?
So rename ppc_md.cpu_die(), to cpu_offline_self(), because that's what
it does. And move it into smp_ops where it belongs.
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200819015634.1974478-3-mpe@ellerman.id.au
arch_cpu_idle_dead() is in idle.c, which makes sense, but it's inside
a CONFIG_HOTPLUG_CPU block.
It would be more at home in smp.c, inside the existing
CONFIG_HOTPLUG_CPU block. Note that CONFIG_HOTPLUG_CPU depends on
CONFIG_SMP so even though smp.c is not built for SMP=n builds, that's
fine.
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200819015634.1974478-1-mpe@ellerman.id.au
Sparse warns about all the init functions:
symbol init_ppc970_pmu was not declared. Should it be static?
symbol init_power5p_pmu was not declared. Should it be static?
symbol init_power5_pmu was not declared. Should it be static?
symbol init_power6_pmu was not declared. Should it be static?
symbol init_power7_pmu was not declared. Should it be static?
symbol init_power9_pmu was not declared. Should it be static?
symbol init_power8_pmu was not declared. Should it be static?
symbol init_generic_compat_pmu was not declared. Should it be static?
They're already declared in internal.h, so just make sure all the C
files include that directly or indirectly.
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Reviewed-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Link: https://lore.kernel.org/r/20200916115637.3100484-2-mpe@ellerman.id.au
Fix link error when CONFIG_PPC_RADIX_MMU is disabled:
powerpc64-linux-gnu-ld: arch/powerpc/platforms/pseries/lpar.o:(.toc+0x0): undefined reference to `mmu_pid_bits'
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200917020643.90375-1-yangyingliang@huawei.com
Clang, and GCC with -Wmaybe-uninitialized, can't see that val is
unused in get_fpexec_mode():
arch/powerpc/kernel/process.c:1940:7: error: variable 'val' is used
uninitialized whenever 'if' condition is true
if (cpu_has_feature(CPU_FTR_SPE)) {
^~~~~~~~~~~~~~~~~~~~~~~~~~~~
We know that CPU_FTR_SPE will only be true iff CONFIG_SPE is also
true, but the compiler doesn't.
Avoid it by initialising val to zero.
Reported-by: kernel test robot <lkp@intel.com>
Fixes: 532ed1900d ("powerpc/process: Remove useless #ifdef CONFIG_SPE")
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Tested-by: Nick Desaulniers <ndesaulniers@google.com>
Link: https://lore.kernel.org/r/20200917024509.3253837-1-mpe@ellerman.id.au
Lookup the coregroup id from the associativity array.
If unable to detect the coregroup id, fallback on the core id.
This way, ensure sched_domain degenerates and an extra sched domain is
not created.
Ideally this function should have been implemented in
arch/powerpc/kernel/smp.c. However if its implemented in mm/numa.c, we
don't need to find the primary domain again.
If the device-tree mentions more than one coregroup, then kernel
implements only the last or the smallest coregroup, which currently
corresponds to the penultimate domain in the device-tree.
Signed-off-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Reviewed-by: Gautham R. Shenoy <ego@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200810071834.92514-11-srikar@linux.vnet.ibm.com
Add percpu coregroup maps and masks to create coregroup domain.
If a coregroup doesn't exist, the coregroup domain will be degenerated
in favour of SMT/CACHE domain. Do note this patch is only creating stubs
for cpu_to_coregroup_id. The actual cpu_to_coregroup_id implementation
would be in a subsequent patch.
Signed-off-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Reviewed-by: Gautham R. Shenoy <ego@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200810071834.92514-10-srikar@linux.vnet.ibm.com
If allocated earlier and the search fails, then cpu_l1_cache_map cpumask
is unnecessarily cleared. However cpu_l1_cache_map can be allocated /
cleared after we search thread group.
Please note CONFIG_CPUMASK_OFFSTACK is not set on Powerpc. Hence cpumask
allocated by zalloc_cpumask_var_node is never freed.
Signed-off-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Reviewed-by: Gautham R. Shenoy <ego@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200810071834.92514-9-srikar@linux.vnet.ibm.com
Add support for grouping cores based on the device-tree classification.
- The last domain in the associativity domains always refers to the
core.
- If primary reference domain happens to be the penultimate domain in
the associativity domains device-tree property, then there are no
coregroups. However if its not a penultimate domain, then there are
coregroups. There can be more than one coregroup. For now we would be
interested in the last or the smallest coregroups, i.e one sub-group
per DIE.
Currently there are no firmwares that are exposing this grouping. Hence
allow the basis for grouping to be abstract. Once the firmware starts
using this grouping, code would be added to detect the type of grouping
and adjust the sd domain flags accordingly.
Signed-off-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Reviewed-by: Gautham R. Shenoy <ego@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200810071834.92514-8-srikar@linux.vnet.ibm.com
In start_secondary, even if shared_cache was already set, system does a
redundant match for cpumask. This redundant check can be removed by
checking if shared_cache is already set.
While here, localize the sibling_mask variable to within the if
condition.
Signed-off-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Reviewed-by: Gautham R. Shenoy <ego@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200810071834.92514-7-srikar@linux.vnet.ibm.com
Current code assumes that cpumask of cpus sharing a l2-cache mask will
always be a superset of cpu_sibling_mask.
Lets stop that assumption. cpu_l2_cache_mask is a superset of
cpu_sibling_mask if and only if shared_caches is set.
Reviewed-by: Gautham R. Shenoy <ego@linux.vnet.ibm.com>
Signed-off-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200913171038.GB11808@linux.vnet.ibm.com
Move topology fixup based on the platform attributes into its own
function which is called just before set_sched_topology.
Signed-off-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Reviewed-by: Gautham R. Shenoy <ego@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200810071834.92514-5-srikar@linux.vnet.ibm.com
Just moving the powerpc_topology description above.
This will help in using functions in this file and avoid declarations.
No other functional changes
Signed-off-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Reviewed-by: Gautham R. Shenoy <ego@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200810071834.92514-4-srikar@linux.vnet.ibm.com
A new sched_domain_topology_level was added just for Power9. However the
same can be achieved by merging powerpc_topology with power9_topology
and makes the code more simpler especially when adding a new sched
domain.
Signed-off-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Reviewed-by: Gautham R. Shenoy <ego@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200810071834.92514-3-srikar@linux.vnet.ibm.com
Fix a build warning in a non CONFIG_NEED_MULTIPLE_NODES
"error: _numa_cpu_lookup_table_ undeclared"
Signed-off-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Reviewed-by: Gautham R. Shenoy <ego@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200810071834.92514-2-srikar@linux.vnet.ibm.com
