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: Kumar Gala <galak@kernel.crashing.org>
Signed-off-by: Paul 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: 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>
...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 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>
