This implements CONFIG_RELOCATABLE for 64-bit by making the kernel as
a position-independent executable (PIE) when it is set.  This involves
processing the dynamic relocations in the image in the early stages of
booting, even if the kernel is being run at the address it is linked at,
since the linker does not necessarily fill in words in the image for
which there are dynamic relocations.  (In fact the linker does fill in
such words for 64-bit executables, though not for 32-bit executables,
so in principle we could avoid calling relocate() entirely when we're
running a 64-bit kernel at the linked address.)

The dynamic relocations are processed by a new function relocate(addr),
where the addr parameter is the virtual address where the image will be
run.  In fact we call it twice; once before calling prom_init, and again
when starting the main kernel.  This means that reloc_offset() returns
0 in prom_init (since it has been relocated to the address it is running
at), which necessitated a few adjustments.

This also changes __va and __pa to use an equivalent definition that is
simpler.  With the relocatable kernel, PAGE_OFFSET and MEMORY_START are
constants (for 64-bit) whereas PHYSICAL_START is a variable (and
KERNELBASE ideally should be too, but isn't yet).

With this, relocatable kernels still copy themselves down to physical
address 0 and run there.
Signed-off-by: NPaul Mackerras <paulus@samba.org>

Kdump kernel needs to use only those memory regions that it is allowed
to use (crashkernel, rtas, tce, etc.).  Each of these regions have
their own sizes and are currently added under 'linux,usable-memory'
property under each memory@xxx node of the device tree.

The ibm,dynamic-memory property of ibm,dynamic-reconfiguration-memory
node (on POWER6) now stores in it the representation for most of the
logical memory blocks with the size of each memory block being a
constant (lmb_size).  If one or more or part of the above mentioned
regions lie under one of the lmb from ibm,dynamic-memory property,
there is a need to identify those regions within the given lmb.

This makes the kernel recognize a new 'linux,drconf-usable-memory'
property added by kexec-tools.  Each entry in this property is of the
form of a count followed by that many (base, size) pairs for the above
mentioned regions.  The number of cells in the count value is given by
the #size-cells property of the root node.
Signed-off-by: NChandru Siddalingappa <chandru@in.ibm.com>
Signed-off-by: NPaul Mackerras <paulus@samba.org>

Add a VSX CPU feature.  Also add code to detect if VSX is available
from the device tree.
Signed-off-by: NMichael Neuling <mikey@neuling.org>
Signed-off-by: NJoel Schopp <jschopp@austin.ibm.com>
Signed-off-by: NPaul Mackerras <paulus@samba.org>

Added support to allow an 85xx kernel to be run from a non-zero physical
address (useful for cooperative asymmetric multiprocessing situations and
kdump).  The support can be configured at compile time by setting
CONFIG_PAGE_OFFSET, CONFIG_KERNEL_START, and CONFIG_PHYSICAL_START as
desired.

Alternatively, the kernel build can set CONFIG_RELOCATABLE.  Setting this
config option causes the kernel to determine at runtime the physical
addresses of CONFIG_PAGE_OFFSET and CONFIG_KERNEL_START.  If
CONFIG_RELOCATABLE is set, then CONFIG_PHYSICAL_START has no meaning.
However, CONFIG_PHYSICAL_START will always be used to set the LOAD program
header physical address field in the resulting ELF image.

Currently we are limited to running at a physical address that is a
multiple of 256M.  This is due to how we map TLBs to cover
lowmem.  This should be fixed to allow 64M or maybe even 16M alignment
in the future.  It is considered an error to try and run a kernel at a
non-aligned physical address.

All the magic for this support is accomplished by proper initialization
of the kernel memory subsystem and use of ARCH_PFN_OFFSET.

The use of ARCH_PFN_OFFSET only affects normal memory and not IO mappings.
ioremap uses map_page and isn't affected by ARCH_PFN_OFFSET.

/dev/mem continues to allow access to any physical address in the system
regardless of how CONFIG_PHYSICAL_START is set.
Signed-off-by: NKumar Gala <galak@kernel.crashing.org>
Signed-off-by: NPaul Mackerras <paulus@samba.org>

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: NBenjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: NPaul 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: NManish Ahuja <mahuja@us.ibm.com>
Signed-off-by: NPaul 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: NGeert Uytterhoeven <Geert.Uytterhoeven@sonycom.com>
Signed-off-by: NPaul 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: NManish Ahuja <mahuja@us.ibm.com>
Signed-off-by: NPaul 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: NManish Ahuja <mahuja@us.ibm.com>
Signed-off-by: NLinas Vepstas <linasvepstas@gmail.com>
Signed-off-by: NPaul 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: NBenjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: NPaul Mackerras <paulus@samba.org>

Signed-off-by: NDavid S. Miller <davem@davemloft.net>

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: NValentine Barshak <vbarshak@ru.mvista.com>
Signed-off-by: NJosh 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: NMichael Neuling <mikey@neuling.org>
Signed-off-by: NPaul 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: NValentine Barshak <vbarshak@ru.mvista.com>
Signed-off-by: NJosh 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: NPaul Mackerras <paulus@samba.org>

Grammatical corrections to comments.
Signed-off-by: NLinas Vepstas <linas@austin.ibm.com>
Signed-off-by: NPaul Mackerras <paulus@samba.org>

Whitespace cleanup: badly indented lines.
Signed-off-by: NLinas Vepstas <linas@austin.ibm.com>
Signed-off-by: NPaul Mackerras <paulus@samba.org>

This removes several duplicate includes from arch/powerpc/.
Signed-off-by: NJesper Juhl <jesper.juhl@gmail.com>
Acked-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: NPaul Mackerras <paulus@samba.org>

...since it modifies it (when it sets the OF_DETACHED flag).
Signed-off-by: NSegher Boessenkool <segher@kernel.crashing.org>
Signed-off-by: NPaul 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: NStephen Rothwell <sfr@canb.auug.org.au>
Acked-by: NPaul Mackerras <paulus@samba.org>
Acked-by: NDavid S. Miller <davem@davemloft.net>

This adds a read_lock around the child/next accesses on Sparc.
Signed-off-by: NStephen Rothwell <sfr@canb.auug.org.au>
Acked-by: NPaul Mackerras <paulus@samba.org>
Acked-by: NDavid 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: NStephen Rothwell <sfr@canb.auug.org.au>
Acked-by: NPaul Mackerras <paulus@samba.org>
Acked-by: NDavid 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: NStephen Rothwell <sfr@canb.auug.org.au>
Acked-by: NPaul Mackerras <paulus@samba.org>
Acked-by: NDavid 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: NStephen Rothwell <sfr@canb.auug.org.au>
Acked-by: NPaul Mackerras <paulus@samba.org>
Acked-by: NDavid 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: NStephen Rothwell <sfr@canb.auug.org.au>
Acked-by: NPaul Mackerras <paulus@samba.org>
Acked-by: NDavid S. Miller <davem@davemloft.net>

Signed-off-by: NMathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NPaul Mackerras <paulus@samba.org>

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: NMichael Ellerman <michael@ellerman.id.au>
Signed-off-by: NPaul 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: NMichael Ellerman <michael@ellerman.id.au>
Signed-off-by: NPaul 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: NMichael Ellerman <michael@ellerman.id.au>
Signed-off-by: NPaul 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: NMichael Ellerman <michael@ellerman.id.au>
Signed-off-by: NPaul 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: NGeoff Levand <geoffrey.levand@am.sony.com>
Signed-off-by: NPaul 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: NMichael Ellerman <michael@ellerman.id.au>
Signed-off-by: NPaul 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: NBenjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: NPaul 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: NMichael Ellerman <michael@ellerman.id.au>
Signed-off-by: NPaul Mackerras <paulus@samba.org>

Replace uses with of_find_node_by_name and for_each_node_by_name.
Signed-off-by: NStephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: NPaul Mackerras <paulus@samba.org>

Replaced by of_find_node_by_type.
Signed-off-by: NStephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: NPaul Mackerras <paulus@samba.org>

Replaced by of_find_node_by_path.
Signed-off-by: NStephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: NPaul Mackerras <paulus@samba.org>

This old interface has no more users.
Signed-off-by: NStephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: NPaul Mackerras <paulus@samba.org>

This is an old interface and is replaced by of_find_compatible_node.
Signed-off-by: NStephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: NPaul Mackerras <paulus@samba.org>

Signed-off-by: NStephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: NPaul Mackerras <paulus@samba.org>