Lockdep found out that we can occasionally take the device-tree
lock for reading from softirq time (from rtas_token called
by the rtas real time clock code called by the NTP code),
while we take it occasionally for writing without masking
interrupts. The combination of those two can thus deadlock.
While some of those cases of interrupt read lock could be fixed
(such as caching the RTAS tokens) I figured that taking the
lock for writing is so rare (device-tree modification) that we
may as well penalize that case and allow reading from interrupts.
Thus, this turns all the writers to take the lock with irqs
masked to avoid the situation.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
This changes the way we calculate how much space to reserve for the
pHyp dump. Currently we reserve 256MB only. With this change, the
code first checks to see if an amount has been specified on the boot
command line with the "phyp_dump_reserve_size" option, and if so, uses
that much.
Otherwise it computes 5% of total ram and rounds it down to a multiple
of 256MB, and uses the larger of that or 256MB.
This is for large systems with a lot of memory (10GB or more). The
aim is to have more space available for the kernel on reboot on
machines with more resources. Although the dump will be collected
pretty fast and the memory released really early on allowing the
machine to have the full memory available, this alleviates any issues
that can be caused by having way too little memory on very very large
systems during those few minutes.
Signed-off-by: Manish Ahuja <mahuja@us.ibm.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
WARNING: vmlinux.o(.text+0x1e4c0): Section mismatch in reference from the
function .move_device_tree() to the function .init.text:.lmb_alloc_base()
The function .move_device_tree() references
the function __init .lmb_alloc_base().
This is often because .move_device_tree lacks a __init
annotation or the annotation of .lmb_alloc_base is wrong.
move_device_tree() is called from early_init_devtree() only, which is __init
Signed-off-by: Geert Uytterhoeven <Geert.Uytterhoeven@sonycom.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
This adds a kernel command line option "phyp_dump", which takes a 0/1
value for disabling/ enabling phyp_dump at boot time. Kdump can use
this on cmdline (phyp_dump=0) to disable phyp-dump during boot when
enabling itself. This will ensure only one dumping mechanism is active
at any given time.
Signed-off-by: Manish Ahuja <mahuja@us.ibm.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
Initial patch for reserving memory in early boot, and freeing it
later. If the previous boot had ended with a crash, the reserved
memory would contain a copy of the crashed kernel data.
Signed-off-by: Manish Ahuja <mahuja@us.ibm.com>
Signed-off-by: Linas Vepstas <linasvepstas@gmail.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
dt_mem_next_cell() currently does of_read_ulong(). This does not
allow for the case where #size-cells and/or #address-cells = 2 on a
32-bit system, as it will end up reading 32 bits instead of the
expected 64. Change it to use of_read_number instead and always
return a u64.
Signed-off-by: Becky Bruce <becky.bruce at freescale.com>
Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
Renaming the CPU nodes with generic names put the CPU model in
the "model" property and thus broke the PowerPC 440EP(x)/440GR(x)
identical PVR workaround. The updates it to use the new model property
for CPU identification.
Signed-off-by: Valentine Barshak <vbarshak@ru.mvista.com>
Signed-off-by: Josh Boyer <jwboyer@linux.vnet.ibm.com>
Currently we hardwire the number of SLBs to 64, but PAPR says we
should use the ibm,slb-size property to obtain the number of SLB
entries. This uses this property instead of assuming 64. If no
property is found, we assume 64 entries as before.
This soft patches the SLB handler, so it shouldn't change performance
at all.
Signed-off-by: Michael Neuling <mikey@neuling.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
PowerPC 440EP(x) 440GR(x) processors have the same PVR values, since
they have identical cores. However, FPU is not supported on GR(x) and
enabling APU instruction broadcast in the CCR0 register (to enable FPU)
may cause unpredictable results. There's no safe way to detect FPU
support at runtime. This patch provides a workarund for the issue.
We use a POWER6 "logical PVR approach". First, we identify all EP(x)
and GR(x) processors as GR(x) ones (which is safe). Then we check
the device tree cpu path. If we have a EP(x) processor entry,
we call identify_cpu again with PVR | 0x8. This bit is always 0
in the real PVR. This way we enable FPU only for 440EP(x).
Signed-off-by: Valentine Barshak <vbarshak@ru.mvista.com>
Signed-off-by: Josh Boyer <jwboyer@linux.vnet.ibm.com>
Discussions with firmware architects have confirmed that the bit in
the ibm,pa-features property that indicates support for
cache-inhibited large (>= 64kB) page mappings does in fact mean that
the hypervisor allows 64kB mappings to I/O devices.
Thus we can now enable the code that tests that bit and sets our
CPU_FTR_CI_LARGE_PAGE feature bit.
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>
...since it modifies it (when it sets the OF_DETACHED flag).
Signed-off-by: Segher Boessenkool <segher@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
This consolidates the routines of_find_node_by_path, of_find_node_by_name,
of_find_node_by_type and of_find_compatible_device. Again, the comparison
of strings are done differently by Sparc and PowerPC and also these add
read_locks around the iterations.
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Acked-by: Paul Mackerras <paulus@samba.org>
Acked-by: David S. Miller <davem@davemloft.net>
This adds a read_lock around the child/next accesses on Sparc.
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Acked-by: Paul Mackerras <paulus@samba.org>
Acked-by: David S. Miller <davem@davemloft.net>
This requires creating dummy of_node_{get,put} routines for sparc and
sparc64. It also adds a read_lock around the parent accesses.
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Acked-by: Paul Mackerras <paulus@samba.org>
Acked-by: David S. Miller <davem@davemloft.net>
The only change here is that a readlock is taken while the property list
is being traversed on Sparc where it was not taken previously.
Also, Sparc uses strcasecmp to compare property names while PowerPC
uses strcmp.
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Acked-by: Paul Mackerras <paulus@samba.org>
Acked-by: David S. Miller <davem@davemloft.net>
The only difference here is that Sparc uses strncmp to match compatibility
names while PowerPC uses strncasecmp.
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Acked-by: Paul Mackerras <paulus@samba.org>
Acked-by: David S. Miller <davem@davemloft.net>
This creates drivers/of/base.c (depending on CONFIG_OF) and puts
the first trivially common bits from the prom.c files into it.
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Acked-by: Paul Mackerras <paulus@samba.org>
Acked-by: David S. Miller <davem@davemloft.net>
The prom.c debugging code creates a "powerpc" directory in debugfs,
which is nice, but doesn't allow any other debugging code to stick things
under "powerpc" in debugfs. So make it global.
While we're there we should make the prom.c debugging code depend on
CONFIG_DEBUG_FS, because it doesn't work otherwise.
Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Paul Mackerras <paulus@samba.org>
When the refcount for a device node goes to 0, we call the
destructor - of_node_release(). This should only happen if we've
already detached the node from the device tree.
So add a flag OF_DETACHED which tracks detached-ness, and if we
find ourselves in of_node_release() without it set, issue a
warning and don't free the device_node. To avoid warning
continuously reinitialise the kref to a sane value.
Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Paul Mackerras <paulus@samba.org>
The struct device_node currently has a _flags variable, although
it's only used for one flag - OF_DYNAMIC. Generalise the flag
accessors so we can use them with other flags in future.
Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Paul Mackerras <paulus@samba.org>
It's not sensible to call of_detach_node() on the root node,
but we should check for it just to be safe.
Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Paul Mackerras <paulus@samba.org>
Add a printout of the params value to early_init_devtree.
This value is handy to have for comparison when debugging the
bootwrapper code.
Signed-off-by: Geoff Levand <geoffrey.levand@am.sony.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
The documentation for of_find_node_by_type() incorrectly refers to the
"name" parameter - it should be "type".
Also the behaviour when from == NULL is not really documented, fix that.
Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Paul Mackerras <paulus@samba.org>
Our device-tree unflattening code makes sure the name and type fields
of a device-node are not NULL. However, the code for dynamically
adding devices nodes which is used for pSeries hotplug for example
didn't do it, potentially causing crashes in some code that assume it
can always do things like strcmp on those.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
If CONFIG_BLK_DEV_INITRD is not defined the prop variable in
early_init_dt_scan_chosen() is unused, causing a compiler warning.
So split the initrd logic into a separate function, allowing us to
declare prop only when we need it.
Built for both cases and booted with an initrd.
Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Paul Mackerras <paulus@samba.org>
Replace uses with of_find_node_by_name and for_each_node_by_name.
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Paul Mackerras <paulus@samba.org>
This is an old interface and is replaced by of_find_compatible_node.
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Paul Mackerras <paulus@samba.org>
This is more consistent and gets us closer to the Sparc code.
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Paul Mackerras <paulus@samba.org>
This is more consistent and gets us closer to the Sparc code.
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Paul Mackerras <paulus@samba.org>
This is more consistent and gets us closer to the Sparc code.
We add a device_is_compatible define for compatibility during the
change over.
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Paul Mackerras <paulus@samba.org>
This is more consistent and gets us closer to the Sparc code.
We add a get_property define for compatibility during the change over.
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Paul Mackerras <paulus@samba.org>
At present, when an initrd is passed to the kernel used flat device
tree properties, the memory the initrd occupies must also be reserved
in the flat tree's reserve map, or the kernel may overwrite it. That
makes life more complicated than it could be for the bootwrapper.
This patch makes the kernel automatically reserve the initrd's space.
That in turn requires parsing the initrd parameters earlier than they
are currently, in early_init_dt_scan_chosen() instead of
check_for_initrd().
Signed-off-by: David Gibson <dwg@au1.ibm.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
At present calling lmb_reserve() (and hence lmb_add_region()) twice
for exactly the same memory region will cause strange behaviour.
This makes life difficult when booting from a flat device tree with
memory reserve map. Which regions are automatically reserved by the
kernel has changed over time, so it's quite possible a newer kernel
could attempt to auto-reserve a region which is also explicitly listed
in the device tree's reserve map, leading to trouble.
This patch avoids the problem by making lmb_reserve() ignore a call to
reserve a previously reserved region. It also removes a now redundant
test designed to avoid one specific case of the problem noted above.
At present, this patch deals only with duplicate reservations of an
identical region. Attempting to reserve two different, but
overlapping regions will still cause problems. I might post another
patch later dealing with this case, but I'm avoiding it now since it
is substantially more complicated to deal with, less likely to occur
and more likely to indicate a genuine bug elsewhere if it does occur.
Signed-off-by: David Gibson <dwg@au1.ibm.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
Without this, building drivers/serial/of_serial.c as a module fails.
WARNING: ".of_find_property" [drivers/serial/of_serial.ko] undefined!
Signed-off-by: Dave Jones <davej@redhat.com>
Acked-by: Arnd Bergmann <arnd.bergmann@de.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
For PAPR partitions with large amounts of memory, the firmware has an
alternative, more compact representation for the information about the
memory in the partition and its NUMA associativity information. This
adds the code to the kernel to parse this alternative representation.
The other part of this patch is telling the firmware that we can
handle the alternative representation. There is however a subtlety
here, because the firmware will invoke a reboot if the memory
representation we request is different from the representation that
firmware is currently using. This is because firmware can't change
the representation on the fly. Further, some firmware versions used
on POWER5+ machines have a bug where this reboot leaves the machine
with an altered value of load-base, which will prevent any kernel
booting until it is reset to the normal value (0x4000). Because of
this bug, we do NOT set fake_elf.rpanote.new_mem_def = 1, and thus we
do not request the new representation on POWER5+ and earlier machines.
We do request the new representation on POWER6, which uses the
ibm,client-architecture-support call.
Signed-off-by: Paul Mackerras <paulus@samba.org>
This adds code to look at the properties firmware puts in the device
tree to determine what compatibility mode the partition is in on
POWER6 machines, and set the ELF aux vector AT_HWCAP and AT_PLATFORM
entries appropriately.
Specifically, we look at the cpu-version property in the cpu node(s).
If that contains a "logical" PVR value (of the form 0x0f00000x), we
call identify_cpu again with this PVR value. A value of 0x0f000001
indicates the partition is in POWER5+ compatibility mode, and a value
of 0x0f000002 indicates "POWER6 architected" mode, with various
extensions disabled. We also look for various other properties:
ibm,dfp, ibm,purr and ibm,spurr.
Signed-off-by: Paul Mackerras <paulus@samba.org>
This patch adds a cpufreq backend driver to enable frequency scaling on cell.
Signed-off-by: Christian Krafft <krafft@de.ibm.com>
Signed-off-by: Arnd Bergmann <arnd.bergmann@de.ibm.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
