Commit Graph

17537 Commits

Author SHA1 Message Date
Madhavan Srinivasan
3b7e302086 powerpc: use generic atomic implementation for local_t
powerpc implements local_t with atomic operations. There is already
an asm-generic implementation which does this using atomic_t.

Signed-off-by: Madhavan Srinivasan <maddy@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-01-19 22:37:04 +11:00
Madhavan Srinivasan
c6424382de powerpc/64s: Add new set of irq_soft_mask_ functions for PMI masking
To support soft-masking of the performance monitor interrupt, a set of
new powerpc_local_irq_pmu_save() and powerpc_local_irq_restore()
functions are added. And powerpc_local_irq_save() implemented, by
adding a new irq_soft_mask manipulation function
irq_soft_mask_or_return().

Local_irq_pmu_* macros are provided to access these
powerpc_local_irq_pmu* functions which includes
trace_hardirqs_on|off() to match what we have in
include/linux/irqflags.h.

Signed-off-by: Madhavan Srinivasan <maddy@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-01-19 22:37:03 +11:00
Madhavan Srinivasan
9aa88188ee powerpc: Add new kconfig CONFIG_PPC_IRQ_SOFT_MASK_DEBUG
New Kconfig is added "CONFIG_PPC_IRQ_SOFT_MASK_DEBUG" to add WARN_ON
to alert the invalid transitions. Also moved the code under the
CONFIG_TRACE_IRQFLAGS in arch_local_irq_restore() to new Kconfig.

Reviewed-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Madhavan Srinivasan <maddy@linux.vnet.ibm.com>
[mpe: Fix name of CONFIG option in change log]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-01-19 22:37:03 +11:00
Madhavan Srinivasan
f442d00480 powerpc/64s: Add support to mask perf interrupts and replay them
Two new bit mask field "IRQ_DISABLE_MASK_PMU" is introduced to support
the masking of PMI and "IRQ_DISABLE_MASK_ALL" to aid interrupt masking
checking.

Couple of new irq #defs "PACA_IRQ_PMI" and "SOFTEN_VALUE_0xf0*" added
to use in the exception code to check for PMI interrupts.

In the masked_interrupt handler, for PMIs we reset the MSR[EE] and
return. In the __check_irq_replay(), replay the PMI interrupt by
calling performance_monitor_common handler.

Signed-off-by: Madhavan Srinivasan <maddy@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-01-19 22:37:02 +11:00
Madhavan Srinivasan
f14e953b19 powerpc/64s: Add support to take additional parameter in MASKABLE_* macro
To support addition of "bitmask" to MASKABLE_* macros, factor out the
EXCPETION_PROLOG_1 macro.

Make it explicit the interrupt masking supported by a gievn interrupt
handler. Patch correspondingly extends the MASKABLE_* macros with an
addition's parameter. "bitmask" parameter is passed to SOFTEN_TEST
macro to decide on masking the interrupt.

Signed-off-by: Madhavan Srinivasan <maddy@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-01-19 22:37:02 +11:00
Madhavan Srinivasan
d32eb1b550 powerpc/64s: Avoid using EXCEPTION_PROLOG_1 macro in MASKABLE_*
Currently we use both EXCEPTION_PROLOG_1 and __EXCEPTION_PROLOG_1 in
the MASKABLE_* macros. As a cleanup, this patch makes MASKABLE_* to
use only __EXCEPTION_PROLOG_1. There is not logic change.

Signed-off-by: Madhavan Srinivasan <maddy@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-01-19 22:37:01 +11:00
Madhavan Srinivasan
4e26bc4a4e powerpc/64: Rename soft_enabled to irq_soft_mask
Rename the paca->soft_enabled to paca->irq_soft_mask as it is no
longer used as a flag for interrupt state, but a mask.

Signed-off-by: Madhavan Srinivasan <maddy@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-01-19 22:37:01 +11:00
Madhavan Srinivasan
01417c6cc7 powerpc/64: Change soft_enabled from flag to bitmask
"paca->soft_enabled" is used as a flag to mask some of interrupts.
Currently supported flags values and their details:

soft_enabled    MSR[EE]

0               0       Disabled (PMI and HMI not masked)
1               1       Enabled

"paca->soft_enabled" is initialized to 1 to make the interripts as
enabled. arch_local_irq_disable() will toggle the value when
interrupts needs to disbled. At this point, the interrupts are not
actually disabled, instead, interrupt vector has code to check for the
flag and mask it when it occurs. By "mask it", it update interrupt
paca->irq_happened and return. arch_local_irq_restore() is called to
re-enable interrupts, which checks and replays interrupts if any
occured.

Now, as mentioned, current logic doesnot mask "performance monitoring
interrupts" and PMIs are implemented as NMI. But this patchset depends
on local_irq_* for a successful local_* update. Meaning, mask all
possible interrupts during local_* update and replay them after the
update.

So the idea here is to reserve the "paca->soft_enabled" logic. New
values and details:

soft_enabled    MSR[EE]

1               0       Disabled  (PMI and HMI not masked)
0               1       Enabled

Reason for the this change is to create foundation for a third mask
value "0x2" for "soft_enabled" to add support to mask PMIs. When
->soft_enabled is set to a value "3", PMI interrupts are mask and when
set to a value of "1", PMI are not mask. With this patch also extends
soft_enabled as interrupt disable mask.

Current flags are renamed from IRQ_[EN?DIS}ABLED to
IRQS_ENABLED and IRQS_DISABLED.

Patch also fixes the ptrace call to force the user to see the softe
value to be alway 1. Reason being, even though userspace has no
business knowing about softe, it is part of pt_regs. Like-wise in
signal context.

Signed-off-by: Madhavan Srinivasan <maddy@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-01-19 22:37:00 +11:00
Madhavan Srinivasan
acb396d7c2 powerpc/64: Cleanup hard_irq_disable() macro
Minor cleanup to use helper function for manipulating
paca->soft_enabled variable.

Suggested-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Madhavan Srinivasan <maddy@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-01-19 22:37:00 +11:00
Madhavan Srinivasan
a67c543aac powerpc/64: Implement and use soft_enabled_set_return API
Add a new wrapper function, soft_enabled_set_return(), added to do the
paca->soft_enabled updates requiring a set-return.

Signed-off-by: Madhavan Srinivasan <maddy@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-01-19 22:36:59 +11:00
Madhavan Srinivasan
e0b5687bed powerpc/64: Implement and use soft_enabled_return API
Add a new wrapper function, soft_enabled_return(), added to return
paca->soft_enabled value.

Signed-off-by: Madhavan Srinivasan <maddy@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-01-19 22:36:59 +11:00
Madhavan Srinivasan
0b63acf4a0 powerpc/64: Move set_soft_enabled() and rename
Move set_soft_enabled() from powerpc/kernel/irq.c to asm/hw_irq.c, to
encourage updates to paca->soft_enabled done via these access
function. Add "memory" clobber to hint compiler since
paca->soft_enabled memory is the target here.

Renaming it as soft_enabled_set() will make namespaces works better as
prefix than a postfix when new soft_enabled manipulation functions are
introduced.

Reviewed-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Madhavan Srinivasan <maddy@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-01-19 22:36:58 +11:00
Madhavan Srinivasan
b5c1bd62c0 powerpc/64: Fix arch_local_irq_disable() prototype
In powerpc/64, the arch_local_irq_disable() function returns unsigned
long, which is not consistent with other architectures.

Move that set-return asm implementation into arch_local_irq_save(),
and make arch_local_irq_disable() return void, simplifying the
assembly.

Suggested-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Madhavan Srinivasan <maddy@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-01-19 22:36:58 +11:00
Nicholas Piggin
9f83e00f4c powerpc/64: Improve inline asm in arch_local_irq_disable
arch_local_irq_disable is implemented strangely, with a temporary
output register being set to the desired soft_enabled value via an
immediate input, which is then used to store to memory. This is not
required, the immediate can be specified directly as a register input.

For simple cases at least, assembly is unchanged except register
mapping.

Reviewed-by: Madhavan Srinivasan <maddy@linux.vnet.ibm.com>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Madhavan Srinivasan <maddy@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-01-19 22:36:57 +11:00
Madhavan Srinivasan
c2e480ba82 powerpc/64: Add #defines for paca->soft_enabled flags
Two #defines IRQS_ENABLED and IRQS_DISABLED are added to be used when
updating paca->soft_enabled. Replace the hardcoded values used when
updating paca->soft_enabled with IRQ_(EN|DIS)ABLED #define. No logic
change.

Reviewed-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Madhavan Srinivasan <maddy@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-01-19 22:36:56 +11:00
Madhavan Srinivasan
a8a4b03ab9 powerpc: Hard wire PT_SOFTE value to 1 in ptrace & signals
We have always had softe in pt_regs, and accessible via PT_SOFTE, even
though it is not userspace state.

The value userspace sees should always be 1, because we should never
be in userspace with interrupts soft disabled.

In a subsequent patch we will be changing the semantics of the kernel
softe value, so hard wire the value to 1 to retain the existing
semantics. As far as we know nothing ever looks at it, but better safe
than sorry.

Signed-off-by: Madhavan Srinivasan <maddy@linux.vnet.ibm.com>
[mpe: Split out of larger patch, write change log]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-01-19 22:36:54 +11:00
Michael Ellerman
7a074fc083 powerpc/64s: Fix ps3 build error due to tlbiel_all()
The recent changes to TLB handling broke the PS3 build:

  arch/powerpc/include/asm/book3s/64/tlbflush.h:30: undefined reference to `.hash__tlbiel_all'

Fix it by adding an fallback version of tlbiel_all() for non-native
builds. It should never be called, due to checks in callers so it
calls BUG(). We should probably clean it up further but this will
suffice for now.

Fixes: d4748276ae ("powerpc/64s: Improve local TLB flush for boot and MCE on POWER9")
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-01-19 22:36:45 +11:00
Nicholas Piggin
c16bee4bde powerpc: define __ARCH_IRQ_EXIT_IRQS_DISABLED
powerpc calls irq_exit() with local irqs disabled, therefore it
can define __ARCH_IRQ_EXIT_IRQS_DISABLED.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-01-18 15:43:43 +11:00
Nicholas Piggin
47712a921b powerpc/watchdog: remove arch_trigger_cpumask_backtrace
The powerpc NMI IPIs may not be recoverable if they are taken in
some sections of code, and also there have been and still are issues
with taking NMIs (in KVM guest code, in firmware, etc) which makes them
a bit dangerous to use.

Generic code like softlockup detector and rcu stall detectors really
hammer on trigger_*_backtrace, which has lead to further problems
because we've implemented it with the NMI.

So stop providing NMI backtraces for now. Importantly, the powerpc code
uses NMI IPIs in crash/debug, and the SMP hardlockup watchdog. So if the
softlockup and rcu hang detection traces are not being printed because
the CPU is stuck with interrupts off, then the hard lockup watchdog
should get it with the NMI IPI.

Fixes: 2104180a53 ("powerpc/64s: implement arch-specific hardlockup watchdog")
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-01-18 15:43:43 +11:00
Nicholas Piggin
1af19331a3 powerpc/64s: Relax PACA address limitations
Book3S PACA memory allocation is restricted by the RMA limit and also
must not take SLB faults when accessed in virtual mode. Currently a
fixed 256MB limit is used for this, which is imprecise and sub-optimal.

Update the paca allocation limits to use use the ppc64_rma_size for RMA
limit, and share the safe_stack_limit() that is currently used for stack
allocations that must not take virtual mode faults.

The safe_stack_limit() name is changed to ppc64_bolted_size() to match
ppc64_rma_size and some comments are updated. We also need to use
early_mmu_has_feature() because we are now calling this function prior
to the jump label patching that enables mmu_has_feature().

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
[mpe: Change mmu_has_feature() to early_mmu_has_feature()]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-01-18 15:42:48 +11:00
Nicholas Piggin
c610d65c0a powerpc/pseries: lift RTAS limit for hash
With the previous patch to switch to 64-bit mode after returning from
RTAS and before doing any memory accesses, the RMA limit need not be
clamped to 1GB to avoid RTAS bugs.

Keep the 1GB limit for older firmware (although this is more of a kernel
concern than RTAS), and remove it starting with POWER9.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-01-18 00:45:34 +11:00
Nicholas Piggin
5eae82cab5 powerpc/pseries: lift RTAS limit for radix
With the previous patch to switch to 64-bit mode after returning from
RTAS and before doing any memory accesses, the RMA limit need not be
clamped to 1GB to avoid RTAS bugs.

Keep the 1GB limit for older firmware (although this is more of a kernel
concern than RTAS), and remove it starting with POWER9.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-01-18 00:44:42 +11:00
Nicholas Piggin
47fee31dbd powerpc/64: rtas avoid accessing paca in 32-bit mode
Commit 177ba7c647 ("powerpc/mm/radix: Limit paca allocation in radix")
limited the paca allocation address to 1G on pSeries because RTAS return
accesses the paca in 32-bit mode:

    On return from RTAS we access the paca variables and we have 64 bit
    disabled. This requires us to limit paca in 32 bit range.

    Fix this by setting ppc64_rma_size to first_memblock_size/1G range.

Avoid this limit by switching to 64-bit mode before accessing any memory.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-01-18 00:42:58 +11:00
Nicholas Piggin
98ae0069cb powerpc/pseries: radix is not subject to RMA limit, remove it
The radix guest is not subject to the paravirtualized HPT VRMA limit,
so remove that from ppc64_rma_size calculation for that platform.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-01-18 00:42:14 +11:00
Nicholas Piggin
1513c33d71 powerpc/powernv: Remove real mode access limit for early allocations
This removes the RMA limit on powernv platform, which constrains
early allocations such as PACAs and stacks. There are still other
restrictions that must be followed, such as bolted SLB limits, but
real mode addressing has no constraints.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-01-18 00:41:44 +11:00
Nicholas Piggin
d4748276ae powerpc/64s: Improve local TLB flush for boot and MCE on POWER9
There are several cases outside the normal address space management
where a CPU's entire local TLB is to be flushed:

  1. Booting the kernel, in case something has left stale entries in
     the TLB (e.g., kexec).

  2. Machine check, to clean corrupted TLB entries.

One other place where the TLB is flushed, is waking from deep idle
states. The flush is a side-effect of calling ->cpu_restore with the
intention of re-setting various SPRs. The flush itself is unnecessary
because in the first case, the TLB should not acquire new corrupted
TLB entries as part of sleep/wake (though they may be lost).

This type of TLB flush is coded inflexibly, several times for each CPU
type, and they have a number of problems with ISA v3.0B:

- The current radix mode of the MMU is not taken into account, it is
  always done as a hash flushn For IS=2 (LPID-matching flush from host)
  and IS=3 with HV=0 (guest kernel flush), tlbie(l) is undefined if
  the R field does not match the current radix mode.

- ISA v3.0B hash must flush the partition and process table caches as
  well.

- ISA v3.0B radix must flush partition and process scoped translations,
  partition and process table caches, and also the page walk cache.

So consolidate the flushing code and implement it in C and inline asm
under the mm/ directory with the rest of the flush code. Add ISA v3.0B
cases for radix and hash, and use the radix flush in radix environment.

Provide a way for IS=2 (LPID flush) to specify the radix mode of the
partition. Have KVM pass in the radix mode of the guest.

Take out the flushes from early cputable/dt_cpu_ftrs detection hooks,
and move it later in the boot process after, the MMU registers are set
up and before relocation is first turned on.

The TLB flush is no longer called when restoring from deep idle states.
This was not be done as a separate step because booting secondaries
uses the same cpu_restore as idle restore, which needs the TLB flush.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-01-18 00:40:31 +11:00
Nicholas Piggin
4552d128c2 powerpc: System reset avoid interleaving oops using die synchronisation
The die() oops path contains a serializing lock to prevent oops
messages from being interleaved. In the case of a system reset
initiated oops (e.g., qemu nmi command), __die was being called
which lacks that synchronisation and oops reports could be
interleaved across CPUs.

A recent patch 4388c9b3a6 ("powerpc: Do not send system reset
request through the oops path") changed this to __die to avoid
the debugger() call, but there is no real harm to calling it twice
if the first time fell through. So go back to using die() here.
This was observed to fix the problem.

Fixes: 4388c9b3a6 ("powerpc: Do not send system reset request through the oops path")
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-01-18 00:38:59 +11:00
Benjamin Herrenschmidt
2271db20e4 powerpc: Use the TRAP macro whenever comparing a trap number
Trap numbers can have extra bits at the bottom that need to
be filtered out. There are a few cases where we don't do that.

It's possible that we got lucky but better safe than sorry.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-01-16 23:51:43 +11:00
Benjamin Herrenschmidt
872e2ae4bd powerpc: Remove useless EXC_COMMON_HV
The only difference between EXC_COMMON_HV and EXC_COMMON is that the
former adds "2" to the trap number which is supposed to represent the
fact that this is an "HV" interrupt which uses HSRR0/1.

However KVM is the only one who cares and it has its own separate macros.

In fact, we only have one user of EXC_COMMON_HV and it's for an
unknown interrupt case. All the other ones already using EXC_COMMON.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-01-16 23:51:42 +11:00
Benjamin Herrenschmidt
f5abe14f88 powerpc/xive: Remove incorrect debug code
WORD2 if the TIMA isn't byte accessible and
isn't that useful to know about, take out the
pr_devel statement.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-01-16 23:48:04 +11:00
Benjamin Herrenschmidt
fbadeb6bb1 powerpc: Cosmetic cleanup of cpuinfo_op
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-01-16 23:47:16 +11:00
Benjamin Herrenschmidt
f5f563012a powerpc: Make newline in cpuinfo unconditional
We used to not put the newline between the CPU part and the summary
part on UP kernels. This is a rather pointless ifdef so take it out.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-01-16 23:47:15 +11:00
Benjamin Herrenschmidt
bba9bc89b9 powerpc: Add aacraid and nvme to powernv_defconfig
These adapters can be found in a number of our systems, so let's
enable the corresponding drivers by default.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-01-16 23:47:15 +11:00
Christophe Leroy
4f94b2c746 powerpc/8xx: Use L1 entry APG to handle _PAGE_ACCESSED for CONFIG_SWAP
When CONFIG_SWAP is set, the TLB miss handlers have to also take
into account _PAGE_ACCESSED flag. At the moment it is done by
anding _PAGE_ACCESSED into _PAGE_PRESENT using 3 instructions.

This patch uses APG for handling _PAGE_ACCESSED, allowing to
just copy _PAGE_ACCESSED bit into APG field, hence reducing the
action to a single instruction.

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-01-16 23:47:15 +11:00
Christophe Leroy
de0f938739 powerpc/8xx: Remove _PAGE_USER and handle user access at PMD level
As Linux kernel separates KERNEL and USER address spaces, there is
therefore no need to flag USER access at page level.

Today, the 8xx TLB handlers already handle user access in the L1 entry
through Access Protection Groups, it is then natural to move the user
access handling at PMD level once _PAGE_NA allows to handle PAGE_NONE
protection without _PAGE_USER

In the mean time, as we free up one bit in the PTE, we can use it to
include SPS (page size flag) in the PTE and avoid handling it at every
TLB miss hence removing special handling based on compiled page size.

For _PAGE_EXEC, we rework it to use PP PTE bits, avoiding the copy
of _PAGE_EXEC bit into the L1 entry. Unfortunatly we are not
able to put it at the correct location as it conflicts with
NA/RO/RW bits for data entries.

Upper bits of APG in L1 entry overlap with PMD base address. In
order to avoid having to filter that out, we set up all groups so that
upper bits can have any value.

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-01-16 23:47:14 +11:00
Christophe Leroy
351750331f powerpc/mm: Introduce _PAGE_NA
Today, PAGE_NONE is defined as a page not having _PAGE_USER.
In some circunstances, when the CPU supports it, it might be
better to be able to flag a page with NO ACCESS.

In a following patch, the 8xx will switch user access being flagged
in the PMD, therefore it will not be possible anymore to use
_PAGE_USER as a way to flag a page with no access.

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-01-16 23:47:14 +11:00
Christophe Leroy
812fadcb94 powerpc/mm: extend _PAGE_PRIVILEGED to all CPUs
commit ac29c64089 ("powerpc/mm: Replace _PAGE_USER with
_PAGE_PRIVILEGED") introduced _PAGE_PRIVILEGED for BOOK3S/64

This patch generalises _PAGE_PRIVILEGED for all CPUs, allowing
to have either _PAGE_PRIVILEGED or _PAGE_USER or both.

PPC_8xx has a _PAGE_SHARED flag which is set for and only for
all non user pages. Lets rename it _PAGE_PRIVILEGED to remove
confusion as it has nothing to do with Linux shared pages.

On BookE, there's a _PAGE_BAP_SR which has to be set for kernel
pages: defining _PAGE_PRIVILEGED as _PAGE_BAP_SR will make
this generic

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-01-16 23:47:13 +11:00
Christophe Leroy
5f356497c3 powerpc/8xx: remove unused _PAGE_WRITETHRU
_PAGE_WRITETHRU is only used in:
* AMIGA_Z2RAM block driver which is never activated on powerPC
* Video/FB driver which is for PPC_PMAC

Therefore, no need to spend time in 8xx TLB miss handlers for
handling it.

And by removing it, we free up bit 20 which then avoids having
to clear it on each TLB miss.

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-01-16 23:47:13 +11:00
Christophe Leroy
cd99ddbea2 powerpc/8xx: Only perform perf counting when perf is in use.
In TLB miss handlers, updating the perf counter is only useful
when performing a perf analysis. As it has a noticeable overhead,
let's only do it when needed.

In order to do so, the exit of the miss handlers will be patched
when starting/stopping 'perf': the first register restore
instruction of each exit point will be replaced by a jump to
the counting code.

Once this is done, CONFIG_PPC_8xx_PERF_EVENT becomes useless as
this feature doesn't add any overhead.

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-01-16 23:47:12 +11:00
Christophe Leroy
bb9b5a8332 powerpc/8xx: remove EXCEPTION_PROLOG/EPILOG_0 and change r3 to r12
EXCEPTION_PROLOG_0 and EXCEPTION_EPILOG_0 were added some
time ago in order to regroup the two mtspr/mfspr to SCRATCH0 and
SCRATCH1 and the mfcr/mtcr in order to ease entry and exit of
function not using the full EXCEPTION_PROLOG.

Since then, the mfcr/mtcr has been taken out, hence just leaving
the two mtspr/mfspr in the macro.

In order to improve readability of the exception functions, we
remove those two macros and copy back the two mtspr/mfspr instead.

As r10 and r11 are used for SCRATCH0 and SCRATCH1, lets also use
r12 for SCRATCH2. It will also improve the readability/maintenance.

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-01-16 23:47:12 +11:00
Christophe Leroy
2a45addd21 powerpc/8xx: Remove CPU6 ERRATA Workaround
CPU6 ERRATA affects only MPC860 revisions prior to C.0. Manufacturing
of those revisiosn was stopped in 1999-2000.
Therefore, it has been almost 20 years since this ERRATA has been
fixed in the silicon.

This patch removes the workaround for that ERRATA.

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-01-16 23:47:12 +11:00
Christophe Leroy
9a3b849bfe powerpc/8xx: do not select CONFIG_PPC_LIB_RHEAP
Since commit 0e6e01ff69 ("CPM/QE: use genalloc to manage CPM/QE
muram"), rheap is not used anymore.

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-01-16 23:47:11 +11:00
Balbir Singh
4145f35864 powernv/kdump: Fix cases where the kdump kernel can get HMI's
Certain HMI's such as malfunction error propagate through
all threads/core on the system. If a thread was offline
prior to us crashing the system and jumping to the kdump
kernel, bad things happen when it wakes up due to an HMI
in the kdump kernel.

There are several possible ways to solve this problem

1. Put the offline cores in a state such that they are
not woken up for machine check and HMI errors. This
does not work, since we might need to wake up offline
threads to handle TB errors
2. Ignore HMI errors, setup HMEER to mask HMI errors,
but this still leads the window open for any MCEs
and masking them for the duration of the dump might
be a concern
3. Wake up offline CPUs, as in send them to
crash_ipi_callback (not wake them up as in mark them
online as seen by the hotplug). kexec does a
wake_online_cpus() call, this patch does something
similar, but instead sends an IPI and forces them to
crash_ipi_callback()

This patch takes approach #3.

Care is taken to enable this only for powenv platforms
via crash_wake_offline (a global value set at setup
time). The crash code sends out IPI's to all CPU's
which then move to crash_ipi_callback and kexec_smp_wait().

Signed-off-by: Balbir Singh <bsingharora@gmail.com>
Reviewed-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-01-16 23:47:11 +11:00
Balbir Singh
04b9c96eae powerpc/crash: Remove the test for cpu_online in the IPI callback
Our check was extra cautious, we've audited crash_send_ipi
and it sends an IPI only to online CPU's. Removal of this
check should have not functional impact on crash kdump.

Signed-off-by: Balbir Singh <bsingharora@gmail.com>
Reviewed-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-01-16 23:47:10 +11:00
Dmitry Torokhov
9625e69a38 powerpc: make use of for_each_node_by_type() instead of open-coding it
Instead of manually coding the loop with of_find_node_by_type(), let's
switch to the standard macro for iterating over nodes with given type.

Also fixed a couple of refcount leaks in the aforementioned loops.

Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-01-16 23:47:10 +11:00
Christophe Leroy
94d3084a0f powerpc/32s: Fix compile error with CONFIG_PPC_PTDUMP
This patch remove CONFIG_PPC_HTDUMP if not PPC_BOOK3S_64 to avoid
below compile failure on BOOK3S_32:

  In file included from arch/powerpc/mm/dump_hashpagetable.c:27:0:
  ./arch/powerpc/include/asm/plpar_wrappers.h: In function 'get_cede_latency_hint':
  ./arch/powerpc/include/asm/plpar_wrappers.h:27:2: error: implicit declaration of function 'get_lppaca' [-Werror=implicit-function-declaration]
  ...
  arch/powerpc/mm/dump_hashpagetable.c: At top level:
  arch/powerpc/mm/dump_hashpagetable.c:69:13: error: 'SLB_VSID_B' undeclared here (not in a function)
  ...
  arch/powerpc/mm/dump_hashpagetable.c:506:38: error: 'VMEMMAP_BASE' undeclared (first use in this function)
  arch/powerpc/mm/dump_hashpagetable.c:506:35: error: assignment makes integer from pointer without a cast [-Werror]

Fixes: dd5ac03e09 ("powerpc/mm: Fix page table dump build on non-Book3S")
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
[mpe: Trim change log]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-01-16 23:35:02 +11:00
Nathan Fontenot
0c38ed6f6f powerpc/pseries: Enable support of ibm,dynamic-memory-v2
Add required bits to the architecture vector to enable support
of the ibm,dynamic-memory-v2 device tree property.

Signed-off-by: Nathan Fontenot <nfont@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-01-16 23:26:30 +11:00
Nathan Fontenot
2b31e3aec1 powerpc/drmem: Add support for ibm, dynamic-memory-v2 property
The Power Hypervisor has introduced a new device tree format for
the property describing the dynamic reconfiguration LMBs for a system,
ibm,dynamic-memory-v2. This new format condenses the size of the
property, especially on large memory systems, by reporting sets
of LMBs that have the same properties (flags and associativity array
index).

This patch updates the powerpc/mm/drmem.c code to provide routines
that can parse the new device tree format during the walk_drmem_lmb*
routines used during boot, the creation of the LMB array, and updating
the device tree to create a new property in the proper format for
ibm,dynamic-memory-v2.

Signed-off-by: Nathan Fontenot <nfont@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-01-16 23:26:29 +11:00
Nathan Fontenot
2c77721552 powerpc: Move of_drconf_cell struct to asm/drmem.h
Now that the powerpc code parses dynamic reconfiguration memory
LMB information from the LMB array and not the device tree
directly we can move the of_drconf_cell struct to drmem.h where
it fits better.

In addition, the struct is renamed to of_drconf_cell_v1 in
anticipation of upcoming support for version 2 of the dynamic
reconfiguration property and the members are typed as __be*
values to reflect how they exist in the device tree.

Signed-off-by: Nathan Fontenot <nfont@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-01-16 23:26:29 +11:00
Nathan Fontenot
6195a5001f powerpc/pseries: Update memory hotplug code to use drmem LMB array
Update the pseries memory hotplug code to use the newly added
dynamic reconfiguration LMB array. Doing this is required for the
upcoming support of version 2 of the dynamic reconfiguration
device tree property.

In addition, making this change cleans up the code that parses the
LMB information as we no longer need to worry about device tree
format. This allows us to discard one of the first steps on memory
hotplug where we make a working copy of the device tree property and
convert the entire property to cpu format. Instead we just use the
LMB array directly while holding the memory hotplug lock.

This patch also moves the updating of the device tree property to
powerpc/mm/drmem.c. This allows to the hotplug code to work without
needing to know the device tree format and provides a single
routine for updating the device tree property. This new routine
will handle determination of the proper device tree format and
generate a properly formatted device tree property.

Signed-off-by: Nathan Fontenot <nfont@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-01-16 23:26:28 +11:00