The spec says it "may be problematic" if CPU x registers the VPA of
CPU y. Add a warning in case we ever do that.
Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
As a part of pseries_idle backend driver cleanup to make
the code common to both pseries and powernv platforms, it
is necessary to move the backend-driver code to drivers/cpuidle.
As a pre-requisite for that, it is essential to move plpar_wrapper.h
to include/asm.
Signed-off-by: Deepthi Dharwar <deepthi@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
The lppaca, slb_shadow and dtl_entry hypervisor structures are
big endian, so we have to byte swap them in little endian builds.
LE KVM hosts will also need to be fixed but for now add an #error
to remind us.
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Address some of the trivial sparse warnings in arch/powerpc.
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Commit 801eb73f45 introduced
a bug while checking PTE flags. We have to drop the _PAGE_COHERENT flag
when __PAGE_NO_CACHE is set and the cache update policy is not write-through
(i.e. _PAGE_WRITETHRU is not set)
Signed-off-by: Denis Kirjanov <kda@linux-powerpc.org>
Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
CC: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
On LPAR systems we need to inform the hypervisor that we are using the
EBB registers. We do this by setting a bit in the Virtual Processor Area
(VPA) - formerly known as the lppaca.
For now we do this always, ie. we do not dynamically enable/disable.
Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Hugepage invalidate involves invalidating multiple hpte entries.
Optimize the operation using H_BULK_REMOVE on lpar platforms.
On native, reduce the number of tlb flush.
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
If a hash bucket gets full, we "evict" a more/less random entry from it.
When we do that we don't invalidate the TLB (hpte_remove) because we assume
the old translation is still technically "valid". This implies that when
we are invalidating or updating pte, even if HPTE entry is not valid
we should do a tlb invalidate. With hugepages, we need to pass the correct
actual page size value for tlb invalidation.
This change update the patch 0608d69246
"powerpc/mm: Always invalidate tlb on hpte invalidate and update" to handle
transparent hugepages correctly.
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
We look at both the segment base page size and actual page size and store
the pte-lp-encodings in an array per base page size.
We also update all relevant functions to take actual page size argument
so that we can use the correct PTE LP encoding in HPTE. This should also
get the basic Multiple Page Size per Segment (MPSS) support. This is needed
to enable THP on ppc64.
[Fixed PR KVM build --BenH]
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Acked-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
PAPR defines these errors as negative values. So print them accordingly
for easy debugging.
Acked-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Some versions of pHyp will perform the adjunct partition test before the
ANDCOND test. The result of this is that H_RESOURCE can be returned and
cause the BUG_ON condition to occur. The HPTE is not removed. So add a
check for H_RESOURCE, it is ok if this HPTE is not removed as
pSeries_lpar_hpte_remove is looking for an HPTE to remove and not a
specific HPTE to remove. So it is ok to just move on to the next slot
and try again.
Cc: stable@vger.kernel.org
Signed-off-by: Michael Wolf <mjw@linux.vnet.ibm.com>
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
This patch convert different functions to take virtual page number
instead of virtual address. Virtual page number is virtual address
shifted right by VPN_SHIFT (12) bits. This enable us to have an
address range of upto 76 bits.
Reviewed-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
It's empty now, apart from other includes.
Fixup a few files that were getting things via this header.
Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
This is no longer selectable, so just remove all the dependent code.
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Tracepoints should not be called inside an rcu_idle_enter/rcu_idle_exit
region. Since pSeries calls H_CEDE in the idle loop, we were violating
this rule.
commit a7b152d534 (powerpc: Tell RCU about idle after hcall tracing)
tried to work around it by delaying the rcu_idle_enter until after we
called the hcall tracepoint, but there are a number of issues with it.
The hcall tracepoint trampoline code is called conditionally when the
tracepoint is enabled. If the tracepoint is not enabled we never call
rcu_idle_enter. The idle_uses_rcu check was also done at compile time
which breaks multiplatform builds.
The simple fix is to avoid tracing H_CEDE and rely on other tracepoints
and the hypervisor dispatch trace log to work out if we called H_CEDE.
This fixes a hang during boot on pSeries.
Signed-off-by: Anton Blanchard <anton@samba.org>
Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
* 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc: (185 commits)
powerpc: fix compile error with 85xx/p1010rdb.c
powerpc: fix compile error with 85xx/p1023_rds.c
powerpc/fsl: add MSI support for the Freescale hypervisor
arch/powerpc/sysdev/fsl_rmu.c: introduce missing kfree
powerpc/fsl: Add support for Integrated Flash Controller
powerpc/fsl: update compatiable on fsl 16550 uart nodes
powerpc/85xx: fix PCI and localbus properties in p1022ds.dts
powerpc/85xx: re-enable ePAPR byte channel driver in corenet32_smp_defconfig
powerpc/fsl: Update defconfigs to enable some standard FSL HW features
powerpc: Add TBI PHY node to first MDIO bus
sbc834x: put full compat string in board match check
powerpc/fsl-pci: Allow 64-bit PCIe devices to DMA to any memory address
powerpc: Fix unpaired probe_hcall_entry and probe_hcall_exit
offb: Fix setting of the pseudo-palette for >8bpp
offb: Add palette hack for qemu "standard vga" framebuffer
offb: Fix bug in calculating requested vram size
powerpc/boot: Change the WARN to INFO for boot wrapper overlap message
powerpc/44x: Fix build error on currituck platform
powerpc/boot: Change the load address for the wrapper to fit the kernel
powerpc/44x: Enable CRASH_DUMP for 440x
...
Fix up a trivial conflict in arch/powerpc/include/asm/cputime.h due to
the additional sparse-checking code for cputime_t.
Unpaired calling of probe_hcall_entry and probe_hcall_exit might happen
as following, which could cause incorrect preempt count.
__trace_hcall_entry => trace_hcall_entry -> probe_hcall_entry =>
get_cpu_var => preempt_disable
__trace_hcall_exit => trace_hcall_exit -> probe_hcall_exit =>
put_cpu_var => preempt_enable
where:
A => B and A -> B means A calls B, but
=> means A will call B through function name, and B will definitely be
called.
-> means A will call B through function pointer, so B might not be
called if the function pointer is not set.
So error happens when only one of probe_hcall_entry and probe_hcall_exit
get called during a hcall.
This patch tries to move the preempt count operations from
probe_hcall_entry and probe_hcall_exit to its callers.
Reported-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: Li Zhong <zhong@linux.vnet.ibm.com>
Tested-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
CC: stable@kernel.org [v2.6.32+]
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
The PowerPC pSeries platform (CONFIG_PPC_PSERIES=y) enables
hypervisor-call tracing for CONFIG_TRACEPOINTS=y kernels. One of the
hypervisor calls that is traced is the H_CEDE call in the idle loop
that tells the hypervisor that this OS instance no longer needs the
current CPU. However, tracing uses RCU, so this combination of kernel
configuration variables needs to avoid telling RCU about the current CPU's
idleness until after the H_CEDE-entry tracing completes on the one hand,
and must tell RCU that the the current CPU is no longer idle before the
H_CEDE-exit tracing starts.
In all other cases, it suffices to inform RCU of CPU idleness upon
idle-loop entry and exit.
This commit makes the required adjustments.
Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
With module.h being implicitly everywhere via device.h, the absence
of explicitly including something for EXPORT_SYMBOL went unnoticed.
Since we are heading to fix things up and clean module.h from the
device.h file, we need to explicitly include these files now.
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Make the VPA, SLB shadow and DTL registration and deregistration
functions print consistent messages on error. I needed the firmware
error code while chasing a kexec bug but we weren't printing it.
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
On a box with 8TB of RAM the MMU hashtable is 64GB in size. That
means we have 4G PTEs. pSeries_lpar_hptab_clear was using a signed
int to store the index which will overflow at 2G.
Signed-off-by: Anton Blanchard <anton@samba.org>
Cc: <stable@kernel.org>
Acked-by: Michael Neuling <mikey@neuling.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
On pseries machines, consoles are provided by the hypervisor using
a low level get_chars/put_chars type interface. However, this is
really just a transport to the service processor which implements
them either as "raw" console (networked consoles, HMC, ...) or as
"hvsi" serial ports.
The later is a simple packet protocol on top of the raw character
interface that is supposed to convey additional "serial port" style
semantics. In practice however, all it does is provide a way to
read the CD line and set/clear our DTR line, that's it.
We currently implement the "raw" protocol as an hvc console backend
(/dev/hvcN) and the "hvsi" protocol using a separate tty driver
(/dev/hvsi0).
However this is quite impractical. The arbitrary difference between
the two type of devices has been a major source of user (and distro)
confusion. Additionally, there's an additional mini -hvsi implementation
in the pseries platform code for our low level debug console and early
boot kernel messages, which means code duplication, though that low
level variant is impractical as it's incapable of doing the initial
protocol negociation to establish the link to the FSP.
This essentially replaces the dedicated hvsi driver and the platform
udbg code completely by extending the existing hvc_vio backend used
in "raw" mode so that:
- It now supports HVSI as well
- We add support for hvc backend providing tiocm{get,set}
- It also provides a udbg interface for early debug and boot console
This is overall less code, though this will only be obvious once we
remove the old "hvsi" driver, which is still available for now. When
the old driver is enabled, the new code still kicks in for the low
level udbg console, replacing the old mini implementation in the platform
code, it just doesn't provide the higher level "hvc" interface.
In addition to producing generally simler code, this has several benefits
over our current situation:
- The user/distro only has to deal with /dev/hvcN for the hypervisor
console, avoiding all sort of confusion that has plagued us in the past
- The tty, kernel and low level debug console all use the same code
base which supports the full protocol establishment process, thus the
console is now available much earlier than it used to be with the
old HVSI driver. The kernel console works much earlier and udbg is
available much earlier too. Hackers can enable a hard coded very-early
debug console as well that works with HVSI (previously that was only
supported for the "raw" mode).
I've tried to keep the same semantics as hvsi relative to how I react
to things like CD changes, with some subtle differences though:
- I clear DTR on close if HUPCL is set
- Current hvsi triggers a hangup if it detects a up->down transition
on CD (you can still open a console with CD down). My new implementation
triggers a hangup if the link to the FSP is severed, and severs it upon
detecting a up->down transition on CD.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
When CONFIG_PPC_EARLY_DEBUG is set, call register_early_udbg_console()
early from generic code.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Adds support for page coalescing, which is a feature on IBM Power servers
which allows for coalescing identical pages between logical partitions.
Hint text pages as coalesce candidates, since they are the most likely
pages to be able to be coalesced between partitions. This patch also
exports some page coalescing statistics available from firmware via
lparcfg.
[BenH: Moved a couple of things around to fix compile problems]
Signed-off-by: Brian King <brking@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Some of the 64bit PPC CPU features are MMU-related, so this patch moves
them to MMU_FTR_ bits. All cpu_has_feature()-style tests are moved to
mmu_has_feature(), and seven feature bits are freed as a result.
Signed-off-by: Matt Evans <matt@ozlabs.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Spinlocks on shared processor partitions use H_YIELD to notify the
hypervisor we are waiting on another virtual CPU. Unfortunately this means
the hcall tracepoints can recurse.
The patch below adds a percpu depth and checks it on both the entry and
exit hcall tracepoints.
Signed-off-by: Anton Blanchard <anton@samba.org>
Acked-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
CC: stable@kernel.org
This introduces a pair of kernel parameters that can be used to disable
the MULTITCE and BULK_REMOVE h-calls.
By default, those hcalls are enabled, active, and good for throughput
and performance. The ability to disable them will be useful for some of
the PREEMPT_RT related investigation and work occurring on Power.
Signed-off-by: Will Schmidt <will_schmidt@vnet.ibm.com>
cc: Olof Johansson <olof@lixom.net>
cc: Anton Blanchard <anton@samba.org>
cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Currently, when CONFIG_VIRT_CPU_ACCOUNTING is enabled, we use the
PURR register for measuring the user and system time used by
processes, as well as other related times such as hardirq and
softirq times. This turns out to be quite confusing for users
because it means that a program will often be measured as taking
less time when run on a multi-threaded processor (SMT2 or SMT4 mode)
than it does when run on a single-threaded processor (ST mode), even
though the program takes longer to finish. The discrepancy is
accounted for as stolen time, which is also confusing, particularly
when there are no other partitions running.
This changes the accounting to use the timebase instead, meaning that
the reported user and system times are the actual number of real-time
seconds that the program was executing on the processor thread,
regardless of which SMT mode the processor is in. Thus a program will
generally show greater user and system times when run on a
multi-threaded processor than on a single-threaded processor.
On pSeries systems on POWER5 or later processors, we measure the
stolen time (time when this partition wasn't running) using the
hypervisor dispatch trace log. We check for new entries in the
log on every entry from user mode and on every transition from
kernel process context to soft or hard IRQ context (i.e. when
account_system_vtime() gets called). So that we can correctly
distinguish time stolen from user time and time stolen from system
time, without having to check the log on every exit to user mode,
we store separate timestamps for exit to user mode and entry from
user mode.
On systems that have a SPURR (POWER6 and POWER7), we read the SPURR
in account_system_vtime() (as before), and then apportion the SPURR
ticks since the last time we read it between scaled user time and
scaled system time according to the relative proportions of user
time and system time over the same interval. This avoids having to
read the SPURR on every kernel entry and exit. On systems that have
PURR but not SPURR (i.e., POWER5), we do the same using the PURR
rather than the SPURR.
This disables the DTL user interface in /sys/debug/kernel/powerpc/dtl
for now since it conflicts with the use of the dispatch trace log
by the time accounting code.
Signed-off-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Currently we have the lppaca structs as a simple array of NR_CPUS
entries, taking up space in the data section of the kernel image.
In future we would like to allocate them dynamically, so this
abstracts out the accesses to the array, making it easier to
change how we locate the lppaca for a given cpu in future.
Specifically, lppaca[cpu] changes to lppaca_of(cpu).
Signed-off-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Currently for kexec the PTE tear down on 1TB segment systems normally
requires 3 hcalls for each PTE removal. On a machine with 32GB of
memory it can take around a minute to remove all the PTEs.
This optimises the path so that we only remove PTEs that are valid.
It also uses the read 4 PTEs at once HCALL. For the common case where
a PTEs is invalid in a 1TB segment, this turns the 3 HCALLs per PTE
down to 1 HCALL per 4 PTEs.
This gives an > 10x speedup in kexec times on PHYP, taking a 32GB
machine from around 1 minute down to a few seconds.
Signed-off-by: Michael Neuling <mikey@neuling.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
While most users of the hcall tracepoints will only want the opcode
and return code, some will want all the arguments. To avoid the
complexity of using varargs we pass a pointer to the register save
area, which contains all the arguments.
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
Add hcall_entry and hcall_exit tracepoints. This replaces the inline
assembly HCALL_STATS code and converts it to use the new tracepoints.
To keep the disabled case as quick as possible, we embed a status word
in the TOC so we can get at it with a single load. By doing so we
keep the overhead at a minimum. Time taken for a null hcall:
No tracepoint code: 135.79 cycles
Disabled tracepoints: 137.95 cycles
For reference, before this patch enabling HCALL_STATS resulted in a null
hcall of 201.44 cycles!
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
pr_debug() can now result in code being generated even when DEBUG
is not defined. That's not really desirable in some places.
In particular, pSeries_lpar_hpte_insert() goes from 185 instructions
to 77 instructions as a result of this patch. Luckily that code
isn't called very often ...
With CONFIG_DYNAMIC_DEBUG=y:
size before:
text data bss dec hex filename
7284 1552 296 9132 23ac platforms/pseries/lpar.o
size after:
text data bss dec hex filename
5806 1096 296 7198 1c1e platforms/pseries/lpar.o
Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Adds support for the "unused" page hint which can be used in shared
memory partitions to flag pages not in use, which will then be stolen
before active pages by the hypervisor when memory needs to be moved to
LPARs in need of additional memory. Failure to mark pages as 'unused'
makes the LPAR slower to give up unused memory to other partitions.
This adds the kernel parameter 'cmo_free_hint' to disable this
functionality.
Signed-off-by: Brian King <brking@linux.vnet.ibm.com>
Signed-off-by: Robert Jennings <rcj@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
It is okay for both _PAGE_GUARDED and _PAGE_COHERENT (G and M) to be set
in the same pte. In fact, even if that were not the case, there doesn't
seem to be any place where G is set without also setting I (_PAGE_NO_CACHE),
so the test for I is sufficient as a condition to clear _PAGE_COHERENT
when filling the hash table.
Signed-off-by: Dave Kleikamp <shaggy@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
The current low level hash code on LPAR configurations clears
_PAGE_COHERENT (M) when either _PAGE_GUARDED (G) or _PAGE_NO_CACHE (I)
is set. This conflicts with _PAGE_SAO which has M, I and W bits sets at
once (normally invalid combo) to indicate the new SAO attribute.
This changes the code to allow that case.
Signed-off-by: Dave Kleikamp <shaggy@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Don't return void in pseries/iommu.c
Make mce_data_buf static in pseries/ras.c
Make things static in pseries/rtasd.c
Make things static in pseries/setup.c
vtermno may as well be static in platforms/pseries/lpar.c
Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Paul Mackerras <paulus@samba.org>
In pseries/lpar.c, fix some printf specifier mismatches, and add
a newline to one printk.
In pseries/rtasd.c add "rtasd" to some messages to make it clear
where they're coming from.
In pseries/scanlog.c remove the hand-rolled runtime debugging support
in there. This file has been largely unchanged for eons, if we need to
debug it in future we can recompile.
Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Paul Mackerras <paulus@samba.org>
On pseries LPAR we can call the udbg routines, and the udbg console very
early. So mark the udbg console as safe to call early in boot, and register
the udbg console as soon as the udbg routines are hooked up.
This allows platforms/pseries code to use printk() and pr_debug() rather
than needing to call udbg_printf() directly for early debugging. This is
nice because a) it's standard, b) it goes via the printk buffer, and c)
you can get printk time stamps.
Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Paul Mackerras <paulus@samba.org>
There is logic in platforms/peries/lpars.c which checks if the user has
specified a console on the command line, and refrains from adding a
preferred console entry for the hvc/hvsi console if they have.
This trips up if you use "netconsole=foo" on the command line, and has
the result that you get _only_ the netconsole, because the hvc device is
never added as a preferred console. Worse still if you get the netconsole
configuration wrong somehow, you end up with no console at all.
As it turns out we don't need to worry about checking the command line.
If the user has specified "console=foo", then foo will be set as the
preferred console when the command line is parsed in start_kernel(), much
later than the pseries code, and so the latter setting will take effect.
Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Paul Mackerras <paulus@samba.org>
Move the prototype for find_udbg_vterm() into pseries.h, removing
it from setup.c.
Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Paul Mackerras <paulus@samba.org>
For memory remove, we need to clean up htab mappings for the
section of the memory we are removing.
This implements support for removing htab bolted mappings for pSeries
logical partitions. Other sub-archs may need to implement similar
functionality for hotplug memory remove to work on them.
Signed-off-by: Badari Pulavarty <pbadari@us.ibm.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
Commit 473980a993 added a call to clear
the SLB shadow buffer before registering it. Unfortunately this means
that we clear out the entries that slb_initialize has previously set in
there. On POWER6, the hypervisor uses the SLB shadow buffer when doing
partition switches, and that means that after the next partition switch,
each non-boot CPU has no SLB entries to map the kernel text and data,
which causes it to crash.
This fixes it by reverting most of 473980a9 and instead clearing the
3rd entry explicitly in slb_initialize. This fixes the problem that
473980a9 was trying to solve, but without breaking POWER6.
Signed-off-by: Paul Mackerras <paulus@samba.org>
Before we register the SLB shadow buffer, we need to invalidate the
entries in the buffer, otherwise we can end up stale entries from when
we previously offlined the CPU.
This does this invalidate as well as unregistering the buffer with
PHYP before we offline the cpu. Tested and fixes crashes seen on
970MP (thanks to tonyb) and POWER5.
Signed-off-by: Michael Neuling <mikey@neuling.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
This makes the kernel use 1TB segments for all kernel mappings and for
user addresses of 1TB and above, on machines which support them
(currently POWER5+, POWER6 and PA6T).
We detect that the machine supports 1TB segments by looking at the
ibm,processor-segment-sizes property in the device tree.
We don't currently use 1TB segments for user addresses < 1T, since
that would effectively prevent 32-bit processes from using huge pages
unless we also had a way to revert to using 256MB segments. That
would be possible but would involve extra complications (such as
keeping track of which segment size was used when HPTEs were inserted)
and is not addressed here.
Parts of this patch were originally written by Ben Herrenschmidt.
Signed-off-by: Paul Mackerras <paulus@samba.org>
This removes several duplicate includes from arch/powerpc/.
Signed-off-by: Jesper Juhl <jesper.juhl@gmail.com>
Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
On Power machines supporting VRMA, Kexec/Kdump does not work.
VRMA (virtual real-mode area) means that accesses with IR/DR = 0
(i.e. the MMU "off") actually still go through the hash table,
using entries put there by the hypervisor.
This means that when we clear out the hash table on kexec, we need to
make sure these entries are left untouched.
This also adds plpar_pte_read_raw() on the lines of
plpar_pte_remove_raw().
Signed-off-by : Sachin Sant <sachinp@in.ibm.com>
Signed-off-by : Mohan Kumar M <mohan@in.ibm.com>
Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Acked-by: Olof Johansson <olof@lixom.net>
Signed-off-by: Paul Mackerras <paulus@samba.org>
for consistency with other Open Firmware interfaces (and Sparc).
This is just a straight replacement.
This leaves the compatibility define in place.
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
kexec invokes plpar_hcall hypervisor call in real mode. plpar_hcall
refers to per cpu variables for accounting hypervisor statistics.
These variables may not be in the RMO region, so accesses to them
in real mode may result in a data storage exception.
This fixes this problem by using a new plpar_hcall_raw function which
does not update the hypervisor call statistics. Thanks to Anton for
suggesting this idea.
Signed-off-by: Mohan Kumar M <mohan@in.ibm.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
