This moves the _PAGE_SPECIAL and _PAGE_SOFT_DIRTY bits in the Linux
PTE on 64-bit Book 3S systems to bit positions which are designated
for software use in the radix PTE format used by PowerISA v3.0 CPUs
in radix mode.
Signed-off-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

This moves the _PAGE_EXEC, _PAGE_RW and _PAGE_USER bits around in
the Linux PTE on 64-bit Book 3S systems to correspond with the bit
positions used in radix mode by PowerISA v3.0 CPUs.  This also adds
a _PAGE_READ bit corresponding to the read permission bit in the
radix PTE.  _PAGE_READ is currently unused but could possibly be used
in future to improve pte_protnone().
Signed-off-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

This moves the _PAGE_HASHPTE, _PAGE_F_GIX and _PAGE_F_SECOND fields in
the Linux PTE on 64-bit Book 3S systems to the most significant byte.
Of the 5 bits, one is a software-use bit and the other four are
reserved bit positions in the PowerISA v3.0 radix PTE format.
Using these bits is OK because these bits are all to do with tracking
the HPTE(s) associated with the Linux PTE, and therefore won't be
needed in radix mode.  This frees up bit positions in the lower two
bytes.
Signed-off-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

This changes _PAGE_PTE for 64-bit Book 3S processors from 0x1 to
0x4000_0000_0000_0000, because that bit is used as the L (leaf)
bit by PowerISA v3.0 CPUs in radix mode.  The "leaf" bit indicates
that the PTE points to a page directly rather than another radix
level, which is what the _PAGE_PTE bit means.
Signed-off-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

This changes _PAGE_PRESENT for 64-bit Book 3S processors from 0x2 to
0x8000_0000_0000_0000, because that is where PowerISA v3.0 CPUs in
radix mode will expect to find it.
Signed-off-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

This changes the Linux page tables to store physical addresses
rather than kernel virtual addresses in the upper levels of the
tree (pgd, pud and pmd) for 64-bit Book 3S machines.

This also changes the hugepd pointers used to implement hugepages
when the base page size is 4k to store physical addresses rather than
virtual addresses (again just for 64-bit Book3S machines).

This frees up some high order bits, and will be needed with
PowerISA v3.0 machines which read the page table tree in hardware
in radix mode.
Signed-off-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

This frees up bits 57-63 in the Linux PTE on 64-bit Book 3S machines.
In the 4k page case, this is done just by reducing the size of the
RPN field to 39 bits, giving 51-bit real addresses.  In the 64k page
case, we had 10 unused bits in the middle of the PTE, so this moves
the RPN field down 10 bits to make use of those unused bits.  This
means the RPN field is now 3 bits larger at 37 bits, giving 53-bit
real addresses in the normal case, or 49-bit real addresses for the
special 4k PFN case.

We are doing this in order to be able to move some other PTE bits
into the positions where PowerISA V3.0 processors will expect to
find them in radix-tree mode.  Ultimately we will be able to move
the RPN field to lower bit positions and make it larger.
Signed-off-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

No code changes.
Signed-off-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

Pull in our current fixes from 4.5, in particular the "Fix Multi hit
ERAT" bug is causing folks some grief when testing next.

I ran into this issue while debugging an early boot problem. The system
hit a BUG_ON() but report bug failed to print the line number and file
name. The reason being that the system was running in real mode and
report_bug() searches for addresses in the PAGE_OFFSET+ region.
Suggested-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Balbir Singh <bsingharora@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

__xchg_called_with_bad_pointer() can't tell us which code uses {cmp}xchg
with an unsupported size, and no error is reported until the link stage.

To make such problems easier to debug, use BUILD_BUG_ON_MSG() instead.
Signed-off-by: pan xinhui <xinhui.pan@linux.vnet.ibm.com>
[mpe: Tweak change log wording & add relaxed/acquire]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

fixup

Most current OpenPOWER platforms have an AST BMC, so add graphics
support via the AST DRM driver.
Signed-off-by: Jeremy Kerr <jk@ozlabs.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

There are a few firmware-provided interfaces for OpenPOWER platforms:
the PRD infrastructure, IPMI support, and MTD access to the PNOR flash.

This change adds these to powernv_defconfig
Signed-off-by: Jeremy Kerr <jk@ozlabs.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

This change adds a defconfig for the non-virtualised power platforms,
based on pseries_defconfig, but without pseries, and little-endian,
and no OF trampoline.
Signed-off-by: Jeremy Kerr <jk@ozlabs.org>
Acked-by: Joel Stanley <joel@jms.id.au>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

Add a cputable entry for POWER9.  More code is required to actually
boot and run on a POWER9 but this gets the base piece in which we can
start building on.

Copies over from POWER8 except for:
- Adds a new CPU_FTR_ARCH_300 bit to start hanging new architecture
   features from (in subsequent patches).
- Advertises new user features bits PPC_FEATURE2_ARCH_3_00 &
  HAS_IEEE128 when on POWER9.
- Drops CPU_FTR_SUBCORE.
- Drops PMU code and machine check.
Signed-off-by: Michael Neuling <mikey@neuling.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

Use defines for literals __init_tlb_power[78] rather than hand coding
them.
Signed-off-by: Michael Neuling <mikey@neuling.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

Subcores isn't really part of the 2.07 architecture but currently we
turn it on using the 2.07 feature bit.  Subcores is really a POWER8
specific feature.

This adds a new CPU_FTR bit just for subcores and moves the subcore
init code over to use this.
Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Michael Neuling <mikey@neuling.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

When initialising OPAL interfaces, there is a possibility that
opal_msglog_init() may fail to initialise the msglog/memory console.

Fix opal_msglog_sysfs_init() so it doesn't try to create sysfs entry for
the msglog if this occurs.
Suggested-by: Joel Stanley <joel@jms.id.au>
Fixes: 9b4fffa1 ("powerpc/powernv: new function to access OPAL msglog")
Signed-off-by: Andrew Donnellan <andrew.donnellan@au1.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

We can get a hash pte fault with 4k base page size and find the pte
already inserted with 64K base page size. In that case we need to clear
the existing slot information from the old pte. Fix this correctly

With THP, we also clear the slot information with respect to all
the 64K hash pte mapping that 16MB page. They are all invalid
now. This make sure we don't find the slot valid when we fault with
4k base page size. Finding the slot valid should not result in any wrong
behavior because we do check again in hash page table for the validity.
But we can avoid that check completely.

Fixes: a43c0eb8 ("powerpc/mm: Convert 4k hash insert to C")
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

During error recovery, the device could be removed as part of the
partial hotplug. The criterion used to come with partial hotplug
is: if the device driver provides error_detected(), slot_reset()
and resume() callbacks, it's immune from hotplug. Otherwise,
it's going to experience partial hotplug during EEH recovery. But
the criterion isn't correct enough: mlx4_core driver for Mellanox
adapters provides error_detected(), slot_reset() callbacks, but
resume() isn't there. Those Mellanox adapters won't be to involved
in the partial hotplug.

This fixes the criterion to a practical one: adpater with driver
that provides error_detected(), slot_reset() will be immune from
partial hotplug. resume() isn't mandatory.

Fixes: f2da4ccf ("powerpc/eeh: More relaxed hotplug criterion")
Cc: stable@vger.kernel.org #v4.4+
Signed-off-by: Gavin Shan <gwshan@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

Implement cmpxchg{,64}_relaxed and atomic{,64}_cmpxchg_relaxed, based on
which _release variants can be built.

To avoid superfluous barriers in _acquire variants, we implement these
operations with assembly code rather use __atomic_op_acquire() to build
them automatically.

For the same reason, we keep the assembly implementation of fully
ordered cmpxchg operations.

However, we don't do the similar for _release, because that will require
putting barriers in the middle of ll/sc loops, which is probably a bad
idea.

Note cmpxchg{,64}_relaxed and atomic{,64}_cmpxchg_relaxed are not
compiler barriers.
Signed-off-by: Boqun Feng <boqun.feng@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

Implement xchg{,64}_relaxed and atomic{,64}_xchg_relaxed, based on these
_relaxed variants, release/acquire variants and fully ordered versions
can be built.

Note that xchg{,64}_relaxed and atomic_{,64}_xchg_relaxed are not
compiler barriers.
Signed-off-by: Boqun Feng <boqun.feng@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

On powerpc, acquire and release semantics can be achieved with
lightweight barriers("lwsync" and "ctrl+isync"), which can be used to
implement __atomic_op_{acquire,release}.

For release semantics, since we only need to ensure all memory accesses
that issue before must take effects before the -store- part of the
atomics, "lwsync" is what we only need. On the platform without
"lwsync", "sync" should be used. Therefore in __atomic_op_release() we
use PPC_RELEASE_BARRIER.

For acquire semantics, "lwsync" is what we only need for the similar
reason.  However on the platform without "lwsync", we can use "isync"
rather than "sync" as an acquire barrier. Therefore in
__atomic_op_acquire() we use PPC_ACQUIRE_BARRIER, which is barrier() on
UP, "lwsync" if available and "isync" otherwise.

Implement atomic{,64}_{add,sub,inc,dec}_return_relaxed, and build other
variants with these helpers.
Signed-off-by: Boqun Feng <boqun.feng@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

Some architectures may have their special barriers for acquire, release
and fence semantics, so that general memory barriers(smp_mb__*_atomic())
in the default __atomic_op_*() may be too strong, so allow architectures
to define their own helpers which can overwrite the default helpers.
Signed-off-by: Boqun Feng <boqun.feng@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

Enhanced Error Handling could mean anything in the context of the entire
kernel, so change the name to reference that it is both for PCI and
powerpc.

EEH covers a bit more than the previously listed files, so add the headers
and platform-specific code to the EEH maintained section.

In addition, I am taking over the maintainership.
Signed-off-by: Russell Currey <ruscur@russell.cc>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

I spent some time trying to use kgdb and debugged my inability to
resume from kgdb_handle_breakpoint(). NIP is not incremented
and that leads to a loop in the debugger.

I've tested this lightly on a virtual instance with KDB enabled.
After the patch, I am able to get the "go" command to work as
expected.
Signed-off-by: Balbir Singh <bsingharora@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

Quite often drivers set only "write" permission assuming that this
includes "read" permission as well and this works on plenty of
platforms. However IODA2 is strict about this and produces an EEH when
"read" permission is not set and reading happens.

This adds a workaround in the IODA code to always add the "read" bit
when the "write" bit is set.

Fixes: 10b35b2b ("powerpc/powernv: Do not set "read" flag if direction==DMA_NONE")
Cc: stable@vger.kernel.org # 4.2+
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Tested-by: Douglas Miller <dougmill@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

With ppc64 we use the deposited pgtable_t to store the hash pte slot
information. We should not withdraw the deposited pgtable_t without
marking the pmd none. This ensure that low level hash fault handling
will skip this huge pte and we will handle them at upper levels.

Recent change to pmd splitting changed the above in order to handle the
race between pmd split and exit_mmap. The race is explained below.

Consider following race:

		CPU0				CPU1
shrink_page_list()
  add_to_swap()
    split_huge_page_to_list()
      __split_huge_pmd_locked()
        pmdp_huge_clear_flush_notify()
	// pmd_none() == true
					exit_mmap()
					  unmap_vmas()
					    zap_pmd_range()
					      // no action on pmd since pmd_none() == true
	pmd_populate()

As result the THP will not be freed. The leak is detected by check_mm():

	BUG: Bad rss-counter state mm:ffff880058d2e580 idx:1 val:512

The above required us to not mark pmd none during a pmd split.

The fix for ppc is to clear the huge pte of _PAGE_USER, so that low
level fault handling code skip this pte. At higher level we do take ptl
lock. That should serialze us against the pmd split. Once the lock is
acquired we do check the pmd again using pmd_same. That should always
return false for us and hence we should retry the access. We do the
pmd_same check in all case after taking plt with
THP (do_huge_pmd_wp_page, do_huge_pmd_numa_page and
huge_pmd_set_accessed)

Also make sure we wait for irq disable section in other cpus to finish
before flipping a huge pte entry with a regular pmd entry. Code paths
like find_linux_pte_or_hugepte depend on irq disable to get
a stable pte_t pointer. A parallel thp split need to make sure we
don't convert a pmd pte to a regular pmd entry without waiting for the
irq disable section to finish.

Fixes: eef1b3ba ("thp: implement split_huge_pmd()")
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

When PCI bus is unplugged during full hotplug for EEH recovery,
the platform PE instance (struct pnv_ioda_pe) isn't released and
it dereferences the stale PCI bus that has been released. It leads
to kernel crash when referring to the stale PCI bus.

This fixes the issue by correcting the PE's primary bus when it's
oneline at plugging time, in pnv_pci_dma_bus_setup() which is to
be called by pcibios_fixup_bus().

Cc: stable@vger.kernel.org # v4.1+
Reported-by: Andrew Donnellan <andrew.donnellan@au1.ibm.com>
Reported-by: Pradipta Ghosh <pradghos@in.ibm.com>
Signed-off-by: Gavin Shan <gwshan@linux.vnet.ibm.com>
Tested-by: Andrew Donnellan <andrew.donnellan@au1.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

When PE is created, its primary bus is cached to pe->bus. At later
point, the cached primary bus is returned from eeh_pe_bus_get().
However, we could get stale cached primary bus and run into kernel
crash in one case: full hotplug as part of fenced PHB error recovery
releases all PCI busses under the PHB at unplugging time and recreate
them at plugging time. pe->bus is still dereferencing the PCI bus
that was released.

This adds another PE flag (EEH_PE_PRI_BUS) to represent the validity
of pe->bus. pe->bus is updated when its first child EEH device is
online and the flag is set. Before unplugging in full hotplug for
error recovery, the flag is cleared.

Fixes: 8cdb2833 ("powerpc/eeh: Trace PCI bus from PE")
Cc: stable@vger.kernel.org #v3.11+
Reported-by: Andrew Donnellan <andrew.donnellan@au1.ibm.com>
Reported-by: Pradipta Ghosh <pradghos@in.ibm.com>
Signed-off-by: Gavin Shan <gwshan@linux.vnet.ibm.com>
Tested-by: Andrew Donnellan <andrew.donnellan@au1.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

If a cpu is hotplugged while the hcall trace points are active, it's
possible to hit a warning from RCU due to the trace points calling into
RCU from an offline cpu, eg:

  RCU used illegally from offline CPU!
  rcu_scheduler_active = 1, debug_locks = 1

Make the hypervisor tracepoints conditional by using
TRACE_EVENT_FN_COND.
Acked-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Denis Kirjanov <kda@linux-powerpc.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

The GPCI hcall allows for a 4K buffer but we limit the buffer to 1K.
The problem with a 1K buffer is if a request results in returning
more values than can be accomodated in the 1K buffer the request will
fail.

The buffer we are using is currently allocated on the stack and hence
limited in size. Instead use a per-CPU 4K buffer like we do with 24x7
counters (hv-24x7.c).

While here, rename the macro GPCI_MAX_DATA_BYTES to HGPCI_MAX_DATA_BYTES
for consistency with 24x7 counters.
Signed-off-by: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

When M64 BAR is set to Single PE mode, the PE# assigned to VF could be
sparse.

This patch restructures the code to allocate sparse PE# for VFs when M64
BAR is set to Single PE mode. Also it rename the offset to pe_num_map to
reflect the content is the PE number.
Signed-off-by: Wei Yang <weiyang@linux.vnet.ibm.com>
Reviewed-by: Gavin Shan <gwshan@linux.vnet.ibm.com>
Acked-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

Each VF could have 6 BARs at most. When the total BAR size exceeds the
gate, after expanding it will also exhaust the M64 Window.

This patch limits the boundary by checking the total VF BAR size instead of
the individual BAR.
Signed-off-by: Wei Yang <weiyang@linux.vnet.ibm.com>
Reviewed-by: Gavin Shan <gwshan@linux.vnet.ibm.com>
Acked-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

At the moment 64bit-prefetchable window can be maximum 64GB, which is
currently got from device tree. This means that in shared mode the maximum
supported VF BAR size is 64GB/256=256MB. While this size could exhaust the
whole 64bit-prefetchable window. This is a design decision to set a
boundary to 64MB of the VF BAR size. Since VF BAR size with 64MB would
occupy a quarter of the 64bit-prefetchable window, this is affordable.

This patch replaces magic limit of 64MB with "gate", which is 1/4 of the
M64 Segment Size(m64_segsize >> 2) and adds comment to explain the reason
for it.
Signed-off-by: Wei Yang <weiyang@linux.vnet.ibm.com>
Reviewed-by: Gavin Shan <gwshan@linux.vent.ibm.com>
Acked-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

In current implementation, when VF BAR is bigger than 64MB, it uses 4 M64
BARs in Single PE mode to cover the number of VFs required to be enabled.
By doing so, several VFs would be in one VF Group and leads to interference
between VFs in the same group.

And in this patch, m64_wins is renamed to m64_map, which means index number
of the M64 BAR used to map the VF BAR. Based on Gavin's comments. Also
makes sure the VF BAR size is bigger than 32MB when M64 BAR is used in
Single PE mode.

This patch changes the design by using one M64 BAR in Single PE mode for
one VF BAR. This gives absolute isolation for VFs.
Signed-off-by: Wei Yang <weiyang@linux.vnet.ibm.com>
Reviewed-by: Gavin Shan <gwshan@linux.vnet.ibm.com>
Acked-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

The alignment of IOV BAR on PowerNV platform is the total size of the IOV
BAR. No matter whether the IOV BAR is extended with number of
roundup_pow_of_two(total_vfs) or number of max PE number (256), the total
size could be calculated by (vfs_expanded * VF_BAR_size).

This patch simplifies the pnv_pci_iov_resource_alignment() by removing the
first case.
Signed-off-by: Wei Yang <weiyang@linux.vnet.ibm.com>
Reviewed-by: Gavin Shan <gwshan@linux.vnet.ibm.com>
Acked-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

On PHB3, we enable SRIOV devices by mapping IOV BAR with M64 BARs. If a
SRIOV device's IOV BAR is not 64bit-prefetchable, this is not assigned from
64bit prefetchable window, which means M64 BAR can't work on it.

The reason is PCI bridges support only 2 memory windows and the kernel code
programs bridges in the way that one window is 32bit-nonprefetchable and
the other one is 64bit-prefetchable. So if devices' IOV BAR is 64bit and
non-prefetchable, it will be mapped into 32bit space and therefore M64
cannot be used for it.

This patch makes this explicit and truncate IOV resource in this case to
save MMIO space.
Signed-off-by: Wei Yang <weiyang@linux.vnet.ibm.com>
Reviewed-by: Gavin Shan <gwshan@linux.vnet.ibm.com>
Acked-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

The EEH debugfs handlers have same prototype. This introduces
a macro to define them, then to simplify the code. No logical
changes.
Signed-off-by: Gavin Shan <gwshan@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

Add 'P' command with optional task_struct address to dump all/one task's
information: task pointer, kernel stack pointer, PID, PPID, state
(interpreted), CPU where (last) running, and command.
Signed-off-by: Douglas Miller <dougmill@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>