selftests/powerpc: Use "Delta" rather than "Error" in normal output
Use "Delta" to refer to the difference between measurements, rather than
"Error", so scripts that look for "Error" aren't confused into thinking
there was a failure.
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
This patch adds an OPAL console backend to the powerpc boot wrapper so
that decompression failures inside the wrapper can be reported to the
user. This is important since it typically indicates data corruption in
the firmware and other nasty things.
Currently this only works when building a little endian kernel. When
compiling a 64 bit BE kernel the wrapper is always build 32 bit to be
compatible with some 32 bit firmwares. BE support will be added at a
later date. Another limitation of this is that only the "raw" type of
OPAL console is supported, however machines that provide a hvsi console
also provide a raw console so this is not an issue in practice.
Actually-written-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Oliver O'Halloran <oohall@gmail.com>
[mpe: Move #ifdef __powerpc64__ to avoid warnings on 32-bit] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
This patch adds the kernel command line parameter "no_tb_segs" which
forces the kernel to use 256MB rather than 1TB segments. Forcing the use
of 256MB segments makes it considerably easier to test code that depends
on an SLB miss occurring.
Suggested-by: Michael Neuling <mikey@neuling.org> Suggested-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Oliver O'Halloran <oohall@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Power ISAv3 adds a large decrementer (LD) mode which increases the size
of the decrementer register. The size of the enlarged decrementer
register is between 32 and 64 bits with the exact size being dependent
on the implementation. When in LD mode, reads are sign extended to 64
bits and a decrementer exception is raised when the high bit is set (i.e
the value goes below zero). Writes however are truncated to the physical
register width so some care needs to be taken to ensure that the high
bit is not set when reloading the decrementer. This patch adds support
for using the LD inside the host kernel on processors that support it.
When LD mode is supported firmware will supply the ibm,dec-bits property
for CPU nodes to allow the kernel to determine the maximum decrementer
value. Enabling LD mode is a hypervisor privileged operation so the kernel
can only enable it manually when running in hypervisor mode. Guests that
support LD mode can request it using the "ibm,client-architecture-support"
firmware call (not implemented in this patch) or some other platform
specific method. If this property is not supplied then the traditional
decrementer width of 32 bit is assumed and LD mode will not be enabled.
This patch was based on initial work by Jack Miller.
Signed-off-by: Oliver O'Halloran <oohall@gmail.com> Signed-off-by: Balbir Singh <bsingharora@gmail.com> Acked-by: Michael Neuling <mikey@neuling.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
powerpc/pseries: Fix error return value in cmm_mem_going_offline()
cmm_mem_going_offline() is (only) called from cmm_memory_cb(), which
sends the return value through notifier_from_errno(). The latter
expects 0 or -errno (notifier_to_errno(notifier_from_errno(x)) is 0
for any x >= 0, so passing a positive value cannot make sense). Hence
negate ENOMEM.
Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Andrew Donnellan [Fri, 18 Mar 2016 06:36:33 +0000 (17:36 +1100)]
powerpc/rtas: Fix array overrun in ppc_rtas() syscall
If ppc_rtas() is called with args.nargs == 16 and args.nret == 0,
args.rets is set to point to &args.args[16], which is beyond the end of
the args.args array. This results in a minor read overrun of the array
when we check the first return code (which, per PAPR, is a required
output of all RTAS calls) to see if there's been a hardware error.
Change the nargs/nret check to ensure nargs is <= 15, allowing room for
the status code. Users shouldn't be calling with nret == 0, but there's
no real harm if they do, so we don't stop them.
Signed-off-by: Andrew Donnellan <andrew.donnellan@au1.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Chris Smart [Thu, 16 Jun 2016 23:33:45 +0000 (09:33 +1000)]
powerpc: Send SIGBUS on unaligned copy and paste
Calling ISA 3.0 instructions copy, copy_first, paste and paste_last
generates an alignment fault when copying or pasting unaligned
data (128 byte). We catch this and send SIGBUS to the userspace
process that caused it.
We do not emulate these because paste may contain additional metadata
when pasting to a co-processor and paste_last is the synchronisation
point for preceding copy/paste sequences.
Thanks to Michael Neuling <mikey@neuling.org> for his help.
Signed-off-by: Chris Smart <chris@distroguy.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Cyril Bur [Thu, 3 Mar 2016 23:06:40 +0000 (10:06 +1100)]
selftests/powerpc: Fix generation of vector instructions/types in context_switch
Currently it doesn't appear the resulting binary actually uses any
Altivec or VSX instructions the solution is to explicitly tell GCC to
use vector instructions and use vector types in the code.
Part of this this issue can be GCC version specific:
GCC 4.9.x is happy to use Altivec and VSX instructions if altivec.h is
includedi (and possibly if vector types are used), this also means that
4.9.x will use VSX instructions even if only -maltivec is passed. It is
also possible that Altivec instructions will be used even without
-maltivec or -mabi=altivec.
GCC 5.2.x complains about the lack of -maltivec parameter if altivec.h
is included and will not use VSX unless -mvsx is present on commandline.
GCC 5.3.0 has a regression that means __attribute__((__target__("no-vsx"))
fails to build. A fix is targeted for 5.4.
Furthermore LTO (Link Time Optimisation) doesn't play well with
__attribute__((__target__("no-vsx")), LTO can cause GCC to forget about
the attribute and compile with VSX instructions regardless. Be wary when
enabling -flfo for this test.
Signed-off-by: Cyril Bur <cyrilbur@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Cyril Bur [Tue, 1 Mar 2016 04:26:36 +0000 (15:26 +1100)]
selftests/powerpc/pmu: Use signed long to read perf_event_paranoid
Excerpt from man 2 perf_event_open:
/proc/sys/kernel/perf_event_paranoid
The perf_event_paranoid file can be set to restrict access to the
performance counters.
2 allow only user-space measurements.
1 allow both kernel and user measurements (default).
0 allow access to CPU-specific data but not raw tracepoint samples.
-1 no restrictions.
require_paranoia_below() should return 0 if perf_event_paranoid is below
a specified level, the value from perf_event_paranoid is read into an
unsigned long so the incorrect value is returned when
perf_event_paranoid is set to -1.
Without this patch applied there is the same number of selftests/powerpc
which skip when /proc/sys/kernel/perf_event_paranoid is set to 1 or -1
but no skips when set to zero.
With this patch applied there are no skipped selftests/powerpc test when
/proc/sys/kernel/perf_event_paranoid is set to 0 or -1.
Signed-off-by: Cyril Bur <cyrilbur@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Factor out the power8 pmu init functions to share with
power9. Monitor Mode Control Register S(MMCRS) and
Monitor Mode Control Register H(MMCRH) registers are
dropped in Power9. These registers are added to new
function which are included for power8 init.
Signed-off-by: Madhavan Srinivasan <maddy@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
powerpc/fadump: Fix build error introduced by recent cleanup
We spent so much time bike-shedding the printk() we missed that the next
line was missing a semi-colon. And it seems none of our defconfigs turn
on CONFIG_FA_DUMP.
Fixes: 4a03749f140c ("powerpc/fadump: Trivial fix of spelling mistake, clean up message") Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
powerpc/powernv: Add driver for operator panel on FSP machines
Implement new character device driver to allow access from user space
to the operator panel display present on IBM Power Systems machines
with FSPs.
This will allow status information to be presented on the display which
is visible to a user.
The driver implements a character buffer which a user can read/write
by accessing the device (/dev/op_panel). This buffer is then displayed on
the operator panel display. Any attempt to write past the last character
position will have no effect and attempts to write more characters than
the size of the display will be truncated. The device may only be accessed
by a single process at a time.
Signed-off-by: Suraj Jitindar Singh <sjitindarsingh@gmail.com> Reviewed-by: Andrew Donnellan <andrew.donnellan@au1.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
powerpc/opal: Add inline function to get rc from an ASYNC_COMP opal_msg
An opal_msg of type OPAL_MSG_ASYNC_COMP contains the return code in the
params[1] struct member. However this isn't intuitive or obvious when
reading the code and requires that a user look at the skiboot
documentation or opal-api.h to verify this.
Add an inline function to get the return code from an opal_msg and update
call sites accordingly.
Signed-off-by: Suraj Jitindar Singh <sjitindarsingh@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
devicetree/bindings: Add binding for operator panel on FSP machines
Add a binding to Documentation/devicetree/bindings/powerpc/opal
(oppanel-opal.txt) for the operator panel which is present on IBM
Power Systems machines with FSPs.
Signed-off-by: Suraj Jitindar Singh <sjitindarsingh@gmail.com> Acked-by: Rob Herring <robh@kernel.org> Acked-by: Stewart Smith <stewart@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Michael Neuling [Fri, 24 Jun 2016 06:47:07 +0000 (08:47 +0200)]
cxl: Add set and get private data to context struct
This provides AFU drivers a means to associate private data with a cxl
context. This is particularly intended for make the new callbacks for
driver specific events easier for AFU drivers to use, as they can easily
get back to any private data structures they may use.
Signed-off-by: Michael Neuling <mikey@neuling.org> Signed-off-by: Ian Munsie <imunsie@au1.ibm.com> Signed-off-by: Philippe Bergheaud <felix@linux.vnet.ibm.com Reviewed-by: Matthew R. Ochs <mrochs@linux.vnet.ibm.com> Reviewed-by: Andrew Donnellan <andrew.donnellan@au1.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
cxl: Add mechanism for delivering AFU driver specific events
This adds an afu_driver_ops structure with fetch_event() and
event_delivered() callbacks. An AFU driver such as cxlflash can fill
this out and associate it with a context to enable passing custom AFU
specific events to userspace.
This also adds a new kernel API function cxl_context_pending_events(),
that the AFU driver can use to notify the cxl driver that new specific
events are ready to be delivered, and wake up anyone waiting on the
context wait queue.
The current count of AFU driver specific events is stored in the field
afu_driver_events of the context structure.
The cxl driver checks the afu_driver_events count during poll, select,
read, etc. calls to check if an AFU driver specific event is pending,
and calls fetch_event() to obtain and deliver that event. This way, the
cxl driver takes care of all the usual locking semantics around these
calls and handles all the generic cxl events, so that the AFU driver
only needs to worry about it's own events.
fetch_event() return a struct cxl_event_afu_driver_reserved, allocated
by the AFU driver, and filled in with the specific event information and
size. Total event size (header + data) should not be greater than
CXL_READ_MIN_SIZE (4K).
Th cxl driver prepends an appropriate cxl event header, copies the event
to userspace, and finally calls event_delivered() to return the status of
the operation to the AFU driver. The event is identified by the context
and cxl_event_afu_driver_reserved pointers.
Since AFU drivers provide their own means for userspace to obtain the
AFU file descriptor (i.e. cxlflash uses an ioctl on their scsi file
descriptor to obtain the AFU file descriptor) and the generic cxl driver
will never use this event, the ABI of the event is up to each individual
AFU driver.
Signed-off-by: Philippe Bergheaud <felix@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Colin Ian King [Mon, 27 Jun 2016 11:07:41 +0000 (12:07 +0100)]
powerpc/fadump: Trivial fix of spelling mistake, clean up message
Fix trivial spelling mistake "rgistration". Also use pr_err()
instead of printk() and unsplit the string to keep it all on one
line.
Signed-off-by: Colin Ian King <colin.king@canonical.com>
[mpe: Keep rc on the same line, splitting it doesn't help] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
powerpc/pci: Reduce log level of PCI I/O space warning
If a PHB has no I/O space, there's no need to make it look like
something bad happened, a pr_debug() is plenty enough since this
is the case of all our modern POWER chips.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Naveen N. Rao [Wed, 22 Jun 2016 16:25:06 +0000 (21:55 +0530)]
powerpc/bpf/jit: Isolate classic BPF JIT specifics into a separate header
Break out classic BPF JIT specifics into a separate header in
preparation for eBPF JIT implementation. Note that ppc32 will still need
the classic BPF JIT.
Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Naveen N. Rao [Wed, 22 Jun 2016 16:25:05 +0000 (21:55 +0530)]
powerpc/bpf/jit: A few cleanups
1. Per the ISA, ADDIS actually uses RT, rather than RS. Though
the result is the same, make the usage clear.
2. The multiply instruction used is a 32-bit multiply. Rename PPC_MUL()
to PPC_MULW() to make the same clear.
3. PPC_STW[U] take the entire 16-bit immediate value and do not require
word-alignment, per the ISA. Change the macros to use IMM_L().
4. A few white-space cleanups to satisfy checkpatch.pl.
Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Since we will be using the rotate immediate instructions for extended
BPF JIT, let's introduce macros for the same. And since the shift
immediate operations use the rotate immediate instructions, let's redo
those macros to use the newly introduced instructions.
Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Naveen N. Rao [Wed, 22 Jun 2016 16:25:03 +0000 (21:55 +0530)]
powerpc/bpf/jit: Optimize 64-bit Immediate loads
Similar to the LI32() optimization, if the value can be represented
in 32-bits, use LI32(). Also handle loading a few specific forms of
immediate values in an optimum manner.
Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
The existing LI32() macro can sometimes result in a sign-extended 32-bit
load that does not clear the top 32-bits properly. As an example,
loading 0x7fffffff results in the register containing
0xffffffff7fffffff. While this does not impact classic BPF JIT
implementation (since that only uses the lower word for all operations),
we would like to share this macro between classic BPF JIT and extended
BPF JIT, wherein the entire 64-bit value in the register matters. Fix
this by first doing a shifted LI followed by ORI.
An additional optimization is with loading values between -32768 to -1,
where we now only need a single LI.
The new implementation now generates the same or less number of
instructions.
Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
powerpc/powernv: set power_save func after the idle states are initialized
pnv_init_idle_states() discovers supported idle states from the
device tree and does the required initialization. Set power_save
function pointer only after this initialization is done
Otherwise on machines which don't support nap, eg. Power9, the kernel
will crash when it tries to nap.
Reviewed-by: Gautham R. Shenoy <ego@linux.vnet.ibm.com> Signed-off-by: Shreyas B. Prabhu <shreyas@linux.vnet.ibm.com> Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Acked-by: Michael Neuling <mikey@neuling.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Gavin Shan [Fri, 20 May 2016 06:41:42 +0000 (16:41 +1000)]
PCI/hotplug: PowerPC PowerNV PCI hotplug driver
This adds standalone driver to support PCI hotplug for PowerPC PowerNV
platform that runs on top of skiboot firmware. The firmware identifies
hotpluggable slots and marked their device tree node with proper
"ibm,slot-pluggable" and "ibm,reset-by-firmware". The driver scans
device tree nodes to create/register PCI hotplug slot accordingly.
The PCI slots are organized in fashion of tree, which means one
PCI slot might have parent PCI slot and parent PCI slot possibly
contains multiple child PCI slots. At the plugging time, the parent
PCI slot is populated before its children. The child PCI slots are
removed before their parent PCI slot can be removed from the system.
If the skiboot firmware doesn't support slot status retrieval, the PCI
slot device node shouldn't have property "ibm,reset-by-firmware". In
that case, none of valid PCI slots will be detected from device tree.
The skiboot firmware doesn't export the capability to access attention
LEDs yet and it's something for TBD.
Gavin Shan [Fri, 20 May 2016 06:41:41 +0000 (16:41 +1000)]
powerpc/powernv: Functions to get/set PCI slot state
This exports 4 functions, which base on the corresponding OPAL
APIs to get/set PCI slot status. Those functions are going to
be used by PowerNV PCI hotplug driver:
Gavin Shan [Fri, 20 May 2016 06:41:39 +0000 (16:41 +1000)]
powerpc/powernv: Use PCI slot reset infrastructure
The (OPAL) firmware might provide the PCI slot reset capability
which is identified by property "ibm,reset-by-firmware" on the
PCI slot associated device node.
This routes the reset request to firmware if "ibm,reset-by-firmware"
exists in the PCI slot device node. Otherwise, the reset is done
inside kernel as before.
Signed-off-by: Gavin Shan <gwshan@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Gavin Shan [Fri, 20 May 2016 06:41:38 +0000 (16:41 +1000)]
powerpc/powernv: Support PCI slot ID
The reset and poll functionality from (OPAL) firmware supports
PHB and PCI slot at same time. They are identified by ID. This
supports PCI slot ID by:
* Rename the argument name for opal_pci_reset() and opal_pci_poll()
accordingly
* Rename pnv_eeh_phb_poll() to pnv_eeh_poll() and adjust its argument
name.
* One macro is added to produce PCI slot ID.
Signed-off-by: Gavin Shan <gwshan@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Gavin Shan [Fri, 20 May 2016 06:41:37 +0000 (16:41 +1000)]
powerpc/pci: Delay populating pdn
The pdn (struct pci_dn) instances are allocated from memblock or
bootmem when creating PCI controller (hoses) in setup_arch(). PCI
hotplug, which will be supported by proceeding patches, releases
PCI device nodes and their corresponding pdn on unplugging event.
The memory chunks for pdn instances allocated from memblock or
bootmem are hard to reused after being released.
This delays creating pdn by pci_devs_phb_init() from setup_arch()
to core_initcall() so that they are allocated from slab. The memory
consumed by pdn can be released to system without problem during
PCI unplugging time. It indicates that pci_dn is unavailable in
setup_arch() and the the fixup on pdn (like AGP's) can't be carried
out that time. We have to do that in pcibios_root_bridge_prepare()
on maple/pasemi/powermac platforms where/when the pdn is available.
pcibios_root_bridge_prepare is called from subsys_initcall() which
is executed after core_initcall() so the code flow does not change.
At the mean while, the EEH device is created when pdn is populated,
meaning pdn and EEH device have same life cycle. In turn, we needn't
call eeh_dev_init() to create EEH device explicitly.
Gavin Shan [Fri, 20 May 2016 06:41:36 +0000 (16:41 +1000)]
powerpc/pci: Update bridge windows on PCI plug
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.
Gavin Shan [Fri, 20 May 2016 06:41:35 +0000 (16:41 +1000)]
powerpc/powernv: Dynamically release PE
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:
Gavin Shan [Fri, 20 May 2016 06:41:34 +0000 (16:41 +1000)]
powerpc/powernv: Make pnv_ioda_deconfigure_pe() visible
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>
Gavin Shan [Fri, 20 May 2016 06:41:33 +0000 (16:41 +1000)]
powerpc/powernv: Extend PCI bridge resources
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>
Gavin Shan [Fri, 20 May 2016 06:41:32 +0000 (16:41 +1000)]
powerpc/powernv: Setup PE for root bus
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>
Gavin Shan [Fri, 20 May 2016 06:41:31 +0000 (16:41 +1000)]
powerpc/powernv: Create PEs in pcibios_setup_bridge()
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>
Gavin Shan [Fri, 20 May 2016 06:41:30 +0000 (16:41 +1000)]
powerpc/powernv: Allocate PE# in reverse order
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.
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>
Gavin Shan [Fri, 20 May 2016 06:41:29 +0000 (16:41 +1000)]
powerpc/powernv: Increase PE# capacity
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>
Gavin Shan [Fri, 20 May 2016 06:41:28 +0000 (16:41 +1000)]
powerpc/powernv: Move pnv_pci_ioda_setup_opal_tce_kill() around
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.
Gavin Shan [Fri, 20 May 2016 06:41:26 +0000 (16:41 +1000)]
powerpc/pci: Override pcibios_setup_bridge()
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.
Gavin Shan [Fri, 20 May 2016 06:41:25 +0000 (16:41 +1000)]
PCI: Add pcibios_setup_bridge()
Currently, PowerPC PowerNV platform utilizes ppc_md.pcibios_fixup(),
which is called for once after PCI probing and resource assignment
are completed, to allocate platform required resources for PCI devices:
PE#, IO and MMIO mapping, DMA address translation (TCE) table etc.
Obviously, it's not hotplug friendly.
This adds weak function pcibios_setup_bridge(), which is called by
pci_setup_bridge(). PowerPC PowerNV platform will reuse the function
to assign above platform required resources to newly plugged PCI devices
during PCI hotplug in subsequent patches.
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:
Jack Miller [Thu, 9 Jun 2016 02:31:10 +0000 (12:31 +1000)]
selftests/powerpc: Load Monitor Register Tests
Adds two tests. One is a simple test to ensure that the new registers
LMRR and LMSER are properly maintained. The other actually uses the
existing EBB test infrastructure to test that LMRR and LMSER behave as
documented.
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>
Jack Miller [Thu, 9 Jun 2016 02:31:09 +0000 (12:31 +1000)]
powerpc: Load Monitor Register Support
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>
Michael Neuling [Thu, 9 Jun 2016 02:31:08 +0000 (12:31 +1000)]
powerpc: Improve FSCR init and context switching
This fixes a few issues with FSCR init and switching.
In commit 152d523e6307 ("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>
powerpc: Fix misleading comment in early_setup_secondary()
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>
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 c1c355ce14c0 ("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>
Russell Currey [Fri, 17 Jun 2016 05:25:17 +0000 (15:25 +1000)]
powerpc/pci: Fix SRIOV not building without EEH enabled
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>
Frederic Barrat [Wed, 15 Jun 2016 14:42:16 +0000 (16:42 +0200)]
cxl: Make vPHB device node match adapter's
On bare-metal, when a device is attached to the cxl card, lsvpd shows
a location code such as (with cxlflash):
# lsvpd -l sg22
...
*YL U78CB.001.WZS0073-P1-C33-B0-T0-L0
which makes it hard to easily identify the cxl adapter owning the
flash device, since in this example C33 refers to a P8 processor.
lsvpd looks in the parent devices until it finds a location code, so the
device node for the vPHB ends up being used.
By reusing the device node of the adapter for the vPHB, lsvpd shows:
# lsvpd -l sg16
...
*YL U78C9.001.WZS09XA-P1-C7-B1-T0-L3
where C7 is the PCI slot of the cxl adapter.
On powerVM, the vPHB was already using the adapter device node, so
there's no change there.
Tested by cxlflash on bare-metal and powerVM.
Signed-off-by: Frederic Barrat <fbarrat@linux.vnet.ibm.com> Reviewed-by: Matthew R. Ochs <mrochs@linux.vnet.ibm.com> Acked-by: Ian Munsie <imunsie@au1.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Ian Munsie [Wed, 8 Jun 2016 05:09:54 +0000 (15:09 +1000)]
cxl: Add support for CAPP DMA mode
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>
Frederic Barrat [Mon, 23 May 2016 17:39:18 +0000 (03:39 +1000)]
cxl: Abstract the differences between the PSL and XSL
The XSL (Translation Service Layer) is a stripped down version of the
PSL (Power Service Layer) used in some cards such as the Mellanox CX4.
Like the PSL, it implements the CAIA architecture, but has a number of
differences, mostly in it's implementation dependent registers. This
adds an ops structure to abstract these differences to bring initial
support for XSL CAPI devices.
The XSL does not implement the optional architected SERR register,
however while it treats it as a reserved register and should work with
no special treatment, attempting to access it will cause the XSL_FEC
(First Error Capture) register to be filled out, preventing it from
capturing any subsequent errors. Therefore, this patch also prevents the
kernel from trying to set up the SERR register so that the FEC register
may still be useful, and to save one interrupt.
The XSL also uses a special DMA cxl mode, which uses a slightly
different init sequence for the CAPP and PHB. The kernel support for
this will be in a future patch once the corresponding support has been
merged into skiboot.
Co-authored-by: Ian Munsie <imunsie@au1.ibm.com> Signed-off-by: Ian Munsie <imunsie@au1.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Ian Munsie [Mon, 23 May 2016 16:14:05 +0000 (02:14 +1000)]
cxl: Update process element after allocating interrupts
In the kernel API, it is possible to attempt to allocate AFU interrupts
after already starting a context. Since the process element structure
used by the hardware is only filled out at the time the context is
started, it will not be updated with the interrupt numbers that have
just been allocated and therefore AFU interrupts will not work unless
they were allocated prior to starting the context.
This can present some difficulties as each CAPI enabled PCI device in
the kernel API has a default context, which may need to be started very
early to enable translations, potentially before interrupts can easily
be set up.
This patch makes the API more flexible to allow interrupts to be
allocated after a context has already been started and takes care of
updating the PE structure used by the hardware and notifying it to
discard any cached copy it may have.
The update is currently performed via a terminate/remove/add sequence.
This is necessary on some hardware such as the XSL that does not
properly support the update LLCMD.
Note that this is only supported on powernv at present - attempting to
perform this ordering on PowerVM will raise a warning.
Signed-off-by: Ian Munsie <imunsie@au1.ibm.com> Reviewed-by: Frederic Barrat <fbarrat@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Andrew Donnellan [Mon, 18 Apr 2016 05:03:50 +0000 (15:03 +1000)]
cxl: static-ify variables to fix sparse warnings
Make a couple more variables static. Found by sparse.
Signed-off-by: Andrew Donnellan <andrew.donnellan@au1.ibm.com> Reviewed-by: fbarrat@linux.vnet.ibm.com Reviewed-by: Matthew R. Ochs <mrochs@linux.vnet.ibm.com> Acked-by: Ian Munsie <imunsie@au1.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
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>
Daniel Axtens [Wed, 18 May 2016 01:16:50 +0000 (11:16 +1000)]
powerpc: Introduce asm-prototypes.h
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>
powerpc: Add array bounds checking to crash_shutdown_handlers
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>
Rashmica Gupta [Wed, 1 Jun 2016 22:56:47 +0000 (08:56 +1000)]
powerpc/asm: Remove unused symbols in asm-offsets.c
THREAD_DSCR:
Added in efcac6589a27 "powerpc: Per process DSCR + some fixes (try#4)"
Last usage removed in 152d523e6307 "powerpc: Create context switch helpers save_sprs() and restore_sprs()"
THREAD_DSCR_INHERIT:
Added in 714332858bfd "powerpc: Restore correct DSCR in context switch"
Last usage removed in 152d523e6307 "powerpc: Create context switch helpers save_sprs() and restore_sprs()"
THREAD_TAR:
Added in 2468dcf641e4 "powerpc: Add support for context switching the TAR register"
Last usage removed in 152d523e6307 "powerpc: Create context switch helpers save_sprs() and restore_sprs()"
THREAD_BESCR, THREAD_EBBHR and THREAD_EBBRR:
Added in 9353374b8e15 "powerpc: Context switch the new EBB SPRs"
Last usage removed in 152d523e6307 "powerpc: Create context switch helpers save_sprs() and restore_sprs()"
THREAD_SIAR, THREAD_SDAR, THREAD_SIER, THREAD_MMCR0, and THREAD_MMCR2:
Added in 59affcd3e460 "powerpc: Context switch more PMU related SPRs"
Last usage removed in b11ae95100f7 "powerpc: Partial revert of "Context switch more PMU related SPRs""
PACA_LOCK_TOKEN:
Added in 9e368f291560 "KVM: PPC: book3s_hv: Add support for PPC970-family processors"
Last usage removed in c17b98cf6028 "KVM: PPC: Book3S HV: Remove code for PPC970 processors"
HCALL_STAT_SIZE, HCALL_STAT_CALLS, HCALL_STAT_TB and HCALL_STAT_PURR:
Added in 57852a853b0d "[POWERPC] powerpc: Instrument Hypervisor Calls"
Last usage removed in c8cd093a6e9f "powerpc: tracing: Add hypervisor call tracepoints"
VCPU_EPLC:
Added in d30f6e480055 "KVM: PPC: booke: category E.HV (GS-mode) support"
Never used.
CPU_DOWN_FLUSH:
Added in e7affb1dba0e "powerpc/cache: add cache flush operation for various e500"
Never used.
CFG_STAMP_XSEC:
Added in 14cf11af6cf6 "powerpc: Merge enough to start building in arch/powerpc."
Last usage removed in 0e469db8f70c "powerpc: Rework VDSO gettimeofday to prevent time going backwards"
KVM_LPCR:
Added in aa04b4cc5be6 "KVM: PPC: Allocate RMAs (Real Mode Areas) at boot for use by guests"
Last usage removed in a0144e2a6b0b "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 14cf11af6cf6 "powerpc: Merge enough to start building in arch/powerpc."
Never used.
VCPU_SHADOW_FSCR:
Added in 616dff860282 "KVM: PPC: Book3S PR: Handle Facility interrupt and FSCR"
Never used.
VCPU_SHADOW_SRR1:
Added in a2d56020d1d9 "KVM: PPC: Book3S PR: Keep volatile reg values in vcpu rather than shadow_vcpu"
Never used.
KVM_SPLIT_SIZE:
Added in b4deba5c41e9 "KVM: PPC: Book3S HV: Implement dynamicmicro-threading on POWER8"
Never used.
VCPU_VCPUID:
Added in de56a948b918 "KVM: PPC: Add support for Book3S processors in hypervisor mode"
Last usage removed 1b400ba0cd24 "KVM: PPC: Book3S HV: Improve handling of local vs. global TLB invalidations"
_MQ:
Added in 14cf11af6cf6 "powerpc: Merge enough to start building in arch/powerpc."
Never used.
AUDITCONTEXT:
Added in 14cf11af6cf6 "powerpc: Merge enough to start building in arch/powerpc."
Last usage removed in 401d1f029beb "[PATCH] syscall entry/exit revamp"
CLONE_VM:
Added in 14cf11af6cf6 "powerpc: Merge enough to start building in arch/powerpc."
Currently unused.
CLONE_UNTRACED:
Added in 14cf11af6cf6 "powerpc: Merge enough to start building in arch/powerpc."
Currently unused.
Bharata B Rao [Thu, 12 May 2016 13:34:15 +0000 (19:04 +0530)]
powerpc/numa: Fix multiple bugs in memory_hotplug_max()
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: cd34206e949b ("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>
Bharata B Rao [Thu, 12 May 2016 13:34:14 +0000 (19:04 +0530)]
powerpc/numa: Fix whitespace in hot_add_drconf_memory_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>
Boqun Feng [Fri, 10 Jun 2016 03:51:28 +0000 (11:51 +0800)]
powerpc/spinlock: Fix spin_unlock_wait()
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:
d86b8da04dfa ("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:
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>
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>
Rashmica Gupta [Mon, 30 May 2016 06:18:15 +0000 (16:18 +1000)]
powerpc/pseries: Remove MPIC from pseries event sources
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>
Rashmica Gupta [Mon, 30 May 2016 06:18:13 +0000 (16:18 +1000)]
powerpc/pseries: Remove MPIC from pseries kexec
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>
Rashmica Gupta [Mon, 30 May 2016 06:18:12 +0000 (16:18 +1000)]
powerpc/pseries: Remove MPIC from pseries smp
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>
Rashmica Gupta [Mon, 30 May 2016 06:18:11 +0000 (16:18 +1000)]
powerpc/pseries: Drop support for MPIC in pseries
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>
Anton Blanchard [Wed, 25 May 2016 22:38:13 +0000 (08:38 +1000)]
powerpc: Remove assembly versions of strcpy, strcat, strlen and strcmp
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>
Anton Blanchard [Sun, 29 May 2016 12:03:51 +0000 (22:03 +1000)]
powerpc: Avoid load hit store in setup_sigcontext()
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>
Anton Blanchard [Sun, 29 May 2016 12:03:50 +0000 (22:03 +1000)]
powerpc: Avoid load hit store in __giveup_fpu() and __giveup_altivec()
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:
Linus Torvalds [Sun, 12 Jun 2016 13:30:39 +0000 (06:30 -0700)]
Merge branch 'for-rc' of git://git.kernel.org/pub/scm/linux/kernel/git/rzhang/linux
Pull thermal management fixes from Zhang Rui:
- fix an ordering issue in cpu cooling that cooling device is
registered before it's ready (freq_table being populated).
(Lukasz Luba)
- fix a missing comment update (Caesar Wang)
* 'for-rc' of git://git.kernel.org/pub/scm/linux/kernel/git/rzhang/linux:
thermal: add the note for set_trip_temp
thermal: cpu_cooling: fix improper order during initialization
Linus Torvalds [Sun, 12 Jun 2016 01:42:59 +0000 (18:42 -0700)]
Merge branch 'for-linus' of git://git.kernel.dk/linux-block
Pull block layer fixes from Jens Axboe:
"A small collection of fixes for the current series. This contains:
- Two fixes for xen-blkfront, from Bob Liu.
- A bug fix for NVMe, releasing only the specific resources we
requested.
- Fix for a debugfs flags entry for nbd, from Josef.
- Plug fix from Omar, fixing up a case of code being switched between
two functions.
- A missing bio_put() for the new discard callers of
submit_bio_wait(), fixing a regression causing a leak of the bio.
From Shaun.
- Improve dirty limit calculation precision in the writeback code,
fixing a case where setting a limit lower than 1% of memory would
end up being zero. From Tejun"
* 'for-linus' of git://git.kernel.dk/linux-block:
NVMe: Only release requested regions
xen-blkfront: fix resume issues after a migration
xen-blkfront: don't call talk_to_blkback when already connected to blkback
nbd: pass the nbd pointer for flags debugfs
block: missing bio_put following submit_bio_wait
blk-mq: really fix plug list flushing for nomerge queues
writeback: use higher precision calculation in domain_dirty_limits()
Linus Torvalds [Sun, 12 Jun 2016 01:03:39 +0000 (18:03 -0700)]
Merge tag 'gpio-v4.7-3' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-gpio
Pull GPIO fixes from Linus Walleij:
"A new bunch of GPIO fixes for v4.7.
This time I am very grateful that Ricardo Ribalda Delgado went in and
fixed my stupid refcounting mistakes in the removal path for GPIO
chips. I had a feeling something was wrong here and so it was. It
exploded on OMAP and it fixes their problem. Now it should be (more)
solid.
The rest i compilation, Kconfig and driver fixes. Some tagged for
stable.
Summary:
- Fix a NULL pointer dereference when we are searching the GPIO
device list but one of the devices have been removed (struct
gpio_chip pointer is NULL).
- Fix unaligned reference counters: we were ending on +3 after all
said and done. It should be 0. Remove an extraneous get_device(),
and call cdev_del() followed by device_del() in gpiochip_remove()
instead and the count goes to zero and calls the release() function
properly.
- Fix a compile warning due to a missing #include in the OF/device
tree portions.
- Select ANON_INODES for GPIOLIB, we're using that for our character
device. Some randconfig tests disclosed the problem.
- Make sure the Zynq driver clock runs also without CONFIG_PM enabled
- Fix an off-by-one error in the 104-DIO-48E driver
- Fix warnings in bcm_kona_gpio_reset()"
* tag 'gpio-v4.7-3' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-gpio:
gpio: bcm-kona: fix bcm_kona_gpio_reset() warnings
gpio: select ANON_INODES
gpio: include <linux/io-mapping.h> in gpiolib-of
gpiolib: Fix unaligned used of reference counters
gpiolib: Fix NULL pointer deference
gpio: zynq: initialize clock even without CONFIG_PM
gpio: 104-dio-48e: Fix control port offset computation off-by-one error
Linus Torvalds [Sat, 11 Jun 2016 18:42:08 +0000 (11:42 -0700)]
Merge tag 'scsi-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi
Pull SCSI fixes from James Bottomley:
"Two current fixes:
- one affects Qemu CD ROM emulation, which stopped working after the
updates in SCSI to require VPD pages from all conformant devices.
Fix temporarily by blacklisting Qemu (we can relax later when they
come into compliance).
- The other is a fix to the optimal transfer size. We set up a
minefield for ourselves by being confused about whether the limits
are in bytes or sectors (SCSI optimal is in blocks and the queue
parameter is in bytes).
This tries to fix the problem (wrong setting for queue limits
max_sectors) and make the problem more obvious by introducing a
wrapper function"
* tag 'scsi-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi:
sd: Fix rw_max for devices that report an optimal xfer size
scsi: Add QEMU CD-ROM to VPD Inquiry Blacklist
Linus Torvalds [Sat, 11 Jun 2016 18:24:54 +0000 (11:24 -0700)]
Merge branch 'i2c/for-current' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux
Pull i2c fixes from Wolfram Sang:
- a bigger fix for i801 to finally be able to be loaded on some
machines again
- smaller driver fixes
- documentation update because of a renamed file
* 'i2c/for-current' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux:
i2c: mux: reg: Provide of_match_table
i2c: mux: refer to i2c-mux.txt
i2c: octeon: Avoid printk after too long SMBUS message
i2c: octeon: Missing AAK flag in case of I2C_M_RECV_LEN
i2c: i801: Allow ACPI SystemIO OpRegion to conflict with PCI BAR
Linus Torvalds [Sat, 11 Jun 2016 17:55:30 +0000 (10:55 -0700)]
Merge tag '20160610_uvc_compat_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/luto/linux
Pull uvc compat XU ioctl fixes from Andy Lutomirski:
"uvc's compat XU ioctls go through tons of potentially buggy
indirection. The first patch removes the indirection. The second one
cleans up the code.
Compile-tested only. I have the hardware, but I have absolutely no
idea what XU does, how to use it, what software to recompile as
32-bit, or what to test in that software"
* tag '20160610_uvc_compat_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/luto/linux:
uvc_v4l2: Simplify compat ioctl implementation
uvc: Forward compat ioctls to their handlers directly
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